US private rocket company SpaceX has announced that two private citizens have paid to be sent around the Moon.
The mission is planned for late 2018, SpaceX CEO Elon Musk said, adding that the tourists "have already paid a significant deposit".
"This presents an opportunity for humans to return to deep space for the first time in 45 years," he said.
The two unnamed people will fly aboard a spaceship which is set for its first unmanned test flight later this year.
Mr Musk said said the co-operation of America's Nasa space agency had made the plan possible.
He said the two passengers "will travel faster and further into the solar system than any before them".
Mr Musk declined to reveal their identities, only saying that they knew each other and that it was "nobody from Hollywood".
The US has not sent astronauts to the Moon since the 1970s.