Solar sail design

Abstract

The romantic notion of solar sailing portrayed in science fiction is of a huge billowing hemispherical film joined to a payload through shroud lines attached at the rim of the sail. Indeed, this picture of solar sailing is described in some early technical publications on the subject. While a hemispherical sail is an obvious initial choice, some thought quickly leads us away from this view — principally, since a hemispherical sail is much less efficient than a flat sail of the same area, and light pressure does not inflate the sail in the same manner as kinetic gas pressure. The pursuit of practical solar sail designs which can be packed, deployed and controlled has led to many varied concepts. The diverse range of solar sail design concepts is somewhat reminiscent of early developments in aviation, when a large number of competing designs were considered. From those initial concepts practical experience led to a limited selection and ultimate evolution towards the standard aircraft configurations seen today, and perhaps the long-term development of solar sailing will follow a similar route. When practical experience of solar sails is at hand it may become apparent that there only a few design concepts that can be truly optimised for certain common classes of mission.