Posts: 438
From: NSW, Australia
Registered: May 2005

posted 08-29-2009 08:25 PM               

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I saw a question about the Apollo 1 suits that got me wondering: the David Clark A1C suits worn by the Apollo 1 crew were designed to maintain an internal (suit) atmosphere of roughly 100% O2 at about 3.5 PSIA.

In the case of the AS204 fire, when they had faceplates down / suit sealed and the spacecraft cabin pressure was at about 16.7 PSIA of about 100% O2, what was the pressure inside the suit? Did it maintain it a cabin pressure? If so, what about oxygen toxicity?

I've looked at the Apollo Operations Handbook section of the report (Appendix C-1, AOH section 2.7) but can't figure it out from the diagramme.

Posts: 342
From: Houston, Texas, USA
Registered: Jun 2004

posted 08-29-2009 09:19 PM            

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Per the Apollo 1 fire report, there was oxygen flow through all three suits, but apparently only at cabin pressure. (I imagine they might have slightly inflated the suits just for comfort).

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John Charles
Houston, Texas

Posts: 438
From: NSW, Australia
Registered: May 2005

posted 08-30-2009 06:16 AM               

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It doesn't quite make things clear. With the cabin pressurised to some 16.7 PSI with 100% O2, if the suit circuit was similar then they ran the risk of oxygen toxicity.

How was this avoided?