Peggy Whitson, one of NASA’s most experienced retired astronauts, is going back to space — this time with a racecar driver and two other passengers in the latest mission planned by Axiom Space. The Houston-based space company announced on Tuesday that Whitson will serve as the mission commander for its second private flight to the International Space Station, with John Shoffner, a GT racer, serving as mission pilot.

The Ax-2 mission with Whitson and Shoffner will be similar to Ax-1, Axiom’s first planned flight for early next year: a crew of four private citizens will fly to the International Space Station for a roughly eight-day stay conducting scientific research. It’s the latest private spaceflight planned so far as companies like SpaceX, Blue Origin, and Virgin Galactic race to offer tourists a trip to space — either to the ISS, orbit, or the edge of space.

Axiom serves as a mission manager that procures other companies’ spacecraft to fly people to space, charging passengers somewhere around $55 million per mission if it’s on SpaceX’s Crew Dragon capsule and probably more if it’s on Boeing’s Starliner capsule, which has yet to be flight-certified by NASA.

Whitson, 61, has tallied 665 days in space across three missions, the most for any NASA astronaut. She and Shoffner have been training as backups for Ax-1, which is slated to launch three entrepreneurs and former NASA astronaut Michael López-Alegría to the ISS in January 2022. That flight will use SpaceX’s Crew Dragon capsule, which has flown three crews of government astronauts to the ISS since May last year under NASA’s Commercial Crew Program. The ride for Ax-2 hasn’t been confirmed yet, Axiom says, and the two other Ax-2 crewmates are still being sorted out.

Photo: Axiom Space

When Whitson retired from NASA in 2018, she didn’t think she’d go back to space again. “I didn’t think it was likely. Probably because of that, I was more excited to be assigned as an Axiom backup for Ax-1 and then prime commander for Ax-2 than even for my first spaceflight,” she told The Verge in a phone interview. “It seemed even more unexpected.”

Shoffner, 65, is a trained pilot, investor in the life sciences industry, and a racecar driver who started a GT3 motorsports racing team named J2-Racing with his wife. He and Whitson will do research on the ISS for 10x Genomics, a California-based biotechnology company that manufactures gene sequencing technology for researchers. Shoffner, an investor 10x Genomics, plans to test single-cell sequencing methods while in microgravity, a first for the company.

“I’m going to try and help because I’m a geek. I like this stuff, too,” says Whitson, who holds a doctorate in biochemistry from Rice University and was once the deputy division chief for the Medical Sciences Division at Johnson Space Center, NASA’s astronaut headquarters in Houston.

Axiom says its private missions will launch every six months, meaning Ax-2 would launch in the middle of 2022 (or roughly half a year after Ax-1 in January 2022). But the date for Ax-2 depends largely on traffic at the space station, which only has two international docking adapters that serve as parking spaces for both cargo and government astronaut missions. Axiom will have to squeeze into the station’s increasingly busy schedule and reserve one of those adapters for the 10-day trip, including eight days docked to the ISS.

Earlier this month, NASA signed an agreement with Axiom to greenlight the company’s Ax-1 mission. The Ax-1 crew is still going through a rigorous training process intended to adjust crew members to the G forces of launching to space.

While its crew members will have to go through the same training, the Ax-2 mission is likely to be more costly than Ax-1. NASA has shifted the prices for hosting private astronaut missions on the space station, primarily a government-run research platform. Axiom’s second mission will be subject to the agency’s latest pricing table: a base of $5.2 million per person, and $4.8 million per mission to pay for planning and integration. The day rate for each passenger is anywhere between $88,000 and $164,000 to accommodate food, cargo, and other services. Axiom says it sorts this out with NASA and includes all of these charges in the customer’s single ticket price.

Axiom, founded in 2016 by a veteran NASA ISS program manager, is building its own private space station modules that it plans to attach to the ISS as soon as 2024. Whitson says her mission will help open doors for more ambitious crewed missions into space. “The future of spaceflight depends on us building an infrastructure that enables us to step further and further away from Earth,” she says. “This step by Axiom, introducing private astronauts to the space station, is going to be just the initial step.”