EXHIBIT 10.41





                              INVESTMENT AGREEMENT

                                  by and among

                              MOTIENT CORPORATION,

                         MOTIENT SATELLITE VENTURES LLC,


                                       and

                           THE INVESTORS NAMED HEREIN

                                   dated as of

                                  June 22, 2000





                                Table of Contents

                                                                            Page

Section 1. Newco Interests.....................................................1

       1.1.         The Purchase...............................................1
       1.2.         The Initial Closing........................................1
       1.3.         Conditions to Initial Closing..............................2

Section 2. Investors Option....................................................6

       2.1.         Grant of Option............................................6
       2.2.         Exercise of Option.........................................6
       2.3.         Conditions to Investors Option Closing.....................9
       2.4.         Payment and Issuance of Interests.........................12
       2.5.         Sub Offer.................................................12

Section 3. Parent Conversions.................................................13

       3.1.         Parent Conversions........................................13

Section 4. Representations and Warranties of Parent...........................14

       4.1.         Organization and Good Standing; Power and
                    Authority; Qualifications.................................15
       4.2.         Authorization of the Documents............................15
       4.3.         Capitalization............................................15
       4.4.         Authorization and Issuance of Parent Capital
                    Stock and Investor Interests..............................16
       4.5.         SEC and Other Documents; Financial Statements.............16
       4.6.         No Undisclosed Liabilities................................17
       4.7.         Absence of Certain Changes or Events......................17
       4.8.         No Conflict...............................................17
       4.9.         Litigation; Orders........................................18
       4.10.        Compliance with Laws; Permits.............................18
       4.11.        Offering Exemption........................................19
       4.12.        Consents..................................................19
       4.13.        Brokers...................................................19
       4.14.        Public Utility Holding Company, Etc.......................19
       4.15.        FCC.......................................................20
       4.16.        Sub Representations and Warranties........................21
       4.17.        Restrictions..............................................21
       4.18.        Newco Activities..........................................21
       4.19.        Disclosure................................................21

Section 5. Representations and Warranties of the Investors....................21

       5.1.         Investment Representations................................21
       5.2.         Organization and Good Standing; Power and Authority.......22



       5.3.         Authorization of Documents................................22
       5.4.         No Conflict...............................................23
       5.5.         Litigation; Orders........................................23
       5.6.         Compliance with Laws; Permits.............................23
       5.7.         Consents..................................................23
       5.8.         Brokers...................................................24
       5.9.         Appointment of Investor Group Designees...................24

Section 6. Representations and Warranties of Parent and Newco.................24

       6.1.         Organization and Good Standing; Power and
                    Authority; Qualifications.................................24
       6.2.         Authorization of the Documents............................25
       6.3.         Capitalization............................................25
       6.4.         Authorization and Issuance of Investor Interests..........25
       6.5.         Financial Statements......................................25
       6.6.         No Undisclosed Liabilities................................25
       6.7.         Absence of Certain Changes or Events......................26
       6.8.         No Conflict...............................................26
       6.9.         Litigation; Orders........................................26
       6.10.        Compliance with Laws; Permits.............................26
       6.11.        Title.....................................................27
       6.12.        ERISA Matters.............................................27
       6.13.        Insurance.................................................27
       6.14.        Labor Relations; Employees................................27
       6.15.        Agreements................................................27
       6.16.        Offering Exemption........................................28
       6.17.        Consents..................................................28
       6.18.        Brokers...................................................28
       6.19.        Public Utility Holding Company, Etc.......................28
       6.20.        FCC.......................................................29
       6.21.        Restrictions..............................................29
       6.22.        Sub Representations and Warranties........................30
       6.23.        Environmental Matters.....................................30
       6.24.        Proprietary Rights........................................30
       6.25.        Disclosure................................................31

Section 7. Certain Covenants..................................................31

       7.1.         Notification of Certain Matters...........................31
       7.2.         Hart Scott-Rodino Filing..................................31
       7.3.         Affirmative Covenants.....................................31
       7.4.         Certain Additional Covenants..............................32
       7.5.         Transactions with Affiliates..............................33
       7.6.         Reservation of Common Stock...............................33
       7.7.         Use of Proceeds...........................................33
       7.8.         Financial Information.....................................33



       7.9.         Survival of Representations, Warranties, Agreements
                    and Covenants; Indemnifications...........................34

Section 8. Termination........................................................37

       8.1.         Termination...............................................37
       8.2.         Parent Common Stock Purchase Option.......................37

Section 9. Further Assurances.................................................38


Section 10. Successors and Assigns............................................38


Section 11. Entire Agreement..................................................39


Section 12. Notices.......................................................... 39


Section 13. Amendments........................................................40


Section 14. Counterparts......................................................40


Section 15. Headings..........................................................40


Section 16. Nouns and Pronouns................................................40


Section 17. Governing Law.....................................................40


Section 18. Publicity.........................................................41


Section 19. Severability......................................................41


Section 20. Expenses..........................................................41






                                    Schedules

Schedule I........                  Investors


Disclosure Schedule:

Section 4.1                         Subsidiaries
Section 4.3(a)                      Parent's Capitalization
Section 4.5(a)                      SEC and Other Documents
Section 4.6                         No Undisclosed Liabilities
Section 4.7                         Absence of Certain Changes or Events
Section 4.8                         Conflicts
Section 4.9                         Litigation; Disputes
Section 4.10                        Compliance with Laws; Permits
Section 4.12                        Consents
Section 4.15                        FCC

Newco Disclosure Schedule:

Section 6.20                        FCC
Section 6.24                        Proprietary Rights









                                    Exhibits

Exhibit A  -                                Certificate

Exhibit B  -                                LLC Operating Agreement

Exhibit C  -                                Registration Rights Agreement

Exhibit D  -                                Research and Development Agreement

Exhibit E  -                                Cross-Licensing Agreement

Exhibit F  -                                Asset Sale Agreement

Exhibit G  -                                Opinion of Counsel to Parent (FCC)

Exhibit H  -                                Merger Agreement




                              INVESTMENT AGREEMENT

                  INVESTMENT  AGREEMENT,  dated as of June 22, 2000 by and among
MOTIENT  CORPORATION,  a  Delaware  corporation  ("Parent"),  MOTIENT  SATELLITE
VENTURES LLC, a Delaware limited  liability company of which Parent is currently
the sole member ("Newco"), and each of the investors listed on Schedule I hereto
(each, an "Investor" and collectively, the "Investors").

                              W I T N E S S E T H :
                               - - - - - - - - - -


                  WHEREAS,  Motient Services Inc., a Delaware corporation and an
indirect wholly-owned  subsidiary of Parent ("Sub"), has been issued licenses by
the  Federal   Communications   Commission  (the  "FCC")  to  provide  satellite
communications  services (such licenses,  together with the satellite and ground
assets, the "Existing Business") in the United States and surrounding waters and
airspace in the 1530-1559 Mhz and 1631.5-1660.5 Mhz band;

                  WHEREAS,  the parties  hereto wish for the Investors to invest
in Newco, for Newco to acquire the Existing  Business,  and for Newco,  with the
assistance and  cooperation of the Investors,  to explore ways of maximizing the
use of the Existing Business, including modifications thereto.

                  NOW, THEREFORE, the parties hereto hereby agree as follows:

Section 1.        Newco Interests.
                  ---------------

1.1. The Purchase.  At the Initial Closing,  each Investor shall,  severally and
not jointly,  purchase from Newco,  and Newco shall sell to such  Investor,  the
interest in Newco (collectively,  the "Investor  Interests")  described opposite
such  Investor's name on Schedule I for the purchase price indicated on Schedule
I, which shall result in an aggregate purchase price to be paid by the Investors
for all of the Investor  Interests  to be  purchased  at the Initial  Closing of
Fifty Million Dollars  ($50,000,000)  (the "Initial  Investment").  The Investor
Interests to be acquired for the Initial Investment will represent (as reflected
more fully in the LLC Operating Agreement, as defined below) in the aggregate an
interest in the profits and losses of Newco (a "Newco  Percentage  Interest") of
20%, with Parent then having a Newco Percentage Interest of 80%.

1.2.     The Initial Closing.
         -------------------

(a) The closing of the  transactions  contemplated  by Section 1.1 (the "Initial
Closing")  shall  take  place at the  offices  of  Dewey  Ballantine  LLP,  1775
Pennsylvania Avenue NW, Washington,  DC 20006 at 10:00 a.m., on or prior to June
30, 2000, or on such other date as shall be mutually agreed by Parent, Newco and
the Investors (the "Initial Closing Date").

(b) At the Initial  Closing,  Newco shall  deliver to each  Investor an executed
copy of the LLC Operating  Agreement (as defined below)  evidencing the Investor
Interest  purchased by such Investor,  against receipt at the Initial Closing by
Newco from such Investor of 50% of its portion of the Initial Investment,  which
shall be paid by wire  transfer to an account  designated in writing by Newco at
least three business days prior to the Initial  Closing.  If the Initial Closing
shall occur,  then on or before July 14, 2000,  each Investor shall pay to Newco
the remaining  50% of its portion of the Initial  Investment by wire transfer as
contemplated  by the  preceding  sentence,  time  being of the  essence.  If any
Investor shall fail to make the payment  contemplated by the preceding  sentence
(or shall fail to participate in the Initial Closing), the other Investors shall
have the pro rata right (but not the  obligation)  to make up for the  resulting
shortfall,  in which  case the  defaulting  Investor  shall  be  deemed  to have
consented to the Investor Interests being re-allocated appropriately.

1.3.     Conditions to Initial Closing.
         -----------------------------

(a)  Conditions  to the  Obligations  of Parent,  Newco and the  Investors.  The
obligations of Parent,  Newco and the Investors to consummate  the  transactions
contemplated  by  Section  1.1  at  the  Initial  Closing  are  subject  to  the
satisfaction of the following conditions: no ruling, order, injunction,  decree,
statute,  rule or regulation  of any  governmental  authority  shall prevent the
consummation of the transactions  contemplated hereby;  provided,  however, that
the parties  shall use their  reasonable  best efforts to cause any such decree,
ruling, injunction or other order to be vacated or lifted.

(b)  Conditions to the  Obligations of the  Investors.  The  obligations of each
Investor  to  consummate  the  transactions  contemplated  by Section 1.1 at the
Initial  Closing are  subject to the  satisfaction  or waiver,  on or before the
Initial Closing Date, of the following additional conditions:

     (i)   Representations,    Warranties   and   Covenants   of   Parent.   The
     representations  and  warranties  of Parent  set forth in Section 4 of this
     Agreement shall be true and correct in all material respects as of the date
     when  made and  (unless  made as of a  specified  date)  as of the  Initial
     Closing Date;  provided,  however,  that if any of the  representations and
     warranties  are already  qualified in any respect by  materiality  or as to
     Material Adverse Effect,  such representation or warranty shall be true and
     correct as of such dates in all respects  (i.e.,  as  written);  and Parent
     shall  have  performed,  and shall have  caused  Newco to  perform,  in all
     material respects their respective covenants set forth in this Agreement to
     be performed prior to or at the Initial Closing; provided, however, that if
     any of the covenants are already qualified in any respect by materiality or
     as to Material  Adverse Effect,  such covenant shall have been performed in
     all respects  (i.e.,  as written);  and neither Parent nor Newco shall have
     taken any action which would violate any provision of Newco's LLC Operating
     Agreement (as defined below) or this Agreement,  as the case may be, and at
     the Initial  Closing  Parent  shall  deliver to each  Investor an officer's
     certificate,  dated  the  Initial  Closing  Date  and duly  executed  by an
     executive officer, certifying as to Parent's compliance with the conditions
     set forth in this clause (i) and in clauses (ii),  (viii),  (xiii),  (xiv),
     (xv) and (xviii);

     (ii) Certificate.  Newco shall have adopted and filed with the Secretary of
     State of the State of Delaware  the  Certificate  of  Formation in the form
     attached hereto as Exhibit A (the "Certificate");

     (iii) LLC Operating Agreement.  Parent, Newco and each other Investor shall
     have executed and delivered to such Investor an LLC Operating  Agreement in
     substantially the form of Exhibit B hereto (the "LLC Operating Agreement");

     (iv)  Registration  Rights  Agreement.   Parent  shall  have  executed  and
     delivered to such Investor a Registration Rights Agreement in substantially
     the  form of  Exhibit  C  hereto  (the  "Registration  Rights  Agreement");

     (v) Research and Development  Agreement.  Newco and Sub shall have executed
     and delivered the Research & Development,  Marketing and Service  Agreement
     substantially in the form of Exhibit D hereto (the ---------- "Research and
     Development Agreement");

     (vi)  Cross-Licensing  Agreement.  Newco,  Sub and  Motient  Communications
     Company  ("Motient  Communications")  shall have executed and delivered the
     Cross-Licensing  and Bulk  Resale  Agreement  substantially  in the form of
     Exhibit E hereto (the "Cross-Licensing Agreement");

     (vii) Other Agreements. Parent and the persons or entities that control the
     Investors shall have entered into (i) the letter agreement  contemplated by
     Section 2.1 hereof (the  "Section 2.1 Letter") and (ii) a letter  agreement
     relating  to  certain  transfers  of  interests  in  the  Investors  and of
     interests in Newco (the "Parent Transfer Letter Agreement");

     (viii)  Asset  Sale  Agreement.  Newco  and Sub  shall  have  executed  and
     delivered the Asset Sale Agreement  substantially  in the form of Exhibit F
     hereto, (the "Asset Sale Agreement" and, together with the Certificate, LLC
     Operating   Agreement,   Registration   Rights   Agreement,   Research  and
     Development  Agreement,  the  Cross-Licensing  Agreement,  the  Section 2.1
     Letter  and  the  Parent   Transfer   Letter   Agreement,   the  "Ancillary
     Agreements");

     (ix) Opinions of Counsel to Parent.  Such  Investor  shall have received an
     opinion  of  FCC  counsel  to  Parent,  dated  the  Initial  Closing  Date,
     substantially  in the form of Exhibit G and  opinions  of counsel to Parent
     reasonably  satisfactory  to such  Investor with respect to the matters set
     forth in Sections 4.1, 4.2, 4.3, 4.4, 4.8, 4.9, 4.10,  4.11, 4.12, 4.14 and
     4.17 hereto;

     (x) Board of  Directors  of  Newco.  Newco  shall  have  delivered  to such
     Investor evidence that the number of directors  comprising Newco's board of
     directors has been fixed at seven and that the three persons  designated by
     the Investors shall have been elected to such board;

     (xi)  Good  Standing  Certificates.  Newco  shall  have  delivered  to such
     Investor a copy of a certificate of good  standing,  dated as of a date not
     earlier  than five days  prior to the  Initial  Closing,  from the State of
     Delaware and the Commonwealth of Virginia;

     (xii) Secretary's Certificates.  Parent, Newco and Sub shall have delivered
     to such Investor  certificates  executed by their  respective  Secretaries,
     dated the Initial Closing Date, each certifying (A) in the case of Newco, a
     copy of its  organizational  documents,  (B)  resolutions of its respective
     Board of  Directors  or  Board of  Managers  authorizing  the  transactions
     contemplated  hereby  and  by  the  Ancillary  Agreements,  (C)  incumbency
     matters,  and (D) such other  proceedings  relating  to the  authorization,
     execution and delivery of this Agreement,  the Ancillary Agreements and the
     transactions contemplated hereby and thereby as may be reasonably requested
     by Telcom Satellite Ventures Inc. (the "Lead Investor");

     (xiii) No Pending  Action.  No  action,  suit,  investigation,  proceeding,
     temporary  restraining order,  preliminary or permanent injunction or other
     order or  decree  shall be  pending  or  threatened  in any  court or other
     tribunal or before any arbitrator or governmental authority which (i) could
     have a  Material  Adverse  Effect (as  defined  in Section  4.6) on Parent,
     Newco,  Sub  or  the  Existing  Business  or  (ii)  seeks  to  prevent  the
     consummation of the  transactions  contemplated  hereby or by the Ancillary
     Agreements and is material in nature;

     (xiv)  Consents and Approvals.  Parent,  Sub, Newco and each Investor shall
     have received all  governmental,  shareholder  and third party consents and
     approvals  (including  the  consents  of  lenders)  necessary  or,  in  the
     reasonable judgment of the Lead Investor,  desirable in connection with the
     transactions  contemplated hereby and by the Ancillary Agreements including
     the expiration or  termination  of any applicable  waiting period under the
     Hart-Scott-Rodino Antitrust Improvements Act of 1976 (the "HSR Act");

     (xv) No Material  Adverse  Effect.  No Material  Adverse  Effect shall have
     occurred,  nor  shall  any event or events  have  occurred  which  would be
     reasonably  likely to have a  Material  Adverse  Effect,  with  respect  to
     Parent, Newco, Sub or the Existing Business;

     (xvi) Other Documents.  Parent,  Newco and Sub shall have delivered to such
     Investor  such  other  documents  as  counsel  to  the  Lead  Investor  may
     reasonably request;

     (xvii)  Other  Investors.  Each other  Investor  shall be prepared to close
     simultaneously; and

     (xviii) Loan  Obligations.  Sub shall have no obligation under the terms of
     any loan agreements or financing documents to apply more than $6 million of
     the $44  million in payments  to be  received  by it  (consisting  of a $20
     million  Service  Fee  payable  pursuant to the  Research  and  Development
     Agreement  and a $24  million  Deposit  payable  pursuant to the Asset Sale
     Agreement) to the repayment of indebtedness,  and upon  consummation of the
     transactions  to be  consummated  at or  simultaneously  with  the  Initial
     Closing  (and  giving  effect to the  funding  contemplated  by the  second
     sentence  of  Section  1.2(b)),  Parent  shall  have at least  $38  million
     available to it for working  capital,  capital  expenditures and payment of
     expenses in connection with the transactions contemplated hereby and by the
     Ancillary Agreements.

