Photo: JAXA via Agence France-Presse In this photo taken and made available by the Japan Space Agency on September 7, 2023, the H-IIA rocket lifts off from the Tanegashima Space Center for its lunar mission.
Mari Yamaguchi – Associated Press and The Canadian Press in Tokyo
Japan became the fifth country in history to reach the Moon when its spacecraft touched down on the lunar surface early Saturday, officials said. But a power problem means the mission could be compromised.
Officials also said they needed more time to determine whether the spacecraft, which was not carrying astronauts, had successfully completed an accurate moon landing — one of this mission's priorities .
Hitoshi Kuninaka, director of the Institute of Space and Astronautical Sciences, said he believed the rovers were launched from the spacecraft and data was transmitted to Earth from the “SLIM.” (“Smart Lander for Investigating Moon”).
But he said the SLIM's solar battery was not producing electricity and the ship's battery life would only last a few hours longer. He said the priority now was for the craft to collect as much lunar data as possible from the remaining battery.
Japan therefore follows the United States, the Soviet Union, China and India in their quest for the Moon.
Mr. Kuninaka believes that the Japanese space program has achieved at least “minimal” success.
The SLIM craft landed on the Moon on Saturday around 12:20 a.m. Tokyo time.
The wait for news was high after the Japanese Space Agency's (JAXA) Mission Control initially said SLIM was on the lunar surface, but was still checking “its status.” . No further details were given until a press conference nearly two hours later.
For the mission to be considered fully successful, agency officials must confirm whether SLIM made an “accurate moon landing.” Mr. Kuninaka said that even if more time was needed, he personally believes that this precise moon landing was likely accomplished, based on his observation of the data showing the spacecraft's movement until landing.< /p>
SLIM, which aimed at a very small target, is a lightweight spacecraft the size of a passenger car. It used “precision landing” technology that promises far greater control than any previous moon landing.
While most previous probes used landing zones around 10 kilometers wide, SLIM aimed for a target just 100 meters away. This project is the culmination of two decades of JAXA work on precision technology.
As the spacecraft descended, Japan Aerospace Exploration Agency mission control reported that everything was going according to plan and later stated that SLIM “was on the lunar surface.” But it was not specified from then on whether the moon landing was successful.
A “precision moon landing” technique
SLIM began its descent at midnight Saturday, and within 15 minutes it was about 10 kilometers above the lunar surface, according to the space agency.
At an altitude of five kilometers, the lander was in vertical descent mode, then at 50 meters, SLIM was supposed to make a parallel movement to find a safe landing point, JAXA said. About thirty minutes after its presumed moon landing, JAXA said it was still checking the condition of the craft.
The primary objective of the mission is to test new landing technology that would allow lunar missions to land “where we want them, rather than where it is easiest to do so.” , JAXA said. If the landing is successful, the spacecraft will search for clues to the origin of the Moon, including analyzing minerals with a special camera.
The SLIM, equipped with a cushion to cushion the impact, was to land near the Shioli crater, near a region covered in volcanic rock.
This closely watched mission took place just 10 days after the failure of a lunar mission led by a private American company, when the craft experienced a fuel leak hours after the rocket's launch.
SLIM had been launched on a Mitsubishi “Heavy H2A” rocket in September. The spacecraft first orbited Earth and entered lunar orbit on December 25.
Japan hopes that success will allow it to regain confidence in its space technology after several failures. A spacecraft designed by a Japanese company crashed during an attempted moon landing in April, and a new flagship rocket failed on its first launch in March.
JAXA has a good record of “difficult landings”. Its Hayabusa2 spacecraft, launched in 2014, landed twice on the 900-meter-long asteroid Ryugu, collecting samples that were returned to Earth.
SLIM carries two small autonomous probes: the LEV-1 and LEV-2 rover vehicles, which were to be released just before the spacecraft landed. LEV-1, equipped with an antenna and a camera, was to record the SLIM moon landing. LEV-2, for its part, is a ball-shaped rover, equipped with two cameras, designed by JAXA in collaboration with Sony, the toy manufacturer Tomy and Doshisha University.