SEQUENCE OF MAJOR EVENTS OF THE CHALLENGER ACCIDENT
Mission Time Elapsed
(GMT, in hr:min:sec) Event Time (secs.) Source
16:37:53.444 ME-3 Ignition Command -6.566 GPC
37:53.564 ME-2 Ignition Command -6.446 GPC
37:53.684 ME-1 Ignition Command -6.326 GPC
38:00.010 SRM Ignition Command (T=0) 0.000 GPC
38:00.018 Holddown Post 2 PIC firing 0.008 E8 Camera
38:00.260 First Continuous Vertical Motion 0.250 E9 Camera
38:00.688 Confirmed smoke above field joint
on RH SRM 0.678 E60 Camera
38:00.846 Eight puffs of smoke (from 0.836
thru 2.500 sec MET) 0.836 E63 Camera
38:02.743 Last positive evidence of smoke
above right aft SRB/ET attach ring 2.733 CZR-1 Camera
38:03.385 Last positive visual indication
of smoke 3.375 E60 Camera
38:04.349 SSME 104% Command 4.339 E41M2076D
38:05.684 RH SRM pressure 11.8 psi above
nominal 5.674 B47P2302C
38:07.734 Roll maneuver initiated 7.724 V90R5301C
38:19.869 SSME 94% Command 19.859 E41M2076D
38:21.134 Roll maneuver completed 21.124 VP0R5301C
38:35.389 SSME 65% Command 35.379 E41M2076D
38:37.000 Roll and Yaw Attitude Response to
Wind (36.990 to 62.990 sec) 36.990 V95H352nC
38:51.870 SSME 104% Command 51.860 E41M2076D
38:58.798 First evidence of flame on RH SRM 58.788 E207 Camera
38:59.010 Reconstructed Max Q (720 psf) 59.000 BET
38:59.272 Continuous well defined plume
on RH SRM 59.262 E207 Camera
38:59.763 Flame from RH SRM in +Z direction
(seen from south side of vehicle) 59.753 E204 Camera
39:00.014 SRM pressure divergence (RH vs. LH) 60.004 B47P2302
39:00.248 First evidence of plume deflection,
intermittent 60.238 E207 Camera
39:00.258 First evidence of SRB plume
attaching to ET ring frame 60.248 E203 Camera
39:00.998 First evidence of plume deflection,
continuous 60.988 E207 Camera
39:01.734 Peak roll rate response to wind 61.724 V90R5301C
39:02.094 Peak TVC response to wind 62.084 B58H1150C
39:02.414 Peak yaw response to wind 62.404 V90R5341C
39:02.494 RH outboard elevon actuator hinge
moment spike 62.484 V58P0966C
39:03.934 RH outboard elevon actuator delta
pressure change 63.924 V58P0966C
39:03.974 Start of planned pitch rate
maneuver 63.964 V90R5321C
39:04.670 Change in anomalous plume shape
(LH2 tank leak near 2058 ring
frame) 64.660 E204 Camera
39:04.715 Bright sustained glow on sides
of ET 64.705 E204 Camera
39:04.947 Start SSME gimbal angle large
pitch variations 64.937 V58H1100A
39:05.174 Beginning of transient motion due
to changes in aero forces due to
plume 65.164 V90R5321C
39:06.774 Start ET LH2 ullage pressure
deviations 66.764 T41P1700C
39:12.214 Start divergent yaw rates
(RH vs. LH SRB) 72.204 V90R2528C
39:12.294 Start divergent pitch rates
(RH vs. LH SRB) 72.284 V90R2525C
39:12.488 SRB major high-rate actuator
command 72.478 V79H2111A
39:12.507 SSME roll gimball rates 5 deg/sec 72.497 V58H1100A
39:12.535 Vehicle max +Y lateral
acceleration (+.227 g) 72.525 V98A1581C
39:12.574 SRB major high-rate actuator
motion 72.564 B58H1151C
39:12.574 Start of H2 tank pressure decrease
with 2 flow control valves open 72.564 T41P1700C
39:12.634 Last state vector downlinked 72.624 Data reduction
39:12.974 Start of sharp MPS LOX inlet
pressure drop 72.964 V41P1330C
39:13.020 Last full computer frame of TDRS
data 73.010 Data reduction
