How did you become so passionate about skydiving?

I used to have this recurring dream, which started when I was 8 years old. I would remember it vividly when I woke up. In the dream, I would step out onto the window sill of my house, and it would be pitch black outside, no moon nor stars nor lights of any kind. Then I would jump off the window sill and it seemed like I was floating on a big cushion of air. I never saw myself in the dream, I just had the feeling of floating or flying. I had that dream about once a month until I was 15, but by the time I was 16 it was coming about once a week.

It bothered me so much that I told my mother I had to do a parachute jump to find out if the sensation in the dream was real. All I wanted to do was the free-fall bit, but I found out you had to do the static-line stuff first. On my first jump the parachute was open almost as soon as I left the plane so there was no free fall to experience. It took another 15 or so jumps before I could see and feel everything, because there is such a sensory overload when you first start jumping. After that, I never had the dream again. It was directly responsible for getting me interested in skydiving.

How did you come by this idea to jump from the edge of space?

Several years ago I ran into a friend who said he was interested in doing a free-fall jump from the stratosphere and we decided to work on it together. We were going to do an unpressurised jump together from 45,000 feet, just to get the publicity going. Then my friend had a parachute accident which left him partially paralysed. After that I began to realise how massive a project skydiving from the stratosphere was going to be, and since he was out of the picture I began looking to some of my military contacts.

I was introduced to Shannon Friedel and Tullis Looney. Shannon is president of HALO Productions, a television production company that specialises in extreme sports, and Tullis is a skydiver instructor and pilot. The StratoQuest mission really took shape when Shannon was setting up a new reality adventure TV series called Global Fitness Challenge. One of the episodes involved a helium balloon race and a skydive from high altitude. They contacted me and asked if I would be interested in working with them. Since then we have hired NASA engineer Dominic Del Rosso, and now StratoQuest's primary mission is to prove that humans can safely return to Earth from even the very edge of the atmosphere.

The mission is a challenge - technically, physically and mentally. I love challenges. I get bored easily, so I love the mental, physical and emotional aspects of trying new challenges. But more than that, I want to push the envelope of knowledge about high-altitude environments and high-altitude escape systems. The mission will be remembered for many years to come. People will always be intrigued by space travel.

What do you hope to find out?

Shuttle crews do not have much time to prepare for bail-out emergencies. If they do manage to bail out, no existing equipment will ensure their survival above 100,000 feet. Our mission will help researchers understand how pressure suits, and humans, react at 130,000 feet. Nothing has been tested above 102,800 feet. It is difficult to say how useful this research will be for space programmes, although the research is needed for all high-altitude aircraft. The aim is to collect data that could allow people to escape from any vehicle outside the Earth's atmosphere. We will learn more about how to control rotation in a spacesuit during free fall. We will be testing how people and spacesuits hold up during acceleration and deceleration through the sound barrier and during supersonic flight, and in extremes of temperature. We will also be testing radar tracking and other communication technologies in these conditions.

Describe what will happen during the jump.

The balloon ascent will take about 2 1/2 hours to reach 130,000 feet under ideal conditions. The ride down from the stratosphere will take about 10 1/2 minutes - 5 1/2 minutes for the free fall and another 5 minutes after my parachute opens. If I bail out at 130,000 feet and nothing goes wrong, I will reach Mach 1 in 47 seconds. Once I hit an altitude of 100,000 feet the atmosphere will thicken, and atmospheric friction will start slowing me down.

My maximum free-fall speed will be around 1150 kilometres per hour, though because of the thinness of the atmosphere it will feel like only 4 kilometres per hour. The speed I reach will depend on my body position on the way down. If I go into a head-down dive I could go much faster, and I may reach a speed of Mach 1.3. I don't know whether I will create a sonic boom. At 130,000 feet it will be about 0 °C . Above 70,000 feet you are into the ozone layer and the air is relatively warm. But between 30,000 and 70,000 feet it will be colder - around -35 to -70 °C.

I will open the parachute at 7000 feet so that by the time I reach 5000 feet I will be under a full canopy - you need 2000 feet of leeway for this parachute to fully deploy. By this stage I will have slowed to a speed of around 240 kilometres per hour due to friction.

I will learn more about what will happen during the jump as we do the intermediate practice jumps. I suspect that I will be so busy during the ascent that I won't have much time to worry about it. And on the descent I will be very focused on flying me, keeping myself stable and being aware of the altitude, the things every first-jump student must do. The preparations will be so thorough that the jump may be almost an anticlimax. My jump will be televised for the Global Fitness Challenge show - I will be carrying cameras on my helmet and spacesuit.

The record for the highest free-fall jump is held by Joe Kittinger, the US air force captain who jumped out of a balloon at 102,800 feet in 1960. Kittinger went into a life-threatening spin on one of his stratospheric jumps and passed out before his parachute opened automatically. How much of a problem will spin be for you?

Back then it was easy to get into a spin because they didn't know enough about what caused them, let alone how to get out of one. I will have a small drogue parachute that will deploy if the sensors in my suit say I am exceeding a certain rate of rotation and will stop me from spinning. This is in the event that I become disoriented or confused, or in thick cloud cover. Of course, once the drogue is deployed the free fall ends and there goes the record. But if it saves your life, you can always try again. Another situation we are preparing for is an accidental deploy of the main or reserve parachute while I'm still at around 90,000 feet. If this happened, I would not have enough oxygen to ride the parachute to the ground, so I will have the means to cut it away.

How else will your mission compare with Kittinger's?

Kittinger went up in an enclosed, pressurised gondola. I am going up in an open-air, unpressurised gondola. I want the experience of seeing the curvature of the Earth and the blackness of space. No one has ever attempted going up this high in an open gondola before.

What kind of suit will you be wearing?

I will have a pressure suit. While I'm in the gondola it will be attached to five hoses providing life-support functions such as oxygen, water, heating and radio. I have to detach myself from these before I make the jump. Once in free fall the suit will have a limited internal life-support system, including an oxygen tank. The suit itself weighs only 10 kilograms, but once we've added all the other stuff it will weigh between 35 and 40 kilograms.

How does it feel when you are falling through the sky?

Free fall is like floating on a big cushion of moving air, like the air you feel when you stick your hand out of a car window, but much faster. For me the fun of it is the challenge of using the power of the air to control my body and doing manoeuvres during free fall, and then the challenge of precisely flying the canopy once it is open. I love flying, whether it's in free fall, under my parachute or in an airplane.

Is it addictive?

I could live if I couldn't fly or free fall. Life would not be as much fun, but I would survive and find new challenges.

Do you ever get scared?

I get scared if I get into an unexpected situation that I don't like, but you learn to respect the fear and listen to it. You reassess the situation and try to avoid what is creating the feeling of danger, or you find that you can safely work through it and conquer the fear.

Have you ever had an accident?

I have never had an accident that has put me in a hospital. Just minor injuries like a sprained ankle. I do a lot of things to make jumping safer. I open my parachute above the minimum opening altitude. I do not do radical flying under my parachute or in any place, and I watch out for others. I fly defensively.

Are you apprehensive about any aspect of your jump from the edge of space?

No, because I have a good team and they are the ones who are going to get me up and down safely: all of them are professionals. My only concern is ensuring that we have a contingency plan for every possible event that can occur. One thing you do not want at 130,000 feet is having to trouble-shoot a hastily conceived back-up plan.

Barry E. DiGregorio is a research associate of the Cardiff Centre for Astrobiology in Wales