YUSAKU MAEZAWA is a Japanese fashion billionaire. If he gets his way, in 2023 he will become the first person to visit the Moon since Eugene Cernan, an American astronaut, left in 1972. Unlike Mr Cernan, Mr Maezawa will not land. Instead, he will zoom round the Moon aboard a spaceship built by SpaceX, an American rocketry firm. That, at least, was the plan announced on September 17th by Elon Musk, SpaceX’s boss. Whether it will happen is another question. SpaceX is already late with plans to fly astronauts to the International Space Station, which is far easier. A previous lunar trip scheduled for this year has been shelved. And the rocket that will do the job does not yet exist. Even Mr Musk was careful to describe the timeline as aspirational.