Space Shuttle Launch Countdown




 T-                        EVENTS                         CHNL    REMARKS

T-06H00M     THE COUNT HAS RESUMED                              

                                                                NTD,ALL 

               ********************************

               * NOTE: THE NEXT PLANNED HOLD  *

               * IS AT T-03H00M               *

               ********************************

             THIS IS THE RE-ENTRY POINT FOR

             24 HOUR SCRUB/TURNAROUND OPERATIONS

             PERFORM ET TPS ICE/FROST & DEBRIS            136   TBC,CICE

             EVALUATION

             ET READY FOR LOX & LH2 LOADING               232   NTD,TBC

             VERIFY NO INCREASE ABOVE BASELINE FOR        132   OTC,CHGD

             H2 CONCENTRATION PRIOR TO START OF LOX/LH2

             LOADING IN THE FOLLOWING LOCATIONS:

                  ORBITER PAYLOAD BAY

                  ORBITER LOWER MID BODY

                  ORBITER AFT FUSELAGE

             ORBITER READY FOR LOX & LH2 LOAD             232   NTD,OTC

             PROCEED WITH LOX & LH2 LOAD                  232   NTD,TBC

                                                          136

             INITIATE LOX TRANSFER LINE CHILLDOWN         136   NTD,TBC,CLOX

                                                          232

             INITIATE LH2 TRANSFER LINE CHILLDOWN         136   NTD,TBC,CLHY

                                                          232




 T-                        EVENTS                         CHNL    REMARKS

T-06H00M     PERFORM OMS PROP TANK REPRESSURIZATION       132   OTC,COOS
(CONT'D)

             VERIFY SRB NOZZLE FLEX BEARING & SRB NOZZLE  136   TBC,CPWR

             TO CASE JOINT TEMPERATURE REQUIREMENTS

             ACTIVATE LCC MONITORING SOFTWARE             136   TBC,OTC

T-05H50M     LH2 FACILITY & ORBITER CHILLDOWN COMPLETE.   136   NTD,TBC,CLHY

             INITIATE LH2 SLOW FILL TO 5% SENSORS WET     232

             LOX TRANSFER LINE CHILLDOWN COMPLETE         136   NTD,TBC,CLOX 

                                                          232

             INITIATE ORBITER MPS CHILLDOWN                     NTD,TBC,CLOX

T-05H22M     PERFORM IMU PREFLIGHT CALIBRATION            132   OTC,CGNC

                                                                (2 HRS 45 MINS)

 
T-05H20M     ORBITER MPS CHILLDOWN COMPLETE.   INITIATE   136   NTD,TBC,CLOX

             LOX SLOW FILL.  GMT _______                  232

T-05H15M     LH2 ENGINE CUT OFF SENSORS WET               136   NTD,TBC,CLHY

                                 GMT _______              232

T-05H10M     LOX TRANSITION TO FAST FILL COMPLETE.        136   NTD,TBC,CLOX  

             NOW IN FAST FILL TO 98%                      232

T-05H00M     ET LH2 5% SENSOR WET.   GMT________          136   NTD,TBC,CLHY

             INITIATE LH2 FAST FILL TO 98%                136   CLHY

             MPS LH2 RECIRC PUMPS ACTIVATED MOMENTARILY   132   OTC,CMPS,CEPD

                                                                MONITOR AFT

                                                                FUSELAGE AND ET

                                                                INTERTANK FOR

                                                                ANY H2 CHANGE




 T-                        EVENTS                         CHNL    REMARKS

T-04H40M     MPS LH2 RECIRC PUMP ACTIVATION COMPLETE      132   OTC,CMPS

T-04H00M     PERFORM MILA ANTENNA ALIGNMENT               232   NTD,MILA,CCSE

                                                                *FLT(Houston)

                                                                (1 HOUR)

