This wafer of Gallium Nitride – a material more typically found at the heart of Blu-Ray players – has been etched with hundreds of space-quality microwave integrated circuits. Many of ESA’s most ambitious future missions for telecommunications and Earth observation have only become possible because of a switch to this high-power and high-temperature capable semiconductor – regarded as the most promising material since silicon.

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