As NASA and Boeing focus on completing the first astronaut mission aboard the Starliner spacecraft early next month, everyone is already thinking about what will happen next.
Boeing's Starliner capsule was delayed again Friday (June 21) from completing its first mission at the International Space Station (ISS) with astronauts, with crew including NASA's Butch Wilmore and Suni Williams. Additional tests must be conducted before disconnection, team officials emphasized; Starliner experienced helium leaks and thruster problems, causing the Crew Flight Test (CFT) mission to be extended from the originally planned ten days after launch on June 5. NASA and Boeing have not yet announced a return date for Starliner, but say it won't happen until after July 2. spacewalk.
As a test flight, the unexpected at CFT was in a sense expected. But a major milestone is coming soon: Starliner is expected to begin its first operational mission to the ISS in early 2025. Known as Starliner-1, it is manifested to carry at least three astronauts to the ISS for a normal six-month mission. .
NASA's Steve Stich recently told reporters (before the most recent delay on Friday) that the certification timeline for Starliner-1 may be shifting to the right, but the focus now is on bringing CFT to a safe conclusion.
"We're not going to fly another mission like this with the helium leaks," Stich, manager of NASA's Commercial Crew Program, said during a June 18 conference call. That discussion will come 'later this summer, [to] put all the work in front of us after the vehicle returns with the crew, and then figure out the path forward.
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Starliner's first helium leak was found on the launch pad in early May, following a scrub-down due to a valve problem with the capsule's United Launch Alliance Atlas V rocket. The leak was not considered an immediate threat to the launch, but NASA and Boeing discovered a design vulnerability whereby, if enough of Starliner's reaction control system (RCS) thrusters went offline, the capsule's reentry could be affected. The team certified an additional reentry mode in simulations with the astronauts before Starliner was cleared for launch again.
CFT made it off the pad without incident on June 5, but Starliner experienced problems with five of its 28 RCS thrusters en route to the ISS for docking. The first docking attempt was rejected, but Starliner succeeded in the second docking attempt a few hours later. Four new helium leaks also occurred after Starliner reached space; Fault tree analysis and other work to determine the root cause is ongoing.
Starliner also had problems with its RCS thrusters during the first unmanned ISS docking in May 2022, but these appear to be due to a different issue, officials said at the June 18 briefing. The why is still in the early stages.
Both NASA and Boeing have repeatedly emphasized that timelines are not the priority with CFT, and that something unpredictable can always happen. The mission's two astronauts, former U.S. Navy test pilots, said much the same thing.
The mission team is using the extra time in space to understand how Starliner's service module behaves, as it contains most of the spacecraft's fuel and power and will be discarded during landing. The RCS thrusters now appear to be largely working, while helium leaks are "stable and less than measured." [before]" said Mark Nappi, vice president and program manager of Boeing's commercial crew program.
Notably, CFT achieved 77 of the original 87 flight test objectives; the last 10 will be evaluated during undocking and landing, he added.
Related: NASA is weighing the potential impact of helium leaks and more on Boeing's Starliner astronaut test flight
The work after CFT will include trying to understand what "causes the thrusters to have low thrust and then be turned off" by flight control systems, as the astronauts encountered this month, Stich said. The "silver lining" of the expanded mission is that it will allow teams to collect data in space that could not be collected on the ground, potentially saving time in troubleshooting issues later.
"My goal is to get the quirks out of the system before we get to the stage where we will use this vehicle to rotate crew members and then bring them back at the end of six months," Stich said. Some ideas are already coming to mind: for example, perhaps mission teams will change the "aggressiveness of the rendezvous profile" so as not to stress the thrusters, firing them a little less.
"We fully intend to eliminate these, call it nuisances, in flight," he added. "The good thing about the current situation is that we can stay a little longer, as we have spoken, and collect as much data as possible so that we can fully understand this, or as best as we can. , so we can eliminate it. And our intention is to eliminate these problems completely."
However, NASA and Boeing do not anticipate that additional test flights will need to be conducted to resolve the issues prior to Starliner certification.
"We characterize these issues as learning issues and as additional refinement that we need to do to the vehicle to be able to do that [achieve] a certification for our vehicle," Nappi said. "I don't view this as some sort of flight safety issue that we would have to fly an unmanned vehicle to further demonstrate the system."
Starliner-1 will carry NASA astronauts Mike Fincke and Scott Tingle, along with Canadian Space Agency astronaut Josh Kutryk. The crew is well into training and works closely with CFT. Fincke is a long-term astronaut with Starliner and was backup for CFT, for example, while Kutryk served as capcom (capsule communicator) during the crucial ascent phase of the test mission.
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Starliner and SpaceX's Dragon capsule are tasked with ferrying NASA-led astronaut crews to and from the ISS. Both Boeing and SpaceX received multibillion-dollar contracts in 2014 for taxi services that were originally expected to begin in 2017. However, technical and financing issues have pushed back that timeline for both suppliers.
SpaceX, which borrows its design from its robotic Dragon cargo spacecraft, which has been operational since 2012, achieved its first human flight in 2020. Starliner is a new spacecraft and encountered more development problems, which often arise with complex new space projects.
The path to CFT was postponed after the first unmanned test failed to reach the ISS in December 2019 due to technical problems. The second unmanned mission took place in 2022, but in 2023 more Starliner problems were discovered with parachute loading and flammable tape on much of the capsule's wiring.
