The X-15, the first fully reusable space-faring aeroplane, was making regular sub-orbital flights in the 1960′s, nearly half a century ago. Had work on the X15 continued, a fully reusable orbital successor could have been in service twenty years ago. Spaceplanes would by now be within sight of the turnaround time, life, and maintenance cost of airliners, and the cost of sending people to space would be one thousand times lower than it is now. Hypersonic and sub-orbital airliners would be on the drawing board or in service. The Shuttle did not achieve these goals because it is not fully reusable.
A truly commercial space industry is now in sight. David Ashford, Managing Director of Bristol Spaceplanes Limited, has been involved with spaceplane design since 1961, and the company has a low-cost, low-risk strategy for spaceplane development intended to catch up rapidly with what might have been.
Bristol Spaceplanes believes that the way to a credible, viable launch vehicle is through progressive development, using tried and tested technology to build real operational experience. A suborbital spaceplane is an order of magnitude simpler to design than an orbital vehicle and can be operated at a profit.
Bristol Spaceplanes has designed an evolutionary development programme of three reusable launch vehicles:
- Ascender is a small sub-orbital spaceplane intended for use as a reusable sounding rocket and for carrying passengers on space experience flights.
- Spacecab is an enlarged and refined Ascender air-launched from a supersonic carrier aeroplane. It uses proven materials and existing engines. It is designed to launch small satellites, transport supplies and crew to space stations, and to pioneer orbital space tourism. Spacecab, to be developed from Ascender, is a candidate to be the first orbital spaceplane, as it has the lowest cost and risk of any contending project.
- Spacebus is and enlarged and mature development of Spacecab, which should have a cost per person to orbit of around $10,000. This could be achieved in about fifteen years.