Re: One of the things not tested
That was true IN SPACE and amounted to 2-4psi
However that wasn't true on the ground and that's the root cause of the Apollo 1 fire
The problem was that they were pressurised to 2-4psi over atmospheric pressure _with pure oxygen_ in order to verify the leak integrity of the capsule (16.7psi, according to the report, vs 14.7psi atmospheric)
Pure oxygen at 16-18psi makes velcro (nylon) essentially an explosive and there was a LOT of velcro in the cabin - apparently various engineers had been pleading for these tests not to be done in case there was a spark, or at least to reduce the amount of flammables in the cabin, whilst the astronauts themselves were worried about the quality of the wiring
It turned out that the netting used for the wiring harnesses was also made of nylon
Once the fire took hold and spread from the wiring harnesses to the cabin velcro, pressure inside the capsule ballooned due to combusion gasses plus temperature rise and the door essentially corked itself shut. Bolted or not, it wasn't openable without several tons of force - an opening force that the ground crew weren't able to provide
https://aapt.scitation.org/doi/10.1119/1.5095379 - "The Apollo 1 Fire: A Case Study in the Flammability of Fabrics"
https://arstechnica.com/science/2017/01/the-hell-of-apollo-1-pure-oxygen-a-single-spark-and-death-in-17-seconds/
Biting the hand that feeds IT
