Ax-1 docking
The Ax-1 Crew Dragon spacecraft docked with the space station early April 9, a little more than 21 hours after launch from Florida. Credit: NASA TV

PARIS — NASA is requesting proposals for two private astronaut missions to the International Space Station in 2023 and 2024, enforcing a requirement such missions be commanded by former NASA astronauts.

NASA said Sept. 14 it was seeking proposals for the third and fourth private astronaut missions, or PAMs, to the space station, with the proposals due Oct. 27. One mission would fly between late 2023 and mid 2024, and the other in the second half of 2024, depending on overall ISS schedules.

The first PAM, the Ax-1 mission by Axiom Space, flew to the station in April. NASA selected Axiom last December for the second PAM, Ax-2, and finalized the agreement for that mission Aug. 31. Ax-2 is scheduled to launch in the second quarter of 2023 on a SpaceX Crew Dragon spacecraft.

As part of the agency’s broader low Earth commercialization strategy, NASA will allow up to two private missions to the ISS each year, each lasting up to two weeks, to help industry build up experience for future commercial space stations that will succeed the ISS.

“These provide a unique opportunity for industry to gain critical experience needed to select, train and manage crews on future commercial low-Earth orbit destinations, as well as work with new science partners, future commercial partners and grow this non-traditional market,” said Angela Hart, manager of NASA’s Commercial LEO Development program at the Johnson Space Center, in an agency statement.

NASA requested proposals for that third PAM opportunity last year at the same time as the second PAM. While NASA selected Axiom Space — the only company to submit a proposal — for the second PAM, it rejected proposals from Axiom and another company, Shuttle IO Technologies, for the third PAM after giving them poor ratings. NASA said at the time it would seek proposals for the third PAM at a later date after incorporating experience from initial missions.

The request for proposals also confirms NASA’s plans, disclosed in an Aug. 1 regulatory filing, that private astronaut missions be led by a former NASA astronaut. “A former NASA astronaut provides experienced guidance for the private astronauts during pre-flight preparation through mission execution,” NASA said in the filing, noting that, at the time, that requirement was still being finalized.

Companies responding to the PAM solicitation are required to provide up to 10 pages of information about the commander of the mission and that person’s experience. That includes being a “former NASA (U.S.) flown government astronaut” with experience in key technologies, operations and “maintaining a harmonious and cohesive relationship among crewmembers.” NASA also requires three references from previous supervisors or managers in the Flight Operations Directorate who know the proposed commander from their time at NASA.

NASA also noted in the procurement that proposed missions seeking to conduct a spacewalk by private astronauts “will not be considered allowable.” It’s unclear if any companies were actively considering spacewalks on private missions. Axiom Space, which won one of two spacesuit development awards from NASA announced in June, said at the time that it had customers interested in doing spacewalks, but didn’t say if those would be on PAM flights or the company’s later commercial space station.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...