Mission: Jason-3 Credit: NASA/JPL-Caltech When did Jason-3 launch? January 17, 2016 Where is Jason-3? 830 miles (1336 km) from Earth What does Jason-3 do? Jason-3 is the fourth U.S.-European satellite mission that measures ocean-surface height. Jason-3 will help us understand ocean circulation patterns, sea-level changes, and climate change. Learn more about NASA’s Jason-3.