Smart Lander for Investigating Moon. Japan's precision lunar landing demonstrator. Made Japan the fifth nation to land on the Moon.
SLIM (Smart Lander for Investigating Moon) demonstrated unprecedented precision landing on the Moon when it touched down on January 20, 2024, just 55 meters from its target point near Shioli crater — far exceeding the 100-meter accuracy goal. The mission made Japan the fifth nation to achieve a soft landing on the Moon, after the Soviet Union, the United States, China, and India.
The mission used a novel two-phase landing approach: first a vertical descent to about 50 meters altitude, then a horizontal scan using image-based navigation to identify the optimal landing spot by matching terrain features to onboard maps. However, one of SLIM's two main engines lost thrust during final descent, causing the lander to touch down nose-first and flip upside down.
Despite the inverted orientation, SLIM's solar panels eventually generated power when lighting conditions changed, and the lander communicated with Earth multiple times over subsequent lunar days — surviving the extreme temperature swings of lunar night (as cold as -130°C) that most missions cannot endure. The mission formally ended on August 23, 2024 after the lander failed to respond following its third lunar night.
Demonstrate precision landing within 100 meters of a predetermined target, achieving "pinpoint" accuracy far beyond typical lunar landing capabilities of ~1-10 km.
Validate crater-recognition autonomous navigation by matching real-time camera images to onboard terrain maps during descent, enabling precision targeting without ground-based guidance.
Deploy two small exploration robots: LEV-1 (a hopping rover from JAXA) and LEV-2 (a baseball-sized spherical rover co-developed with Tomy, capable of transforming shape to roll across the surface).
Investigate olivine-rich rocks exposed at Shioli crater to study the composition of the lunar mantle, which is believed to be exposed in this region.
Demonstrate that a small, lightweight, and cost-effective spacecraft can achieve precision lunar landing, reducing the cost barrier for future science missions.
SLIM achieved its primary objective of pinpoint landing with remarkable precision — just 55 meters from target, far exceeding the 100-meter goal. However, one of the two main engines lost thrust during the final descent phase, causing the lander to touch down nose-first and flip upside down. The inverted orientation initially prevented the solar panels from generating power, but both LEV-1 and LEV-2 mini rovers were ejected just before landing and captured images of the inverted SLIM on the surface.
When lighting conditions shifted, SLIM's panels began generating power, and the lander communicated with Earth across three subsequent lunar days before finally going silent on August 23, 2024. The precision navigation technology was the mission's true triumph, proving that pinpoint landing is achievable.
Japan's SLIM lander touched down approximately 55 meters from its target at Shioli crater, demonstrating unprecedented pinpoint landing accuracy. Japan became the fifth nation to achieve a lunar soft landing. The lander later survived multiple lunar nights.
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