SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13D


                    Under the Securities Exchange Act of 1934


                           Orion Network Systems, Inc.
                           ---------------------------
                                (Name of Issuer)

                     Common Stock, $.01 par value per share
                     --------------------------------------
                         (Title of Class of Securities)


                                   68628K 10 4
                      -------------------------------------
                      (CUSIP Number of Class of Securities)

                             Stephen M. Piper, Esq.
                            Associate General Counsel
                           Lockheed Martin Corporation
                              6801 Rockledge Drive
                            Bethesda, Maryland 20817
                                  301-897-6177
- --------------------------------------------------------------------------------
            (Name, Address and Telephone Number of Persons Authorized
                     to Receive Notices and Communications)

                                January 31, 1997
                                ----------------
                          (Date of Event which Requires
                            Filing of this Statement)

                  If the  filing  person has  previously  filed a  statement  on
         Schedule  13G to report the  acquisition  which is the  subject of this
         Schedule 13D, and is filing this Schedule  because of Rule  13d-1(b)(3)
         or (4), check the following box: |_|











                                  SCHEDULE 13D


- --------------------------------------------

CUSIP NO. 69628K 10 4
- --------------------------------------------

================================================================================
    1.        NAME OF REPORTING PERSON
              S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                       Lockheed Martin Corporation
- --------------------------------------------------------------------------------
    2.        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                  (a) | |
                                                                  (b) |X|
- --------------------------------------------------------------------------------
    3.        SEC USE ONLY

- --------------------------------------------------------------------------------
    4.        SOURCE OF FUNDS

                       N/A
- --------------------------------------------------------------------------------
    5.        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEMS 2(d) OR 2(e)                          | |

- --------------------------------------------------------------------------------
    6.        CITIZENSHIP OR PLACE OF ORGANIZATION

                       Maryland
- --------------------------------------------------------------------------------
                              7.         SOLE VOTING POWER
                 
                                                    1,368,340
        NUMBER OF
          SHARES
       BENEFICIALLY        -----------------------------------------------------
        OWNED BY             8.         SHARED VOTING POWER
          EACH
        REPORTING                                   0
       PERSON WITH          ----------------------------------------------------
                              9.         SOLE DISPOSITIVE POWER

                                                    1,368,340
                           -----------------------------------------------------
                             10.         SHARED DISPOSITIVE POWER

                                                    0
- --------------------------------------------------------------------------------
    11.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                   1,368,340
- --------------------------------------------------------------------------------
    12.       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
              SHARES                                                  | |

- --------------------------------------------------------------------------------
    13.       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                       11.14%
- --------------------------------------------------------------------------------
    14.       TYPE OF REPORTING PERSON

                       HC
================================================================================


                               Page 2 of 16 Pages






                                  SCHEDULE 13D


- --------------------------------------------

CUSIP NO. 68628K 10 4
- --------------------------------------------

================================================================================
    1.        NAME OF REPORTING PERSON
              S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

                       Lockheed Martin Commercial Launch Services, Inc.
- --------------------------------------------------------------------------------
    2.        CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                   (a) | |
                                                                   (b) |X|
- --------------------------------------------------------------------------------
    3.        SEC USE ONLY

- --------------------------------------------------------------------------------
    4.        SOURCE OF FUNDS

                       WC and 00
- --------------------------------------------------------------------------------
    5.        CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
              PURSUANT TO ITEMS 2(d) OR 2(e)                          | |

- --------------------------------------------------------------------------------
    6.        CITIZENSHIP OR PLACE OF ORGANIZATION

                       Delaware
- --------------------------------------------------------------------------------
                              7.         SOLE VOTING POWER

                                              1,368,340
        NUMBER OF
          SHARES
       BENEFICIALLY        -----------------------------------------------------
         OWNED BY             8.         SHARED VOTING POWER
          EACH
        REPORTING                             0
       PERSON WITH          ----------------------------------------------------
                              9.         SOLE DISPOSITIVE POWER

                                              1,368,340
                           -----------------------------------------------------
                             10.         SHARED DISPOSITIVE POWER

