james ozzie
"The deadly Apollo 1 launch pad fire ended pure oxygen cabins"...Er, no it didn't, or at least not immediately - all the subsequent Apollo missions flew, manned, with pure Oxygen enviroments. What did stop post Apollo 1, amongst other things, was the procedure of pumping the Cabin up to greater than 15 psi with pure Oygen pre-launch ( Or in Apollo 1's case, a launch rehearsal). That, procedure, plus the uncontrolled spread/use of infalammable material in the Command Module (e.g. velcro), played a major part in the spread of the fire in Apollo 1.