Enlarge / Elon Musk speaks as Yusaku Maezawa, founder and president of Start Today Co., looks on at an event at the SpaceX headquarters in Hawthorne, California, in 2018. (credit: Patrick T. Fallon/Bloomberg via Getty Images)

On Friday night the dearMoon project—a plan to launch a Japanese billionaire and 10 other 'crew members' on a circumlunar flight aboard SpaceX's Starship vehicle—was abruptly canceled.

"It is unfortunate to be announcing that 'dearMoon', the first private circumlunar flight project, will be cancelled," the mission's official account on the social media site X said. "We thank everyone who has supported us and apologize to those who have looked forward to this project."

Shortly afterward the financial backer of the project and its 'crew leader,' Yusaku Maezawa, explained this decision on X. When Maezawa agreed to the mission in 2018, he said, the assumption was that the dearMoon mission would launch by the end of 2023.