The impact of the lunar thermal environment on the design of telescopes for lunar surface operation

The lunar thermal environment poses a unique challenge to the telescope designer as it combines large temperature variations, long hot and cold soak times, and reduced heat rejection capability due to the presence of the lunar surface. The thermal environment for a lunar-based telescope is significantly different than for one operating in Earth orbit. Power and weight requirements and the presence of the lunar surface limit the options available for maintaining the optical components, focal plane array, and subsystem equipment within the required temperature ranges. The effects of the thermal environment may be mitigated in several ways; the use of enclosures or shades; site selection; the use of heaters or phase change materials; and location, orientation, and design of subsystem components. Passive thermal control options are favored to minimize mass, power, and system complexity. Passive thermal control of lunar telescopes is feasible, but may require design compromises or relaxation of some requirements.