2024-08-25 09:34:00
The series of difficulties encountered with the Starliner have led to the heavy decision not to use this spacecraft to bring Butch Wilmore and Suni Williams back to Earth. A blow to Boeing, which is already mired in repeated setbacks with its airliners.
“NASA has decided that Butch and Suni will return with the Crew-9 crew next February, and that the Starliner will return without a crew”, said NASA chief Bill Nelson at a press conference following a decision-making committee on Saturday.
Relief for the two astronauts stuck on the ISS: a “radical” solution has been found for their return to Earth
He justified this decision as a safety precaution but expressed confidence in the duo of SpaceX and Boeing to transport astronauts into space, stating he is “100% sure” that Boeing will once again launch the Starliner with a crew.
For weeks, Boeing and NASA teams have been conducting tests to better understand the cause of the issues encountered during flight, particularly concerning the spacecraft’s thrusters. The problem has been identified, but it is too difficult to predict how the spacecraft will behave during the return journey, NASA explained. The main concern is whether the Starliner will be able to generate the necessary thrust to break away from orbit and begin its descent to Earth. Attempting a return with these malfunctions “was simply too risky for the crew”, said Steve Stich, a senior NASA official. Thus, the Starliner will leave the ISS for a return to Earth without its crew “in early September.”
A regular SpaceX mission, named Crew-9, is scheduled to launch at the end of September carrying only two astronauts instead of four. It is to remain docked at the ISS until its planned return to Earth in February. It would then also bring back the two stranded astronauts from Boeing alongside the two Crew-9 astronauts. “SpaceX is ready to help NASA in any way possible”, reacted SpaceX’s number two, Gwynne Shotwell, on X. Butch Wilmore and Suni Williams, who are stuck in orbit for several more months, “fully support the agency’s decision and are ready to continue their mission aboard the ISS”, said Norm Knight, a NASA official, during the press conference.
NASA commissioned Boeing and SpaceX ten years ago to develop a new spacecraft each to transport its astronauts to the ISS. With two vehicles, it wishes to avoid being left without a solution in case of problems with either one. However, Elon Musk’s company has significantly outperformed Boeing and has been the sole American space taxi for four years now.
Analysis of this unprecedented situation with Professor Gregor Rauw, astrophysicist and space exploration specialist (University of Liège).
Was bringing the astronauts back with SpaceX the right decision? Why?
From NASA’s perspective, it was the only possible and logical solution. After many tests on the Starliner (both in space and on the ground), there remained too significant a margin of uncertainty regarding the operation of the thrusters to ensure a safe return for the two astronauts. NASA lost two space shuttles (each time with 7 astronauts) because safety was not the priority then; they cannot afford to lose another crew. Especially in a context where a backup solution exists!
What impact for Boeing? Is this the end of the Starliner program, in your opinion?
In public opinion, Boeing is losing face even more. But I think they still have a chance to recover because NASA continues to assert (rightly) that they want at least two capsules capable of reaching low Earth orbit and the ISS. Nevertheless, this will cost Boeing as NASA has a fixed-price contract (4.2 billion dollars). Therefore, the overruns will be entirely on Boeing’s account. There are clearly things to review regarding the management of Boeing’s space division, but I believe they can recover from this.
As for SpaceX, Elon Musk must be thrilled, but on the other hand, it is important to remember that Bill Nelson, NASA’s chief, has clearly reiterated NASA’s desire to have another vehicle besides the Crew Dragon. Given Musk’s whimsical and unpredictable nature, I think this is easily understandable.
In retrospect, what was the major mistake or bad decision that led to this situation, in your opinion?
It’s hard to say. First, let’s remember that this is indeed a test flight. By definition, it is a mission where problems are identified. If there was a mistake, it likely occurred upstream of the current mission, in the sense that the issues with the thrusters encountered during the two uncrewed tests were not resolved before launching the current mission.
What is the identified problem with the Starliner spacecraft?
According to explanations provided by NASA, the thrusters reach temperatures that are too high, which causes a part to expand and then block the flow of one of the propellants to the thruster, preventing it from functioning. One surprising thing mentioned yesterday is that the operating temperatures of the thrusters are outside the margins set by the manufacturer. This is clearly something that needs to be reviewed and improved in the future.
Since Starliner is dysfunctional, is detaching it from the ISS (where it is currently docked) for the empty return journey not dangerous for the International Space Station? Could it, for example, collide with it during departure…?
NASA and Boeing engineers must develop a simplified separation sequence allowing the Starliner to move away from the ISS more quickly to reduce risks. While there is no such thing as zero risk, it is less risky than asking a crew to go through the very critical atmospheric re-entry sequence with a propulsion system that could fail under intensive use (as required for the deorbiting maneuver and atmospheric re-entry).
What about the psychological state of the astronauts, who have to stay for 8 months instead of 8 days? What about their supplies, since their stay was not planned?
The astronauts are trained for this eventuality. I believe the psychological burden is primarily on their families. The ISS resupply is not in danger. In addition to Crew Dragons, there are Russian uncrewed Progress spacecraft that supply the ISS (there was a delivery last week). The impact will thus be on the stay of Butch Wilmore and Sunita Williams, as well as on the two Crew-9 astronauts who will have to remain on the ground… All the other astronauts will carry out their missions as originally planned.
Can this episode be considered unique? Has there ever been a case where the return of a test flight did not happen, or a similar incident occurred in the past?
Yes and no… Except for the first Crew Dragon flight, previous test flights (Mercury, Gemini, Apollo, Space Shuttle) had no choice: there was no space station to which the spacecraft could dock. So, no possible backup solution, the return had to happen with the spacecraft regardless of its condition. Problems/incidents during the early flights of a spacecraft have occurred several times: the first flight of the Soyuz capsule ended with the death of cosmonaut Vladimir Komarov due to a parachute issue. Less dramatically, during Apollo 7 (the first crewed flight of the Apollo program), there was a very long series of problems reported by the astronauts. The current situation is therefore unprecedented, primarily because NASA has the luxury of having a Plan B to bring astronauts back to Earth…