Startup ispace's Hakuto-R Mission 1 lander, which was supposed to touch down on the moon's surface on Tuesday most likely crashed while it tried to land, according to ispace Chief Executive Takeshi Hakamada.
"We lost the communication, so we have to assume that we could not complete the landing on the lunar surface."
The Japanese M1 lander was launched four months ago on a SpaceX rocket.
If it successfully landed, it would have deployed a rover and tested the performance of an experimental solid-state battery on the moon.
The startup says the lander already completed eight out of 10 mission objectives in space already, providing valuable data for the next landing attempt in 2024.
Tuesday's failure marks the second setback this week for private space development, after SpaceX's Starship rocket exploded minutes after soaring off its launch pad.
Only the United States, the former Soviet Union and China have successfully landed spacecraft on the moon, with attempts in recent years by India and a private Israeli company ending in failure.
Japan's top government spokesperson Hirokazu Matsuno said the country wants ispace to "keep trying" as its efforts were significant to the development of a domestic space industry.
Japan aims to send Japanese astronauts to the moon by the late 2020s, but it's suffered setbacks recently, including its new H3 rocket failing during its debut launch in March.
