Ascender  

Ascender Artist's Concept [Enlarge]. For more Ascender images visit the Gallery.

The Ascender Spaceplane

Ascender is designed to:

• Win the X-Prize
• Carry passengers on space experience flights
• Spearhead low-cost access to space

Ascender is designed to be the first sub-orbital aeroplane since the X-15, and the first ever to carry passengers to space. It would start a sub-orbital space tourism business that would build up the credibility needed for full orbital tourism. It is based on a design included in a feasibility study for the European Space Agency. Four leading British aerospace companies took part in this study, Dowty Aerospace Limited, Dunlop Aerospace Limited, Pilkington Aerospace Limited and Ricardo Aerospace Limited. The UK Minister for Space commissioned an independent review of this study that "did not identify any fundamental flaws" in the concept.

Ascender uses proven materials and existing engines. It takes off from an ordinary airfield using its turbofan engine and climbs at subsonic speed to a height of 8 km. The pilot then starts the rocket engine and pulls up into a steep climb. When the rocket fuel is used up Ascender is climbing close to the vertical at a speed of Mach 2.8, from which it coasts to a maximum height of 100 km. Ascender then enters a steep dive. On reaching the atmosphere the pilot pulls out of the dive and flies back to the airfield from which he took off 30 minutes previously.

Stage Altitude km Mach No 1 8 0.6 2 64 2.8 3 100 0 4 46 3.3 5 24 3.3

Ascender will carry a crew of two and two passengers (or other payload) to space and back. Passengers will experience two minutes of weightlessness, will see superb views of Earth, and will see the sky turn black even in daytime.

Ascender uses proven materials and existing engines. The only innovation is in the concept, which is in essence that of a light aeroplane of hypersonic shape fitted with a rocket motor.

Ascender would be the first aeroplane capable of taking off under its own power and of making several flights to space per day. (The X-15 of nearly forty years ago had a somewhat higher performance, but had to be launched from a B-52 converted bomber and needed several weeks of servicing between flights.)

Ascender could be flying in three years as a research aeroplane, and carrying passengers on space experience flights within seven years. Work at present is being funded privately. Discussions are taking place with potential strategic partners. Ascender has EUREKA status as a suggested project.

Ascender is offered for a variety of research purposes, for astronaut training, and for passenger space experience flights.

Feasibility

Ascender is well within the aeronautical state of the art. The aerodynamics, structure, engines and systems are all based on those of existing aeroplanes or launchers. The originality is the way the total concept has been put together so that conventional technology leads to a unique capability.

Ascender Specifications

Cost and Programme

The development programme calls for Ascender to fly within three years of full go-ahead. The cost to early operational use is comparable to that of just one fighter aeroplane off the production line. This remarkably low cost is made possible by the design concept and by excluding any component not essential for the basic mission.

After a few years in sevice, the cost per flight of Ascender would be reduced to a level comparable to that of a jet fighter, i.e. a few £ thousand. Then routine everyday flights to space (albeit brief) would become possible at a cost affordable by middle income people prepared to save.

Successors

Ascender would lead naturally to a fully orbital spaceplane. That proposed by Bristol Spaceplanes Limited, Spacecab, uses existing engines and proven materials and would be ideal for launching small satellites, for ferrying crews to and from space stations, and for pioneering orbital space tourism.

The cost of developing Spacecab is equivalent to about three Shuttle flights. The cost per flight will be well over 100 times less than that of the Shuttle, such are the benefits of full reusability. (The Shuttle is only partly reusable. It is like a car whose fuel tank has to be renewed and engine stripped down and refurbished after every journey.) Thus Spacecab would pay for its own development very soon, by greatly reducing the cost of space missions.

An enlarged development of Spacecab, called Spacebus, is designed to carry 50 people to and from orbit. The cost of a few days in a space hotel would come down to less than £10,000 using Spacebus, when rocket motors and other systems have reached airliner standards of long life and low maintenance cost. This is likely to lead to a large space tourism industry, which will probably become the largest commercial use of space.

Space tourism is probably the only market for spaceplanes large enough to provide the funding for the continuous development towards the £10,000 cost target, which could be achieved within about fifteen years. Thus really low cost space transportation depends on the development of a space tourism industry.

A second generation Spacebus would be capable of carrying passengers from Europe to Australia in some 75 minutes flying time.

Mind-Set

If these claims seem far-fetched, it is worth remembering that Spacecab is based on European Aerospace Transporter designs considered feasible more than thirty years ago. The X-15, with a performance somewhat higher than that of Ascender, made 199 flights between 1959 and 1968. It was a very advanced aeroplane for its day, but developments since then mean that comparable performance can be achieved on an "everyday" basis.

A fully reusable orbital spaceplane could have been developed in the early 1970s, as a follow-on to the X-15. The original design for the Space Shuttle, which was started in the early 1970s, was fully reusable. Had this been developed it is highly probable that a second or third generation version would be carrying tourists to space today. Due to budgetary pressures this fully reusable design was abandoned in favour of the present semi-reusable Shuttle. This design is as expensive to fly, or even more expensive, than expendable designs of comparable payload. As a result the impression has persisted that space transportation must be expensive and risky.

Benefits

The main benefits of low-cost space transportation are:

1. In the short term :- Jobs
2. In the medium term:- Better and less expensive space science (including Earth Observation, which is a key asset for understanding our environment.
3. In the longer term:- Recharged vision batteries for the human race. Astronauts, nearly four hundred to date, have tended to come down with greener and longer term perspectives than when they went up. When millions of people fly to orbit each year, the way we look at our planet could well be transformed.

Thus Ascender should trigger a revolution in space travel. The cost of Ascender is easily affordable by the UK, and we have the required technology. Follow-on developments would be ideal for international collaboration. There is therefore an opportunity for the UK to take the lead in a new golden age of space on a shoestring budget.