The man behind this has a history of producing high quality books at reasonable prices. The X-20 Dyna-Soar was a manned space vehicle that could perform reconnaissance and other functions. It was ready to go, and astronauts had been selected, but it was dropped after a change in the US Administration. This promises to be the definitive book about Dyna-Soar and its variant configurations. It was originally suggested by Walter Dornberger and was an outgrowth of the Sänger orbital skip bomber project.
https://www.kickstarter.com/projects...ef=thanks-copy
Usual disclaimer,
Ed