
In 1982, Alan Bond, (who had worked on the Blue Streak rocket and the Daedalus starshp design) began work on air-breathing rocket engines. At around the same time, Robert Parkinson, at British Aerospace, began work on reusable launch vehicles. The next year, Bond patented his engine, known as RB454. The Ministry of Defence classified the design as TOP SECRET. Parkinson and Bond then together created a design for HOTOL (Horizontal Take-Off and Landing ), a revolutionary new space launcher. HOTOL, unlike other rockets, would not take Liquid Oxygen to burn with its fuel. Instead, it extracted oxygen from the air to burn with its fuel. This saved much weight, and allowed HOTOL to be extremely efficient.
HOTOL would have taken off from a normal runway, like an aircraft. A rocket powered "sled" would accelerate it to take-off and then to several times the speed of sound. At this point, the sled would parachute back, and the RB454 would take over, extracting the air's oxygen to burn. Once the air became too thin, a small supply of Liquid Oxygen would be used to place the craft in orbit. Around 7 Tons of cargo could be orbited for a cost of £5 million, far less than for a Space Shuttle launch.
In 1986, HOTOL was officially announced and started up with £2 Million of Government money. Work was carried out at the British Aerospace plants at Warton, Filton and Stevenage. The study ran for two years. In 1989, however, the project was cancelled after the Government refused to put in any further money. This was mainly due to the ideology of the Thatcher Governments of the 1980s: a reduction in public spending meant that there was little chance of funding for a "frivolity" such as HOTOL. In addition, no foreign partners could be introduced due to the TOP SECRET classification of the RB454 engines. Despite this, HOTOL refused to die.
Interim HOTOL
After HOTOL was cancelled in 1989, Robert Parkinson approached the USSR with a new project: Interim HOTOL. This would use a smaller version of HOTOL, with the classified engines replaced by conventional Russian rocket engines. Interim HOTOL would be carried to altitude by the huge Russian Antonov-225 transport aircraft, then released and placed into orbit by its own rockets. The combined weight of the AN-225 and Interim HOTOL would be 250 Tons, and 4.5 Tons could be placed in orbit. As with the original HOTOL design. the project was cancelled in 1992 after both the European Space Agency and the British Government showed no interest. Members of the HOTOL team have now formed their own company, Reaction Engines Ltd, and are working on a new project known as SKYLON, which is in many ways a further development of the HOTOL concept.