Crew mysteriously dies

[Cavalier]

Hm. I'm flying the 107 along, following the checklist like a good astronaut, but when I get to the LM familiarization at 56 hours, I open the PAMFD to transfer my guys, and lo! They are all dead! :facepalm: I never got any messages, didn't evacuate the atmosphere, or anything strange along the way, so. I go back through various checkpoints, and find they died somewhere between about 7 GET and 22 GET. That's primarily just coasting, so I'm not sure where anything catastrophic could happen. Any thoughts?

 

[Thymo]

What are your readings in regards to Cabin pressure, temperature, CO2 and the like?
The crew only dies if one of those is off limits.

 

[Cavalier]

Weirdly, I went back and checked those, and they are all in limit. All things being equal, I suppose, and assume, I have something set incorrectly in the ECS. To quote Tom Hanks, "it has to be the oxygen." In reality, I think that if O2 wasn't flowing the crew would die, but the LiHO would be overwhelmed and CO2 would rise, but I don't know how this is implemented. It doesn't seem possible to change cartridges, so I guess the CO2 is a bit of a work-around, but maybe if O2 wasn't flowing correctly, that might cause death. I'll re-fly the mission and pay closer attention to the way the automatic checklist sets everything. The problem is that, although I've read the G&N manuals for several iterations of the CM, I can't seem to find a manual for the bloody plumbing! I'll update this thread if I figure out the stupid thing I must have done. One thing I wish, though--if a situation occurred where the crew was in danger, MCC's flight surgeon would be burning up the wires, but I never got a message. I don't know the inner workings of MCC, but it would be quite nice if it, or the sim in general, would just casually mention that, "uh, 11? You seem to be about to croak..." :lol:

 

[Cavalier]

Just for luck, I'll include the first scenario I have saved where the crew turned dead.

 

[Urwumpe]

The problem is that, although I've read the G&N manuals for several iterations of the CM, I can't seem to find a manual for the bloody plumbing!

Could be that Guidance & Navigation is not talking about the plumbing. :lol:


The subsystem you are looking for is the Environmental Control System.


This here specifies the regular checks:

And here, you can find the details about the plumbing:

https://history.nasa.gov/afj/aoh/aoh-v1-2-07-ecs.pdf

 

[macieksoft]

I have checked the attached scenario.

Seems like you had stowaway Japaneese kamikaze in your CM who turned off suit demand regulators ;-)

Crew was suited and suit circuit was closed (so the crew was sealed from cabin atmosphere). Without functioning regulators and with suit circuit isolated from cabin crew eventually died from lack of oxygen.

It is clearly visible that suit circuit pressure have dropped a lot.

To fix that issue make sure that at least one suit demand regulator is selected or the suit circuit is open (connected to cabin trough suit circuit return valve).

 

[Cavalier]

Thanks very much! The "plumbing" doc is just the sort of thing I was looking around for. G&N is well covered, being the more interesting information, but anyone who's house has sprung a leak will find the plumbing of immediate interest.

Now to the kamikazi in the cabin... I think that fairly early on I probably set them wrong. Of course, the crew should be well out of their suits at this point. Is there a way to do that BTW? I'm carefully going through the ECS checklist again, and at this point I'm vaguely remembering having some difficulty here. For instance, at the point, "O2 FLOW ind - 0.2-0.45 lb/hr," it is pegged low. At this point, I seem to remember fiddling with a few things, assuming that I missed or just incorrectly set something important, and probably turned the suit flow returns off to see what effect they had, and just forgot to turn them on again. I fear that SIMSUP would have me grounded after that.

 

[macieksoft]

I think that there is no yet a simulation of a crew in cabin for the CM, it is working in LM anyway.

You can however simulate crew partially suited or so by simply opening the suit circuit return valve.

Generally there are some rules on how to set things up.
For crew sealed in suits you need at least one suit demand regulator working. Procedures also call to disable emergency repress (high flow) regulator.

For crew in cabin (or partially suited) i think there is no need for it (not sure about particular procedures). However procedures require to enable the emergency repress regulator, just in case of puncture (puncture won't happen in sim anyway).

 

[meik84]

For crew in cabin (or partially suited) i think there is no need for it (not sure about particular procedures).

Jupp, the cabin press regs should take care of that. However, the suit demand regs remain on, just in case the crew has to return to the suited condition. When it remains in the right way, you can't forget to set it up in the right way.
Anyway, in reality the astronauts would've noticed a closed suit demand reg very quickly: as they breath away the oxygen, the suit pressure drops below cabin pressure quite quickly, so that the suits collapse ("clingy suit"). The difference between a correctly pressurized suit and a clingy suit is hard to ignore, so they would be on the pink pages of the systems checklist very quickly.

 

[Cavalier]

So, just to update, I've flown the new mission all the way back to where I discovered the dead crew with no issues. The only difference in settings are the suit returns. I followed the checklist with a closer eye this time, and noticed that the comment beside turning suit power off seems to imply that sets the cabin state, and just to be on the safe side, I returned suit flow to full for each, which is at the end of each DOFF. Pressure is where it is supposed to be and everyone lives, so I conclude that the phenomenally stupid thing I did was, probably during doffing the suits, to turn the return valves off.

