SpaceX plans to launch two paying passengers on a tourist trip around the moon next year, the company said on Monday.
It said it will use a spaceship under development for NASA astronauts and a heavy-lift rocket yet to be flown.
SpaceX CEO Elon Musk told reporters his company was tentatively aiming for late 2018 to launch the first privately-funded tourist flight beyond the orbit of the International Space Station.
Musk declined to identify the customers or say how much they would pay to fly on the week-long mission, except to say that it is "nobody from Hollywood."
Market for space tourism
Musk said that two prospective space tourists, who know each other, have put down a "substantial" deposit and would undergo "extensive training before going on the mission."
"I think there's a market for one or two of these per year," he said, estimating that space tourist fares charged by SpaceX could eventually contribute 10 to 20 percent of the company's revenue.
The lunar venture would fly some 480,000 to 640,000 kilometres (300,000 to 400,000 miles) from Earth past the moon before Earth's gravity pulls the spacecraft back into the atmosphere for a parachute landing.
That trajectory would be similar to NASA's 1968 Apollo 8 mission beyond the moon and back.
Musk also said that if NASA decides it wants to be first in line for the lunar flyby mission, the US space agency would get priority.