Moon Landers

v0.2 - 25-04-2020

Moon landings

Earth's moon is a body that has no atmosphere. Therefore a parachute landing is by definition, impossible. These landings are quite complex as one needs a high amount of control over the rocket engines to perform a safe landing. This can be seen by the motor used on the Apollo Lunar Lander which could be throttled to between 10 and 60% of full thrust. Another moon where landing attempts were to be made is Phobos, one of the Martian moons. Phobos is much smaller than the earth-moon, making landings even more difficult. One could compare a landing on the Martian moons more to an asteroid lander. Landings on these surfaces can be found on separate pages. 


Luna Programme

Operator: Soviet space program

Target:  Moon

Landing date:  1959-1976

Status:  Retired


The Luna programme was a multi-billion two-decade-long programme that consisted of more than 40 launches, however, only 24 have official Luna numbers as the others failed to leave Earth's orbit. The programme achieved several "firsts", namely the first lunar impactor, the first lunar flyby, the first spacecraft to take a picture of the far side of the moon, the first soft landing, the first lunar orbiter, and lastly first circumlunar probe to return to earth. The programme was divided into 3 generations of spacecraft.

 

Luna 1-3

The first generation of spacecraft was Luna 1 through 3. Luna 1, intended as an impactor, missed the moon and was the first spacecraft to do a lunar flyby. Luna 1 released one kg of sodium gas in space making it visible and allowing it to be tracked by astronomers from the Earth. There was no propulsion on board and it was powered using mercury oxide batteries. It also discovered the existence of solar winds and the lack of a magnetic field on the moon. Luna 2 was similar to Luna 1 and was successful in impacting the moon. Luna 3 was a flyby mission that clicked 29 photos of the far side of the moon. Unfortunately, only 17 of those images could be transmitted back to Earth.


Luna 4-14

The second generation of spacecraft was Luna 4 through 14. Luna 4-8 were landers that failed at soft landing. Luna 8 completed the development of a star tracker and failed because a puncture in the airbag led to a landing failure. Luna 9 was the first successful lander on the moon. It also debunked the fear that the surface of the moon was too soft, and the lander would sink in.


Luna 10 was the first spacecraft to successfully orbit a planetary body other than Earth. The “Internationale” was broadcast from Luna 10 during its first orbit and played in front of the Twenty-third Congress of the Communist Party of the Soviet Union. Luna 11 was an orbiter who amongst other things tested the efficiency of lubricants for gear transmission in vacuum for future rover missions. Luna 13 was a lander which was very similar to Luna 9. It took panorama pictures that took 100 minutes to transfer each. Luna 14 was an orbiter to test communication systems in lunar orbit and earth and engineering test of gear transmission systems in a vacuum.


Luna 5-24

The third generations of spacecraft were Luna 15 through 24. Luna 15 was a sample return mission that took place at the same time as Apollo 11. It is suspected to be a last-ditch attempt at getting lunar samples back to Earth before the US. Unfortunately, the landing wasn't successful. Luna 16 was the first successful Soviet sample return mission. The lander had a drill and robotic arm to load the samples into the rocket. The spacecraft was able to drill to a depth of 35 cm before encountering hard rock. 101 grams of sample were returned to earth. There was no control system on the return rocket and there was only one burn to set it on the trajectory of Earth.


Luna 17 was the first successful rover mission by the Soviet Union. Rover Lunokhod 1 used solar cells for power, travelled more than 10 km and lasted 11 days. It sent over 20000 pictures and 200 panoramas. Luna 19 was the first third-generation lunar orbiter. Luna 20 was a sample return mission that sent back 30g of moon regolith. Luna 21 was the second successful rover mission that landed Lunokhod 2. It had a top speed of 2 km/hr and used polonium-210 as a heat source. It operated for 4 months and travelled 37 km. The Lunokhod retroreflector is still used for lasers ranging from Earth.


Luna 22 was an orbiter mission similar to Luna 19. It tested lubricants on different frictional surfaces and studied different coatings with varying reflective properties. Luna 23 was a sample return mission that landed successfully but the sample return apparatus didn’t work, so no samples were obtained. Luna 24 was a successful sample return mission. It landed only a few hundred meters from Luna 23 and sent 170.1 g of samples.


