Each tool was a prototype of a device that "could be used by future satellite servicing missions to refuel spacecraft in orbit. RRM is the first in-space refueling demonstration using a platform and fuel valve representative of most existing satellites, which were never designed for refueling". Competitive approaches Competitive design alternatives to in-space reaction control system (RCS) fuel transfer exist. The ViviSat (Mission Extension Vehicle) illustrates one alternative approach that would connect to the target satellite in a similar way as MDA SIS, via the kick motor, but will not transfer fuel. Rather, ViviSat will use "its own thrusters to supply attitude control for the target". ViviSat believes their approach is simpler and can operate at lower cost than MDA, while having the technical ability to dock with a greater number (90%) of the approximately 450 geostationary satellites in orbit. In September 2012, the Germany DLR Space Administration announced a funded development project to build a two-vehicle set of spacecraft to demonstrate several technologies necessary for on-orbit satellite servicing, including spacecraft refuelling, to enable satellite mission extension and also controlled disposal of a defective satellite. The project is entitled "DEOS" (German orbital servicing mission), and 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 spacecraft will be launched together into low Earth orbit of . , the mission "will be ready for launch in 2018". EADS Astrium Friedrichshafen is the prime contractor for the definition phase of the DEOS project, with a contract value of approximately €13 million. See also Orbital Express — a 2007 U.S. government-sponsored mission to test in-space satellite servicing with two vehicles designed from the start for on-orbit refueling and subsystem replacement. References External links Animation of the on-orbit refueling process An End To Space Trash?, Aviation Week, 21 Mar 2011. Macdonald Dettwiler Gets "Anchor Customer" for Brampton Robotics Plant MDA Signs Intelsat as Anchor Tenant for On-Orbit Servicing Proposed spacecraft Space program of Canada Satellite servicing missions