1 - 15 2. DSE Operation a. The DSE will normally be operated via ground command except for special cases where the operation is time limited. In these cases the crew may be asked to rewind the tape. b. During the earth orbit period when the CSM is not over a MSFN station, CSM TLM-LBR data will be recorded on the DSE and will be dumped during the pass over the US and over CRO prior to TLI if possible. c. DSE will be used for CSM HBR and voice recording during all CSM engine burns. d. DSE data and voice recordings will be made in CSM LBR mode whenver possible in order to minimize the DSE dump time. e. During PTC using the HGA REACQ communications mode the DSE will be used to record LBR data when the HGA is not in the MSFN field of view. f. During lunar orbit LM operations, the DSE will be used to record LM-TLM-LBR data during all docked LM activites that occur on the lunar farside. For undocked LM activites only DOI will be recorded as VHF ranging is required. g. DSE will be used to record all HBR entry data during the blackout region. 3. Launch - Earth Orbit Phase a. OMNI B and VHF LEFT will be selected for lift off. OMNI D will be selected by the crew during boost phase if the launch azimuth is less than 96° or OMNI C if the launch azimuth is greater than 96°. OMNI D will probably be the best antenna for earth orbit. b. VHF Duplex B will be used for launch, and Simplex A for earth orbit operations. c. VHF Simplex A will be used for entry to be compatible with recovery forces communications. 4. Translunar and Transearth Coast Phase The translunar and transearth sleep communications mode will be as follows. The CSM x-axis will be placed normal to the ecliptic plane. The CSM will be rolled at a rate of approximately three revolution per hour. During the near earth sleep periods prior to 30 hours GET (range less than 120Knm) omni antennas B and D will be used. During the other sleep periods (beyond 120Knm) the high gain antenna may be required (in the REACQ mode). The REACQ configuration will provide approximately 210 degrees of HGA coverage per CSM/LM revolution or 35 minutes of MSFN coverage per hour. The REACQ configuration will also allow MCC-H to use real time control to select TLM HBR or LBR and to dump the DSE during each spacecraft revolution. 5. Lunar Exploration Phase a. Normal CSM communications between MSFN/LM will be by S-Band during the lunar exploration period. b. If additional communications capability is required the S-Band erectable antenna will be deployed by the EVA crewman and will be utilized for all LM/MSFN/CSM communications. c. During periods when both crewmen are EVA, the „AR“ position (Relay Mode) will be the normal communication mode on each of the Extravehicular Communication System (EVCS). The CDR will relay the LMP VHF voice and data to the LM which in turn will relay to MCC-H via S-Band. E. CSM Notes 1. Electrical Power System and Water Management a. Spacecraft lift-off switch positions are listed in the Apollo Operations Handbook (Volume 2) for CSM 107. b. The CSM will remain fully powered up throughout the mission (CMC, IMU and SCS in the „operate“ configuration and optics power-up as required). c. Fuel cell H2 and O2 purging is scheduled as follows H2 approx- imately every 48 hours and O2 approximately every 12 hours.