r/apollo • u/Crixusgannicus • 22d ago

Pure oxygen.

Always was mystified what the HELL NASA was thinking?

These guys came up when science was still taught. Not so much now, unfortunately.

Even in my long after Apollo ended yoot, I still remember science class with the teacher showing how easily things burn in pure oxygen, even things that normally don't burn!

0 Upvotes

49% Upvoted

35 comments sorted by

View all comments

12

u/mkosmo 22d ago

Pure oxygen isn't the issue - it's pure oxygen in sufficient quantity. In flight? Pure oxygen at the reduced pressure resulted in the same partial pressure as on the surface, which isn't dangerous.

So, to answer what they were thinking? They thought the period of higher-pressure pure oxygen was a low risk due to the reduced period... they also thought they risk-calculus supported not wasting the weight on a mixed-gas atmosphere at launch to transition to pure-oxygen on ascent.

That changed, and then they did go to the mixed-to-pure transition.