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Boeing Starliner returns home to an uncertain future

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Boeing Starliner returns home to an uncertain future

So far, NASA has paid Boeing about $2.7 billion of the $4.6 billion total potential value of its commercial crew contract, according to Finch. The Starliner contract that NASA awarded Boeing in 2014 was originally worth a maximum of $4.2 billion, but contract modifications since 2014 have added $400 million to the deal. Most of the money NASA has paid Boeing to date has been for Starliner development costs, while the remaining funds in the contract cover future service payments for operational flights.

So if Boeing pulls out of Starliner, the company would be giving up nearly $1.9 billion in potential revenue for NASA, even more than the $1.6 billion in losses it has so far incurred with the program.

Ready for departure

Since the decision last month to bring Starliner home without its crew, NASA officials have reviewed plans for the spacecraft to depart the space station on autopilot. Preparations included updating Starliner’s software parameters to allow for autonomous undocking. Then, last Thursday, NASA officials convened a Flight Readiness Review and cleared Starliner to return to Earth.

“All respondents have given a thumbs-up on that review, pending the operational status of the vehicle and weather conditions for landing,” said Steve Stich, NASA’s commercial crew program manager. “Therefore, we will proceed to undock and land on Friday.”

As Starliner approached the space station on June 6, five of the craft’s 28 Reaction Control System (RCS) thrusters stopped working, forcing Wilmore to take manual control while ground controllers attempted to regain control of some of the control jets.

Engineers tested the thrusters and analyzed data for more than two months to track down the cause of the failure. Ground crews managed to get four of the five failed thrusters working again, but NASA officials could not ensure that the same thrusters — or perhaps more — would not overheat again and fail when Starliner leaves the station and heads for reentry.

Investigators found that repeated pulses of RCS jets caused temperatures in the thrusters to rise. This likely caused a seal on each of the problematic thrusters to bulge and deform, restricting fuel flow, according to NASA officials.

Stich said Wednesday that potential solutions to the problem on future Starliner flights range from changing the way the craft ignites its thrusters to prevent overheating, to changing the seal design, to modifying the doghouse-shaped propulsion pods that house the thrusters in the spacecraft’s service module. The design of these “doghouses” causes them to retain heat like a thermos, exacerbating the thermal problem.

Boeing and NASA must also resolve helium leaks that plagued Starliner’s test flight. Engineers believe a separate set of degraded seals is causing leaks of helium, which the spacecraft uses to pressurize the propulsion system and power thrusters. Ground controllers have closed valves to isolate the helium system and plug the leaks while Starliner has been docked to the space station. 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 from undocking to landing Friday night.

Wilmore and Williams originally planned to stay at the space station for about eight days, but will now remain residents at the complex until February, when they will return home on a SpaceX Dragon spacecraft.

Dana Weigel, NASA’s ISS program manager, said Wednesday that the Starliner astronauts, both veterans of previous six-month stays on the space station, are fully trained to perform spacewalks, operate the lab’s robotic arm and conduct science and maintenance experiments. They will be fully integrated into the space station’s long-duration crew, which normally includes seven residents. With the extended stay of the Starliner crew, the station’s crew size has grown to nine people.

The crew reorganization forced NASA to Two astronauts removed from SpaceX’s next manned Dragon flight The launch to the ISS will occur later this month, leaving two empty seats to accommodate Wilmore and Williams when the Dragon spacecraft returns to Earth early next year. This upcoming SpaceX crew rotation will bring the station’s crew size back to its usual complement of seven American astronauts and Russian cosmonauts.

This story originally appeared in Ars Technica.

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