This week we are celebrating the First Men On the Moon

On July 20, 1969, Apollo 11 astronauts Neil Armstrong and Buzz Aldrin became the first men to set foot on the moon.

“One Giant Leap for Mankind”

The Apollo 11 spacecraft took off from Kennedy Space Center on 9:32 a.m. EDT on July 16 with Neil Armstrong, Edwin “Buzz” Aldrin Jr. and Michael Collins on board. Soon after reaching lunar orbit about 76 hours into the mission, Armstrong and Aldrin entered the lunar module, the Eagle, and separated from the command module, the Columbia.

Armstrong guided the Eagle onto the moon’s surface, but not without trouble. The module’s computer erroneously sounded alarms and just 30 seconds worth of fuel was left when it touched down on the Sea of Tranquility at 4:18 p.m. on July 20, according to NASA.

“Houston, Tranquility Base here,” Armstrong radioed. “The Eagle has landed.”

Hours later, at 10:56 p.m., Armstrong took the first steps out onto the moon’s surface. “The ghostly, white-clad figure slowly descended the ladder. … Then he extended his left foot, cautiously, tentatively, as if testing water in a pool—and, in fact, testing a wholly new environment for man,” wrote Time. “That groping foot, encased in a heavy multi-layered boot (size 9½B), would remain indelible in the minds of millions who watched it on TV, and a symbol of man's determination to step—and forever keep stepping—toward the unknown.”

“That's one small step for a man,” said Armstrong, “one giant leap for mankind.”

Aldrin joined Armstrong minutes later, and the two conducted several operations over the next two and a half hours, collecting rock samples and performing tests on the solar wind. They also planted an American flag on the lunar surface, left a patch honoring the Apollo 1 crew, and left a plaque commemorating Apollo 11 mission.

They then rejoined Collins in the Columbia and returned to Earth, arriving on July 24 in Hawaii.

In a post-flight press conference, Armstrong calls the flight "a beginning of a new age," while Collins talks about future journeys to Mars.

Over the next three and a half years, 10 astronauts will follow in their footsteps. Gene Cernan, commander of the last Apollo mission leaves the lunar surface with these words: "We leave as we came and, god willing, as we shall return, with peace, and hope for all mankind."

The bootprints of Apollo are waiting for company.