Jason-3 update

The newly launched Jason-3 satellite moved into its final orbit Feb. 12, and is now trailing its counterpart, Jason 2, by only two minutes.

The two spacecraft, some 830 miles (1,336 kilometers) above Earth, will measure sea levels in virtually the same ocean conditions now that they are flying in formation—“just in time for Valentine’s Day,” says Josh Willis, NASA project scientist for Jason-3 at the Jet Propulsion Laboratory in Pasadena.

For the first six months, the measurements mainly will be used to calibrate Jason-3’s instruments by comparison to Jason-2, aloft since 2008.

After Jason-3’s checkout phase, full science operations begin.

Jason-3 will carry on the tradition of using satellite altimetry to gauge sea-surface height, begun in 1992 with Topex/Poseidon. Such measurements provide a wealth of data on ocean dynamics, including the speed and direction of ocean currents, as well as the heat content of the ocean itself, and, of course, global sea level rise—one of the most important indicators of human-caused global warming.

The same data also will be available to the broader scientific, commercial and maritime communities.