After the tragic fire on Apollo 1, NASA engineers set about designing a less flammable atmosphere for the capsules. Here, Popular Science details the differing atmosphere compositions in the Gemini and Apollo modules, and in some spacecrafts that never made it off the drawing board. By cutting oxygen with other gases like nitrogen, NASA cut down on the risk of cabin fires.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.