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GRACE 2 (nick-named Jerry) is one of a pair of identical satellites. The acronym stands for Gravity Recovery and Climate Experiment. The primary goal of the mission is to obtain accurate global and high-resolution values of both the static and time-variable components of the Earth's gravitational field. This is achieved by measuring the relative distance between the pair, between 100-500 km, by means of K-band microwave sounding at an accuracy of few microns in conjunction with GPS fixes (by JPL Black Jack GPS Receivers) of their locations. The major perturbations due to air drag and solar radiation pressure will be accounted for by an accelerometer data.

The ranging instrument is named KBR (K-Band Ranging); the accelerometer, ACC is the ONERA SuperSTAR Accelerometer. Star Camera Assemblies (SCA) on each spacecraft will provide attitude data. Finally, a Laser Corner-Cube Reflector Assembly (LRA) mounted on the underside of each spacecraft will enable (redundantly) orbit verification.

Alternate Names

  • 27392
  • GRACE2
  • Gravity Recovery and Climate Experiment 2
  • Jerry
  • Tom and Jerry

Facts in Brief

Launch Date: 2002-03-17
Launch Vehicle: Rokot
Launch Site: Plesetsk, Russia
Mass: 500 kg
Nominal Power: 620 W


  • Earth Science

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office


Other Sources of GRACE Information/Data

GRACE project page (U. Texas-Austin)

GRACE page (GFZ Potsdam)

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