A joint satellite mission between NASA and the Centre National d’Études Spatiales (CNES) of France, launched on 20 June 2008 into the same polar orbit as Jason-1, inclined at 66° to the equator. It complements Jason-1, continuing the work started by TOPEX/Poseidon.

http://www.nasa.gov/mission_pages/ostm/main/index.html A joint CNES and NASA mission to study ocean current direction and to measure variations in sea surface height.