The twin Gravity Recovery and Climate Experiment Follow-On, dubbed GRACE-FO, arrived Dec. 12 at Vandenberg’s airfield aboard a cargo plane that left Munich, Germany, on Dec. 11.
“With this milestone, we are now in position to launch GRACE Follow-On and restart the valuable observations and science that ceased in mid-2017 with the end of the GRACE science mission,” said Michael Watkins, director of NASA’s Jet Propulsion Laboratory in Pasadena and lead for the GRACE Follow-On science team.
The U.S./German spacecraft will undergo processing to get ready for launch in the spring aboard a Space Exploration Technologies Falcon 9 rocket from Space Launch Complex-4 on South Base.
The GRACE-FO craft will head to space aboard a rideshare mission — five Iridium Next satellites also will be tucked in the Falcon’s nosecone for the flight.
Iridium Next’s fourth mission launched Dec. 22 from the base at sunset, creating a dramatic spectacle many mistook for an unidentified flying object.
The GRACE twins will extend an Earth climate data record started by what scientists call an extremely successful predecessor during a pioneering mission.
The original GRACE completed its science mission in October after more than 15 years in orbit following an age-related battery issue involving GRACE-2, NASA officials said. Both satellites must operate for the science mission to occur.
While similar to their predecessor GRACE satellites, the new spacecraft include advancements designed to improve reliability and mission operations, officials said.
Once in orbit and operational, GRACE-FO, which is designed to operate for at least five years, will continue to track differences in the distribution of liquid water, ice and land masses by measuring changes in Earth’s gravity field every 30 days.
The GRACE mission has delivered “paradigm-shifting insights” into the interactions of Earth’s oceans, atmosphere and lands, according to Byron Tapley, GRACE principal investigator from the University of Texas at Austin