To date, NASA has paid Boeing roughly $2.7 billion of the total potential value of the commercial crew contracts: $4.6 billion, Finch said. The Starliner contract NASA awarded Boeing in 2014 was originally worth up to $4.2 billion, but contract modifications since 2014 have added $400 million to the contract. Most of what NASA has paid Boeing to date has been for Starliner development costs, with the remaining funds under the contract to cover service payments for future operational flights.
So if Boeing were to walk away from Starliner, the company would give up nearly $1.9 billion in potential revenue from NASA — more than the $1.6 billion it’s lost on the program so far.
Ready to go
Since deciding last month to return Starliner without a crew, NASA managers have been studying plans for the spacecraft to leave the space station on autopilot. Preparations included updating Starliner’s software parameters to allow for an autonomous detachment. And last Thursday, NASA officials held a flight readiness review that gave them the go-ahead for Starliner’s return to Earth.
“Pending spacecraft operations and weather conditions at landing, that review unanimously voted ‘go,'” said Steve Stich, NASA’s commercial crew program manager. “So we’re working toward undocking and landing on Friday.”
As Starliner approached the space station on June 6, five of the spacecraft’s 28 Reaction Control System (RCS) thrusters went offline, requiring Wilmore to take manual control while ground controllers attempted to restore some of the control jets.
Engineers spent more than two months testing the thrusters and analyzing data to determine what caused them to fail. Ground teams were able to bring four of the five failed thrusters back online, but NASA officials were unsure whether those same thrusters, or more, would overheat and fail again as Starliner leaves the station and heads for re-entry into the atmosphere.
Investigators found that repeated firing of the RCS jet caused a rise in temperature inside the thruster, which NASA officials said likely caused a seal inside the problem thruster to bulge and deform, restricting the flow of propellant.
Stich said Wednesday that there are a variety of possible solutions to the problem on future Starliner flights, including changing the way the spacecraft’s thrusters fire to prevent overheating, altering seal designs and modifying the dog-house-shaped propulsion pods to which the thrusters are attached on the spacecraft’s service module. These “dog-house” designs retain heat like a thermos, exacerbating the thermal problem.
Boeing and NASA must also resolve a helium leak that plagued Starliner’s test flights. Engineers believe the leak, which contains helium the spacecraft uses to pressurize its propulsion system and pump propellant to its thrusters, is caused by a different seal that has deteriorated. While Starliner was docked to the space station, ground controllers closed valves to isolate the helium system and stop the leak. Those isolation valves will be opened before Starliner leaves the space station, but NASA officials say the spacecraft has more than enough helium for the six-hour flight between undocking and landing Friday night.
Wilmore and Williams were originally scheduled to stay at the space station for about eight days, but will now remain residents of the facility until February, when they return home aboard SpaceX’s Dragon spacecraft.
Dana Weigel, NASA’s ISS program manager, said Wednesday that both Starliner astronauts have spent six months aboard the space station and are fully trained to perform spacewalks, operate the laboratory’s robotic arm and perform maintenance and science experiments. They will be fully integrated into the space station’s long-term expedition crew, which typically consists of seven occupants. The Starliner crew’s extended stay increases the station’s crew size to nine.
Due to crew changes, NASA Two astronauts removed from next SpaceX Dragon flight The Dragon spacecraft will launch to the ISS later this month, freeing up two seats for Wilmore and Williams when it returns to Earth early next year. The SpaceX crew swap will return the ISS’s crew to its usual lineup of seven US astronauts and one Russian cosmonaut.
This story originally Ars Technical.
