The Apollo 11 crew spent twenty-one hours on the Moon before leaving to return home to Earth, which meant crew members relied on their Moon suits to keep them alive and well while carrying out their mission. According to this NASA press release prior to the mission, Moon suits were built not only to protect crew members from potentially hazardous materials and conditions from the Moon’s atmosphere and chemical composition but also to function as a “one-man spacecraft,” supplying them with oxygen for up to 4.5 hours, cooling, pressurization, water, communications systems, and more!

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Images courtesy of the Denault Space Program papers, MG 111