On January 4, 1970, NASA cancelled the Apollo 20 moon mission.
This came just six months after Apollo 11 astronauts Buzz Aldrin and Neil Armstrong became the first people to ever set foot on the moon. Instead of launching another crew of astronauts to the moon, NASA decided to use the Saturn V rocket that was built for Apollo 20 to launch the Skylab space station instead. Budget cuts along with the nearly fatal disaster that happened with Apollo 13 led NASA to eventually cut two more Apollo missions. Canceling these missions also freed up resources for the space shuttle program.