                                              0
- --------------------------------------------------------------------------------
    11.       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                   1,368,340
- --------------------------------------------------------------------------------
    12.       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
              SHARES                                                  | |

- --------------------------------------------------------------------------------
    13.       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

              11.14%
- --------------------------------------------------------------------------------
    14.       TYPE OF REPORTING PERSON

                       CO
================================================================================


                               Page 3 of 16 Pages






ITEM 1.           SECURITY AND ISSUER

                  The class of equity  securities  to which  this  statement  on
Schedule 13D relates is the common stock,  $.01 par value per share (the "Common
Stock"), of Orion Network Systems, Inc. (the "Company"), a Delaware corporation.
The  principal  executive  offices of the Company  are located at 2440  Research
Boulevard, Suite 400, Rockville, Maryland 20850.


ITEM 2.           IDENTITY AND BACKGROUND

                  This  statement  on  Schedule  13D is being  filed  jointly on
behalf of the following  persons  (collectively,  the  "Reporting  Persons") (1)
Lockheed Martin Corporation,  a Maryland  corporation  ("LMC"), and (2) Lockheed
Martin Commercial Launch Services, Inc., a Delaware corporation ("LMCLS").

                  LMCLS is a commercial  launch  services  provider and provided
launch  services to Orion Atlantic as the launch  subcontractor.  The address of
the principal  business and principal office of LMCLS is 12999 Deer Creek Canyon
Road, Littleton, Colorado 80127.

                  LMC owns all of the capital  stock of LMCLS and its  principal
business  is  aerospace/defense.  The  address  of the  principal  business  and
principal office of LMC is 6801 Rockledge Drive, Bethesda, Maryland 20817.

                  The name, business address, citizenship, present and principal
occupation or employment,  and the name,  principal  business and address of any
corporation or organization in which each such employment is conducted,  of each
executive officer or member of the Board of Directors,  as applicable,  of LMCLS
and LMC are set forth on Schedules A and B, respectively, attached hereto.

                  During the past five (5) years,  neither any of the  Reporting
Persons nor, to the best knowledge of any of the Reporting  Persons,  any of the
other  persons  listed  on  Schedules  A and B  attached  hereto,  has  been (i)
convicted in a criminal  proceeding  (excluding  traffic  violations  or similar
misdemeanors)  or  (ii)  a  party  to  a  civil  proceeding  of  a  judicial  or
administrative body of competent jurisdiction and as a result of such proceeding
was or is  subject  to a  judgment,  decree  or  final  order  enjoining  future
violations of, or prohibiting or mandating  activities subject to, United States
federal or state  securities  laws or finding any violation with respect to such
laws.

                  Although LMC has not been convicted in a criminal  proceeding,
and has not been subject to a judgment,  decree or final order,  in each case of
the type described in the immediately preceding paragraph,  Lockheed Corporation
(one of the predecessor corporations to LMC) entered into a plea agreement

                               Page 4 of 16 Pages






dated January 27, 1995 with the United States of America with respect to certain
violations. For further information concerning the plea agreement and the events
out of  which  it  arose,  see the  description  contained  in the  Joint  Proxy
Statement/  Prospectus,  page 54, under the caption  "Lockheed Plea  Agreement,"
which is contained in Registration  Statement No. 33- 57645 on Form S-4 filed by
LMC on February 9, 1995.


ITEM 3.           SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION

                  A predecessor to the business of LMCLS acquired 239,769 shares
of common  stock  from  Orion  Network  Systems,  Inc.,  now named  Orion  Oldco
Services, Inc. ("Orion Oldco"), in a private placement on September 11, 1989 for
an aggregate  purchase  price of  $2,347,826.40.  Such number of shares is after
giving effect to two reverse stock splits  effected  after the date of issuance.
Such  shares of common  stock were  ultimately  acquired  by LMCLS  through  the
acquisition of such business.  Pursuant to a merger  transaction  (the "Merger")
which occurred on January 31, 1997, Orion Oldco became a wholly owned subsidiary
of the  Company.  As a result of the Merger,  LMCLS  beneficially  owns  239,769
shares of Common  Stock of the Company  which it  received  in exchange  for the
239,769 shares of common stock of Orion Oldco previously held by it.

