Could Dragon V1 be a lifeboat if need be?

[LABHOUSE]

It should fit a suited astronaut it is about a 2 metre diameter.

[DaveofDefeat]

There are emergency oxygen candles, that would buy them some time on the capsule.

[Tommygun]

There are emergency oxygen candles, that would buy them some time on the capsule.

You would still need to remove the CO2.

I know they don't have enough EVA suits for all the crew, but do they have the other "orange" type flight pressure suits or something similar to rescue balls for everyone else?

Also isn't dragon 1 designed to return science experiments? They wouldn't want high G's damaging those.

Edited November 22, 2014 by Tommygun

[Guest]

Dragon 1 reentry G-loading should be survivable, and I think that they've got chemical CO2 scrubbers as well as O2 candles. After all, they'd need to remove CO2 in any emergency, Dragon or not.

As for EVA suits, they have two in the US airlock, plus Orlans in the Russian segment. Dunno how many, but they're in there. The hatch is wide enough, but all that would be a moot point, though, since I don't think they could repressurize the Dragon after EVAing into it. It has no airlock of any kind, and only one pressurized compartment.

Edited November 22, 2014 by Guest

[Guest]

They can take oxygen bottles with them and repressurize D1, but all in all, preparations would take a lot of time, too long for any real emergency. They basically need to convert D1 to D2 except Draco engines.

[Kryten]

You would still need to remove the CO2.

I know they don't have enough EVA suits for all the crew, but do they have the other "orange" type flight pressure suits or something similar to rescue balls for everyone else?

The orange suits were for shuttle, the Soyuz launch suits don't have independent life support.

[EzinX]

The orange suits were for shuttle, the Soyuz launch suits don't have independent life support.

How does that work, exactly? They lost a Soyuz crew when a valve opened too soon, so the suits are to protect against unplanned depressurization of the capsule. But if the capsule is depressurized, how will the Soyuz life support continue to work? Is it somehow sealed off from the cabin air? (the fans/C02 scrubber cartridges)

So, ok, in this scenario everyone is in space suits squatting against the bottom of the dragon capsule. It doesn't have any flight controls, so the coder monkeys at spacex have bodged together some code in a hurry to order it to make the burns for a rapid reentry. The question is, can you get a survivable reentry profile with just one pass? (where the first time your capsule scrapes the upper atmosphere, you have enough drag to lose enough velocity that your trajectory doesn't end up in space again)

If so, that means that the maximum time you need to wait for reentry is about 90 minutes (time for 1 orbit) and in most cases it's going to be a lot less than that. Of course there's all kinds of issues with this, including mundane things like cooling - where's the waste heat going to go?

Edited November 22, 2014 by EzinX

[Kryten]

The system shuts off the vents to the cabin in response to pressure loss, there are separate direct connections to the suits.

[EzinX]

The system shuts off the vents to the cabin in response to pressure loss, there are separate direct connections to the suits.

So if the air leak is inside the life support system itself (say a micrometeorite punctured the capsule right there) you're still toast.

Doesn't NASA have some kind of short duration life support pack on the back of each seat for the space shuttle to solve this problem? You don't need much, just a small bottle of compressed oxygen and a C02 scrubber and a fan, similar to the rebreathers that miners have.

[magnemoe]

So if the air leak is inside the life support system itself (say a micrometeorite punctured the capsule right there) you're still toast.

Doesn't NASA have some kind of short duration life support pack on the back of each seat for the space shuttle to solve this problem? You don't need much, just a small bottle of compressed oxygen and a C02 scrubber and a fan, similar to the rebreathers that miners have.

System has two functions, one is pressure loss in cabin, second is life support fail both can happens at once as you say.

In cause of fail suits are run on the oxygen supply, if you have pressure fail you want to run on 0.2 bar pure oxygen anyway.

If not you would feed oxygen mixed with old air and went the cabin if pressure or co2 level get to high.

Next you do an emergency abort an landing, as in find a suitable continent to land on. You do not need more than an 2 hour supply worst case.

And you don't need to move around so its no need to disconnect, worst case you have to operate some manual overrides, however they are mostly to avoid mission abort not to do an emergency landing.

Benefit of an pod over an shuttle is that you can land everywhere with some exceptions like mountains.

The shuttle had an bail out system who might have worked, it needed it as it had to land on a runway.

[Kryten]

So if the air leak is inside the life support system itself (say a micrometeorite punctured the capsule right there) you're still toast.

Doesn't NASA have some kind of short duration life support pack on the back of each seat for the space shuttle to solve this problem? You don't need much, just a small bottle of compressed oxygen and a C02 scrubber and a fan, similar to the rebreathers that miners have.

It's the best solution they could get with the space and mass requirements as they are, especially as the risk of such a leak is very low. Shuttle's portable units were needed because astronauts on shuttle could have been required to bail out.

[sgt_flyer]

Well, regarding ISS safety procedures - one of the likely sources of damage would be orbital debris on collision course.

in case the ISS is on a collision trajectory with such debris,

they first try to use the station's RCS thrusters to move it out of harm's way long before it could happen.

If ISS can't be placed far away enough from the debris trajectories, ISS crews have to shelter themselves inside the soyuz spacecrafts, lock their hatches, and wait there (still docked to iss) until the danger has passed.

The reason behind this is that the soyuz themselves have a much smaller profile than iss - between their size and iss's they have much less chances to be hit by those debris (and the could evacuate immediately if the need arise)

Of course, if the spacecraft happen to be hit and destroyed, the crew aboard it will be lost - but that would have been the case too if they stayed on ISS only to see their lifeboat getting destroyed.

(And yes, iss crews already had to take shelter on the soyuz several time while some debris passed less than 10km from the station)

So in the end, to have a scenario where the station and a soyuz are damaged before the crew could react, would require to come from an incident occuring onboard the station or at close proximity from it, with immediate threat resulting from it.

Ex : automated docking problem causing a cargo to hit the station, or something like that - such incidents could only happen because of several failures at once (after all, even automatic cargos are monitored ny the crew and ground control - which are ready to push the abort button if they have the slightest hint that it could threaten the station. (Which means the redundant cargo systems failed)

If such event would happen, this kind of damage would be most likely to kill at least part of the crew.

Edited November 23, 2014 by sgt_flyer

[Guest]

I can think of one scenario where an unexpected collision could happen. A spent rocket stage that would pass close to the station would be promptly avoided, but if it exploded (would take one heck of a bad luck, but would be possible with some of them), this could pepper the station with high velocity debris regardless, and likely without much of a warning. This is what did one of the Salyuts in (they didn't manage to send the crew, thankfully), and, to add insult to injury, it was the very stage that put it into orbit. While we're now much better at passivation/deorbiting those, but debris from spent stages are still a problem.