GRACE-FO Prelaunch Briefing

A photo showing the The twin GRACE-FO spacecraft installed on top of the five Iridium NEXT communications satellites is seen as experts discuss the Gravity Recovery and Climate Experiment Follow-On mission during a prelaunch media briefing, Monday, May 21, 2018, at Vandenberg Air Force Base in California. The twin GRACE-FO spacecraft will measure changes in how mass is redistributed within and among Earth's atmosphere, oceans, land and ice sheets, as well as within Earth itself. Photo Credit: (NASA/Bill Ingalls)