Lunar lander facts for kids
A lunar lander or Moon lander is a special spacecraft made to land on the Moon's surface. As of 2023, the Apollo Lunar Module is the only lander that has carried humans to the Moon. It made six successful landings between 1969 and 1972 during the U.S. Apollo Program. Many robotic landers have also reached the Moon, and some have even brought samples back to Earth.
Designing these landers is tricky. Engineers must consider the weight they carry, how much fuel they need, and how long the mission will last. If humans are on board, a life support system is also very important. The Moon has strong gravity but no air. This means landers cannot use parachutes to slow down. Instead, they must use their powerful engines to slow down and make a soft landing.
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History of Moon Landings
Over the years, many countries and organizations have tried to land on the Moon. Some attempts were successful, while others faced challenges.
Early Moon Missions (1958-1976)
The Luna program was a series of robotic missions by the Soviet Union. These missions included probes that crashed, flew by, orbited, and landed on the Moon. Luna 9 was the first spacecraft to make a soft landing on the Moon. This happened on February 3, 1966, after 11 earlier tries failed. Three Luna spacecraft later brought Moon soil samples back to Earth. Two other Luna spacecraft landed Lunokhod robotic rovers in 1970 and 1973. In total, the Luna program had seven successful soft landings out of 27 attempts.
The U.S. Surveyor program also aimed for soft landings. Surveyor 1 landed successfully on June 2, 1966. Four more successful landings followed, with the last one on January 10, 1968. The Surveyor program achieved five successful soft landings out of seven attempts.
The Apollo Lunar Module was the lander used by the U.S. Apollo program. As of 2022, it is the only lander that has carried humans to the Moon. The Apollo program made six successful human landings between 1969 and 1972. A seventh landing attempt, Apollo 13, was stopped when its oxygen tanks exploded.
The LK lunar module was the Soviet Union's lander for their own human Moon missions. Several LK modules were tested in orbit around Earth without a crew. However, the LK never flew to the Moon. This was because the N1 Rocket needed for the flight had many problems, including launch failures. After the U.S. landed humans on the Moon, the Soviet Union canceled both the N1 Rocket and the LK Lunar Module programs.
Recent Moon Missions (2013-2023)
The Chinese Lunar Exploration Program (also called the Chang'e project) includes robotic landers, rovers, and sample-return missions. Chang'e 3 made China's first successful soft landing on December 14, 2013. As of 2023, China has had three successful soft landings out of three attempts: Chang'e 3, Chang'e 4, and Chang'e 5. Chang'e 4 made history by being the first mission to land on the far side of the Moon.
Israel's SpaceIL tried to land its robotic Beresheet lander on April 4, 2019, but it failed. SpaceIL plans another attempt with a new lander called Beresheet 2.
India's Chandrayaan Programme had an unsuccessful robotic landing attempt on September 6, 2019, with its Chandrayaan-2 spacecraft. The lander crashed on the Moon. However, on August 23, 2023, their next lander, Chandrayaan-3, made India's first successful robotic soft landing.
Japan's ispace tried to land its Hakuto-R Mission 1 robotic lander on April 25, 2023. This attempt also failed, and the lander crashed. The company plans another landing attempt in 2024.
Russia's Luna-Glob program, which continues the Soviet Luna program, launched the Luna 25 lander on August 10, 2023. It was supposed to land near the Moon's south pole. But on August 19, 2023, the lander crashed on the Moon's surface.
Japan's Smart Lander for Investigating Moon (SLIM) launched on September 6, 2023. This probe will try to land on January 19, 2024, near the Shioli crater. It carries two small rovers.
Future Moon Missions (2024-Present)
On January 8, 2024, the first mission of NASA's CLPS program, Peregrine Mission One, was launched. This mission's lander was supposed to try a Moon landing on February 23, 2024. However, a fuel leak was found hours after launch. This means the lander will likely not reach the Moon or attempt a landing.
Moon Landing Success Rates
This table shows how many lunar soft-landing attempts have been made and how many were successful. It includes both robotic and human missions. "Landing attempt" means any mission launched with the goal of landing on the Moon, even if it failed to reach the Moon's orbit.
