Astrium is preparing a new technology mission for the maintenance and disposal of satellites. At the ILA Berlin Air Show, the DLR Space Administration announced that Astrium Friedrichshafen will be the prime contractor for the definition phase of the DEOS (German orbital servicing mission) project.

The order is worth a total of around 13 million euros. The definition phase is the last, decisive step before construction begins on the space vehicles themselves.

The DEOS project will for the first time demonstrate technologies for the controlled in-orbit disposal of a defective satellite. In addition, DEOS will practice how to complete maintenance tasks - refuelling in particular - that extend the service life of satellites.

DEOS consists of two satellites, a 'client' and a 'servicer'. The client acts as the satellite requiring maintenance or disposal.

The servicer carries out the necessary work on the client. The two satellites will be launched together and brought into orbit at a height of 550 kilometres. According to current planning, DEOS will be ready for launch in 2018.

Testing of disposal and maintenance on a client satellite specially launched for this purpose, as opposed to tests on old existing satellites, means that a wide variety of defects can be simulated.

This enables DEOS to demonstrate a complete range of relevant tasks, right up to capturing a satellite that is spinning out of control. Experiments will be performed in an increasing order of difficulty.

The maintenance or disposal of a satellite requires mastering a large number of individual tasks: the servicer has to approach the client without a tracking signal or similar help from the client.

The servicer has to remain at a distance of around one metre from the client for an extended period (>1 orbit) while adjusting its position to avoid collision with the client.

Throughout the orbit, the approach navigation and attitude control must function reliably even when the satellite is in the full glare of the sun or in eclipse.

Before maintenance work can begin, the servicer must establish a firm grip on the client satellite. It must be capable of establishing electrical connections with the client and connecting a vacuum-tight fuel valve.

In order to perform such a wide range of tasks, DEOS will be equipped with a robot arm that can move through seven degrees of freedom.

To a large extent, DEOS is reliant on technologies that have not yet been tested for space operations. In the definition phase, therefore, initial prototypes of the key technologies will be developed, so that subsequent realisation of the project can progress swiftly.

This development work will be carried out by Astrium itself and by specialist companies and research institutions subcontracted by Astrium.

Astrium is carrying out the project at Friedrichshafen and Bremen with a joint team from both locations. It is also being supported by a consortium of subcontractors from the German space industry and space research institutions.

Astrium's Friedrichshafen location has long been the leader in the field of space robotics in Germany. A particular highlight was the ROTEX experiment on the Spacelab D-2 mission in 1993, which was the first time a robot arm in space was controlled in real-time from the ground.

The Bremen location boasts a wealth of experience in the area of approach navigation. For example, the European ATV supply vehicle, with which Europe regularly delivers new supplies to the International Space Station, was designed by Astrium and is built at Bremen site.

The DEOS project will be carried out by DLR Space Administration with funding from the German Federal Ministry of Economics and Technology (BMWi). Sustainable space operations has been a stated objective of the German government's space strategy since autumn 2010.

This made in-orbit maintenance on 'uncooperative' satellites - and even disposing of them when necessary - a topic of major interest at the National Conference on Space Robotics 2012, which was held in Berlin in March 2012 by the DLR with the support of the BMWi.

DEOS allows Germany to continue its long and successful tradition of providing innovative robotics technology for use in space. And DEOS represents the final technological step in developing robotics that can be used in the disposal of dangerous space debris and the cost-effective extension of the service lives of satellites that are already in orbit.