Boeing's CST-100 Starliner vehicle's crewed test flight might cause a temporary issue in the plans to exchange seats between commercial crew vehicles and Soyuz spacecraft to the International Space Station, even if it is successful.
During a briefing on May 3 at Kennedy Space Center, officials from NASA and Boeing announced that the launch readiness review for Starliner's Crew Flight Test (CFT) mission has been completed. The mission is scheduled to launch no earlier than 10:34 p.m. Eastern May 6 on a United Launch Alliance Atlas 5. There were no issues with the spacecraft, and the weather forecast indicated a 95% chance of acceptable launch conditions.
The CFT mission is meant to be the final test flight for Starliner before NASA approves it for use on crew rotation missions to the ISS. NASA astronauts Butch Wilmore and Suni Williams will conduct the mission, which is expected to last a little over a week.
Steve Stich, NASA commercial crew program manager, expressed excitement at the briefing, stating, "It's exciting to bring in Starliner and the ULA Atlas 5. We've been aiming for commercial crew to have two independent space transportation systems. That's been our goal from commercial crew's inception and we're very close to reaching that goal.
If the CFT mission is successful, NASA would be able to certify the vehicle in time for an early 2025 launch of the first operational Starliner mission, designated as Starliner-1. NASA has already announced three of the crew members for that flight: NASA astronauts Scott Tingle and Mike Fincke, and Canadian Space Agency astronaut Joshua Kutryk.
The fourth person to fly on that mission has not yet been assigned. NASA stated in November that the final crew assignment for Starliner-1 will be announced following review and approval by the agency and its international partners when it announced the addition of Kutryk to the crew.
Since the fall of 2022, one seat on commercial crew missions has been assigned to a Russian cosmonaut, as part of a seat barter agreement that was finalized in July 2022 between NASA and Roscosmos. In exchange, a NASA astronaut gets a seat on Soyuz flights to the station, an approach NASA calls "integrated crews" that ensures there will be at least one American and one Russian on the ISS in case either Soyuz or commercial crew vehicles encounter problems.However, at the May 3 briefing, NASA officials stated that it was unlikely for a Russian cosmonaut to be assigned to Starliner-1. Dana Weigel, NASA ISS program manager, said, "We expect, on the Roscosmos side, they're more likely to want to see a long-duration flight also, so we think they'll want to start to fly with us on Starliner-2."
This possible decision could disrupt the ongoing series of seat exchanges between NASA and Roscosmos. "We're still working through that with our Roscosmos counterparts. It's our desire to continue to do integrated crew," she said, adding that NASA and Roscosmos don't have an agreement yet in place for exchanging crews in the timeframe that will include Starliner-1.
She said that any temporary gaps in mixed crews would only be for a short time. She also mentioned that the plan is to go back to mixed crews and swapping for all the other flights if they can't make the swap work.
After Starliner is approved, NASA intends to switch between that spacecraft and Crew Dragon for ISS crew rotation missions. Boeing has a contract for six operational missions, which, following that alternating flight approach, would extend until 2030, the planned retirement of the station.
Even if Boeing's CST-100 Starliner vehicle has a successful test flight with a crew, it could briefly disrupt the plans to switch seats between commercial crew vehicles and Soyuz spacecraft traveling to the International Space Station.