Wednesday, January 27, 2010

43 Years Ago Today

Virgil "Gus" Grissom, Edward White and Roger Chafee were killed in the Apollo 204 fire.

The fire was entirely avoidable. NASA used pure oxygen in the Mercury, Gemini and Apollo spacecraft because the spacecraft didn't need to be as robust (3 or so psi cabin pressure over 14.7psi for an oxygen-nitrogen atmosphere) and they only needed to carry oxygen as a breathing gas, saving weight. The all-up test on January 27, 1967 was conducted with the astronauts in full gear and, because the capsule wasn't built to keep pressure out, the capsule was pressurized to 16 psi with pure oxygen.

Anyone familiar with how well fire burns in a pure oxygen environment would have been horrified. The Soviet space program, not known then as a model of safety, used regular air for pressurizing their spacecraft because of the fire hazard. Add to that the point that NASA was more concerned about an astronaut blowing out the hatch by accident than a requirement for easy escape, so the hatch could not be opened quickly. Finally, in violation of every known tenet of emergency egress design, the hatch opened inward.

There was a spark. A fire erupted. The three astronauts were incinerated inside the capsule. The Apollo program was set back over 18 months for a redesign of the capsule.

4 comments:

  1. The Soviets learned their oxygen fire accident in 1961, killing cosmonaut in training Valentin Bondarenko. A fire erupted in a low pressure, minimum 50% oxygen test chamber, after he had swabbed his skin with alcohol, having just removed multiple test sensors. An alcohol soaked cotton ball he tossed away landed on a hotplate, and poof... painful way to go. A crater on the moon's far side is named for him.

    Source: wikipedia

    ReplyDelete
  2. I was an AF lieutenant at the time, and that night I was my organization's OD. A four-star called me around 2 AM and said get on the phone to your CO RIGHT NOW and tell him I'm ordering all human tests in an O2 atmosphere to stop RIGHT NOW.

    Roger Chaffee was a classmate of mine in grad school...I give all my students a presentation on "Ethics and Competence in Engineering", and he's part of it.

    ReplyDelete
  3. I remember reading something frightening about pure oxygen under that pressure. It sounds silly, but it said *aluminum* burns in those conditions.

    ReplyDelete
  4. In 1968 while in AFROTC at the University of Colorado, our chapter of the Arnold Air Soceity dedicated our cadet lounge to "Gus" Grissom. How ironic it is that our President at that time was Ellison Onazuka.

    ReplyDelete

House Rules #1, #2 and #6 apply to all comments. Rule #3 also applies to political comments.

In short, don't be a jackass. THIS MEANS YOU!
If you never see your comments posted, see Rule #7.

All comments must be on point and address either the points raised in the blog post or points raised by commenters in response.
Any comments that drift off onto other topics are subject to deletion.

(Please don't feed the trolls.)

中國詞不評論,冒抹除的風險。僅英語。

COMMENT MODERATION IS IN EFFECT UFN. This means that if you are an insulting dick, nobody will ever see it.