(c) Conditions to the Obligations of Parent and Newco. The obligations of Parent
and Newco to  consummate  the  transactions  contemplated  by Section 1.1 at the
Initial  Closing are  subject to the  satisfaction  or waiver,  on or before the
Initial Closing Date, of the following additional conditions:

     (i)  Representations,  Warranties  and  Covenants  of  the  Investors.  The
     representations  and  warranties of each Investor set forth in Section 5 of
     this Agreement shall be true and correct in all material respects as of the
     date when made and (unless  made as of a specified  date) as of the Initial
     Closing Date;  provided,  however,  that if any of the  representations and
     warranties  are already  qualified in any respect by  materiality  or as to
     Material Adverse Effect,  such representation or warranty shall be true and
     correct as of such  dates in all  respects  (i.e.,  as  written);  and each
     Investor shall have performed,  in all material  respects its covenants set
     forth in this Agreement to be performed prior to or at the Initial Closing;
     provided,  however,  that if any of the covenants are already  qualified in
     any respect by materiality or as to Material Adverse Effect,  such covenant
     shall have been performed in all respects  (i.e.,  as written);  and at the
     Initial   Closing  each  Investor   shall   deliver  to  Parent   officer's
     certificates,  dated  the  Initial  Closing  Date and duly  executed  by an
     executive  officer,  certifying as to such  Investor's  compliance with the
     conditions set forth in this clause (i) and in clauses (iv) and (v);

     (ii) LLC  Operating  Agreement.  Each  Investor  shall  have  executed  and
     delivered to Parent and Newco the LLC Operating Agreement;

     (iii)  Secretary's  Certificates.  Each  Investor  shall have  delivered to
     Parent a certificate  executed by its Secretary,  dated the Initial Closing
     Date,  certifying (A) resolutions of its Board of Directors authorizing the
     transactions  contemplated  herein,  (B) incumbency  matters,  and (C) such
     other proceedings relating to the authorization,  execution and delivery of
     this Agreement, the Ancillary Agreements and the transactions  contemplated
     hereby and thereby as may be reasonably requested by Parent;

     (iv)  No  Pending  Action.  No  action,  suit,  investigation,  proceeding,
     temporary  restraining order,  preliminary or permanent injunction or other
     order or  decree  shall be  pending  or  threatened  in any  court or other
     tribunal or before any arbitrator or governmental authority which (i) could
     have a Material  Adverse Effect on an Investor's  ability to consummate the
     transactions  contemplated  by this  Agreement or (ii) seeks to prevent the
     consummation  of the  transactions  contemplated  hereby and is material in
     nature;

     (v) Consents and Approvals. Parent, Sub, Newco and the Investors shall have
     received  all  governmental,  shareholder  and  third  party  consents  and
     approvals  (including  consents of lenders) necessary or, in the reasonable
     judgment  of  Parent,   desirable  in  connection  with  the   transactions
     contemplated  hereby  and  by  the  Ancillary   Agreements   including  the
     expiration or termination  of any  applicable  waiting period under the HSR
     Act; and

     (vi)  Investors.  Each of the Investors shall be prepared to close and fund
     its share of the Initial Investment.

Section 2.        Investors Option.
                  ----------------

2.1.  Grant of Option.  Subject to the terms and  conditions  set forth  herein,
Newco hereby  grants to the  Investors  an  irrevocable  option (the  "Investors
Option")  to  increase  their  Newco  Percentage  Interest  by, in total for all
Investors,  40% (e.g.,  from 20% to 60%), as  contemplated by Section 4.1 of the
LLC Operating  Agreement,  and to receive an aggregate of 40 Investor  Units (as
defined in the LLC Operating  Agreement) for a price (the "Option Price") of (i)
$120,000,000 if the Investors Option shall be exercised on or prior to the first
anniversary of the Initial Closing Date, or (ii)  $120,000,000 plus $118,356 per
day for each day between the first  anniversary of the Initial  Closing Date and
the Investment Commitment Date (as defined below), if the Investors Option shall
be exercised  after the first  anniversary  of the Initial  Closing Date. If the
Investors  Option is  exercised by one or more  Investors  who,  following  such
exercise,  would,  collectively,  hold a Newco Percentage  Interest of less than
50.1% as a result of less than all  Investors  exercising  or as a result of any
dilution to the Investor  Interests  resulting from any issuance by Newco to the
entities listed in the letter agreement dated the date hereof between Parent and
the Investors  prior to the exercise of the  Investors  Option of an interest in
Newco (but,  for avoidance of doubt,  not including as a result of a decrease in
the Newco Percentage Interest held by Exercising  Investor(s) (as defined below)
resulting  from sales of Newco  Percentage  Interests by them to persons who are
not Exercising Investor(s)), such Exercising Investor(s) shall have the right to
increase  the Newco  Percentage  Interest  to be acquired  upon  exercise of the
Investors  Option  to such  percentage  as  would  be  necessary  to  give  such
Exercising  Investor(s) a Newco Percentage Interest of 50.1%, for a proportional
increase in the Option Price. For illustrative  purposes only, if the Exercising
Investor(s)  owned a 9.1% aggregate  Newco  Percentage  Interest,  they would be
entitled to acquire an aggregate additional Newco Percentage Interest of 41% (41
Investor  Units) for a purchase price of  $123,000,000,  assuming the Investment
Commitment  Date occurred prior to the first  anniversary of the Initial Closing
Date.  Unless the parties hereto  otherwise  agree,  nothing in this Section 2.1
shall grant the Investors the right to increase their Newco Percentage  Interest
to more than 60%.

2.2.     Exercise of Option.
         ------------------

(a) The Investors  Option may be exercised  once in whole but not in part by any
one or  more of the  Investors  (the  "Exercising  Investor(s)")  by  delivering
written  notice of exercise to Newco (the "Option  Notice," the date of delivery
of which is  referred  to as the  "Option  Notice  Date") at any time  after the
Initial  Closing Date and on or prior to the later of (x) second  anniversary of
the Initial  Closing  Date and (y) if there shall be an extension of the Outside
Date pursuant to Section 8.8 of the Asset Sale Agreement, the date to which such
Outside Date is extended (the "Exercise Period"). Notwithstanding the foregoing,
no Investor may exercise the Investors  Option (or  participate  in the exercise
thereof)  unless such  Investor  either (i) is an Accredited  Investor,  or (ii)
delivers  to Newco an opinion of counsel to the effect  that such  Investor  may
acquire an additional  interest in Newco without the necessity of a registration
under the  Securities  Act of 1933, as amended (the  "Securities  Act") or under
applicable state securities laws.

(b) The Investors  agree among  themselves that if any one or more of them shall
propose to exercise the Investors  Option, it or they shall give at least twenty
(20) days'  prior  notice  thereof to each  other  Investor  who shall then be a
member of Newco.  Any Investor that shall wish to  participate  in such exercise
shall be permitted to do so on a pro rata basis (allocating the Newco Percentage
Interest to be acquired upon such exercise,  and the Option Price,  on the basis
of the Newco Percentage  Interest then held by each such participating  Investor
relative  to the  Newco  Percentage  Interests  then  held by all  participating
Investors).  Notwithstanding  the  foregoing,  except in the case of an Offer as
contemplated  by Section 2.5, no Investor may exercise the Investor Option prior
to the 547th day after the Initial  Closing unless such Investor,  together with
other Investors that propose to participate in such exercise, or that consent to
such exercise,  hold at least 50.1% of the Newco Percentage  Interests then held
by all Investors.  Upon the exercise of the Investors Option,  all Investors who
are then members of Newco other than  Investors  participating  in the Investors
Option shall be deemed to have requested a Parent  Conversion (as defined below)
in accordance  with Section 3.1, and to have delivered a Conversion  Notice upon
the  Option  Notice  Date,   which  Parent   Conversion   shall  be  consummated
simultaneously  with the later of the Investors  Option  Closing or the earliest
date on which the rights granted by Section 3.1(a) may be exercised.

(c) Upon receipt of the Option Notice, Newco shall, and Parent shall cause Newco
to, provide the Exercising  Investor(s) and their representatives full access to
all premises, properties, officers, directors, consultants,  contractors, books,
records   (including,   without  limitation,   tax  returns,   tax  records  and
correspondence  with  accountants),  contracts and  documents  pertaining to its
business as the Exercising Investor(s) deem necessary (the "Due Diligence"), and
the Exercising  Investor(s)  and their  representatives  shall have the right to
copy such books, records, contracts and documents at the Exercising Investor(s)'
expense. Newco shall, and Parent shall cause Newco to, cooperate fully with such
Investors  and their  representatives  in  permitting  reasonable  access to its
business to conduct the Due  Diligence.  Such access may be either during normal
business  hours or after normal  business  hours after the giving of  reasonably
advance notice to Newco. The Exercising Investor(s) shall reasonably restore any
property  of Newco  damaged as a result of the Due  Diligence  to its  condition
prior to any such Due  Diligence  and shall  indemnify and defend Newco from any
and all  liability  which  may  arise  as a  result  of the  performance  of Due
Diligence by the Exercising  Investor(s).  Newco will furnish to each Exercising
Investor and its  representatives  such  financial and operating  data and other
information  as to Newco (and, to the extent  available to Newco,  as to Sub) as
such Exercising Investor may reasonably request, including,  without limitation,
financial statements,  books and records and agreements with clients, customers,
vendors, lessors, licensors and suppliers of the Existing Business.

(d) Within ten (10)  business days  following  the Option  Notice Date,  each of
Parent  and Newco  shall,  and  Parent  shall  cause  Newco to,  provide to each
Exercising  Investor a certificate of a senior  executive  officer of Parent and
Newco,  respectively,   making  on  behalf  of  Parent  and  Newco  the  various
representations and warranties set forth in Section 6 of this Agreement and such
other   representations  and  warranties  as  the  Exercising   Investor(s)  may
reasonably  request  (except that Parent and Newco shall not be required to make
any such additional representations and warranties as to any matters as to which
the pertinent  information is not reasonably  available to them),  together with
disclosure  schedules  updating  the  information  in the  Disclosure  Schedules
delivered  herewith and taking any necessary  exceptions to the  representations
and  warranties  not  being  made  as of the  date  hereof,  all as of the  date
delivered to each Investor (the "Newco Update Date"). As to representations  and
warranties  made on the Newco Update Date which are parallel to  representations
and  warranties  made on the date hereof  pursuant to Section 4, the  Disclosure
Schedules  delivered on the Newco Update Date shall be updates of the Disclosure
Schedules  delivered herewith,  adding relevant  information as to any pertinent
developments or changes since the date hereof.  As to other  representation  and
warranties  made on the Newco Update Date,  the  Disclosure  Schedules  shall be
prepared by Parent and Newco in good faith to reflect as fairly as possible  the
nature and scope of  exceptions  that the  parties  hereto  have  agreed upon in
connection with the Disclosure Schedules delivered herewith.

(e)  Within ten  business  (10) days  following  the Option  Notice  Date,  each
Exercising Investor shall provide to each of Parent and Newco a certificate of a
senior executive officer of such Exercising Investor, remaking on behalf of such
Exercising  Investor the various  representations  and  warranties  set forth in
Section 5 of this  Agreement,  together with  disclosure  schedules  showing any
additional necessary  exceptions to such representations and warranties,  all as
of the Newco Update Date.

(f) Beginning on the Option Notice Date and ending ten (10) days after the Newco
Update  Date,  any  Exercising  Investor  shall have the right to withdraw  from
participation in the exercise of the Investor Option by providing written notice
to Newco and the other  Exercising  Investor(s)  of such  Exercising  Investor's
decision to withdraw, in which case the withdrawing Exercising Investor shall be
deemed to have requested a Parent Conversion, and to have delivered a Conversion
Notice  on the  date  of such  withdrawal,  which  Parent  Conversion  shall  be
consummated as contemplated  by the last sentence of Section  2.2(b).  Following
the expiration of the withdrawal period specified in the previous sentence,  any
non-withdrawing  Exercising  Investor(s)  shall have an additional five business
(5) day  period in which  they shall  each  decide  whether to proceed  with the
exercise  or to revoke the  Exercise  Notice.  If one or more of the  Exercising
Investor(s)  elects to proceed with the exercise of the Investors  Option,  such
Investor(s)  shall  proceed to consummate  the Investors  Option as set forth in
this Section 2 as though they were the only Investors originally  exercising the
Investors  Option,  including,  but not limited to, the right to increase  their
Newco  Percentage  Interest in accordance with Section 2.1 and the allocation of
percentage  interests to be acquired and Option Price in accordance with Section
2.2. If all Exercising Investor(s) withdraw, the Exercise Notice shall be deemed
revoked and the Investors  Option shall be deemed not to have been exercised for
any purpose hereunder (including the first sentence of Section 2.2(a)).

(g) Following  the  expiration of the  withdrawal  periods  specified in Section
2.2(f) or, in the event the  Exercising  Investor(s)  provide  written notice to
Newco that they waive the remainder of the  withdrawal  periods,  on the date of
such notice (the date of such notice or waiver is referred to as the "Investment
Commitment Date"),  Parent, Newco and the Exercising  Investor(s) shall take all
commercially  reasonable  action  to  promptly  consummate  the  closing  of the
exercise of the Investors Option (the "Investors Option Closing").  Such date on
which the Investors  Option Closing shall occur is referred to as the "Investors
Option Closing Date". Without limiting the generality of the foregoing, if prior
notification  or approval of any regulatory  authority is required in connection
with such purchase,  the Exercising  Investor(s)  and, if applicable,  Newco and
Parent shall promptly file the required  notice or application  for approval and
shall expeditiously process the same (and Newco and Parent, shall cooperate with
the Exercising  Investor(s) in the filing of any such notice or application  and
the obtaining of any such approval).

(h) During the period from the Option  Notice Date to the date of the  Investors
Option  Closing,  Parent shall cause Newco to conduct its business and engage in
transactions  only in the  ordinary  course  of  business  consistent  with past
practice.

2.3.     Conditions to Investors Option Closing.
         --------------------------------------

(a)  Conditions  to  the  Obligations  of  Parent,   Newco  and  the  Exercising
Investor(s).  The obligations of Parent, Newco and the Exercising Investor(s) to
consummate the transactions  contemplated by Section 2.1 at the Investors Option
Closing are subject to the satisfaction of the following conditions:  no ruling,
order,  injunction,  decree,  statute,  rule or regulation  of any  governmental
authority  shall  prevent  the  consummation  of the  transactions  contemplated
hereby;  provided,  however,  that the parties shall use their  reasonable  best
efforts  to cause  any such  decree,  ruling,  injunction  or other  order to be
vacated or lifted.

(b) Conditions to the Obligations of the Exercising Investor(s). The obligations
of each  Exercising  Investor to consummate  the  transactions  contemplated  by
Section 2.1 at the Investors  Option Closing are subject to the  satisfaction or
waiver,  on or before  the  Investors  Option  Closing  Date,  of the  following
additional conditions:

          (i) Representations, Warranties and Covenants of Parent and Newco. The
     representations  and  warranties of Parent and Newco set forth in Section 6
     of this  Agreement and such other  representations  and  warranties as were
     made  pursuant to Section  2.2(d) shall be true and correct in all material
     respects as of the Newco Update Date and as of the Investors Option Closing
     Date,  subject to the updated  disclosure  schedules prepared in accordance
     with Section 2.2(d); provided,  however, that if any of the representations
     and warranties are already qualified in any respect by materiality or as to
     Material Adverse Effect,  such representation or warranty shall be true and
     correct as of such dates in all respects (i.e., as written); and Parent and
     Newco shall have each  performed,  and Parent  shall have  caused  Newco to
     perform,  in all material respects their respective  covenants set forth in
     this Agreement to be performed prior to or at the Investors Option Closing;
     provided,  however,  that if any of the covenants are already  qualified in
     any respect by materiality or as to Material Adverse Effect,  such covenant
     shall have been performed in all respects (i.e.,  as written);  and neither
     Parent  nor Newco  shall have taken any  action  which  have  violated  any
     provision of Newco's Certificate or this Agreement, as the case may be, and
     at the Investors Option Closing Parent and Newco shall each deliver to each
     Investor  officer's  certificates,  dated the Investors Option Closing Date
     and duly  executed by an executive  officer,  certifying as to Parent's and
     Newco's  compliance with the conditions set forth in this clause (i) and in
     clauses (v), (vi), (vii) and (viii);

          (ii) Opinions of Counsel to Parent.  Each  Exercising  Investor  shall
     have received an opinion of counsel to Parent,  dated the Investors  Option
     Closing  Date,  substantially  in the form of  Exhibit  G and  opinions  of
     counsel  to Parent and Newco  reasonably  satisfactory  to such  Exercising
     Investor  with respect to the matters set forth in Sections  6.1, 6.2, 6.3,
     6.4, 6.8, 6.9, 6.10, 6.16, 6.17, 6.19 and 6.21 hereto;

          (iii) Good Standing  Certificates.  Newco shall have delivered to each
     Exercising Investor a certificate of good standing,  dated as of a date not
     earlier  than five days prior to the  Investors  Option  Closing,  from the
     State of Delaware and each other state in which Newco transacts business;

          (iv) Secretary's  Certificates.  Parent and Newco shall have delivered
     to each  Exercising  Investor  certificates  executed  by their  respective
     Secretaries,  dated the Investors  Option Closing Date, each certifying (A)
     in  the  case  of  Newco,  a  copy  of its  organizational  documents,  (B)
     resolutions  of  its  respective   Board  of  Directors   authorizing   the
     transactions  contemplated  hereby  and by the  Ancillary  Agreements,  (C)
     incumbency  matters,  and  (D)  such  other  proceedings  relating  to  the
     authorization,  execution  and delivery of this  Agreement,  the  Ancillary
     Agreements and the transactions  contemplated  hereby and thereby as may be
     reasonably requested by such Exercising Investor(s);

          (v) No Pending Action.  No action,  suit,  investigation,  proceeding,
     temporary  restraining order,  preliminary or permanent injunction or other
     order or  decree  shall be  pending  or  threatened  in any  court or other
     tribunal or before any arbitrator or governmental authority which (i) could
     have a  Material  Adverse  Effect on  Parent,  Newco,  Sub or the  Existing
     Business  or (ii) seeks to prevent  the  consummation  of the  transactions
     contemplated hereby, and is material in nature;

          (vi) Consents and Approvals. Parent, Sub and Newco shall have received
     all  governmental,  shareholder  and third  party  consents  and  approvals
     (including  the consents of lenders) and the Exercising  Investor(s)  shall
     have  received  all  governmental  consents  and  approvals,  in each case,
     necessary  or, in the  reasonable  judgment  of such  Exercising  Investor,
     desirable in connection with the  transactions  contemplated  hereby and by
     the Ancillary  Agreements  including the  expiration or  termination of any
     applicable waiting period under the HSR Act;

          (vii) No Material  Adverse  Effect.  No Material  Adverse Effect shall
     have  occurred  during the period  between  the Newco  Update  Date and the
     Investors Option Closing, nor shall any event or events have occurred which
     would be reasonably  likely to have a Material  Adverse  Effect during such
     period, with respect to Parent, Newco, Sub or the Existing Business;

          (viii) Simultaneous Closing.  Simultaneously with the Investors Option
     Closing,  the  closing  of  the  acquisition  by  Newco  of  the  Satellite
     Communications  Business (as defined in the Asset Sale Agreement)  pursuant
     to the Asset Sale Agreement shall take place;

          (ix) Other  Documents.  Parent,  Newco and Sub shall have delivered to
     each Exercising Investor such other documents as counsel to such Exercising
     Investor may reasonably request; and

          (x) Other Exercising  Investors.  Each Other Exercising Investor shall
     be prepared to close simultaneously.

