Boeing's Starliner (CST-100) - Discussion Thread 4

[Athelstane]

An oxygen mask won't save you if depressurization occurs. Just send up an unmanned craft to replace their disabled craft. It's simple.

Well, no, certainly not complete depressurization, at any rate. Probably better to hypothesize something like what happened on ASTP's reentry.

Obviously a replacement Soyuz would much more desirable than to take everyone back on a Commercial Crew vehicle if that is an option, but the necessity in mind here is something more catastrophic - that a severe MMOD event depressurizes not only key ISS modules but the docked Soyuz, too; or in the alternative, cuts off cosmonauts' access to the Soyuz, perhaps. Such that ISS no longer constutitues a safe harbor and that all ISS crew must return to Earth immediately.

Obviously, as I said, it is a very unlikely scenario. Just not completely impossible.

[LouScheffer]

Of course it is theoretically possible. And if something truly ISS-ending armageddon scenario happened it would obviously be better to try it than dying.

MY POINT (and people keep missing it), is that this is not an official escape plan that NASA has demanded that the commercial partners support.
- There is no requirement that a Cargo Dragon needs to support 7 crew on the floor and be able to return them safely. (an oft cited scenario on this forum since Cargo Dragon first flew)
- For the same reason there is also no requirement for being able to pack in 7 people into a Starliner (or Crew Dragon) that only has 4 seats, 4 custom-fitted IVA suits, and consumables for 4.
Because the moment such requirements appear, the mountain of paperwork and costs would be immense, and the cost of the vehicles would go up. (and be delayed)

Think of it as packing in 10 people in a car that seats 5. Technically possible? Yeah. Safe or advisable? No way. Do you see any car manufacturer stating that 'in a pinch you can fit 10 people in this car'. Never.

I believe this view is contradicted by NASA history.  Consider Apollo 13, from Apollo 13, We Have a Solution.  In a previous Apollo 10 simulation, the crew was lost because using the LM as a lifeboat involved some tricky problems.  So folks started working on procedures:

“Many people had discussed the use of the LM as lifeboat, but we found out in this sim,” that exactly how to do it couldn’t be worked out in real time, Legler says. At the time, the simulation was rejected as unrealistic, and it was soon forgotten by most. NASA “didn’t consider that an authentic failure case,” because it involved the simultaneous failure of so many systems, explains Hannigan.  But [...] he tasked his deputy, Donald Puddy, to form a team to come up with a set of lifeboat procedures that would work, even with a crippled command module in the mix.

No design changes were involved:

Legler “figured out how to reverse the power flow, so it could go from the LM back to CSM,” through the umbilicals, says Hannigan. “That had never been done. Nothing had been designed to do that.” Reversing the power flow was a trick that would ultimately be critical to the final stages of Apollo 13’s return to Earth.

Although the initial work was informal, it was intended to become parts of NASA official plans, even before Apollo 13:

Puddy’s team worked on the procedures, looking at many different failure scenarios and coming up with solutions. Although the results hadn’t yet been formally certified and incorporated into NASA’s official procedures, the lunar module controllers quickly pulled them off the shelf after the Apollo 13 explosion.

So there is  certainly precedent for official NASA procedures, designed to work with equipment not designed for the procedures in mind.

[Comga]

For once I am on LouScheffer’s side of the argument.
However, the discussion is no longer specifically about CST-100 Starliner, this thread’s purpose.
If people want to speculate on where three extra passengers would fit in Starliner, or how Starliner bulkhead features would help or hurt them, or what cabin fixtures could be repurposed as couches, then it might be about CST-100.
Failing that, it has wandered off-topic.
It might make for a good thread on its own.