PARIS — The Jason-1 U.S.-French ocean-altimetry satellite, launched in December 2001 on a three-year mission, has been shut down after an 11.5-year service life, NASA and the French space agency, CNES, announced July 3.
The Jason satellite series and its predecessor, the U.S.-French Topex-Poseidon satellite launched in 1992, have created an operational service that U.S. and European civil and military officials say has more than demonstrated its usefulness.
But the series has nonetheless struggled with funding issues and has delivered an uninterrupted flow of ocean-height and other data only because the satellites have been more robust than originally planned.
Topex-Poseidon was retired in 2006, 13 years after launch. Jason-1 was supposed to operate only until 2004, or 2006 at the latest. Delays in the financing of its Jason-2 successor prevented the second Jason from launching until 2008.
Jason-2 remains operational and its users can only hope it remains healthy enough to deliver data until the planned 2014 launch of Jason-3. A Jason-4 also is being planned by the European Space Agency.
Jason-1’s orbit was lowered by 12.6 kilometers, to 1,323.4 kilometers, in 2012 following an on-board failure. The new orbit was considered low enough to permit the satellite to end its life there and still respect international guidelines calling for low-orbiting satellites to re-enter Earth’s atmosphere within 25 years of being retired to prevent them from adding to orbital debris.