The first Boeing Starliner to fly astronauts into space performed a crucial test in space on Saturday (27 July) as the next mission faces months of delays.
Tested by engineers Starlinerthe Reaction Control System (RCS) thrusters to prepare for a broader agency review that will assess the spacecraft’s readiness for landing NASA astronauts Butch Wilmore and Sunny Williams sometime in August, if all goes according to plan.
“Teams will evaluate the results of the test firings over the next few days as they work on comprehensive surveys before reviewing the agency’s readiness,” NASA officials said in a statement on X, formerly Twitter, on Saturday.
Starliner encountered problems during the astronauts’ debut docking with International Space Station (ISS) on June 6. Although it eventually succeeded, helium leaks and problems with five thrusters delayed the event. The Starliner is designed to leave the ISS in the event of an emergency, but before the astronauts attempt a nominal exit, engineers are trying to figure out why these problems occurred.
Determining what happened is key to the readiness of the next mission, Starliner-1, which is scheduled to spend six months on the ISS in 2025. On Friday (July 28), NASA announced a delay of that mission until August 2025. early winter.
Connected: 50 days after ISS launch, Boeing Starliner astronauts still have no landing date
NASA and Boeing have not yet identified how they will solve Starliner’s problems, whether through design or by changing the way astronauts navigate future fire engines, officials told reporters on Thursday (July 27). But in the meantime, Starliner-1 will be delayed to give “a little more time for Starliner to complete the modifications from the new tests,” NASA’s Steve Stich told reporters. Stitch is a program manager for NASA’s Commercial Crew.
The current Starliner space mission, known as the Crew Flight Test (CFT), was originally expected to last 10 days. It’s now almost 55 days in space, with the astronauts living off a supply supply on the ISS that’s already there for the unexpected. The mission is in development, and as such there were uncertainties with the schedule, NASA and Boeing emphasized before the mission.
In a blog post, Boeing officials said the new RCS test was performed to “confirm the operation of each thruster” in short bursts, up to 1.2 seconds long each. (The RCS has 28 thrusters, but engineers removed one thruster from testing weeks ago because they determined it could not fire properly for the return to Earth.) Each thruster tested showed peak thrust ranging from 97 percent to 102 percent.
“The helium system also remained stable,” Boeing officials wrote. Wilmore and Williams did not directly fire the thrusters, but remained aboard the Starliner and reported what they saw on the ground. (Both are former US Navy test pilots and have years of experience in aerospace development programs.)
Thruster ground tests this month revealed why the CFT’s RCS has problems: If it fires repeatedly, especially in conjunction with the Orbital Maneuvering and Control System (OMAC) thrusters, the “doghouses,” or isolated bays housing groups of thrusters RCS, tend to heat up, leading to thrusters with Teflon insulation from their seals. NASA and Boeing also said that this problem could not have been detected on the ground before the CFT was flown.
Starliner is one of two systems funded by NASA to send astronauts to the ISS. The other is the Crew Dragon built by SpaceX. Crew Dragon first performed a crewed test in 2020 using a design based on SpaceX’s Cargo Dragon ISS vehicle. Since the test, Crew Dragon has flown 11 missions to the ISS: 8 semi-annual missions on behalf of NASA and 3 weekly missions on behalf of Axiom Space.
Crew-9, SpaceX’s ninth operational mission to the ISS, is scheduled to lift off no earlier than Aug. 18, and the Starliner should be home by then, NASA said.
