1956. First edition thus. 184 pages. Pictorial dust jacket over green cloth. Black and white photographs and diagrams. Colour illustration plates by Chesley Bonestell. Pages with some foxing and tanning, particularly to endpapers and textblock edges. Binding remains firm. Boards have mild shelf wear with light rubbing and corner bumping. Some mild marking and tanning. Clipped jacket has heavy wear with tears, chipping and creasing. Some rubbing and marking to surfaces.