◆ SpookStack

Table 38. Flight-Phase Definitions Flight Phase 0 Description SRM auxiliary thrust phase 1 First-stage thrust phase if no auxiliary SRM's carried, or First-stage thrust phase after SRM separation 1.5 Attitude-control phase after first-stage thrust phase or between first and second-thrust phases 2 2.5 Second-stage thrust phase Attitude-control phase after second thrust phase or between second and third-thrust phases 3 Third-stage thrust phase, or third thrust phase if second stage is restartable 3.5 Attitude-control phase after third thrust phase or between third and fourth thrust phases 4 Fourth thrust phase, or Upper stage/payload thrust phase 5 Attitude control phase after Flismt Phase 4, or orbital phase In some cases, two•flight phases are listed opposite an entry, e.g., 2 and 5. This means that some failure or anomalous behavior occurred during the second-stage thrusting period that did not prevent the attainment of an orbit, but did result in an abnormal final orbit. Other somewhat arbitrary decisions were necessary in assigning a flight phase when an expended stage failed to separate, or an upper stage failed to ignite. If, for example, the first and second stages failed to separate, any of flight phase 1, 1.5, or 2 could be assigned, depending on the exact cause of the failure. The detailed information needed to make the proper choice was sometimes lacking. Table 39 is provided to assist in understanding how flight phases were assigned for Atlas, Delta/Thor, and Titan vehicles. Table 39. Flight Phases by Launch Vehicle ·Flight Phase Atlas Deltall'hor Titan 0 Castor burn Castor /GEM burn SRMsolo 1 1.5 2 Atlas booster Booster separation Sustainer First-stage bum Vernier solo - Sep 1/2 Second-stage bum Stage 1 Stage-1 separation Stage 2 2.5 Vernier/ACS solo Coast between stg 2 / 3 Vernier solo TS/Centaur/IDS - Second burn 3 3.5 4 Agena/Centaur - Second bum Third-stage bum Coast after stg 3 Second bum 5 Orbit Orbit Orbit ! 9/10/96 99 RTI