Japanese billionaire Yusaku Maezawa cancelled his "dearMoon" mission, which the project said would have been the first private flight around the moon, the mission announced on Saturday.
The team had originally aimed to make the circumlunar flight with celebrities on board by the end of last year but that became "unfeasible", the mission said in a statement on its website.
"Without clear schedule certainty in the near-term, it is with a heavy heart that Maezawa made the unavoidable decision to cancel the project," it said. "To all who have supported this project and looked forward to this endeavor, we sincerely appreciate it and apologize for this outcome."
In a separate post on the mission website, Maezawa suggested the cause of the cancellation was uncertainty over the project development, saying he signed the contract in 2018 based on the assumption the launch would come by the end of 2023.
"It's a developmental project so it is what it is, but it is still uncertain as to when Starship can launch," Maezawa said.
"I can't plan my future in this situation, and I feel terrible making the crew members wait longer, hence the difficult decision to cancel at this point in time."
Elon Musk's SpaceX named Maezawa, the colourful founder of Japanese online fashion store Zozo Inc (3092.T), its first private passenger in 2018.
Three years later he was the first private passenger to visit the International Space Station in more than a decade, launching on a Soyuz rocket.
In 2022, Maezawa announced that K-pop star TOP and DJ Steve Aoki would be among the eight crew members he planned to take on the dearMoon mission.
In November he said the flyby mission would be delayed until this year or later.