             PERFORM LH2 ET ULLAGE PRESSURE TRANSDUCER    132   NTD,TBC,CLHY

             NUMBER 4 VERIFICATION                        232   *FLT

T-03H45M     LH2 98% SENSOR IS WET.  INITIATE TOPPING     136   CLHY

             TO 100%.  GMT ________                       232

             ET BIPOD HEATERS ARE ACTIVATED               136   TBC,CEPD

                                                                 (WILL OCCUR

                                                                 APPROX 4 MIN

                                                                 AFTER PREVIOUS

                                                                 STEP)

             PERFORM ORBITER/GSE PIC RESISTANCE TEST      232   NTD,OTC,CEPD 

                                                          132

             PERFORM SRB/ET PIC RESISTANCE TEST           232   NTD,TBC,CPWR

                                                          136

             ASSEMBLE ICE CREW & CLOSEOUT CREW FOR        132   NTD,OTC,TBC

             PAD ENTRY                                    232   *SEC

                                                          136

T-03H30M     SWITCH TO MILA SECONDARY ANTENNA & PROCEED   232   NTD,MILA

             WITH ALIGNMENT




 T-                        EVENTS                         CHNL    REMARKS

T-03H10M       *************************************     232    NTD,ALL

               *  THE COUNTDOWN CLOCK WILL HOLD AT *

               *  T-03H00M                          *

               *************************************

T-03H05M     LH2 TOPPING IS COMPLETE                     136   NTD,TBC,CLHY

             INITIATE REPLENISH                          232   

             LOX IN STABLE REPLENISH                     136   NTD,TBC,CLOX

                                                         232

             LH2 IN STABLE REPLENISH                     136   NTD,TBC,CLHY

                                                         232

T-03H00M     MILA ANTENNA ALIGNMENT COMPLETE             232   NTD,MILA,OTC

             RESET ORBITER VENT DOOR COMMANDS            132

             PERFORM T-3 HR SNAPSHOT ON FLIGHT CRITICAL   132   OTC,CDPS

             & PAYLOAD MDMS




 T-                        EVENTS                         CHNL    REMARKS

T-03H00M &    THE COUNTDOWN CLOCK IS HOLDING AT T-03H00M   232    NTD,ALL
HOLDING

                                                                 PLANNED HOLD

                                                                 IS 2 HOURS

                 **************************************

                 *THE NEXT PLANNED HOLD IS AT T-20M00S*

                 **************************************

             ICE TEAM READY FOR PAD ENTRY                 232   NTD,*ICE

             CLEAR ICE TEAM & CLOSEOUT CREW TO PAD        232   NTD,SAFETY

                                                                SECURITY 

             PERFORM ICE/DEBRIS INSPECTION                105   NTD,*ICE

             INGRESS ORBITER CREW COMPARTMENT             232   NTD,OTC,OVCC

                                                          132

             GO FOR FLIGHT CREW WAKE UP                   232   NTD

             PERFORM COMM CHECKS                          132   OTC,ASP

             ALL ORB TEST TEAM SWITCH TO CHNL 212         212   OTC

             CONFIGURE & INSPECT CREW MODULE FOR CREW     212   OTC,ASP,OVCC

             INGRESS

             PERFORM POTABLE SUPPLY WATER ADJUST          212   OTC,CECL

             PERFORM IMU PRE-FLIGHT CALIBRATION           212   OTC,CGNC

                    NOT PERFORMED____________                   (CONTINGENCY)

             PERFORM ER OPEN LOOP CHECKS                  132   NTD,OTC,CCSE

                                                                CBRS, RANGE

                                                          232

                                                          175

             ER OPEN LOOP CHECK COMPLETE                  232   NTD,OTC,CCSE

                                                                CBRS, RANGE   




 T-                        EVENTS                         CHNL    REMARKS

T-03H00M &   VERIFY 4 HR 15 MIN JIMSPHERE HAS BEEN        232   NTD,SRO
HOLDING      RELEASED
(CONT'D)

