FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1986
1986 - 0486.PDF
Hotol: where next? In January 1985 the European Space Agency council of ministers agreed on the future direction of the European launcher industry. It approved further development of the French-sponsored Ariane system of multistage expendable rockets to provide what it hoped would be a reliable, cost-effective satellite launch capability. To the casual observer this might have appeared a sensible way to continue the development of a system that has, on the whole, proved successful. It would lead, in the early 1990s, to Ariane 5, able to carry Shuttle-sized payloads into low Earth orbit. There would also be a facility for manned launches in the Hermes space- plane, which is designed for attachment to Ariane 5, replacing the satellite payload section. British Aerospace disagrees with this philosophy. As Europe's prime satellite builder it wants a launch vehicle that is optimised to launch popular sizes of satellite at the lowest possible cost. In late 1982 the company therefore began studies of its own, setting itself a target launch cost one-fifth that of the Shuttle. Largely as a result of a new engine proposed by Rolls-Royce, it came up with Hotol, an unmanned, fully reuseable single-stage- to-orbit spaceplane. Hotol has just received £3 million- proof-of-concept funding from the British National Space Centre. The programme will establish whether the concept is work able, and in particular whether the Swal low engine proposed by Rolls-Royce can provide single-stage-to-orbit capability. Britain, as an ESA member, naturally wants to "Europeanise" Hotol, both because around £4,000 million funding is needed for full-scale development, and because it genuinely believes that the vehicle would be a major asset to Euro pean launch capability. The difficulty is Britain recently approved proof - of-concept funding for its Hotol single-stage-to-orbit satellite launcher. BAe is now selling the Hotol idea to Europe—but the USA is also interested. Julian Moxon reports. Hotol could begin flight trials in 1996 if devel opment funding materialises. The two rear fins have now been deleted that Hotol has come along about three years too late to be included in ESA's long-term plans. The pressure is on, for strong interest in Hotol, and particularly in its engine, has been expressed in the USA. The Air Force would dearly like to get its hands on the Swallow design since it offers a possible solution to the problems of power for the Aerospaceplane, the hypersonic vehicle project recently awarded $600 million for validation studies (80 per cent of which is being spent by the military). The dilemma facing Britain is that the offer of US money will not last for ever, since US research into air-breathing rocket engines will eventually bear fruit and enable it to go ahead on its own. Shar ing the design with the USA would also effectively cut Britain out of involvement in future European launchers although, if Hotol is built and lives up to expectations, it will clearly be a powerful competitor to other launch systems. A further twist in the affair emerged on February 10, when it was revealed that ESA had issued two requests for proposals, each worth 225.000AU (accounting units, or around £140,000), for studies of advanced airbreathing engines. This is the kind of engine Rolls- Royce is developing for Hotol, so it would appear that ESA is at last showing posi tive interest in the British launcher. Peter Conchie, BAe's head of future business, is adamant that Hotol should, if possible, become part of the European framework. The British National Space Centre, headed by Colin Gibson, has made several presentations to ESA, although these have suffered from the fact that the Swallow design is classified, and has yet to be proved workable. Conchie offers no solution as to how Hotol should be incor porated into ESA's long-term plans, but he says he has "every hope" that one can be found. Interestingly, he says that Europeanisation would probably mean that France, as Europe's principal supplier of launchers, would get the lion's share of work on Hotol, although key technologies would be retained. The entire Hotol question hinges on whether BAe and Rolls-Royce can estab lish the vehicle's credibility before final decisions are made on Ariane 5 and Hermes. The proof-of-concept pro gramme lasts two years, but Conchie says that a "significant release of information" will have to be made before the end of this year if ESA's appetite is to be sufficiently whetted. Initial POC work will therefore concentrate on validating the critical technologies. Most critical of all is the Swallow engine, the key to Hotol's performance. Rolls-Royce technical director Gordon Lewis says that the engine "needs further definition", but is a "very valid physical concept". Lewis tells Flight that studies so far indicate that Swallow is 80 per cent likely to work as predicted. Swallow is an integrated dual-role powerplant enabling air-breathing pro pulsion through the atmosphere and rocket propulsion as the air becomes 38 FLIGHT INTERNATIONAL, 1 March 1986
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