                  On December 16, 1996, Orion Oldco announced that it had agreed
to  acquire  all of the  interests  which it did not  already  own in the  Orion
Atlantic partnership.  The Agreement to acquire such interests was pursuant to a
Section  351  Exchange  Agreement  and Plan of  Conversion  dated June 1996,  as
amended  pursuant  to a First  Amendment  thereto  dated  December  1996  (as so
amended, the "Exchange Agreement").

                  Pursuant  to  the  Exchange  Agreement,  Orion  Oldco,  now  a
wholly-owned  subsidiary of the Company as described above,  agreed, among other
things,  to have the Company issue shares of Series C 6%  Cumulative  Redeemable
Convertible Preferred Stock (the "Series C Preferred Stock") in exchange for the
limited  partnership  interests in Orion  Atlantic held by all limited  partners
other than Orion Oldco or its subsidiaries (the "Exchanging Partners") and other
rights relating thereto (the "Exchange"). As a result of the Exchange, which was
consummated on January 31, 1997, the Company became the direct or indirect owner
of all of the partnership interests in Orion Atlantic. In addition,  the Company
acquired certain rights currently held by the Exchanging Partners, including the
Exchanging  Partners'  rights to receive  repayment of various  advances made to
Orion Atlantic.

                  Pursuant to the  Exchange,  LMCLS  received  19,750  shares of
Series C Preferred Stock.  Subject to the  preferential  rights of certain other
shares of capital stock of the Company, the Series C Preferred Stock is entitled


                               Page 5 of 16 Pages






to  receive  dividents  that  accrue  daily at the per  annum  rate of 6% of the
Liquidation  Value ($1,000 per share).  Such  dividends are payable  exclusively
(except in the event of liquidation) in the Company's  Common Stock.  The number
of shares of Common Stock  distributable as a dividend on each share of Series C
Preferred  Stock is  calculated  based on the market  price of such Common Stock
under a formula set forth in the  Certificate of  Designations  for the Series C
Preferred Stock (the "Certificate of Designations").

                  At any time and from time to time after the issuance  thereof,
any holders of Series C Preferred  Stock may convert any or all of the shares of
Series C Preferred  Stock  (including any fraction  thereof) held by such holder
into a number of shares of Common  Stock  equal to the sum of (a) the  number of
shares of Common Stock computed by multiplying  the number of shares of Series C
Preferred  Stock to be  converted  by $1,000 and  dividing the result by $17.50,
subject to adjustment,  plus (b) the number of shares of Common Stock that would
be payable if all accrued but unpaid  dividends  were  declared  and paid on the
shares of Series C Preferred Stock to be converted.  Accordingly, without giving
effect to any shares of Common  Stock  issuable in respect of accrued but unpaid
dividends,  1,128,571 shares of Common Stock are issuable upon conversion of the
Series C Preferred Stock held by LMCLS.

                  The Closing of the Exchange  Agreement was  conditioned  upon,
among other  conditions,  the  satisfaction  or waiver by LMCLS of the condition
that LMCLS and Matra Marconi  Space UK Limited  enter into a subcontract  to the
Orion II Satellite Contract relating to the launch of Orion II. In addition, the
obligations  of the  Exchanging  Partners  under  various  financing  and  other
agreements  relating to the Orion Atlantic  partnership were terminated upon the
consummation of the Exchange.

                  The  information  set forth in  Exhibits  2, 3 and 4 hereto is
hereby expressly  incorporated herein by reference and the response to Item 3 of
this statement on Schedule 13D is qualified in its entirety by the provisions of
such exhibit.


