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 NASA awarded Boeing in 2014 originally had a maximum value of $4.2 billion, but contract amendments since 2014 have added $400 million to the deal. Most of the money NASA has paid Boeing to date is for Starliner development costs, while the remaining funds under the contract cover future service payments for operational flights.
So, if Boeing walked away from Starliner, the company would be giving up nearly $1.9 billion in potential revenue from NASA, on top of the $1.6 billion in losses it has incurred on the program so far.
Ready to Go
Since the decision last month to fly the Starliner home without its crew, NASA managers have reviewed plans for the spacecraft to leave the space station in autopilot mode. Preparations include updating the Starliner’s software parameters to enable autonomous undocking. Then, last Thursday, NASA officials convened a Flight Readiness Review and cleared the Starliner to return to Earth.
“Everyone polled ‘go’ on that review, pending the operational status of the vehicle and the landing weather,” said Steve Stich, NASA’s commercial crew program manager. “So we’re moving towards undocking and landing on Friday.”
As Starliner approached the space station on June 6, five of the ship’s 28 Reaction Control System (RCS) thrusters went offline, requiring Wilmore to take manual control as ground controllers attempted to retract some of the control jet.
Engineers tested the thrusters and analyzed data for more than two months to track down the cause of the thrusters’ failure. Ground teams were able to bring four of the five failed thrusters back online, but NASA officials could not assure themselves that the same thrusters, or perhaps more, would not overheat and fail again while the Starliner has left the station and is heading for re-entry.
The investigators found that the repeated pulses of the RCS jet led to an increase in temperature in the thrusters. This likely caused a seal in each of the problem thrusters to bulge and deform, restricting propellant flow, according to NASA officials.
Stich said Wednesday that possible solutions to the problem in future Starliner flights range from changing the way the ship fires its thrusters to prevent overheating, to changing the design of the seal, to changing the shape doghouse propulsion pod where the thrusters are in the service module of the spacecraft. The design of these “doghouses” causes them to retain heat like a thermos, exacerbating the thermal problem.
Boeing and NASA must also resolve the helium leaks that plagued the Starliner test flight. Engineers believe a separate set of damaged seals is causing leaks of helium, which the spacecraft uses to pressurize the propulsion system and propel the propellants in its thrusters. Ground controllers have closed valves to isolate the helium system and seal off leaks while the Starliner is docked with the space station. Those isolation valves will open before the Starliner leaves the space station, but NASA officials said 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 on the space station for about eight days, but will now remain as residents of the complex until February, when they will return home aboard 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 robotic arm of the lab, and perform maintenance and scientific experiments. They will be fully integrated into the space station’s long-term crew, which typically includes seven residents. With the extended stay of the Starliner crew, the station’s crew size grew to nine people.
The crew shakeup forced NASA to remove two astronauts from the next SpaceX Dragon crew flight to launch to the ISS later this month, leaving two seats empty to accommodate Wilmore and Williams when the Dragon spacecraft returns to the Earth early next year. SpaceX’s upcoming crew rotation will return the station’s crew size to its usual complement of seven US astronauts and Russian cosmonauts.
This story originally appeared on Ars Technica.
