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.
Estimates put about a million people along the roads, beaches and causeways around Cape Kennedy on the morning of the launch, and roughly 3,500 accredited reporters inside the press site. Former president Lyndon Johnson watched from the stands. The countdown ran without a hold.
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.
On the third day out the crew opened a colour television broadcast from about 175,000 miles from Earth, moved the camera through the tunnel into the lunar module, and showed the checklists and the equipment they would use to land. It ran a little over half an hour. Nobody had seen the inside of a spacecraft on the way to the Moon before.
The burn that put Apollo 11 into lunar orbit had to be made on the far side, which meant it happened with no radio contact and no way for Houston to help. The crew went behind the Moon, ran the engine for just under six minutes, and the only proof it had worked was whether they came out the other side on the expected schedule. They did.
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 pitchover the landing site came into view and it was a boulder field on the edge of a crater. Armstrong switched to the semi-manual mode, held the descent rate himself and flew on past it looking for flat ground. The Eagle came down roughly four miles beyond the point the computer had been aiming for.
Charlie Duke read the propellant calls up from Houston in the last two minutes. The numbers were not the time until the tanks ran dry. They were the time left before the crew had to either be on the ground or abort back to orbit, and the margin built into them was thin. Armstrong landed with the 30-second call already made.
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."
Before the walk, Aldrin took bread and a small chalice of wine from a kit he had carried up, and read to himself from the Gospel of John. He was an elder at Webster Presbyterian Church in Texas. He did not describe it on the air: NASA was being sued over the Genesis reading from Apollo 8 and had asked the crew to keep religious observance private. The flight plan had a rest period between landing and the moonwalk. Neither man wanted it, and Houston agreed to move the walk forward.
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.
They collected 21.5 kg of rock and soil, most of it in the last half hour, and set out the Early Apollo Scientific Experiments Package: a passive seismometer, a foil sheet to catch solar wind particles, and a panel of 100 quartz prisms. Observatories still bounce lasers off that panel to measure the distance to the Moon.
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.
A circuit breaker for the ascent engine had snapped off, probably caught by a backpack in a cabin with no spare room. There was no replacement part on board. Aldrin pushed the plastic tip of a felt-tip pen into the slot and closed the circuit with it. The engine lit on time.
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.