N_Molson
Addon Developer
Hi, :hello:
It seems I have a little problem to solve, in a realistic way, and I'm not sure of the way to proceed.
I have two vessels docked together, with the hatch sealed. Vessel A has an atmosphere of 100% oxygen, at 300 mmHg (those are the conditions into an Orlan spacesuit). Vessel B has an Earth-like atmosphere of 160 mmHg O2 and 600 mmHg N2 (total : 760 mmHg). Vessel B atmosphere must not change.
I want to open the hatch and transfer cosmonauts (and I need to do that in the two ways). Of course I have to equalize the pressure (else the differential will generate a nasty blow). But I also have to modify the atmosphere composition of Vessel A so that it matches Vessel B.
Let's see the B->A transfer case. The procedure would be to :
1) decrease the 100% O2 atmosphere pressure to 160 mmHg
2) open a pressurized bottle of N2 until the total pressure reaches 760 mmHg
3) open the hatch and transfer the crew.
4) close the hatch
5) restore the atmosphere composition to 300 mmHg 100% O2.
And here is the problem. How to do step 5 ? Is there a way to get rid of N2 without losing the precious O2 (with current technology) ? If not, there's my proposal, what do you think of it ?
5a) Before or after the transfer, the crew completes a standard EVA pre-breathing procedure (which is not too long with Russian suits, more pressurized than US ones).
5b) The crew enter their Orlan suits, and connect them to the Vessel B ECLSS.
5c) The suits are sealed and the atmosphere composition inside is slowly set to 100% O2 300 mmHg (N2 is gradually purged as the pressure drops and the circuit is only supplied with pure O2).
5d) Once the necessary period of adaptation is elapsed, and the crew report they are fine, the hatch between A & B is sealed.
5e) Vacuum is made in Vessel A (it is designed for this anyway). All gases are purged.
5f) Vessel A is filled with pure O2 until the pressure reaches 300 mmHg.
5g) At this moment, the atmosphere composition & pressure are the same inside and outside the suits (except that there are traces of H2O and CO2 inside the suit). The cosmonauts are free to exit the suits, or at least, open the visor and remove the gloves.
So, your two cents ? :tiphat:
It seems I have a little problem to solve, in a realistic way, and I'm not sure of the way to proceed.
I have two vessels docked together, with the hatch sealed. Vessel A has an atmosphere of 100% oxygen, at 300 mmHg (those are the conditions into an Orlan spacesuit). Vessel B has an Earth-like atmosphere of 160 mmHg O2 and 600 mmHg N2 (total : 760 mmHg). Vessel B atmosphere must not change.
I want to open the hatch and transfer cosmonauts (and I need to do that in the two ways). Of course I have to equalize the pressure (else the differential will generate a nasty blow). But I also have to modify the atmosphere composition of Vessel A so that it matches Vessel B.
Let's see the B->A transfer case. The procedure would be to :
1) decrease the 100% O2 atmosphere pressure to 160 mmHg
2) open a pressurized bottle of N2 until the total pressure reaches 760 mmHg
3) open the hatch and transfer the crew.
4) close the hatch
5) restore the atmosphere composition to 300 mmHg 100% O2.
And here is the problem. How to do step 5 ? Is there a way to get rid of N2 without losing the precious O2 (with current technology) ? If not, there's my proposal, what do you think of it ?
5a) Before or after the transfer, the crew completes a standard EVA pre-breathing procedure (which is not too long with Russian suits, more pressurized than US ones).
5b) The crew enter their Orlan suits, and connect them to the Vessel B ECLSS.
5c) The suits are sealed and the atmosphere composition inside is slowly set to 100% O2 300 mmHg (N2 is gradually purged as the pressure drops and the circuit is only supplied with pure O2).
5d) Once the necessary period of adaptation is elapsed, and the crew report they are fine, the hatch between A & B is sealed.
5e) Vacuum is made in Vessel A (it is designed for this anyway). All gases are purged.
5f) Vessel A is filled with pure O2 until the pressure reaches 300 mmHg.
5g) At this moment, the atmosphere composition & pressure are the same inside and outside the suits (except that there are traces of H2O and CO2 inside the suit). The cosmonauts are free to exit the suits, or at least, open the visor and remove the gloves.
So, your two cents ? :tiphat:
