This bootprint marks one of the first steps human beings took on the moon in July 1969. It was made by American astronaut Buzz Aldrin during the Apollo 11 mission. Image Credit: NASA

Launch Date Jul. 16, 1969
Launch Site Cape Canaveral, Florida, USA | Launch Complex 39A
Destination Earth’s Moon
Type Orbiter, Lander, Sample Return (Human Crew)
Status Successful
Nation United States
Alternate Names N/A

Goals

Land astronauts on the Moon and return them safely to Earth.

Accomplishments

Conducted first crewed landing on the Moon, deployed instruments, took photographs, collected samples, and returned crew and samples safely to Earth.

Crew

Commander: Neil Armstrong

Lunar module (Eagle) Pilot: Edwin “Buzz” Aldrin, Jr.

Command module (Columbia) Pilot: Michael Collins

Key Dates

July 16, 1969: Launch

July 19, 1969: Lunar Orbit Insertion

July 20, 1969: Lunar Landing

July 21, 1969: Lunar Surface Departure

July 24, 1969: Recovery on Earth

In Depth

On 25 May 1961, six weeks after Soviet Cosmonaut Yuri Gagarin became the first person to fly into space and just 20 days after Alan Shepard became the first American to do so, President Kennedy declared a national goal of landing a man on the Moon and returning him safely to Earth by the end of the decade. A little more than eight years later, that feat was accomplished.

Apollo 11 Commander Neil A. Armstrong and Edwin E. "Buzz" Aldrin Jr., pilot of the lunar module “Eagle,” landed in Mare Tranquilitatis (the Sea of Tranquility) on 20 July 1969, while Michael Collins continued orbiting the Moon in the command module “Columbia.”

Descent to the Moon

The lunar module was very different from the command module, which would have to withstand the heat and stress of re-entry into Earth’s atmosphere. Walls as thin as a couple of sheets of printer paper were all that shielded the astronauts from the vacuum of space as they descended to the lunar surface. The floor of the crew compartment that the two men shared measured about 36 by 55 inches (91 by 140 centimeters). And since chairs were omitted to keep the weight down, the astronauts stood during both descent and ascent. They used harnesses augmented by handholds, arm rests and Velcro strips on the soles of their shoes to keep from bouncing around the cabin.

This first human landing on the Moon did not go smoothly. The descent was punctuated by a series of alarms caused by radar-tracking problems and computer overload. Armstrong overrode the automatic landing system when the astronauts saw that it was taking them to a dangerously rocky region. The fuel gauge read disturbingly low and dust, which the rocket engine blasted off the ground, obscured their view. But they touched down safely at 20:17 UT (4:17 p.m. EDT). Armstrong, with his heart racing at 150 beats per minute instead of his usual 60, coolly radioed the message, "Houston, Tranquility Base here. The Eagle has landed."

The astronauts immediately prepared the spacecraft to lift off and return to orbit. They needed to be ready to leave quickly if one of the lunar module’s footpads began to sink into the dust, a fuel tank on the ascent stage appeared damaged, or some other emergency arose.

One Small Step

Armstrong stepped onto the lunar surface at 02:56 UT on 21 July (10:56 p.m. EDT on 20 July) with the words, "That's one small step for (a) man, one giant leap for mankind." Aldrin followed 19 minutes later.

They deployed the Early Apollo Scientific Experiment Package (EASEP) and other instruments, unfurled a sheet of aluminum foil to trap solar-wind particles, took photographs and collected 47.51 pounds (21.55 kilograms) of lunar rock and soil, which included three minerals never seen before. They walked a total distance of about 820 feet (about 250 meters) and returned to Eagle, closing the latch at 5:11 UT.

Meanwhile, a drama was playing out in lunar orbit. The Soviet Union’s Luna 15, a robotic spacecraft launched three days before Apollo 11, was that country’s second attempt (following a failed launch the previous month) at a sample-return mission from the Moon. The Soviet spacecraft entered lunar orbit on 17 July, two days before Apollo 11 arrived. Though the American mission would be first to land people on the Moon, the Soviet mission might have been first to bring lunar samples back to Earth.

But Luna 15 remained in lunar orbit for four days while its controllers checked the onboard systems and performed two orbital maneuvers. When it fired its main retro-rocket to begin its landing, at 15:47 UT on 21 July, the American astronauts had completed their Moonwalk but would not begin their journey home for another two hours.

Four minutes into its descent, less than 2 miles (about 3 kilometers) above the lunar surface, the Soviet spacecraft stopped transmitting. It is thought to have crashed into the side of a mountain in Mare Crisium.

Return to Earth

Armstrong and Aldrin lifted off from the Moon at 17:54 UT on 21 July after 21 hours, 36 minutes on the lunar surface. The descent stage that had powered their soft landing served as a launch platform for the ascent stage that returned them to orbit. After they docked with Columbia and transferred into its crew compartment, they jettisoned Eagle into lunar orbit. It is assumed to have crashed into the lunar surface during the following one to four months.

Columbia splashed down in the Pacific Ocean on 24 July 1969 at 16:50:35 UT (12:50:35 p.m. EDT) after a mission elapsed time of 195 hours, 18 minutes, 35 seconds. The splashdown point was 400 miles SSW of Wake Island and 15 miles (24 kilometers) from the recovery ship USS Hornet. The primary mission goal of landing astronauts on the Moon and returning them to Earth had been achieved.

This had been the second space flight for each of the three astronauts. Armstrong, a civilian, had flown on Gemini 8; Aldrin was a USAF Colonel who had flown on Gemini 12; and Collins was a USAF Lt. Colonel who had flown on Gemini 10. The backup crew for Apollo 11 was Jim Lovell, Fred Haise, and William Anders. Command module Columbia is on display at the National Air and Space Museum in Washington, D.C.

Spacecraft

Launch Vehicle: Saturn V

Spacecraft Mass: 63,495 pounds (28,801 kilograms)

Lunar Surface Experiments:

Passive Seismic Experiment

Lunar Field Geology

Laser Ranging Retroreflector

Solar Wind Composition

Cosmic-Ray Detection (helmets)

Lunar Surface Close-Up (camera)

Lunar Sample Analysis

Additional Resources

NASA: Apollo 11

NASA: Apollo

NASA History Program Office: The Apollo Program

Apollo Lunar Surface Journal

Apollo Flight Journal

Apollo Expeditions to the Moon

Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions

Lunar and Planetary Institute: Apollo Missions

Apollo: Where Are They Now?

NASA Astronaut Biographies: Former Astronauts

Additional Images

https://www.nasa.gov/mission_pages/apollo/missions/apollo11.html

https://www.nasa.gov/apollo11-gallery

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