American astronauts successfully landed on the lunar surface exactly 6 times between 1969 and 1972. Each of these expeditions was part of the space program Apollo and required flawless operation of life support systems, navigation and propulsion systems. A total of 12 people visited the Earth's satellite, all of whom represented the United States of America. These flights remain the only example in human history of a manned visit to another celestial body.
The program included not only successful landings, but also critical tests such as the mission Apollo 13, which did not reach the target due to the explosion of the oxygen tank. Statistics show that out of nine manned flights to the Moon, six resulted in landings. Data on trajectories, fuel consumption and time spent on the surface are recorded in NASA archives and are available for verification. Below is a detailed analysis of each stage of the landing.
Chronology and number of successful missions
The history of manned missions to the Moon spans a short but eventful period in the late 1960s and early 1970s. The first successful landing occurred on July 20, 1969, when the module Apollo 11 touched the surface in the Sea of Tranquility. This event was the culmination of the arms race and technological rivalry between the superpowers. The subsequent five missions were conducted approximately six months apart, allowing engineers to analyze the data and make adjustments.
Each subsequent expedition became more difficult and longer than the previous one. If the first flight lasted about 2.5 hours on the surface, then the latest missions allowed astronauts to work outside the ship for more than 20 hours in total. Navigation systems of that time, although they were inferior to modern analogues in terms of computing power, they coped with the task of delivering the crew to a given point with high accuracy.
Technical details of landing
The Lunar Module landing system used a variable thrust engine, which allowed it to dampen the rate of vertical descent in vacuum and low gravity conditions.
It is important to note that between successful landings there were also unsuccessful attempts, which, however, did not interrupt the program. For example, mission Apollo 13 was supposed to be the third landing, but a technical malfunction caused the crew to return to Earth, going around the satellite. This proves that the risk of failure remained throughout the program, despite careful preparation.
List of Apollo surface landing missions
To understand in detail the scale of the operation, it is necessary to consider each of the six successful missions separately. They all used the same flight architecture: launch vehicle Saturn V, separation of the command and lunar modules, docking and return. However, the goals and results of each expedition varied significantly.
- 🚀 Apollo 11 - the first landing in history, crew: Neil Armstrong, Buzz Aldrin. It took place in the Sea of Tranquility area, the main task was to test the ability of a person to work in low gravity conditions.
- 🌑 Apollo 12 - second landing, known for precise landing next to the device Surveyor 3. Crew: Charles Conrad, Alan Bean. The astronauts collected parts from the automatic station.
- ⚠️ Apollo 14 - first landing after the Apollo 13 accident. Crew: Alan Shepard, Edgar Mitchell. Known for using a cart to transport equipment and playing golf.
- 🛰️ Apollo 15 - the first of the "J-missions" with increased duration. Crew: David Scott, James Irwin. First used Lunokhod (Lunar Roving Vehicle), which expanded the research radius.
- 🌋 Apollo 16 - landing in mountainous areas. Crew: John Young, Charles Duke. The main focus was on geological research and collection of regolith samples.
- 🏁 Apollo 17 - the last manned landing to date. Crew: Eugene Cernan, Harrison Schmitt. The only geologist on the Moon and the record holder for the longest stay on the surface.
The table below shows comparative characteristics of surface duration and number of extravehicular activity (EVA) completed for each mission.
| Mission | Year | Duration on surface | Number of outputs (EVA) | Collected load (kg) |
|---|---|---|---|---|
| Apollo 11 | 1969 | 21 h 36 min | 1 (2 hours 31 minutes) | 21.55 |
| Apollo 12 | 1969 | 32 h 47 min | 2 (3 hours 56 minutes) | 34.35 |
| Apollo 14 | 1971 | 33 hours 31 minutes | 2 (9 hours 23 minutes) | 42.80 |
| Apollo 15 | 1971 | 66 h 55 min | 3 (18 hours 35 minutes) | 77.32 |
| Apollo 17 | 1972 | 74 h 59 min | 3 (22 h 04 min) | 110.40 |
Technical aspects of landing and take-off
The process of landing on the Moon was the most critical stage of the flight. The lunar module, consisting of landing and takeoff stages, had to absorb the enormous orbital speed. The landing stage engine ran on hypergolic fuel, which ignites when components come into contact, eliminating the need for an ignition system. This increased reliability, but required precise traction control.
After completing work on the surface, the astronauts used the top of the module to return to orbit. Take-off stage engine had to work perfectly the first time since there was no backup engine. An error in calculations or equipment failure meant the death of the crew. Statistics confirm 100% reliability of these engines in all six successful missions.
