Japan shuts down SLIM lunar lander after its battery power drops to 12%: NPR

The Japan Aerospace Exploration Agency (JAXA) shut down its lunar lander days after its historic arrival due to energy concerns. Here, Japan Aerospace Exploration Agency leaders brief the media on the successful moon mission and the lander's solar cell problem on Friday.

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The Japan Aerospace Exploration Agency (JAXA) shut down its lunar lander days after its historic arrival due to energy concerns. Here, Japan Aerospace Exploration Agency leaders brief the media on the successful moon mission and the lander's solar cell problem on Friday.

Gigi Press/AFP via Getty Images

Will the Japanese lunar lander get a charge from the sun or will its mission end when its battery runs out?

Japan's space agency now faces that question, even as it enjoys becoming only the fifth country to achieve a soft landing on the moon. As it celebrated the milestone on Friday (Eastern time), the agency also announced that its spacecraft called SLIM, Smart Lander for Investigating Moon, appeared unable to get electricity from its solar cell.

The Japan Aerospace Exploration Agency, or JAXA, said its engineers would study the problem, even as it raced to download data and images from the lunar mission. Three days later, the lander has now been sealed.

“At a battery level of 12%, the battery was disconnected (as planned),” Japan Aerospace Exploration Agency He said Monday morningAdding that the lander was shut down to leave enough energy for a possible restart. The agency expressed optimism that the lander might return to work.

“According to telemetry data, the solar cells of the SLIM probe are facing west,” the Japan Aerospace Exploration Agency said. “So if sunlight starts shining on the moon from the west, there is potential for power generation, and we are preparing for recovery.”

The Japan Aerospace Exploration Agency also confirmed that the SLIM mission, which succeeded in accurately targeting the landing site on the moon's surface, sent a set of information and images to Earth before its battery ran out.

“We are currently conducting a detailed analysis, and we are pleased to see that we have obtained a lot of data,” the agency said.

The lander will have to survive the Moon's extreme cold

The Japan Aerospace Exploration Agency has not specified a time frame in which the Sun might be in a suitable position to power the energy-hungry lander. But a recent comment from Hitoshi Kuninaka, director general of the Japan Institute of Aerospace and Astronautical Science, or ISAS, has provided some clues.

The spacecraft is designed to enter a kind of “sleep mode” in the event of a power outage, Kuninaka said Friday, citing the moon's long days and nights. One lunar day lasts about 29.5 Earth days, with about two weeks of hot sunlight and extreme darkness – although As NASA notesdefinitions of “day” vary widely.

“So, if the spacecraft survives a 200-degree night, it can bounce back within two weeks,” Kuninaka said. He added that while SLIM was designed to allow for this possibility, it was not a major factor in its design.

“The original purpose of SLIM…is not to conquer the night,” Kuninaka said. “So we just have this wishful thinking that SLIM will be able to survive the night.”

“If the light is on the solar cell, the receiving equipment will start working again automatically, and then we can send a command from Earth to wake up the system again.”

An update is expected later this week

The Japan Aerospace Exploration Agency plans to hold a press conference later this week to share data about the moon mission. The update will likely include a more detailed diagnosis of SLIM's solar cell and its less-than-ideal position — in this case, meaning the way the rover is oriented on the lunar surface.

“Although the situation after the landing did not go as planned, we are happy about it [achieved] “We are very happy with the successful landing,” the Japan Aerospace Exploration Agency said on Monday.

Crowds of people watched the landing, which occurred in the early hours of Saturday morning in Japan. A live broadcast from the Japan Aerospace Exploration Agency (JAXA) showed the lander carefully maneuvering toward the lunar surface, as the SLIM's altitude dropped to zero. Then he stayed in touch, communicating from the moon.

When they announced the breakthrough, Japan's top space officials appeared somewhat muted, as the lander's power capabilities loom large over the mission. One reporter even asked them why they looked grimacing instead of smiling.

“This will be difficult under the current circumstances,” said Masaaki Fujimoto, vice president of ISAS. Asahi Shimbun. He added: “If things had gone according to plan, I would be smiling now, but I need to know the situation [of the lander] as soon as possible.”