Electrical sliders in potentiometers for space application

Abstract

From time immemorial mankind asks itself questions regarding the stars and the universe. Since the last century things and people are transported into space. But before this was possible many problems had to be solved. And there are still enough challenges to deal with. One of them is to find out the orientation of the solar array (SA) on a satellite under harsh conditions. A SA consists of multiple solar cells that are connected to produce electric energy for the spacecraft. To move the SA a solar array drive mechanism (SADM) is applied. In order to figure out the orientation of the SA relatively to the satellite an angle sensor can be used and mounted in the SADM. A possible sensor for this application is a potentiometer. Within this thesis it is described how an existing test facility was adapted and another one was built to perform potentiometer tests under space conditions. These conditions are pressures from ambient pressure to high vacuum (1E-6mbar) and temperatures from room temperature up to 300°C.<br />Afterwards two types of rotary potentiometers were tested and the results were discussed. The measuring quantities were load of the potentiometer wiper, friction force, wear, angle and electrical resistance. The two testing bays complied with their function. Both potentiometers showed acceptable behaviour within specified environmental limits. This means they could be tested on a higher test level.