             PERFORM FLIGHT CREW WEATHER BRIEFING         232   NTD, ASTRONAUTS

                                                                RANGE WEATHER

             INSTALL LIOH CANISTERS                       212   OTC,CECL,OVCC

             POWER UP SRB TRACKING                        232   NTD,TBC,CBRS

             SYSTEM                                       136   CPWR

                   NOT PERFORMED _______________

             RESUME THE COUNT IN 5 MINUTES                232   NTD,ALL




 T-                        EVENTS                         CHNL    REMARKS

T-03H00M     THE COUNT HAS RESUMED                              NTD,ALL 

             ************************************

             *  NOTE: THE NEXT PLANNED HOLD IS  *

             *  AT T-20 MINUTES                 *

             ************************************

             ICE/DEBRIS INSPECTION COMPLETE               232   NTD,*ICE

             PRESSURIZE MPS HELIUM TANKS                  212   OTC,CMPS

                                                                (30 MINUTES)

             MONITOR PAYLOAD BAY & MIDBODY DURING         212   OTC,CHGD

             HELIUM TANK PRESS

             PERFORM SRB RGA POWER UP & TORQUE TEST       136   TBC,CPWR

             ACTIVATE SRB RGA LCC EXCEPTION               136   TBC,CPWR

             MONITORING

T-02H55M     FLIGHT CREW DEPART O&C BUILDING TO PAD       232   NTD,OTC

                                                          212

   

             IDENTIFY ANY COLLISION AVOIDANCE             232   NTD,SRO

             TIMES FOR THIS LAUNCH WINDOW OR

             LAUNCH PERIOD

T-02H45M     ICE DEBRIS REPORT                            232   NTD,LD,MMT

                                                                SPE

             VERIFY NO VIOLATION OF LAUNCH COMMIT         232   NTD,OTC,TBC

             CRITERIA                                     212   STM,LPS,SPE

                                                          136   PTC,MILA,*FLT

                                                          134   SRO

T-02H40M     VERIFY TLA SITES                                   LRD 




 T-                        EVENTS                         CHNL    REMARKS

T-02H30M     SWITCH STANDBY FRONT END PROCESSORS TO RF    212   OTC,LPS

             MPS HELIUM TANK PRESSURIZATION IS COMPLETE   212   OTC,CMPS

             PERFORM ET LIQUID LEVEL SENSOR CHECKS        232   NTD,TBC,OTC

                                                          136   (15 MINUTES)

                                                          212

             PERFORM SRB MDM COUNTDOWN VERIFICATION       232   NTD,TBC,CDPS

                                                          136   CPWR

                                                                (15 MINUTES)

  

             INGRESS FLIGHT CREW & SEATS                  212   NTD,OTC,OVCC

                                                                ASP,ASTRONAUTS

T-02H15M     ET LIQUID LEVEL SENSOR CHECKS COMPLETE       212   OTC,TBC,NTD

T-02H10M     PERFORM POST INGRESS SWITCH RECONFIGURATION  212   OTC,ASP

T-02H00M     PERFORM GLS INITIALIZATION                   212   OTC,TBC,CGLS

             REPORT STATUS IN RETRIEVAL AREA              135   LRD

             ACTIVATE SRB HPU GAS GENERATOR HEATERS       232   NTD,TBC,CBHY

                                                          136

T-01H55M     PERFORM FIRST MOTION SIMULATED SIGNAL TEST   232   NTD,SRO,STM 

                                                          111

T-01H50M     PERFORM ETR SRSS VERIFICATION TEST           232   NTD,SRO,CBRS 




 T-                        EVENTS                         CHNL    REMARKS

T-01H35M     VERIFY ALL SYSTEMS READY FOR CREW MODULE     212   OTC,ALL

             CLOSEOUT

T-01H30M     PERFORM AIR TO GROUND VOICE CHECKS           232   NTD,OTC

             PERFORM SRM CHAMBER PRESSURE VERIFICATION    136   TBC,CISL

T-01H20M       **************************************     232   NTD,ALL

               * COUNTDOWN CONTINGENCY HOLD POINT   *

               **************************************

             THE COUNTDOWN CLOCK WILL HOLD FOR ________

             CLOSEOUT CREW COMPARTMENT HATCH              212   OTC,OVCC

            PERFORM ER OPEN LOOP AUTOMATIC COMMAND        232   NTD,SRO

            CARRIER CONTROL VALIDATION TESTS

T-01H10M     PERFORM ETR HOLDFIRE CHECKS                  232   NTD,SRO

                                                                (L-01H30M)