(c) Conditions to the Obligations of Parent and Newco. The obligations of Parent
and Newco to  consummate  the  transactions  contemplated  by Section 2.1 at the
Investors Option Closing are subject to the satisfaction or waiver, on or before
the Investors Option Closing Date, of the following additional conditions:

          (i)  Representations,  Warranties  and  Covenants  of  the  Exercising
     Investors.  The  representations and warranties of each Exercising Investor
     set forth in Section 5 of this  Agreement  shall be true and correct in all
     material  respects  as of the  date  when  made  and  (unless  made as of a
     specified  date) as of the Investors  Option  Closing Date,  subject to the
     updated  disclosure  schedules prepared in accordance with Section 2.2(e) ;
     provided,  however,  that if any of the  representations and warranties are
     already  qualified in any respect by materiality or as to Material  Adverse
     Effect,  such  representation  or warranty  shall be true and correct as of
     such dates in all respects (i.e., as written); and the Exercising Investors
     shall have performed,  in all material respects,  their covenants set forth
     in this  Agreement  to be  performed  prior to or at the  Investors  Option
     Closing;  provided,  however,  that  if any of the  covenants  are  already
     qualified in any respect by materiality or as to Material  Adverse  Effect,
     such covenant shall have been performed in all respects (i.e., as written);
     and at the Investors  Option  Closing each Investor shall deliver to Parent
     officer's  certificates,  dated the Investors  Option Closing Date and duly
     executed  by  an  executive  officer,  certifying  as  to  such  Exercising
     Investor's  compliance with the conditions set forth in this clause (i) and
     in clause (iii);

          (ii)  Secretary's  Certificates.  Each Exercising  Investor shall have
     delivered  to Parent a  certificate  executed by its  Secretary,  dated the
     Investors  Option Closing Date,  certifying (A) resolutions of its Board of
     Directors authorizing the transactions  contemplated herein, (B) incumbency
     matters,  and  (C)  such  other  corporate  proceedings  relating  to  this
     Agreement,  the  Ancillary  Agreements  and the  transactions  contemplated
     hereby and thereby as may be reasonably requested by Parent;

          (iii) Consents and Approvals.  The Exercising  Investor(s) and Parent,
     Sub and Newco shall have received all governmental  consents and approvals,
     in each case, necessary in connection with the transactions contemplated by
     this Section 2 including the  expiration or  termination  of any applicable
     waiting period under the HSR Act.

          (iv)  Payment of Initial  Investment.  The entire  Initial  Investment
     shall have been paid to Newco.

(d) If the Investors  Option  Closing shall not occur due to a failure of any of
the  conditions  listed in Section  2.3(b),  then the  Exercise  Notice shall be
deemed  revoked  and the  Investors  Option  shall be  deemed  not to have  been
exercised for any purpose  hereunder  (including  the first  sentence of Section
2.2(a)).

2.4.     Payment and Issuance of Interests.
         ---------------------------------

(a) At the Investors Option Closing,  each Exercising Investor will pay to Newco
in immediately  available funds by wire transfer to a bank account designated in
writing by Newco at least three days prior to the  Investors  Option  Closing an
amount  equal  to such  Investor's  proportional  amount  of the  Option  Price;
provided,  that  failure or refusal of Newco to  designate  such a bank  account
shall not preclude the Investors from exercising the Investors Option.

(b) At the  Investors  Option  Closing,  simultaneously  with  the  delivery  of
immediately  available funds as provided in Section 2.4(a),  Newco will deliver,
or cause to be delivered to each Exercising Investor, evidence that the Investor
Interests to be purchased by such Investor at the Investors  Option Closing have
been duly issued,  which Investor  Interests will be validly issued and free and
clear of all mortgages, liens, pledges, encumbrances,  security interests, deeds
of trust, options,  encroachments,  reservations,  orders,  decrees,  judgments,
conditions,  restrictions,  charges, agreements,  claims or equities of any kind
("Encumbrances")  (except for any such Encumbrance due to applicable federal and
state  securities  laws and  Encumbrances  arising  from acts of the  Exercising
Investors).

2.5.     Sub Offer.
         ---------

(a) In the event that  following the first  anniversary  of the Initial  Closing
Date and prior to the  earlier  of (i)  expiration  of the  Investors  Option in
accordance with its terms and (ii) exercise of the Investors  Option,  Parent or
Sub shall receive a bona fide offer that Parent  reasonably  believes is capable
of being  consummated on the terms proposed,  and that Parent or Sub proposes to
accept (an "Offer") from any unaffiliated third party (the "Offeror") to acquire
all or substantially  all of the assets of, or otherwise a substantial  interest
(by means of a stock purchase,  merger,  business  combination or otherwise) in,
Sub or the Existing Business,  other than a transaction of the type contemplated
by Section  7.4(b),  Parent shall give written  notice (the "Offer  Notice," the
date of receipt of which is  referred  to as the  "Offer  Notice  Date") to each
Investor  Group  Designee (as defined  below) of such Offer,  which notice shall
contain a reasonably detailed description of the proposed transaction, including
the identity of the Offeror (including any known  affiliates),  a description of
the consideration to be received in respect thereof and a description of all the
material terms of the Offer.  Until the 60th day after the Offer Notice Date, no
action shall be taken by Parent, Sub, Newco or any of their affiliates to accept
the Offer or to create any  obligation  to the  Offeror in respect of the Offer.
If, on or prior to such 60th day, one or more of the Investors deliver an Option
Notice,  Parent, Sub and Newco shall continue to refrain from pursuing the Offer
and shall proceed in accordance with Section 2.2 hereof.

(b) In the event that no Investor shall have delivered an Option Notice prior to
the 60th day after the Offer  Notice  Date,  Parent and Sub may accept the Offer
and consummate  the  transactions  contemplated  thereby on terms not materially
less  favorable to Parent and Sub than the terms  contained in the Offer Notice;
provided  that Parent shall give the  Investors  not more than ten nor less than
five business days notice of the closing of the transactions contemplated by the
Offer (the "Offer Closing  Notice Date"),  and within three business days of the
Offer Closing  Notice Date,  the Investors  shall elect in writing to either (i)
effect the Parent  Conversions  in accordance  with Section 3.1,  simultaneously
with or promptly  following such closing or (ii)  liquidate  Newco in accordance
with Section 13.1 of the LLC Operating  Agreement,  in which case Parent and Sub
may not  consummate  the  transactions  contemplated  by the Offer  unless prior
thereto or  simultaneously  therewith  Sub shall refund to Newco the $44 million
paid  to Sub  pursuant  to  the  Asset  Sale  Agreement  and  the  Research  and
Development Agreement.

Section 3.        Parent Conversions.
                  ------------------

3.1.     Parent Conversions.
         ------------------

(a) Each of the three  Investor  Groups as described on Schedule I hereto (each,
an "Investor  Group") shall have a right at any time during the Exercise Period,
upon written  notice (the  "Conversion  Notice") to Parent by the Investor Group
Designee  designated  on Schedule I hereto  relating to such  Investor  Group an
"Investor Group Designee"),  to require,  and upon receipt of such notice Parent
shall cause and do all things necessary  (including  preparing and filing within
15 days after  receipt of such notice all  required  documents  and  filings) to
obtain all third-party or government  consents,  approvals and authorizations as
may be necessary or advisable,  to, as promptly as practicable  (but in no event
later than the latest of (i) the  expiration or  termination  of any  applicable
waiting period under the HSR Act, (ii) the receipt of all necessary  third party
or governmental  consents,  authorizations  or approvals and (iii) 15 days after
receipt of such notice) either,  at the option of each Investor in such Investor
Group, (i) cause a Delaware direct wholly-owned  corporate  subsidiary of Parent
to merge,  in a  reorganization  intended  to be  tax-free,  into such  Investor
pursuant to a merger  agreement  substantially  in the form  attached  hereto as
Exhibit H (each,  a "Parent  Merger");  provided that such  Investor  shall be a
corporation  permitted  under  applicable  law and its governing  instruments to
effectuate a Parent Merger and shall have  represented  and warranted  that such
Investor has no assets or liabilities other than the Investor  Interests held by
it and its  rights  and  obligations  under  this  Agreement  and the  Ancillary
Agreements or (ii) exchange  shares of common stock,  par value $0.01 per share,
of  Parent  ("Parent  Common  Stock)  for the  Investor  Interests  held by such
Investor (each, a "Parent  Exchange" and together with the Parent  Mergers,  the
"Parent Conversions").  In each Parent Merger, the capital stock of the Investor
shall be  converted  into  shares of Parent  Common  Stock,  and in each  Parent
Exchange,  the Newco Interest held by the Investor shall be exchanged for Parent
Common  Stock,  in each case with the number of shares of Parent Common Stock to
be issued to be  determined  by dividing  the  original  purchase  price for the
interest in Newco held by such  Investor (A) by $12, if the Closing  Price as of
the date of delivery of the Conversion  Notice (the "Notice  Closing  Price") is
less than or equal to $24,  (B) by $20, if the Notice  Closing  Price is greater
than or equal to $40, or (C) if the Notice Closing Price is greater than $24 and
less than $40,  then by such  number  equal to  one-half  of the Notice  Closing
Price,  as the case may be;  provided,  however,  that no  Investor  Group shall
exercise  such rights  pursuant  to this  Section 3.1 until the earlier of (i) 6
months  after  the  Initial  Closing  or (ii) a Parent  Extraordinary  Event (as
defined below). In the event Parent is excused from registering shares of Parent
Common  Stock on Forms S-4 as  contemplated  by  Section  3 of the  Registration
Rights  Agreement,  an  Investor  which has not been  deemed to make an election
hereunder  pursuant to Section 2.2(b) or Section 2.2(f) may delay the closing of
the  Parent  Conversion  until  such  registration  is  available  or revoke its
election  with  respect to the Parent  Conversion,  in which case such  election
shall be deemed not to have been exercised for any purpose hereunder.

(b) For  purposes of this  Agreement,  "Closing  Price" means as of any date and
subject to  adjustment  in the event of a stock split,  stock  dividend or other
recapitalization  of Parent (i) if shares of Parent Common Stock are listed on a
national securities  exchange,  the average of the closing sale prices per share
therefor on the largest  securities  exchange on which such shares are traded on
the last twenty  (20)  trading  days  before such date,  (ii) if such shares are
listed  on The  Nasdaq  National  Market  but  not on  any  national  securities
exchange,  the average of the closing bid and asked prices per share therefor on
The Nasdaq  National  Market on the last  twenty (20)  trading  days before such
date,  or (iii) if such  shares are not  listed on either a national  securities
exchange or The Nasdaq National Market, the average of the closing bid and asked
prices per share therefor in the over the counter market on the last thirty (30)
trading  days  before  such date.  For  purposes  of this  Agreement,  a "Parent
Extraordinary Event" shall mean (i) Parent shall have effected any merger (other
than  a  merger   done   solely  to  effect  a  change  in   domicile  or  other
non-substantive transaction), amalgamation, corporate reorganization or business
combination  or sale or  conveyance  of its  assets,  property or business as an
entirety  or  substantially  as an  entirety  or  shall  have  entered  into any
agreement to, or announced an intention to, effect any of the foregoing, or (ii)
any party shall have  commenced  or  announced an intention to commence a tender
offer,  proxy  contest  or  similar  transaction  with the  purpose or effect of
effecting a change of control of Parent.

(c) If there shall be any consolidation or merger to which Parent is a party, or
any sale or conveyance of the property of Parent as an entirety or substantially
as an entirety (any such event being called a "Parent Capital  Reorganization"),
then,  effective upon the effective date of such Parent Capital  Reorganization,
the Investors shall have the right to receive in the Parent  Conversion the kind
and amount of shares of stock and other securities and property (including cash)
which the Investors  would have been entitled to receive in connection with such
Parent  Capital  Reorganization  if the  Parent  Conversion  had  been  effected
immediately  prior to such Parent  Capital  Reorganization.  As a  condition  to
effecting  any  Parent  Capital  Reorganization,  Parent  or  the  successor  or
surviving  corporation,  as the case may be,  shall  execute and deliver to each
Investor an  agreement  as to such  Investor's  rights in  accordance  with this
Section  3.1(c).  The provisions of this Section 3.1(c) shall similarly apply to
successive Parent Capital Reorganizations.

(d) To the extent not  theretofore  exercised,  the Investors shall be deemed to
have waived  their  rights under this Section 3.1 when and in the event that Sub
shall have  irreversibly  refunded  to Newco the Refund (as defined in the Asset
Sale Agreement) following an election made by Newco to receive such Refund under
Section 8.8, 8.9 or 8.10 of the Asset Sale  Agreement.  If Newco shall have made
an election to receive the Refund  Amount under Section 8.8 or 8.10 of the Asset
Sale  Agreement,  the Investors'  right to effect a Parent  Conversion  shall be
suspended for 60 days from the date of such election.

Section 4. Representations and Warranties of Parent.  Except as disclosed in the
disclosure schedule delivered by Parent to the Investors and incorporated herein
(the "Disclosure Schedule"),  Parent hereby represents and warrants to Newco and
the Investors as follows:

4.1. Organization and Good Standing; Power and Authority;  Qualifications.  Each
of Parent and Newco (a) is duly organized, validly existing and in good standing
under the laws of its  jurisdiction  of  organization  and (b) has all requisite
corporate or limited  liability  company power and  authority to own,  lease and
operate its properties and to carry on its business as presently conducted. Each
of Parent  and Newco has all  requisite  power and  authority  to enter into and
carry out the  transactions  contemplated  by this  Agreement  and the Ancillary
Agreements  to which it is a party.  Newco  has  filed to  become  qualified  to
transact business as a foreign limited liability company in, and Parent knows of
no  reason  that  Newco  will not be in good  standing  under  the laws of,  the
Commonwealth  of Virginia.  Section 4.1 of the Disclosure  Schedule sets forth a
complete  list of  each  Subsidiary  of  Parent.  As  used  in  this  Agreement,
"Subsidiary"  means an entity that is directly or indirectly  controlled  by, or
more than 50% owned by, another entity.

4.2. Authorization of the Documents. The execution,  delivery and performance by
Parent and Newco of this Agreement and each of the Ancillary Agreements to which
it is a party, and the consummation of the transactions  contemplated hereby and
thereby  have  been  duly  authorized  by all  requisite  corporate  or  limited
liability  company action on the part of Parent and Newco,  respectively (and do
not or will not require the approval or consent of the  shareholders of Parent),
and this  Agreement  and each of the  Ancillary  Agreements  when  executed will
constitute a legal,  valid and binding  obligation  of each of Parent and Newco,
enforceable  against Parent and Newco in accordance with its terms except to the
extent that  enforceability  may be limited by  bankruptcy,  insolvency or other
similar laws affecting creditors' rights generally and except to the extent that
the remedy of specific  performance  and injunction and other forms of equitable
relief may be subject to  equitable  defenses.  As of the Initial  Closing,  the
Cross Licensing Agreement will have been duly authorized, executed and delivered
by Motient Communications and will be the legal, valid and binding obligation of
Motient  Communications,  enforceable  against it in  accordance  with its terms
except  to  the  extent  that  enforceability  may  be  limited  by  bankruptcy,
insolvency  or other  similar laws  affecting  creditors'  rights  generally and
except to the extent that the remedy of specific  performance and injunction and
other forms of equitable relief may be subject to equitable defenses.

4.3.     Capitalization.
         --------------

(a)  Parent.  The  authorized  capitalization  of Parent  as of the date  hereof
consists of: (i) 200,000 shares of preferred  stock,  par value $0.01 per share,
none of which are issued and outstanding,  and (ii) 150,000,000 shares of Parent
Common Stock, of which 49,506,308  shares were issued and outstanding as of June
19, 2000.  Since June 19, 2000,  no shares of capital  stock of Parent have been
issued except pursuant to the exercise of options  outstanding on June 19, 2000.
All such  outstanding  shares of Parent Common Stock are validly  issued,  fully
paid and nonassessable.  The information set forth on the  capitalization  table
set forth in  Section  4.3(a) of the  Disclosure  Schedule,  including,  without
limitation, the information regarding the outstanding options to purchase Parent
Common Stock and fully diluted share  information is true,  correct and complete
as of June 19,  2000.  Except  as  listed in  Section  4.3(a) of the  Disclosure
Schedule, there are no outstanding options, warrants, subscription rights, calls
or commitments of any character  whatsoever relating to, or securities or rights
convertible into, shares of any class of capital stock of Parent  (collectively,
"Parent  Options"),  or by which  Parent  or any of its  subsidiaries  is or may
become  bound  to issue  additional  shares  of its  capital  stock or  options,
warrants or other rights to purchase or acquire any shares of its capital  stock
or other rights, agreements or commitments which obligate the Parent to register
any shares of its capital stock.

(b) Newco.  Immediately  prior to the Initial Closing,  the sole member of Newco
will be, and the only  interest  in Newco will be held by,  Parent.  Immediately
after the Initial  Closing,  the ownership of Newco shall be as set forth in the
LLC Operating Agreement.  All such outstanding interests will be validly issued.
Except pursuant to the LLC Operating  Agreement,  no member of Newco is entitled
to pre-emptive rights.  Except for the Investors Option granted to the Investors
pursuant to Section 2.1 of this Agreement,  there are not now and will not as of
the Initial Closing be, any outstanding options, warrants,  subscription rights,
calls or  commitments of any character  whatsoever  relating to, or interests or
rights  convertible  into, or  exchangeable  for,  interests of any character of
Newco,  or by which Newco is or may become bound to issue  additional  interests
(collectively, "Newco Options"). Newco has not, since its inception, declared or
paid any dividend or made any other  distribution  of cash or other  property to
its members.

