NASA Administrator Bill Nelson announced today that American astronauts Sunita Williams and Barry Wilmore will return next February with the SpaceX Crew-9 mission after spending more than 80 days aboard the International Space Station (ISS).
According to Steve Stich, NASA’s commercial crew program manager, “As we got more and more data over the summer and understood the uncertainty in that data, it became very clear to us that the best option was to return Starliner uncrewed.” He said NASA found “there was too much uncertainty in the thruster prediction.”
“If we had a way to actually predict what the thrusters would do, during undocking, throughout the deorbit process and during the separation sequence, I think we would have taken a different course of action. But when we looked at the data and looked at the potential for thruster failure with the crew on board… it was too much of a risk to the crew, so we decided to do the uncrewed test flight.”
In response to a question from reporters about how NASA can regain confidence in Boeing, NASA Associate Administrator Ken Bowersox said, “We’ve had a lot of tense discussions, haven’t we? Because the call was close and people have a lot of emotional stake in either option, and that gives you a healthy discourse. But after that, you have to do some work to keep your team together, don’t you?”
“And I recognize that we have work to do on that front. That's pretty natural when you have to make a difficult decision.” Bowersox said NASA remains “committed to working with Boeing.”
Stich chimed in, saying, “Boeing did a great job of creating a model. The question is, is that model good enough to predict the performance of a crew?” He later added, “There was a little bit of disagreement in terms of the level of risk. And that’s where it came down to, and I would say it’s close. It’s very close; it depends on how you assess the risk. We do it a little bit differently with our crew than Boeing did.”
With limited access to the spacecraft docked to the ISS, tests at NASA’s White Sands Test Center indicated that warped Teflon seals may have been one reason the spacecraft’s thrusters failed. But with no conclusive answers, NASA waited to decide whether to return the astronauts to Earth aboard the Starliner or work with SpaceX to bring them home early next year aboard the Crew-9 mission, scheduled to launch to the ISS in late September.
