Appendix B -Saturn V Prelaunch-Launch Sequence

AS-509 Prelaunch Operations
Event Completed
LM Operations 30-Oct-70
Combined System Test 4-Dec-70
Unmanned Altitude Run 5-May-70
Manned Altitude Run 18-Sep-70
LM/SLA Mate 22-Oct-70
CSM Operations 3-Nov-70
Combined System Test 4-Dec-70
Unmanned Altitude Run 27-Aug-70
Manned Altitude Run 3-Sep-70
CSM/SLA Mate 31-Oct-70
Ordnance Installation 7-Nov-70
LV VAB Low Bay Operations 12-May-70
IU Low Bay Checkout 12-May-70
S-IVB Low Bay Checkout 12-May-70
S-II Low Bay Checkout 11-May-70
LV VAB High Bay Operations 29-Oct-70
SIC Erection 14-Jan-70
LV Erection 13-May-70
LV Electrical System Test 6-Oct-70
LV Malfunction Overall Test 21-Oct-70
LV Service Arm Overall Test 29-Oct-70
Spacecraft Erection 4-Nov-70
Space Vehicle VAB Operations 8-Nov-70
Transfer to Pad 9-Nov-70
Pad Operations 31-Jan-70
LV Power ON 11-Nov-70
Space Vehicle Overall Test 7-Dec-70
LV Flight Systems Test 11-Dec-70
SV Flight Electrical Mating 11-Dec-70
SV Back-up Guidance Test 14-Dec-70
SV Flight Readiness Test 15-Dec-70
SV Hypergolic Loading 8-Jan-71
S-IC RP-1 Loading 9-Jan-71
CDDT-Wet/Dry 18-Jan-71
SV Countdown Prep. 25-Jan-72
Countdown 31-Jan-71
Typical Prelaunch Sequence
(Selected Events from T -9:30:00.0 to Liftoff)
Time before First Motion
(HR:MIN:SEC)
Start Stop Event
9:30:00.0 LIFTOFF Switch LV Environmental Conditioning from Air to GN2
8:59:00.0 1:30:00.0 G&C System Checks
8:59:00.0 LIFTOFF ST-124M3 GN2 Sphere Pressurization
8:59:00.0 1:00:00.0 S-IVB Ambient GHe Supply Bottle Prepressurization
8:59:00.0 8:54:00.0 LVDC Sector Sum Check
8:57:00.0 6:27:00.0 S-IC LOX Tank Purge (GN2)
8:34:00.0 7:39:00.0 S-II LOX Tank Prepressurization (GN2)
8:34:00.0 7:42:00.0 S-II LH2 Tank Purge (GHe)
8:34:00.0 8:16:00.0 S-II LH2 Recirculation Line Purge (GHe)
8:15:00.0 8:00:00.0 S-IVB LOX Chilldown Pump Cavity Purge
8:15:00.0 LIFTOFF ST-124M3 System ON
8:15:00.0 Start LV Cryogenic Loading
8:00:00.0 7:55:00.0 Prepare to Launch Test
8:00:00.0 LIFTOFF IU Electrical Disconnect Purge
8:00:00.0 7:40:00.0 S-II Turbine Start Bottle Purge (GHe)
8:00:00.0 0:04:00.0 S-II Auxiliary Hydraulic Pump ON
8:00:00.0 3:28:00.0 Operate DEE-3 System
7:43:00.0 7:28:00.0 S-IVB LOX Tank Purge (GHe)
7:42:00.0 4:54:00.0 S-II LH2 Tank Preconditioning
7:40:00.0 7:28:00.0 S-II Engine Turbopump Purge
7:39:00.0 7:04:00.0 S-II LOX Tank Purge (GN2)
7:39:00.0 7:28:00.0 S-IVB J-2 Engine Turbopump Purge
7:31:00.0 4:11:00.0 S-IVB LH, Tank Purge (GHe)
7:28:00.0 7:13:00.0 S-II Engine Thrust Chamber Purge (GHe)
7:28:00.0 7:24:00.0 S-IVB LOX Tank Precool (0-5%)
7:24:00.0 7:07:00.0 S-IVB LOX Tank Fast Fill (5-96%)
7:07:00.0 7:04:00.0 S-IVB LOX Tank Slow Fill (96-99%)
7:05:00.0 LIFTOFF SIC Engine Thrust Conditioning
7:05:00.0 6:30:00.0 IU CCS Checks
7:04:00.0 6:54:00.0 S-II LOX Tank Precool (0-5%)
6:54:00.0 6:44:00.0 S-II LOX Tank Fast Fill (5-40%)
