Spaceflight Now



STS-133 Countdown Timeline
COMPILED BY WILLIAM HARWOOD
Updated: February 23, 2011


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The launch window is roughly 10 minutes long. To maximize ascent performance, NASA targets the middle of the window. A final hold in the countdown at the T-minus nine-minute mark will be extended as required to hit the desired launch time.


HH...MM...SS...EST........EVENT

Mon  02/21/11

...............02:30 PM......Call to stations
73...45...00...03:00 PM......Countdown begins

Tue  02/22/11

63...45...00...01:00 AM......Fuel cell reactant load preps
58...15...00...06:30 AM......MEC/SRB power up
57...45...00...07:00 AM......Clear crew module

57...45...00...07:00 AM......Begin 4-hour built-in hold
57...45...00...07:00 AM......Clear blast danger area
57...00...00...07:45 AM......Orbiter pyro-initiator controller test
56...50...00...07:55 AM......SRB PIC test
55...50...00...08:55 AM......Master events controller pre-flight BITE test
53...45...00...11:00 AM......Resume countdown

52...15...00...12:30 PM......Fuel cell oxygen loading begins
49...45...00...03:00 PM......Fuel cell oxygen load complete
49...45...00...03:00 PM......Fuel cell hydrogen loading begins
47...15...00...05:30 PM......Fuel cell hydrogen loading complete
46...15...00...06:30 PM......Pad open; ingress white room

45...45...00...07:00 PM......Begin 8-hour built-in hold
45...45...00...07:00 PM......PRSD offload
44...45...00...08:00 PM......Crew module clean and vacuum
41...45...00...11:00 PM......Remove APU vent covers
41...15...00...11:30 PM......OMBUU demate

Wed  02/23/11

40...45...00...12:00 AM......SSME throat plug removal
37...45...00...03:00 AM......Countdown resumes

37...45...00...03:00 AM......Main engine preps
37...45...00...03:00 AM......MECs 1 and 2 on; avionics system checkout
34...45...00...06:00 AM......FRCS Tyvek cover remova/inspect
31...15...00...09:30 AM......Deflate RSS dock seals; tile inspection
30...45...00...10:00 AM......Tile inspection
30...45...00...10:00 AM......TSM prepped for fueling
29...55...26...10:49 AM......Crew orbiter/payload briefings

29...45...00...11:00 AM......Begin 13-hour 25-minute hold
28...15...00...12:30 PM......RSS rotation preps
28...15...00...12:30 PM......OIS communications check with JSC
27...25...00...01:20 PM......JSC flight control team on station
26...15...00...02:30 PM......Comm activation
25...45...00...03:00 PM......Crew module voice checks
24...45...00...04:00 PM......L-1 engineering briefing
24...27...00...04:18 PM......Crew weather briefing
23...45...00...05:00 PM......Flight crew equipment late stow
20...45...00...08:00 PM......RSS to park position
19...45...00...09:00 PM......Final TPS, debris inspection
19...15...00...09:30 PM......Ascent switch list

Thu  02/24/11

16...20...00...12:25 AM......Resume countdown

16...00...00...12:45 AM......Pad clear of non-essential personnel
16...00...00...12:45 AM......APU bite test
15...10...00...01:35 AM......Fuel cell activation
14...20...00...02:25 AM......Booster joint heater activation
13...50...00...02:55 AM......MEC pre-flight bite test
13...35...00...03:10 AM......Tanking weather update
12...50...00...03:55 AM......Final fueling preps; launch area clear
12...20...00...04:25 AM......Red crew assembled
11...35...00...05:10 AM......Fuel cell integrity checks complete

11...20...00...05:25 AM......Begin 2-hour built-in hold (T-minus 6 hours)
11...10...00...05:35 AM......Safe-and-arm PIC test
10...32...00...06:13 AM......Crew wakeup
10...20...00...06:25 AM......External tank ready for loading
10...02...00...06:43 AM......Mission management team tanking meeting
09...20...00...07:15 AM......NASA TV fueling coverage begins
09...20...00...07:25 AM......Resume countdown (T-minus 6 hours)

09...20...00...07:25 AM......LO2, LH2 transfer line chilldown
09...10...00...07:35 AM......Main propulsion system chill down
09...10...00...07:35 AM......LH2 slow fill
08...40...00...08:05 AM......LO2 slow fill
08...35...00...08:10 AM......Hydrogen ECO sensors go wet
08...30...00...08:15 AM......LO2 fast fill
08...20...00...08:25 AM......LH2 fast fill
06...25...00...10:20 AM......LH2 topping
06...20...00...10:25 AM......LH2 replenish
06...20...00...10:25 AM......LO2 replenish

06...20...00...10:25 AM......Begin 2-hour 30-minute built-in hold (T-minus 3 hours)
06...20...00...10:25 AM......Closeout crew to white room
06...20...00...10:25 AM......External tank in stable replenish mode
06...17...00...10:28 AM......Ascent flight control team on console
06...05...00...10:40 AM......Astronaut support personnel comm checks
05...35...00...11:10 AM......Pre-ingress switch reconfig
05...15...00...11:30 AM......NASA TV launch coverage begins
04...25...00...12:20 PM......Final crew weather briefing
04...15...00...12:30 PM......Crew suit up begins
03...50...00...12:55 PM......Resume countdown (T-minus 3 hours)

03...45...00...01:00 PM......Crew departs O&C building
03...15...00...01:30 PM......Crew ingress
02...25...00...02:20 PM......Astronaut comm checks
02...00...00...02:45 PM......Hatch closure
01...30...00...03:15 PM......White room closeout

01...10...00...03:35 PM......Begin 10-minute built-in hold (T-minus 20m)
01...00...00...03:45 PM......NASA test director countdown briefing
01...00...00...03:45 PM......Resume countdown (T-minus 20m)

00...59...00...03:46 PM......Backup flight computer to OPS 1
00...55...00...03:50 PM......KSC area clear to launch

00...49...00...03:56 PM......Begin final built-in hold (T-minus 9m)
00...24...00...04:21 PM......NTD launch status verification
00...09...00...04:41:27 PM...Resume countdown (T-minus 9m)

00...07...30...04:42:57 PM...Orbiter access arm retraction
00...05...00...04:45:27 PM...Launch window opens
00...05...00...04:45:27 PM...Hydraulic power system (APU) start
00...04...55...04:45:32 PM...Terminate LO2 replenish
00...04...00...04:46:27 PM...Purge sequence 4 hydraulic test
00...04...00...04:46:27 PM...IMUs to inertial
00...03...55...04:46:32 PM...Aerosurface profile
00...03...30...04:46:57 PM...Main engine steering test
00...02...55...04:47:32 PM...LO2 tank pressurization
00...02...35...04:47:52 PM...Fuel cells to internal reactants
00...02...30...04:47:57 PM...Clear caution-and-warning memory
00...02...00...04:48:27 PM...Crew closes visors
00...01...57...04:48:30 PM...LH2 tank pressurization
00...00...50...04:49:37 PM...SRB joint heater deactivation
00...00...31...04:49:56 PM...Shuttle GPCs take control of countdown
00...00...21...04:50:06 PM...SRB steering test
00...00...07...04:50:20 PM...Main engine start (T-6.6 seconds)
00...00...00...04:50:27 PM...SRB ignition (LAUNCH)