ITEM 4.           PURPOSE OF TRANSACTION

                  As  described  in item 3 above,  LMCLS (i) acquired the common
stock of Orion Oldco  previously  held by it pursuant to its  acquisition of the
business by its  predecessor,  (ii)  acquired  the shares of Common Stock of the
Company in exchange  for such  shares of Orion Oldco  pursuant to the Merger and
(iii) acquired the shares of Series C Preferred Stock held by it pursuant to the
Exchange  Agreement.  LMCLS  continues to hold the Common Stock and the Series C
Preferred  Stock  held by it for  investment  purposes.  None  of the  Reporting
Persons has any  intention  of  acquiring  control  over the  Company;  however,
depending upon market and other conditions,  LMCLS or its affiliates may acquire
additional shares of Common Stock for investment purposes if such shares of

                               Page 6 of 16 Pages






Common Stock become  available at prices that are  attractive  to them,  or may,
subject to any restrictions  contained in the Resales Restrictions Agreement (as
defined below) or under applicable  securities laws, dispose of all or a portion
of the Common Stock that they currently own or may hereinafter acquire.

                  Except  as  disclosed  in this  Schedule  13D,  the  Reporting
Persons do not have any plans or proposals  of the type set forth in  Paragraphs
(a) through (j) of Item 4 of Schedule 13D.


ITEM 5.           INTEREST IN SECURITIES OF THE ISSUER

                  LMCLS  may  be  deemed  to be  the  beneficial  owner  of  the
1,368,340  shares of Common Stock (the "LMCLS  Shares")  directly owned by it or
issuable upon  conversion of the Series C Preferred  Stock directly owned by it,
or 11.14% of the Common Stock outstanding.  LMCLS has the sole power to vote and
the sole power to dispose of the LMCLS Shares.

                  LMC, as the sole  stockholder of LMCLS,  may be deemed for the
purposes of Rule 13d-3 under the Act, to  beneficially  own indirectly the LMCLS
Shares.

                  The  percentage  of the Common Stock  outstanding  reported as
beneficially  owned by each Reporting  Person herein on the date hereof is based
upon the 11,554,626 shares of Common Stock actually  outstanding as of the close
of  business on January  31,  1997  (after  giving  effect to the Merger and the
Exchange) plus the 1,128,571  shares of Common Stock issuable upon conversion of
the Series C Preferred  Stock held by LMCLS (but  without  giving  effect to any
shares  issuable  in  respect of accrued  but unpaid  dividends  on the Series C
Preferred  Stock and  without  giving  effect to the  issuance  of any shares of
Common Stock upon exercise of options or warrants or upon conversion or exchange
of convertible or exchangeable securities held by any other person).


ITEM 6.           CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR
                  RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER

                  The  response to Item 3 of this  statement  on Schedule 13D is
incorporated herein by reference.

                  The holders of Series C Preferred  Stock are  entitled to vote
on all matters submitted to the Company's  stockholders for a vote together with
the holders of the  Company's  Common Stock,  Series A 8% Cumulative  Redeemable
Convertible  Preferred Stock and Series B 8% Cumulative  Redeemable  Convertible
Preferred  Stock,  voting  together as a single class.  The holder of a share of
Series C Preferred  Stock  (including  fractional  shares) will be entitled to 1
vote for each whole share of the Company's Common Stock issuable upon conversion
of such share of Series C Preferred  Stock.  See the Certificate of Designations


                               Page 7 of 16 Pages






attached hereto as Exhibit 4 for the powers,  rights and preferences of, and the
qualifications, limitations and restrictions of, the Series C Preferred Stock.

                  Pursuant  to a  Registration  Rights  Agreement  entered  into
pursuant to the Exchange  Agreement,  the Exchanging  Partners (including LMCLS)
were granted  certain shelf,  demand and  "piggyback"  registration  rights with
respect to the shares of Common  Stock or other  securities  issued or  issuable
upon  conversion  of the  Series C  Preferred  Stock or issued as  dividends  or
distributions pursuant to the Certificate of Designations.  See the Registration
Rights Agreement attached as Exhibit D to the Exchange Agreement.

