Boeing's two Starliner astronauts may learn their fate in the next two weeks — but, for now, NASA still doesn't know when the duo is coming home. So, while the space agency's best and brightest works with Boeing engineers to continue assessing data from ground tests of Starliner's systems, the spacecraft's crew, NASA astronauts Butch Wilmore and Sunita Williams, will remain aboard the International Space Station (ISS) for now.
Wilmore and Williams launched to the ISS aboard Starliner for the spacecraft's Crew Flight Test (CFT) on June 5. Their mission, to complete the first crewed shakedown cruise of Boeing's commercial crew vehicle, was initially only intended to last about 10 days, but now may be extended up to eight months, putting a potential return date in 2025.
Though initially delayed due to a minor helium leak, Starliner's ride to orbit went over without incident. However, as the spacecraft approached the ISS during docking, it experienced malfunctions in five of its 28 reaction control thrusters. As a result, NASA and Boeing extended the Starliner astronauts' stay aboard the space station indefinitely, while teams on the ground work to better understand what went wrong. Now, NASA officials say they expect to make a final decision on the crew's return by the last week of August.
NASA indicated in a previous update that it would be inviting additional propulsion experts to further assess Starliner's problems, which officials confirmed during a call with reporters Wednesday afternoon (Aug. 14).
"We brought in folks from the robotic spaceflight community at Glenn [Research Center] and at the Goddard Space Flight Center, at JPL. They're used to analyzing propulsion systems when spacecraft are millions of miles away, and they provided some useful input to us," said Ken Bowersox, associate administrator for NASA's Space Operations Mission Directorate, during the briefing.
Emily Nelson, Chief Flight Director for NASA's Flight Operations Directorate, stressed during the briefing the importance of adding "experts who have a totally different perspective to come in and look at the data that we've pulled together, as we try to understand what it is we may not understand."
As those experts continue to scrutinize Starliner's thruster data, NASA has also lined up some contingency plans. In the event of an emergency aboard the ISS, Wilmore and Williams are currently cleared to use Starliner to evacuate the space station — but beyond that, NASA isn't comfortable enough to give the spacecraft the greenlight to return to Earth.
Starliner's delayed departure from the space station has forced NASA to shift other upcoming flights destined for the orbital lab. SpaceX's Crew-9 launch, originally slated for this month, will now launch in late September, and an upcoming SpaceX Cargo Dragon resupply flight for NASA has been pushed back to mid-October. To prevent a traffic jam of incoming spacecraft, Starliner has to undock from the station before Crew-9's arrival — whether it carries a crew or not.
In the case of "or not," NASA is prepared to launch the Crew-9 mission with only two astronauts (or cosmonauts) aboard, ultimately folding Wilmore and Williams into Expedition 71 and 72 as official crew members. In this case, Starliner would undock from the space station with its cabin empty, perform a deorbit burn and reentry without Wilmore and Williams on board, and hopefully undergo a nominal parachute deployment, landing and recovery. The two astronauts would be given new seat assignments aboard the Crew-9 Dragon, and return to Earth at the end of that mission's rotation, sometime around February 2025.
"It's a fairly major discussion to decide about whether or not we're going to have crew onboard Starliner for return," Bowersox said during Wednesday's call. "The main thing we're looking at is the propulsion system."
"Our big concern is having a successful deorbit burn, making sure that the [propellant] system works just the way it needs to, all the way through the deorbit burn," Bowersox added.
NASA plans to conduct a flight readiness review following the completion of some key data analysis, which may begin as soon as next week. In the meantime, the Starliner astronauts patiently await a final decision.
Already aboard the ISS several weeks longer than they expected, Wilmore and Williams have been lending a hand where they can to help with regular station tasks, and seem to be enjoying their extra time on orbit, according to NASA's chief astronaut Joe Acaba.
"Right now, the agency has taken the time to ensure we are not putting the crew at a higher risk than is necessary," Acaba said during Wednesday's briefing. "As astronauts, that's always something worth waiting for."
