PLUGGING IN THE MOON To supply outposts sunk in the lunar night, solar power must come from the south pole

THE EARLY FORAYS to the moon employed throwaway technologies, designed to function during the two-week period of lunar daylight, then to perish in the freeze of the equally long night. But to sustain a colony, everything must be made to survive deathly extremes. During the day, lunar temperatures can reach 120°C at the equator. At night the temperature falls to -220°C, as cold as Pluto. Without a heater, equipment breaks down. Structural components grow brittle and can crack from the mechanical stresses of this huge temperature swing. Without sunlight, solar panels become useless, their broad expanse then serving only to lose heat. Batteries lose capacity, and their liquid components freeze, requiring a power-hungry cycle of using much of the power in batteries just to heat themselves. © 1964-2012 IEEE.