I am pretty sure this has been discussed before but I am having a hard time finding the prior discussions on it. Here is the question: in an emergency, could a cargo Dragon 1 or 2 or a cargo DC be used as a rescue spacecraft (for the descent from ISS to Earth) without any modifications to it?I imagine that it could be done if the astronauts used a spacesuit of some kind.
Would you have to use an EVA suit?
You could use oxygen candles but that would increase the pressure inside. Unless you could reduce pressure to a minimum before detaching.There was a big discussion more than a year ago regarding this topic and if I recall correctly, the main issue was that Dragon v1 cannot undock/un-berth without internal command from ISS, so somebody would have to stay behind.
Quote from: yg1968 on 05/20/2018 04:22 pmWould you have to use an EVA suit?The internal volume of the dragon 1 is 10m^3.For six astronauts, that is 1.6m^3 each or so.You can breath that amount of air for four hours and on average only have breathed it once.At the end of this time, it is going to become quite unpleasant.First 'nasty' effects perhaps an hour afterwards.On some nominal dragon flights, six crew would have probably survived, if they could open the door at landing.However, if you can pick the appropriate time so you are landing in range (more or less) of emergency recovery forces, there is no good reason to take more than an hour - landing happens around 40 min after the entry burn.
Quote from: IRobot on 05/20/2018 07:29 pmYou could use oxygen candles but that would increase the pressure inside. Unless you could reduce pressure to a minimum before detaching.There was a big discussion more than a year ago regarding this topic and if I recall correctly, the main issue was that Dragon v1 cannot undock/un-berth without internal command from ISS, so somebody would have to stay behind.Couldn't they just vent the excess air?