A twin spacecraft to track the global water cycle has been successfully launched aboard the SpaceX rocket, along with five communications satellites on Wednesday, NASA said.
The Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) is a joint mission by NASA and the German Research Centre for Geosciences (GFZ).
It lifted off on a SpaceX Falcon 9 rocket from the Vandenberg Air Force Base in California, US, sharing their ride into space with five Iridium NEXT communications satellites.
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 about 490 kilometers, traveling about 7.5 kilometers per second. They are in a near-polar orbit, circling Earth once every 90 minutes.
“GRACE-FO will provide unique insights into how our complex planet operates,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate at NASA Headquarters in Washington.
Factfile on the twin satellites that comprise the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) mission to track Earth’s mass in motion. (AFP)
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 Earth’s 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.
The original GRACE mission, which operated from 2002 through 2017, created monthly maps of regional gravity variations, providing new insights into how the Earth system functions and response to change.
Among its innovations, GRACE was the first mission to measure the amount of ice being lost from the Greenland and Antarctic ice sheets.
The mission improved our understanding of the processes responsible for sea level rise and ocean circulation, provided insights into where global groundwater resources are shrinking or growing, showed where dry soils are contributing to drought and monitored changes in the solid Earth, such as from earthquakes.
The GRACE-FO satellites will spend their first few days in space moving to the separation distance needed to perform their mission. When they reach this distance, the mission will begin an 85-day, in-orbit checkout phase.
Mission managers will evaluate the instruments and satellite systems and perform calibration and alignment procedures. Then the satellites will begin gathering and processing science data.