An ESA-led project with Airbus Defence and Space developed and tested a supercapacitor design able to provide brief bursts of very high power levels to space missions as required. The project designed and constructed a working prototype ‘Bank of Supercapacitors’ based on 34 supercapacitors in series with three strings in parallel, incorporating thermal sensors to keep it from overheating and degrading, and potted for safe operation in the space environment