4.4.  Authorization and Issuance of Parent Capital Stock and Investor Interests.
The  authorization,  issuance,  sale  and  delivery  of the  Investor  Interests
pursuant to this Agreement and the authorization,  reservation,  issuance,  sale
and delivery of Parent Common Stock pursuant to the Parent  Conversions  and the
Parent Common Stock Purchase  Option have been duly  authorized by all requisite
limited  liability  company or corporate action on the part of Newco and Parent,
as the case may be, and when issued,  sold and delivered in accordance with this
Agreement,  the (i) Investor  Interests will be validly  issued and  outstanding
with no personal  liability  attaching to the ownership  thereof  (other than as
provided in the  Delaware  Limited  Liability  Company  Act) and (ii) the Parent
Common  Stock  will  be  validly   issued  and   outstanding,   fully  paid  and
nonassessable with no personal liability attaching to ownership thereof, in each
case,  free and clear of any  Encumbrances,  other  than  Encumbrances,  if any,
arising as a result of actions  taken by the  Investors  or arising  pursuant to
applicable  federal and state  securities laws, and not subject to preemptive or
similar rights of members or stockholders of Newco, Parent or others. The terms,
designations,  powers,  preferences  and  relative,  optional and other  special
rights, and the  qualifications,  limitations and restrictions,  of the Investor
Interests  are as  stated in the LLC  Operating  Agreement.  As of the  Closing,
Parent has  reserved a  sufficient  number of shares of Parent  Common Stock for
issuance upon the exercise of the Parent Common Stock Purchase Option and in the
event of the Parent Conversions.

4.5.     SEC and Other Documents; Financial Statements.
         ---------------------------------------------

(a) Parent has delivered or made  available to the Investors  each  registration
statement,  report,  proxy statement or information  statement and all exhibits,
amendments  and  supplements  thereto  filed with the  Securities  and  Exchange
Commission  ("SEC") since January 1, 2000, which are listed in Section 4.5(a) of
the Disclosure Schedule, each in the form (including exhibits and any amendments
and supplements  thereto) filed with the SEC  (collectively,  including any such
reports filed subsequent to the date hereof,  the "Parent  Reports").  Except as
set forth in Section 4.5(a) of the Disclosure Schedule,  the Parent Reports were
filed with the SEC in a timely  manner and  constitute  all forms,  reports  and
documents  required to be filed by the Company  under the  Securities  Act,  the
Securities  Exchange Act of 1934, as amended (the "Exchange  Act") and the rules
and regulations  promulgated  thereunder (the  "Securities  Laws").  As of their
respective dates, the Parent Reports (i) complied,  and any Parent Reports filed
with  the SEC  subsequent  to the date  hereof  will  comply,  as to form in all
material  respects with the applicable  requirements  of the Securities Laws and
(ii) did not, and any Parent  Reports filed with the SEC  subsequent to the date
hereof will not,  contain  any untrue  statement  of a material  fact or omit to
state a material  fact  required to be stated  therein or  necessary to make the
statements made therein, in the light of the circumstances under which they were
made,  not  misleading.  There  is  no  unresolved  violation  asserted  by  any
government authority with respect to any of the Parent Reports.

(b) Each of the balance sheets included in or incorporated by reference into the
Parent Reports  (including the related notes and schedules) fairly presented the
financial  position of the entity or entities to which it relates as of its date
and each of the statements of  operations,  stockholders'  equity  (deficit) and
cash flows  included in or  incorporated  by reference  into the Parent  Reports
(including  any related  notes and  schedules)  fairly  presented the results of
operations,  retained  earnings or cash flows, as the case may be, of the entity
or entities to which it relates for the periods set forth therein,  in each case
in  accordance  with United  States  generally  accepted  accounting  principles
("GAAP")  consistently  applied  during the periods  involved,  except as may be
noted  therein  and except,  in the case of the  unaudited  statements,  for the
absence of notes thereto,  and subject to normal recurring year-end  adjustments
which have not been and will not be material in nature or amount.

4.6. No Undisclosed Liabilities. Except as disclosed in the Parent Reports filed
prior to the date  hereof,  and  except  for  normal  or  recurring  liabilities
incurred since March 31, 2000 in the ordinary course of business consistent with
past practices, Parent and its subsidiaries do not have any liabilities,  either
accrued,  contingent  or  otherwise,  of the type  required to be  reflected  in
financial  statements in accordance with GAAP, and whether due or to become due,
which  individually  or in the aggregate,  have had or are reasonably  likely to
have  a  material  adverse  effect  on  the  properties,   business,  prospects,
operations,  earnings,  assets,  liabilities  or  the  condition  (financial  or
otherwise) (a "Material Adverse Effect") of Parent.

4.7.  Absence of Certain  Changes or Events.  Except as  disclosed in the Parent
Reports  filed with the SEC prior to the date  hereof or in  Section  4.7 of the
Disclosure  Schedule,  since December 31, 1999, Parent and its subsidiaries have
conducted their respective businesses only in the ordinary course, and there has
not been (a) any change, circumstance or event that could reasonably be expected
to result in a Material Adverse Effect on Parent, Newco, Sub or the transactions
contemplated by this Agreement, (b) any declaration, setting aside or payment of
any dividend or other  distribution  with respect to the Parent  Common Stock or
Investor  Interests,  (c)  any  material  commitment,   contractual  obligation,
borrowing,  capital  expenditure or transaction  (each, a "Commitment")  entered
into by  Parent  or any of its  subsidiaries  outside  the  ordinary  course  of
business,  or (d) any  material  change in the Parent's  accounting  principles,
practices or methods.

4.8. No Conflict. The execution and delivery by each of Parent and Newco of this
Agreement, and by Parent, Newco, Sub and Motient Communications of the Ancillary
Agreements  to which  it is a party,  and the  consummation  by each of  Parent,
Newco, Sub and Motient  Communications of the transactions  contemplated  hereby
and thereby and compliance  with the provisions  hereof and thereof  (including,
without limitation,  the issuance,  sale and delivery of the Investor Interests)
will not (a) violate or conflict with, or require any consent,  approval, notice
or filing  under,  any  provision of any domestic  (federal,  state or local) or
foreign law,  statute,  rule or  regulation,  or any ruling,  writ,  injunction,
order,  judgment  or  decree  of  any  court,  administrative  agency  or  other
governmental  body  applicable  to it, or any of its  properties or assets other
than  violations or conflicts  which would not  reasonably be expected to have a
Material Adverse Effect on Parent,  Newco, Sub or the transactions  contemplated
by this Agreement or the Ancillary  Agreements,  (b) conflict with, or result in
any violation or breach of, or constitute  (with due notice or lapse of time, or
both) a default or loss of a benefit under, or cause or permit the  acceleration
under,  the terms,  conditions or provisions of (i) the Series A and Series B 12
1/4% Senior Notes due 2008 Indenture,  dated March 31, 1998, of Motient Holdings
Inc.  ("Holdings")  (the  "Indenture")  or (ii) any other  indenture,  mortgage,
guaranty, lease, license or other contract, agreement or understanding,  written
or oral (each,  a  "Contract")  to which  Parent,  Newco or Sub is a party or to
which any of their  properties or assets are subject (all of which are listed in
Section 4.8 of the Disclosure  Schedule)  which could  reasonably be expected to
have a  Material  Adverse  Effect  on  Parent,  Newco,  Sub or the  transactions
contemplated by this Agreement,  or any of the Ancillary Agreements,  (c) result
in the creation or imposition of any Encumbrance  upon any of Parent's,  Newco's
or Sub's  properties  or assets  which  could  reasonably  be expected to have a
Material Adverse Effect on Parent,  Newco, Sub or the transactions  contemplated
by this Agreement or any of the Ancillary  Agreements,  or (d) violate Parent's,
Newco's or Sub's  organizational  documents.  Parent and Sub have  received  all
necessary  consents or waivers from their lenders and guarantors with respect to
the transactions contemplated hereby and by the Ancillary Agreements (other than
any consents that may be needed in connection with the transactions contemplated
by the Section 2.1 Letter), and the fairness opinion(s) required by Section 4.11
of the Indenture  has/have been obtained and copies of such  documents have been
delivered to the Investors.  No other  consent,  waiver,  approval,  document or
action is required for Parent and its subsidiaries (including Sub) to be in full
compliance  with the  provisions of the agreements  relating to their  financing
arrangements  upon consummation of the transactions  contemplated  hereby and by
the Ancillary Agreements.

4.9. Litigation;  Orders. Except as set forth in the Parent Reports, there is no
civil, criminal or administrative action, suit, claim, notice, hearing, inquiry,
proceeding  or  investigation  at law  or in  equity  by or  before  any  court,
arbitrator or similar panel,  governmental  instrumentality  or other agency now
pending or, to the best knowledge of Parent,  threatened  against Parent, Sub or
Newco or the assets  (including  the  Intellectual  Property) of Parent,  Sub or
Newco (a  "Litigation")  which if determined  adversely to Parent,  Sub or Newco
could reasonably be expected to have a Material Adverse Effect on Parent, Newco,
Sub or the transactions  contemplated by this Agreement.  None of Parent, Sub or
Newco is subject to any order,  writ,  injunction  or decree of any court of any
federal, state, municipal or other domestic or foreign governmental  department,
commission, board, bureau, agency or instrumentality.

4.10.  Compliance with Laws; Permits.  Except as provided in Section 4.10 of the
Disclosure  Schedule and except for matters  governed by Section  4.15,  Parent,
Newco and Sub are and have been, since their respective dates of  incorporation,
in compliance  with, and have conducted  their business in compliance  with, all
federal,  state,  local and foreign laws, rules,  ordinances,  codes,  consents,
authorizations,  registrations,  regulations, decrees, directives, judgments and
orders,  including  environmental,  applicable  to them other than  instances of
non-compliance  which  have not had and are not  reasonably  expected  to have a
Material Adverse Effect on Parent,  Newco, Sub or the transactions  contemplated
hereby. Each of Parent, Newco and Sub has all federal,  state, local and foreign
governmental licenses,  permits,  qualifications and authorizations  ("Permits")
materially necessary in the conduct of its business as currently conducted.  All
such Permits are in full force and effect, and no material  violations have been
recorded in respect of any such Permits;  no material  proceeding is pending or,
to the best knowledge of Parent,  threatened to revoke or limit any such Permit;
and no such Permit will be  suspended,  cancelled or  adversely  modified in any
material  respect as a result of the execution and delivery of this Agreement or
the Ancillary  Agreements and the consummation of the transactions  contemplated
hereby or thereby.

4.11.  Offering  Exemption.  Assuming  the accuracy of the  representations  and
warranties  contained  in Section 5 hereof,  the offer and sale of the  Investor
Interests as  contemplated  hereby,  and issuance and delivery of Parent  Common
Stock in  connection  with the Parent  Conversions  or upon the  exercise of the
Parent  Common  Stock  Purchase  Option (as defined  below) are each exempt from
registration under the Securities Act as in effect on the date of this Agreement
and under  applicable  state  securities  and "blue sky" laws,  as  currently in
effect.

4.12. Consents. No permit,  authorization,  consent or approval of or by, or any
notification of or filing with, any person (governmental or private) is required
by Parent or Newco in connection with the execution, delivery and performance of
this  Agreement,  or by Parent,  Newco or Sub in connection  with the execution,
delivery and performance of the Ancillary Agreements to which it is a party, the
consummation by Parent, Newco or Sub of the transactions  contemplated hereby or
thereby,  or the issuance,  sale or delivery of the Investor Interests or Parent
Common Stock (other than (i) such  notifications  or filings  required under the
HSR Act,  the  Communications  Act of 1934,  as  amended  (the  "FCC  Act")  and
applicable  federal or state  securities  laws, if any, which shall be made on a
timely basis and (ii) permits, authorizations,  consents and approvals which, if
not obtained, could not reasonably be expected to have a Material Adverse Effect
on Parent, Newco, Sub or the transactions contemplated by this Agreement and the
Ancillary Agreements).

4.13. Brokers. No agent,  broker,  investment banker or other firm or person, is
or will be entitled to any broker's or finder's fee or any other  commission  or
similar fee from Parent,  Sub or Newco in connection  with this Agreement or the
Ancillary Agreements or any of the transactions contemplated hereby or thereby.

4.14.  Public  Utility  Holding  Company,  Etc.  Neither Parent or Newco nor any
Subsidiary  is: (i) a "public  utility  company" or a "holding  company,"  or an
"affiliate" or a "subsidiary  company" of a "holding company," or an "affiliate"
of a "public utility company," a "holding company" or a "subsidiary  company" of
a holding  company as such  terms are  defined  in the  Public  Utility  Holding
Company Act of 1935, as amended,  or (ii) a "public  utility," as defined in the
Federal  Power  Act,  as  amended,  or  (iii)  an  "investment  company"  or  an
"affiliated  person" thereof or an "affiliated  person" of any such  "affiliated
person," as such terms are  defined in the  Investment  Company Act of 1940,  as
amended.

4.15.  FCC(a) . (a) Section 4.15 of the Disclosure  Schedule contains a true and
complete   list  of  all  material   licenses,   permits,   and   authorizations
("Licenses"),  including  the  frequencies  authorized  for and the issuance and
expiration  dates of each  such  License,  issued to Parent or Sub by the FCC in
connection  with the  operation  of the  Existing  Business.  No such License is
subject to any  restriction  or  condition  which  would  limit in any  material
respect the full  operation of the  Existing  Business as now  operated,  and no
proceeding, inquiry, investigation or other administrative action is pending or,
to Parent's knowledge,  threatened by or before the FCC that would reasonably be
expected  to result in the  revocation  of any  material  FCC  authorization  or
otherwise  impair in any  material  respect the full  operation  of the Existing
Business. The representations  contained in this Section 4.15 are limited by the
statements  set forth in the  section  of  Parent's  most  recent  SEC Form 10-K
entitled  "Business  --  Regulation"  filed  with the  Securities  and  Exchange
Commission on March 30, 2000 ("Regulatory Disclosure"). The statements contained
in the Regulatory Disclosure fully and accurately describe,  with respect to the
Existing Business,  the material legal matters and proceedings arising under the
Communications  Act of 1934, as amended,  and the published rules,  regulations,
and policies promulgated thereunder by the FCC.

(b) Section 4.15 of the Disclosure Schedule contains a true and complete list of
all  material  pending   applications,   including  requests  for  extension  of
construction or other performance milestones ("Applications"), and including the
frequencies applied for and the filing date of each such Application,  that have
been  filed by Parent or Sub with the FCC  relating  to the  Existing  Business.
Neither  Parent  nor Sub is aware of any reason  why any  Application  would not
granted by the FCC.  Parent and Sub have delivered to Investor true and complete
copies of the Licenses and Applications, including any all additions, amendments
and other modifications thereto.

(c) Sub is the authorized legal holder of all the Licenses.  The Licenses are in
good  standing,  are in full force and effect,  and are unimpaired by any act or
omission of Parent, Sub, or any of their officers,  directors, or employees; and
the operation of the Existing  Business is in full compliance with the Licenses.
These  Licenses  are  sufficient  for the  lawful  conduct of the  business  and
operation of the Existing Business in the manner and to the full extent they are
currently conducted.  All material reports, forms, and statements required to be
filed with the FCC with respect to the Existing Business have been filed and are
complete and accurate in all material respects.

(d) In  1999,  Sub  had  access  to the  spectrum  assigned  to Sub in the  1999
coordination  agreement  among  the  North  American  L-band  operators.  Parent
believes  that Sub  should  continue  to have  access in 2000 to as much of this
spectrum as Sub is able to use.

(e) No consent,  authorization,  approval,  order,  exemption,  waiver, or other
action of the FCC is required for the consummation of the Initial Investment.

4.16. Sub Representations and Warranties. All representation and warranties made
by Sub in or pursuant to the Research and  Development  Agreement  and the Asset
Sale  Agreement  (as  qualified  by  the  disclosure   schedule  thereto),   are
incorporated  herein  as  though  made  in  their  entirety  by  Parent  in this
Agreement.

4.17.  Restrictions.  Newco is not and will not be a party to any loan agreement
or  other  financing  document  giving  rise to any  obligations,  restrictions,
limitations  or  Encumbrances  with  respect to Newco or its assets.  So long as
Parent  shall own an interest in Newco of 50% or greater,  the only  contractual
obligations  of Parent  relating to Newco  (other than those  contained  in this
Agreement and the Ancillary Agreements) shall be the provisions of Parent's term
loan  agreement  and the  revolving  credit  facility  of  Holdings  relating to
Parent's  subsidiaries.  Following  consummation of the Investors Option Closing
and assuming that Parent shall then own less than a 50%  Percentage  Interest in
Newco,  such  requirements  shall cease to be  applicable,  other than  Parent's
pledge of all of its Membership Interests in Newco to its banks and guarantors.

4.18. Newco  Activities.  Newco has not conducted any business or engaged in any
activity  or taken any  actions,  other than those  solely in  connection  with,
relating to, and necessary for this  Agreement and the Ancillary  Agreements and
the consummation of the transactions  contemplated hereby or thereby.  Newco has
no assets,  other than a nominal  amount of cash  obtained  in  connection  with
Parent's subscription for its Newco Interests, and no liabilities or obligations
of any type whatsoever other than its obligations under the Ancillary Agreements
to which it is a party.

4.19.  Disclosure.  Neither this Agreement nor any Ancillary  Agreement (nor any
certificate  or  instrument  executed in connection  with this  Agreement or any
Ancillary  Agreement)  furnished  or made to the  Investors  by or on  behalf of
Parent,  Sub or Newco  omits to state a  material  fact  required  to be  stated
therein  or  necessary  in order to make the  statements  contained  herein  and
therein,  in  light  of the  circumstances  under  which  they  were  made,  not
misleading.

