Tokyo - The Japanese Aerospace Exploration Agency (JAXA) held a press conference last Thursday confirming the successful lunar landing of their small lander and rover mission SLIM (Smart Lander for Investigating Moon) on January 19th. However, communication issues cut the first contact short as the solar panels were incorrectly oriented to charge onboard batteries.
SLIM touched down only about 12 meters away from its targeted landing site thanks to an advanced real-time guidance system tested during the descent. But the lander tilted sideways upon impact and was unable to sufficiently charge batteries using sunlight. After briefly establishing communication and deploying two tiny rovers called LEV-1 and LEV-2, SLIM entered hibernation mode.
The rover LEV-2 managed to locate SLIM’s landing site and transmit an image back to Earth showing the lander’s precarious tilted position. SLIM’s landing legs and engines are visible atop the lunar surface while the deployable solar arrays remain fixed horizontally on the lander’s side. This orientation meant the arrays could not track the Sun to recharge onboard batteries.
JAXA stated the mission meets minimum success criteria by proving precise powered descent and landing technologies. The LEV rovers also exceeded expectations functioning for nearly two hours and traveling farther than required. LEV-2, weighing only 180 grams, earned the title of smallest operational lunar rover.
While unable to revive thus far, engineers remain hopeful SLIM may reactivate before the 14-Earth-day lunar night falls on February 1st when temperatures drop dramatically. JAXA continues to analyze telemetry data from the lander’s descent, which showed one of its redundant engines unexpectedly cut out around 50 meters altitude resulting in off-nominal sideways velocity.
The data obtained from SLIM’s partial mission will still provide key insights towards Japan’s future lunar ambitions. JAXA stated lessons learned will aid upcoming lunar landing attempts as well as a planned 2024 sample return mission from the Moon’s polar regions.
