> The testing leads the teams to believe that the thrusters are prone to overheating during docking. Higher temperatures may have caused propellant to vaporize, interrupting the mixing of oxidizer and fuel required for the thrusters to properly work, which then reduced the thruster pressure and resulted in the lower readings.
But surely they have tested the trusters in a vacuum chamber for the durations they planed to burn them (plus a safety margin).
Would be cool to know if such testing didn't happen. Or if it happened but missed the issue for some reason. Perhaps the problem only happens in the integrated configuration, not when they were testing trusters individually? Or perhaps something with sun illumination?
Watching a launch in person made me really fear for the astronauts lives even though they were on a reliable vehicle. I can’t imagine the concern of this crew and their family knowing they need to try and come home on this platform.
I hope NASA will wait for a supply mission to bring a Crew Dragon and test Starliner further.
> I hope NASA will wait for a supply mission to bring a Crew Dragon and test Starliner further.
IMO, both Boeing and NASA are under quite a lot of pressure to not require further tests from Boeing because there are just enough Atlas Vs (the rocket that Starliner launches on) for Boeing to complete it's contractual obligations.
Any further tests would deplete that stock.
While I do think a certain amount of grace is due to a vehicle like Starliner - all space vehicles are relatively bespoke and have a consistent level of minor problems - its track record is not great. All 3 demonstration flights have had serious issues with the service module. And because Boeing can't examine the actual hardware once the capsule lands, they have a limited ability to determine the true root cause.
Case in point - NASA and Boeing throught they understood the helium leak before launching... and after 4 more leaks popped up realized that they actually didn't.
>IMO, both Boeing and NASA are under quite a lot of pressure to not require further tests from Boeing because there are just enough Atlas Vs (the rocket that Starliner launches on) for Boeing to complete it's contractual obligations.
>Any further tests would deplete that stock.
I hear what you are saying and it likely affects their decision, but lack of hardware in the future should not be a consideration in this decision at all. If there is any concern, safety of the crew should be priority one.
IIRC, Aerojet is the sub on this system. Surely they understand propulsion well and it is unfortunate that Boeing's name is taking the hit.
> Aerojet is the sub on this system. Surely they understand propulsion well and it is unfortunate that Boeing's name is taking the hit.
From what I can tell, Aerojet is hot garbage.
They tried to build a new engine for NASA during Constellation and their incompetence is one of the (many) reasons the program got cancelled.
They tried to build a new engine to compete with Blue Origin over the Vulcan 1st stage contract and lost. To a company which had never built an engine with a preburner before.
I know they've got a lot of heritage, but the only worthwhile engine they currently make (RL-10) is a variant of a decades old design. I'm entirely unsurprised that the service module they're responsible for isn't working well.
I think we all agree that their lives are more valuable than whatever the cost of the recovery mission would be to bring them home safely, but isn't it disheartening that the only reason we could agree to spend that much money to save so few lives is because of the spectacle of it all?
But surely they have tested the trusters in a vacuum chamber for the durations they planed to burn them (plus a safety margin).
Would be cool to know if such testing didn't happen. Or if it happened but missed the issue for some reason. Perhaps the problem only happens in the integrated configuration, not when they were testing trusters individually? Or perhaps something with sun illumination?