After months of consideration, NASA said Thursday that it will finally decide the fate of two astronauts on board the International Space Station, Butch Wilmore and Suni Williams, by this weekend. As soon as Saturday, the two crew members will learn whether they'll return on a Starliner spacecraft in early September or a Crew Dragon vehicle next February.
On the eve of this fateful decision, the most consequential human spaceflight safety determination NASA has had to make in more than two decades, Ars has put together a summary of what we know, what we believe to be true, and what remains yet unknown.
Why has NASA taken so long?
Wilmore and Williams arrived at the International Space Station 11 weeks ago. Their mission was supposed to last eight days, but there was some expectation that they might stay a little longer. However, no one envisioned the crew remaining this long. That changed when, during Starliner's flight to the space station, five of the 28 small thrusters that guide Starliner failed. After some touch-and-go operations, the astronauts and flight controllers at Johnson Space Center coaxed the spacecraft to a safe docking at the station.
This failure in space led to months of testing, both on board the vehicle in space and with similar thrusters on the ground in New Mexico. This has been followed by extensive data reviews and modeling by engineers to try to understand the root cause of the thruster problems. On Friday, lower-level managers will meet in a Program Control Board to discuss their findings and make recommendations to senior managers. Those officials, with NASA Administrator Bill Nelson presiding, will make a final decision at a Flight Readiness Review on Saturday in Houston.
What are the two options?
NASA managers will decide whether to send the astronauts home on Starliner, possibly as early as September 2, or to fly back to Earth on a Crew Dragon vehicle scheduled to be launched on September 24. To make room for Butch Wilmore and Suni Williams, this so-called "Crew-9" mission would launch with two astronauts instead of a full complement of four. Wilmore and Williams would then join this mission for their six-month increment on board the space station—their eight-day stay becoming eight months.
How are Butch and Suni feeling about this?
We don't know, as they have not spoken to the media since it became apparent they could be in space for a long time. However, based on various sources, both of the crew members are taking it more or less in stride. They understand this is a test flight, and their training included the possibility of staying in space for an extended period of time if there were problems with Starliner.
That's not to say it's convenient. Both Wilmore and Williams have families back on Earth who expected them home by now, and the station was not set up for an extended stay. Wilmore, for example, has been having to sleep in a science laboratory rather than a designated sleeping area, so he has to pack up his personal things every morning.
What does seem clear is that Wilmore and Williams will accept NASA's decision this weekend. In other words, they're not going to stage a revolt in space. They trust NASA officials to make the right safety decision, whatever it ends up being. (So, for that matter, does Ars.)
Why is this a difficult decision?
First and foremost, NASA is concerned with getting its astronauts home safely. However, there are myriad other secondary decision factors, and bringing Butch and Suni home on Dragon instead of Starliner raises a host of new issues. Significantly among these is that it would be devastating for Boeing. Their public optics, should long-time rival SpaceX have to step in and "rescue" the crew from an "unsafe" Boeing vehicle, would be terrible. Moreover, the company has already lost $1.6 billion on the Starliner program, and there is the possibility that Boeing will shut it down. NASA does not want to lose a second provider of crew transport services to the space station.
So what will NASA officials discuss?
On Friday and Saturday, NASA engineers and decision-makers will review the final results of internal and external analyses of the failed thrusters. NASA wants to understand the root cause well enough to ensure there won't be multiple thruster failures on a return journey to Earth. The right combination of failures at the wrong time would be catastrophic for the crew.
However, the overall odds of a catastrophic failure are probably quite low. What is unique about this decision is that, for the first time when there have been serious questions about crew safety, NASA has a viable backup option to get Wilmore and Williams home. This is the Crew Dragon, which has now completed more than a dozen missions safely. No spaceflight is 100 percent safe, but NASA managers have confidence in the SpaceX vehicle.
The crux of the matter is this: How much risk is NASA willing to accept for Starliner? As an agency, NASA set a maximum acceptable risk of losing a crew at 1-in-270 for SpaceX and Boeing as part of this crew program. Are mission managers still holding that risk level? Are they willing to accept a higher risk at this point for Starliner's return? Can they even determine the loss-of-crew probabilities without understanding the root cause of Starliner's thruster problems? So far, space agency officials have not directly addressed this key risk question publicly.
Are there political considerations?
NASA has said data will guide its decision, and I have no reason to doubt that claim. However, the ultimate decision-makers have deep political ties. NASA Administrator Bill Nelson is a former US Senator from Florida, and he was appointed to his position by President Joe Biden. Nelson has told Ars he will have the final say in the decision chain this weekend.
Vice President Kamala Harris, who delivered a speech at the Democratic National Convention on Thursday night, is the titular head of the National Space Council, which guides US space policy. According to The Washington Post, she is receiving regular updates about the mission and is "closely following" its status.
