The first phase of a joint mission run by NASA and the German Research Centre for Geosciences—or GFZ—successfully detached from a SpaceX Falcon 9 rocket on May 22, releasing a pair of satellites that will now orbit the Earth for at least a half decade. The spacecraft launched just before 1 p.m. that day from Vandenberg Air Force Base, also carrying satellites from private company Iridium Communications.
Lead scientists and researchers with the project say the GRACE-FO (Gravity Recovery and Climate Experiment Follow-On) mission will provide critical measurements that will be used together with other data to monitor the movement of water masses across the planet and even changes of mass within the Earth itself.
“The GRACE-FO mission gives us a rich understanding of a fundamental resource on our [planet], which is water,” explained Sascha Burton, systems engineer at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, who spoke with the Sun the week leading up to the launch. She said the satellites would observe how water moves and changes on and beneath the Earth’s surface and help scientists better understand the climate.
“The type of research to be done with this mission is mostly related to climate and hydrology,” added Frank Webb, a GRACE-FO project scientist at JPL, on a conference call May 21 with media.
It’s been almost a year since NASA conducted its final measurements with the former GRACE system, Webb said. That iteration of the project operated for 15 years.
“GRACE was really a revolutionary mission for us in understanding the water cycle and how the climate behaves and the trends which are taking place in the last 10 or 15 years,” Webb said. “This was a view that we didn’t have before of water on the Earth. We were able to see how water had moved by actually measuring it with mass—that’s not something you see with your eyes.”
The newly launched twin satellite constellation that makes up the GRACE mission will observe changes in ice sheets, glaciers, global sea level, and underground water storage. That last piece is critical for places like California, which has seen significant subsidence in areas such as the Central Valley. Similar areas of subsidence can be found in Santa Barbara County, such as in the Cuyama Valley.
The drought over the past decade has clearly affected those areas, according to Webb. He said the original GRACE mission—completed in early 2017—observed significant water weight loss due to minimal rainfall and snowpack, coupled with excessive groundwater pumping from farmers on the Central Valley aquifer. Webb noted last year’s wet winter seemed to lessen some of the mass loss in water, but it remained to be seen what the long-term effects from the storms were, he said.
“We’ll have about a one year gap [in data] and we’ll see how much of that water actually stayed in the ground and went into the ground as opposed to running off into the ocean,” Webb added.
Accompanying the NASA and GFZ mission were five Iridium NEXT satellites. The company claims it is the only of its kind to offer “truly global voice and data communications coverage.” Iridium CEO Matt Desch told the Sun in March of this year that once their constellation of 66 satellites were all in orbit and operation the network would eventually allow for “100 percent global, real-time” ship and aircraft tracking. The May 22 launch was the sixth time the communications company partnered with SpaceX to place the satellites in Earth’s orbit.
This article appears in May 24-31, 2018.