Atrists concept showing Jason-1 groundtrack.
Artists concept of Jason-1 ground track.

Image credit: NASA/JPL-Caltech
The Jason-1 spacecraft will make its 30,000th science orbit this week. Revolution number 30,000 will begin at 10:27 UTC (3:27 a.m. PDT) on June 14th, 2008 and will be completed at 12:19 UTC (5:19 a.m. PDT). From its vantage point 1,336 kilometers (830 miles) above Earth, Jason-1 uses its radar altimeter to precisely measure the topography of the ocean surface.

Jason-1 was launched December 7, 2001, as the follow-on to TOPEX/Poseidon, which successfully collected science data from 1992 to 2005. Both missions are a partnership between NASA and the French space agency, CNES. Covering 95% of Earth's ice-free ocean every 10 days, Jason-1 continues the critical data record of ocean surface topography, increasing our understanding of ocean circulation and the oceans' role in climate.

The data record of sea level from space will be continued into the next decade with the launch of the Ocean Surface Topography Mission on the Jason-2 satellite (OSTM/Jason-2), scheduled for June 20 from Vandenberg Air Force Base in California. Following spacecraft and instrument checkout and orbit maneuvers, OSTM/Jason-2 will operate in a tandem mode with Jason-1, providing a more detailed look at smaller-scale ocean phenomena and increasing global coverage by two-fold.

For OSTM/Jason-2, NOAA and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) join NASA and CNES in partnership. These two operational agencies will move radar altimetry from a research tool to a mature technology with everyday uses to benefit society.

Congratulations to the Jason-1 team on reaching this important milestone and best wishes for continued contributions to Earth science.