Atlas V: Boeing Starliner Orbital Flight Test-2 (OFT-2 today)

[MultimediaMan]

Starliner has got a long way to go. The "Doghouse" (Service Module) has really got them in the Doghouse.

But I think the toughest issue is with the cooling loops in the capsule; those are the bits that NASA is going to nitpick. The STS (Space Shuttle) had numerous problems over the years with it's cabin and payload cooling loops. Likewise, the ISS has had it's fair share as well (all Ammonia based-coolants). NASA is not looking forward to dealing with a new generation of them.

The problems of the ammonia-based are well-understood; it is a very light, flammable, liquid, and readily absorbs water (which is a problem). It is a reactive compound and there are several metals which it should never be exposed to... Ammonia, is a weak conductor of electricity (Pure water is not a conductor), but can be very strongly conductive with only the smallest contamination of Chloride (Hydronium ions). This makes it really important to have a clean system free of materials which can contaminate it.

Most of the problems historically relate to contaminated coolant (Common prompt cooling failure #1) or incorrect charging/purging of the system (Common failure #2). In a humid place like Florida this is a real issue. The normal workaround is to heat the coolant and separate out the water; Even on a running system, a water extraction system must be present to ensure the function and continued operation of the cooling system. In Zero-G, water collection/ separation/ disposal is really hard to do and depending on how they designed it, may or may not be easy to remedy.

[Dr Mordrid]

I think all of what you mentioned is going to delay the Starliner crew flight test (CFT) at least a year, perhaps longer. It really is a clusterfrack.

If CFT slips to 2024+ NASA should just cut Starliner loose and toss some money at Sierra Space for the Dream Chaser spaceplane. The cargo version, DC-100, should be flying within a year. The crew version, DC-200, is targeting 2026. The national security version, DC-300, comes later.

[MultimediaMan]

I think all of what you mentioned is going to delay the Starliner crew flight test (CFT) at least a year, perhaps longer. It really is a clusterfrack.

If CFT slips to 2024+ NASA should just cut Starliner loose and toss some money at Sierra Space for the Dream Chaser spaceplane. The cargo version, DC-100, should be flying within a year. The crew version, DC-200, is targeting 2026. The national security version, DC-300, comes later.

Yeah, Starliner is not what we need for today's manned missions. I costs way too much and is a dead end as far as usefulness to the ISS and whatever comes after.

[Dr Mordrid]

Yeah, Starliner is not what we need for today's manned missions. I costs way too much and is a dead end as far as usefulness to the ISS and whatever comes after.

I wouldn't be surprised if SpaceX offered an LEO version of Dragon XL, the large cargo vehicle they plan to use for the Gateway lunar station. At least until Starship is in routine service.

On the other hand, Starship is larger in volume than ISS or these new space stations. It could almost serve as an as needed station.