             PERFORM FINAL COLLISION AVOIDANCE UPDATE     232   NTD,SRO

             PERFORM CABIN LEAK CHECK                     212   OTC,CECL

T-01H00M     SRM CHAMBER PRESSURE VERIFICATION            136   CISL,TBC 

             IS COMPLETE




 T-                        EVENTS                         CHNL    REMARKS

T-01H00M        ********************************
(CONT-D)        * NOTE: TIME CHANGE TO MINUTES *

                * AND SECONDS                  *

                ********************************

T-55M00S     PERFORM S-BAND SYSTEM HIGH POWER/FM          232   NTD,MILA,LPS

             ACTIVATION                                         CCSE  

T-50M00S     PERFORM TERMINAL COUNT SRSS CLOSED LOOP      232   NTD,SRO,TBC

             TEST                                         136   CBRS

T-45M00S     PERFORM GLS MAINLINE ACTIVATION              212   OTC,CGLS

             PERFORM ORB/SRB LDB REDUNDANCY CHECKS        136   OTC,LPS,TBC

                                                          212

T-40M00S     GLS PRESEQUENCING HAS STARTED                212   CGLS,OTC,TBC

             FINAL CABIN LEAK CHECKS COMPLETE             212   CECL,OTC,NTD

             PERFORM CABIN VENT                           212   OTC,CECL,CDR

T-32M00S     PERFORM PASS/BFS TRANSFER PREPARATION        212   OTC,CDPS

T-30M00S     PERFORM OMS GN2 PRESSURIZATION               212   OTC,COOS

T-29M00S     PERFORM MAIN ENGINE CONTROLLER PREFLIGHT     212   OTC,CCME

             BITE CHECK




 T-                        EVENTS                         CHNL    REMARKS

T-22M00S     PERFORM PASS-BFS TRANSFER                    212   OTC,CDPS

             *****************************************

             * THE COUNTDOWN CLOCK WILL HOLD AT T-20 *    232   NTD,ALL

             *****************************************

             CLOSE CABIN VENT VALVES                      212   OTC,CECL,CDR

T-20M00S     CLEAR CLOSEOUT CREW FROM PAD                 212   NTD,OTC,OVCC




 T-                        EVENTS                         CHNL    REMARKS

T-20M00S &  THE COUNTDOWN CLOCK IS HOLDING AT T-20       232   NTD,ALL
HOLDING      MINUTES FOR A PLANNED HOLD OF 10 MINUTES     212

                                                          136

             REPORT HOLD TIME CONSTRAINTS                 232   NTD,SPE

             REPORT LOX DRAINBACK HOLD TIME               232   NTD, *FLT

             VERIFY CONSOLE PROGRAMS                      232   NTD,OTC,TBC

                                                          212   PTC,LPS 

                                                          136

             20 MINUTE RECYCLE ENTRY 

             ALL TEST TEAM PERSONNEL SWITCH TO CHNL 212   232   NTD,ALL 

             VERIFY STATUS OF LANDING SITES                     LRD

             T-20 MIN BRIEFING:                                 NTD

                LAUNCH WINDOW OPENS.   GMT __________

                LAUNCH WINDOW CLOSES.  GMT __________

                COLLISON AVOIDANCE (COLA) TIME FRAMES

                               START.  GMT __________

                               END.    GMT __________

                L0x DRAIN BACK  HOLD TIME  __________

             IMU PREFLIGHT ALIGNMENT IS COMPLETE.         212   CDPS,OTC,NTD 

             READY FOR TRANSITION TO OPS 1




 T-                        EVENTS                         CHNL    REMARKS

T-20M00S &  ACTIVATE GNC PROFILE MONITOR                        OTC,CGNC
HOLDING
(CONT-D)

