LAS CRUCES, N.M. — NASA expects to buy at least one more Soyuz seat from Russia to provide assured access to the International Space Station should commercial crew vehicles suffer additional delays.

In a media briefing after a visit to SpaceX headquarters in Hawthorne, California, Oct. 10, NASA Administrator Jim Bridenstine said NASA was in discussions with Roscosmos about ensuring NASA astronauts can remain on the station beyond the fall of 2020.

“We need to make sure that we do not have a day where don’t have American astronauts on the International Space Station, so we will be continuing to work with Roscosmos, which is the space agency of Russia, to ensure that we do have American astronauts on the International Space Station as an insurance policy” for commercial crew, he said.

NASA doesn’t expect to need any more Soyuz seats. At that briefing at SpaceX, Bridenstine said that the company’s Crew Dragon vehicle could be ready for a crewed test flight, known as Demo-2, as soon as the first quarter of 2020. The same day, NASA and Boeing officials at the International Symposium for Personal and Commercial Spaceflight (ISPCS) here said they expected Boeing’s CST-100 Starliner to be ready for a crewed test flight in the same time frame.

However, both vehicles have suffered extensive delays in their development and still have to perform key tests before NASA will be ready to fly astronauts on them. That could further delay their readiness, possibly until late next year.

“If everything goes according to plan, we may not need additional Soyuz seats,” Bridenstine said. “But here’s something else we know: usually things don’t go according to plan when it comes to these new development capabilities.”

In a talk earlier Oct. 10 at ISPCS, Ken Bowersox, acting associate administrator for human exploration and operations at NASA, said discussions were underway within the government about additional Soyuz seat purchases.

“We need to start earlier, so we’re discussing that with folks inside government in the U.S. and with our Russian partners, but we don’t have any agreements that are concluded yet,” he said. “It is likely that we’ll want to try and set up arrangements for at least one more seat on the Soyuz in the fall of 2020 to spring of 2021.”

He added that, even after commercial crew vehicles start flying, he expected American astronauts would continue to fly on Soyuz vehicles. The difference is that those seats would be bartered in exchange for flying Russian cosmonauts on commercial crew vehicles. Doing so, he said, makes it convenient for crew rotations and ensures that there would always be an American on the station.

Buying additional Soyuz seats may require more than just an agreement with Rosocosmos. At an Oct. 4 briefing at the Johnson Space Center, Kirk Shireman, NASA ISS program manager, noted that NASA’s existing waiver of sanctions imposed on Russia by the Iran, North Korea and Syria Nonproliferation Act (INKSNA) expires at the end of 2020. Congress would have to pass legislation, as it has done so in the past, to extend the waiver to allow additional purchases.

“Not only do we need a contract with Roscosmos, but we need literally an act of Congress,” he said.

Shireman said NASA will work to provide Boeing and SpaceX with as much schedule margin as possible so they are not rushed to complete their vehicles and jeopardize their safety. “We need them to fly but, more importantly, we need them to fly safely,” he said.