Apollo 1 caught fire 47 years ago today

[LongTomH]

[riqster]

1. Godspeed the crew of Apollo 1

[AAO]

2. How in the world did they get the idea

that a cabin bathed in pure oxygen was a good idea? I still after all these years don't understand how that was allowed to go forward.

[DreamGypsy]

3. Here's some information on the pure oxygen atmosphere...

from Wikipedia: Pure oxygen atmosphere

The plugs-out test had been run to simulate the launch procedure, with the cabin pressurized with pure oxygen at the nominal pre-launch level of 16.7 psi (1.15 bar), 2 psi above standard sea level atmospheric pressure. This is more than five times the 3 psi partial pressure of oxygen in the atmosphere, and provides an environment in which materials not normally considered highly flammable will burst into flame.

The high-pressure oxygen atmosphere was consistent with that used in the Mercury and Gemini programs. The pressure before launch was deliberately greater than ambient in order to drive out the nitrogen-containing air and replace it with pure oxygen. After liftoff, the pressure would have been reduced to the in-flight level of 5 psi (0.34 bar), providing sufficient oxygen for the astronauts to breathe while reducing the fire risk. The Apollo 1 crew had tested this procedure with their spacecraft in the Operations and Checkout Building altitude (vacuum) chamber on October 18 and 19, 1966, and the backup crew of Schirra, Eisele and Cunningham had repeated it on December 30.

When designing the Mercury spacecraft, NASA had considered using a nitrogen/oxygen mixture to reduce the fire risk near launch, but rejected it based on two considerations. First, nitrogen used with the in-flight pressure reduction carried the clear risk of decompression sickness (known as "the bends&quot . But the decision to eliminate the use of any gas but oxygen was crystallized when a serious accident occurred on April 21, 1960, in which McDonnell Aircraft test pilot G.B. North passed out and was seriously injured when testing a Mercury cabin / spacesuit atmosphere system in a vacuum chamber. The problem was found to be nitrogen-rich (oxygen-poor) air leaking from the cabin into his spacesuit feed. North American Aviation had suggested using an oxygen/nitrogen mixture for Apollo, but NASA overruled this. The pure oxygen design also carried the benefit of saving weight, by eliminating the need for nitrogen tanks.

In his monograph Project Apollo: The Tough Decisions, Deputy Administrator Seamans wrote that NASA's single worst mistake in engineering judgment was not to run a fire test on the Command Module prior to the plugs-out test. In the first episode of the 2009 BBC documentary series NASA: Triumph and Tragedy, Jim McDivitt said that NASA had no idea how a 100% oxygen atmosphere would influence burning. Similar remarks by other astronauts were expressed in the 2007 documentary film In the Shadow of the Moon.

From Wikipedia: Fire

The crew members were using the time to run through their checklist again, when a voltage transient was recorded at 6:30:54 (23:30:54 GMT). Ten seconds later (at 6:31:04), Chaffee exclaimed "Hey!", and scuffling sounds followed for two seconds. White then reported, "I've got a fire in the cockpit!". Some witnesses said that they saw White on the television monitors, reaching for the inner hatch release handle as flames in the cabin spread from left to right and licked the window. The final voice transmission is believed to have come from Chaffee. Six seconds after White's report of a "fire in the cockpit", a voice cried out, "There's a bad fire!". The sound of the spacecraft's hull rupturing was heard immediately afterward, followed by "I'm burning up!" and a scream. The transmission then ended abruptly at 6:31:21, only 17 seconds after the first report of fire. The cabin had ruptured due to rapidly expanding gases from the fire, which over-pressurized the Command Module to 29 psi (2.0 bar)

This close-up view of the interior of the Command Module shows the effects of the intense heat of the flash fire.

[Divernan]

4. We got a call at home telling us about the Apollo 1 fire before it was publicly announced.

(I posted this once already in another thread on the topic.)
My husband worked at Cape Canaveral on Grumman's Apollo Lunar Module - referred to as the LEM. He got a call at home around 7:30 p.m. telling him of the fire and that all 3 astronauts had died. They were unable to open the hatch because of excess cabin pressure and were pounding on the hatch and screaming for several minutes before they died. This account was confirmed for him by several men who witnessed this when he went into work at the Cape the next day. But the official NASA spin, trying to protect its funding, was: "The three astronauts died of asphyxiation. Their deaths were relatively quick and painless, their suits protecting them from the intense heat of the fire." I recall the various contractors at the Cape referred to NASA as standing for Never A Straight Answer.

Another bit of local lore - Grissom had been so unhappy with multiple problems with the Apollo and the inability of the engineers to adequately address them that he brought a lemon in from home and hung it on the rocket.

On January 22, 1967, Grissom made a brief stop at home before returning to the Cape. A citrus tree grew in their backyard with lemons on it as big as grapefruits. Gus yanked the largest lemon he could find off of the tree. Betty had no idea what he was up to and asked what he planned to do with the lemon. " 'I'm going to hang it on that spacecraft,' Gus said grimly and kissed her goodbye." (54) Betty knew that Gus would be unable to return home before the crew conducted the plugs out test on January 27, 1967. What she did not know was that January 22 would be "the last time he was here at the house".

http://www.hq.nasa.gov/office/pao/History/Apollo204/zorn/grissom.htm

Three brave men - Rest In Peace.

[Sand Wind]

5. To be an astronaut is a dangerous job

Heil to the heros !

[jimlup]

6. Wow yeah I remember that event too well...

I was an impressionable space-fanatic 10 year old kid. Ed White was my boyhood astronaut hero.

[SoapBox]

7. Oh my...

Shocking that it was that long ago...here's hoping we never forget.

[Nightjock]

8. God bless them

I was a little too young to remember, but the HBO series "From the Earth to the Moon" does an amazing episode on the tragedy. It was informative, made me cry and opened my eyes to truly appreciate those brave souls.

[Crunchy Frog]

9. NASA disasters always seem to happen on or near my birthday.