               ****************************************

               * NOTE: AFTER T-20 MINUTES, ALL PROB-  *

               * LEMS OR TRENDS THAT REQUIRE A CDC    *

               * HOLD WILL BE REPORTED TO THE NTD ON  *

               * CHANNEL 212 TOGETHER WITH RECOMMEN-  *

               * DATION.  AFTER T-5 MIN., ANY HOLD    *

               * MANUAL OR GLS, SHOULD BE ACCOMPANIED *

               * BY A DESCRIPTION OF THE PROBLEM AND  *

               * A RECOMMENDATION.  THE COUNT CLOCK   *

               * WILL CONTINUE UNTIL T-31 SEC UNLESS  *

               * THE RECOMMENDATION TO HOLD AT THE    *

               * NEXT MILESTONE IS NECESSARY.         *

               ****************************************

            GLS MILESTONES:

                  T-09M00S   -   GLS SEQ START

                  T-07M30S   -   OAA RETRACT

                  T-05M00S   -   APU START

                  T-04M00S   -   PURGE SEQ 4

                  T-02M55S   -   LOX PRESSURIZATION

                  T-01M57S   -   LH2 TERM REPLENISH

                  T-00M31S   -   GLS GO FOR GPC AUTO SEQ




 T-                        EVENTS                         CHNL    REMARKS

T-20M00S &      *************************************
HOLDING          * AT T-9 MINUTES WHEN A "GO" IS     *
(CONT-D)         * GIVEN, IT INDICATES THAT THE      *

                 * REPORTING ELEMENT IS FREE OF PROB-*

                 * LEMS WHICH COULD PREVENT A SUC-   *

                 * CESSFUL LAUNCH.  IF A HOLD COMMAND*

                 * IS REQUESTED AND ISSUED BETWEEN   *

                 * T-9 MINUTES AND T-31 SECONDS, THE *

                 * COUNTDOWN CLOCK WILL BE RESTARTED *

                 * UPON SUCCESSFUL RESOLUTION OF THE *

                 * PROBLEM WITHOUT A "GO" SURVEY     *

                 * MADE OF ALL ELEMENTS.  AFTER T-31 *

                 * SECONDS, ONLY CUTOFF IS AVAILABLE,*

                 * AND WILL RESULT IN A RECYCLE TO   *

                 * T-20 MINUTES.  FOR A CUTOFF,      *

                 * PROWORDS "CGLS GIVE CUTOFF" WILL  *

                 * BE USED.                          *

                 *************************************




 T-                        EVENTS                         CHNL    REMARKS

T-20M00S   THE COUNTDOWN HAS RESUMED                     232   NTD,ALL    

                                                          212

                ****************************

                * NOTE: THE NEXT HOLD WILL *

                * BE AT T-9 MINUTES        *

                ****************************

             PERFORM FUEL CELL PURGE                      212   OTC,CFCP

             OPS TRANSITION IS COMPLETE                   212   CDPS,OTC,NTD

T-18M30S     BACKUP FLT SYSTEM TO OPS 1 TRANSITION        212   CDR,OTC,NTD

             IS COMPLETE

T-18M00S     PERFORM T-20 MINUTE GPC DUMP                 212   OTC,CDPS,CVFS

                                                                (7 MINUTES)

T-16M00S     PERFORM BACKUP FLT SYSTEM PREFLIGHT          212   NTD,*FLT,CVFS 

             UPLINK LOADING

             VERIFY WATER SPRAY BOILER QUANTITY                 OTC,CHYD 

             PERFORM MPS HELIUM RECONFIGURATION           212   OTC,CDR

T-15M00S     OMS/RCS CROSSFEED VALVES CONFIGURED          212   COOS,OTC,NTD

             FOR FLIGHT

             INITIATE SRB AFT SKIRT GN2 PURGE HIGH        136   CPVD,CBHY 

             FLOW RATE FOR LEFT & RIGHT SRBs                    TBC,NTD

T-13M00S     FUEL CELL PURGE IS COMPLETE                  212   CFCP,OTC

             ADJUST FUEL CELL LOADS                       212   OTC,CFCP




 T-                        EVENTS                         CHNL    REMARKS

T-12M00S     T-20 MINUTE GPC DUMP IS COMPLETE             212   CVFS,CDPS,OTC

             THE  COUNTDOWN CLOCK WILL HOLD AT            212   NTD,ALL    
             T-9  MINUTES

T-09M30S     VERIFY SRB HPU LEVELS                        GLS   CGLS
                                                                (Auto Check)