                  Pursuant to a Resales  Restriction  Agreement  entered into on
January 31, 1997 (the "Resales Restriction  Agreement"),  each of the Exchanging
Partners  agreed,  among other  things,  that it will not transfer any shares of
Common Stock issued upon  conversion of shares of Series C Preferred Stock or as
dividends on Series C Preferred Stock (the "Affected Shares") for 180 days after
the issuance of the Series C Preferred  Stock without the prior written  consent
of the Company,  unless such a transfer is to an affiliate or does not involve a
public distribution or public offering or occurs as the result of certain events
set forth in the Resales Restriction Agreement,  and is conducted as provided in
the Resales Restriction Agreement. Also, each of the Exchanging Partners agreed,
pursuant to the Resales  Restriction  Agreement,  until  January 31, 2002 not to
transfer during any 90- day period Affected Shares that  collectively  represent
more than 25% of the  aggregate  number of shares of Common Stock  issuable upon
the  conversion  of the Series C Preferred  Stock  received  by such  Exchanging
Partner  pursuant to the  Exchange  Agreement  or as  dividends  on the Series C
Preferred Stock,  except as provided in the Resales Restriction  Agreement.  See
the  Resales  Restriction  Agreement  attached  as  Exhibit  E to  the  Exchange
Agreement.

                  The  information  set forth in  Exhibits  4, 5 and 6 hereto is
hereby expressly  incorporated herein by reference and the response to Item 3 of
this statement on Schedule 13D is qualified in its entirety by the provisions of
such exhibit.


ITEM 7.           MATERIAL TO BE FILED AS EXHIBITS

                  The following documents are included as exhibits hereto:

                  1.       Joint Filing Agreement pursuant to Rule 13d-1(f).

                  2.       Section 351 Exchange Agreement and Plan of
                           Conversion (the "Exchange Agreement"), dated as of
                           June 1996, among International Private Satellite
                           Partners, L.P., Orion Network Systems, Inc. (now
                           named Orion Oldco Services, Inc.), Orion Satellite

                               Page 8 of 16 Pages






                           Corporation and the Exchanging Partners,  and certain
                           exhibits   thereto   (incorporated  by  reference  to
                           Exhibit  10 of  Current  Report  on Form 8K of  Orion
                           Network Systems, Inc. filed December 20, 1996).

                  3.       First Amendment to Exchange Agreement
                           (incorporated by reference to Exhibit 10.45 in
                           Registration Statement 333-19795 on Form S-4 of
                           Orion Newco Services, Inc.).

                  4.       Form of Certificate of Designations of Series C
                           Preferred Stock (incorporated by reference to
                           Exhibit 4.3 of Registration Statement on Form 8-B
                           of Orion Newco Services, Inc. filed on January 31,
                           1997).

                  5.       Form of Registration Rights Agreement (Exhibit D
                           to Item 2 above).

                  6.       Resales Restriction Agreement (Exhibit E to Item 2
                           above).

                               Page 9 of 16 Pages









                                    SIGNATURE

                  After  reasonable  inquiry and to the best of my knowledge and
belief,  I certify  that the  information  set forth in this  statement is true,
complete and correct.

Date:  February 10, 1997

                                            LOCKHEED MARTIN CORPORATION



                                            By:   /s/ Raymond S. Colladay
                                               --------------------------
                                                 Raymond S. Colladay
                                                 President - Astronautics



                                    SIGNATURE

                  After  reasonable  inquiry and to the best of my knowledge and
belief,  I certify  that the  information  set forth in this  statement is true,
complete and correct.

Date: February 10, 1997

                                            LOCKHEED MARTIN COMMERCIAL LAUNCH
                                            SERVICES, INC.



                                            By:   /s/ Jeffrey D. MacLauchlan
                                               -----------------------------
                                                 Jeffrey D. MacLauchlan
                                                 Vice President and Assistant
                                                     Treasurer




                               Page 10 of 16 Pages






                                                                     SCHEDULE A

                        Executive Officers and Directors
                                       of
                Lockheed Martin Commercial Launch Services, Inc.

                  The names of the  Directors  and the  names and  titles of the
Executive   Officers  of  LMCLS  and  their  business  addresses  and  principal
occupations  are set forth below.  Unless  otherwise  indicated,  the  principal
business  address of each of the persons listed below is 12999 Deer Creek Canyon
Road, Littleton, Colorado 80127. Unless otherwise indicated, each occupation set
forth  opposite an  individual's  name refers to LMCLS and each  individual is a
United States citizen and an employee of LMC.


