Returning to Earth
To leave the Moon in the early hours of July 21, Armstrong and Aldrin used the descent stage of the lunar module as a launchpad. Squeezed inside the upper ascent stage, the two astronauts blasted off and successfully rejoined Michael Collins in Columbia. The lunar module was then discarded, and a blast from a rocket in the service module sent the astronauts on their homeward course.
Before reentering Earth’s atmosphere, the astronauts seated themselves inside the cone-shaped command module. This was the only part of the Apollo
spacecraft with tough, outer insulating layers. The insulation would shield the crew from the searing heat, caused by air friction, that makes a spacecraft glow red-hot as it plunges back into the atmosphere.
The command module carried three large parachutes that opened during the final stage of descent, dropping the spacecraft safely into the Pacific Ocean. Apollo 11 splashed down on July 24,
1969. The astronauts, hailed as heroes, received a huge welcome. First, however, they had to spend more than two weeks in isolation in a sealed medical chamber in case they had brought back any harmful infections from space. Fortunately doctors found none.