The Jason-1 ocean-observing satellite, a joint project of CNES and NASA, arrived at Vandenberg
Air Force Base, California, on 31 July to begin final integration and installation under the payload
fairing of a Delta II launch vehicle. Built in Cannes by prime contractor Alcatel Space Industries,
Jason-1 was flown to Vandenberg on an Antonov-124 cargo plane and then transported to a
clean room where teams are now preparing the satellite under CNES supervision before turning
it over to Boeing on August 22 in preparation for launch.

Jason-1 is the follow-on to Topex/Poseidon, the French-US satellite that has been making
precise measurements of ocean surface topography since being launched by Ariane in 1992,
and is still operating today. The exceptional quality of Topex/Poseidon data-yielding mean sea
level measurements accurate to one centimetre-have significantly improved our understanding
of the role oceans play in regulating global climate, and enhanced our ability to track rising sea
level, the carbon cycle and climatic events such as El Niño and La Niña. The quality of these
altimetric measurements is largely due to the French DORIS accurate location instrument, which
is also on the SPOT satellites.

The launch of Jason-1 marks an important milestone in the development and deployment of
future operational systems for ocean observation and forecasting applications. Building on the
lessons learned in designing the instruments and processing data for its prolific predecessor,
Jason-1 is set to provide sea level and sea state measurements with turnaround times of hours
to days for a growing international user community.

Jason-1 is the first satellite built around the new Proteus multimission spacecraft bus developed
in partnership by CNES and Alcatel Space Industries. Increased miniaturization of the
instruments, particularly the altimeter, has significantly reduced the satellite’s size and weight
(500 kilograms). As a result, development costs have been cut while offering the same level of
performance as Topex/Poseidon, if not better.

Jason-1 will be ready for launch no earlier than 15 September, at the start of a scheduled
ten-day launch period. The launch window is about 20 minutes each day, opening on 15
September at 9:59 a.m. French time and getting earlier by about 12 minutes each day. Once it
reaches its final orbit, Jason-1 will assume the same flight path as Topex/Poseidon, which will
move into a parallel orbit. The two satellites will circle Earth every 112 minutes at an altitude of
about 1,330 kilometres.

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