1 - 17 3. Guidance and Navigation a. During lunar orbit, the CSM and LM will utilize the same landing site REFSMMAT such that the gimbal angles would be 0,0,0 at landing with the LM sitting face forward on landing site number two and the CSM over the landing site pitched up 90° from local horizontal „heads up“. b. During PTC the CSM/LM x-axis is pitched up 90° (North) for TLC and down 90° (South) for TEC with the Y-Z axes in the plane of the ecliptic. This change in x-axis pointing is to enable simultaneous viewing of the earth and moon through the side windows while maintaining a favorable high gain antenna position. c. The CSM tracking light will be on continuously from undocking to landing and from LM lift-off to docking. 4. Landmark Tracking The following ground rules were used for landmark tracking. a. IMU to be realigned on the dark side preceding each tracking period. b. MSFN is reacquired after each tracking period. The tracking data will be acquired by MSFN after all the marks have been made and while N49 (∆R,∆V) is displayed. MSFN will give a GO when data acquisition has been verified. c. The pseudo landmark tracking (A1) will be used to determine the altitude of an area in which the LM will be making altitude checks after DOI. The data will be processed during the sleep period after the trackings and relayed to the LM prior to undocking. d. In the docked configuration the CSM/LM approaches the landmark in an inertial hold attitude. This inertial attitude places the spacecraft 2° below the local horizontal at the 35° elevation angle point. At 35° elevation angle a pitch down of O.3°/sec is initiated. Five marks are then taken with the time between marks a minimum of 25 seconds. (See tracking profile) e. In the undocked configuration the CSM approaches the landmark in ORB RATE and pitched down 22° from the local horizon- tal. At 35° elevation angle five marks are taken with the time between marks a minimum of 25 seconds. ORB RATE is continued throughout the marking period. f. In the undocked COAS tracking the CSM will approach the LM in ORB RATE heads up and pitched down 40° from the local horizontal. When the LM is centered in the COAS the CSM will initiate a 40° variable pitch rate to keep the LM centered in the COAS. 2° 35° 35° 22° 40°