JAXA SLIM Lunar Lander — Specs & Review
Specifications
| Brand | JAXA |
|---|---|
| Model | SLIM Lunar Lander |
| Year | 2024 |
| Category | Space |
| Autonomy | semi-autonomous |
| Environment | outdoor |
| Connectivity | JAXA Ground Stations, DSSC Deep Space Network |
| Country of origin | JP |
Key features
- World's most precise Moon landing at time of touchdown (55m accuracy)
- Japan's first Moon landing and 5th country to soft-land on Moon
- Image-matching autonomous boulder detection and avoidance
- Deployed LEV-1 hopping rover and LEV-2 Sora-Q sphere rover
- Validates pinpoint landing for future resource and science missions
- Camera-based terrain navigation during final descent
- January 20, 2024 successful landing
What is it?
SLIM (Smart Lander for Investigating Moon) is JAXA's technology demonstration lunar lander, designed to prove pinpoint landing capability — achieving targeted touchdown within 100 metres of a designated site rather than the typical several-kilometre landing ellipses of earlier missions.
Mission facts
- Landing date: January 20, 2024
- Landing site: Near Shioli Crater, Mare Nectaris, Moon
- Landing precision: 55 metres from target (world's best at time of landing)
- Navigation: Image-matching autonomous hazard detection
- Power: Solar panels (landed sideways — panels not initially sun-facing)
- Deployment: Released two mini-rovers (LEV-1, LEV-2)
- Japan: 5th country to achieve soft Moon landing
Pinpoint landing significance
Earlier lunar missions had landing ellipses of several kilometres — engineers had to pick large flat plains to guarantee a safe landing anywhere in that ellipse. SLIM's 55-metre accuracy means future missions can target specific scientifically valuable sites (crater rims, lava tube openings, ice deposits in permanently shadowed regions) with confidence.
Technical innovation
SLIM's guidance system uses a camera and pre-loaded terrain map to match visual features during descent, autonomously identifying and avoiding boulders in real time — significantly more precise than inertial guidance alone.
Power anomaly
SLIM landed with its solar panels facing the wrong direction (the lander tipped slightly on landing). After initial battery-powered operations, JAXA powered down the lander to wait for changing sunlight angles. In late January and February 2024, the panels received sunlight and SLIM resumed operations for science observations.
Mini-rovers
SLIM deployed LEV-1 (hopping robot) and LEV-2 (sphere robot "Sora-Q", developed with Tomy) that drove away and photographed the lander on the surface, providing independent visual confirmation of the landing configuration.
FAQ
How precise was SLIM's Moon landing?
SLIM landed within 55 metres of its target site near Shioli Crater — the most precise Moon landing achieved at that date, compared to landing ellipses of several kilometres for earlier lunar missions.
Why is pinpoint landing important?
Pinpoint landing allows missions to target scientifically valuable or resource-rich locations (crater rims, lava tube openings, ice deposits) with precision. Conventional landing ellipses of kilometres require landing in large flat plains wherever they happen to fall.
Did SLIM have a power problem on landing?
Yes. SLIM landed with its solar panels facing away from the Sun due to a slight tip at touchdown. JAXA powered down after initial operations and waited for changing sunlight angles in late January 2024, when the panels received light and operations resumed.
What mini-rovers did SLIM deploy?
SLIM deployed two mini-rovers: LEV-1 (a hopping robot for communication and surface exploration) and LEV-2 (Sora-Q, a 250g sphere robot co-developed with Tomy that drove away and photographed SLIM on the surface).
Which countries have soft-landed on the Moon?
Five countries have achieved soft lunar landings: the Soviet Union (1966), the United States (1966), China (2013), India (2023 Chandrayaan-3), and Japan (2024 SLIM).