The first crewed Moon landing, hour by hour: the Saturn V launch, the descent to Tranquility Base, Armstrong's first step, the experiments left on the surface, and splashdown in the Pacific. All times shown are UTC.
At 13:32 UTC a 111-metre Saturn V — nearly 3,000 tonnes and still the most powerful rocket ever flown — climbed off Pad 39A on 7.6 million pounds of thrust. Commander Neil Armstrong, Buzz Aldrin and Michael Collins rode atop it. An estimated one million people watched from Florida's beaches and highways, and some 600 million more on television worldwide.
Two and a half hours after launch, over the Pacific, the Saturn V's third stage reignited for the Trans-Lunar Injection burn — flinging the spacecraft toward the Moon at about 39,000 km/h, fast enough to break free of Earth orbit. Collins then eased the command module Columbia away, turned it nose-about, and docked with the lunar module Eagle to pull it free of the spent rocket stage.
After a three-day coast, Apollo 11 slipped behind the Moon and fired its engine out of contact with Earth. Emerging into lunar orbit, the crew joined the tiny handful of humans ever to see the Moon's far side with their own eyes, and began photographing the Sea of Tranquility landing site sliding past 100 km below.
Armstrong and Aldrin floated into Eagle, undocked from Columbia, and slowly rotated so Collins could inspect the spidery lander for damage. "The Eagle has wings," Armstrong radioed. The two craft drifted apart, and for the first time the crew of three was split for the descent.
As Eagle dropped toward the surface, its guidance computer flashed "1202" and "1201" program alarms — it was overloaded with data. In Houston, 26-year-old controller Steve Bales made a split-second "GO" call, judging the alarms non-fatal. Realising the autopilot was steering them into a boulder-strewn crater, Armstrong took semi-manual control and flew on, hunting for smooth ground.
At 20:17 UTC Eagle settled onto the Sea of Tranquility with only about 25 seconds of landing fuel to spare. "Houston, Tranquility Base here — the Eagle has landed." The site sits at 0.674°N, 23.473°E on the Moon. A relieved Houston replied: "You've got a bunch of guys about to turn blue. We're breathing again."
At 02:56 UTC on 21 July, Armstrong climbed down the ladder, pressed his left boot into the grey dust and spoke: "That's one small step for a man, one giant leap for mankind." An estimated 650 million people — a fifth of humanity — watched the ghostly live broadcast. His first task was to scoop a "contingency sample," in case they had to leave in a hurry.
Nineteen minutes later Aldrin joined Armstrong on the surface, gazing at the airless, shadow-sharp landscape and calling it "magnificent desolation." The two moved in bouncing, low-gravity hops — the Moon's gravity is one-sixth of Earth's — as they learned to walk in stiff, pressurised suits.
The astronauts planted a specially stiffened U.S. flag, unveiled a plaque on Eagle's leg reading "We came in peace for all mankind," and took a phone call from President Nixon — "the most historic telephone call ever made." They set out three experiments: a seismometer, a solar-wind collector, and a laser retro-reflector that scientists still bounce lasers off today to measure the Earth–Moon distance to within centimetres.
While two men made history below, Michael Collins orbited alone in Columbia. Each time he passed behind the Moon he lost all radio contact with Earth and his crewmates — utterly cut off. "Not since Adam has any human known such solitude," noted Mission Control. Collins later said he felt not fear but a calm awareness of being, for those minutes, the most isolated human in history.
After about two hours and 31 minutes outside, the crew climbed back into Eagle with 21.5 kg of rock and soil. To save weight for lift-off they tossed out overshoes, cameras and tools — and left behind bootprints that, with no wind or water on the Moon, may survive for millions of years. Neither man slept well in the cold, cramped cabin.
At 17:54 UTC Eagle's ascent engine — which had no backup and had never been fired on the Moon — lit perfectly, blasting the upper stage off its descent platform. A nerve-wracking detail: hours earlier the astronauts had accidentally snapped off the engine's arming switch. Aldrin improvised, pushing the broken circuit breaker in with a felt-tip pen so they could get home.
Eagle rose to rejoin Columbia, and after a careful rendezvous the two craft docked. Armstrong and Aldrin transferred back with their precious samples, and the faithful Eagle was cast off — left to orbit the Moon before eventually crashing onto its surface at a spot never precisely found.
Behind the Moon once more, the crew fired the engine for Trans-Earth Injection, breaking free of lunar gravity for the two-and-a-half-day fall back to Earth. The hardest, most dangerous milestones were now behind them; ahead lay only the fiery re-entry.
At 16:50 UTC on 24 July, Columbia hit the North Pacific at about 13.3°N, 169.2°W, some 1,400 km southwest of Hawaii. The capsule flipped nose-down in the swell before three flotation bags inflated and righted it. Eight days, three hours and 18 minutes after launch, the voyage was over.
Navy frogmen from the USS Hornet reached the bobbing capsule and passed the crew biological isolation garments — a precaution against unknown "moon germs." President Nixon watched from the carrier as the three, now sealed inside a Mobile Quarantine Facility, peered out through its small window. They would spend 21 days in quarantine before the world could finally welcome them home.