A Japanese robotic lander touched down on the moon's surface on Friday, but immediately suffered a power malfunction of some kind that prevented its solar cells from generating the electricity needed to keep it alive in the harsh lunar environment.
As a result, mission managers said, the apparently intact Lunar Exploration Intelligent Lander, or SLIM, is expected to exhaust its batteries within hours of landing, leaving it incapacitated and unable to receive commands or transmit telemetry and scientific data to Earth. .
There is hope that the probe will “wake up” at some point, assuming that the spacecraft descends in the wrong direction and that the angle between the sun and the solar cells improves enough over time to generate enough power, but officials said that is by no means certain.
“The SLIM was communicating with the ground station and receiving commands from Earth accurately and the spacecraft was responding to these in a normal way,” Hitoshi Kuninaka, director general of the Japan Aerospace Research Agency, or JAXA, told reporters. Translated statements.
“However, it appears that solar (cells) do not generate electricity at this time. Since we are unable to generate electricity, the process is done using batteries. … We are trying to (get stored data) back to Earth, and we are making efforts to maximize Scientific (return).”
He said the battery power would be exhausted before the day was over.
Only the United States, Russia, China and India were able to successfully land spacecraft on the moon. Three privately funded landing missions were launched as commercial ventures, but all three failed.
Demise of the Peregrine lunar lander
at recent days,built by Pittsburgh-based Astrobotic, was stranded in a highly elliptical Earth orbit after a valve malfunction caused its fuel tank to rupture. January 8th. The company's flight controllers directed the spacecraft to return to Earth's atmosphere, where it burned up Thursday afternoon.
During a separate press conference on Friday, Astrobotic CEO John Thornton praised the company's flight controllers for managing to keep the spacecraft alive as long as possible, activate its science payloads, and fire thrusters to redirect the vehicle and collect data that will be fed back to the spacecraft. . Design and operation of the largest lunar lander – Griffin – scheduled for launch late this year.
“We will convene a review board with several experts from across the industry to take a hard look at this matter to find out exactly what happened,” Thornton said. “We are already evaluating what those impacts could be for the Griffin program to ensure that this type of anomaly never happens again.”
At the same time, he added: “We are also making sure that all the successes of the Peregrine mission are integrated into the Griffin program to ensure that Griffin is successful. … I am more confident now than ever that our next mission will be successful and we will land on the moon.”
Japan plans to land on the moon
The Japan Aerospace Exploration Agency's lunar lander was built to achieve two main goals: to demonstrate a high-precision lander system capable of guiding the rover to land within 100 meters, or about the length of an American football field, of its planned target; And testing an innovative lightweight design that allows smaller spacecraft to carry more sensors and instruments.
On Sept. 7 from Tanegashima Space Center in southern Japan, the 1,600-pound spacecraft slid into an initially elliptical orbit around the moon's poles on Christmas Day and moved to a 373-mile-high circular orbit earlier this month.
On Friday morning US time, the SLIM spacecraft began its final descent to the lunar surface from an altitude of about nine miles. Real-time telemetry showed the rover precisely following the planned path, stopping several times along the way to photograph the surface below and compare the view with on-board maps to ensure a high-precision predicted landing.
The final stages of the descent appear to be going smoothly. The SLIM flipped from horizontal to vertical orientation in time and slowly fell toward the surface. It was programmed to launch two small vehicles, known as LEV-1 and LEV-2, just a few feet from landing.
The probe's rear legs, which are designed to land on a slope, are expected to land first. The spacecraft is designed to lean forward slightly, lowering its front legs. The idea was to place the spacecraft on sloping terrain in an orientation that would maximize solar energy generation.
Telemetry indicated landing at 10:20 a.m. EDT, about 20 minutes after landing began. Japan Aerospace Exploration Agency officials did not immediately confirm receipt of the telemetry, raising concerns that the spacecraft may not have survived the landing.
But NASA Deep Space Networkwhich sends commands and receives data from spacecraft across the solar system, was receiving telemetry from SLIM or one of the small craft — or both — an hour after landing.
At the press conference following the landing, JAXA officials confirmed that flight controllers were receiving telemetry from both SLIM and LEV-1, which is designed to send data directly to Earth. The LEV-2 relays the data back through SLIM.
“We consider LEV-1 and LEV-2 to have successfully separated, and we are making an effort to obtain data at this time,” Kuninaka said.
As for SLIM, he said engineers suspected that solar cells mounted on the spacecraft's upper surface were damaged during landing given that other systems were operating normally after what he described as a “soft” landing.
“The spacecraft was able to transmit telemetry to us (after landing), which means that most of the equipment on the spacecraft is working, and is working properly,” he said. “The altitude from which the landing was made was ten kilometres. So if the landing had not been successful, there would have been a very high speed (collision). Then the spacecraft completely lost its function.
“But now, it's still sending data back to us correctly, which means our original goal of a soft landing was successful.”
But he said extensive data analysis would be needed to determine the spacecraft's position or orientation on the surface, to figure out what happened and to see how accurately the landing actually was.
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