Gemini Operations Handbook, Section 1, GT-5. NASA/MSC, 17 May 1965. Approx. 8 x 10 in. with tab section dividers. Issued to back-up commander Neil Armstrong with information on spacecraft sequential, electrical, environmental, control, navigation, communications, and instrumentation systems. Multiple fold-out diagrams and schematics. Armstrong gave this manual to Gordon Cooper as a memento of the flight. INSCRIBED WITH MISSION TITLES AND SIGNED BY COOPER, CHARLES CONRAD, AND ARMSTRONG, the last on front cover.