Lunar lander
The relatively high gravity (higher than all known asteroids, but lower than all Solar System planets) and lack of lunar atmosphere negates the use of aerobraking, so a lander must use propulsion to decelerate and achieve a soft landing.
The Luna program was a series of robotic impactors, flybys, orbiters, and landers flown by the Soviet Union between 1958 and 1976.
India's Chandrayaan Programme conducted an unsuccessful robotic lunar soft-landing attempt on 6 September 2019 as part of its Chandrayaan-2 spacecraft with the lander crashing on the Moon's surface.
[2] On 23 August 2023, the program's follow-up Chandrayaan-3 lander achieved India's first robotic soft-landing and later conducted a brief hop on 3 September 2023 to test technologies required for Indian lunar sample return mission called Chandrayaan-4.
[3] Japan's ispace (not to be confused with China's i-Space) attempted a lunar soft-landing by its Hakuto-R Mission 1 robotic lander on 25 April 2023.
[6][7][8] In January 2024, the first mission of the NASA-funded CLPS program, Peregrine Mission One, suffered a fuel leak several hours after launch, resulting in losing the ability to maintain attitude control and charge its battery, thereby preventing it from reaching lunar orbit and precluding a landing attempt.
The second CLPS probe Odysseus landed successfully on 22 February 2024[10] on the Moon, marking the United States' first unmanned lunar soft-landing in over 50 years.
It was later ejected on 28 February but was partially failure as it returned all types of data, except post IM-1 landing images that were the main aim of its mission.
[17] The Chang'e 6 lander successfully landed in the South pole-Aitken basin on the lunar far side at 22:23 UTC on 1 June 2024.
Firefly Aerospace's lunar lander, carrying NASA-sponsored experiments and commercial payloads as a part of Commercial Lunar Payload Services program to Mare Crisium, was launched on 15 January 2025 on a Falcon 9 launch vehicle with Hakuto-R Mission 2.
[25] The following table details the success rates of past and on-going lunar soft-landing attempts by robotic and crewed lunar-landing programs.
Practically, this means that the only method of descent and landing that can provide sufficient thrust with current technology is based on chemical rockets.
[31] As of 2019,[update] space probes have landed on all three bodies other than Earth that have solid surfaces and atmospheres thick enough to make aerobraking possible: Mars, Venus, and Saturn's moon Titan.
These probes were able to leverage the atmospheres of the bodies on which they landed to slow their descent using parachutes, reducing the amount of fuel they were required to carry.
[33] The lack of an atmosphere, however, removes the need for a Moon lander to have a heat shield and also allows aerodynamics to be disregarded when designing the craft.
This is in contrast to a small asteroid, in which "landing" is more often called "docking" and is a matter of rendezvous and matching velocity more than slowing a rapid descent.
The length of the lunar night makes it difficult to use solar electric power to heat the instruments, and nuclear heaters are often used.
The first soft lunar landing, performed by the Soviet Luna 9 probe, was achieved by first slowing the spacecraft to a suitable speed and altitude, then ejecting a payload containing the scientific experiments.
[42] Perhaps the most famous lunar landers, those of the Apollo Program, were robust enough to handle the drop once their contact probes detected that landing was imminent.
