As more commercial companies enter the space business, and it becomes ever more competitive, efforts are being made to cut the costs involved. Examples range from SpaceX’s ongoing efforts to bring a Falcon 9 rocket booster back to a vertical landing, and Blue Origin's plans to do the same with their boosters, to the UK’s revolutionary Skylon concept of a spacecraft that takes off and lands on a runway. Now one of the world’s leading conventional space companies, Europe’s Airbus Defence and Space, has revealed that it has been quietly working on its own plans to reduce the expense of accessing orbit by reusing parts of the launch vehicle. Airbus Defence and Space, which is the second largest space business worldwide, is developing a concept called Adeline (ADvanced Expendable Launcher with INnovative engine Economy) that will allow the most costly elements of a rocket to be reused—namely the propulsion system and avionics, which make up between 70 and 80 per cent of its total value. Rather than attempt to return a complete launcher for recycling, Airbus intends to build a special return module that can potentially be fitted to the base of any rocket launcher, though it particulary has in mind the next generation Ariane 6 rocket that is currently being developed by the European Space Agency (ESA).
An impression of the Adeline module returning to land on a runway after launch. Image credit: Airbus Defence and Space
Following launch, and separation from the rocket’s upper stages, the Adeline module would perform an atmospheric re-entry, with the launcher’s propulsion system and avionics protected by a heat shield that Airbus has already gained expertise in building for missions including Mars Express and the Huygens probe which landed on Saturn’s biggest moon Titan.
Unlike SpaceX’s vertical landing solution, Adeline is intended to be brought back to Earth using aeronautical propulsion following re-entry. It will fly like an Unmanned Aerial Vehicle (UAV), thanks to its winglets and deployable propellors, to a landing on an ordinary runway, just like any other aircraft.
Airbus Defence and Space—previously known as EADS Astrium—have been testing the Adeline concept since 2010, first with simulations and then with scaled down demonstrators. The studies are aimed at validating the technical aspects of the concept before a maiden flight of a full module is made in 2025.
The company says their system represents one of the most important ways to reduce the cost of a launch, and estimates that it will allow savings of up to 30 per cent to be made.
A diagram showing how Adeline might return expensive components to Earth. Image credit: Airbus Defence and Space
Airbus Defence and Space is also studying other solutions to reuse rocket parts, including space tugs that could stay in orbit ready to shift satellites to their required positions. At present, a satellite is put into space by a launcher made up of several stages, with an upper stage that carries it to its orbit before falling back into the atmosphere to burn up.
Under the electric space tug concept, the upper stage will be left in a parking orbit. The next launcher will refuel it with liquid propellant and give it a satellite to place into its own required orbit—possibly a communications satellite that needs to go into a high geostationary orbit. Once the space tug has done this, it will return to its parking orbit to await its next mission.
Airbus Defence and Space say the space tug concept will allow smaller, less costly launchers to be used, plus less fuel. The tugs will also be able to upgrade, repair, resupply or reposition satellites. And when its service life is over, it could be sent on a remote exploration mission or burned up in the atmosphere.
A demonstrator being flown to test the concept behind Adeline. Image credit: Airbus Defence and Space