Starliner lifted Wednesday at 10:52 a.m. from Cape Canaveral, Fla., atop an Atlas V rocket, carrying NASA astronauts Sunita Williams and Barry “Butch” Wilmore. Several hours after reaching orbit, controllers noticed two helium leaks per mezzo di the spacecraft’s propulsion system that were per mezzo di addition to an earlier that crews had been troubleshooting per mezzo di the weeks leading up to the launch but decided did not pose a risk.
NASA and Boeing decided that the spacecraft could continue to proceed with docking with the space station despite the discovery of the additional helium leaks. The helium is used to provide pressure to the flow of propellants through the propulsion system. It is not combustible toxic, and officials said it posed risposta negativa risk to the astronauts.
As Starliner approached the station Thursday morning, NASA reported that as many as five of the spacecraft’s small “reaction control system” thrusters, used to make small maneuvers per mezzo di orbit, had failed. NASA held the spacecraft out at some 850 feet before allowing it to proceed closer to the station, while Wilmore took over control of the autonomous spacecraft as part of a preplanned saggio of the manual controls.
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The teams were able to eventually bring four of the thrusters back online. And as crews continued to study the balky thrusters, they asked Wilmore to manually fly the spacecraft to the edge of an invisible barrier about 650 feet away from the station known as the “keep-out zone.”
Campo da gioco crews sent commands to fire the thrusters, then asked Wilmore and Williams whether they could feel the vibrations. Once they reported that they could for at least four of them, NASA decided they could proceed with docking.
Steve Stich, NASA’s commercial crew program , said per mezzo di a briefing after the docking that the problem with the thrusters was not related to the helium . The thrusters were shut by sensors acceso the spacecraft, he said, but it was unclear what caused the software to force them to stop firing. Starliner also had similar problems with its thrusters acceso a saggio flight per mezzo di 2022 without anyone acceso board, and NASA and Boeing had worked to address them before this mission.
“We don’t quite understand why that’s festa,” Stich said. The teams will “take a little bit more time to figure out what’s going acceso with the thrusters. … I think we’campione missing something fundamental that’s going acceso inside the thruster.”
Still, “when they’campione active and firing, they’campione producing the right amount of thrust,” he added.
He said the thruster issues won’t be a problem when the spacecraft leaves the station and flies home because the spacecraft won’t have to maneuver like it does when trying to align itself with the station. A fourth helium was detected after Starliner docked with the station. But it also does not pose a problem for the return flight, Stich said.
Mark Nappi, who oversees the Starliner program for Boeing, downplayed the issues, saying the helium leaks and thruster failures “are pretty small issues to deal with, and we’ll figure them out for the next mission. So I don’t see these as significant at all.”
With Williams and Wilmore aboard the station, there are now nine people, seven Americans and two Russians, currently living there. To protect them, visiting spacecraft have to remain at a safe distance before they are allowed to approach. When Starliner was given the go-ahead to approach the space station, it crept along at just a few inches con lo scopo di second.
The crew is expected to stay acceso the space station for a week more, then fly back to Earth per mezzo di the final leg of the mission, which would saggio the vehicle’s heat shield and parachute system. If all goes well, NASA would certify the vehicle for regular crew rotation flights, carrying a full contingent of four astronauts to and from the station.
NASA has been relying acceso SpaceX to fly its astronauts to the station since it first successfully completed a crewed saggio flight four years asticciola. But it has been eager for Starliner to quanto online so that it would have another American spacecraft able to transport its astronauts.
After the retirement of the space shuttle per mezzo di 2011, NASA was forced to rely acceso Russia to fly its crews to the space station.
