FLUG REVUE January 2004: Europe plans new space shuttles

EADS' PLANS FOR HOPPER

By Matthias Gründer

The satellite transportation market is calling for a substantial reduction in the cost of transporting payloads into orbit. The only way Hopper

of achieving this is to develop and build systems as international, collaborative ventures. Europe does not want to miss the boat, and in the long-term has its sights set on developing its own transport capacity.

The realisation that only reusable space transport systems can transport a wide range of payloads, from unmanned satellites to manned capsules into Earth orbit, at viable cost is as old as spaceflight itself. Over the years there have been several attempts to achieve this objective, but they have all come to nothing. Even the Space Shuttle, the only such project to be fully implemented, has not managed to achieve a cost structure that is anywhere near commercially viable on any of its flights. One of the main reasons why the grandiose objective of full reusability has not been attained has been financial bottlenecks in the development of the ambitious technology. Experience with the Shuttle shows that not even the USA, the most powerful economy in the world, has been able to master this challenging problem.

Today the struggle between opposing social systems is a thing of the past, and co-operation is the order of the day. The International Space Station is a symbol of this new era, but to function smoothly and economically it needs reliable transport systems for astronauts and cargo. At present these requirements are addressed by separate systems – unmanned freight vehicles and manned space taxis which can also be used as rescue vehicles – in order to cope better with failures. The Columbia disaster has shown only too clearly that such a failure can endanger the entire project.

THROW-AWAY LAUNCHERS ON THEIR WAY OUT

Finally the time has come to develop new systems, and Europe has both the capability and desire to be involved. The Edinburgh meeting of ESA's Council at Ministerial Level confirmed that Europe needs its own autonomous access to space. The present platform is Ariane 5, and following certain planned modifications this will be supported in future by the conventional platforms Soyuz and Vega, which are to be launched in Kourou. Programmes aimed at reducing costs significantly are already under way here, but no matter how successful they are, the launch vehicle that is used a single time is on its way out. If Europe is to remain competitive in the medium- and long-term, a successor is needed.

Europe too has had space shuttle projects on the drawing board in the past, but they failed primarily because national interests were placed above those of the Community and because at the end of the day there was never enough money. Now that in EADS Astrium there is finally a unified European space concern, there are also unified ideas regarding a future joint reusable launch vehicle (RLV) to be known as HOPPER.

Meanwhile, past unfortunate experiences have led to some caution, as no one wants to repeat previous mistakes. On the one hand HOPPER is not an official ESA programme – in view of ESA's empty offers, no one could expect otherwise. HOPPER is a project initiated independently and largely funded by industry, albeit with some support from national research resources. On the other hand there is no ambitious schedule offering the assurance that HOPPER will be in routine use before too long. Conservative estimates assume a launch date no earlier than 2020. And finally, the project is concentrating on a purely unmanned system for the transportation of payloads into different orbits.

MANNED SYSTEM REMAINS AN ILLUSION

It is not as if Europe were not capable of building a manned space shuttle, but only in France and Italy is spaceflight viewed as a national mission. Because the other ESA member states have different agendas, there is little prospect of developing and building a manned space shuttle at the present time.

HOPPER will be launched horizontally on a skid sled running along a four kilometre track in Kourou, and carry a payload of up to 7.5 tonnes to an altitude of 130km. Equipped with an apogee engine, the satellite will then climb to its predefined orbit under its own power, while the transporter flies back on a ballistic trajectory to an airfield on an island in the Atlantic that is under European sovereignty. The shuttle will then be taken back to Kourou by ship.

Despite scarce resources, German institutions and companies are also involved on the project. Within the German development programme ASTRA (selected systems and technologies for future space transport system applications), a technology demonstrator called Phoenix has been built with considerable private funding from industry but also with some support from the German government, the state of Bremen and the German Aerospace Research Establishment. Phoenix is currently undergoing intensive testing. The aim of the German companies is to make a significant contribution to the HOPPER project in case this should one day become an official ESA programme. Bearing in mind the financial possibilities and the international apportionment of the work that is on offer, this contribution will concentrate on the RLV landing phase. The flight phases of launch, payload deployment and re-entry will be handled by other partners under the ARES and PRE-X programmes, yet rarely before have they maintained so much secrecy over their plans.

PREVIOUS GROUNDWORK FOR NASA SHUTTLE X-38

Thus, although EADS has published computer graphics of ARES and PRE-X, when one enters those terms in the search engine on EADS' own website, the reply is “no results”.

Why the landing phase exactly? Because considerable groundwork has already been carried out in this area in the form of preliminary research and the manufacture of certain components for the American X-38 research vehicle. Meanwhile Phoenix has already completed its first “flights” in the wind tunnel, in the course of which the aerodynamic low speed flying characteristics were worked out and the forces for all combinations of angle of attack and angle of sideslip were measured.

Integration and technical system testing should be completed by the end of the first quarter of 2004. As well as the wind tunnel tests, the programme will also include towing tests aimed at balancing the hoist sling for the helicopter and ground taxi tests with the flight demonstrator. Once the full functional capability of the system has been demonstrated, the first practical trial, flight testing of the demonstrator, will follow. It would seem that after floundering around on the wrong track in the past, the Europeans are finally on the home stretch as regards developing an independent RLV.

From page 44 of FLUG REVUE 1/2004

Last updated 9 December 2003

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