Before revision: After the Apollo program, the United States used standard air-like cabin atmospheres for Skylab, 0.3 atm air-like : the Space Shuttle orbiter, and the International Space Station.1 atm Mechanics Piston-engine aircraft cabin pressurization using a dedicated compressor.
After revision: After the Apollo program, the United States used "a 74-percent oxygen and 26-percent nitrogen breathing mixture" at for Skylab, and a standard air-like cabin atmosphere the Space Shuttle orbiter, and the International Space Station.1 atm Mechanics Piston-engine aircraft cabin pressurization using a dedicated compressor.