Solar sails are spacecraft that may be able to travel great distances at enormous speeds, powered only by pressure from photons emitted by the sun. This informative book explains the history, development, and setbacks of the technology and traces the development of this innovative idea from a Russian teacher's proposal in 1924 to the possibility of space sails powered by artificial light sources. There is even talk of a race of space sails designed by various international teams. Uneven in quality and usefulness, the illustrations include photographs and paintings reproduced in color and in black and white. An entry in the Space and Aviation series.