Stepping Closer to Integrated Functional Structures
A recently completed GSTP activity with Space Structures GmbH and Invent, both in Germany, has successfully built a structural panel for satellites that includes embedded functions such as heaters or fuse boxes built in to the laminated composite panel.
Currently, instruments are often developed and tested separately and then bolted on to the panels that make up a satellites structure. More bolts and parts means more weight, less flexibility and more opportunities for something to go wrong.
By integrating the instruments and electronics inside the panel, which can be replaced like-for-like with any standard panel on a satellite, the new type of panels provide opportunities to make a mission less costly and reduce the weight while maintaining the same functionality as one with multiple individual instruments.
The demonstrator panel, was modelled on a system panel from a small GEO satellite, is built out of layers sandwiched together during manufacturing: a carbon fibre outer skin capable of withstanding the extremes of space, a glass fibre laminate containing the electronics and a metallic core that gives the sandwich stiffness and bending strength.
Modelling (done by Space Structures GmbH) and manufacturing (done by Invent) a multi-layered system panel with this amount of complexity had never been done before, so both presented challenges that were solved through multiple iterations. In particular, the manufacturing process had to be optimised as a multi-step process, with the inner glass laminate cured with the embedded features before laying up the outer carbon fibre plies and finally adding the metal core, before curing together as one sandwich panel. The final panel contains: a built-in fuse box; integrated heaters to maintain any temperature-sensitive parts inside the panel; piezo-electric sensors to monitor high frequency vibrations, fibre optics for monitoring the structure for damage; thermistors for measuring temperature; and integrated radiation shielding of the fuse box.
After successful structural and thermal cycling tests, INVENT is now starting a feasibility study with ESA, to assess whether structural panels with integrated radiation shielding can offer a reduced mass solution for heavy equipment in the medical industry, such as MRI scanners.
G617-104MS closed in 2019.