Two astronauts walked on the Moon during Apollo 11: Neil Armstrong and Edwin “Buzz” Aldrin. The third crew member, Michael Collins, remained in lunar orbit aboard the command module Columbia.
Apollo 11 launched from Kennedy Space Center in Florida on July 16, 1969, atop a Saturn V rocket. Armstrong and Aldrin landed the lunar module Eagle in the Sea of Tranquility on July 20, while Collins continued circling the Moon and managed the spacecraft that would bring all three astronauts home.
Armstrong stepped onto the lunar surface first, followed by Aldrin. Their combined moonwalk lasted about two and a half hours, during which they photographed the site, collected samples and deployed scientific instruments, including a seismometer and a laser-ranging reflector.
The number is easy to confuse because Apollo 11 had a three-person crew. Only two descended to the surface; Collins’s orbital role was essential to rendezvous with Eagle and complete the return journey. Apollo missions later put ten more astronauts on the Moon.