Low-Power, Zero-Vibration Sorption Coolers

A report discusses three designs of proposed low-power, zero-vibration coolers for infrared instruments planned to be flown aboard spacecraft to perform astrophysical observations far from Earth. The designs take advantage of the radiative precooling available in the projected deep-space operational environments: such precooling makes it possible to reach radiator temperatures as low as tens of kelvins. The working fluids would be helium and hydrogen, and vibration would be eliminated by the choice of thermally cycled gas-sorption (hydrogen/metal hydride and helium/charcoal) units instead of mechanical compressors.