All Hail The Felt-Tip Pen
When it was time to head back to Earth, Armstrong and Aldrin encountered a problem: an important circuit breaker malfunctioned, making it impossible to ignite the engine. Basically, their car broke down on the moon! Can you imagine how nerve-wracking that must have been?! After trying multiple repair techniques suggested by mission control, Aldrin tried the good ole fashioned "jam a felt-tip pen in the darn thing" approach. The makeshift switch worked, and the astronauts were able to rendezvous with Collins in the nick of time.