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Apollo Discussions => The Reality of Apollo => Topic started by: BILLR on January 12, 2013, 07:24:24 PM

Title: Apollo pressure suits.
Post by: BILLR on January 12, 2013, 07:24:24 PM
After moon EVA, how did the crew re-introduce the commander and LMP pressure suits back into the command module without contaminating the internal atmosphere with possible particles of moon surface material floating around?
Title: Re: Apollo pressure suits.
Post by: BILLR on January 12, 2013, 07:35:33 PM
Sorry, ignore that question. They re-entered with without pressure suits. Stupid of me.
Title: Re: Apollo pressure suits.
Post by: Mag40 on January 12, 2013, 07:37:56 PM
Sorry, ignore that question. They re-entered with without pressure suits. Stupid of me.

IIRC, the Apollo 12 crew came back in their birthday suits.
Title: Re: Apollo pressure suits.
Post by: LunarOrbit on January 12, 2013, 07:38:16 PM
They did bring the pressure suits back to Earth inside the CM. I'm not sure how they were cleaned, but it was probably a futile effort.
Title: Re: Apollo pressure suits.
Post by: Glom on January 12, 2013, 07:48:54 PM
Weren't they all contaminated hence the MQF?
Title: Re: Apollo pressure suits.
Post by: ka9q on January 12, 2013, 08:10:49 PM
Lunar dust contamination was a serious problem. Many astronauts said it's the single most significant technical problem that will have to be addressed by any future lunar exploration program.

Apollo worked out a few procedures to lessen the problem, such as opening a small vent in the LM after docking with the CSM to cause an airflow into the LM that would tend to sweep dust back into the LM. But a lot of dust still ended up in the CM.
Title: Re: Apollo pressure suits.
Post by: Allan F on April 05, 2013, 10:37:14 AM
They did bring the pressure suits back to Earth inside the CM. I'm not sure how they were cleaned, but it was probably a futile effort.

As I understand it, the pressure suits were covered with a specialized garment to protect against abrasion and micrometeroites when it was used on the moon, and the cover was discarded before liftoff, along with outer boots and helmet. All that was retained was the liquid cooled garment and the pressure suit itself.
Title: Re: Apollo pressure suits.
Post by: ka9q on April 05, 2013, 04:49:36 PM
You sure about that? Aside from gloves, boots, the LEVA and the straps and covers associated with the PLSS, I don't think anything was removed from the suits after the lunar EVAs. The outer layer of the pressure suit is beta cloth, a teflon-coated fiberglass fabric chosen after the Apollo 1 fire for its non-flammability in an oxygen atmosphere. It still seems widely used today.

A special plastic bubble was used to protect the Lexan pressure helmet from scratches before earth liftoff, but it was removed after they were seated in the command module.

Title: Re: Apollo pressure suits.
Post by: Allan F on April 05, 2013, 05:23:43 PM
The suit used inside the spacecrafts weighted around 29 kilos, the add-on suit for EVA weighted an additional 35 kilos. Plus the PLSS and OMS. So yes, I'm pretty sure.

The astronauts wore suits at launch, and they were significally less bulky than the suits worn while on the surface.
Title: Re: Apollo pressure suits.
Post by: ka9q on April 05, 2013, 05:30:20 PM
Are you accounting for the difference between the EVA suits worn by the CDR and LMP, and the intra-vehicular suit worn by the CMP prior to Apollo 15?

Also, are you looking at the A7L used prior to Apollo 15, or the A7LB used from 15 onward?
Title: Re: Apollo pressure suits.
Post by: Allan F on April 05, 2013, 05:35:27 PM
Figures are from A7LB. And yes, I'm aware they had different suits, relating to their assignments.
Title: Re: Apollo pressure suits.
Post by: ka9q on April 05, 2013, 05:36:19 PM
If I'm looking at the same figures as you, I think the EVA add-on mass consisted of the LEVA, PLSS, OPS, etc. I simply don't see anything else that could account for such a difference in mass -- except maybe the liquid cooling garment.


Title: Re: Apollo pressure suits.
Post by: Allan F on April 05, 2013, 06:22:01 PM
Reading that again, I see I was mistaken. I had the impression that the 'indoor' suit was complemented by an added exterior tougher shell, when they went outside. Still, some parts of the EVA-suit was discarded before ascent, to save weight.

Edit: So to minimize contamination, the best they could do was to discard the boots, since they were the most contaminated. Wonder why they didn't wear a set of legwraps, which could be discarded like the rip-off visors open-cockpit racecardrivers wear do.
Title: Re: Apollo pressure suits.
Post by: ka9q on April 05, 2013, 08:15:53 PM
The boots were discarded mainly to save weight since they were no longer needed. Same with the PLSS. The OPS and LEVA were kept in case of an emergency EVA transfer from the LM to the CSM, and they were also used during the CMP's EVA on Apollos 15-17.

