Colloquia

Summary

Airbus Defence and Space Netherlands (ADSN) delivers solar arrays for space applications. These solar arrays are stowed together during launch and deploy once in orbit to increase their surface area. This deployment is executed by a number of springs and hinges. Inside of these hinges there are latches which lock the hinge when it is in its final position. This motion of the latch can be monitored by a sensor, at this moment this sensor is a micro switch.

The micro switch comes with a variety of issues and therefore a design implementation study is conducted whether the micro switch can be replaced by a reed switch. Within this thesis three objectives are achieved that together form the design study.

First of all, the physical principles of magnets and reed switches are combined with the results of reed switch behavior tests. From this, a model is created that calculates the activation behavior of a reed switch. This model is sufficiently accurate making it use full
during a stage of a reed switch mechanism.

The second objective focused on the actual design study. Here, the micro switch is successfully replaced by a reed switch and magnet combination. These designs were formed with the help of the previously created model. The designs are 3D printed in order to test functionality.

The last objective verified the survivability and functionality of the reed switch in a space environment. Within this objective thermal cycling, vibration and radiation tests are included since these are all space environment related environments.

In the end, the reed switch implementation in solar array mechanism is auspicious. The model made in this study is incorporated into a graphical user interface where it can predict reed switch activation’s when a magnet passes at a certain trajectory. Furthermore, the redesigns made with reeds show advantages over the original micro switch mechanism as they are more simple, robust and cost-effective. After all the environmental testing the results are
very promising as the reeds show sufficient resistance to these hostile environments and will most likely pass an eventual qualification for space application.