Section 5.  Representations  and  Warranties  of the  Investors.  Each  Investor
represents and warrants to Parent as of the date hereof as follows:

5.1.  Investment  Representations(a)  . (a) Such Investor  understands  that the
Investor  Interests,  and the Parent Common Stock Purchase Option and the Parent
Common  Stock  to  be  issued  pursuant  thereto   (collectively,   the  "Parent
Securities") (i) have not been, and will not be, registered under the Securities
Act or any state securities laws, (ii) are being offered and sold pursuant to an
exemption from registration contained in the Securities Act based in part on the
representations  of such  Investor  contained in this  Agreement,  and (iii) the
Parent  Securities may not be sold unless such  disposition is registered  under
the  Securities  Act and  applicable  state  securities  laws or is exempt  from
registration thereunder.

(b)  Acquisition  for  Own  Account.  Such  Investor  is  acquiring  the  Parent
Securities for its own account,  for investment  only and not with a view to the
distribution thereof within the meaning of the Securities Act.

(c) Accredited Investor; Domicile. Such Investor is an "Accredited Investor" (as
defined in Rule 501(a) under the Securities Act). Such Investor is a resident of
the  State or  Commonwealth  set  forth on  Schedule  I  hereto  and the  Parent
Securities  were  offered  and  sold to such  Investor  solely  in the  State or
Commonwealth set forth on Schedule I hereto.

(d)  Investors  Able  to Bear  Economic  Risk.  Such  Investor  has  substantial
experience in evaluating and investing in private  transactions of securities in
companies  similar to Newco and Parent so that it is capable of  evaluating  the
merits and risks of its  investment  in Newco and Parent and has the capacity to
protect its own interests.  Such Investor  understands that an investment in the
Parent Securities  acquired pursuant to this Agreement is highly speculative and
involves  substantial economic risk. Such Investor understands that it must bear
the economic risk of this investment  indefinitely  unless Parent Securities are
registered  pursuant to the Securities Act, or an exemption from registration is
available,  and that such  Investor  may  sustain,  and is  financially  able to
sustain,  a complete loss of its  investment  pursuant to this  Agreement.  Such
Investor  understands  that the Company has no present  intention of registering
the Parent Securities. Such Investor also understands that there is no assurance
that any exemption from registration  under the Securities Act will be available
and that,  even if  available,  such  exemption  may not allow such  Investor to
transfer all or any portion of Parent Securities under the circumstances, in the
amounts or at the times such Investor might propose.

(e) Investor Can Protect Its Interest.  By reason of its or of its  management's
business or financial experience,  such Investor has the capacity to protect its
own  interests  in  connection  with  the  transactions   contemplated  by  this
Agreement.   Further,   such  Investor  is  aware  of  no   publication  of  any
advertisement  in  connection  with  the   transactions   contemplated  by  this
Agreement.

(f) Company  Information.  Such Investor has had an  opportunity  to discuss the
business,  management and financial  affairs of Parent and Newco with directors,
officers  and  management  of Parent and Newco.  Such  Investor has also had the
opportunity to ask questions of, and receive answers from,  Parent and Newco and
its management regarding the terms and conditions of this Investment.

5.2. Organization and Good Standing;  Power and Authority.  Such Investor (i) is
duly  organized,  validly  existing and in good  standing  under the laws of its
jurisdiction  of  organization  and (ii) has all requisite  corporate  power and
authority to own,  lease and operate its properties and to carry on its business
as presently  conducted.  Such Investor has all requisite power and authority to
enter into and carry out the transactions contemplated by this Agreement and the
Ancillary Agreements to which it is a party.

5.3. Authorization of Documents. The execution,  delivery and performance by the
Investor of this Agreement and each of the Ancillary Agreements to which it is a
party and the consummation of the transactions  contemplated  hereby and thereby
have been duly authorized by all requisite  corporate action on the part of such
Investor, and this Agreement and each of such Ancillary Agreements when executed
will  constitute  a  legal,  valid  and  binding  obligation  of such  Investor,
enforceable  against such Investor in accordance  with its terms,  except to the
extent that  enforceability  may be limited by  bankruptcy,  insolvency or other
similar laws affecting creditors' rights generally and except to the extent that
the remedy of specific  performance  and injunction and other forms of equitable
relief may be subject to equitable defenses.

5.4. No Conflict.  The execution and delivery by such Investor of this Agreement
and the Ancillary  Agreements to which it is a party,  and the  consummation  by
such Investor of the transactions contemplated hereby and thereby and compliance
with the provisions hereof and thereof will not (a) violate or conflict with, or
require any consent,  approval,  notice or filing  under,  any  provision of any
domestic (federal,  state or local) or foreign law, statute, rule or regulation,
or any  ruling,  writ,  injunction,  order,  judgment  or decree  of any  court,
administrative agency or other governmental body applicable to it, or any of its
properties  or assets,  (b) conflict  with, or result in any violation or breach
of, or constitute  (with due notice or lapse of time, or both) a default or loss
of a benefit  under,  or cause or permit  the  acceleration  under,  the  terms,
conditions or provisions of any indenture, mortgage, guaranty, lease, license or
other  contract,  agreement or  understanding,  written or oral to which it is a
party or to which its properties or assets is subject, which could reasonably be
expected  to have a  Material  Adverse  Effect  on such  Investor's  ability  to
consummate the  transactions  contemplated  by the Agreement,  (c) result in the
creation or imposition of any Encumbrance  upon any of its properties or assets,
which could  reasonably  be expected to have a Material  Adverse  Effect on such
Investor's ability to consummate the transactions contemplated by this Agreement
or (d) violate its organizational documents.

5.5. Litigation;  Orders. There is no civil, criminal or administrative  action,
suit, claim, notice, hearing, inquiry,  proceeding or investigation at law or in
equity by or  before  any  court,  arbitrator  or  similar  panel,  governmental
instrumentality  or other  agency now pending or, to the best  knowledge of such
Investor, threatened against such Investor which if determined adversely to such
Investor could  reasonably be expected to have a Material Adverse Effect on such
Investor's   ability  to  consummate  the  transactions   contemplated  by  this
Agreement. Such Investor is not subject to any order, writ, injunction or decree
of any court of any  federal,  state,  municipal  or other  domestic  or foreign
governmental department, commission, board, bureau, agency or instrumentality.

5.6.  Compliance with Laws;  Permits.  Such Investor is and has been,  since the
date of its incorporation, in compliance with, and has conducted its business in
compliance with, all federal, state, local and foreign laws, rules,  ordinances,
codes,   consents,   authorizations,    registrations,   regulations,   decrees,
directives,  judgments and orders  applicable to it, which if Investor failed to
comply  would be  reasonably  likely to have a Material  Adverse  Effect on such
Investor's   ability  to  consummate  the  transactions   contemplated  by  this
Agreement.  Such Investor has all Permits materially necessary in the conduct of
its  business as  currently  conducted.  All such  Permits are in full force and
effect,  and no material  violations  have been  recorded in respect of any such
Permits;  no material  proceeding  is pending or, to the best  knowledge  of the
Investor, threatened to revoke or limit any such Permit; and no such Permit will
be suspended,  cancelled or adversely  modified as a result of the execution and
delivery of this Agreement or the Ancillary  Agreements and the  consummation of
the transactions contemplated hereby or thereby.

5.7. Consents.  No permit,  authorization,  consent or approval of or by, or any
notification of or filing with, any person (governmental or private) is required
by such Investor in connection  with the execution,  delivery and performance of
this Agreement, or in connection with the execution, delivery and performance of
the Ancillary  Agreements to which it is a party,  or the  consummation  by such
Investor  of the  transactions  contemplated  hereby or thereby  (other than (i)
notifications  or filings required under the HSR Act, the FCC Act and applicable
federal or state  securities  law, if any, which shall be made on a timely basis
and (ii) permits, authorizations, consents and approvals which, if not obtained,
could not  reasonably  be  expected  to have a Material  Adverse  Effect on such
Investor's   ability  to  consummate  the  transactions   contemplated  by  this
Agreement).

5.8. Brokers. No agent, broker, investment banker or other firm or person, is or
will be entitled to any  broker's or  finder's  fee or any other  commission  or
similar fee from such Investor in connection  with this  Agreement or any of the
transactions contemplated hereby.

5.9.  Appointment of Investor Group  Designees.  Without in any way limiting any
Investor's  right  to  vote  or  transfer  its  Investor  Interest  in its  sole
discretion  or to  otherwise  exercise  its rights or receive  the  benefits  of
ownership of such Investor Interest  (subject,  in each case to the limitations,
restrictions  and other  provisions  contained in the LLC Operating  Agreement),
each Investor hereby  irrevocably  delegates the power and authority relating to
the exercise of the Parent Conversions, and the matters set forth in clauses (i)
through (iv) below, to such  Investor's  Investor Group Designee as set forth on
Schedule I hereto  (each,  an  "Investor  Group  Designee")  and  appoints  such
Investor  Group  Designee as its true and lawful agent and attorney,  for and in
the name, place and stead of such Investor (i) to exercise at any time the right
to deliver a Conversion Notice,  (ii) to request a Parent  Conversion,  (iii) to
exercise such Investor's  rights under Section 3.1 of this Agreement and (iv) to
send or receive  notices,  and make  elections and decisions of any type,  under
this  Agreement.  Each  Investor  hereby  affirms  that this  grant of power and
authority may under no  circumstances  be revoked  except with the prior written
consent of such Investor's  Investor Group Designee and Parent,  which shall not
be  unreasonably  withheld.  The authority  given to any Investor Group Designee
hereunder  may be  transferred  by such  Investor  Group  Designee to any single
person or entity upon notice to Parent, but in no event shall these be more than
three Investor Group Designees.

Section  6.  Representations  and  Warranties  of Parent  and  Newco.  Except as
disclosed in the disclosure  schedule to be delivered by Parent and Newco to the
Investors  on the  Newco  Update  Date (the  "Newco  Disclosure  Schedule"),  as
required by Sections  2.2(d) and 2.3(a),  Parent and Newco shall  represent  and
warrant to the  Investors  on the Newco  Update  Date and the  Investors  Option
Closing Date as follows:

6.1. Organization and Good Standing; Power and Authority;  Qualifications. Newco
(a) is duly organized,  validly  existing and in good standing under the laws of
its  jurisdiction of organization  and (b) has all requisite  limited  liability
company  power and  authority to own,  lease and operate its  properties  and to
carry on its business as presently conducted.  Newco has all requisite power and
authority  to enter  into and carry out the  transactions  contemplated  by this
Agreement  and the  Ancillary  Agreements  to  which  it is a  party.  Newco  is
qualified to transact business as a foreign limited liability company in, and is
in good standing under the laws of the Commonwealth of Virginia.

6.2. Authorization of the Documents. The execution,  delivery and performance by
Newco of this  Agreement and each of the  Ancillary  Agreements to which it is a
party, and the consummation of the transactions  contemplated hereby and thereby
have been duly authorized by all requisite  limited  liability company action on
the part of Newco (and do not or will not require the approval or consent of the
shareholders of Newco), and this Agreement and each of the Ancillary  Agreements
when executed will  constitute a legal,  valid and binding  obligation of Newco,
enforceable against Newco in accordance with its terms except to the extent that
enforceability  may be limited by  bankruptcy,  insolvency or other similar laws
affecting  creditors'  rights generally and except to the extent that the remedy
of specific  performance and injunction and other forms of equitable  relief may
be subject to equitable defenses.

6.3.  Capitalization.  Immediately  prior to the Investors  Option Closing,  the
ownership  of Newco shall be as then set forth in the LLC  Operating  Agreement.
All such  outstanding  interests will be validly issued.  Except pursuant to the
LLC Operating  Agreement,  no member of Newco is entitled to pre-emptive rights.
Except for the Investors Option granted to the Investors pursuant to Section 2.1
of this  Agreement,  there will not as of the  Investors  Option  Closing be any
outstanding Newco Options. Newco has not, since its inception,  declared or paid
any dividend or made any other  distribution of cash, stock or other property to
its members.

6.4.  Authorization  and  Issuance of  Investor  Interests.  The  authorization,
reservation,  issuance,  sale and delivery of the Investor Interests pursuant to
the  Investors  Option  have  been  duly  authorized  by all  requisite  limited
liability  company  action  on the  part of  Newco  and  when  issued,  sold and
delivered in accordance  with this  Agreement,  the Investor  Interests  will be
validly  issued and  outstanding,  with no personal  liability  attaching to the
ownership  thereof  (other than as provided in the  Delaware  Limited  Liability
Act),  free and clear of any  Encumbrances,  other  than  Encumbrances,  if any,
arising as a result of actions  taken by the  Investors  or arising  pursuant to
applicable  federal and state  securities laws, and not subject to preemptive or
similar rights of members of Newco or others. The terms,  designations,  powers,
preferences  and  relative,   optional  and  other  special   rights,   and  the
qualifications,  limitations and restrictions,  of the Investor Interests are as
stated in the LLC Operating Agreement.

6.5.  Financial  Statements.  Each of the  balance  sheets  included in the most
recent monthly and quarterly Newco  Financial  Statements (as defined in Section
7.8(b))  fairly  presented the  financial  position of the entity or entities to
which  it  relates  as of its date and  each of the  statements  of  operations,
stockholders'  equity  (deficit)  and cash  flows  included  in the most  recent
monthly and quarterly Newco Financial Statements fairly presented the results of
operations,  retained  earnings or cash flows, as the case may be, of the entity
or entities to which it relates for the periods set forth therein,  in each case
in accordance with GAAP consistently applied during the periods involved, except
as may be noted therein and except for the absence of notes thereto, and subject
to normal  recurring  year-end  adjustments  which have not been and will not be
material in nature or amount.

6.6. No  Undisclosed  Liabilities.  Except as disclosed  in the Newco  Financial
Statements,  and except for normal or recurring  liabilities  incurred since the
date of the Newco  Financial  Statements  in the  ordinary  course  of  business
consistent  with past  practices,  Newco does not have any  liabilities,  either
accrued,  contingent  or  otherwise,  of the type  required to be  reflected  in
financial  statements in accordance with GAAP, and whether due or to become due,
which  individually  or in the aggregate,  have had or are reasonably  likely to
have a Material Adverse Effect on Newco.

6.7.  Absence of Certain  Changes or Events.  Except as  disclosed  in the Newco
Financial Statements,  since the date of the Newco Financial  Statements,  Newco
has conducted its business only in the ordinary  course,  and there has not been
(a) any  change,  circumstance  or event that could  reasonably  be  expected to
result in a Material Adverse Effect on Newco, (b) any declaration, setting aside
or payment of any  dividend or other  distribution  with respect to the Investor
Interests,  (c) any  material  Commitment  entered  into by  Newco  outside  the
ordinary course of business,  or (d) any material  change in Newco's  accounting
principles, practices or methods.

6.8. No Conflict. The execution and delivery by Newco of this Agreement,  and by
Newco of the Ancillary  Agreements to which it is a party,  and the consummation
by Newco of the transactions contemplated hereby and thereby and compliance with
the  provisions  hereof and thereof  will not (a) violate or conflict  with,  or
require any consent,  approval,  notice or filing  under,  any  provision of any
domestic (federal,  state or local) or foreign law, statute, rule or regulation,
or any  ruling,  writ,  injunction,  order,  judgment  or decree  of any  court,
administrative agency or other governmental body applicable to it, or any of its
properties  or  assets  other  than  violations  or  conflicts  which  would not
reasonably be expected to have a Material  Adverse Effect on Newco, (b) conflict
with, or result in any violation or breach of, or constitute (with due notice or
lapse of time, or both) a default or loss of a benefit under, or cause or permit
the acceleration under, the terms, conditions or provisions of (i) the Indenture
or (ii) any  Contract  to which Newco is a party or to which its  properties  or
assets is subject  (all of which are listed in Section  6.8(b)(ii)  of the Newco
Disclosure  Schedule)  which  could  reasonably  be  expected to have a Material
Adverse  Effect on  Newco,  (c)  result in the  creation  or  imposition  of any
Encumbrance  upon any of Newco's  properties or assets which could reasonably be
expected to have a Material  Adverse  Effect on Newco,  or (d)  violate  Newco's
organizational documents.

6.9.  Litigation;  Orders.  There  is  no  Litigation  against  Newco  which  if
determined  adversely to Newco could  reasonably  be expected to have a Material
Adverse Effect on Newco. Newco is not subject to any order, writ,  injunction or
decree  of any court of any  federal,  state,  municipal  or other  domestic  or
foreign  governmental   department,   commission,   board,  bureau,   agency  or
instrumentality.

6.10.  Compliance with Laws;  Permits.  Newco is and has been, since its date of
incorporation,  in compliance with, and has conducted its business in compliance
with, all federal,  state,  local and foreign laws,  rules,  ordinances,  codes,
consents,  authorizations,   registrations,  regulations,  decrees,  directives,
judgments and orders, including  environmental,  applicable to it which if Newco
failed to comply could  reasonably be expected to have a Material Adverse Effect
on Newco.  Newco has all  Permits  materially  necessary  in the  conduct of its
business as currently conducted.  All such Permits are in full force and effect,
and no material violations have been recorded in respect of any such Permits; no
material proceeding is pending or, to the best knowledge of Newco, threatened to
revoke or limit any such Permit; and no such Permit will be suspended, cancelled
or adversely  modified in any material  respect as a result of the execution and
delivery of this Agreement or the Ancillary  Agreements and the  consummation of
the transactions contemplated hereby or thereby.

6.11.  Title.  Newco  has  good  and  marketable  title  to all of its  material
properties  and  assets,  real  and  personal,  and has  good  title  to all its
leasehold  interests,  in each case subject only to Encumbrances  created in the
ordinary course of business.

6.12.  ERISA Matters.  Each plan  maintained by or contributed to by Newco is in
compliance  in all respects  with all  presently  applicable  provisions of law,
including,  without  limitation,  the Employee Retirement Income Security Act of
1974,  as amended,  including  the  regulations  and  published  interpretations
thereunder  ("ERISA");  neither  Newco nor any entity that is or was at any time
treated as a single employer with Newco under Section 414(b), (c), (m) or (o) of
the Internal  Revenue Code of 1986, as amended,  including the  regulations  and
published  interpretations  thereunder  (the  "Code") has incurred or expects to
incur  liability  with respect to a plan subject to Title IV of ERISA or Section
412 of the Code;  and each "pension  plan" (as defined in ERISA) for which Newco
would have any liability  that is intended to be qualified  under Section 401(a)
of the Code is so qualified in all material  respects and nothing has  occurred,
whether  by action or by  failure  to act,  which  would  cause the loss of such
qualification.