T-09M00S &   THE COUNTDOWN CLOCK IS HOLDING AT            232   NTD,ALL 
HOLDING      T-9 MINUTES.  PLANNED HOLD IS __ MINUTES     212
             REDUCE PAYLOAD BAY PURGE FLOWRATE                  NTD,OTC,PTC    
             IF GREATER THAN 180 LBS/MIN                        CPVD
                    NOT PERFORMED__________________             L-17M00S
             NTD LAUNCH READINESS POLL OF                       NTD,ALL 
             SHUTTLE LAUNCH TEAM
             PERFORM NSTS OPERATIONS MANAGER'S                  MMT CHAIRMAN 
             LAUNCH READINESS CHECK
             VERIFY CAPE WEATHER FORECASTS MEETS LAUNCH         LD,*WEA

             WEATHER CRITERIA

             THE COUNTDOWN CLOCK WILL RESUME IN 4         232   NTD,ALL 

             MINUTES                                      212

             PERFORM HGDS & BACKUP HGDS AUTO              212   OTC,CHGD

             CALIBRATION

             REMOVE SRB IGNITER HEATER POWER                    TBC,CPWR 

                                                                (L-10M00S)

             RESUME THE COUNT                             232

                                                          212   NTD ALL




 T-                        EVENTS                         CHNL    REMARKS

T-09M00S     THE COUNT HAS RESUMED                              NTD ALL

             GLS AUTO SEQUENCE HAS BEEN INITIATED         GLS   CGLS,ALL   

             SELECT PAYLOAD BAY SAMPLE LINE                     OTC,CHGD

T-07M30S     RETRACT ORBITER ACCESS ARM                   GLS   GLS(Auto)

T-07M00S     SELECT MIDBODY SAMPLE LINE                         OTC,CHGD

T-06M15S     PERFORM APU PRE-START                        212   OTC,PLT

             SELECT ET INTERTANK SAMPLE LINE                    OTC,CHGD

T-05M00S     GO FOR APU START                             GLS   CGLS,OTC,PLT

                                                          212

T-04M55S     VERIFY ET/SRB RANGE SAFETY SYSTEM SAFING     GLS   CGLS (Auto)

             & ARM DEVICE ARMED

             VERIFY SRM IGNITION SAFING & ARM DEVICE      GLS   CGLS (Auto)

             ARMED

             TERMINATE LOX REPLENISH                      GLS   CGLS (Auto)

T-04M48S     CLOSE LOX INBOARD F&D VALVE                  GLS   CGLS (Auto)

  
T-04M35S     OPEN LOX DRAIN VALVE                         GLS   CGLS (Auto)

T-04M30S     MAIN FUEL VALVE HEATERS OFF                  GLS   CMPS

T-04M00S     INITIATE SSME PURGE SEQUENCE  4              GLS   CGLS (Auto)




 T-                        EVENTS                         CHNL    REMARKS


T-04M00S     VERIFY SSME VALVE MOVEMENT IN THE                  CGLS (Auto)
(CONT'D)     CLOSE DIRECTION

T-03M55S     INITIATE ORBITER AERO SURFACES PROFILE       GLS   CGLS (Auto)

             CHECK

T-03M30S     INITIATE MPS GIMBAL PROFILE CHECKS           GLS   CGLS (Auto)

T-03M03S     MPS ENGINES TO START POSITION                GLS   CGLS (Auto)

             VERIFY BODY FLAP TO LAUNCH POSITION          GLS   CGLS (Auto)

T-03M00S     SELECT AFT FUSELAGE SAMPLE LINE                    OTC,CHGD 

T-02M55S     INITIATE ET LOX PRESSURIZATION               GLS   CGLS (Auto)

             TERMINATE SSME GN2 PURGE                     GLS   CGLS (Auto)

T-02M50S     TERMINATE GOX VENT HOOD PURGE                GLS   CGLS (Auto)