6:44:00.0 6:30:00.0 S-II LOX Tank Fast Fill (40-96%)
6:38:00.0 6:30:00.0 Preflight Command System Test, Houston
6:30:00.0 6:27:00.0 S-II LOX Tank Slow Fill (96-99%)
6:27:00.0 6:02:00.0 SIC LOX Precool
6:02:00.0 5:45:00.0 S-IC LOX Tank Slow Fill (0-6.5%)
5:45:00.0 4:57:00.0 S-IC LOX Tank Fast Fill (6.5-98%)
5:45:00.0 0:03:06.0 S-II LOX Tank Replenish
5:45:00.0 0:03:06.0 S-IVB LOX Tank Replenish
4:57:00.0 0:00:08.9 S-IC GHe Supply Bottle Pressurization
4:57:00.0 4:55:00.0 SIC LOX Tank Slow Fill (98-100%)
4:55:00.0 0:03:06.0 S-IC LOX Tank Replenish
4:54:00.0 4:36:00.0 S-II LH, Precool (0-5%)
4:36:00.0 4:16:00.0 S-II LH2
4:16:00.0 4:11:00.0 S-II LH2
4:11:00.0 LIFTOFF Q-Ball Power and Heaters ON
4:11:00.0 0:00:08.9 S-IVB LOX Tank GHe Supply Bottle Pressurization
4:11:00.0 3:58:00.0 S-IVB LH2 Precool (0-5%)
3:58:00.0 3:33:00.0 S-IVB LH2 Fast Fill (5-98%)
3:33:00.0 3:28:00.0 S-IVB LH2 Slow Fill (98-100%)
3:33:00.0 0:03:06.0 S-II LH2 Replenish
3:28:00.0 0:03:06.0 S-IVB LH2 Replenish
3:28:00.0 0:52:30.0 Astronaut Loading
1:40:00.0 1:10:00.0 EDS Test
1:00:00.0 0:35:00.0 S-IC Fuel Level Adjust
1:00:00.0 0:00:08.9 S-IVB Ambient GHe Supply Bottle Pressurization
0:57:00.0 0:47:00.0 Azimuth Laying
0:51:30.0 LIFTOFF Final CCS Checks
0:51:25.0 0:46:25.0 Preflight Command System Test
0:45:00.0 LIFTOFF Final Tracking System Check
0:43:00.0 0:05:00.0 CM Access Arm in Park Position
0:42:00.0 LIFTOFF LES Armed
0:42:00.0 LIFTOFF GNC System Checks
0:42:00.0 0:37:00.0 IU Gimbal Checks
0:40:00.0 0:32:00.0 Range Safety Command Checks (Closed Loop)
0:34:30.0 0:00:08.9 S-IVB Engine GHe Bottle Pressurization
0:31:30.0 0:30:00.0 S-II LH2> Chilldown Pump Test
0:31:30.0 0:30:00.0 S-IVB LOX/LH2 Chilldown Pump Test
0:30:00.0 0:26:00.0 Power Transfer Test
0:25:00.0 LIFTOFF Range Safety System ON
0:22:00.0 0:04:37.0 S-II Turbine Start Bottle Chilldown (GN2)
0:20:30.0 LIFTOFF Final SV Telemetry System Checks
0:20:00.0 0:14:30.0 S-IVB Turbine Start Bottle Purge
0:15:00.0 0:10:00.0 S-IVB Engine Thrust Chamber Purge
0:14:30.0 0:05:30.0 S-IVB Turbine Start Bottle Chilldown
0:13:00.0 0:08:00.0 S-II Engine Thrust Chamber Purge (GHe)
0:10:00.0 LIFTOFF Prepare to Launch Test
0:10:00.0 0:06:00.0 S-IC Fuel Jacket Topping (Glycol)
0:10:00.0 0:00:08.9 S-IVB Engine Thrust Chamber Chilldown
0:08:00.0 0:00:08.9 S-II Engine Thrust Chamber Chilldown
0:05:30.0 LIFTOFF S&A Devices Armed
0:05:30.0 0:05:00.0 S-IVB Turbine Start Bottle Pressurization
0:05:00.0 0:04:00.0 Remove Q-ball Cover
0:05:00.0 0:04:50.0 Retract and Lock CM Access Arm
0:04:37.0 0:03:07.0 S-II Turbine Start Bottle Pressurization
0:04:30.0 LIFTOFF Terminal Countdown Sequencer Armed
0:03:07.0 Start Automatic Sequence
0:03:07.0 0:00:30.0 S-II LOX Tank Prepressurization
0:02:47.0 0:00:08.9 S-IVB LOX Tank Prepressurization
0:01:37.0 0:00:04.1 SIC Fuel Tank Prepressurization
