Moon landing

A Moon landing is the arrival of a spacecraft on the surface of the Moon.

These missions can be crewed, meaning humans are on board, or robotic, using uncrewed probes. Landing on the Moon is a massive scientific and engineering feat. It requires overcoming the gravity of both Earth and the Moon. Understanding how to land safely helps us explore the solar system.

To reach the Moon, a spacecraft must first leave Earth's gravity well. Currently, the only practical way to do this is by using a rocket. Unlike airplanes, rockets can continue to accelerate in the vacuum of space. As a spacecraft approaches the Moon, the Moon's gravity pulls it in. This causes the craft to increase in speed. To land without being destroyed, a spacecraft must decelerate.

There are two primary types of lunar landings: hard landings and soft landings. A hard landing is a high-speed impact where the spacecraft crashes into the surface. This can happen due to a malfunction or be done on purpose. For example, NASA crashed parts of the Saturn V rocket to create moonquakes. These moonquakes helped scientists map the internal structure of the Moon.

A soft landing is a controlled descent that results in little to no damage. This is the only method safe enough for human astronauts. To achieve this, spacecraft use braking rockets, also known as retrorockets. These rockets provide the delta-v, or change in velocity, needed to slow down.

The history of lunar exploration began with the Space Race in the late 1950s. Tensions between the United States and the Soviet Union drove rapid technological growth. The Soviet Union achieved the first hard landing with Luna 2 in 1959.

They also took the first pictures of the Moon's far side with Luna 3. The United States responded by creating NASA to lead civilian space efforts. In 1966, the Soviet Union achieved the first soft landing with Luna 9. The U.S. followed with several successful Surveyor missions.

Human exploration reached its peak during NASA's Apollo program. Apollo 11 was the first crewed mission to land in July 1969.

Neil Armstrong and Buzz Aldrin became the first humans to walk on the lunar surface. Between 1969 and 1972, there were six successful crewed landings. A total of twelve astronauts have walked on the Moon. Gene Cernan was the last person to step off the surface in December 1972.

These missions required massive rockets to carry the landing modules and the return ascent rockets.

Today, many nations and private companies are returning to the Moon. Only five nations have successfully achieved soft landings: the Soviet Union, the U.S., China, India, and Japan.

China's Chang'e program has landed four times since 2013. They even achieved the first landing on the far side of the Moon.

India's Chandrayaan-3 landed near the lunar south pole in 2023.

Japan's JAXA also joined the group with the SLIM lander in 2024. Commercial companies are also participating. Intuitive Machines' Odysseus became the first private spacecraft to land in 2024.

Firefly Aerospace's Blue Ghost later completed the first fully successful commercial landing.

Lunar missions are incredibly complex because of the physics involved. To return to Earth, a spacecraft must overcome the Moon's escape velocity. This requires a moon departure rocket to be carried all the way to the surface. This adds significant weight and size to the original launch vehicle. Once the craft reaches Earth, it must use heat shields and parachutes. These tools absorb kinetic energy to ensure a safe atmospheric entry. This cycle of launching, landing, and returning defines the challenge of lunar science.