Luna 1

Luna 1

Dark side of the moon photographed by Luna 3

Picture of dark side of Moon taken by Luna 3

Luna 16

Luna 16

Lunokhod 1

Lunokhod 1

Luna 25

Operator: Roscosmos

Target:  Moon

Landing date: August 10th 2023

Status:  Failed


The Luna 25 mission was launched in August 2023 on top of a Soyuz-2.1b rocket. The mission is targeting a lunar landing at the end of August 2023. The mission is the first moon mission of Russia since Luna 24 and the first moon mission flown since the fall of the soviet union. The mission has been in development for quite some time, at least since 2010 when Phobos Grunt was launched. Originally the mission was to include the ESA Pilot-D and the Swiss  LINA-XSAN payload, but these were removed in the wake of the Russian invasion of Ukraine. 


Luna 25 crashed during its landing attempt. From the last updates, it seems that a malfunctioning thruster caused the spacecraft to hit the moon prematurely. The satellite was first placed in a 100km polar orbit and it was intended to be placed in an elliptical orbit with a periapsis of only 18km above the surface of the moon. When the thruster fired too long this orbit started to intersect the moon [187].


Currently, it is unclear how this mission failure impacts the planned Luna 26, 27, and 28 missions.


Luna 25 on the moon

Render of Luna 25 on the moon

Zond Programme

Operator: Soviet space program

Target:  Moon

Landing date:  1964-1970

Status:  Retired


Zond program was two distinct series of spacecraft with the goal of exploration of nearby planets and robotic circumlunar loop flights and recovery.


Zond 1-3

Zond 1-3 used the 3MV planetary probe. Zond 1 and 2 were sent on Venus and Mars flyby respectively. However, both missions lost communication before they reached near the planets. Zond 3 was sent on a lunar flyby mission and was the second spacecraft to click a picture of the far side of the moon. It continued to a trajectory of Mars and eventually lost communication.  


Zond 4-8

Zond 4-8 were the soviet test flights during the moon race. They used the Soyuz L1 spacecraft. These spacecraft travelled in a free-return trajectory around the moon without going into lunar orbit. They were designed to potentially carry two astronauts.

Zond 4 was a test mission launched away from the moon and was supposed to make a skip re-entry. However, the separation mechanism of the re-entry module and service module failed which resulted in the trigger of the self-destruct mechanism at an altitude of 10-15 km/s.

Zond 5 improved on its predecessor and was the first spacecraft to travel around the moon and land safely on Early. Zond 5 had a payload of few animals such as tortoises, flies, worms, etc who returned alive. Additionally, it also carried a full-sized human mannequin with radiation detectors. Due to a failure of attitude sensors, the spacecraft performed a water landing in the Indian Ocean as opposed to a planned land landing.

Zond 6-8 were uncrewed test missions aimed at improving the reliability and circled the moon and landed on earth. Zond 6 aimed at land landing but suffered from cabin depressurisation. This depressurisation led to electronics malfunction and the spacecraft prematurely jettisoned the parachutes and fired the soft-landing thrusters 5.3 kms above the surface. While the capsule crashed, it was still recovered in a one piece.  Zond 6 was a precursor to crewed missions, but a range of technical problems prevented that from happening.

Zond 7 was the first in the series to perform a successful land landing and Zond 8 performed a successful sea landing. Unfortunately, these were not followed by crewed missions. Zond missions also carried scientific payloads and gathered data on cosmic rays, solar winds, radio emissions and micrometeoroids.


SLIM

Operator: JAXA

Target:  Moon

Landing date:  2023

Status:  Ongoing


Japan has recently launched a new lunar mission that aims to achieve a precise and soft landing on the Moon's surface. The mission, called SLIM (Smart Lander for Investigating Moon), is part of JAXA's (Japan Aerospace Exploration Agency) efforts to advance the exploration of the Moon and other planets using lighter and more efficient systems.

SLIM's landing system consists of four main components: a laser altimeter, a terrain camera, a navigation camera, and a guidance, navigation and control system. These components work together to enable SLIM to perform a pinpoint landing at a specific location within 100 meters, rather than the typical kilometer range.

The laser altimeter is a device that emits laser pulses and measures the time it takes for them to bounce back from the ground. This allows SLIM to determine its altitude and velocity relative to the lunar surface.

