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 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's nobody from Hollywood".
"Like the Apollo astronauts before them, these individuals will travel into space carrying the hopes and dreams of all humankind, driven by the universal human spirit of exploration.
"We expect to conduct health and fitness tests, as well as begin initial training later this year."
The first mission would be unmanned, and the next one - with crew - was expected in the second quarter of 2018, the billionaire entrepreneur and inventor said.
He also said the first passengers "are entering this with their eyes open, knowing that there is some risk here".
"They're certainly not naive, and we'll do everything we can to minimise that risk, but it's not zero."
The space tourists would make a loop around the Moon, skimming the lunar surface and then going well beyond, Mr Musk said.
The mission will not involve a lunar landing.
If Nasa decided it wanted to be first to take part in a lunar flyby mission, then the agency would have priority, Mr Musk said.
The US has not sent astronauts to the Moon since the early 1970s.
SPACEX TO SEND PRIVATELY CREWED DRAGON SPACECRAFT BEYOND THE MOON NEXT YEAR
We are excited to announce that SpaceX has been approached to fly two private citizens on a trip around the moon late next year. They have already paid a significant deposit to do a moon mission. Like the Apollo astronauts before them, these individuals will travel into space carrying the hopes and dreams of all humankind, driven by the universal human spirit of exploration. We expect to conduct health and fitness tests, as well as begin initial training later this year. Other flight teams have also expressed strong interest and we expect more to follow. Additional information will be released about the flight teams, contingent upon their approval and confirmation of the health and fitness test results.
Most importantly, we would like to thank NASA, without whom this would not be possible. NASA’s Commercial Crew Program, which provided most of the funding for Dragon 2 development, is a key enabler for this mission. In addition, this will make use of the Falcon Heavy rocket, which was developed with internal SpaceX funding. Falcon Heavy is due to launch its first test flight this summer and, once successful, will be the most powerful vehicle to reach orbit after the Saturn V moon rocket. At 5 million pounds of liftoff thrust, Falcon Heavy is two-thirds the thrust of Saturn V and more than double the thrust of the next largest launch vehicle currently flying.
Later this year, as part of NASA’s Commercial Crew Program, we will launch our Crew Dragon (Dragon Version 2) spacecraft to the International Space Station. This first demonstration mission will be in automatic mode, without people on board. A subsequent mission with crew is expected to fly in the second quarter of 2018. SpaceX is currently contracted to perform an average of four Dragon 2 missions to the ISS per year, three carrying cargo and one carrying crew. By also flying privately crewed missions, which NASA has encouraged, long-term costs to the government decline and more flight reliability history is gained, benefiting both government and private missions.
Once operational Crew Dragon missions are underway for NASA, SpaceX will launch the private mission on a journey to circumnavigate the moon and return to Earth. Lift-off will be from Kennedy Space Center’s historic Pad 39A near Cape Canaveral – the same launch pad used by the Apollo program for its lunar missions. This presents an opportunity for humans to return to deep space for the first time in 45 years and they will travel faster and further into the Solar System than any before them.
Designed from the beginning to carry humans, the Dragon spacecraft already has a long flight heritage. These missions will build upon that heritage, extending it to deep space mission operations, an important milestone as we work towards our ultimate goal of transporting humans to Mars.
NASA Statement About SpaceX Private Moon Venture Announcement
The following is a statement on SpaceX’s announcement Monday about a private space mission around the moon:
“NASA commends its industry partners for reaching higher.
“We will work closely with SpaceX to ensure it safely meets the contractual obligations to return the launch of astronauts to U.S. soil and continue to successfully deliver supplies to the International Space Station.
“For more than a decade, NASA has invested in private industry to develop capabilities for the American people and seed commercial innovation to advance humanity's future in space.
“NASA is changing the way it does business through its commercial partnerships to help build a strong American space economy and free the agency to focus on developing the next-generation rocket, spacecraft and systems to go beyond the moon and sustain deep space exploration.”