Japan's space agency suffered a setback in its plans to further its lunar program Tuesday as it gave up on landing the country's ultra-small space probe on the Moon due to a failure to stabilize communication with the lander launched last week.
The Japan Aerospace Exploration Agency said the Omotenashi lander could not receive transmissions from Earth to correct its trajectory and position, after its solar power cells kept facing away from the sun.
Tatsuaki Hashimoto, who led the project, called the development "deeply regrettable" at a press conference following the decision to forgo the Moon landing.
Development costs for the probe were 800 million yen ($5.6 million), he said.
JAXA had hoped the box-shaped lander, measuring 11 centimeters in length, 24 cm in width, and 37 cm in height and weighing 12.6 kilograms, would become the country's first probe to land on the lunar surface.
The agency said it also considered altering its plans by getting the probe to fall onto the Moon's surface at a speed greater than the 180 kilometers per hour originally anticipated, but attempts to regain contact with it by Tuesday were not successful.
A second attempt at the lunar landing will not be feasible because the probe has now entered the sun's orbit, JAXA said. Before the launch, the agency had said the mission's probability of success was 60 percent.
The Omotenashi, touted as the world's smallest lunar lander, was launched on Nov. 16 from the National Aeronautics and Space Administration's Kennedy Space Center in Florida on the U.S. megarocket Space Launch System.
After the launch, the lander was successfully separated from the rocket and started to travel toward the Moon.
But its solar cells failed to function as its body rotated away from the sun once every four to five seconds, which is eight times faster than the assumed limit.
Waiting until the solar cells recovered on Tuesday or later would have meant losing the opportunity to enter a lunar orbit and land on the Moon, the agency said.
JAXA has established a special team to investigate the cause of the failure, and it is also looking into why the probe's position became irregular, among other issues.
Hashimoto also said it appears the probe's solar panels will face the sun in March 2023, thereby leaving open the possibility of regaining contact with it.
The Omotenashi's functions include being able to measure radiation levels in space. If it can successfully obtain information from deep space, from which little data exists, its findings could be put to use in future manned missions.
The agency said it will also engage in tests to ignite its onboard rocket motor.
Since Japan's orbiting satellite Kaguya launched in 2007 helped create 3D maps of the Moon, the country has fallen behind other nations' initiatives to create lunar probes, and the Omotenashi had been expected to mark its return to the field.
Other Moon-related projects being headed by JAXA include a fiscal 2023 attempt at a soft landing on the Moon using the SLIM lunar lander, and a search for water on the Moon's southern pole in fiscal 2024 or later.
Some JAXA officials voiced concerns that the latest setback could affect subsequent lunar projects.
The United States and Japan are deepening their cooperation in space, and affirmed earlier this year their "shared ambition" to realize a future Moon landing by a Japanese astronaut.