Launch date: December 7, 2001
Purpose: Measure sea surface heights
Jason 1 is an oceanography mission to monitor global ocean circulation,
study the ties between the oceans and atmosphere, improve global climate
forecasts and predictions, and monitor events such as El Niño conditions
and ocean eddies.
It is a follow-on to the Topex/Poseidon mission,
which has been measuring
ocean topography since 1992. Like its predecessor, Jason 1 is a joint
mission of the United States and France. These two satellites will provide
a unique global view of the oceans that is impossible to acquire using
traditional ship-based sampling.
Like Topex/Poseidon, Jason 1 will be able to measure the large and small
hills and valleys of the ocean's surface. These measurements of ocean
topography allow scientists to calculate the speed and direction of ocean
currents and monitor global ocean circulation.
The global ocean is Earth's primary storehouse of solar energy. Jason 1's
measurements of sea-surface height will reveal where this heat is stored,
how it moves around Earth by ocean currents, and how these processes affect
weather and climate.
Jason 1 has been designed to directly measure climate change through very
precise millimeter-per-year measurements of global sea-level changes.
The Jason 1 satellite, its altimeter instrument and a position-tracking
antenna have been built in France. The spacecraft will also carry a radiometer
instrument to measure water vapor, a Global Positioning System receiver and a
laser retroreflector array built in the United States. Jason 1 was launched in December 2001 from California's Vandenberg Air Force Base.
Weighing 500 kilograms (about 1,100 pounds), Jason 1 is one-fifth the size of
Topex/Poseidon. After launch, Jason 1 will fly in tandem with Topex/Poseidon,
doubling the science data return for as long as Topex/Poseidon remains in good
health. Jason 1 will then assume Topex/Poseidon's former flight path. The
mission is planned to last for five years.
For more information, see this
Topex/Poseidon - Jason 1 web page.