At this moment, fifty years ago, Virgil "Gus" Grissom, Edward White and Roger Chafee were burned to death in the Apollo 204 (or Apollo 1) fire. The fire was so intense that the astronauts were shrink-wrapped in their spacesuits.
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 for an oxygen-only atmosphere over 14.7psi for an oxygen-nitrogen atmosphere) and they only needed to carry oxygen as a breathing gas, saving weight.
The test fifty years ago was an "all-up" test, conducted with the astronauts in full gear. 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, but NASA seemed to have been completely oblivious to the risk. The Soviet space program, not known then as a model of safety, used regular air for pressurizing their spacecraft because they learned this lesson the hard way in 1961, when Valentin Bondarenko, one of the first group of pilots selected for the cosmonaut program, burned to death in an oxygen-rich environment during an endurance test.
NASA was more concerned about an astronaut blowing out the hatch by accident than a requirement for easy escape during an emergency, so the hatch could not be opened quickly. Finally, in violation of every known tenet of emergency egress design and despite the recommendations of the spacecraft's builder, the inner hatch door opened inward.
There was a spark. A fire erupted. The three astronauts had no chance at all.
The hatch itself is now on display.
It would by no means be the last time that NASA was overly complacent about safety risks.
We Also Learned About Assumptions Today!
49 minutes ago
3 comments:
Roger Chaffee was my classmate in grad school. Today all my engineering classes start with a first-day lecture on ethics & competence...
Engineers can focus on the wrong things, like RFP-manship and what do the specs require, not what the real world demands...
I worked on the Space Station power system during the design phase in the Systems Engineering group. We did the high-level specs and translations from the RFP down to usable requirements. One big item was if a system was life-critical, and the power system wasn't (at the time). It is 100% computer controlled so if the lights go out hard you can't just suit up and close a circuit breaker out at the power module.
I was in a meeting and asked how we would recover power in the event of a hard crash, and the rote response was it would be restarted from the attached Shuttle.... OK, what if there isn't a shuttle docked? The answer was shrugged shoulders.. I am a submariner, so safety and recoverability is second nature. When I pushed harder about restarting the power system I was finally told "it is't designated as life-critical, we don't have to worry about that". Well, I lost my temper and barked out the question if people had to die on orbit for them to realize power (for lights, air movement, CO2 removal, etc.) was a life-critical system...
I didn't make any friends but I think the designers took things a bit more seriously...
Cripes, I learned about what oxygen does when they taught me how to gas weld in high school. Maybe when you get that far along in technology and engineering, you sort of lose touch with the basics. That was my experience as a machinist, anyway.
I was only six when it happened, but as I really loved rockets at the time, I do still remember it well.
-Doug in Oakland
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