The technical heart of our continent’s space activities needs a lot of power to keep it going. More than four kilometres of heavy duty 10 kilovolt cables like this one run beneath ESA’s ESTEC establishment in the Netherlands.

Each underground cable contains three wires and a screen, sufficient to supply the energy demand for several ESTEC buildings. Set up in a ring configuration for added robustness, the cables are linked to more than twenty-eight 10kV power stations, multiple transformers and gear switches, used to distribute electrical power over the site and to change the voltage level as needed.

ESTEC’s Test Centre for satellites, suite of technical laboratories and ventilation systems and so on have very different current, voltage and stability requirements than its ordinary offices and meeting rooms.

This image is one of the 99 Objects of ESA ESTEC, an ongoing collection of intriguing, often surprising artefacts helping tell the story of more than half a century of activity at ESA’s technical heart.