Tickets for the historic first flight will cost about £150m, with the price falling to about £50m after 10 years. Adventurers will have to submit to six months of full-time training with the Californian company XCorp.

As well as marketing to rich space fanatics, the company is in talks with three emerging economies who want the prestige of sending someone to space without the expense of developing their own space programmes.

The company also hopes to drive revenues by emblazoning adverts across its space station, conducting research for universities and pharmaceutical companies and allowing other expeditions – including government astronauts from countries like China – to rent the space station.

But space brings a new universe of risks for investors.

“Everyone has to remember that space is aggressive, it is not our mother planet,” said Valery Tokarev, a Russian cosmonaut who advises the company.

After two journeys into space, he has one key lesson: “If you make a mistake in space, it will kill you.”

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