Duration: 18 months
Several manufacturers are developing Solar Power Modules (SPM) for space: flexible sheets covered with thin-film solar cells which are electrically interconnected and encapsulated to protect the cells against radiation etc. These SPMs are flexible by nature much more robust than conventional solar cell assemblies. These features enable novel solar panel designs compared to the traditional carbon-fibre composite sandwich panels. The present groundbreaking idea aims to replace rigid panels by stiff and lightweight frames in which the flexible SPMs are suspended, since the stiff and flat support of sandwich panels is no longer needed.
Flexible solar arrays are available on the market for high-power applications only. A flexible blanket is usually lightweight but the solar cells on the blanket require a rigid support, protective foam layers etc. to survive the launch. These support structures and the complex deployment mechanisms contribute significantly to the mass and stowed envelope. Therefore, flexible solar arrays have not been attractive for smaller, low-power spacecraft so far.
The emerging SPM technologies are much less vulnerable than conventional solar cells. This opens up the opportunity to design a flexible solar array for LEO applications and constellations using the much simpler architecture of a rigid solar array, albeit with flexible SPMs in frames instead of rigid panels.
In this disruptive concept, the SPMs can vibrate freely during launch. Nevertheless, the maximum displacement under dynamic launch loads can be tuned and damage can be avoided by choosing the proper way to attach the SPMs in the frame.
This flexible solar array concept is optimised for LEO spacecraft, in particular for the constellation market. The stowed wing fits to existing spacecraft platforms and offers a significant mass reduction, allowing more spacecraft in a single launch. The mass and cost savings enable the use of low-cost, less-efficient solar cells like silicon in the SPMs.
