'Ohayo' from the Moon: Japan's SLIM Lander Survives Lunar Night

The Japan Aerospace Exploration Agency (JAXA) reported on Monday (Feb. 26) that they had made contact with its Smart Lander for Investigating Moon (SLIM) lander on Feb. 25, despite fears that the spacecraft would not survive the lunar night.

Contact with the spacecraft was reestablished after it received telemetry from the lander at around 05:00 Eastern Time (10:00 UTC), JAXA announced via its dedicated SLIM account on X, formerly Twitter.

昨晩、コマンドを送信したところSLIMから応答がありました。SLIMは通信機能を維持しての月面での越夜に成功しました！昨晩はまだ月の昼で通信機器の温度が非常に高かったことから短時間の運用のみで通信を終了しています。今後、温度が十分に下がったところで観測を再開できるように準備を進めます。 pic.twitter.com/dGbBkAAK1H
— 小型月着陸実証機SLIM (@SLIM_JAXA) February 26, 2024

The temperature of the communication equipment was extremely high due to the sun being high over the landing area. Communication was then terminated after only a short period of time.

The SLIM team is now preparing to conduct observations with SLIM's multiband spectroscopic camera (MBC) later in the lunar day. The instrument was designed to ascertain the composition of the lunar surface and could provide insights into the moon's history.

Sunset over Shioli crater, on the rim of which SLIM landed, will occur on Feb. 29, Space News reported.

(Photo: @SLIM_JAXA/X)

Not Designed for Lunar Night

SLIM was not designed to survive the deep cold of lunar night, as temperatures fall below -130 degrees Celsius during the roughly 14-Earth-day lunar nighttime, which could damage electronics.

Other spacecraft have used radioscope heater units to provide heating during lunar nights to allow prolonged operations.

SLIM - also referred to as Japan's "Moon Sniper" for its main objective of making a precise landing - touched down on the Moon on Jan. 19, although it was flipped upside down. Nevertheless, the feat made Japan one of the few nations to have successfully made a lunar landing after the United States, the Soviet Union, China, and India.

The landing of SLIM was followed a few weeks later with Intuitive Machines' Nova-C lander named "Odysseus," which was later revealed to be tipped over on its side.

JAXA's SLIM project manager, Shinichiro Sakai, said that his team has been conducting a detailed investigation into the cause of the engine malfunction after one of its two thruster nozzles fell off the spacecraft and has been considering making future countermeasures.