Are these real photos of Apollo 1 burned suits?

[apollo16uvc]

I don't believe it. NASA doesn't make photos like that public.

But if anyone can find a NASA source for the images, that would help.

http://telescopewatch.in/blog/2017/01/27/apollo1/

[Obviousman]

Yes. They were released as part of a report, some time ago.

[Halcyon Dayz, FCD]

I don't believe it. NASA doesn't make photos like that public.

Why do you presume NASA has a choice?

[Allan F]

Relevant pages have been left out of the 3 reports about the Apollo 1, Challenger and Columbia accidents. Namely those who discussed the remains of the astronauts. To my knowledge (which is limited, I know) those have never been made available publicly.

[Rob48]

I find it incredible that the decision was ever made to use a pure oxygen environment inside the capsule. Surely anybody who has done high-school chemistry knows that just about anything will burn under such conditions, and there were lots of very smart people involved in designing Apollo. So how did such a seemingly crazy course of action come about?

[QuietElite]

I find it incredible that the decision was ever made to use a pure oxygen environment inside the capsule. Surely anybody who has done high-school chemistry knows that just about anything will burn under such conditions, and there were lots of very smart people involved in designing Apollo. So how did such a seemingly crazy course of action come about?

Well the problem with that was only before launch since during the flight the cabin pressure was lower than atmospheric pressure here on earth so a fire under these conditions would have been comparable with a fire on earth.

Amy Shira Teitel also made a Youtube video about that topic on her Vintage Space channel.

[bknight]

I find it incredible that the decision was ever made to use a pure oxygen environment inside the capsule. Surely anybody who has done high-school chemistry knows that just about anything will burn under such conditions, and there were lots of very smart people involved in designing Apollo. So how did such a seemingly crazy course of action come about?

Rightly or wrongly all pervious manned mission ground tested capsule in pure oxygen same as operating conditions.  No fires in any previous test, so perhaps the engineers were a little complacent.  The Apollo test conditions were changed to nitrogen/oxygen combination and  purge valve was opened to vent that mixture into less pressure environment, replaced by pure oxygen during flight.

[Northern Lurker]

My understanding is that pure oxygen atmosphere was selected because:
-while in space, the only pressure inside the capsule was partial pressure of oxygen. This enabled lighter pressure vessel (=capsule) construction
-without nitrogen in capsule atmosphere, there was no need for heavy and cumbersome tankage, piping and regulator
-no risk of decompression sickness in EVA or leak event
-in microgravity there is no convection to carry combustion products away and bring fresh oxygen to fire, reducing fire hazard in orbit

The need for high pressure oxygen during ground testing rose from requirement of positive pressure inside the capsule to avoid contaminants entering. Because ECS produced only oxygen, they used it. Also there hadn't been any problems reported before. Soviets lost one cosmonaut on earth in low pressure, pure oxygen habitat but it was kept secret.

AFAIK the Apollo capsule should have been free of flammble materials but one by one flammable materials were installed inside for convenience's sake.

All those factors combined with go fever caused that nobody thought it was dangerous. Until one electrical fault arced... Sadly, the normalization of deviance seem to be part of human nature, especially under pressure. Eroding of O-rings or hits from insulation foam weren't  considered dangerous either, until the Challenger and Columbia disasters...

Lurky

[ka9q]

Well the problem with that was only before launch since during the flight the cabin pressure was lower than atmospheric pressure here on earth so a fire under these conditions would have been comparable with a fire on earth.

Turns out that's not true. Diluent (inert) gases like nitrogen or helium still carry away heat, so things burn more easily in a pure oxygen atmosphere than in air even when the partial pressures of oxygen are the same (which is what matters for respiration).

Somewhere on Youtube are videos of the US Navy's Sealab experiments in saturation diving performed in the 1960s. In one clip the divers try to light matches without success. Although the partial pressure of oxygen was roughly the same as sea level air, all that helium carried away heat so quickly that the match couldn't reach and stay at ignition temperature.

OTOH, the fire hazard probably would have been somewhat less in zero g because convection wouldn't remove the combustion products and bring in fresh oxygen. There have been combustion experiments on Mir, Shuttle and/or ISS that demonstrate this.

[ka9q]

-no risk of decompression sickness in EVA or leak event

This was a big deal for Apollo, especially on the LM, because of the many EVAs. On Shuttle and ISS, which use ordinary sea level air, crews performing EVA must spend hours tediously preconditioning by breathing pure O₂ to flush the nitrogen out of their systems. Space suits still use pure O₂ at the lowest safe pressure because nobody has yet figured out how to make one that doesn't become intolerably stiff at 1 bar. Even at reduced pressure they're very fatiguing, especially in the hands and fingers.

[Rob48]

My understanding is that pure oxygen atmosphere was selected because:
-while in space, the only pressure inside the capsule was partial pressure of oxygen. This enabled lighter pressure vessel (=capsule) construction
-without nitrogen in capsule atmosphere, there was no need for heavy and cumbersome tankage, piping and regulator
-no risk of decompression sickness in EVA or leak event
-in microgravity there is no convection to carry combustion products away and bring fresh oxygen to fire, reducing fire hazard in orbit

The need for high pressure oxygen during ground testing rose from requirement of positive pressure inside the capsule to avoid contaminants entering. Because ECS produced only oxygen, they used it. Also there hadn't been any problems reported before. Soviets lost one cosmonaut on earth in low pressure, pure oxygen habitat but it was kept secret.

AFAIK the Apollo capsule should have been free of flammble materials but one by one flammable materials were installed inside for convenience's sake.

All those factors combined with go fever caused that nobody thought it was dangerous. Until one electrical fault arced... Sadly, the normalization of deviance seem to be part of human nature, especially under pressure. Eroding of O-rings or hits from insulation foam weren't  considered dangerous either, until the Challenger and Columbia disasters...

Lurky

I do understand the advantages of using pure O2, but still the idea of climbing into that environment with all its loose wiring etc seems incredible - especially as from what I have read, the Apollo 1 crew had highlighted frayed wires and other defects before the fire.

I saw a comment on another forum describing the Apollo 1 capsule as being essentially a bomb calorimeter. Slight hyperbole, but not a nice thought.