Japan's Moon lander makes it through another lunar night

A post on social media from the lander's X account confirmed that once more, SLIM had defied the odds and snapped a picture of the lunar surface using its navigation camera.

SLIM was revived a few weeks ago, after a second lunar night. However, with telemetry showing that some of the electronics (temperature sensors) and battery cells were malfunctioning, the chances of the lander making it through a third lunar night seemed remote.

Yet against all odds, SLIM has stirred once more on the lunar surface despite lacking heaters to keep its electronics warm.

Spacecraft designed to survive extreme cold are usually constructed with heaters to keep electronics toasty. The surface temperature on the Moon can drop below −150°C, and the temperature in some craters can get as low as −247°C.

According to SLIM's social media presence: "SLIM has maintained main functionality even after three nights on the Moon, which was not anticipated in the design!

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"SLIM's condition will be monitored to clarify areas where deterioration has progressed due to the day and night environments, and where there is less susceptibility."

SLIM was only designed to last until the end of its first lunar day on the Moon's surface. The mission was initially declared a "minimum success" because the lander tipped onto its side during the landing, meaning that it could not achieve all the intended goals.

Despite this, SLIM has exceeded all endurance expectations and come around after a third lunar night.

JAXA gave no indication as to whether SLIM might survive a fourth lunar night or the state of the lander's electronics. At the start of April, hopes that a third night might be survivable were tempered with a warning that "the sensors and other functions are gradually being lost."

As we said in our earlier coverage: "Here's to as many more lunar sunrises as you can manage." ®