Gravity Recovery and Climate Experiment-Follow-On (GRACE-FO) Mission

The Gravity Recovery and Climate Experiment-Follow-On (GRACE-FO) Mission, due for launch early 2018, is a NASA directed mission to continue the goals of the original GRACE mission and provide continuity for the GRACE data set.

The primary goal of the GRACE-FO Mission is to obtain accurate global and high-resolution models for both the static and the time variable components of the Earth's gravity field. As in the original GRACE mission, this goal is achieved by making accurate measurements of the inter-satellite range between two co-planar, low altitude polar orbiting twin satellites using a K/Ka-Band microwave tracking system. Additionally, each satellite carries geodetic quality Global Navigation Satellite System (GNSS) receivers, a Laser Retro-Reflector (LRR) for ground station ranging, and high accuracy accelerometers to precisely measure the non-gravitational accelerations acting on the satellite.

As a secondary goal, GRACE-FO will carry a Laser Ranging Interferometer (LRI) as a technology demonstration. It will provide laser interferometry measurements of inter-satellite range changes in orbit to demonstrate laser-ranging technology in support of future GRACE-like missions. Another secondary objective is the continuation of GRACE radio occultation measurements.

The GRACE-FO project will be executed in the US under the direction of the NASA Earth Science Division (ESD) within the NASA Science Mission Directorate (SMD) and the Earth Systematic Missions Program Office at Goddard Space Flight Center (GSFC). The Jet Propulsion Laboratory (JPL) is assigned responsibility for the GRACE-FO project.

The GRACE-FO mission has significant German participation managed by the German Research Centre for Geosciences (GFZ). Funding of the German contributions is jointly secured by the Federal Ministry of Education and Research (BMBF), the Federal Ministry for Economic Affairs and Energy (BMWi), the Helmholtz Association (HGF), the German Aerospace Center (DLR) (LRI in kind contributions) and the German Research Centre for Geosciences (GFZ).

The overall agreement between NASA and GFZ will be codified in a Memorandum of Understanding (MOU), the roles and responsibilities are described in a Cooperative Project Plan (CPP). According to that GFZ will be responsible for 

  • Science data exploitation and dissemination within the joint US/German Science Data System (SDS) including release of product versions of the GRACE-FO science data products through their Information System and Data Center (ISDC),
  • Provision of developments for the Experimental Laser Ranging Interferometer (LRI),
  • Provision of a Launch vehicle and launch services,
  • Provision of Laser Retro-Reflectors (LRR) for each spacecraft,
  • Mission operation (with US-support) and
  • Leading the European Science Team.

Details on the various mission elements, recent news or related publications are described in the corresponding links beside.