John Young's star chart used during training for the Apollo 11 mission, 6.75 x 16.5, featuring the names of all Apollo navigation stars as well as trace lines that form the constellations used to locate and identify the stars. The chart is designed with the constellations aligned on the ecliptic, with specific stars used for Apollo navigation identified, named, and numbered with a two-digit numerical code ranging from 1 (Alpheratz) to 45 (Fomalhaut). The chart could be used to identify and locate specific stars such that an onboard optical device, the Sextant, could be used to determine the orientation of the spacecraft relative to an onboard Inertial Measurement Unit (IMU); the onboard computer (the Apollo Guidance Computer) would then calculate the location of the craft in inertial space. In very good to fine condition, with a diagonal crease in the lower left corner, and faint silvering to the edges. Accompanied by a certificate of authenticity from Susy Young, wife of the late John Young, certifying that this chart "was used in training for the Apollo 11 mission to the Moon July 16-24, 1969. It has been a part of the John W. Young collection since that time."