SERVICE PROPULSION SYSTEM SERVICE PROPULSION SYSTEM (SPS). – The budget presented in table 5-4 is for a July 16 launch, 72 degree launch azimuth, fi rst opportunity injection, 59.5 hour lunar parking orbit, and fast earth return. The assumptions used in preparing this budget are presented in table 5-5. ∆V requirements were coordinated with LMAB in MPAD. It should be noted that the mission fl exibility allowance of 900 fps has been used in addition to the fast return. In real time however, it is highly likely that a slower earth return would be performed in the mission fl exibiblity ∆V had already been used (e.g., for LM rescue). Table 5-4 shows 3906 lbs of propellant remaining nominally and a total propellant margin (accounting both for the fl exibility ∆V and the fast return) of 1268 lb. Table 5-4 – APOLLO 11 SPS PROPELLANT SUMMARY PROPELLANT PROPELLANT ITEM REQUIRED, LB REMAINING, LB Loaded a -- 40803.0 Trapped and unavailable 441.4 40361.6 Outage 59.5 40302.1 Unbalance meter 100.0 40202.1 Available for ∆V -- 40202.1 Required for ∆V TLMC (120 fps)b 1166.4 39035.7 LOI-1 (2924 fps, 5 min. 59 sec.) 23862.4 15173.3 LOI-2 (157.8 fps, 16.4 sec.) 1115.4 14057.9 LOPC (16.6 fps, .9 sec.) 73.8 13984.1 TEI (3292.7 fps, 149 sec.) 10077.8 3906.3 Nominal remaining -- 3906.3 Mission fl exibility (900 fps) 2212.4 1693.9 Dispersions (-3 σ) 426.0 1267.9 Propellant margin -- 1267.9 a 15712.0 lb of fuel and 25091.0 lb of oxidizer this is loaded on CSM-107. b Includes 19.7 fps for evasive maneuver. 5 - 20