39:13.054 Start of sharp MPS LH2 inlet
pressure drop 73.044 V41P1100C
39:13.055 Vehicle max -Y lateral
accelerarion (-.254 g) 73.045 V98A1581C
39:13.134 Circumferential white pattern on
ET aft dome (LH2 tank failure) 73.124 E204 Camera
39:13.134 RH SRM pressure 19 psi lower
than LH SRM 73.124 B47P2302C
39:13.147 First hint of vapor at intertank E207 Camera
39:13.153 All engine systems start responding
to loss of fuel and LOX inlet
pressure 73.143 SSME team
39:13.172 Sudden cloud a long ET between
intertank and aft dome 73.162 E207 Camera
39:13.201 Flash between Orbiter & LH2 tank 73.191 E204 Camera
39:13.221 SSME telemetry data interference
from 73.211 to 73.303 73.211
39:13.223 Flash near SRB fwd attach and
brightening of flash between
Orbiter and ET 73.213 E204 Camera
39:13.292 First indication intense white
flash at SRB fwd attach point 73.282 E204 Camera
39:13.337 Greatly increased intensity of
white flash 73.327 E204 Camera
39:13.387 Start RCS jet chamber pressure
fluctuations 73.377 V42P1552A
39:13.393 All engines approaching HPFT
discharge temp redline limits 73.383 E41Tn010D
39:13.492 ME-2 HPFT disch. temp Chan. A vote
for shutdown; 2 strikes on Chan. B 73.482 MEC data
39:13.492 ME-2 controller last time word
update 73.482 MEC data
39:13.513 ME-3 in shutdown due to HPFT discharge
temperature redline exceedance 73.503 MEC data
39:13.513 ME-3 controller last time word
update 73.503 MEC data
39:13.533 ME-1 in shutdown due to HPFT discharge
temperature redline exceedance 73.523 Calculation
39:13.553 ME-1 last telemetered data point 73.543 Calculation
39:13.628 Last validated Orbiter telemetry
measurement 73.618 V46P0120A
39:13.641 End of last reconstructured data
frame with valid synchronization
and frame count 73.631 Data reduction
39:14.140 Last radio frequency signal from
Orbiter 74.130 Data reduction
39:14.597 Bright flash in vicinity of Orbiter
nose 74.587 E204 Camera
39:16.447 RH SRB nose cap sep/chute
deployment 76.437 E207 Camera
39:50.260 RH SRB RSS destruct 110.250 E202 Camera
39:50.262 LH SRB RSS destruct 110.252 E230 Camera
ACT POS -- Actuator Position
APU -- Auxilixary Power Unit
BET -- Best Estimated Trajectory
CH -- Channel
DISC -- Discharge
ET -- External Tank
GG -- Gas Generator
GPC -- General Purpose Computer
GMT -- Greenwich Mean Time
HPFT -- High Pressure Fuel Turbopump
LH -- Lefthand
LH2 -- Liquid Hydrogen
LO2 -- Liquid Oxygen (same as LOX)
MAX Q -- Maximum Dynamic Pressure
ME -- Main Engine (same as SSME)
MEC -- Main Engine Controller
MET -- Mission Elapsed Time
MPS -- Main Propulsion System
PC -- Chamber Pressure
PIC -- Pyrotechnics Initiator Controller
psf -- Pounds per square foot
RCS -- Reaction Control System
RGA -- Rate Gyro Assembly
RH -- Righthand
RSS -- Range Safety System
SRM -- Solid Rocket Motor
SSME -- Space Shuttle Main Engine
TEMP -- Temperature
TVC -- Thrust Vector Control
NOTE: The Shuttle coordinate system used is relative to the Orbiter,
as follows:
+X direction = forward (tail to nose)
-X direction = rearward (nose to tail)
+Y direction = right (toward the right wing tip)
-Y direction = left (toward the left wing tip)
+Z direction = down
-Z direction = up
Rogers Commission report table of contents.