             RETRACT GOX VENT HOOD                        GLS   CGLS (Auto)

T-02M35S     PRSD TRANSFER TO INTERNAL REACTANTS          GLS   CGLS (Auto)

T-02M00S     CLOSE VISORS                                 212   OTC,CDR

T-01M57S     TERMINATE LH2 REPLENISH                      GLS   CGLS (Auto)

             CLOSE LH2 TOPPING VALVE                      GLS   CGLS (Auto)

             CLOSE LH2 VENT VALVE                         GLS   CGLS (Auto) 




 T-                        EVENTS                         CHNL    REMARKS

T-01M46S     INITIATE LH2 PREPRESS                        GLS   CGLS (Auto)

T-01M30S     T-1 MINUTE 30 SECONDS                        212   NTD,ALL

             ET BIPOD HEATERS OFF                         GLS   CGLS (Auto)

T-01M00S     T-1 MINUTE                                   212   NTD,ALL

T-00M55S     PERFORM SRB FWD MDM LOCKOUT                  GLS   CGLS (Auto)

             VERIFY SRB MDM CRITICAL COMMANDS             GLS   CGLS (Auto)

T-00M50S     GROUND POWER REMOVAL                         GLS   CGLS (Auto)

T-00M48S     CLOSE LOX & LH2 OUTBOARD FILL & DRAIN        GLS   CGLS (Auto)

             VALVES

             DEACTIVATE SRB JOINT HEATERS                 GLS   CGLS (Auto)

                                                          212

T-00M31S     GLS GO FOR AUTO SEQUENCE                     GLS   CGLS (Auto)

                                                          212

             ARM CUT OFF                                  GLS   CGLS (Manual)

             INITIATE RSL5                                GLS   CGLS (Auto)

             **************************************

             * NOTE: AFTER THIS TIME, ONLY CUT     *

             * OFF IS AVAILABLE & WILL RESULT IN   *

             * GLS RECYCLING TO T-20 MINUTES &     *

             * HOLDING                             *

             ***************************************

             ORB VENT DOOR SE9 START                      GPC   CGLS (Auto)

T-00M28S     START SRB APU'S                              GLS   NTD,ALL

T-00M26S     START SRB APU'S                              GLS   CGLS (Auto)

T-00M25S     25 SECONDS                                   212   NTD,ALL

T-00M21S     START SRB GIMBAL TEST                        GLS   CGLS (Auto)

T-00M20S     20 SECONDS                                   212   NTD,ALL

T-00M16S     ACTIVATE SOUND SUPPRESSION WATER             GLS   CGLS (Auto)

T-00M15S     15 SECONDS                                   212   NTD,ALL 

T-00M13S     PERFORM SRB AFT MDMS LOCKOUT                 GLS   CGLS (Auto)

             VERIFY LH2 HIGH POINT BLEED VALVE CLOSED     GLS

             TERMINATE MPS HELIUM FILL                    GLS

T-00M10S     10 SECONDS                                   212   NTD,ALL

       

             FREE HYDROGEN BURN OFF SYSTEM IGNITION       GLS   CGLS (Auto)

             GLS GO FOR MAIN ENGINE START                 GLS

                                                          212

             REMOVE ET/SRB RANGE SAFETY INHIBITS          GLS   CGLS (Auto)

T-00M6.6S    MAIN ENGINE 3 START COMMAND                  GPC   RSLS (Auto)

T-00M6.48S   MAIN ENGINE 2 START COMMAND                  GPC   RSLS (Auto)

T-00M6.36S   MAIN ENGINE 1 START COMMAND                  GPC   RSLS (Auto)

T-00M00S     T-ZERO  SRB IGNITION                         212   RSLS (Auto)

             SRB HOLDDOWN RELEASE COMMAND

                  LIFTOFF






Authors: Condensed from S0007 Launch Countdown Procedure
Hypertexed-by: Jim Dumoulin / NASA and Paula Shawa / Sherikon
Last Updated Tuesday June 20 17:27:09 EDT 1995

Jim Dumoulin (dumoulin@titan.ksc.nasa.gov)