⚠️ Attention: In the lunar vacuum, the lack of atmosphere precluded the use of parachutes for braking. All kinetic energy was extinguished solely by the operation of jet engines.
Navigation systems relied on on-board computers and radio communications with the Earth. Computer Apollo Guidance Computer had less power than modern calculators, but its software was written with the highest fault tolerance in mind. The astronauts also had the opportunity to switch to manual control in case of automatic failure, which happened partially during landing Apollo 11 due to rocks at the landing site.
☑️ Critical landing systems
Scientific results and collected samples
The main purpose of the landings was not only political prestige, but also to obtain new scientific data. The astronauts installed recording instruments on the surface seismic activity, measuring heat flow from the subsurface and tracking the solar wind. These data made it possible to compile the first detailed map of the internal structure of the satellite.
In total, the crews of six missions delivered 382 kilograms of lunar soil and rocks to Earth. The samples were collected in special containers that maintained a vacuum to prevent contact with the Earth's atmosphere before reaching the laboratory. The analysis showed the absence of water in the minerals and the presence of isotopes characteristic of the bombardment of the surface by cosmic rays over billions of years.
Of particular interest are the samples collected during the mission Apollo 17 in the Taurus-Littrow Valley. The famous orange soil was found there, the color of which was given by microscopic glass beads of volcanic origin. This was evidence of past volcanic activity on the Moon, which changed the understanding of its geological history.
Research Tip: Lunar regolith is extremely abrasive and sticks to spacesuits due to static electricity, which made it difficult to seal the airlocks when returning to the module.
Myths and conspiracy theories around the landings
Despite the huge amount of documentary evidence, the topic of the landings has given rise to many conspiracy theories. Critics point to the waving flag, lack of stars in the photos and shadows of varying lengths. However, all these phenomena have a clear physical explanation, confirmed by experiments and calculations.
The flag “fluttered” only at the moment of installation due to the inertia of movement and the presence of a horizontal crossbar, since in a vacuum it would simply hang. The absence of stars in the photographs is explained by the camera's exposure settings: the bright surface of the Moon and the white spacesuits required a short shutter speed, which is why dim stars were not included in the frame. The shadows were distorted by the uneven terrain.
⚠️ Attention: Independent observers, including the USSR, which carried out dense radio monitoring, did not detect any falsification of signals. Soviet specialists confirmed receipt of telemetry and samples.
Additional evidence comes from laser reflectors installed by astronauts on the surface. Observatories around the world still use them to accurately measure the distance to the Moon. If there had been no landings, these devices could not have been there, since the automatic stations of that time did not have the accuracy of installing such devices.
Why the landings stopped and plans for the future
After 1972, manned flights to the Moon ceased. The main reason was the colossal cost of the program Apollo, which in some years absorbed up to 4% of the US budget. With the end of the acute phase of the Cold War and the achievement of the main political goal - getting ahead of the USSR - the interest of Congress and society in expensive expeditions faded.
Instead of continuing the lunar program, attention was switched to the creation of orbital stations Skylab and programs Space Shuttle. Technologies developed for Apollo formed the basis for subsequent space exploration, but the flag-stomp-return format itself was deemed economically infeasible without the creation of a permanent infrastructure.
Now the situation is changing. Program Artemis The goal is not just a short-term visit, but the creation of a permanent base and the use of local resources. The next American astronauts, including the first woman, are planned to visit the Moon on new missions using reusable systems and international cooperation.
Main conclusion: The six successful Apollo landings remain the only confirmed fact of human presence on another celestial body, and not a single country in the world disputed these data at the time of their occurrence.
How many people have walked on the moon?
In total, 12 people visited the surface of the Moon. All were American men and participants in the Apollo program between 1969 and 1972. None of them ever returned to the satellite.
Is it true that the USSR also flew to the moon?
The Soviet Union sent only automatic stations to the Moon (Luna series), which delivered soil and launched lunar rovers. The N-1L3 manned program was not completed successfully due to problems with the N-1 launch vehicle.
Which mission took the longest?
The record holder is the Apollo 17 mission. The crew spent more than 74 hours on the surface, performed three spacewalks with a total duration of 22 hours and collected a record number of soil samples.
What happened to the lunar modules after takeoff?
The take-off stages were reset after docking with the command module and crew transfer. Most of them fell on the Moon, causing artificial moonquakes, which were recorded by seismometers. Only the Apollo 13 module burned up in the Earth's atmosphere.