Jason 1's oceanography mission to monitor global climate interactions between the sea and atmosphere reached another major milestone this past week with the successful handover of day-to-day operations from the French Centre National d'Etudes Spatiales to NASA's Jet Propulsion Laboratory, Pasadena, Calif.

With the handover, JPL is now responsible for around-the-clock real-time monitoring of Jason 1's health and status, and for generating and uploading weekly stored command sequences to the spacecraft. These sequences contain data for mission planning, payload commanding, navigation, ground station acquisition and routine maintenance functions.

The French Space Agency's Satellite Control Center in Toulouse, France, will continue to perform spacecraft engineering and navigation tasks. Both organizations will be jointly responsible for processing mission science data.

"Jason's measurement performance to date has been excellent," said Dr. Lee-Lueng Fu, Jason project scientist at JPL. "The early mission phases have been very smooth. This success is due in large part to the hard work and outstanding cooperation between the U.S. and French teams, who continue to work together to leverage experience and efficiencies gleaned from a decade of joint Topex/Poseidon operations. We look forward to continuing to work with the French to establish routine mission operations."

Much like its Topex/Poseidon predecessor, the Jason program's shared operations management approach is designed to maximize efficiencies and make the most of the two space agencies' differing program roles and expertise. The French Space Agency managed Jason 1 satellite development, engineering and delivery from the French aerospace company Alcatel, so the program's early post-launch checkout phases were conducted by the French. NASA, by contrast, is responsible for two of the mission's three ground tracking stations in Wallops Island, Va., and Poker Flats, Alaska, (the other is in Aussaguel, France), so JPL has responsibility for oversight of day-to-day routine mission operations.

During the next six months, Jason science data will be distributed to the mission's science team, and work will begin to conduct a precise scientific assessment of product quality through cross-calibration of Jason products with those of Topex/Poseidon. A science working team meeting will be conducted at the end of this six-month validation phase in October to verify that Jason data are accurate, correctly calculated and meeting program requirements. Science data products will then become available to the public.

Launched December 7, 2001, from Vandenberg Air Force Base, Calif., Jason's scheduled five-year mission will continue Topex/Poseidon's observations of ocean surface topography for monitoring world ocean circulation, studying interactions of the oceans and atmosphere, improving climate predictions and observing events like El NiŅo.

JPL, a division of the California Institute of Technology in Pasadena, manages the U.S. portion of the Jason mission for NASA's Office of Earth Science, Washington, D.C.