MSSL is responsible for the RGS Digital Electronics (RDE) and the on-board software. The RDE is an essential part of the instrument and performs a variety of on-board high speed processing of the data before these are telemetred down to the ground station. The tasks of the RDE are vital to the performance of the RGS because the instrument collects data far in excess to what can be directly transmitted to the ground, and an on-board intelligent selection has to be made.

The picture below is a photograph of the Engineering-Qualification Model of the RDE, in its thermal finish and showing the ends and connector sockets of the five electronic boards which constitute it.