A US firm that has already sent two wealthy space tourists into orbit is now offering a trip around the moon.
It costs $100m but conditions will be cramped for the voyage in Soyuz
Virginia-based Space Adventures was on Wednesday unveiling a deal with Russian space officials for the $100m voyage.
Two passengers will join a Russian pilot for a trip lasting from 10 to 21 days, depending on whether they stop at the International Space Station.
In 2001, financier Denis Tito became the first space tourist, spending $20m on what proved a controversial tour.
Mr Tito's visit to the ISS sparked a row between Nasa and the Russian space agency.
Space Adventures says its research suggests that between 500 and 1,000 people around the world could afford to undertake the trip, which could go ahead as early as 2008.
The passengers would be sent up in a Russian Soyuz spacecraft, a vehicle that would be cramped and quite uncomfortable for an extended trip, according to space experts.
Because the craft does not have the power to reach the moon unaided, it would have to dock with a booster rocket sent up separately which would propel it towards the moon.
Eric Anderson, CEO of Space Adventures, says the timing of the announcement - a day after the landing of the Space Shuttle - was not a dig at Nasa.
"We believe private space flight and space exploration can go hand in hand," he told the New York Times newspaper.
Another Space Adventures client, Greg Olsen, has been undergoing training for a voyage to the ISS in October. He will be the third space tourist.
South African Mark Shuttleworth visited space in 2002.