6.13.  Insurance.  Newco  maintains  property and casualty,  general  liability,
personal injury,  director and officer and other similar types of insurance with
financially  sound and reputable  insurers that is adequate and consistent  with
industry standards.  Newco has not received notice from, and has no knowledge of
any threat by, any insurer (that has issued any insurance  policy to Newco) that
such insurer intends to deny coverage under or cancel,  discontinue or not renew
any insurance policy covering Newco presently in force.

6.14. Labor Relations;  Employees. Newco is not delinquent in payments to any of
its employees,  for any wages,  salaries,  commissions,  bonuses or other direct
compensation  for any services  performed by the date hereof or amounts required
to be  reimbursed by them to the date hereof,  (ii) Newco is in compliance  with
all applicable federal,  state and local laws, rules and regulations  respecting
employment,  employment practices, labor, terms and conditions of employment and
wages and hours except where failure to comply would not, individually or in the
aggregate,  have a Material Adverse Effect on Newco, (iii) Newco is not bound by
or subject to (and none of its assets or  properties  is bound by or subject to)
any written or oral,  express or implied,  commitment  or  arrangement  with any
labor  union,  and no labor union has  requested  or, to the best  knowledge  of
Newco, has sought to represent any of the employees,  representatives  or agents
of Newco, (iv) there is no labor strike, dispute,  slowdown or stoppage actually
pending,  or, to the best  knowledge of Newco,  threatened  against or involving
Newco,  and (v) to the best knowledge of Newco, no salaried key employee has any
plans to  terminate  his or her  employment  with Newco.  Each of the  executive
officers of Newco who has or had access to confidential information of Newco has
executed a confidentiality  agreement, and such agreements are in full force and
effect.

6.15.  Agreements(a)  . (a) Newco is not a party to, or bound or subject to, any
Contract,  other than (x) any  Contract  which (i)  pursuant  to its terms,  has
expired,  been terminated or fully  performed by the parties,  and in each case,
under which Newco has no liability,  contingent  or otherwise,  or (ii) involves
monthly  payments  to or from Newco (as  opposed to an  indemnity  agreement  or
similar  contract  under  which a party is not  required  to make fixed  monthly
payments) which monthly payments do not aggregate on an annual basis to $250,000
or more, and in each case, is not material to the business, condition (financial
or otherwise),  operations or prospects of Newco and (y) as set forth in Section
4.17.

(b) Assuming the due execution and delivery by the other parties  thereto,  each
of such Contracts is, as of the date hereof,  legal, valid,  binding and in full
force and effect  and  enforceable  in  accordance  with its terms.  There is no
breach,  violation or default by Newco (or, to the best knowledge of Newco,  any
other party)  under any such  Contract  except  where such breach,  violation or
default would not,  individually  or in the aggregate,  have a Material  Adverse
Effect on Newco, and no event (including,  without limitation,  the consummation
of the transactions  contemplated by this Agreement) which, with notice or lapse
of time or both,  would (A)  constitute a breach,  violation or default by Newco
(or, to the best  knowledge of Newco,  any other party) under any such  Contract
except where such breach, violation or default would not, individually or in the
aggregate, have a Material Adverse Effect on Newco, or (B) give rise to any lien
or right of termination,  modification,  cancellation,  prepayment,  suspension,
limitation,  revocation or  acceleration  against Newco under any such Contract.
Newco is not or,  to the  knowledge  of  Newco,  no  other  party to any of such
Contracts (i) is in arrears in respect of the performance or satisfaction of the
terms and conditions on its part to be performed or satisfied  under any of such
Contracts or (ii) has granted or has been granted any waiver or indulgence under
any of such Contracts or has repudiated any provision thereof.

6.16.  Offering  Exemption.  Assuming  the accuracy of the  representations  and
warranties  contained in Section 5 hereof, the issuance and delivery of Investor
Interests to the Investors upon exercise of the Investors Option are exempt from
registration under the Securities Act as in effect on the date of this Agreement
and under  applicable  state  securities  and "blue sky" laws,  as  currently in
effect.

6.17. Consents. No permit,  authorization,  consent or approval of or by, or any
notification of or filing with, any person (governmental or private) is required
by Newco in connection  with the  execution,  delivery and  performance  of this
Agreement,  or  by  Newco  in  connection  with  the  execution,   delivery  and
performance of the Ancillary Agreements to which it is a party, the consummation
by Newco of the transactions  contemplated  hereby or thereby,  or the issuance,
sale or delivery of the Investor Interests (other than (i) such notifications or
filings required under the HSR Act, the FCC Act and applicable  federal or state
securities laws, if any, which shall be made on a timely basis and (ii) permits,
authorizations,  consents  and  approvals  which,  if not  obtained,  could  not
reasonably be expected to have a Material Adverse Effect on Newco).

6.18. Brokers. No agent,  broker,  investment banker or other firm or person, is
or will be entitled to any broker's or finder's fee or any other  commission  or
similar  fee from  Newco in  connection  with this  Agreement  or the  Ancillary
Agreements or any of the transactions contemplated hereby or thereby.

6.19. Public Utility Holding Company,  Etc. Neither Newco nor any Subsidiary is:
(i) a "public  utility  company" or a "holding  company," or an "affiliate" or a
"subsidiary  company" of a "holding  company," or an  "affiliate"  of a " public
utility  company," a "holding  company" or a  "subsidiary  company" of a holding
company as such terms are defined in the Public Utility  Holding  Company Act of
1935,  as amended,  or (ii) a "public  utility," as defined in the Federal Power
Act, as amended,  or (iii) an  "investment  company" or an  "affiliated  person"
thereof or an "affiliated person" of any such "affiliated person," as such terms
are defined in the Investment Company Act of 1940, as amended.

6.20. FCC(a) . (a) Section 6.20 of the Newco Disclosure Schedule contains a true
and complete list of all material Licenses, including the frequencies authorized
for and the issuance and expiration dates of each such License, issued to Parent
or Sub or Newco by the FCC in  connection  with the  operation  of the  Existing
Business. No such License is subject to any restriction or condition which would
limit in any material respect the full operation of the Existing Business as now
operated,  and no proceeding,  inquiry,  investigation  or other  administrative
action is pending or, to  Parent's  knowledge,  threatened  by or before the FCC
that would  reasonably  be expected to result in the  revocation of any material
FCC authorization or otherwise impair in any material respect the full operation
of the Existing Business. The representations contained in this Section 6.20 are
limited by the  statements  set forth in the  section of  Parent's  most  recent
Regulatory  Disclosure.  The statements  contained in the Regulatory  Disclosure
fully and  accurately  describe,  with  respect to the  Existing  Business,  the
material legal matters and proceedings  arising under the  Communications Act of
1934, as amended, and the published rules, regulations, and policies promulgated
thereunder by the FCC.

(b) Section 6.20 of the Newco Disclosure  Schedule  contains a true and complete
list of all material Applications, and including the frequencies applied for and
the filing date of each such Application,  that have been filed by Parent or Sub
with the FCC relating to the Existing Business. Neither Parent nor Sub nor Newco
is aware of any reason why any Application would not granted by the FCC. Parent,
Sub and  Newco  have  delivered  to  Investor  true and  complete  copies of the
Licenses  and  Applications,  including  any  additions,  amendments  and  other
modifications thereto.

(c) Sub is the authorized legal holder of all the Licenses,  other than Licenses
held by Newco. The Licenses are in good standing, are full force and effect, and
are unimpaired by any act or omission of Parent,  Sub or Newco,  or any of their
officers, directors, or employees; and the operation of the Existing Business is
in full  compliance  with the Licenses.  These  Licenses are  sufficient for the
lawful  conduct of the  business and  operation of the Existing  Business in the
manner  and to the  full  extent  they are  currently  conducted.  All  material
reports, forms, and statements required to be filed with the FCC with respect to
the  Existing  Business  have been filed and are  complete  and  accurate in all
material respects.

(d) In  1999,  Sub  had  access  to the  spectrum  assigned  to Sub in the  1999
coordination  agreement  among  the  North  American  L-band  operators.  Parent
believes  that Sub  should  continue  to have  access  for the year in which the
Investors  Option  Closing  occurs to as much of this spectrum as Sub is able to
use.

(e) No consent,  authorization,  approval,  order,  exemption,  waiver, or other
action of the FCC is required for the consummation of the Initial Investment.

6.21.  Restrictions.  Newco is not and will not be a party to any loan agreement
or  other  financing  document  giving  rise to any  obligations,  restrictions,
limitations  or  Encumbrances  with  respect to Newco or its assets.  So long as
Parent  shall own an interest in Newco of 50% or greater,  the only  contractual
obligations  of Parent  relating to Newco  (other than those  contained  in this
Agreement and the Ancillary Agreements) shall be the provisions of Parent's term
loan  agreement  and the  revolving  credit  facility  of  Holdings  relating to
Parent's  subsidiaries.  Following  consummation of the Investors Option Closing
and assuming that Parent shall then own less than a 50%  Percentage  Interest in
Newco,  such  requirements  shall cease to be  applicable,  other than  Parent's
pledge of all of its Membership Interests in Newco to its banks and guarantors.

6.22. Sub  Representations  and Warranties.  All  representations and warranties
made by Sub in the Asset Sale Agreement (as qualified by the disclosure schedule
thereto),  are incorporated  herein as though made in their entirety by Newco in
this Agreement.

6.23.  Environmental  Matters.  There are,  with  respect  to Newco,  no past or
present  violations of  Environmental  Law (as defined below),  nor any actions,
activities,   circumstances,   conditions,  events,  incidents,  or  contractual
obligations  which are  reasonably  likely to give rise to any  liability  which
would have a Material Adverse Effect on Newco pursuant to any Environmental Law,
and neither Parent nor Newco has received any written notice with respect to any
of the  foregoing nor is any  Litigation  pending or, to the knowledge of Parent
and Newco, threatened in connection with any of the foregoing.

          For purposes of this Section 6.23, capitalized terms used herein shall
have the following meanings:

          "Environmental Laws" shall mean, all applicable provisions of federal,
state, local or foreign law (including applicable principles of common and civil
law),  statutes,   ordinances,  rules,  regulations,   published  standards  and
directives that have the force and effect of law, permits, licenses,  judgments,
writs,  injunctions,  decrees and orders  enacted,  promulgated or issued by any
Public   Authority,   and  all  indemnity   agreements  and  other   contractual
obligations,  as in effect at such date,  relating to (i) the  protection of the
environment,  including the air, surface and subsurface  soils,  surface waters,
groundwaters and natural resources,  and (ii) occupational health and safety and
exposure of persons to Hazardous Materials. Environmental Laws shall include the
Comprehensive Environmental Response,  Compensation and Liability Act, 42 U.S.C.
Sections 9601 et seq.,  and any other laws imposing or creating  liability  with
respect to Hazardous Materials.

          "Hazardous  Material"  shall  mean  any  substance  regulated  by  any
Environmental Law.

          "Public Authority" shall mean any supranational,  national,  regional,
state or local government court, governmental agency, authority,  board, bureau,
instrumentality or regulatory body.

6.24.  Proprietary Rights. Except for matters which would not, in the aggregate,
have a Material Adverse Effect on Newco,  (i) Newco is the sole owner,  free and
clear of any Encumbrance, of, or has a valid license, without the payment of any
royalty  except  with  respect  to  off-the-shelf   software  and  otherwise  on
commercially  reasonable  terms,  to, all U.S. and foreign  trademarks,  service
marks, logos,  designs,  trade names, internet domain names and corporate names,
and the goodwill of the business  connected  therewith and  symbolized  thereby,
patents,  registered  designs,  copyrights,  computer  software  and  databases,
whether or not  registered,  web sites and web pages and related  items (and all
intellectual property and proprietary rights incorporated therein) and all other
trade secrets,  research and development,  formulae,  know-how,  proprietary and
intellectual   property   rights  and   information,   including   all   grants,
registrations and applications relating thereto (collectively,  the "Proprietary
Rights")  described in Schedule  6.24 of the Newco  Disclosure  Schedule,  (such
Proprietary  Rights  owned by or  licensed  to Newco,  collectively,  the "Newco
Rights");  (ii) Newco has taken,  and will take, all actions which are necessary
or advisable in order to protect the Newco  Rights,  and to acquire  Proprietary
Rights,  consistent with prudent commercial practices in the  telecommunications
industry;  (iii) Newco's  rights in the Newco Rights are valid and  enforceable;
(iv) neither Parent nor Newco has received any demand,  claim, notice or inquiry
from any  person or entity in  respect  of the Newco  Rights  which  challenges,
threatens  to  challenge  or  inquires  as to  whether  there  is any  basis  to
challenge,  the validity  of, or the rights of Newco in, any such Newco  Rights,
and  neither  Parent nor Newco  knows of any basis for any such  challenge;  (v)
Newco is not in violation or infringement of, and has not violated or infringed,
any Proprietary  Rights of any other person or entity;  (vi) to the knowledge of
Parent and Newco, no person or entity is infringing any Newco Rights;  and (vii)
except on an  arm's-length  basis for  value and other  commercially  reasonable
terms, Newco has not granted any license with respect to any Newco Rights to any
person or entity.

6.25.  Disclosure.  Neither this Agreement nor any Ancillary  Agreement (nor any
certificate  or  instrument  executed in connection  with this  Agreement or any
Ancillary  Agreement) furnished or made to the Investor by or on behalf of Newco
omits to state a material  fact  required to be stated  therein or  necessary in
order to make the  statements  contained  herein  and  therein,  in light of the
circumstances under which they were made, not misleading.

Section 7. Certain Covenants.
           -----------------

7.1. Notification of Certain Matters. The Investors, Parent and Newco shall each
notify  the other  party in writing of its  discovery  of any matter  that would
render any of such  party's  representations  and  warranties  contained  herein
untrue or incorrect in any material respect.

7.2. Hart Scott-Rodino Filing. The parties shall make any appropriate filings of
Notification  and  Report  Forms  pursuant  to the HSR Act with  respect  to the
transactions  contemplated  hereby as  promptly  as  practicable  and  supply as
promptly as practicable any additional information and documentary material that
may be requested  pursuant to the HSR Act and take all other actions  reasonably
necessary to cause the  expiration  or  termination  of the  applicable  waiting
periods under the HSR Act as soon as practicable.

7.3. Affirmative Covenants.
     ---------------------

(a) System of Accounting. The books of account and other financial and corporate
records of Newco  shall be  maintained  in  accordance  with good  business  and
accounting  practices  to allow  the  preparation  of  financial  statements  in
accordance with generally accepted accounting principles.

(b) Maintenance of Existence,  etc. Newco shall, and (until the Investors Option
Closing)  Parent shall cause Newco and Sub to, maintain in full force and effect
its  respective  corporate  or  limited  liability  company  existence,  rights,
governmental  approvals and  franchises and all licenses and other rights to use
patents, processes,  trademarks, trade names or copyrights owned or possessed by
it and material to the conduct of its business.

(c) Compliance with Laws.  Newco shall, and (until the Investors Option Closing)
Parent shall cause Newco and Sub to,  comply with all  applicable  laws,  rules,
regulations and orders.

(d) Maintenance of Properties and Leases.  Newco shall, and (until the Investors
Option  Closing)  Parent shall cause Newco and Sub to, keep their  properties in
good repair, working order and condition, reasonable wear and tear excepted, and
from time to time make all reasonably  needful and proper,  or legally required,
repairs, renewals, replacements, additions and improvements thereto.

(e) Insurance.  Newco shall,  and (until the Investors  Option  Closing)  Parent
shall  cause  Newco  and Sub to,  keep its  respective  assets  which  are of an
insurable character, if any, insured by financially sound and reputable insurers
against loss or damage by fire,  extended  coverage and other  hazards and risks
and liability to persons and property to the extent and in the manner  customary
for companies in similar businesses similarly situated.  Newco shall, and (until
the  Investors  Option  Closing)  Parent  shall  cause Newco to, also obtain and
maintain  directors  and  officers  insurance  to the  extent  and in the manner
customary for companies similarly situated.

7.4. Certain Additional Covenants(a) . (a) Parent shall cause Sub and (until the
Investors  Option  Closing)  Newco  to  promptly  perform,   and  Parent  hereby
unconditionally  guarantees  the prompt  performance  by Newco and Sub of, their
respective  obligations  under  this  Agreement  and the  Ancillary  Agreements,
including,  without  limitation,  the  obligations  of  Sub  to  consummate  the
transactions contemplated by the Ancillary Agreements.

(b)  Until  the  later of (x) the  lapse  of the  Investors  Option,  or (y) the
Investors  Option  Closing,  Parent  shall not,  and shall not permit any of its
direct or indirect  subsidiaries to, engage in any transaction  which would have
the effect of transferring  ultimate  control of Sub to any person or entity not
controlled by Parent, or of divesting Parent of ultimate control of Sub, without
the consent of a majority in interest of the Investors,  which consent shall not
be unreasonably  withheld if (i) in connection  with a bona fide  disposition of
assets in which the stock or assets of Sub constitute  less than 50% in terms of
value,  ultimate control of Sub is transferred to a person or entity which shall
have  agreed in  writing  to be bound by the  provisions  hereof  applicable  to
Parent, (ii) such transaction shall not materially  interfere with or impede the
consummation  of the  transactions  contemplated  by this  Agreement  and/or the
Ancillary  Agreements,  and (iii) Parent shall expressly  acknowledge in writing
that it shall remain fully liable in respect of all  liabilities and obligations
(including indemnity obligations)  undertaken by it under this Agreement and the
Ancillary  Agreements even if such liabilities or obligations arise from actions
taken (or not taken) by such transferee.

(c)  Parent  shall,  and  shall  cause  Newco and Sub to,  use all  commercially
reasonable efforts to satisfy at the appropriate times all closing conditions to
the  consummation of the Initial  Closing,  the Investors  Option  Closing,  the
Parent Conversions, the Parent Common Stock Purchase Option and the transactions
contemplated  by  the  Ancillary  Agreements  (as  defined  in  the  Asset  Sale
Agreement).

