Using the expertise of Germany's ALCATEL SEL, the European Space Agency (ESA) has been developing a GPS Receiver for Space applications. It will be used on board the ESA's low Earth Orbit Spacecraft HERMES, the manned European space shuttle, and the Colombus Free Flier Laboratory. The receiver is a five-channel C/A code and carrier tracking, parallel receiver. A specially qualified version of this unit flew on the German ASTROPAS platform, on board the shuttle STS 59 mission.

The ESA chose ALCATEL SEL in part for their experience in manufacturing GPS systems. The contract was for procuring equipment that would be used for laboratory testing of the GPS Absolute (stand alone) navigation accuracy performance when applied to low Earth orbit vehicles with re-entry capabilities. In addition, the equipment had to be designed for high accuracy GPS applications; relative navigation in support of in-orbit proximity operations and rendezvous, and automatic landing. Finally, the receiver had to be conceived with its future space application and qualification in mind, and a number of special features were introduced for this purpose. Ada was chosen for the receiver in order to ensure reliable and safe software.