NASA still expects Boeing's Starliner to return astronauts from ISS, but notes SpaceX backup option

With NASA astronauts docked at the International Space Station far longer than planned, the agency's leadership on Wednesday acknowledged potential alternatives to Boeing's Starliner for returning the crew to Earth.

Still, the Boeing's spacecraft remains the primary option for returning crew, officials said.

Officials say Starliner capsule "Calypso" may return as soon as the end of this month from its extended ISS stay, pending results of testing a faulty propulsion system. Starliner has now been in space 36 days and counting as the agency and Boeing perform additional testing in New Mexico before clearing the spacecraft to return.

The mission is the first time Starliner is carrying people, flying NASA astronauts Butch Wilmore and Suni Williams.

NASA's Commercial Crew manager Steve Stich emphasized during a press conference that the first "option today is to return Butch and Suni on Starliner," adding, "we don't see any reason" currently to turn to the agency's other transportation option, which would be SpaceX's Crew Dragon, to bring back the astronauts.

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Stich — while acknowledging that a SpaceX capsule could be part of contingency plans in case Starliner were to return from the ISS empty — noted that NASA does not yet need to "make a decision as to whether we need to do anything different."

"Certainly we've dusted off a few of those things to look at relative to Starliner, just to be prepared in the event that we would have to use some of those kinds of things," Stich said.

"[But] there's really been no discussion with sending another Dragon to rescue the Starliner crew," Stich added later.

Boeing and NASA on July 3 began testing the