(d) Parent shall not, and shall not permit Newco or Sub to,  become bound by any
contract,  undertaking or obligation that would prohibit,  restrict, require any
consent  for, or give rise to any  obligation  as a result of, the  transactions
contemplated   hereby  or  the   Ancillary   Agreements,   other  than  standard
anti-assignability  clauses in ordinary  course  agreements,  provided  that the
inability to transfer such agreements to Newco would not have a Material Adverse
Effect on Newco.

(e) Investment Company Act. Parent will not become an "investment company" or an
"affiliated  person" thereof or an "affiliated  person" of any such  "affiliated
person," as such terms are  defined in the  Investment  Company Act of 1940,  as
amended.

7.5.  Transactions  with  Affiliates.  Except  as  set  forth  herein  or in the
Ancillary  Agreements,  Newco  will not  engage in any  transaction  or group of
related transactions (including,  without limitation,  the purchase, lease, sale
or exchange of  properties of any kind or the rendering of any service) with any
affiliate,  except  in the  ordinary  course of  business  and  pursuant  to the
reasonable  requirements of Newco's  business and upon fair and reasonable terms
no less favorable to Newco than would be obtainable in a comparable arm's-length
transaction with a person not an affiliate. As used herein, the term "affiliate"
shall mean any  officer,  director,  10% or greater  stockholder,  or any family
member of any such person, or any business entity controlled by any such person;
without  limiting  the  generality  of the  foregoing,  Parent  and  each of its
subsidiaries and affiliates shall be deemed to be affiliates of Newco.

7.6.  Reservation  of Common  Stock.  From and after the Initial  Closing  Date,
Parent  shall at all times  reserve  and keep  available  out of its  authorized
shares of common  stock,  solely for the purpose of issue or  delivery  upon the
consummation of the Parent Merger and/or the exercise of the Parent Common Stock
Purchase Option, the maximum number of shares of Parent Common Stock that may be
issuable or  deliverable in connection  therewith.  Such shares of Parent Common
Stock are or will be duly authorized and, when issued or delivered in accordance
with its charter and against payment  therefor,  shall be validly issued,  fully
paid and non-assessable.

7.7. Use of Proceeds.  The amount  received by Newco  hereunder shall be used as
follows:  (a) $20 million shall be paid to Sub as  contemplated  by the Research
and  Development  Agreement,  (b) $24 million  shall be paid to Sub as a deposit
under the Asset Sale  Agreement,  and (c) the remainder of the proceeds shall be
used to provide working capital for Newco and for the payment of the expenses of
the parties in connection herewith (as contemplated by Section 20). Parent shall
cause Sub to use the  proceeds  paid to Sub in  compliance  with its  obligation
under its various financing arrangements.

7.8.  Financial  Information.  Beginning  three  months  following  the  Initial
      ----------------------
Closing,  Newco shall, and Parent shall cause Newco to, furnish to the Investors
the following financial statements:

(a)  within  115 days  after the end of each  fiscal  year of Newco,  an audited
balance sheet of Newco as of the end of such fiscal year and the related audited
statements  of income,  stockholders'  equity and cash flows for the fiscal year
then  ended,  prepared  in  accordance  with  GAAP  and  certified  by a firm of
independent public accountants selected by the Board of Directors of Newco; and

(b) within 45 days after the end of each  fiscal  month of Newco,  an  unaudited
balance  sheet of  Newco  as of the end of such  fiscal  month  and the  related
unaudited  statements  if  income,  stockholders'  equity and cash flows for the
fiscal  month then  ended,  prepared  in  accordance  with GAAP,  except for the
absence of notes thereto and subject to normal  recurring  year end  adjustments
which will not be  material  in nature or  amount,  and  certified  by the chief
financial officer of Newco (the most recent of which shall be referred to herein
as the "Newco Financial Statements").

7.9.  Survival  of  Representations,   Warranties,   Agreements  and  Covenants;
Indemnifications.

(a) All representations and warranties made in or pursuant to this Agreement and
in or pursuant to the Ancillary  Agreements  shall survive until two years after
the date made (except that the  representations  and warranties made in Sections
4.8(b)(i)  and 6.8(b)(i)  shall  survive until the  expiration of the statute of
limitations  applicable  to any  claims  that may be made by the  holders of the
Series A and Series B 12 1/4%  Senior  Notes due 2008  issued by  Holdings)  and
shall in no way be affected by any  investigation  or  knowledge  of the subject
matter thereof made by or on behalf of the Investor.

(b)  Indemnification  by Parent.  Parent shall  indemnify and hold harmless each
Investor  and  (without  duplication  of  remedies)  Newco from and  against all
damages,  losses,  claims,  liabilities  and  obligations,  costs  and  expenses
(including  attorneys' fees) ("Losses")  arising in any way out of or related to
(i)  the  breach  by  Parent,  Newco,  Motient  Communications  or  Sub  of  any
representation or warranty made by Parent, Newco, Motient  Communications or Sub
herein or in any  Ancillary  Agreement  or in any  document  delivered  pursuant
hereto or thereto, or (ii) the breach by Parent,  Newco, Motient  Communications
or Sub  of any  covenant  or  agreement  contained  herein  or in any  Ancillary
Agreement or in any document delivered pursuant hereto or thereto.  For purposes
of this Section 7.9(b), the terms "material" and "Material Adverse Effect",  and
other materiality  qualifiers in the  representations  and warranties  contained
herein or in the Ancillary  Agreements and in any documents  delivered  pursuant
hereto or thereto,  shall be deemed to refer to  matters,  and groups of related
matters,  that have a financial or economic  impact,  or are capable of having a
financial or economic impact, of $100,000 or more. For purposes of the foregoing
sentence,  matters shall be considered to be within "groups of related  matters"
if they relate to any given Section of the representations and warranties.  (For
purposes  of  illustration  only,  Section 4.6 would be deemed to be breached if
Parent had failed to disclose a liability of $25,000 and a liability of $90,000,
but not if Parent had failed to disclose seven liabilities of $10,000 each.)

(c)  Indemnification  by Newco.  Newco shall  indemnify  and hold  harmless each
Investor from and against all Losses arising in any way out of or related to (i)
the breach by Newco of any representation or warranty made by Newco herein or in
any  document  delivered  pursuant  hereto,  or (ii) the  breach by Newco of any
covenant or agreement  contained  herein or in any document  delivered  pursuant
hereto.

(d) No Duplication  of Remedies.  To the extent any party may have more than one
remedy for any Losses  incurred by it, it may pursue all available  remedies but
in no event  shall be entitled  to collect  and retain any amount  hereunder  in
excess of its Losses.

(e) Indemnification by Investor. Each Investor shall indemnify and hold harmless
Parent from and  against all Losses  arising in any way out of or related to (i)
the breach by such  Investor  of any  representation  or  warranty  made by such
Investor herein or in any document delivered pursuant hereto, or (ii) the breach
by such  Investor  of any  covenant  or  agreement  contained  herein  or in any
document  delivered  pursuant  hereto.  (f)  Notice of  claims.  All  claims for
indemnification  hereunder  shall be resolved in  accordance  with the following
procedures:

          (i) If the party seeking indemnification (the "Indemnified Party") has
     incurred or  reasonably  believes  that it may incur any  Losses,  it shall
     deliver   promptly   written   notice  to  the   indemnifying   party  (the
     "Indemnifying Party"), setting forth the nature and amount of the Losses or
     potential Losses, if possible, and further referencing the sections of this
     Agreement or in any other document delivered pursuant hereto upon which the
     claim for indemnification  for such Losses is based (a "Claim Notice").  If
     an Indemnified  Party receives  notice of a third-party  claim for which it
     intends to seek indemnification  hereunder,  it shall give the Indemnifying
     Party  written  notice  of such  claim,  so that the  Indemnifying  Party's
     defense of such claim under this  Agreement may be timely  instituted.  The
     failure by an  Indemnified  Party to provide such written  notice shall not
     constitute a waiver of the  Indemnified  Party's right to indemnity  unless
     such failure has prejudiced the Indemnifying Party's ability to defend such
     claim, and then only to the extent of such prejudice.

          (ii) If,  after  receiving  a Claim  Notice,  the  Indemnifying  Party
     desires to dispute such claim or the amount claimed in the Claim Notice, it
     shall deliver to the Indemnified Party a written objection to such claim or
     payment  setting forth the basis for disputing such claim or payment.  Such
     notice shall be delivered  within thirty (30) days after the date the Claim
     Notice to which it relates is received  by the  Indemnifying  Party.  If no
     such  notice is  received  within the  aforementioned  30-day  period,  the
     Indemnified  Party  shall be  entitled  to payment for such Losses from the
     Indemnifying Party within ten (10) days of the end of such 30-day objection
     period.

          (iii) if the Indemnifying Party shall agree that it is responsible for
     all amounts that may be recovered in connection  with a third-party  claim,
     action or suit  (including  waiving  any  deductible  or limit  that  might
     otherwise apply under this Section 7.9) the  Indemnifying  Party shall have
     the right to conduct and control through counsel of its own choosing, which
     counsel  shall be  reasonably  acceptable  to the  Indemnified  Party,  any
     third-party claim,  action or suit;  provided,  that the Indemnifying Party
     diligently  contests and defends such claim. The Indemnified Party shall be
     entitled at any time,  at its own cost and expense  (except  that such cost
     and  expense  shall be paid by the  Indemnifying  Party if the  Indemnified
     Party reasonably  determines that the Indemnifying  Party is not adequately
     representing  or,  because of a conflict of  interest,  may not  adequately
     represent the interests of the  Indemnified  Party) to  participate in such
     defense and to be represented by attorneys of its choosing. Except with the
     prior written  consent of the Indemnified  Party no Indemnifying  Party, in
     the  defense of such  claim or  litigation,  shall  consent to entry of any
     judgment or order, interim or otherwise,  or enter into any settlement that
     provides  for  injunctive  or  other   nonmonetary   relief  affecting  the
     Indemnified Party or that does not include as an unconditional term thereof
     the giving by each  claimant or  plaintiff to such  Indemnified  Party of a
     release from all liability with respect to such claim or litigation.

          (iv) In the event that the Indemnifying Party does not elect to defend
     against any third-party  claim,  the  Indemnified  Party may defend against
     such claim in such manner as it may deem  appropriate and the  Indemnifying
     Party  shall be  liable  for any  legal  expenses  reasonably  incurred  in
     connection with such defense; provided, however, that the Indemnified Party
     shall not,  without the consent of the  Indemnifying  Party,  which consent
     shall  not be  unreasonably  withheld,  settle or  consent  to the entry of
     judgment with respect to such third-party claim.

          (v) In the event of any claim by a third  party,  the  parties  hereto
     agree that they will cooperate fully with each other in connection with the
     defense or settlement of such matter.

(g) Limitation on Amounts.  The Indemnifying Party shall not be obligated to pay
any  amounts for  indemnification  under this  Section  7.9 until the  aggregate
indemnification   obligation  of  such  Indemnifying   Party  hereunder  exceeds
$500,000,  whereupon the Indemnifying  Party shall be liable for all amounts for
which  indemnification may be sought which exceed $500,000.  Notwithstanding the
foregoing,  in no event shall the aggregate liability of Parent and Newco to the
Investors  exceed (i)  $50,000,000  if the Investors  Option shall not have been
exercised and consummated,  or (ii) an amount equivalent to $50,000,000 plus the
Option Price, if the Investors Option has been exercised and consummated, except
in the case of fraud or willful breach or any breach by Parent,  Newco or Sub of
the representations and warranties made in Sections 4.8(b)(i) or 6.8(b)(i).

(h) Force  Majeure.  Notwithstanding  any other  provision  of this Section 7.9,
neither  Parent nor Newco shall be liable for any failure of  performance of the
terms of this  Agreement  due  solely  to acts of God,  fires,  floods  or other
natural  catastrophes;  national  emergencies,  insurrections,  riots  or  wars;
strikes,  lockouts,  work stoppages or other labor difficulties  beyond Parent's
reasonable control.

(i) Exclusive remedy.  Indemnification pursuant to this Section 7.9 shall be the
exclusive  remedy for any breach of  representations  and  warranties  or of any
covenant  or  agreement  in this  Agreement  by any  party or any  other  matter
pertaining to this Agreement or the transactions contemplated hereby, other than
Losses  relating  to other  written  agreements  between  the parties and Losses
relating to fraud or  violation of  securities  laws;  provided  that nothing in
Section 7.9 shall prevent any party from obtaining  equitable relief in order to
require another party to perform its obligations hereunder.

Section 8. Termination.
           -----------

8.1.  Termination.  If (i) the Initial  Closing  pursuant to the  conditions set
forth in Section 1.3 hereof  shall not have  occurred on or before June 30, 2000
or (ii) the parties agree prior to such date that it is impossible or reasonably
unlikely to consummate the transactions  contemplated by this Agreement, on such
earlier  date as the  parties  determine,  this  Agreement  and all  rights  and
obligations of the parties hereunder,  except rights and obligations pursuant to
Sections 7.9, 8.1, 8.2, and Sections 9 through 20, shall terminate at 11:59 p.m.
New York time on such date.

8.2.  Parent  Common  Stock  Purchase  Option(a)  . (a) Subject to the terms and
conditions  set  forth  herein,   Parent  hereby  grants  to  each  Investor  an
irrevocable  option  ("Parent  Common Stock Purchase  Option") to purchase up to
such number of shares of Parent Common Stock that equals the result  obtained by
dividing the  Purchase  Price to be paid by such  Investor by the Parent  Option
Price (as defined  below) at a price per share equal to the Parent Option Price.
For the  purposes  hereof,  the "Parent  Option  Price"  shall be (A) $12 if the
Closing Price on the Parent Notice Date (as defined below) is less than or equal
to $24, (B) $20, if the Closing  Price on the Parent Notice Date is greater than
or equal  to $40,  or (C) if the  Closing  Price on the  Parent  Notice  Date is
greater  than $24 and less than $40,  then such number  equal to one-half of the
Closing  Price on the Parent Notice Date;  provided,  that such numbers shall be
equitably  adjusted  in the  event of a stock  split,  stock  dividend  or other
recapitalization  of Parent.  The Parent  Common  Stock  Purchase  Option may be
exercised at any time prior to and until May 4, 2001 ("Parent Exercise Period"),
in the event the Initial  Closing  has not  occurred as a result of either (a) a
willful  breach of this  Agreement  by Parent  or (b)  Parent or Sub shall  have
executed an agreement  with a third-party  which  provides for or relates to the
disposition of all or a substantial  interest in Sub or the Existing Business or
a sale, transfer or other distribution of a substantial portion of the assets or
business  of the  Existing  Business  or stock of Sub,  or a  successor  to Sub.
Nothing  contained  in  this  Section  8.2  shall  act to or be  interpreted  as
relieving Parent of any liability for breach of any provisions contained in this
Agreement.  In the event the Parent Common Stock  Purchase  Option is exercised,
Parent and each  Investor  shall each provide  representations,  warranties  and
legal  opinions  which,  in the case of Parent,  shall  relate to Parent and the
Parent  Common  Stock  subject  to the  Parent  Common  Stock  Purchase  Option,
customary  for financing  transactions,  and Parent shall grant to the Investors
exercising such option the registration  rights contemplated by the Registration
Rights Agreement.

(b) If an Investor  wishes to exercise the Parent Common Stock Purchase  Option,
it shall  deliver  to Parent a written  notice  (the date of receipt of which is
referred  to as the  "Parent  Notice  Date")  specifying  (i) that it intends to
exercise the Parent Common Stock  Purchase  Option and (ii) a place and date not
earlier than three business days nor later than 15 business days from the Parent
Notice Date for the closing of such purchase;  provided,  that if the closing of
the purchase and sale pursuant to the Parent Common Stock  Purchase  Option (the
"Parent Common Stock Purchase  Closing")  cannot be consummated by reason of any
applicable judgment,  decree, order, law or regulation,  the period of time that
otherwise  would run pursuant to this  subsection (b) shall run instead from the
date on which such  restriction on consummation  has expired or been terminated;
and  provided,   further,  that,  without  limiting  the  foregoing,   if  prior
notification  to  or  approval  of  any  regulatory  authority  is  required  in
connection  with such purchase,  such Investor and, if applicable,  Parent shall
promptly  file the  required  notice  or  application  for  approval  and  shall
expeditiously process the same (and Parent shall cooperate with such Investor in
the  filing of any such  notice or  application  and the  obtaining  of any such
approval),  and the period of time that  otherwise  would run  pursuant  to this
subsection (b) shall run instead from the date on which, as the case may be, (i)
any required  notification  period has expired or been  terminated  or (ii) such
approval has been obtained,  and in either event,  any requisite  waiting period
has elapsed.  At the time of the Parent Common Stock  Purchase  Option  Closing,
such Investor shall either be an  "Accredited  Investor" (as defined in Rule 501
under the  Securities  Act) or  deliver  to Parent an  opinion of counsel to the
effect that such securities are freely transferable  without  registration under
the Securities Act. Furthermore,  Parent and such Investor shall take any action
reasonably  requested  by the other to cause the Parent  Common  Stock  Purchase
Closing to occur as promptly as  practicable.  Any exercise of the Parent Common
Stock  Purchase  Option  shall be  deemed  to occur on the  Parent  Notice  Date
relating thereto. Any extensions of the periods specified in this Section 8.2(b)
shall extend the Parent Exercise Period on a day for day basis.

(c) Notwithstanding  anything herein to the contrary, it shall be a condition to
the exercise of this Parent Common Stock Purchase Option and the purchase of the
shares of Parent Common Stock that (i) no preliminary or permanent injunction or
other  order,  decree or ruling  against  the sale or  delivery of the shares of
Parent  Common  Stock  issued  by  any  federal  or  state  court  of  competent
jurisdiction in the United States is in effect at such time, (ii) any applicable
waiting  period  under the HSR Act shall have expired or been  terminated  at or
prior to such time,  (iii) any  approval  required to be  obtained  prior to the
delivery of the shares of Parent Common Stock under the laws of any jurisdiction
shall have been  obtained  and shall be in full force and  effect,  and (iv) all
consents  and  approvals  of any  governmental,  shareholder  and third  parties
necessary for the Parent Common Stock Purchase Closing have been obtained.

(d) At the Parent  Common Stock  Purchase  Closing,  such  Investor  will pay to
Parent  in  immediately  available  funds  by wire  transfer  to a bank  account
designated in writing by Parent the aggregate  purchase  price for the number of
shares to be purchased pursuant to Section 8.2(a).