The terrain camera is a device that captures images of the landing site and compares them with a pre-loaded map of the area. This allows SLIM to identify its position and orientation on the map, and to avoid any obstacles or hazards.

The navigation camera is a device that tracks landmarks on the lunar surface, such as craters or mountains, and uses them as reference points. This allows SLIM to estimate its location and trajectory, and to correct any errors or deviations.

The guidance, navigation and control system is a software that processes the data from the sensors and computes the optimal commands for the thrusters and attitude control system. This allows SLIM to autonomously adjust its attitude and velocity during the landing phase, and to achieve a soft and accurate landing.

SLIM's scientific objectives are to conduct investigation of the Moon's origins by landing near the Marius Hills Hole, a possible skylight of a subsurface lava tube that could provide clues about the Moon's volcanic history and potential habitability. SLIM will also test technology fundamental to exploration in low-gravity environments, such as wireless power transmission, optical communication, and miniaturized instruments.

JAXA SLIM lander on the moon

Render of JAXA's SLIM lander on the moon

SLIM is expected to reach the Moon in late October 2023, after spending about 20 days in Earth orbit and about 30 days in lunar transfer orbit. It will then perform a powered descent maneuver that will last about 15 minutes and reduce its speed from 1.6 km/s to zero. If successful, SLIM will be the first Japanese spacecraft to land on the Moon, and the first in the world to achieve such a high level of landing accuracy. SLIM is an innovative mission that showcases Japan's technological prowess and scientific ambition in exploring the Moon. By achieving a pinpoint landing on the lunar surface, SLIM could open up new possibilities and opportunities for future lunar missions. We hope you will join us in following SLIM's journey and cheering for its success!


LUPEX

Operator: ISRO/JAXA

Target:  Moon

Landing date:  2026/28

Status:  Planned


The Lunar Polar Exploration Mission (LUPEX) is a joint venture between the Indian Space Research Organisation (ISRO) and the Japan Aerospace Exploration Agency (JAXA) to explore the south pole region of the Moon for water and other resources. The mission is expected to launch no earlier than 2026 using a Japanese H3 rocket and will consist of an Indian lander and a Japanese rover.

The main objective of LUPEX is to investigate the lunar polar region for the presence and potential usability of water, which could be a valuable resource for future human exploration and settlement of the Moon. The mission will also demonstrate new surface exploration technologies related to vehicular transport and lunar night survival, which are essential for sustainable exploration in the harsh environment of the polar regions.

The lander, developed by ISRO, will carry a payload capacity of 350 kg (770 lb) and will use a feature matching algorithm and navigational equipment derived from JAXA's Smart Lander for Investigating Moon (SLIM) mission for precision landing. The rover, developed by JAXA, will carry multiple instruments by both agencies, including a drill to collect sub-surface samples from 1.5 m (4 ft 11 in) depth.

LUPEX is poised to be a trailblazer in providing concrete answers to the scientific questions about the lunar water resources and their origin, distribution, and evolution. The mission will also pave the way for future collaboration between ISRO and JAXA in lunar exploration and beyond.


Configuration of the LUPEX lander

Ranger Programme

Operator: NASA

Target:  Moon

Landing date:  1961-1965

Status:  Retired


The Ranger program often referred as the “Shoot and Hope” program in its early years were a series of spacecraft launched to advance American space technology and map the surface of the moon. The program was divided into three key blocks. The spacecrafts within the three blocks were nearly identical to each other. The first 6 mission of the Ranger program failed and missions 7,8 and 9 succeeded. The Ranger spacecrafts were launched on the Atlas rockets and used the Agena second stage to propel them towards the moon. All the missions in the Ranger program were designed to be impactors due to launcher limitations.


Ranger Block 1

Ranger 1 & 2 were meant to test the operations and reliability of the different subsystems. They both failed in low earth orbit after stabilisation issues.


Ranger Block 2

The second block of Ranger spacecraft had a lot more scientific instruments than the first block such as Gamma Ray Spectrometer, TV Camera, Radio Altimeter, etc. It also had a Lunar Impacting Capsule which was meant to survive a 100 mile/hr impact and make measurements for 30 days. The capsule has a seismometer to measure moonquakes. The instrument was housed around two layers of liquids, liquid Freon and water respectively. Additionally, the liquids were housed inside a Balsa wood shell. The iconic stripe paint pattern was chosen to minimise thermal variance in the instrument environment.

