Exhibit 10.15.6



                    ARIANESPACE CONFIDENTIAL AND PROPRIETARY



This Amendment #1 to the Side Letter to the Launch Services  Agreement  95.5.933
between the Parties is entered into between:

ARIANESPACE  S.A., a company  organized  under the laws of France and having its
principal office at Boulevard de l'Europe, 91006 EVRY, France.

and

PanAmSat Corporation a company organized under the laws of the State of Delaware
with principal  offices located at One Pickwick Plaza,  Greenwich,  Connecticut,
U.S.A.


Reference is made to the Launch Services  Agreement  95.5.933  executed  between
PanAmSat  Corporation and ARIANESPACE on December 20th,  1995, for the Launch of
PanAmSat  Satellites  (said  Agreement  being  hereinafter  referred  to as  the
"Agreement"  and the  Launches  covered  under said  Agreement  being  hereafter
referred to as the "Launches").

On December 20th 1995,  the Parties  entered into a side letter to the Agreement
("the Side  Letter").  This  Amendment #1 to the Side Letter amends and replaces
the terms of the Side Letter.

The two Parties agree that the conditions  listed  hereafter shall be applicable
to the Launches.  Unless otherwise indicated,  words defined under the Agreement
shall have the same meaning in the present Amendment #1 to the Side Letter.


I.

In order to give PanAmSat greater schedule  flexibility, the Agreement foresees 
the use of either the Ariane 4 or the Ariane 5 Launch Vehicles to perform the 
Launches.

The Parties agree that the Ariane 5 Launch Vehicle shall be the preferred Launch
Vehicle for the  Launches  and that  ARIANESPACE  shall use its best  efforts to
affect Ariane 5 Launch  Vehicles to the Launches  under the terms and conditions
of the Agreement.


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II.

If despite  these  efforts,  ARIANESPACE  is unable to affect an Ariane 5 Launch
Vehicles to any of the Launches within the contractual  launch schedule provided
for under the Agreement,  ARIANESPACE  shall inform PanAmSat as soon as possible
and  PanAmSat  shall  have the  option to wait for the next  scheduled  Ariane 5
Launch  Vehicle for which  there is a Launch  Possibility  or have the  relevant
Satellite Launched as scheduled on an Ariane 4 Launch Vehicle.

In the event  that  ARIANESPACE  shall be obliged  to  postpone  the launch of a
satellite of another  client of  ARIANESPACE  ("Third Party Launch") in order to
make  available  a  Launch  Possibility  for  Customer's  Satellite,   then,  in
determining  which  satellite to retain on such Third Party Launch,  ARIANESPACE
shall retain the satellite which is compatible in size with PanAmSat's Satellite
or, if two or more  satellites on such Third Party Launch are compatible in size
and in class with  PanAmSat's  Satellite,  ARIANESPACE  shall apply the criteria
numbered  (1)  to  (3)  inclusive  in,  and in the  order  which  is set  out in
Sub-paragraph 11.3.2. of this Article 11 of the Agreement.


III.

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[***]     Filed separately with the Commission pursuant to a request for 
          confidential treatment.


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IV.

Notwithstanding the provisions of Paragraphs I to III above, the Parties agree 
that:

a)   Paragraph  I to III shall  not be  applicable  to Firm  Launch #2 under the
     Agreement if said Launch is  accelerated  under the provisions of Paragraph
     11.5  of  the  Agreement  to  a  date  prior  to 1  January  1999,  and  

b)   ***************************************************************************
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V.


Notwithstanding  the terms of Paragraphs  4.1.5 and 13.1.5 of the Agreement,  in
the event that, under the Agreement  and/or this Side Letter,  PanAmSat shall be
entitled to a Reflight for an initial  Satellite of a baseline  mass of 3450 kg,
Customer shall, at the time of order of the Reflight, have the right to increase
the mass of the  Satellite  object of the Reflight up to a baseline mass of 4500
kg.  Said  increase  in mass shall be subject to the  payment of a sum of [*****
**********************]  ("the Optional Mass Price").  This sum shall be due and
payable at the time of order of the Replacement  Launch. The Optional Mass Price
is valid  for a Launch  to take  place  prior to 1 April  1999 and for  Launches
beyond this date, this price shall be increased by a factor of  [**************]
per the number of calendar  quarters or portion thereof between 1 April 1999 and
the first day of the initial Launch Period for the Reflight.


[***]     Filed separately with the Commission pursuant to a request for 
          confidential treatment.


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VI.


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VII.

The Parties agree that in the event that PanAmSat declines an available Ariane 4
Launch  Vehicle  proposed by ARIANESPACE in order to wait for an Ariane 5 Launch
Vehicle  under the  provisions  of  Paragraph II hereof,  the delay  between the
Ariane 4 Launch  Period or Launch Slot and the Ariane 5 Launch  Period or Launch
Slot shall not be  considered  to  constitute  a  postponement  of the Launch by
either Party within the meaning of Article 11 of the Agreement.


[***]     Filed separately with the Commission pursuant to a request for 
          confidential treatment.


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VIII.

This Side Letter constitutes an amendment to the Agreement within the meaning of
its Paragraph  20.6 and the terms of this Side Letter shall prevail in the event
of any  inconsistency  with the terms of the  Agreement.  This Side Letter shall
remain confidential and unless indicated expressly  otherwise,  authorization to
disclose the  Agreement  shall not include  authorization  to disclose this Side
Letter.


Executed this 8th day of January, 1998.


FOR ARIANESPACE                             FOR PANAMSAT CORPORATION


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