In this handout image provided by the European Space Agency (ESA) and NASA, the International Space Station and the docked space shuttle Endeavour orbit Earth during Endeavour's final sortie on May 23, 2011 in Space. Italian astronaut Paolo Nespoli captured the first-ever images of an orbiter docked to the International Space Station from the viewpoint of a departing vessel as he returned to Earth in a Soyuz capsule. (Photo by Paolo Nespoli - ESA/NASA via Getty Images)

Space Shuttle Atlantis lands at the Kennedy Space Center July 21, 2011 in Cape Canaveral, Florida. The landing brings to a close the 30-year era of the space shuttle program that began in 1981, and has included 135 missions. (Photo by Bill Ingalls/NASA via Getty Images)

European Space Agency astronaut Tim Peake will return home after a six-month long mission on the International Space Station,on June 18, 2016. Peake was the first British ESA astronaut to visit the ISS and captured hundreds of photographs of the Earth during his mission. Here: “Lots of sun-glint right now during our whole orbit – we haven't seen a sunset for over 3 days”, he wrote. (Photo by Tim Peake/ESA/NASA)

A British space-exploration company has revealed its aim to fly the public to the moon from 2015 – providing they have £100m for a ticket.

Photo: Jenn Sander from Red Robin PR, wearing a spacesuit once worn by US Astronaut Peggy Whitson, sits inside a re-entry capsule owned by Excalibur Almaz outside the Queen Elizabeth II Centre on June 19, 2012 in London, England. The company today announced their plan to fly people to the moon on what is the 40th anniversary year of the Apollo 17 moon landing. (Photo by Rosie Hallam)

Space shuttle Atlantis launches from pad 39A on July 8, 2011 at the NASA Kennedy Space Center in Cape Canaveral, Florida. The launch of Atlantis, STS-135, is the final flight of the shuttle program, a 12-day mission to the International Space Station. (Photo by Bill Ingalls/NASA via Getty Images)

Police officers with a sniffer dog check a railway as the Soyuz MS spacecraft for the next International Space Station (ISS) crew of Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan is ready to be transported from an assembling hangar to the launchpad ahead of its launch scheduled on July 7, at the Baikonur cosmodrome in Kazakhstan July 4, 2016. (Photo by Shamil Zhumatov/Reuters)

Crowds gather and watch the launch of NASA space shuttle Endeavour from Kennedy Space Center on the beach May 16, 2011 in Cocoa Beach, Florida. (Photo by Roberto Gonzalez/Getty Images)

NASA space shuttle Atlantis in Earth orbit is seen during a Rendezvous Pitch Maneuver, or back flip to enable space station crew members to take high resolution digital pictures of the shuttle's heat shield before docking for the last time with the International Space Station July 10, 2011 in space. Atlantis has embarked on a 12-day mission to the International Space Station where it will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts. This will be the final launch of the space shuttle program, which began on April 12, 1981 with the launch of Colombia. (Photo by NASA via Getty Images)