Flown double-sided Apollo 15 Earth Orbit Chart carried into lunar orbit on the Command Module 'Endeavour,' 16 x 9, signed and flight-certified on the orbital path overlay in black felt tip, "Flown to the Moon on Apollo 15, Dave Scott, Apollo 15 CDR." The chart is marked "Apollo 15, SKB 32100058-201, S/N 1017, 1st Edition, June 1, 1971." The chart, which shows orbital ground tracks over a 1:40,000,000 scale map of Earth, was used to locate the Apollo 15 spacecraft after launch and prior to the Trans Lunar Injection (TLI) maneuver. In fine condition.
Accompanied by a detailed signed letter of provenance from Dave Scott, in part: "I hereby certify that the Apollo 15 'Earth Orbit Chart' is from my personal collection and was flown to the Moon and then in lunar orbit for six days aboard the CM Endeavor during Apollo 15, the first "J" mission extended scientific exploration of the Moon, July 26 - August 7, 1971‰Û_This chart is one section of the series of earth parking orbit charts with orbital ground tracks used to locate the Apollo 15 spacecraft after launch and prior to the Trans Lunar Injection (TLI) maneuver‰Û_This chart was carried aboard the CM Endeavor for the 12-day mission to the Hadley Apennine region of the Moon. The earth orbit period prior to TLI was a critical time to evaluate the spacecraft condition prior to a full commitment to depart Earth and go to the Moon, with no return capability until passing the Moon, a period of over 6 days. The major consideration in the earth parking orbit phase was duration, i.e., the number of earth orbits before TLI, which was defined by spacecraft system considerations. The nominal minimum was set at 1.4 hours with a maximum duration of 4.5 hours from earth orbit insertion to the beginning of TLI. The minimum duration was limited by the time required to perform system checks, both onboard and from the ground, and also to realign the spacecraft's guidance platform. Mission timeline plans indicated that this would require about 1.5 to 2 hours, or approximately 1 to 1.25 orbits. The location of the TLI maneuver was constrained by numerous considerations including the geometry of the moon's orbit and the energy requirements of the lunar transfer trajectory. However, based on other factors, this nominal period could often be extended by other trajectory and spacecraft tradeoffs‰Û_TLI began at 2 hours, 50:02.90 minutes after lift-off and cutoff occurred 5:50.71 minutes later."