The first astronaut mission aboard the Boeing Starliner is grounded indefinitely.
Starliner will not launch as planned on Saturday (May 25), which was the latest launch date after several delays in recent weeks. NASA officials communicated the delay late Tuesday (May 21) and did not yet provide a specific cause. But the team has been investigating a small helium leak in a Starliner thruster in recent weeks.
“The team has been in meetings for two consecutive days to review the flight rationale, system performance and redundancy. Progress continues in these areas and the next possible launch opportunity continues to be discussed,” the email update said. part.
Starliner’s Crew Flight Test (CFT) mission to the International Space Station is, as NASA and Boeing officials have repeatedly emphasized, a developmental project. In previous briefings, officials said they always emphasize safety over schedules. NASA CFT astronauts Butch Wilmore and Suni Williams, both former US Navy test pilots, have said much the same thing.
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Starliner appeared ready to fly on May 6, but the countdown was halted just two hours before takeoff while Wilmore and Williams were strapped into the spacecraft. (The helium leak was also ongoing during this time, but at that time the engineers did not consider that a problem for the launch.)
The postponement was ultimately invoked after United Launch Alliance (ULA) discovered a problem with the oxygen relief valve on the Atlas V rocket that the duo was set to launch from the Cape Canaveral Space Force Station on the coast near Orlando, Florida. The Atlas V has been flying missions since 2002 with 100% launch success, but CFT will be the rocket’s first crewed launch.
ULA decided it would be safer to address the “buzzing” valve – which opened and closed quickly – without astronauts on board. After a few hours of evaluation, the team decided to pull the stacked rocket back to a shelter to replace the valve.
While at the ULA facility, the team investigated the helium leak and announced delays, first until May 21 and then until May 25. flange on a single reaction control system thrust,” NASA officials wrote in an earlier update.
Helium is a non-flammable gas and poses no risk during ground operations, but the proper pressure is needed to deliver propellant to Starliner’s dozens of engines. According to multiple media reports, this helium leak was found in a part of the spacecraft used for small maneuvers in orbit.
Starliner is only allowed to dock in one port of the ISS’s Harmony module during this test mission, meaning NASA must keep that spot open for CFT’s launch. If the fix takes several weeks, it could be difficult for NASA to keep the site open as the ISS hosts other cargo and astronaut missions. That’s likely a factor behind the uncertainty surrounding the launch date.
Williams and Wilmore had remained in quarantine due to the launch delays and flew back to NASA’s Johnson Space Center in Houston in mid-May. NASA has not said whether the astronauts will emerge from their quarters, but if the delay continues for many weeks, it is likely they will leave to focus on other CFT training tasks.
Development delays are common with new space programs. Boeing and SpaceX were both commissioned by NASA in 2014 to send astronauts to the ISS using commercial crew vehicles. The target date for astronaut flights at the time was 2017.
SpaceX, borrowing from its cargo Dragon design started in 2012, successfully flew its first Crew Dragon with astronauts in 2020. Starliner has waited much longer.
Starliner failed to reach the ISS during its first unmanned test flight in 2019 due to a software glitch that sent the spacecraft into the wrong orbit. A connecting flight reached there safely in 2022 after the dozens of issues were resolved, among other delays partly due to the outbreak of the coronavirus pandemic in March 2020.
CFT was further delayed in 2023 after the team discovered that the capsule’s parachutes could carry less load than expected, and discovered that flammable tape covered much of the wiring inside the spacecraft. However, these problems are behind the team, NASA and Boeing officials said in the spring.