Video courtesy of NASA Johnson

But before touching down in the lunar lander, the astronauts — along with nearly every astronaut in the Mercury, Gemini, Apollo, Skylab and Apollo-Soyuz programs — studied the stars at the Morehead Planetarium at UNC‑Chapel Hill (moreheadplanetarium.org). Between 1959 and 1975 (when computer navigation became more reliable), astronauts used specially-built equipment to simulate navigating space using the stars as their guide.

This celestial know-how saved lives more than once: on at least three missions, electrical failures knocked navigational equipment offline, leaving astronauts looking to the heavens for guidance.