Changes and additions:
- October 8: Posting initial release
- November 11: Updating throughout

As always, all countdown events prior to the end of the T-minus nine-minute hold are targeted to the opening of the shuttle's launch window. For station flights, the shuttle must take off within five minutes or so of the moment Earth's rotation carries the launch pad into the plane of the station's orbit. NASA targets the middle of that window for launch. Please note that NASA rounds down, not up, for countdown calculations. The release of the final hold at T-minus nine-minutes is targeted to the actual launch time (times in EST).

NOTE: The following countdown is an extrapolation based on hold times in NASA's initial summary timeline. The timing of some events may change when a detailed countdown timeline is generated. Updates will be posted as warranted.

EST...........EVENT

11/11/08
	
09:30 PM......Call to stations
10:00 PM......Countdown begins

Wed  11/12/08

08:00 AM......Fuel cell reactant load preps
01:30 PM......MEC/SRB power up
02:00 PM......Clear crew module

02:00 PM......Begin 4-hour built-in hold
02:00 PM......Clear blast danger area
02:45 PM......Orbiter pyro-initiator controller test
02:55 PM......SRB PIC test
03:55 PM......Master events controller pre-flight BITE test

06:00 PM......Resume countdown
07:30 PM......Fuel cell oxygen loading begins
10:00 PM......Fuel cell oxygen load complete
10:00 PM......Fuel cell hydrogen loading begins
10:30 PM......Fuel cell hydrogen loading complete

Thu  11/13/08

01:30 AM......Pad open; ingress white room

02:00 AM......Begin 4-hour built-in hold
02:00 AM......Crew module clean and vacuum
02:30 AM......OMBUU demate
04:00 AM......Secure MLP interior

06:00 AM......Countdown resumes
06:00 AM......Main engine preps
06:00 AM......MECs 1 and 2 on; avionics system checkout
07:00 AM......Remove OMS engine covers, throat plugs
07:30 AM......Deflate RSS dock seals; tile inspection
08:00 AM......Tile inspection
12:00 PM......TSM prepped for fueling

02:07 PM......Begin 13-hour 30-minute hold
03:45 PM......Crew weather briefing
04:30 PM......OIS communications check
05:20 PM......JSC flight control team on station
06:30 PM......Comm activation
07:00 PM......Crew module voice checks
08:00 PM......Flight crew equipment late stow
08:30 PM......Debris inspection
11:30 PM......RSS to park position

Fri  11/14/08

12:30 AM......Final TPS, debris inspection
01:30 AM......Ascent switch list
03:00 AM......Crew sleep begins

03:30 AM......Resume countdown
03:30 AM......ASP cockpit config
03:50 AM......Pad clear of non-essential personnel
03:50 AM......APU bite test
04:40 AM......Fuel cell activation
05:30 AM......Booster joint heater activation
06:00 AM......MEC pre-flight bite test
06:15 AM......Tanking weather update
07:00 AM......Final fueling preps; launch area clear
07:30 AM......Red crew assembled
08:15 AM......Fuel cell integrity checks complete

08:30 AM......Begin 2-hour built-in hold (T-minus 6 hours)
08:40 AM......Safe-and-arm PIC test
09:23 AM......Crew wakeup
09:30 AM......External tank ready for loading
09:45 AM......Mission management team tanking meeting

10:30 AM......Resume countdown (T-minus 6 hours)
10:30 AM......LO2, LH2 transfer line chilldown
10:40 AM......Main propulsion system chill down
10:40 AM......LH2 slow fill
11:00 AM......Crew wakeup
11:10 AM......LO2 slow fill
11:15 AM......Hydrogen ECO sensors go wet
11:20 AM......LO2 fast fill
11:30 AM......LH2 fast fill
01:25 PM......LH2 topping
01:30 PM......LH2 replenish
01:30 PM......LO2 replenish

01:30 PM......Begin 2-hour 30-minute built-in hold (T-minus 3 hours)
01:30 PM......Closeout crew to white room
01:30 PM......External tank in stable replenish mode
01:45 PM......Astronaut support personnel comm checks
02:15 PM......Pre-ingress switch reconfig
02:30 PM......NASA TV coverage begins
02:33 PM......Crew breakfast/photo op (recorded)
03:25 PM......Final crew weather briefing
03:35 PM......Crew suit up begins

04:00 PM......Resume countdown (T-minus 3 hours)
04:05 PM......Crew departs O&C building
04:35 PM......Crew ingress
05:25 PM......Astronaut comm checks
05:40 PM......Hatch closure
06:20 PM......White room closeout

06:40 PM......Begin 10-minute built-in hold (T-minus 20m)
06:50 PM......NASA test director countdown briefing

06:50 PM......Resume countdown (T-minus 20m)
06:51 PM......Backup flight computer to OPS 1
06:55 PM......KSC area clear to launch

07:01 PM......Begin final built-in hold (T-minus 9m)
07:31 PM......NTD launch status verification
07:46:34 PM...Resume countdown (T-minus 9m)

07:48:04 PM...Orbiter access arm retraction
07:50:34 PM...Launch window opens
07:50:34 PM...Hydraulic power system (APU) start
07:50:39 PM...Terminate LO2 replenish
07:51:34 PM...Purge sequence 4 hydraulic test
07:51:34 PM...IMUs to inertial
07:51:39 PM...Aerosurface profile
07:52:04 PM...Main engine steering test
07:52:39 PM...LO2 tank pressurization
07:52:59 PM...Fuel cells to internal reactants
07:53:04 PM...Clear caution-and-warning memory
07:53:34 PM...Crew closes visors
07:53:37 PM...LH2 tank pressurization
07:54:44 PM...SRB joint heater deactivation
07:55:03 PM...Shuttle GPCs take control of countdown
07:55:13 PM...SRB steering test
07:55:27 PM...Main engine start (T-6.6 seconds)
07:55:34 PM...SRB ignition (LAUNCH)