WASHINGTON — The Falcon 9 successfully launched a science mission to Earth for Europe and Japan on May 28 as part of the European Space Agency’s continued, albeit temporary, dependence on SpaceX for access to space.
Falcon 9 lifted off from Vandenberg Space Force Base in California at 6:20 p.m. ET. The payload, the Earth Cloud Aerosol and Radiation Explorer (EarthCARE) spacecraft, separated from the upper stage about 10 minutes after liftoff.
Simonetta Cheli, ESA’s director of Earth observation programs, said in an interview after launch that controllers were in contact with the spacecraft. “Everything is nominal and on track.
Spacecraft controllers spend weeks and months ahead checking the spacecraft’s instruments and calibrating them, she said. This will enable the first release of scientific data from EarthCARE later this year or early next year.
EarthCARE is an 800 million euro ($870 million) mission led by ESA to study clouds and aerosols in the atmosphere. The spacecraft carries four instruments, including a cloud profiling radar provided by Japan’s JAXA space agency at a cost of ¥8.3 billion ($53 million). JAXA named the spacecraft Hakuryu or “White Dragon” because of the spacecraft’s appearance.
The 2,200-kilogram probe, flying in a sun-synchronous orbit at an altitude of 393 kilometers, will collect data on clouds and aerosols in the atmosphere, along with images and measurements of reflected sunlight and radiated heat. This information will be used for atmospheric science, including climate and weather models.
“EarthCARE is here to study the effect of clouds and aerosols on the Earth’s thermal balance,” said Dirk Bernaerts, ESA’s EarthCARE project manager, at a May 21 pre-launch briefing. “It is very important to observe them all together in the same place at the same time. That’s unique about this spacecraft.”
Other spacecraft are making similar measurements, including NASA’s Plankton, Aerosol, Cloud, Ocean Ecosystem (PACE) probe launched in February. “The observational techniques are different,” he said. “We’re observing the same thing, but we’re observing slightly different aspects of clouds and aerosols.” He added that EarthCARE will use the PACE data to help calibrate and validate its observations.
EarthCARE took about two decades to develop and led to a cost increase that Cheli estimated at a pre-launch briefing at 30%. Maximilian Sauer, EarthCARE project manager at prime contractor Airbus, said several factors, including technical problems with the instruments and the impact of the pandemic, contributed to the delays and overruns.
One of the lessons learned from EarthCARE, Cheli said in a post-launch interview, was the need for “tight management” of the project, which she said suffered from problems coordinating work between agencies and companies. The mission also underlined the importance of strong support from member states in working to overcome the challenges, she added.
Another factor in EarthCARE’s delay was the change in launch vehicles. EarthCARE was originally designed for the Soyuz rocket, but ESA lost access to the vehicle after the Russian invasion of Ukraine. The mission was initially moved to Europe’s Vega C, but ESA decided last June to launch it instead on a Falcon 9, citing delays in that rocket’s return to flight as well as modifications to the rocket’s fairing that would be necessary to accommodate EarthCARE.
Technically, the displacement of the launch vehicles was not a critical problem for the mission. “During the changes in the launch vehicles, we didn’t have to change the design of the spacecraft,” Bernaerts said.
He said that during the environmental tests, engineers subjected the spacecraft to conditions simulating various launch vehicles to prepare for the potential of changing vehicles. “From the moment we knew the Soyuz was not available, we considered how rigorously we could test the spacecraft to envelope other candidate launch vehicles. That’s what we did, and it finally worked.”
EarthCARE is the second ESA-led mission to launch on Falcon 9, following the Euclid Space Telescope last July. Another Falcon 9 will launch an ESA mission to the asteroid Hera this fall.
“We had a good experience with Euclid last year,” said Josef Aschbacher, ESA’s director general, in a post-launch interview. “Our teams and the SpaceX teams are working very well together.”
Falcon 9 use is on hiatus until Ariane 6 enters service, with the first launch now scheduled for the first half of July and the Vega C returning to flight at the end of the year. “I’ve heard a lot of questions about why we’re launching with the Falcon and not the Ariane, and it’s really good to see the Ariane 6 launch getting closer,” he said.
Those involved in the mission were just happy to finally get the spacecraft into orbit. “There is a sense of relief and happiness,” said Cheli after the start.
“It’s an emotional rollercoaster,” Thorsten Fehr, ESA’s EarthCARE mission scientist, said in an agency webcast of the launch shortly after the payload separated. “This is one of the greatest moments in my professional life.