Holidaymakers will be able to visit space for as little as £7,000 within the next two decades, a veteran astronaut has predicted. Dr Donald Thomas, who took part in four missions on the Columbia and Discovery shuttles, said as more space tourism companies such as Virgin Galactic and SpaceX arrived into the market the price would no longer become a luxury only the super-rich can afford.

"I expect that in the next couple of years Virgin Galactic will begin their sub-orbital space excursions, allowing tourists the chance to see the Earth from 85 miles up, viewing the curvature of the Earth and the total blackness of the sky in space," he is quoted as saying in The Times.

"Prices for these trips are approximately $220,000 (£153,000, €197,000). While still expensive, the trips are much more affordable than paying the Russians $65m for a trip to the ISS (International Space Station). I also expect that SpaceX, Boeing and a few other companies will follow when tourist trips to and from the ISS are firmly established.

"It is difficult to predict future prices for these trips, but I would anticipate within a decade or two prices will drop to the $10,000 to $20,000 range."

A seat aboard a Virgin Galactic spacecraft has so far been something only the world's wealthiest can afford, currently costing $250,000. A-list celebrities including Leonardo DiCaprio, Angelina Jolie and Lady Gaga have all joined the 700 people who have already bought tickets to become some of the world's first space tourists.

donald thomas
Dr Donald Thomas has logged more than 1,000 hours in space and flew four missions in Nasa's Columbia and Discovery shuttles Nasa

But Sir Richard Branson's company has suffered setbacks since it was established in 2004, with the expected spring 2015 launch date for the first passenger flights delayed due to a fatal crash. In October 2014, the company's SpaceShip Two craft, VSS Enterprise, broke apart in midair while undertaking the company's fourth rocket-powered test flight.

An investigation later found the crash was caused by human error after co-pilot Michael Alsbury, who was killed in the accident, unlocked the spaceplane's breaking system too early.

Branson vowed to rebuild and in February Virgin Galactic unveiled its replacement spacecraft, the VSS Unity, at its Mojave Spaceport in California. It is expected to conduct its first test flights later this year.

Dr Thomas, who spent more than 1,000 hours in space during the 1990s and is now an ambassador for Nasa's Kennedy Space Center, said he was confident Virgin Galactic would overcome setbacks in the next few years.

"I believe they are just a few years away from beginning their commercial space flights," he said. "Right now they are redesigning their vehicles after their accident a year or two ago. Once the needed redesigns are completed, tested, and the safety of the system verified, commercial flights will commence."