Rotary radiators for reduced space powerplant temperatures

If new radiator concepts can achieve radiator weights below 3 kg/sq m, nuclear space powerplants can operate at temperatures below 900 K and use stainless steel construction. Tube-and-fin or heat-pipe radiators weigh at least 5 kg/sq m because the tube walls must be thick enough to prevent or limit meteoroid punctures. However, radiators that require no meteoroid protection can be built using low-vapor-pressure liquids that can be exposed directly to space. One possible design for such a radiator is the 'rotary radiator' that uses centrifugal force to move the liquid across a thin radiating disk and uses surface tension to retain the liquid despite meteoroid punctures.