 Its ability to resist atomic oxygen exposure means it is commonly used as the outer-most layer of multi-layer insulation for space; it was used on the Space Shuttle and the International Space Station.It was incorporated into NASA space suits after the deadly 1967 Apollo 1 launch pad fire, in which the astronauts' nylon suits burned through.After the fire, NASA demanded any potentially flammable materials be removed from both the spacecraft and space suits.