Smart Lander for Investigating Moon

The Smart Lander for Investigating Moon (SLIM), nicknamed the "Moon Sniper", was a lunar lander mission operated by the Japan Aerospace Exploration Agency (JAXA). Manufactured by Mitsubishi Electric, it was launched on September 6, 2023, aboard an H-IIA rocket from the Tanegashima Space Center, together with the X-Ray Imaging and Spectroscopy Mission (XRISM) space telescope. SLIM entered lunar orbit on December 25, 2023, and successfully soft-landed on the Moon on January 19, 2024, making Japan the fifth country to accomplish a soft landing on the Moon, after the Soviet Union, the United States, China, and India.

SLIM's primary objective was to demonstrate precision lunar landing technology. Using facial recognition-derived image processing to identify lunar craters and data from the SELENE orbiter for navigation, it aimed to land within 100 m (330 ft) of its designated target near Shioli crater in the Sea of Nectar—a level of accuracy far exceeding that of earlier missions. Although the landing was successful, the spacecraft came to rest on its side, leaving its solar panels oriented away from the Sun and limiting initial power generation. After a brief period of battery-powered operation, SLIM was powered down on January 20, 2024 (JST), only to be revived nine days later when the sunlight shifted to its panels.

SLIM carried two small lunar rovers: LEV-1, a hopping rover with direct-to-Earth communication capability, and LEV-2 (Sora-Q), a baseball-sized rover jointly developed with Tomy, Sony, and Doshisha University. Both were successfully deployed during descent. Although SLIM was not designed to survive the extreme cold of lunar night, it did so repeatedly, waking up for a total of four lunar days before going silent in late May 2024. JAXA officially declared the mission concluded on August 23, 2024. In doing so, SLIM set a world record for longevity among lunar surface spacecraft lacking a radioisotope thermoelectric generator (RTG).