By the time the seriousness of the dust problem was realized, it was probably too late for any major design innovations to deal with it. And it was serious; just about every Apollo lunar astronaut who was asked for their advice on returning to the moon said it was their single biggest unsolved problem.
Title: Re: Apollo pressure suits.
Post by: Allan F on April 05, 2013, 08:48:55 PM
Like tiny glass shards going everywhere. I really wouldn't like to breathe that. Once in zero-G, didn't the enviromental systems start to take it out of the air?
Title: Re: Apollo pressure suits.
Post by: VQ on April 06, 2013, 08:04:36 PM
Like tiny glass shards going everywhere. I really wouldn't like to breathe that. Once in zero-G, didn't the enviromental systems start to take it out of the air?
I would be curious to hear the answer to this. I would imagine electrostatic forces played a major role as well, making the dust "stick" to some surfaces until disturbed.
Title: Re: Apollo pressure suits.
Post by: Allan F on April 07, 2013, 12:36:01 AM
Regarding the boots, I wonder how much feel for the surface they provided?
Title: Re: Apollo pressure suits.
Post by: ka9q on April 08, 2013, 02:00:23 AM
As far as I know, none of the Apollo lunar astronauts has developed lung cancer as you might expect if lunar dust behaved like asbestos. The grains are sharp, uneroded by rain or wind, so they tend to stick to everything. But they probably don't continually fracture and work their way deep into the lungs as asbestos does.
Title: Re: Re: Apollo pressure suits.
Post by: Glom on April 08, 2013, 02:22:11 AM
As far as I know, none of the Apollo lunar astronauts has developed lung cancer as you might expect if lunar dust behaved like asbestos. The grains are sharp, uneroded by rain or wind, so they tend to stick to everything. But they probably don't continually fracture and work their way deep into the lungs as asbestos does.

But even if it did, is it necessarily carcinogenic?
Title: Re: Apollo pressure suits.
Post by: ka9q on April 08, 2013, 02:46:38 AM
My understanding (and I'm not a biologist or doctor or anything like that) is that certain types of asbestos cause lung cancer by repeatedly cleaving into smaller and smaller fibers that work their way deep into the alveoli of the lungs where they cannot be flushed out by the usual protective mechanisms.
Title: Re: Apollo pressure suits.
Post by: Al Johnston on April 08, 2013, 06:19:49 AM
I think that's asbestosis, not actually a form of cancer...
Title: Re: Apollo pressure suits.
Post by: ka9q on April 08, 2013, 09:15:10 AM
Ah, I see it's a distinct condition that increases the risk of various malignancies like lung cancer and mesothelioma. Fortunately I've never known anyone with it.

Title: Re: Apollo pressure suits.
Post by: Noldi400 on April 08, 2013, 04:43:48 PM
My understanding (and I'm not a biologist or doctor or anything like that) is that certain types of asbestos cause lung cancer by repeatedly cleaving into smaller and smaller fibers that work their way deep into the alveoli of the lungs where they cannot be flushed out by the usual protective mechanisms.

Regolith dust shouldn't be carcinogenic in the way that asbestos is.  Individual asbestos fibers are so freakin' tiny ( .06 um - an average human cell is around 80 um in diameter) that they can actually penetrate cells and get into contact with chromosomes, which interferes with normal cellular division and is thought to set off the unregulated cell growth of cancer.

AFAIK, regolith doesn't share this characteristic - although there are many carcinogenic mechanisms and it could, I guess, have one of the other ones.
Title: Re: Apollo pressure suits.
Post by: Abaddon on April 10, 2013, 02:33:08 PM
My understanding (and I'm not a biologist or doctor or anything like that) is that certain types of asbestos cause lung cancer by repeatedly cleaving into smaller and smaller fibers that work their way deep into the alveoli of the lungs where they cannot be flushed out by the usual protective mechanisms.

Regolith dust shouldn't be carcinogenic in the way that asbestos is.  Individual asbestos fibers are so freakin' tiny ( .06 um - an average human cell is around 80 um in diameter) that they can actually penetrate cells and get into contact with chromosomes, which interferes with normal cellular division and is thought to set off the unregulated cell growth of cancer.

AFAIK, regolith doesn't share this characteristic - although there are many carcinogenic mechanisms and it could, I guess, have one of the other ones.
Disclaimer: I am in no way a medical person.

As I understand it, regolith is carcinogenic in the same way as volcanic ash on earth. If I recall correctly, silicosis(sp?) is the offending beasty and regolith would have the same effects on the lungs.
Title: Re: Apollo pressure suits.
Post by: BazBear on April 10, 2013, 07:54:59 PM
Silicosis is indeed a nasty disease, but not a type of cancer.