NASA has launched two identical satellites into space from Californias coast with the aim of better managing Earths water resources. The joint US/German space mission was successfully launched at 12:47 p.m. PDT Tuesday from Vandenberg Air Force Base. The twin spacecraft of the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO), a joint NASA/German Research Centre for Geosciences (GFZ) mission, lifted off on a SpaceX Falcon 9 rocket, sharing their ride into space with five Iridium NEXT communications satellites. The satellites will measure the monthly changes in the oceans water content and the size of the ice caps to determine how climate change is affecting the planet. “Water resources are vital to life on Earth and the way we operate civilization,” says Frank Webb, GRACE-FO project scientist at NASA’s Jet Propulsion Laboratory. “It’s very important to understand how those resources are changing.” Ground stations have acquired signals from both GRACE-FO spacecraft. Initial telemetry shows the satellites are performing as expected. The GRACE-FO satellites are at an altitude of about490 kilometers, traveling about 7.5 kilometers per second. They are in a near-polar orbit, circling Earth once every 90 minutes. Over its five-year mission, GRACE-FO will monitor the movement of mass around our planet by measuring where and how the moving mass changes Earths gravitational pull. The gravity changes cause the distance between the two satellites to vary slightly. Although the two satellites orbit 220 kilometers apart, advanced instruments continuously measure their separation to within the width of a human red blood cell. NASA is scheduled to publicly release the first data collected by the satellites in 180 days, but the information provided by them will be analyzed by scientists every 30 days The two Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) satellites will allow scientists to produce monthly maps of water distribution and climate shifts, among other things. Tuesdays launch was the second phase of the GRACE mission, which was originally sent into space in 2002 and marked 15 years of space exploration last year. GRACE measured the loss of ice in Antarctica, identified patterns in changing ocean levels, discovered anomalies in the storage of underground water and monitored the California drought from 2011-2017. The data collected were "very important" for the scientific community, resulting in more than 30,000 publications and constituting the first steps toward improving global water management.