GRACE-FO First Light

The Gravity Recovery and Climate Experiment Follow-on (GRACE-FO) mission, launched on May 22, 2018 is a successor to the original 2002 GRACE mission, which monitored Earth's gravity by measuring the distance between two satllites following each other in orbit around Earth. In addition to carrying on the original series of measurements made by a microwave ranging system, the GRACE FO mission will test a new laser ranging interferometer, which will provide higher precision distance measurements.

These two images show the first data from the Microwave Ranging Instrument and the Laser Ranging Interferometer (LRI) instrument onboard GRACE FO. The raw data for both instruments is a plot of inter-spacecraft distance, which changes as the spacecraft pass over varying mass distribution caused by features on Earth such as large mountain ranges.

The Gravity Recovery and Climate Experiment Follow-on (GRACE-FO) mission is a partnership between NASA and the German Research Centre for Geosciences (GFZ).

See the following sources:

• https://www.jpl.nasa.gov/news/news.php?feature=7156
• https://www.nasa.gov/feature/jpl/first-laser-light-for-grace-follow-on
• https://gracefo.jpl.nasa.gov