0:01:37.0 0:00:30.0 S-II LH2 Tank Prepressurization
0:01:37.0 0:00:08.9 S-IVB LH2 Tank Prepressurization
0:01:37.0 LIFTOFF SIC LOX Tank Prepressurization
0:00:50.0 Transfer to Internal Power
0:00:40.0 LIFTOFF S-IVB LH2 Vent Directional Control Flight Position ON
0:00:30.0 0:00:17.0 Retract and Lock S-IC Intertank Service Arm
0:00:30.0 LIFTOFF SIC Engine Hydraulic System Flight Activation
0:00:17.0 LIFTOFF Guidance Reference Release
0:00:16.2 0:00:11.0 Retract and Lock S-IC Forward Service Arm
0:00:08.9 0:00:06.7 S-IC Ignition Command
0:00:05.3 LIFTOFF Monitor S-IC Engine Thrust Buildup
0:00:01.0 LIFTOFF Monitor Thrust OK AII S-IC Engines
0:00:01.0 0:00:00.0 Holddown Arm Release
Typical Critical Event Sequence, First Opportunity TLI
(Event Times Are Based on AS-509 Launch Vehicle Operational Trajectory for 31 January 1971 Window, 72.067° Flight Azimuth)
Time from First Motion
(HR:MIN:SEC)		 Time from Reference
(HR:MIN:SEC)		 Event
-0:00:17.3 T1 -0:00:17.7 Guidance Reference Release
0:00:00.0 T1 -0:00:00.4 First Motion
0:00:00.4 T1 +0:00:00.0 Liftoff
0:00:01.4 T1 +0:00:01.0 Begin Tower Clearance Yaw Maneuver
0:00:09.4 T1 +0:00:09.0 End Yaw Maneuver
0:00:12.3 T1 +0:00:11.9 Pitch and Roll Initiation
0:01:09.0 T1 +0:01:08.6 Mach 1
0:01:25.5 T1 +0:01:25.1 Maximum Dynamic Pressure
0:02:15.0 T1 +0:02:14.6 S-IC Center Engine Cutoff
0:02:15.1 T2 +0:00:00.0 Set Time Base 2
0:02:42.8 T2 +0:02:27.7 Begin Tilt Arrest
0:02:44.8 T3 +0:00:00.0 S-IC Outboard Engine Cutoff
0:02:45.3 T4 +0:00:00.5 S-II Ullage Rocket Ignition
0:02:45.5 T4 +0:00:00.7 Signal to Separation Devices and S-IC Retrorockets
0:02:45.6 T3 +0:00:00.8 S-IC/S-II First Plane Separation Complete
0:02:46.2 T4 +0:00:01.4 S-II Engine Start Sequence Initiated
0:02:47.2 T3 +0:00:02.4 S-II Ignition (Start Tank Discharge Valve Opens)
0:02:49.2 T3 +0:00:04.4 S-II Engines at Mainstage
0:02:49.8 T3 +0:00:05.0 S-II Ullage Thrust Cutoff
0:03:15.5 T4 +0:00:30.7 S-II Aft Interstage Drop (Second Plane Separation)
0:03:21.2 T3 +0:00:36.4 LET Jettison (Crew Action)
0:03:25.6 T3 +0:00:40.8 Initiate IGM
0:07:43.8 T3 +0:04:59.0 S-II Center Engine Cutoff
0:07:52.2 T3 +0:05:07.4 MR Shift
0:09:16.67 T4 -0:00:00.01 S-II Outboard Engine Cutoff; Enable Chi Freeze
0:09:16.68 T4 +0:00:00.0 Set Time Base 4; Begin Chi Freeze
0:09:17.6 T4 +0:00:00.9 S-IVB Ullage Ignition
0:09:17.7 T4 +0:00:01.0 Signal to Separation Devices and S-II Retrorockets
0:09:17.8 T4 +0:00:01.1 S-II/S-IVB Separation
0:09:17.8 T4 +0:00:01.1 S-IVB Engine Start Sequence, First Burn
0:09:20.8 T4 +0:00:04.1 S-IVB Ignition (Start Tank Discharge Valve Opens)
0:09:23.3 T4 +0:00:06.6 S-IVB Engine at Mainstage
0:09:25.4 T4 +0:00:08.7 S-IVB Ullage Thrust End
0:09:26.1 T4 +0:00:09.4 End Chi Freeze
0:09:29.5 T4 +0:00:12.8 S-IVB Ullage Case Jettison
0:11:35.6 T4 +0:02:18.9 Begin Chi Freeze
0:11:43.4 T5 -0:00:00.2 S-IVB Cutoff, First Burn
