Future prospects in space transport through reusable launch systems
Paris, 14 June 2003
Sagging commercial satellite markets and distorted competitive conditions in the launch service and launch systems sectors clearly show that conventional, single-use launch vehicles need to be adjusted to meet the market's demand for improved profitability, efficiency and versatility in the medium term. Studies prove that Europe's position in the global market and sustained, autonomous European access to space can only be ensured by drastically lowering current transportation costs. This, however, can only be achieved by using reusable launch systems.
HOPPER: Europe's autonomous transport vehicle
In its HOPPER concept, EADS SPACE Transportation has gone for an autonomous transport system that is noted for its high degree of reusability and considerably lower mission costs. The unmanned HOPPER will be launched horizontally on a skid sled running on a four kilometre long track. With a length of more than 50 metres and a wing span of more than 27 metres, the vehicle itself is quite compact. The re-entry angle will be optimised so as to keep the frictional heat at the outer skin substantially lower than that of the Space Shuttle, for instance. This will allow the sensitive and expensive thermal protection shield to be replaced by an affordable, low-maintenance heat protection system. Due to these features, Hopper is intended to transport payloads to orbit at 75% lower cost than conventional transport systems.
HOPPER can carry payloads of up to 7.5 tons and will deploy them – as a rule a satellite on an upper stage booster– from its tail at an altitude of 130 kilometres and then automatically return to Earth while the payload proceeds independently to its destination in geostationary or low-earth orbit, such as the ISS for instance. HOPPER will be launched from the European Space Centre in Kourou, French Guiana, and, after a flight across the Atlantic Ocean, will land on European territory (e.g. islands in the Atlantic). In comparison to the Shuttle, which orbits the Earth several times before re-entry, HOPPER is indeed a more efficient system. HOPPER can be transported back by ship. Should the ESA decide in favour of the HOPPER concept the space vehicle will be ready for use by the year 2020.
PHOENIX: efficient development at national level
In order to be able to reduce costs, a flight demonstrator, a 1:7 scale model of the future HOPPER vehicle, is being built first. Since February 2000, EADS SPACE Transportation has been developing and building the PHOENIX technology demonstrator, which will serve as prototype of the reusable space transport system HOPPER. Within the German development programme ASTRA (selected systems and technologies for future space transport system applications), Deutsches Zentrum für Luft- und Raumfahrt (DLR) appointed EADS SPACE Transportation, among others, prime contractor for the technology demonstrator PHOENIX. This flight demonstrator made in Bremen is indispensable for first flight testing. Engineers will be provided with information, which cannot be achieved by means of wind tunnel tests or computer simulations. This procedure will also allow to optimise the system as quickly as possible and thus reduce development time considerably.
With a span of 3.90 metres, wing and control surfaces of the PHOENIX flight demonstrator, an aluminium structure having a weight of about 1,000 kg, were kept as small as possible to minimise drag during automatic touchdown. During the test flights, the PHOENIX fuselage will be used to accommodate avionics, navigation, data transfer and energy supply systems.
Integration and technological system testing are scheduled for completion by the end of the first quarter of 2004. Testing will comprise, among others, wind tunnel tests, towing tests to adjust the hoist sling by using a PHOENIX mock-up, as well as taxi tests with the flight demonstrator: Once total functionality of the system has been confirmed, first practical trials, namely the flight testing of the demonstrator will be undertaken in the course of the year 2004. The first flight test will take place in Visdel in Northern Sweden early in summer 2004. The test area, the North European Aerospace Testrange (NEAT), features a runway with a length of 2.3 kilometres and a width of 45 metres. A special heavy-duty helicopter tows the PHOENIX to an altitude of 2,400 metres and then releases it. Onboard sensors integrated into the cargo bay, a GPS-based navigation system as well as the telemetry and telecommand system control, monitor and record the mission. Testing particularly focuses on general flight characteristics during free fall, steep landing approach and subsequent automatic touchdown.
EADS SPACE Transportation has already invested € 7,5 million out of own funds into the PHOENIX project, in which the state of Bremen is also financially involved with an amount of five million euros. Partner companies, DLR and the Federal Ministry for Education and Research are also contributing to the 16 million euros required for the project.
PHOENIX development was preceded by a study with which the European Space Agency ESA commissioned EADS SPACE Transportation within the Future European Space Transportation Investigation Programme, FESTIP, in 1994. Investigation aimed at defining the most cost-effective and most efficient concept of a reusable space transport system. In 1998 a definite decision was made: The HOPPER concept met all requirements. Development of the system was envisaged in order to be able to offer favourable European launch services in the long run. Within the framework of the German ASTRA programme, DLR and EADS SPACE Transportation as prime contractor started with the realisation of the project.
ASTRA: Development basis for future transport systems
ASTRA is the German contribution to the European development of reusable transport systems and goes thus beyond the PHOENIX project. Co-ordinated by DLR and funded to the tune of 40 million euros, the ASTRA programme is intended to gain the necessary system competence for autonomous access to space. Programme activities cover a wide spectrum, from ground facilities to payload delivery mechanisms and the creation of maintenance instructions for the transport system. In addition to EADS SPACE Transportation and DLR, companies such as MAN-Technologie, OHB-System and Kayser-Threde, the Centre for Applied Space Technology and Microgravity (ZARM) at the University of Bremen as well as three special research departments of the German Society for the Advancement of Scientific Research (DFG) at the Technical Universities of Aachen, Munich and Stuttgart are involved in the programme.
Paris/ Le Bourget, June 2003
EADS SPACE Germany
Dr. Mathias Spude
Phone: +49-421-5 39 5710
Fax: +49-421-5 39 45 34
EADS SPACE Transportation
Phone: +49-421-5 39 53 29
Fax: +49-421-5 39 45 34
Phone: +33-5 56 57 37 16
Fax: +33-5 56 57 30 19
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