I believe Nelson really will have the final say, and I don't think there will be much, if any, meddling from higher-level political officials. At the same time, Nelson cannot help but consider the political implications of NASA losing a crew a little more than two months before a consequential presidential election.
Are we putting too much blame on Boeing?
Boeing's position on Starliner has been clear for a while. The company is confident in its vehicle. At times, it has seemed like Boeing Starliner Program Manager Mark Nappi has been overconfident. As early as July 10, he said he expected that Starliner's thruster problems would be resolved "by the end of next week." Nappi has also chastised the media for suggesting that Starliner's crew might fly home in a different vehicle. As a reporter, it has become difficult to take Boeing's Starliner messaging at face value. Perhaps because of this, Nappi has been sidelined from NASA's last two Starliner media briefings.
Although Boeing deserves much of the blame for Starliner's troubles, there are other considerations. NASA's Commercial Crew program, for example, allowed this launch to occur after similar thruster problems occurred on the spacecraft's previous uncrewed test flight in 2022. Why did it allow this? And there is also Aerojet Rocketdyne. Boeing paid this propulsion firm a lot of money to develop what is, at least in terms of spaceflight, a relatively simple thruster. They are also responsible for this situation.
What are Boeing’s options if Starliner returns uncrewed?
Should NASA decide to fly Butch and Suni on Dragon, Starliner will be able to return autonomously to Earth thanks to a software update that has required a few weeks of work. Boeing and NASA would get a lot of useful data from such a flight. If all goes well, such a mission would probably leave a path open to certifying the vehicle for operational flights. If things go wrong, that could well mark the end of the Starliner program.
My sense is that, in the case of a successful autonomous undocking, NASA will work with Boeing to get Starliner flying. One option that has been mentioned is flying a cargo supply mission on Starliner, which would effectively allow NASA to "pay" for another uncrewed test flight of the vehicle. Publicly, NASA officials have not said whether a nominal autonomous return would clear the way for its crew to fly on Starliner's next mission. What does seem increasingly clear is that the next crewed Starliner mission probably won't happen before 2026.
What is happening with the Crew-9 astronauts?
This is another complication of sending Butch and Suni home on Crew Dragon—two of the four members of Crew-9 will get bumped. In January, the space agency formally announced a four-person crew that consisted of Commander Zena Cardman, Pilot Nick Hague, and Mission Specialist Stephanie Wilson, as well as Roscosmos cosmonaut and Mission Specialist Aleksandr Gorbunov.
If this vehicle is needed for a rescue mission, NASA has not publicly said who would be removed from the spacecraft. However, multiple sources have told Ars that Chief Astronaut Joe Acaba selected Cardman and Gorbunov to fly. He had little choice in keeping a Russian on the mission, as NASA and Roscosmos are committed to rotating US and Russian astronauts on the countries' respective spacecraft.
However, the selection of Cardman has raised some concerns in the crew office. The 36-year-old geobiologist is well-liked and highly regarded. But she has not flown to space before and is not a test pilot. (For that matter, Gorbunov is also a rookie without test pilot experience.) NASA has never sent a human mission to space without a test pilot or experienced astronaut in command. Some of the astronauts in the crew office have been pushing back on Acaba, saying that if just one NASA astronaut can fly on Crew-9, it is prudent to have the veteran Hague lead the mission. The decision of whether to fly Cardman or Hague alongside Gorbunov will probably be discussed on Friday and Saturday.
What is likely to happen?
For a long time, I was pretty confident that Butch and Suni would come back to Earth on Starliner. I trusted NASA and Boeing officials when they said they just needed to test the vehicle a bit more and become confident enough in the data and analysis to clear the crew to come home on the original spacecraft.
That started to change in late July. I began hearing from sources that the space agency was uncomfortable with some of the data it got from thruster hot fire tests in White Sands, New Mexico, earlier in the month. In reality, and in contrast with public statements, NASA had also been working with SpaceX for weeks on using Crew Dragon as a possible rescue vehicle. I reported this at the time. Based on this information, I believed it was slightly more likely than not that the crew would come home on Dragon.
Since then, I have heard much more about dissenting opinions from the crew office and other key areas within the space agency about a Starliner return. The question is whether NASA's final analysis convinces those dissenters to accept the unknown risks of flying on Starliner at Friday's Program Control Board meeting and then on Saturday during the Flight Readiness Review.
What I know for sure is that, internally at Johnson Space Center, teams have continued to work both return options, keeping open the possibility of Butch and Suni coming back on Starliner or Crew Dragon. I don't believe a final decision will be made until Saturday morning. However, as of Friday, my best information continues to point toward a Crew Dragon return as the most likely outcome.