 

[meik84]

the comment beside turning suit power off seems to imply that sets the cabin state

Not to my knowledge. SUIT PWR is a mere telecommunications (and telemetry) thing, it powers the astronauts biomed harness and headset. To get out of the suit you had to disconnect the com umbilical from the suit's outer connector and your biomed harness from the suit's inner cabling. To do that while there's still power on the umbilical is not a good thing, so its turned off while doffing the suit and back on again when you had all your cables and electrodes back to where they should be.
When I remember right, the only thing that makes the difference in the sim between "suited" and "unsuited" is the suit circuit return valve. AFAIK the suit flow control valves (300,301,302) don't do anything at all at the moment.

 

[Cavalier]

It's very hard to know if the crew suited/unsuited state is even taken into account. On the LM, at least you can see their state. It makes me wonder if you could do then entire mission suited (which sort of makes my skin crawl). The cabin flow or full flow probably wouldn't matter as much IRL, as it just seems to control how fast cabin air is recycled through the LiOH, odor filters, and dehumidifying filters. If I read the plumbing doc correctly you would have them on full flow. Certainly turning them off IRL would be bad--in the CMP checklist, it notes that turning them all off while the compressor was running would blow the head gasket after about 1 minute. Oops.

 

[Thymo]

Right now suited/unsuited state is not taken into account in the CM yet. The only way to simulate this right now is to open the suit circuit return valve.
We do have an overhaul planned for the CM ECS so eventually you'll be able to control suit state there too.

 

[Cavalier]

That will make things less confusing.

 

[Cavalier]

Now I'm at the point where we power up and check out the LM. Gak!!! :blink: The LM plumbing is more confusing than the CM's. Anyone happen to have or know where to find a doc on the LM ECS?

 

[Urwumpe]

Now I'm at the point where we power up and check out the LM. Gak!!! :blink: The LM plumbing is more confusing than the CM's. Anyone happen to have or know where to find a doc on the LM ECS?

Did you already look at the LM Activation Checklist as a starter?

Generally, take a look here:

https://www.hq.nasa.gov/alsj/alsj-LMdocs.html

EDIT: The LM Familiarization Manual seems to contain the coarse descriptions and drawings that you might be looking for.

 

[Cavalier]

Fantastic! Thanks for the link. As for the checklist, I'm following the one in-sim, and I have a checklist for Apollo 12. The problem is, I don't really understand what each specific action actually does, so if I need to figure out something that's happening outside of a checklist, I don't know what might be set wrong, or what needs to be changed. For instance, while doing the regulator check, when I dumped the pressure, by the checklist, the cabin light and master alarm failed to light, as it should have in the checklist. If I had any idea what each control did in relation to the space craft and to each other, I could troubleshoot that, but I just had to press on, and hope nothing was seriously broken or improperly set. I like to at least feel like I know what's going on, ya know!

 

[indy91]

The AOH Volume I for the LM has a section on the ECS, maybe that helps.

EDIT: This document is also quite useful: https://www.hq.nasa.gov/alsj/LM06_Environmental_Control_ppEC1-25.pdf

 

[Cavalier]

Great! Again, many thanks. I'm going back through the LM power up a few times, to get a good feel for it. So far, the full Apollo 11 mission (t-4 hour start) has run quite well. MCC has provided virtually everything (no LOS/AOS, but that's a minor thing), and the check list is good as gold. I was a little confused during the AGS, with entries of a single digit. Will the AGS fill in the remaining zeros? Anyway, I found an AGS manual, so that's all good. Is the Apollo 11 mission finished through splash down? -edit- Two additional LM questions: At one point, the checklist seems to indicated actions on a panel 9. I think I've tried every conceivable combination of navigation around the inside, and can't find those controls. Are they superfluous at this point? Also, it has the crew manipulating the window shades. Is this implemented and I just haven't figured out how to do it, or is that superfluous?

Fantastic work, all around! I'll post after success (or failure) with any comments generally.

 

[indy91]

MCC has provided virtually everything (no LOS/AOS, but that's a minor thing), and the check list is good as gold.

Yeah, the flight plan doesn't really specify if AOS/LOS times should be given to the crew for every orbit, but in reality they got those times in almost all cases. For Apollo 8 and 10 the MCC does give the AOS/LOS times, so maybe I'll implement it for 11 as well. I'll have a look at it.

I was a little confused during the AGS, with entries of a single digit. Will the AGS fill in the remaining zeros? Anyway, I found an AGS manual, so that's all good.

You have to always fill in every digit. So the checklist item e.g. "410+1" becomes: Clear 410 + 10000 Enter". You know that the input went in if the displays are all becoming blank.

Is the Apollo 11 mission finished through splash down?

MCC updates are done through splashdown, yes. I think rcflyinghokie, who worked on the checklists for the Checklist MFD, has gotten through his latest pass of checklist additions and fixes only up to about the time of lunar landing. The rest of the mission is covered by the Checklist MFD, but expect a few more inaccuracies.