Name, Business Address           Present Principal Occupation
                                 and Title

Michael R. Wash                  President and Director
101 West Broadway
Suite 2000
San Diego, CA  92101

Michael W. Wynne                 Vice President and General
12257 State Highway 121              Manager, Space Launch
Mail Stop 5000                       Systems, of LMC and Director
Littleton, Colorado 80127            of LMCLS

Raymond Colladay                 President - Astronautics of
                                   LMC and Director of LMCLS

Jeffrey D. MacLauchlan           Vice President, Assistant
                                     Treasurer and Director of
                                     LMCLS and Vice President,
                                     Business Management of LMC
                                     Astronautics

Janet L. McGregor                Treasurer of LMCLS and Vice
6801 Rockledge Drive                 President and Chief
Bethesda, Maryland 20817             Financial Officer of LMC's
                                     Electronics Sector

Lillian M. Tripett               Secretary of LMCLS and Vice
6801 Rockledge Drive                 President, Associate General
Bethesda, Maryland 20817             Counsel and Secretary of LMC

Michael J. Kramer                Assistant Secretary of LMCLS
                                 and Vice President and General
                                 Counsel of LMC Astronautics



                              Page 11 of 16 Pages





                                                                    SCHEDULE B


                        Executive Officers and Directors
                                       of
                           Lockheed Martin Corporation


           The names of the  Directors and the names and titles of the Executive
Officers of LMC and their business  addresses and principal  occupations are set
forth below.  Unless  otherwise  indicated,  the business address of each of the
Executive  Officers and  Directors  of LMC is 6801  Rockledge  Drive,  Bethesda,
Maryland 20817. Unless otherwise  indicated,  each occupation set forth opposite
an  individual's  name  refers  to LMC and each  individual  is a United  States
citizen.


Name, Business Address                   Present Principal Occupation
                                         and Title

Norman R. Augustine                      Chairman & Chief Executive
                                         Officer and Director

James A. Blackwell, Jr.                  President & Chief Operating
                                         Officer of Aeronautics Sector

Marcus C. Bennett                        Executive Vice President,
                                         Chief Financial Officer and
                                         Director

Melvin R. Brashears                      President & Chief Operating
                                         Officer of Space & Strategic
                                         Missiles Sector

Vance D. Coffman                         President & Chief Operating
                                         Officer and Director

Raymond S. Colladay                      President Astronautics
12999 Deer Creek Canyon Road
Littleton, Colorado 80127

Thomas A. Corcoran                       President & Chief Operating
                                         Officer Electronics Sector

Dain M. Hancock                          President Tactical Aircraft
Lockheed Boulevard                       Systems
Ft. Worth, Texas 76108
P.O. Box 748

K. Michael Henshaw                       President Missiles & Space
1111 Lockheed Way
P.O. Box 3504
Sunnyvale, California 94088

John R. Kreik                            President Sanders
65 Spit Brook Road
Nashua, New Hampshire 03061


                               Page 12 of 16 Pages








Frank C. Lanza                            Executive Vice President

John S. McLellan                          President Aeronautical Systems

Frank H. Menaker, Jr.                     Executive Vice President &
                                          General Counsel

Albert Narath                             President & Chief Operating
                                          Officer Energy & Environment
                                          Sector

Robert E. Rulon                           Vice President & Controller

Walter E. Skowronski                      Vice President & Treasurer

Peter B. Teets                            President & Chief Operating
                                          Officer Information and
                                          Services Sector

Lynne V. Cheney                           Director of LMC and W.H.
                                          Brady, Jr.
                                          Distinguished Fellow, American
                                          Enterprise Institute

Houston I. Flournoy                       Director of LMC and Special
                                          Assistant to the President,
                                          Governmental Affairs,
                                          University of Southern
                                          California

James F. Gibbons                          Director of LMC and Special
                                          Counsel to the President for
                                          Industry Relations, Stanford
                                          University

Edward E. Hood, Jr.                       Director of LMC and Retired
                                          Vice Chairman, General
                                          Electric Company

Caleb B. Hurtt                            Director of LMC and Retired
                                          President and Chief Operating
                                          Officer, Martin Marietta
                                          Corporation

Gwendolyn S. King                         Director of LMC and Senior
                                          Vice President, Corporate and
                                          Public Affairs, PECO Energy
                                          Company

Vincent N. Marafino                       Director of LMC and Retired
                                          Executive Vice President,
                                          Lockheed Martin Corporation

Eugene F. Murphy                          Director of LMC and President
                                          & Chief Executive Officer, GE
                                          Aircraft Engines


                               Page 13 of 16 Pages








Allen E. Murray                           Director of LMC and Retired
                                          Chairman & Chief Executive
                                          Officer, Mobil Corporation

Frank Savage                              Director of LMC and Chairman,
                                          Alliance Capital Management
                                          International

Daniel M. Tellep                          Director of LMC and Retired
                                          Chairman of the Board and
                                          Chief Executive Officer,
                                          Lockheed Martin Corporation

Carlisle A.H. Trost                       Director of LMC and Retired
                                          Chief of Naval Operations

James R. Ukropina                         Director of LMC and Partner,
                                          O'Melveny & Myers

Douglas C. Yearley                        Director of LMC and Chairman,
                                          President and Chief Executive
                                          Officer, Phelps Dodge
                                          Corporation



                               Page 14 of 16 Pages






                                  EXHIBIT INDEX

           1.         Joint Filing Agreement pursuant to Rule 13d-1(f).

           2.         Section 351 Exchange Agreement and Plan of Conversion
                      (the "Exchange Agreement"), dated as of June 1996,
                      among International Private Satellite Partners, L.P.,
                      Orion Network Systems, Inc. (now named Orion Oldco
                      Services, Inc.), Orion Satellite Corporation and the
                      Exchanging Partners, and certain exhibits thereto
                      (incorporated by reference to Exhibit 10 of Current
                      Report on Form 8K of Orion Network Systems, Inc.
                      filed December 20, 1996).

           3.         First Amendment to Exchange Agreement (incorporated
                      by reference to Exhibit 10.45 in Registration
                      Statement 333-19795 of Form S-4 on Orion Newco
                      Services, Inc.).

           4.         Form of Certificate of Designations of Series C
                      Preferred Stock (incorporated by reference to Exhibit
                      4.3 of Registration Statement on Form 8-B of Orion
                      Newco Services, Inc. filed on January 31, 1997).

           5.         Form of Registration Rights Agreement (Exhibit D to
                      Item 2 above).

           6.         Resales Restriction Agreement (Exhibit E to Item 2
                      above).


                               Page 15 of 16 Pages





                                                                   Exhibit 1


                             JOINT FILING AGREEMENT

In accordance  with Rule 13d-1(f) under the Securities  Exchange Act of 1934, as
amended, each of the persons named below agrees to the joint filing on behalf of
each of them of a Statement on Schedule 13D (including  amendments thereto) with
respect to the common stock, $.01 par value per share, of Orion Network Systems,
Inc.,  a  Delaware  corporation,  and  further  agrees  that this  Joint  Filing
Agreement  be  included  as  an  exhibit  to  such  filings  provided  that,  as
contemplated  by Rule  13d-1(f)(l)(ii),  no person shall be responsible  for the
completeness or accuracy of the information  concerning the other persons making
the  filing,  unless  such  person  knows or has  reason  to  believe  that such
information  is  inaccurate.  This Joint Filing may be executed in any number of
counterparts,  all of which taken  together  shall  constitute  one and the same
instrument.

Date:  September 10, 1997

LOCKHEED MARTIN COMMERCIAL LAUNCH
SERVICES,INC.


By:   /s/ Jeffrey D. MacLauchlan
   --------------------------------------------
         Jeffrey D. MacLauchlan
         Vice President and Assistant Treasurer

LOCKHEED MARTIN CORPORATION


By:   /s/ Raymond S. Colladay
   --------------------------------------------
         Raymond D. Colladay
         President - Astronautics

                               Page 16 of 16 Pages