(e) Immediately  following the Initial Closing, the Parent Common Stock Purchase
Option shall be null, void and of no further effect.

Section  9.  Further  Assurances.  At any time or from  time to time  after  the
Initial Closing,  Parent, Newco, and each Investor, agree to cooperate with each
other,  and at the request of another party,  to execute and deliver any further
instruments  or documents and to take all such further action as the other party
may reasonably  request in order to evidence or effectuate the  consummation  of
the  transactions  contemplated  hereby and to otherwise carry out the intent of
the parties hereunder.

Section 10.  Successors and Assigns.  This Agreement shall bind and inure to the
benefit of Parent and the Investors  and the  respective  successors,  permitted
assigns, heirs and personal representatives of Parent and the Investors,  except
that neither Parent nor Newco may assign its rights and  obligations  under this
Agreement to any person without the prior written  consent of the Investors.  In
addition,  and  whether  or not  any  express  assignment  has  been  made,  the
provisions of this Agreement that are for each Investor's benefit as a purchaser
or holder of Investor  Interests or Parent Common Stock are also for the benefit
of, and  enforceable  by, any  subsequent  holder of such Investor  Interests or
Parent Common Stock. An Investor may assign its rights and obligations hereunder
to  any  affiliate  or to  any  of  its  members  or  partners.  Subject  to the
restrictions  contained  in the LLC  Operating  Agreement,  an Investor may also
assign its rights and  obligations  hereunder,  including its rights pursuant to
Sections 2 and 3 hereof, to any permitted  transferee of its Investor  Interest;
provided that such transferee agrees in writing to be bound by the terms of this
Agreement,  including that the  appropriate  Investors  Group Designee holds the
right to request a Parent  Conversion  as to the Investor  Interest held by such
transferee.

Section 11. Entire  Agreement.  This Agreement and the Ancillary  Agreements and
the other writings referred to herein or delivered  pursuant hereto which form a
part hereof contain the entire  agreement  among the parties with respect to the
subject  matter hereof and supersede all prior  arrangements  or  understandings
with respect thereto.

Section 12. Notices.  All notices,  requests,  consents and other communications
hereunder  to any party  shall be  deemed to be  sufficient  if  contained  in a
written  instrument  delivered  in  person  or  sent  by  telecopy,   nationally
recognized overnight courier or first class registered or certified mail, return
receipt requested,  postage prepaid,  addressed to such party at the address set
forth below or such other  address as may  hereafter be designated in writing by
such party to the other parties:

          (i) if to Parent or Newco, to:

                           Motient Corporation
                           10802 Parkridge Boulevard
                           Reston, Virginia  20191-5416
                           Fax:  (703) 758-6134
                           Attention:    Randy S. Segal, Esq.
                                         Senior Vice President and
                                         General Counsel

                           with a copy to:

                           Hogan & Hartson L.L.P.
                           8300 Greensboro Drive, Suite 1100
                           McLean, Virginia  22102
                           Fax:  (703) 610-6200
                           Attention:    Richard K.A. Becker, Esq.

          (ii) if to the Investors,  to each of the Investor Group  Designees at
     their addresses set forth on Schedule I.


                           with a copy to:

                           Dewey Ballantine LLP
                           1301 Avenue of the Americas
                           New York, New York  10019
                           Fax:  (212) 259-6333
                           Attention:  William J. Phillips, Esq.

                  All such notices, requests,  consents and other communications
shall be deemed to have been given when received.

Section  13.  Amendments.  The terms and  provisions  of this  Agreement  may be
modified or amended,  or any of the  provisions  hereof  waived,  temporarily or
permanently,  pursuant to the written  consent of Parent and each Investor Group
Designee.  No waiver of any of the provisions of this Agreement  shall be deemed
to or shall  constitute a waiver of any other  provision  hereof (whether or not
similar).  No delay on the part of any party in exercising  any right,  power or
privilege hereunder shall operate as a waiver thereof.

Section  14.  Counterparts.  This  Agreement  may be  executed  in any number of
counterparts, and each such counterpart hereof shall be deemed to be an original
instrument,  but  all  such  counterparts  together  shall  constitute  but  one
agreement.

Section 15.  Headings.  The headings of the sections of this Agreement have been
inserted for  convenience of reference only and shall not be deemed to be a part
of this Agreement.

Section 16. Nouns and Pronouns.  Whenever the context may require,  any pronouns
used herein shall include the corresponding masculine, feminine or neuter forms,
and the singular  form of names and pronouns  shall  include the plural and vice
versa.

Section 17.  Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the Commonwealth of Virginia,  without regard to its
principles of conflicts of law that would give effect to the  application of the
law of another  jurisdiction.  Each of the parties hereto hereby irrevocably and
unconditionally  consents to submit to the exclusive  jurisdiction of the courts
of the  Commonwealth  of Virginia and of the United  States of America,  in each
case having jurisdiction over the County of Fairfax,  for any Litigation arising
out of or  relating  to this  Agreement  and the  Ancillary  Agreements  and the
transactions  contemplated  hereby and thereby  (and agrees not to commence  any
Litigation  relating  thereto  except in such courts),  and further  agrees that
service of any process,  summons,  notice or document by U.S. registered mail to
its respective address set forth in this Agreement shall be effective service of
process for any  Litigation  brought  against it in any such court.  Each of the
parties hereto hereby  irrevocably and  unconditionally  waives any objection to
the  laying of venue of any  Litigation  arising  out of this  Agreement  or the
transactions  contemplated  hereby in the courts of the Commonwealth of Virginia
or the United  States of  America,  in each case  having  jurisdiction  over the
County of Fairfax, and hereby further irrevocably and unconditionally waives and
agrees not to plead or claim in any such court that any such Litigation  brought
in any such court has been brought in an inconvenient forum.

Section  18.  Publicity.  Except as may be  required by  applicable  law,  stock
exchange rules or listing agreements,  each of the parties hereto agrees that it
will make no public  statement  regarding the transactions  contemplated  hereby
unless the language and timing of such statement has been approved by Parent and
the Investor.

Section 19.  Severability.  Whenever possible,  each provision of this Agreement
shall be  interpreted  in such manner as to be effective  and valid,  but if any
provision  of this  Agreement  is held to be  invalid  or  unenforceable  in any
respect,  such  invalidity  or  unenforceability  shall not  render  invalid  or
unenforceable any other provision of this Agreement.

Section 20.  Expenses.  Except as otherwise set forth in this Agreement,  if the
Initial Closing shall occur, (i) Newco shall pay all costs and expenses incurred
by the  Investors  (including  up to one  corporate  counsel and one  regulatory
counsel) in connection with the  preparation,  negotiation and execution of this
Agreement  and the  Ancillary  Agreements  and in  connection  with the  Initial
Closing, the Investor Option Closing, and the transactions  contemplated thereby
except for expenses  relating to any Parent  Conversion,  which shall be paid by
the Investors electing to cause a Parent  Conversion,  and (ii) Parent shall pay
all costs and expenses incurred by Parent, Newco (not including those payable by
Newco under the preceding clause (i)) and Sub. In addition, if the Closing shall
occur,  Newco  shall pay its costs and  expenses  incurred  in  connection  with
complying with its obligations  hereunder and under the LLC Operating Agreement,
including  preparing  financial  statements.  If the Initial  Closing  shall not
occur,  each party shall pay its own expenses,  without prejudice to any party's
rights hereunder to damages in the event of a breach hereof.





                            SEPARATE SIGNATURE PAGE
                              INVESTMENT AGREEMENT


         IN WITNESS WHEREOF,  the parties hereto have executed this Agreement as
of the date first above written.

                                     MOTIENT CORPORATION

                                     By:  /s/Gary M. Parsons
                                          Gary M. Parsons, Chairman

                                     MOTIENT SATELLITE VENTURES  LLC
                                     By Motient Corporation, Sole Member

                                     By:  /s/Gary M. Parsons
                                          Gary M. Parsons, Chairman




                            SEPARATE SIGNATURE PAGE
                              INVESTMENT AGREEMENT


     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the date first above written.


                                      TELCOM SATELLITE VENTURES INC.

                                      By:  /s/Rahul Prakash
                                           Name:  Rahul Prakash
                                           Title: President


                            SEPARATE SIGNATURE PAGE
                              INVESTMENT AGREEMENT


     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the date first above written.


                                      COLUMBIA SPACE (QP), INC.

                                      By:  /s/James B. Fleming
                                           Name:  James B. Fleming
                                           Title: President


                                      COLUMBIA SPACE (AI), INC.

                                      By:  /s/James B. Fleming
                                           Name:  James B. Fleming
                                           Title: President


                                      COLUMBIA SPACE PARTNERS, INC.

                                      By:  /s/James B. Fleming
                                           Name:  James B. Fleming
                                           Title: President



                            SEPARATE SIGNATURE PAGE
                              INVESTMENT AGREEMENT


     IN WITNESS WHEREOF, the parties hereto have duly executed this Agreement as
of the date first above written.


                                      SPECTRUM SPACE EQUITY
                                      INVESTORS IV, INC.

                                      By:  /s/Kevin J. Maroni
                                           Name:  Kevin J. Maroni
                                           Title: Chairman and CEO

                                      SPECTRUM SPACE IV PARALLELL, INC.

                                      By:  /s/Kevin J. Maroni
                                           Name:  Kevin J. Maroni
                                           Title: Chairman and CEO

                                      SPECTRUM SPACE IV MANAGERS', INC.

                                      By:  /s/Kevin J. Maroni
                                           Name:  Kevin J. Maroni
                                           Title: Chairman and CEO




                                   SCHEDULE I

                                   INVESTORS




                                                                PURCHASE PRICE FOR
                                    INVESTOR INTERESTS       INVESTOR INTERESTS TO BE            NAME AND ADDRESS OF INVESTOR
   NAME OF INVESTOR                     PURCHASED                    PURCHASED                         GROUP DESIGNEE
==============================     ====================     ==========================           ==============================

                                                                                        
INVESTOR GROUP 1:                  7.2% (7.2                        $18,000,000                  Telcom Satellite Ventures Inc.
- -----------------------------      Investor Units)                                               211 North Union Street
Telcom Satellite  Ventures                                                                       Suite 300
Inc.                                                                                             Alexandria, Virginia 22314
Jurisdiction of                                                                                  Attention:  Hal B. Perkins
Incorporation:  Delaware                                                                         Tel:    (703) 706-3800
                                                                                                 Fax:    (703) 706-3801
==============================     ====================            ============                  ==============================

INVESTOR GROUP 2:
Columbia Space (QP), Inc.

Jurisdiction of                    3.01282560%                      $ 7,532,064                  Columbia Space Partners, Inc.
Incorporation:  Delaware           (3.01282560                                                   211 North Union Street
                                   Investor Units)                                               Suite 300
Columbia Space (AI), Inc.                                                                        Alexandria, Virginia 22314
Jurisdiction of                                                                                  Attention:  James Fleming and
Incorporation:  Delaware                                                                         Don Doering
                                   0.00097280%                      $     2,432                  Tel:    (703) 519-3000
Columbia Space Partners, Inc.      (0.00097280                                                   Fax:    (703) 519-3904
Jurisdiction of                    Investor Units)
Incorporation:  Delaware                                                                         with a copy to:
                                                                                                 Edwards & Angell, LLP
                                                                                                 101 Federal Street

                                   3.3862016%                       $ 8,465,504                  Boston, MA 02100
                                   (3.3862016 Investor Units)                                    Attention:  Stephen
                                                                                                 Meredith, Esq.
                                                                                                 Tel:    (617) 951-2233
                                                                                                 Fax:    (888) 325-9120

==============================     ====================             ===========                  ==============================

INVESTOR GROUP 3:
Spectrum Space Equity              6.18048%                         $15,451,200                  Spectrum Space Equity Investors
Investors IV, Inc.                 (6.18048                                                      IV, Inc.
Jurisdiction of                    Investor Units)                                               One International Place
Incorporation:  Delaware                                                                         29th Floor
                                                                                                 Boston, MA 82110
                                                                                                 Attention:  Kevin Maroni
                                                                                                 Tel:    (617) 464-4600
                                                                                                 Fax:    (617) 464-4601
Spectrum Space IV Parallel,

Inc.

Jurisdiction of

Incorporation:  Delaware           0.14464%                         $   361,600                  with a copy to:
                                   (0.14464                                                      Edwards & Angell, LLP
Spectrum Space IV Managers,        Investor Units)                                               101 Federal Street
Inc.                                                                                             Boston, MA 02100
Jurisdiction of                                                                                  Attention:  Stephen
Incorporation:  Delaware           0.07488%                                                      Meredith, Esq.
                                   (0.07488                         $   187,200                  Tel:    (617) 951-2233
                                   Investor Units)                                               Fax:    (888) 325-9120

==============================     ====================             ===========                  ==============================
Totals                                    20%                       $50,000,000
==============================     ====================             ===========                  ==============================







                                    EXHIBIT A

                                   CERTIFICATE





                                    EXHIBIT B

                             LLC OPERATING AGREEMENT





                                    EXHIBIT C

                          REGISTRATION RIGHTS AGREEMENT





                                    EXHIBIT D

                       RESEARCH AND DEVELOPMENT AGREEMENT





                                    EXHIBIT E

                            CROSS-LICENSING AGREEMENT





                                    EXHIBIT F

                              ASSET SALE AGREEMENT





                                    EXHIBIT G

                        FCC OPINION OF COUNSEL TO PARENT





                                    EXHIBIT H

                                MERGER AGREEMENT







                             Index of Defined Terms

Term                                                                    Section

Accredited Investor                                              Section 5.1 (c)
Ancillary Agreements                                        Section 1.3 (b)(vii)
Applications                                                    Section 4.15 (b)
Asset Sale Agreement                                        Section 1.3 (b)(vii)
Certificate                                                  Section 1.3 (b)(ii)
Claim Notice                                                  Section 7.9 (f)(I)
Closing Price                                                    Section 3.1 (b)
Code                                                                Section 6.12
Commitment                                                           Section 4.7
Contract                                                             Section 4.8
Conversion Notice                                                Section 3.1 (a)
Cross-Licensing Agreement                                     Section 1.3(b)(vi)
Disclosure Schedule                                                    Section 4
Due Diligence                                                    Section 2.2 (c)
Encumbrances                                                    Section 4.11 (b)
Environmental Laws                                                  Section 6.23
ERISA                                                               Section 6.12
Exchange Act                                                     Section 4.5 (a)
Exercise Period                                                  Section 2.2 (a)
Exercising Investor(s)                                            Section 2.2(a)
Existing Business                                   Page 1, First Whereas Clause
FCC                                                 Page 1, First Whereas Clause
FCC Act                                                             Section 4.12
GAAP                                                             Section 4.5 (b)
Hazardous Material                                                  Section 6.23
Holdings                                                             Section 4.8
HSR Act                                                     Section 1.3 (b)(xiv)
Indemnified Party                                             Section 7.9 (f)(i)
Indemnifying Party                                            Section 7.9 (f)(i)
Indenture                                                            Section 4.8
Initial Closing                                                  Section 1.2 (a)
Initial Closing Date                                             Section 1.2 (a)
Initial Investment                                                   Section 1.1
Investment Commitment Date                                       Section 2.2 (g)
Investor                                          Page 1, Introductory Paragraph
Investor Group                                                    Section 3.1(a)
Investor Group Designee                                          Section 3.1 (a)
Investor Interests                                                   Section 1.1
Investors Option                                                     Section 2.1
Investors Option Closing                                         Section 2.2 (g)
Investors Option Closing Date                                    Section 2.2 (g)
Lead Investor                                               Section 1.3 (b)(xii)
Licenses                                                        Section 4.15 (a)
Litigation                                                           Section 4.9
LLC Operating Agreement                                     Section 1.3 (b)(iii)
Losses                                                           Section 7.9 (b)
Material Adverse Effect                                              Section 4.6
Motient Communications                                        Section 1.3(b)(vi)
Newco                                             Page 1, Introductory Paragraph
Newco Disclosure Schedule                                              Section 6
Newco Financial Statements                                           Section 7.8
Newco Options                                                    Section 4.3 (b)
Newco Percentage Interest                                            Section 1.1
Newco Rights                                                        Section 6.24
Newco Update Date                                                Section 2.2 (d)
Notice Closing Price                                              Section 3.1(a)
Offer                                                            Section 2.5 (a)
Offer Closing Notice Date                                        Section 2.5 (b)
Offer Notice                                                     Section 2.5 (a)
Offer Notice Date                                                Section 2.5 (a)
Offeror                                                          Section 2.5 (a)
Option Notice                                                    Section 2.2 (a)
Option Notice Date                                               Section 2.2 (a)
Option Price                                                         Section 2.1
Parent                                            Page 1, Introductory Paragraph
Parent Capital Reorganization                                    Section 3.1 (c)
Parent Common Stock                                              Section 3.1 (a)
Parent Common Stock Purchase Closing                             Section 8.2 (b)
Parent Common Stock Purchase Option                              Section 8.2 (a)
Parent Conversions                                               Section 3.1 (a)
Parent Exchange                                                  Section 3.1 (a)
Parent Exercise Period                                           Section 8.2 (a)
Parent Extraordinary Event                                       Section 3.1 (b)
Parent Merger                                                    Section 3.1 (a)
Parent Notice Date                                               Section 8.2 (b)
Parent Option Price                                              Section 8.2 (a)
Parent Options                                                   Section 4.3 (a)
Parent Reports                                                   Section 4.5 (a)
Parent Securities                                                Section 5.1 (a)
Parent Transfer Letter Agreement                            Section 1.3 (b)(vii)
Permits                                                             Section 4.10
Proprietary Rights                                                  Section 6.24
Public Authority                                                    Section 6.23
Registration Rights Agreement                                Section 1.3 (b)(iv)
Regulatory Disclosure                                            Section 4.15(a)
Research and Development Agreement                            Section 1.3 (b)(v)
SEC                                                              Section 4.5 (a)
Section 2.1 Letter                                           Section 1.3(b)(vii)
Securities Act                                                   Section 2.2 (a)
Securities Laws                                                  Section 4.5 (a)
Sub                                                 Page 1, First Whereas Clause
Subsidiary                                                           Section 4.1