The characteristics of retroreflectors that include curved mirror surfaces are theoretically investigated. The use of curved mirror surfaces in a cube-corner retroreflector is an effective method for diverging the reflected beam, especially in a large-aperture hollow retroreflector. The effect of curved surfaces is demonstrated for simple examples that give circular and elliptical wave-front patterns. The method was applied in the optical design of a satellite retroreflector in space, which is to be loaded on the Japanese polar orbit Advanced Earth Observing Satellite.