Ranger 3 missed the moon by 38,800 km and is still orbiting the Sun. Ranger 4 had a perfect launch, but spacecraft communications got disabled. The capsule impacted the lunar far side. Ranger 5 missed the moon by 725 km

Ranger 5

Ranger 5

Ranger Block 3

After the failure of the first two blocks, there was intense pressure to get things working. Therefore, redundancy was added in most key systems such as Power, Communications and TV Cameras. There were 6 cameras with different lenses on board block 3 spacecraft. The cameras fired one after the other to prevent excessive heat and could capture one image every 10 seconds. The communication equipment was designed to send pictures up to 0.2 second before impact.

Ranger 6 impacted the moon, but cameras failed. Ranger 7 was the first successful mission of the program and sent close-up pictures of the lunar surface in July 1, 1964. Ranger 7 had a successful impact and sent over 4000 pictures. Ranger 8 also had a successful impact and sent over 7000 pictures. Ranger 8 had a successful impact and sent over 5800 pictures


Apollo Lunar Excursion Module

Operator: NASA

Target:  Moon

Landing date:  1969 (Apollo 11)

Status:  Retired


The Apollo Lunar Excursion Module, LEM, was the moon lander of the Apollo project. The LEM was stored in the Saturn V and extracted by the command module after launch. For transit, the LEM would be attached to the forward docking port of Apollo. When the stack was in lunar orbit, two crew members would transfer to the LEM and prepare for landing. The LEM consisted of two parts, the descent and ascent stage. The descent stage was on the bottom of the stack and was powered by a hyperbolic engine with a throttle range of 65 to 92.5%. This allowed for sufficient control for a safe landing. The descent stage also housed the landing legs. These legs would dampen the final landing and housed probes to help the astronauts determine their distance to the lunar surface. The "upper stage" or ascent module also used a hyperbolic engine. It would allow the two astronauts to return to lunar orbit, where they would dock with the orbiting Apollo command module. 


The video on the right shows the lift-off of Apollo 17 filmed by the lunar rover. The descent stage is left on the moon and the ascent stage flies off. Note how the exhaust of the N2O2-Aerozine 50 combustion is clear and no flame can be seen. A similar phenomenon was observed in the 2021 Perseverance lander. 

LK lander

Operator: Soviet space program

Target:  Moon

Landing date:  Never flew to the moon

Status:  Cancelled


The LK lander was the Russian alternative to the Apollo LM. The Lk would have launched onboard the N1 rocket below the Soyuz module much like Apollo and LEM were launched. The LK would be extracted after launch and when the combination was around the moon a single cosmonate would space walk over to the Lk. The LK was quite a bit smaller, weiging between 5560 and 6525 kg compared to 15200 and 16400 for the LEM. The Lk only had one hypergolic engine that would be usedo n both ascent and descent flight. The landing legs would stay behind on the moon. Later LK landers would be upgraded to two crew members

LK lander

LK lander

Chang'e program

Operator: SNSA

Target:  Moon

Landing date:  01-12-2020

Status:  Completed


The Chinese Lunar Exploration Program started with two successful orbital missions launched in 2007 and 2010. The second two missions, Chang'e 3 and 4 showed the Chinese ability to soft-land on the moon. Both landers were about 1200 including a 400 kg rover. Chang'e 3 worked for 959 days, where Chang'e 4 is active today. Before the sample return mission Chang'e 5, there was an intermediate demonstrator called Chang'e 5-T1. This mission was launched in October 2014 to test the re-entry leg of the sample return. The mission became the first successful skipping entry. Chang'e 5 was launched in November 2020, landed in December 2020 and returned to earth on the 16th of that month. The mission marked the first Lunar sample return since Luna 24. The earth entry probe resembled a scaled-down Shenzhou capsule, which in term resembles the Soyuz capsule. 


The follow-up mission, Chang'e 6, is scheduled for 2024 and will repeat the Chang'e 5 mission on the Lunar south pole.


