Landing on the Moon requires slowing a spacecraft from orbital speed (roughly 3,700 mph) to a near standstill, navigating to a safe patch of ground, and touching down gently enough to keep everything intact. There’s no atmosphere to deploy parachutes, no GPS to guide you in, and a radio signal takes about 1.3 seconds each way between Earth and the Moon. That delay means the final moments of every lunar landing depend on the spacecraft itself, whether guided by a human pilot or an onboard computer making split-second decisions.
Getting Into Lunar Orbit First
No spacecraft lands on the Moon directly from Earth. The vehicle first enters lunar orbit, a looping path around the Moon that serves as a staging area. Apollo missions used a near-circular orbit about 60 miles above the surface. NASA’s upcoming Artemis missions use a more energy-efficient path called a near-rectilinear halo orbit, which swings as close as 1,000 miles and as far as 43,000 miles from the Moon.
From orbit, the lander separates from any mothership or crew vehicle and fires its engines in what’s called a descent orbit initiation burn. This nudge lowers one side of the orbit so the spacecraft’s path intersects with the surface at the chosen landing site. After the burn, the lander coasts for a short period before beginning powered descent, the final engine-firing sequence that brings it down to the ground.
Choosing Where to Touch Down
A lunar landing site has to satisfy several constraints at once. The ground needs to be flat, with gentle slopes and minimal boulders. For missions near the Moon’s south pole, where NASA’s Artemis program is focused, sunlight is the critical factor. Because the Sun sits low on the horizon at high latitudes, even small hills cast long shadows that can leave a lander in darkness for days. Artemis planners identified 130 candidate sites by searching for flat regions that receive continuous sunlight for at least one week, long enough to power the first surface missions, which are planned for roughly 6.5 days.
Scientists also want landing sites near permanently shadowed craters, where water ice may be trapped. The ideal spot puts astronauts within a 2-kilometer walk of one of these dark craters while still sitting in reliable sunlight. That combination of safety, power, and science value narrows the options considerably.
The Powered Descent Sequence
Powered descent is the phase that makes or breaks a landing. It typically unfolds in three stages. First, the braking burn: the engine fires at high thrust to shed most of the spacecraft’s orbital velocity. This phase covers the majority of the altitude drop and lasts several minutes. Second, the approach phase: the spacecraft pitches forward so its cameras and sensors can scan the landing zone ahead. Third, terminal descent: the vehicle hovers briefly, translates sideways if needed to avoid hazards, and lowers itself vertically to the surface.
Apollo 11 illustrates how tense this sequence can be. During the final minutes, Neil Armstrong saw that the automatic guidance was steering the lunar module toward a boulder field. He took manual control, flying the spacecraft horizontally until he found a clear spot. Post-flight analysis showed he touched down with about 770 pounds of fuel remaining, enough for roughly 45 seconds of flight including 20 seconds reserved for an abort. The other five Apollo commanders who landed all had a more comfortable margin of 1,100 to 1,200 pounds of usable fuel left.
How a Lander Knows Where It Is
Without GPS satellites orbiting the Moon, a lander has to figure out its own position by looking at the terrain below. This technique, called terrain relative navigation, compares what the spacecraft’s cameras see with maps stored in its onboard computer. Modern landers combine optical cameras with LiDAR sensors that bounce laser pulses off the ground to build a 3D picture of the surface in real time. Stereo camera pairs provide depth information that complements the laser data, and together these sensors can pinpoint the spacecraft’s location to within a few meters.
This technology has matured significantly. NASA’s Mars 2020 mission used a camera-based vision system to guide the Perseverance rover to a precise landing spot, and similar systems are now standard on lunar landers. Machine learning algorithms can process the incoming images and depth data to estimate position faster than traditional methods, which matters when the ground is rushing up and every second counts.
Why the Last 100 Meters Are the Hardest
The final stretch of a lunar landing introduces a unique hazard: the engine plume blasting into loose soil. The Moon’s surface is covered in regolith, a layer of fine, jagged dust and small rocks. When rocket exhaust hits this material at close range, it kicks up a spray of particles at high speed. Some of that debris flies outward and some of it ricochets back into the lander, sandblasting sensors, coating solar panels, and potentially damaging nearby equipment. NASA is actively testing plume-surface interactions at its Langley Research Center, measuring crater formation, particle speed, and ejecta angles to predict how future landers will disturb the ground.
Visibility drops dramatically during this phase too. Apollo astronauts reported a near-total whiteout from dust in the final seconds before touchdown. For uncrewed landers relying on cameras, that dust cloud can blind the very sensors guiding the descent. This is one reason the onboard computer needs to have its landing solution locked in well before the final moments.
What Happens if Something Goes Wrong
Every lunar landing includes an abort option. If the lander detects a problem during descent, it can fire its engines to climb back to a safe orbit. The timing matters: the earlier in the descent an abort is called, the less fuel it takes to recover. As the lander gets closer to the surface and loses altitude, the required thrust angle and burn duration change rapidly. Apollo-era abort plans gave the pilot a set of charts correlating the elapsed time since descent began with the exact engine angle and burn length needed to return to orbit safely, with the requirement that the spacecraft clear at least 20,000 feet above the surface.
Critically, the descent engine and the ascent engine are separate systems with separate fuel supplies. Even if a lander runs completely dry during descent, the ascent stage can still fire independently to get the crew back to orbit. Apollo 11’s ascent module was never at risk of being stranded, regardless of how tight the descent fuel margins got.
How Private Companies Are Doing It Now
Landing on the Moon is no longer limited to government space agencies, but the track record shows just how difficult it remains. Before 2024, three private companies from Israel, Japan, and the United States (Astrobotic) all failed to achieve soft landings. Astrobotic’s Peregrine lander suffered a propulsion system leak shortly after launch in January 2024 and never reached the surface.
The breakthrough came in February 2024 when Intuitive Machines’ Odysseus lander touched down near the Moon’s south pole, becoming the first commercially built and operated spacecraft to achieve a soft lunar landing. It was also the first American landing in over 50 years. The success wasn’t flawless: the signal after touchdown was faint, and controllers initially couldn’t confirm the lander’s orientation. It turned out Odysseus was upright and transmitting data, but the uncertainty in those first minutes underscored how little margin these missions have.
The Artemis Approach for Crewed Landings
NASA’s plan for returning astronauts to the Moon uses SpaceX’s Starship as the human landing system. The sequence is more complex than Apollo’s. A Starship configured as a propellant depot launches to low Earth orbit first. Tanker Starships then launch repeatedly to fill it with fuel. The crew-rated Starship launches separately, docks with the depot to top off its tanks, and then flies to lunar orbit.
Once in the Moon’s vicinity, astronauts transfer from NASA’s Orion capsule into the Starship lander. When the crew is ready, Starship undocks and performs a departure burn to begin its roughly half-day transit from the halo orbit down to a circular low lunar orbit about 60 miles up. From there, the crew suits up, the computer updates its navigation fix, and Starship performs its final descent burn to arrive within 100 meters of the target landing site. The vehicle uses its Raptor engines for both the descent and a powered vertical landing, the same basic technique SpaceX has practiced with its Falcon boosters on Earth, adapted for a world with one-sixth the gravity and no atmosphere.