[G03-1] Current and future satellite gravity missions

[G03-1-01] Current Status of the GRACE Mission

^○Byron Tapley¹, Frank Flechtner², Michael Watkins³, Srinivas Bettadpur¹ (1.University fo Texas Center For Space Research, 2.German Research Centre for Geosciences - GFZ,, 3.NASA Jet Propulsion Laboratory)

invited

The twin satellites of the Gravity Recovery and Climate Experiment (GRACE) were launched on March 17, 2002 and have operated for over 15 years. The mission objectives are to sense the spatial and temporal variations of the Earth's mass through its effects on the gravity field at the GRACE satellite altitude. The major cause of the time varying mass is water motion and the GRACE mission has provided a continuous decade long measurement sequences which characterizes the seasonal cycle of mass transport between the oceans, land, cryosphere and atmosphere; its inter-annual variability; and the climate driven secular, or long period, mass transport signals. In 2012, a complete reanalysis of the mission data, referred to as the RL05 data release, was initiated. The monthly solutions from this effort were released in mid-2013 with the mean fields following in subsequent years. The mission is entering the final phases of operations with mission end expected to occur before July 1, 2017. The current mission operations strategy emphasizes extending the mission lifetime to minimize the break in the measurements before the GRACE Follow-On Mission is launched. This presentation will review the mission status and the projections for mission lifetime, describe the issues that influence the operations philosophy, discuss the approaches to bridge the gap between GRACE and GRACE FO and discuss the content of the science data products during this phase of the mission.