Time of Entry Interface: 72 hours, 46 minutes GET.Delta-V: 8,016 feet per second (2,443 metres/second).Time of ignition: 37 hours, 44 minutes.Time of Entry Interface: 73 hours, 14 minutes GET.Longitude of splashdown: 165° west in the mid-Pacific Ocean.Delta-V: 5,363 feet per second (1,635 metres/second).Time of ignition: 27 hours, 44 minutes.The data is intended for aborts that would be burned at various times along the translunar coast. Standard form in which crews copy P37 abort PAD data. Additional manoeuvres were required to achieve a parallel reticle pattern near the point of horizon-star superposition.' The ground-supplied angles prevented lunar module structure from occulting the star, but were not accurate in locating the precise substellar point, as evidenced by the fact that the sextant reticle pattern was not parallel to the horizon. This technique was devised because computer solutions are unconstrained about the optics shaft axis therefore, the computer is unable to predict if lunar module structure might block the line of sight to the star. Ground-supplied gimbal angles were used rather than those from the onboard computer. Excess time and fuel were expended during the first period because of difficulty in locating the substellar point of each star. The first determination was begun at a distance of approximately 30,000 miles, while the second, at 24 hours, was designed to accurately determine the optical bias errors.

The first, at 6 hours, was primarily to establish the apparent horizon altitude for optical marks in the computer. From page 4-3 of the Pilots' report of the Apollo 11 Mission Report: 'Two periods of cislunar midcourse navigation, using the command module computer program (P23), were planned and executed.

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