NASA climate mission blasts off from California on SpaceX Falcon 9 rocket

Aboard a used SpaceX Falcon 9 rocket, a NASA climate mission hitched a ride to orbit Tuesday from California alongside a batch of commercial satellites.

Less than 12 minutes after a 3:47 p.m. EDT blastoff from Vandenberg Air Force Base, twin sports car-sized spacecraft deployed to start the joint U.S.-German science mission that will measure water’s movement around the planet by detecting tiny changes in the pull of gravity.

Known as GRACE-FO, the mission is a follow-on to the partners’ Gravity Recovery and Climate Experiment mission, or GRACE, which concluded 15 years of measurements last year.

“We were able to see how water has moved from different parts of the Earth by actually measuring its mass, which is not something you would see with your eyes, it’s something you have to feel with a satellite system,” said Frank Webb, the project scientist from NASA’s Jet Propulsion Laboratory in Pasadena.

Union approves contract; strike of ULA ends

NASA exploring commercial space stations

The German Research Center for Geosciences provided the launch, securing the "rideshare" with five Iridium Communications satellites that deployed into higher orbits more than an hour after liftoff.

The two science spacecraft, each weighing about 1,300 pounds, will fly 305 miles up and 137 miles apart from each other.

With microwave beams and experimental laser instruments, the spacecraft will precisely measure the distance separating them, detecting changes less than the width of a human hair as features on the ground affect their gravity field.

That technique enabled the GRACE mission to measure significant losses in ice mass in Greenland and Antarctica, changes that contribute to sea level rise.

The findings in general will help scientists quantify how much sea level rise is due to more water flowing into oceans, versus heating causing water volume to expand.

GRACE also observed California drop water weight during a drought that led to more water being pumped from the aquifer.

The follow-on mission’s minimum five years of data, continuing the 15 years recorded by GRACE (with a one-year gap in between), will help scientists understand if such changes "are just short-term variability or longer-term trends related to our evolving climate,” said Webb.

NASA contributed $430 million to the follow-on mission, while Germany pitched in about $91 million.

For Iridium, the mission was the sixth of eight to be launched by SpaceX that have now placed 55 Iridium NEXT satellites in orbit, with 20 more to go this year.

The launch was SpaceX’s 10th of the year, re-flying the booster from the company’s first launch of 2018, of the U.S. government’s classified Zuma mission. It was the 12th time SpaceX has reused a flown booster, including the two on February's demonstration of the Falcon Heavy rocket.

The company did not try to land the booster, but continued attempts to catch the two halves of the rocket's nose cone with a ship as they fell to the Pacific Ocean under parachutes. This time, SpaceX said the ship was "close but not quite" able to make the catch.

SpaceX’s 11th mission of the year could come next week from Cape Canaveral Air Force Station. A previously flown Falcon 9 is targeting a liftoff from Launch Complex 40 no earlier than 12:29 a.m. May 31 with the SES-12 commercial communications satellite for Luxembourg-based operator SES.

Contact Dean at 321-242-3668 or jdean@floridatoday.com. And follow on Twitter at @flatoday_jdean and on Facebook at https://www.facebook.com/FlameTrench.

Support local journalism: Sign up for a special Memorial Day offer for new subscribers at floridatoday.com/subscribe