COSA - Core Solar Array Drive Electronics
Satellites are usually powered by solar energy which is collected by solar panels. In most cases these solar panels are directed towards the Sun using solar array drive mechanisms (SADMs). The motors of these mechanisms are controlled by solar array drive electronics (SADEs).
One problem when supplying SADMs to different customers is that the power and control electronics interfaces between the motors and the satellite platforms vary a lot from satellite to satellite. In order to overcome this problem the COSA study set out to define a very simple and inexpensive "Core SADE" (see picture "Schematics of COSA").
This small electronics box converts output signals of the on-board computer to motor drive voltages in their simplest form. Usually this method is sufficient for telecom satellites. The Core SADE can be configured to cover different satellite bus voltages and different motor types.
The COSA project involved the development of a new type of voltage control for the Core SADE which allows for economical operation/dimensioning of the electronics (or the motor), even in the case of extreme variations in motor temperatures (from -80° up to +130°).
RUAG Space GmbH - Gerhard Osterseher