NASA missions, from earth orbit CubeSats to deep space, require thermal management. For this a switchable emissivity surface is desired, but the only established solution, mechanical louvers, is heavy and clumsy. In Phase I, Triton Systems working with materials scientists at a leading research university demonstrated an innovative film which switches from low to high emissivity above a set threshold temperature. Feasibility experiments showed the film self-switched from a low emissivity 0.08 to a high peak emissivity 0.97 above a critical temperature which can be engineered in the range 10-70C as required for a specific application. The film has no moving parts, is composed of all solid state, stable materials, can be deposited on flexible polyimide substrates, requires no external power or control, and shows no sign of deterioration or fatigue over millions of temperature change cycles. nmental tests will be carried out.