<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
CONSOLIDATED BALANCE SHEETS AND CONSOLIDATED STATEMENTS OF EARNINGS AT AND FOR
THE THREE MONTHS ENDED MARCH 31, 1997 AND IS QUALIFIED IN ITS ENTIRETY BY
REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000820736
<NAME> ORBITAL SCIENCES CORP/DE/
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               MAR-31-1997
<CASH>                                          29,249
<SECURITIES>                                    10,022
<RECEIVABLES>                                  148,983
<ALLOWANCES>                                   (1,602)
<INVENTORY>                                     23,459
<CURRENT-ASSETS>                               217,834
<PP&E>                                         203,237
<DEPRECIATION>                                (73,200)
<TOTAL-ASSETS>                                 515,121
<CURRENT-LIABILITIES>                          138,288
<BONDS>                                         29,346
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           322
<OTHER-SE>                                     335,512
<TOTAL-LIABILITY-AND-EQUITY>                   515,121
<SALES>                                        122,112
<TOTAL-REVENUES>                               122,112
<CGS>                                           88,434
<TOTAL-COSTS>                                   88,434
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                   142
<INTEREST-EXPENSE>                                  97
<INCOME-PRETAX>                                  5,660
<INCOME-TAX>                                       566
<INCOME-CONTINUING>                              5,094
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     5,094
<EPS-PRIMARY>                                     0.16
<EPS-DILUTED>                                     0.16