During the night from Friday to Saturday, the Japanese space module Slim (Smart Lander for Investigating Moon) managed to land on the Moon, according to the Japanese space agency Jaxa, subject to verification of telemetry data. Slim, who had been orbiting the rocky star since the end of December, had begun his descent about twenty minutes earlier at a speed of around 1,700 meters per second.
This small unmanned spacecraft (2.4 m long, 1.7 m wide and 2.7 m high) was not only supposed to land on the moon, but also to land within a radius of 100 meters from its target. Such a radius is considered a high degree of precision. Hence his nickname “Moon Sniper”. It is common for lunar vehicles to land several kilometers from their target, which can complicate their exploration missions. And landing on the Moon is more difficult than landing on asteroids because gravity on the Moon is stronger than on small celestial bodies.
A “huge challenge” “exceptionally technologically difficult”
Landing precisely on the Moon is “a huge challenge” for SLIM, Emily Brunsden, director of the Astrocampus at the University of York, told AFP. The precision of the “Sniper” constitutes “an enormous technological progress which will make it possible to design missions aimed at answering much more specific research questions”. But achieving this feat is “exceptionally technologically difficult”. “There is usually only one chance, so even the slightest mistake can result in mission failure,” she warns.
SLIM was to land in a small crater less than 300 meters in diameter called Shioli, from where the machine should be able to carry out ground analyzes of rocks believed to come from the lunar mantle, the internal structure of the Earth’s natural satellite, which is still very poorly known. This mission also aims to advance research on water resources on the Moon, a key issue, as the United States and China ultimately intend to install inhabited bases there.
Japan’s first two moon landing attempts went wrong. In 2022, a Jaxa mini-probe, Omotenashi (“hospitality” in Japanese), which was on board the American Artemis 1 mission, experienced a fatal battery failure shortly after its ejection into space. And in April 2023, a lander from the young private Japanese company ispace crashed on the surface of the Moon, having failed the smooth descent stage.
For its part, NASA has postponed the next two missions of its major return to the Moon program called Artemis until September 2025 and September 2026.