Fifty years ago, President Eisenhower created Nasa. Since then, we've sent men to the moon and robots to Mars – but the dream of regular tourist flights into space has still not been realised

Journey into space, anyone? The bravest venture yet from Sir Richard Branson promises to take tourists beyond the earth's atmosphere. The price of weightlessness and a new view of the planet: £100,000. How many people have stumped up – and who's on the list?

WW: We're at $36m as we speak today and that's just over 250 people who have actually stumped up. They're a very diverse group. They are people like Philippe Starck the designer and Victoria Principal, the actress from Dallas days who's now a successful entrepreneur in the US. Professor Stephen Hawking is certainly doing his damnedest to prove to us that we can carry him.

Virgin Galactic president Will Whitehorn on the company's announcement:

Almost all have two characteristics in common: one, they have a scientific interest and bent; the other, that they all saw the moon landing in 1969, and they were told by their parents, as they watched, that one day they would go into space, and it stuck with them. The only alternative at the moment costs $20m, involves seven months' training and learning to speak Russian, and having to be a qualified scientist.

SC: If space travel is so promising, then why, in almost five decades of men in space, have fewer than 500 people actually made the journey, and the Americans have wound down Nasa from the days where it seemed to despatch a lunar mission every 10 minutes?

WW: Access to space has always been a government-denominated investment, and it hasn't kept pace with the change in human circumstances. Because space exploration has been based on ground-based rocketry, with its military origins, it is intrinsically unsafe for human beings to be launched, therefore only the bravest of the brave have been doing it, and in circumstances of a massive government investment – to the extent that every single shuttle launch costs $700m.

We're trying to develop a new type of space launch system here. Imagine you've done your three days' training, you've learnt how to use your safety equipment in the cabin, you've had some experience learning about weightlessness and g-forces: you get on board – hopefully on a sunny New Mexico morning – and you climb into a rocket that is underslung under the entirely carbon-composite mother ship, in your entirely carbon-composite spaceship. You're lifted to 50,000ft. You're then dropped, a rocket fires, and within six seconds you're doing the speed of sound, within about 20 seconds you're at nearly 3,000mph, and you climb up into space and you get up to about 70 miles above the earth.

SC: You promise "The most incredible experience of your life".

WW: Yes. You will see the curvature of Earth, you will see the blue planet, you will see the thinness of the atmosphere, you will see the blackness of space. You will also experience weightlessness – something that all the people that we surveyed really wanted to experience more than anything else. But equal to that is seeing planet Earth and that thin atmosphere of ours. You'll get a look at all of that, you'll get the chance to be in space in the true sense of the word, and then you'll come back again.

Coming back is an experience in itself. You'll get quite a lot of g-forces through your body on the way down. But you won't feel that too badly, because you'll be lying flat. And you'll drop straight into the atmosphere – we're not trying to fly you back in like an aircraft or a space plane would try to do.

Once you're at 50,000ft, we turn the spaceship back into a glider and you simply glide down to the airport. It's about a two-and-a-half-hour experience.

SC: I understand that people will get only six minutes of weightlessness. I reckon that works out at about £300 a second. Can't it last a bit longer than that?

WW: The answer is it could last longer, but it would be more expensive. We reckon this is exactly the right amount of time for a flight. If you went a lot higher, you would increase the g-forces for coming down. So you'd be decreasing the safety aspects.

SC: New technology involves risk, space travel most certainly does. How can you manage the dangers?

WW: We're trying to take the riskiest things out of the equation. Ground-based rocketry involves firing a massive explosion under somebody to leave the planet – we've eliminated that. So you're launching in a very safe environment. We've hopefully eliminated some of the risks of re-entry, which is another of the most dangerous aspects.

We believe that this will be thousands of times safer than any previous human flights into space.

SC: Are we nearly there yet?

WW: Well, we're nearly there in the sense that Monday 28 July will mark the unveiling of the mother ship and the beginning of the test flying programme; named after Richard Branson's mother, it's going to be called Eve.

The spaceship is very nearly complete and will be underslung under the mother ship once it's done its first test flying programme in 2009. And when we and the Federal Aviation Administration are ready we will open it for commercial flight.

SC: Would it be, for example, within 40 years of the first moon landing in July 1969 – so about a year from now?

WW: I'd love to think that we could at least coincide the first test flight into space with that. I don't know yet if that will be possible. We've been very straightforward with our customers, we never make a promise we can't keep. But certainly within a few years we'll be test- flying into space with the world's first private, non-government subsidised space launch system.

SC: You talk about the thinness of the atmosphere, and in your publicity material you say it looks worryingly fragile. Many people would agree with that, including the objectors who would sum up Virgin Galactic in two words: "environmental disaster".

WW: That's rubbish. The fact is that, over 10 years, this entire programme, if we only achieved it for space tourism, would have less environmental impact than a single shuttle launch. More importantly, everything that we're going to do in space in the future is crucial to mankind's survival. We have to find better and more environmentally friendly ways to get there. And this system is the beginnings of a system that could allow people to go around the planet without using the atmosphere at all.

SC: So rather than just flying from Spaceport New Mexico to Spaceport New Mexico, you will be able to fly, maybe, people from London to Sydney?

WW: This system is theoretically capable of being expanded to take people around the planet, outside the atmosphere. But we will not be given the funds to invest in that unless we can prove that the first phase works. The space tourists we take up in the beginning are going to be part of that process of proving that we can do something safely and efficiently, in a way that's never been done before.

SC: Are we going to see, any time in your lifetime, man returning to the moon, and will Virgin Galactic be helping?

WW: I think we are very likely to see man returning to the moon. I think it's a shame in some ways because I can't quite understand why we are going to rebuild what we built so well in the 1960s. If you want the dreamer in Will Whitehorn answering the question, if I was going to run a space programme now, I would give people who wanted to volunteer for it the opportunity to go to Mars direct from this planet, and not come back. They would stay there. And they would take with them the equipment for their survival, for long enough till the next mission could reach them, and possibly think about bringing them back.

You can listen, free, to the full version of this interview clicking the audio-player above.

Race for space

* 29 July 1958: President Eisenhower signs the National Aeronautics and Space Act, establishing the National Aeronautics and Space Administration (Nasa).

* 11 October 1958: First Nasa launch from Cape Canaveral: Pioneer 1.

* 12 April 1961: Yuri Gagarin becomes the first human to go into space, in the Vostok I spacecraft. Flight lasts 108 minutes.

* 5 May 1961: Alan Shepard becomes the first American in space aboard Freedom 7.

* 20 February 1962: John Glenn becomes the first American to orbit the earth, in the Friendship 7 Mercury spacecraft.

* 20 July 1969: First moon landing. Neil Armstrong and Edwin "Buzz" Aldrin become the first and second humans on the moon, arriving aboard Apollo 11.

* 28 January 1986: Space Shuttle Challenger blows up just after take-off. All crew members die.

* 20 February 1986: Russia launches the core module for the Mir Space Station.

* 24 April 1990: Hubble telescope launched from Space Shuttle Columbia.

* 20 November 1998: First part of the International Space Station – the Russian-built Zarya module – is launched.

* 28 April 2001: The first space tourist, American Dennis Tito, spends eight days on the International Space Station. He pays £14m for the privilege.

* 1 February 2003: The crew of the Space Shuttle Columbia perish when it breaks up on re-entry.