Solar arrays are the main source of energy of PW-Sat2. There are many different ways to attach panels to the structure of the satellite – they can be attached directly to the walls or even, as in the case of our first satellite (PW-Sat), mounted on a deployable tail (requiring flexible cells).
However, in the case of PW-Sat2, we decided to use a solution, that involves the use of retractable solar arrays as well as cells fixed to the main structure. Due to this, we can increase the surface area covered with cells and as a result we are able to collect a larger amount of energy.
As we decided to use deployable solar panels, we stand in front of a challenging task to design an unfolding system. Such a system must be as simple as possible because the less parts it has, the higher the probability of success is. The panels should not open up too quickly, as this can damage the walls of the cells or cause vibrations resulting in serious damage to the satellite. It must also be designed in such a manner that the procedure of opening the deployable arrays ends up putting the panels in the desired position.
The system design is also complicated due to the structural conditions and requirements accorded to building a satellite to CubeSat standards. During the design process we must also take into account issues related to friction and metal degassing in a vacuum.