Apollo 11: First Steps on the Moon

On July 16, 1969, a towering 111-meter Saturn V launch vehicle lifted off from Launch Complex 39A at Kennedy Space Center, propelling Apollo 11 Commander Neil Armstrong, Command Module Pilot Michael Collins, and Lunar Module Pilot Buzz Aldrin toward the Moon. Generating 34.5 million newtons of thrust in its first stage, the Saturn V placed the spacecraft onto a translunar trajectory spanning 384,400 kilometers across cislunar space.

On July 20, 1969, Armstrong and Aldrin undocked the Lunar Module Eagle from the Command Module Columbia and initiated powered descent toward Mare Tranquillitatis (the Sea of Tranquility). Despite 1201 and 1202 guidance computer program alarms and a boulder-strewn crater along the automated landing target, Armstrong manually piloted Eagle to a safe touchdown with less than 30 seconds of descent fuel remaining. Hours later, Armstrong stepped onto the lunar regolith, declaring: 'That's one small step for [a] man, one giant leap for mankind.'

During their 21 hours and 36 minutes on the lunar surface, the crew deployed the Early Apollo Scientific Experiments Package—including a passive seismometer and a laser ranging retroreflector still used by astronomers today—and collected 21.55 kilograms of lunar basalts and breccias. Radiometric dating of these samples revealed the Moon's ancient volcanic crust and revolutionized planetary formation theory.