NASA is requiring employees involved in Artemis missions with contractors SpaceX and Blue Origin to stay on the job during the government shutdown, CNBC has learned.

Their work will be unpaid during the shutdown furlough, but employees should record their time, NASA Chief Human Capital Officer Kelly Elliott wrote in an email to staffers on Wednesday. NASA employees are expected to receive pay for their work after a reopening.

In a separate memo from Monday, NASA’s acting finance chief, Steve Shinn, laid out details about missions that would be supported during a shutdown.

NASA will continue to support “planned operations” of the International Space Station, as well as any satellite mission that “is in the operations phase,” Shinn wrote. He added that NASA would support “Artemis operations during any funding lapse,” including employees and contractors working on those projects.

Shinn said NASA would furlough around 15,000 people and require around 3,000 staffers to keep working, part time or full time, during the shutdown.

The U.S. government’s shutdown began early Wednesday morning, setting the stage for the furlough of hundreds of thousands of federal workers and the closing of a number of key programs and services. Government employees who are considered “essential,” like Transportation Security Administration (TSA) officers and air traffic controllers, are required to continue working.

On its website, NASA describes Artemis as a campaign to “send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.” The memos this week didn’t name the contractors associated with the various Artemis missions.

SpaceX, which is helmed by Elon Musk, won major Artemis contracts with its Starship rocket, the tallest and most powerful rocket ever launched. SpaceX has flown its full Starship rocket system on 10 test flights since April 2023, and plans to conduct another on Oct. 13. Its prior Starship test flights included five failures, a partial failure and four successes.

Blue Origin, owned by Amazon founder Jeff Bezos, was given another Artemis contract, and work on its lunar lander will also continue during the shutdown, NASA employees told CNBC.

Artemis III, scheduled for 2027, will be the first to involve SpaceX directly. The mission would land two NASA astronauts on the south polar region of the Moon.

Early Artemis missions involved NASA working with Lockheed Martin and Boeing to design, build, analyze and then buy rockets that the agency would own outright. With Artemis II, which is scheduled for early 2026, NASA aims to send four astronauts around the moon without landing before returning to Earth.

And the goal of Artemis IV+ HLS, with SpaceX, is to put astronauts into the first lunar space station, helping NASA and its partners to prepare for an eventual human mission to Mars. Artemis V is expected to involve Blue Origin.

Neither SpaceX nor Blue Origin has finalized the design of their lunar landers, and so far have only built test hardware.

Representatives of NASA, SpaceX and Blue Origin didn’t immediately respond to a request for comment. An autoreply from NASA said the agency “is closed due to a lapse in government funding.”

“I am in furlough status; therefore, I am unable to respond to your message at this time,” said the message from Cheryl Warner, news chief in NASA’s communications office.

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