Exhibit 17.1

         Resignation Letter of James D. Dondero Dated February 14, 2006


                                                               February 14, 2006



To:      The Board of Directors of Motient Corporation

         I have lost confidence in current management and the other members of
the Board of Directors of Motient Corporation and believe that the actions being
taken by management and other members of the Board do not serve the best
interests of all stockholders. As a result, I am left with no choice but to
resign from the Board of Directors of Motient Corporation, effective
immediately. Because I continue to believe that the Company has great potential,
Highland Capital Management, L.P. is announcing today its intention to propose a
group of highly qualified and predominantly independent directors to replace the
existing Board of Directors.


                                   Sincerely,

                                   /s/ James D. Dondero
                                   ---------------------
                                   James D. Dondero