Soyuz MS-18 crew
Mark Vande Hei (left) said he was “super excited” when he found out he would fly to the ISS with Russian cosmonauts Oleg Novitsky (center) and Pyotr Dubrov next month. Credit: NASA

WASHINGTON — A NASA astronaut flying to the International Space Station in April could spend up to a year on the station, an extended stay that he said he was “enthusiastic” about.

NASA announced March 9 that Mark Vande Hei would fly on the Soyuz MS-18 mission to the space station, launching April 9. He will fly with Roscosmos cosmonauts Oleg Novitsky and Pyotr Dubrov.

In a typical mission scenario, the three would stay on the station for about six months, returning after the next crew arrives on Soyuz MS-19 in October. However, Roscosmos officials have discussed filming a movie on the station in October, sending up director Klim Shipenko and an actress to be selected during an ongoing competition on Soyuz MS-19 along with commander Anton Shkaplerov. Shipenko and the actress would return on Soyuz MS-18 with Novitsky, commander of that mission, requiring Dubrov and Vande Hei to stay on the station until as late as April 2022, when the next Soyuz crew rotation mission launches.

Vande Hei, in a call with reporters March 15, acknowledged he may stay on the station for longer than six months. “It all depends on whether those tourists go up on the spacecraft in the fall, because they would take my seat back,” he said.

He said he welcomes the chance for an extended stay on the ISS. “Honestly, for me it’s just an opportunity for a new life experience. I’ve never been in space longer than six months,” he said, a reference to his first mission to the ISS, which lasted from September 2017 through February 2018. “I’m really enthusiastic about it.”

That uncertain duration is not the only unusual aspect about the mission. NASA acquired the seat not by purchasing it directly from Roscosmos, as it has in the past, but instead through an exchange with commercial spaceflight company Axiom Space, which obtained the seat from Roscosmos in a deal the terms of which neither Roscosmos nor Axiom disclosed. Axiom will receive a seat on a NASA commercial crew mission to the ISS, likely in 2023, in exchange for the Soyuz seat.

Vande Hei said he was not involved in the negotiations for the seat. “I’m sure it was a very complicated, challenging thing to work out. I know a lot of effort went into making it happen,” he said. “I’m really happy it worked out the way it did, and I’m also very happy that I did not have to deal with all those details.”

Vande Hei started training last year as a backup to Kate Rubins, the NASA astronaut who flew to the station on the Soyuz MS-17 mission last October, then “flowed right into” training for Soyuz MS-18. “The only thing that was uncertain was whether or not I actually launch as a result of doing the training,” he said.

Roscosmos originally announced that Sergei Korsakov would accompany Novitsky and Dubrov on Soyuz MS-18. Vande Hei trained with those three for months, he said, knowing that only three of the four people would fly. “We were ready for whatever contingency,” he said.

Because of that uncertainty, he said he had been managing his expectations about whether he would launch. “I was trying not to get too emotional, too excited about the fact that I may be launching in April,” he said. “I only realized that I had been doing that when I felt super excited when it was actually finalized.”

Roscosmos went as far to make two versions of the Soyuz MS-18 mission patch, one with Vande Hei’s name — seen in February in photos of training activities by Novitsky and Dubrov — and one with Korsakov’s name. In a show of comradery, Vande Hei said he wore the version of the patch with Korsakov’s name while Korsakov wore the patch with Vande Hei’s name. “I will always consider him to be a part of our team,” he said of Korsakov.

Russian media reported that Roscosmos is considering assigning Korsakov to a future Crew Dragon mission once NASA and Roscosmos finalize an agreement about the exchange of seats between Soyuz and commercial crew vehicles.

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...