When designing a mission for space, engineers work in terms of ‘end-of-life’ performance – how will a material respond to the extreme environment of space across multiple years? Continuous testing in simulated conditions across the actual timespan required is often not feasible. Instead the team at ESA’s Materials and Electrical Components Laboratory employ established methods to accelerate testing, including the ‘Time Temperature Superposition’ technique – where test materials are subjected to a dynamic thermal-mechanical environment to help estimate how a material will respond over a longer duration. Engineers Virginie Cesar-Auguste and Jason Williamson explain how and why it is applied for testing.