TOKYO — NASA officials say there is a “strong chance” that the next test flight of Boeing’s CST-100 Starliner commercial crew vehicle will be uncrewed as work continues to fix issues with the spacecraft.
At a July 10 briefing about the upcoming SpaceX Crew-11 mission to the International Space Station, Steve Stich, NASA commercial crew program manager, said the agency had yet to decide on plans for the next Starliner test flight after the problems experienced on the Crew Flight Test mission last year.
“We really are working toward a flight as soon as early next year,” he said of Starliner. “Ultimately, our goal is to get into crew rotation flights with Starliner and those would start no earlier than the second rotation slot at the end of next year.”
He indicated, though, that the test flight early next year, designed to confirm fixes currently being tested for helium leaks and thermal issues with the vehicle’s thrusters and their “doghouse” enclosures, would likely be one carrying only cargo and not astronauts.
“We’re still looking at that, whether it will be a cargo flight or not. I think there’s a lot of advantages, I would say, to flying a cargo flight,” he said, citing the experience SpaceX gained with cargo Dragon missions before starting Crew Dragon missions. “Can we test all the changes that we are making to the doghouses, in particular, on the ground, and would we want to validate those in flight first?”
“There’s a strong chance we’ll fly a cargo flight first,” he concluded. “We still haven’t made that decision yet.”
The ongoing work with Starliner involves tests of new materials that may be used in seals to prevent helium leaks. Separately, a Starliner thruster is undergoing tests at a NASA facility in White Sands, New Mexico, seeing how the duration and frequency of thruster pulses affect its performance.
That will lead to what he called an “integrated doghouse test” as soon as next month to test performance when multiple thrusters in the same enclosure are fired together. “We’re making a lot of progress in understanding the thermal performance,” he said, including modifications to draw heat away from the thrusters.
Stretching out ISS flights
The comments about Starliner were in a briefing about the Crew-11 mission, scheduled to launch to the International Space Station no earlier than July 31. It will deliver a new crew of four from NASA, the Japanese space agency JAXA and Roscosmos, relieving the Crew-10 that has been on the ISS since March.
An open question, though, is how long Crew-11 will remain on the station. In May, NASA said it was considering both reducing the crew size of future missions from four people to three and extending flight durations from six months to eight, citing “multi-year” budget shortfalls exacerbated by proposed cuts in NASA’s fiscal year 2026 budget request.
Stich said NASA was still working with SpaceX on certifying Crew Dragon for longer stays at the station. The spacecraft is currently approved to remain at the station for 210 days.
“We have started that work with SpaceX,” he said, but noted the current focus has been on certifying each Dragon to perform as many as 15 flights. The Dragon assigned to Crew-11, Endeavour, will be making its sixth flight.
A decision on extending Crew-11 from a baseline of six months to eight months could happen after the launch, he indicated, as SpaceX delivers and NASA evaluates the data needed for that assessment.
“When we launch, we have a six-month mission duration that we’ve baselined,” he said. “We can extend the mission in real time as needed.”
Ken Bowersox, NASA associate administrator for space operations, said on the call that the agency was evaluating the additional funding for ISS operations included in the budget reconciliation bill passed last week. That bill included $1.25 billion over five years for ISS operations that was intended to offset proposed cuts.
“We’re still evaluating how that’s going to affect operations going forward, but it’s a positive step,” he said.
Extending ISS missions to eight months, and thus reducing the cadence of such missions, would likely mean that there will be crew rotation flights under contract but not flown by the projected 2030 retirement of the station. Stich said it was “too early to speculate” how many Crew Dragon and Starliner missions will ultimately fly.
One option, he said, is that missions not flown by the retirement of the ISS could instead be used for missions to future commercial space stations. “Right now we’re taking it one step at a time, and the first step in front of us is Crew-11.”