NASA SP-413, “Space Settlements, A Design Study,” was published in 1977 and brought together the results of a 1975 NASA-Ames Research Center effort to do a preliminary study of a giant torus space station for several thousand permanent inhabitants. It is a basic text on the subject of space colonies, but obtaining a copy of the printed book of course requires money (but not much… a quick check at abebooks.com shows them going for about $8) and online versions have typically been either black-and-white scan PDFs of indifferent quality, or versions rendered into painful HTML format. Fortunately, someone (it’s unclear to me who, though it seems a professional job) has scanned in the book and all the illustrations and reformatted the text into an all-new, clean PDF version.
The PDF can be downloaded HERE.
Much more aerospace stuff is available via the APR Patreon.
