Elon Musk's private space company SpaceX is planning to send two unnamed tourists around the Moon in 2018.

Entrepreneur and futurist Elon Musk has announced that his private space company SpaceX would send two unnamed customers on a journey around the Moon next year.

The private space tourists have already paid a significant deposit towards the cost of the flight, which would see humans returning to the Moon for the first time since Gene Cernan left the final footprints on the Earth's only natural satellite as part of NASA's Apollo 17 mission 1972.

Although the two SpaceX customers will not actually land on the Moon, the trip in the company's Dragon 2 capsule would take them around the far side of the Moon before returning them back to the Earth.

There is some scepticism in the space community that SpaceX will manage this ambitious mission by 2018.

In a statement put out by NASA, SpaceX was reminded of its contractual obligations to the government space agency that it will "return the launch of astronauts to the US soil and continue to successfully deliver supplies to the International Space Station".

To date, only 24 people have ever been around the Moon, and just 12 have walked on its surface. The first living organisms to go around the Moon included a pair of steppe tortoises, sent by the then-Soviet Space Agency on the Zond 5 mission in 1968.