NASA officials and Boeing said Tuesday that they successfully removed two valves from the Starliner spacecraft and sent them to the Marshall Space Flight Center in Alabama for further analysis.
The forensic exam – the two valves are examined using a variety of techniques, including a CT scan – is part of Boeing’s ongoing effort to diagnose the problem with the “stuck” valves, which led to the unmanned abortion on Aug. 3 Starliner’s test flight resulted in a five hour countdown to launch, during a routine procedure that 13 of the 24 valves that control the flow of nitrous tetroxide oxidizer through the spacecraft’s service module would not alternate between closed and open.
An initial diagnostic attempt on the launch pad was unsuccessful, so the Atlas V rocket and spacecraft were rolled back to an integration facility. After further inspection and testing there, the engineers decided to “unstack” the spacecraft and return it to the Boeing spacecraft processing building at the Kennedy Space Center. This eventually led to the vehicle being further dismantled and several valves removed.
Boeing’s chief aerospace and launch engineer Michelle Parker said during a news conference with reporters Tuesday that the company had a pretty solid hypothesis as to what went wrong. At some point during the 46 day period that the vehicle was refueled – and when the valves were found to be stuck – moisture must have gotten into the spacecraft. This moisture combines with the oxidizer and creates nitric acid, which starts the corrosion process.
Parker said dew points at the launch site were high in August, and although the vehicle was designed to operate in Florida’s humidity, there is physical evidence that humidity is still the culprit. Boeing and NASA engineers now want to try to recreate the corrosive response under similar test conditions so that they can be confident of the cause and the countermeasures they have taken.
The company and NASA will advance the work in Florida, Alabama, and the Boeing test site in White Sands, New Mexico. All of this will take time, admitted Boeing’s commercial crew program manager John Vollmer. He said Boeing is now aiming for the “first half” of 2022 for the Starliner unmanned test flight. (A source told Ars that the date is “no earlier than” May 2022).
This mission is officially called Orbital Flight Test-2 or OFT-2. The company flies OFT-2 at its own expense, $ 410 million, after an unmanned Starliner mission in December 2019 that went wrong due to software issues. The company’s technicians and engineers worked long and hard to fix the software after the OFT-1 flight, only to have these new hardware issues pop up at take-off controls on the pad in early August.
NASA hopes Boeing can get Starliner to fly so it can have a second launch system alongside SpaceX’s Crew Dragon vehicle to get its astronauts to and from the International Space Station. Assuming Boeing safely locks the OFT-2, Vollmer said the company and NASA would like to have about six months to review the data and prepare for a manned test flight. That would mean the earliest possible launch date for Starliner’s first mission with astronauts in late 2022. What is more realistic is that the mission may not fly until early 2023.
After this flight, NASA will confirm that Starliner is ready for regular, operational astronaut flights.
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As part of its commercial occupation program, NASA has ordered six post-certification missions from SpaceX and Boeing. SpaceX successfully completed its manned demonstration mission in 2020 and is scheduled to launch its third certified crew-3 mission to the International Space Station on October 31. A fourth and fifth mission are to follow in 2022.
During Tuesday’s press conference, Steve Stich, NASA’s commercial crew program manager, said the agency was negotiating additional flights for SpaceX – and possibly Boeing. He said details of these contract extensions could be revealed within the next few months. Given the issues discussed on Tuesday, it now seems possible that SpaceX could sign its first six-mission contract before Boeing flies its first certified mission. However, Stich is confident that Boeing will get there.
“I have no reason to believe that Boeing will not be able to get Starliner up and running,” said Stich. “We will solve this problem, and then we will have two space transport systems as we want.”
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