| Program | Country/Organization | Type | Landing attempts | Soft-landed | Outcome pending | Notes |
|---|---|---|---|---|---|---|
| Luna |  USSR |
robotic | 27 | 7 | This program is historical. Russia's Luna 25 (2023) is part of a new program. | |
| Surveyor |  NASA |
robotic | 7 | 5 | This program is historical. | |
| Apollo | NASA |
crewed | 7 | 6 | This program is historical. | |
| Soviet crewed lunar programs | USSR |
crewed | 0 | 0 | These programs are historical. Three uncrewed LK lunar landers were tested in Earth orbit. | |
| Chang'e |  CNSA |
robotic | 3 | 3 | Includes landers, rovers, and missions to bring samples back. | |
| Chandrayaan |  ISRO |
robotic | 2 | 1 | ||
| Beresheet |  spaceIL |
robotic | 1 | 0 | ||
| Hakuto-R |  ispace |
robotic | 1 | 0 | ||
| Luna-Glob |  Roscosmos |
robotic | 1 | 0 | This program continues the Soviet Luna programme. | |
| JAXA programs | JAXA |
robotic | 1 | 0 | 1 | Pending landing attempt by SLIM (January 19, 2024). |
| CLPS | NASA |
robotic | 1 | 0 | CLPS-1 Peregrine lander had a spacecraft failure. |
Challenges of Landing on the Moon
Landing on the Moon is very difficult. It has unique challenges compared to landing on other planets or moons.
No Atmosphere
The Moon has no air, unlike Earth, Mars, Venus, or Saturn's moon Titan. On planets with air, spacecraft can use parachutes to slow down. This saves a lot of fuel. For example, the Curiosity rover landed on Mars using parachutes, which meant it needed less fuel. A Moon lander, however, must carry all the fuel it needs to slow down using only its rockets. On the bright side, no atmosphere means a Moon lander doesn't need a heat shield or a special aerodynamic shape.
Strong Gravity
Even though the Moon's gravity is less than Earth's, it's still quite strong. It's much stronger than the gravity of small asteroids or comets. Because of this strong pull, landers need a lot of rocket power and fuel to slow down enough for a soft landing. For the Apollo program, keeping the lander's weight low was very important. More weight means more fuel is needed to land and take off from the Moon.
Extreme Temperatures
The Moon's temperature changes a lot because its day and night are very long. A lunar day lasts about 14 Earth days, and a lunar night also lasts about 14 Earth days. Temperatures can swing from around -250°F (-157°C) during the night to 250°F (121°C) during the day.
Lander instruments usually need to stay between -40°F (-40°C) and 120°F (49°C). For humans, the temperature needs to be even more controlled, around 68-75°F (20-24°C). This means landers must have strong heating and cooling systems. Because lunar nights are so long, solar power isn't enough to keep instruments warm. So, nuclear heaters are often used.
How a Moon Landing Happens
The main goal of any lunar lander is to achieve a soft landing. This is what makes a lander different from an "impactor," which just crashes into the surface.
All lunar landers need rocket engines to slow down. When orbiting the Moon, a spacecraft can travel over 1,500 meters per second (about 3,350 miles per hour). In the vacuum of space, rockets are the only way to slow down from such high speeds.
The landing process usually includes these steps:
- Descent orbit insertion: The spacecraft moves into an orbit that is good for the final descent. Early missions didn't do this; they just headed straight for the Moon.
- Descent and braking: The spacecraft fires its engines to slow down. If the engines stopped, the spacecraft would crash. During this step, the engines work hard to reduce the overall speed.
- Final approach: The spacecraft is almost at the landing spot. Small adjustments are made to land in the exact right place.
- Touchdown: The spacecraft successfully makes a soft landing on the Moon.
The Final Touchdown
Lunar landings usually end with the engine turning off a few feet above the Moon's surface. This is done to prevent the engine exhaust from kicking up Moon dust (called regolith) back onto the spacecraft. Engineers design the lander to be strong enough to handle this short fall without damage.
The first soft Moon landing was by the Soviet Luna 9 probe. It slowed down, then released a part with scientific tools. This part landed safely using airbags, which cushioned its fall. Luna 13 used a similar method.
However, airbags are not always used. For example, NASA's Surveyor 1 probe, which landed around the same time as Luna 9, did not use airbags. After slowing down to 3.4 meters (11 feet) above the surface, it simply fell. The spacecraft had special parts designed to absorb the impact and keep the instruments safe. More recently, China's Chang'e 3 lander used a similar method, falling 4 meters (13 feet) after its engine shut off.
The famous Apollo Program lunar landers were very strong. They could handle a drop even if their engines cut out up to 10 feet (3 meters) above the surface. The landing gear was designed to absorb the shock. During Apollo 11, Neil Armstrong kept the engine firing until touchdown for a very gentle landing. Some later Apollo crews turned off the engine before touching down and felt a noticeable bump.
See also
- List of artificial objects on the Moon, a list of objects that have been left, landed, or crashed on the Moon
- List of crewed lunar lander designs
- Lunar module