Beresheet 

Operator: Israel Aerospace Industries

Target:  Moon

Landing date:  22-02-2019

Status:  Completed, failed


In 2019 the Israeli company Isreal Aerospace Industries became the first commercial company to land a mission on the moon. The mission was launched onboard a Space X falcon 9 together with the PSN-6 satellite. The lander then used its own engines to fly to the moon where it entered a circular lunar orbit. Just before landing a gyroscope failed which could not be solved due to a sudden loss of communication. When communication was restored the capsule had already impacted the moon. At an altitude of 150, the 150 kg (dry mass) lander was still falling at 140 m/s. A second mission is planned for 2024 including a Moon and Mars lander. 


Moon impact Probe

Operator: ISRO

Target:  Moon

Landing date:  November 14th 2008

Status:  Completed


On ISRO's first moon mission, Chandrayaan-1, was a small piggyback lander. This lander, the Moon Impact Probe, was designed to impact the moon sometime after being released from the main vehicle. After separation from the main mission, the probe spun up for stability and fired its retro rocket motor. This caused the orbit of the lander to decrease and thus intersect the surface of the moon. After a 25-minute descent phase the probe "hard landed" with a velocity of 1.69 km/s.

Even though the mission was short it showed ISRO's capabilities of reaching the surface of the moon. Marking India to be the fourth nation to do so. Furthermore, the mission discovered the presence of water just before it hit the ground. This discovery was not made public until the Moon Mineralogy Mapper, a NASA experiment onboard Chandrayaan-1, confirmed this discovery. 


ISRO Moon Impact Probe before launch

Moon Impact Probe before launch

Chandrayaan-2, Vikram lander

Operator: ISRO

Target:  Moon

Landing date:  22-07-2019

Status:  Completed, failed


In 2019 India embarked on the ambitious mission to become the fourth nation to soft-land a lander on the moon. This lander was launched in July 2019 onboard a GSLV Mark-III as part of the Chandrayaan-2 mission. This mission contained an orbital module, lander and rover. After the Chandrayaan-2 mission entered lunar orbit, the lander detached and moved to a lower orbit. Unfortunately, the 1471 kg rover crash crashed due to a computer glitch. During the landing, the velocity was supposed to be changed from 1683 to 146 m/s. However, the capsule flew faster than expected, and thus the landing was hard. Even though the landing was unsuccessful, it impacted close to the predicted landing site. The lander and rover were destroyed upon impact. 


Chandrayaan-3

Operator: ISRO

Target:  Moon

Landing date:  2023

Status:  Completed


After the crash of Chandrayaan-2, ISRO officials announced a new moon lander. This lander was to learn from the mistakes of Chandrayaan-2. The main updates included a redesign of the landing engines and the landing software. The software now allowed for attitude corrections in all phases of flight and the control of the attitude was provided by four downwards-facing rockets. 

The lander landed successfully on November 23 2023, after which it deployed a moon rover. This landing makes India the fourth nation to soft land on the moon and the first lander on the lunar south pole. 

Chandrayaan 3 on the moon, photographed by the rover

Chandrayaan 3 on the moon, photographed by the rover

OMOTENASHI

Operator: JAXA

Target:  Moon

Landing date: November 2022

Status:  Completed, failed


OMOTENASHI is one of the CubeSats flying onboard the Artemis 1 mission to the moon. The objective of OMOTENASHI is to demonstrate low-cost landing techniques for the moon. After separation, the satellite will spin up and ignite a small solid rocket motor. The burn will last for about 15 to 20 seconds.  It will then separate the lander from the motor and inflate a 50cm airbag. This airbag ensures a safe landing. The final free-fall is about 100 meters and the final impact will be between 20 and 30 m/s.


After the successful launch in November 2022, the satellite was separated from the Orion spacecraft. Unfortunately, the team on the ground was not able to establish communications with the lander and were thus not able to start the landing sequence. The satellite remains in Lunar orbit. 

Render of the OMOTENASHI lander

Render of the OMOTENASHI lander

Hakuto-R

Operator: ISpace

Target:  Moon

Landing date: April 2023 (First flight)

Status:  Operational - in test phase


The Hakuto-R lander has a long history starting in the days of the Google Lunar X Prize to kickstart the moon landers in 2007. Even though the Hakuto lander did not reach a flight-ready state during the competition it managed to fly in November 2022. This launcher included the Rashid rover, the first moon rover of the UAE.


After the launch in 2022, the lander reached the moon. On the 25th of April, the landing attempt was started but ended

with the lander not responding. Currently, the lander is considered lost.