0:11:43.6 T5 +0:00:00.0 Set Time Base 5
0:11:43.9 T5 +0:00:00.3 S-IVB APS Ullage Ignition
0:11:53.4 T5 +0:00:09.8 Parking Orbit Insertion
0:12:03.6 T5 +0:00:20.0 Initiate Maneuver to and Maintain Local Horizontal Alignment (CSM Forward, Heads Down)
0:12:03.7 T5 +0:00:20.1 Begin Orbital Guidance
0:12:42.6 T5 +0:00:59.0 LH2 Continuous Vent Open
0:13:10.6 T5 +0:01:27.0 S-IVB APS Ullage Cutoff
0:13:24.1 T5 +0:01:40.5 Begin Orbital Navigation
2:21:00.1 T6 +0:00:00.0 Begin S-IVB Restart Preparations
2:21:42.1 T6 +0:00:42.0 O2H2 Burner (Helium Heater) On
2:21:42.3 T6 +0:00:42.2 LH2 Continuous Vent Closed
2:29:16.4 T6 +0:08:16.3 S-IVB APS Ullage Ignition
2:29:16.9 T6 +0:08:16.8 Helium Heater Off
2:30:30.1 T6 +0:09:30.0 Initiate J-2 Fuel Lead
2:30:33.1 T6 +0:09:33.0 S-IVB APS Ullage Cutoff
2:30:38.1 T6 +0:09:38.0 S-IVB Reignition (Start Tank Discharge Valve Opens)
2:30:40.6 T6 +0:09:40.5 S-IVB Engine at Mainstage
2:33:55.6 T6 +0:11:55.5 MR Shift (First Opportunity Only)
2:36:33.8 T7 -0:00:00.2 S-IVB Engine Cutoff, Second Burn
2:36:34.0 T7 +0:00:00.0 Set Time Base 7
2:36:34.5 T7 +0:00:00.5 LH2 Continuous Vent Open
2:36:34.7 T7 +0:00:00.7 LOX Nonpropulsive Vent Open
2:36:34.8 T7 +0:00:00.8 LH2 Nonpropulsive Vent Open
2:36:37.6 T7 +0:00:03.6 Flight Control Coast Mode On
2:36:39.0 T7 +0:00:05.0 Enable SC Control of LV
2:36:43.8 T7 +0:00:09.8 Translunar Injection
2:39:04.7 T7 +0:02:30.7 LOX Nonpropulsive Vent Closed
2:39:04.9 T7 +0:02:30.9 LH2 Continuous Vent Closed
2:39:04.9 T7 +0:02:30.9 Initiate Maneuver to and Maintain Local Horizontal Alignment (CSM Forward, Heads Down)
2:51:34.0 T7 +0:15:00.0 LH2 Nonpropulsive Vent Closed Initiate Maneuver to and Maintain TD&E Attitude
2:51:34.0 T7 +0:15:00.0 CSM Separation (Variable)
3:01:34.0 T7 +0:25:00.0 CSM/LM Docking (Variable)
3:16:34.0 T7 +0:40:00.0 LH2 Nonpropulsive Vent Open
3:36:34.4 T7 +1:00:00.4 LH2 Nonpropulsive Vent Closed
3:51:34.0 T7 +1:15:00.0 SC/L Final Separation (Variable)
3:56:34.0 T7 +1:20:00.0 Initiate Maneuver to and Maintain
4:11:34.0 T7 +1:35:00.0 S-IVB Evasive Attitude (Variable)
(T8 -0:08:00.0) Set Time Base 8
4:19:34.0 T8 +0:00:00.0 S-IVB APS Ullage Ignition
4:19:35.2 T8 +0:00:01.2 S-IVB APS Ullage Cutoff
4:20:55.2 T8 +0:01:21.2 Initiate Maneuver to and Maintain LOX Dump Attitude
4:29:14.2 T8 +0:09:40.2 LH2 Continuous Vent Open
4:36:14.0 T8 +0:16:40.0 Start LOX Dump
4:40:54.0 T8 +0:21:20.0 LH2 Continuous Vent Closed
4:41:14.0 T8 +0:21:40.0 End LOX Dump
4:41:42.0 T8 +0:22:08.0 LOX Nonpropulsive Vent Open
4:42:54.2 T8 +0:23:20.2 LH2 Nonpropulsive Vent Open
4:42:59.0 T8 +0:23:25.0 Initiate Maneuver to and Maintain
5:59:34.0* T8 +1:40:00.0* S-IVB APS Impact Burn Attitude
6:29:34.0* T8 +2:10:00.0* S-IVB APS Ullage Ignition
6:33:35.0* T8 +2:14:01.0* S-IVB APS Ullage Cutoff

* Subject to update by DCS guidance commands to the LVDC after real-time assessment.