SLIM

Key facts

Mission & specifications

Mission

SLIM — the Smart Lander for Investigating Moon, nicknamed the 'Moon Sniper' — was Japan's demonstration that a spacecraft could land not just on the Moon, but on a chosen spot the size of a back garden. Most landers aim for a wide, safe ellipse; SLIM aimed to touch down within a hundred metres of its target, the kind of precision future missions will need to reach specific science sites or scarce polar resources. On 20 January 2024 it succeeded — making Japan only the fifth nation to land softly on the Moon — and it hit its mark, coming down within about 55 metres of the target. But the touchdown was not flawless. In the final descent one of its two main engines failed, and SLIM came to rest tipped onto its nose, its solar panels pointed the wrong way. For a time it ran on battery alone, returning images and science before powering down. Then came the surprises. As the lunar day shifted the angle of the sunlight, SLIM's panels caught the Sun and the little lander woke up — and it did so again and again, surviving the brutal two-week lunar nights, where the cold falls below minus 170 °C, that it was never built to endure. Each unexpected revival delighted its team. SLIM proved both a new standard of landing accuracy and the stubborn resilience of a well-made machine.

1. 2023Launch of the Moon SniperLaunch

   JAXA's precision lander lifts off, sharing its rocket with the XRISM telescope.

2. 2024Pinpoint landing at ShioliLanding

   Touches down within ~55 m of its target — but tips onto its nose after an engine fails.

3. 2024Awake on solar powerMilestone

   As the Sun shifts, the mis-pointed panels catch light and SLIM revives to do science.

4. 2024Last contactMission end

   After repeatedly surviving the lunar night it was never built for, SLIM finally falls silent.

Images

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