The Gravity Recovery and Climate Experiment, or Grace, consists of two spacecraft flying in tandem to measure Earth's gravitational field very precisely. These measurements enable a better understanding of ocean surface currents and ocean heat transport. The mission is able to measure changes in sea-floor pressure and show how the mass of the oceans change. It will also measures and monitors ice sheets and changes in the storage of water and snow on the continents.
Under the joint U.S.-German mission, JPL is providing mission design and instrumentation.
Purpose: Measure Earth's gravitational field with high precision