Detailed Countdown Timeline

All times a.m. EDT.  10/28
T- L- Event EDT
-- 9:20:00 MST Rollback 08:28PM
-- 7:20:00 MST Secure 10:28PM
-- 5:20:00 Launch Mount 12:28
-- 5:00:00 Weather Balloon Release 12:48
-- 4:30.00 Establish Voice Communication 01:18
-- 4:25:00 Roadblocks Up 01:23
--   Clear Blast Danger Area  
-- 04:00:00 Weather Balloon Release 01:48
02:30:00 04:00:00 Countdown Clock Initialization 01:48
HOLDING   Second Stage HE Fill and Pressurization  
60-Minute   Countdown Initiation  
Hold   Countdown Brieifng  
    Redundant Inertial Flight Ctrl Assembly Act.  
  3:55:00 Weather Balloon Release 01:53
  3:22:00 Main Data Recorder Activation 02:26
  3:20:00 Prepress Complete 02:28
    SMD Poll  
    NAM Poll  
  3:17:00 NASA Launch Manager Poll 02:31
  3:13:00 LD Poll for Terminal Count 02:35
  3:11:00 LD Polls 02:37
  3:10:00 Pretask Briefing 02:38
    Launch Conductor Poll for Terminal Count  
  3:05:00 Launch Area Clear 02:43
2:30:00 03:00:00 Countdown Begins 02:48
COUNTING   Launch Area Clear Confirmation  
2:27:00 2:57:00 RIFCA Activation 02:51
2:26:00 2:56:00 Core Stage He and N2 Pressurization 02:52
2:20:00 2:50:00 Second Stage He Pressurization 02:58
    Guidance System activation  
2:10:00 2:40:00 Core Stage Fueling 03:08
1:45:00 2:15:00 RP-1 Load Complete 03:33
1:35:00 2:05:00 Weather Briefing 03:43
1:27:00 1:57:00 NLM LOX Loading Poll 03:51
1:25:00 1:55:00 Launch Director LOX Loading Poll 03:53
1:15:00 1:45:00 LOX Loading begins 04:03
    Blast Area Clear  
1:10:00 1:40:00 Weather Balloon Release 04:08
1:00:00 1:30:00 C-Band Transponder Beacon Checks 04:18
0:55:00 1:25:00 Weather Briefing 04:23
0:45:00 1:15:00 LOX at 100%; Systems Check 04:33
0:38:00 1:08:00 LOX Dump to 95% 04:40
    Weather Balloon Release  
0:37:00 1:07:00 Hydraulics System Activation 04:41
0:34:00 1:04:00 CDR Open Loop 04:44
0:26:00 0:56:00 Engine Gimbal Steering Profile Check 04:52
0:17:00 0:47:00 Link Checks 05:01
0:15:00 0:45:00 Weather Briefing 05:03
HOLDING   Launch Team Poll  
20-Minute   He and N2 Top Off  
Hold 0:40:00 Weather Balloon Release 05:08
  0:30:00 Ready Report 05:18
  0:29:00 Weather Briefing 05:19
0:15:00 0:25:00 LOX Top Off to 95% 05:23
COUNTING   Range Safety Radio Caommand Carrier Act.  
0:14:00 0:24:00 Range Safety Command Receiver Checks 05:24
    First Stage Fuel Tank Pressurization  
0:12:00 0:22:00 Wind Assessment 05:26
0:10:00 0:20:00 Load Relief 05:28
0:07:00 0:17:00 LOX Top Off to 99% 05:31
0:06:00 0:16:00 Weather Verification 05:32
    Spacecraft Status Check  
0.05:00 0:15:00 Launch Enable Switch to ON Position 05:33
    NAM Poll  
    SMD Poll  
0:04:00 0:14:00 Final Status Polls 05:34
HOLDING 0:12:00 Report Status 05:36
10-Minute 0:11:00 NLM Poll 05:37
Hold      
  0:07:00 Status Check 05:41
  0.06:30 NPP to Internal Power 05:42
  0:06:00 Launch Director GO/no GO; Range Clear 05:42
  0:05:00 Spacecraft in Launch Configuration 05:43
0:04:00 0:04:00 Range Safety System armed 05:44:01
COUNTING   Launcher to internal Power  
0:03:00 0:03:00 NASA Manager Status Verification 05:45:01
0:02:00 0:02:00 LOX Tank to Flight Pressure 05:46:01
0:01:20 0:01:20 LOX to 100% 05:46:41
0:01:10 0:01:10 Range Status Check 05:46:51
0:01:00 0:01:00 Launch Enable Switch to ON 05:47:01
0:00:30 0:00:30 LOX Fill and Drain Valve closed 05:47:31
0:00:13 0:00:13 GREEN Board Verification 05:47:48
0:00:10 0:00:10 Ignition System armed 05:47:51
0:00:07 0:00:07 GO for Main Engine Start 05:47:54
0.00:02.5 0.00:02.5 Main Engine Start 05:47:59
0:00:00.0 0:00:00.0 Booster Ignition 05:48:01
    Liftoff  

 

Launch Date October 28, 2011
Launch Time 5:48:01 a.m. - 5:57:11 a.m. EDT
Launch Site Vandenberg Air Force Base
  Space Launch Complex 2
Launch Opportunities Starting Oct. 25

Launch Window Opens

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Launch Vehicle Information
Ascent Data (Animation, Timeline, Map)


Countdown Timeline Diagram

Picture
Source: ULA Launch Press Kit