Render of the Hakuto-R lander

Render of the Hakuto-R lander

Overview of Lunar Landers

The table below shows the first moon landing attempts starting in 1958. As the moon has no atmosphere all of them used some form of propulsive deceleration if needed. From the table, it can be seen that the first landers used a much simpler impact strategy. This means the kinetic energy upon touchdown is higher, but the capsule is designed to handle this. This overview only contains missions that attempted a lunar landing and not failed missions that never started the landing operation.


Mission

Nationality

Year

Mission type

Status

Luna 1

Soviet Union

1959

Impactor

Failure - Did not impact, made the first fly by of the moon

Luna 2

Soviet Union

1959

Impactor

Succesfull

Ranger 3

USA

1962

Impactor

Failure - Guidance problem

Ranger 4

USA

1962

Impactor

Failure - Did not deploy solar panels

Ranger 5

USA

1962

Impactor

Failure - Solar panels shut down by accident

Ranger 6

USA

1964

Impactor

Succesfull impact, did not return science data

Ranger 7

USA

1964

Impactor

Succesfull

Ranger 8

USA

1964

Impactor

Succesfull

Ranger 9

USA

1965

Impactor

Succesfull

Luna 5

Soviet Union

1965

Lander

Failure - Hard landing

Luna 6

Soviet Union

1965

Lander

Failure - Guidance error, became a fly by

Luna 7

Soviet Union

1965

Lander

Failure - Hard landing

Luna 8

Soviet Union

1965

Lander

Failure - Landing system failure

Luna 9

Soviet Union

1966

Lander

Succesfull

Surveyor 1

USA

1966

Lander

Succesfull

Surveyor 2

USA

1966

Lander

Failure - Lost in transit

Luna 13

Soviet Union

1966

Lander

Succesfull

Surveyor 3

USA

1967

Lander

Succesfull

Surveyor 4

USA

1967

Lander

Failure - Loss of contact

Surveyor 5

USA

1967

Lander

Succesfull

Surveyor 6

USA

1967

Lander

Succesfull

Surveyor 7

USA

1968

Lander

Succesfull

Zond 4

Soviet Union

1968

Lunar loop flight

Partial success

Zond 5

Soviet Union

1968

Lunar loop flight 

Success - Rough landing

Zond 6

Soviet Union

1968

Lunar loop flight

Partial success

Zond 7

Soviet Union

1969

Lunar loop flight

Success

Luna 15

Soviet Union

1969

Lander

Failure - Landing

Apollo 11

USA

1969

Lander - Crewed

Success - First human landing on the moon

Apollo 12

USA

1969

Lander - Crewed

Success

Zond 8

Soviet Union

1970

Lunar Loop flight

Success

Luna 16

Soviet Union

1970

Sample return

Success

Luna 17

Soviet Union

1970

Lander - Rover

Success - First rover

Luna 18

Soviet Union

1970

Sample return

Failure - Landing

Apollo 14

USA

1971

Lander - Crewed 

Success

Apollo 15

USA

1971

Lander - Crewed

Success

Apollo 16

USA

1972

Lander - Crewed

Success

Luna 20

Soviet Union

1972

Sample return

Success

Luna 21

Soviet Union

1972

Lander - Rover

Success

Apollo 17

USA

1972

Lander - Crewed

Success

Luna 23

Soviet Union

1974

Sample return

Failure

Luna 24

Soviet Union

1976

Sample return

Success

Moon Impact Probe

ISRO

2008

Impactor

Success

Chang'e 3 + Yuto

China

2013

Lander - Rover

Success

Chang'e 4 + Yutu-2

China

2019

Lander - Rover

Success

Beresheet

Israel

2019

Lander

Failure - Landing

Vikram lander

India

2019

Lander

Failure - Landing

Chang'e 5

China

2020

Sample return

Success

OMOTENASHI

Japan

2022

Lander

Failed after separation with SLS

Hakuto-R M1

ISpace

2022

Lander

Failure - Landing

Luna 25

Roscosmos

2023

Lander

Failure

Chandrayaan 3

ISRO

2023

Lander

Success

SLIM

JAXA

2023

Lander

Success - Partial

Peregrine

USA - Astrobotic Technology

2024

Lander

Failed - in Transit

Nova-C Odysseus

USA - Intitive Machines

2024

Lander

Success - Partial

v0.2 - 25-04-2020