1

13:10:39

TIG-5

APU 2 Start - Low Press

1

13:10:39

2

13:15:30

TIG

OMS TIG

2

13:15:30

3

13:18:08

OMS End of Burn

3

13:18:08

4

13:26:09

FRCS Dump Start

4

13:26:09

5

13:27:12

FRCS Dump Complete

5

13:27:12

6

4

13:31:25

EI-13

APU 1 Start - Low Press

6

13:31:25

7

5

13:31:29

APU 3 Start - Low Press

7

13:31:29

8

13:31:57

APU 1 Norm Press

8

13:31:57

9

13:31:59

APU 2 Norm Press

9

13:31:59

10

13:32:01

APU 3 Norm Press

10

13:32:01

11

13:32:29

SSME Engine Stow sequence start

Sequence was completed with closure of TVC Iso Vlv 1 at 13:33:30 GMT.

11

13:32:29

12

13:39:09

EI-5 (304 PRO)

Mach 24.40

V90Q8001C

12

13:39:09

V90Q8001C

nn

13

13:39:11

Speedbrake close & Rudder cmded to zero

13

13:39:11

14

6

13:44:09

EI

Entry Interface (400,000 Ft)

Mach 24.57

14

13:44:09

15

13:46:48

Qbar 0.5 psf

Mach 24.66

15

13:46:48

16

13:47:52

Qbar 2.0 psf

Elevon, BF active

Mach 24.66

16

13:47:52

17

deleted

17

deleted

17.5

13:49:07

ISELECT = 2

Closed-Loop Guidance

17.5

13:49:07

18

13:49:16

Qbar 10 psf

Roll Jets Deactivated

Mach 24.57

18

13:49:16

19

deleted

19

deleted

20

6.3

13:49:32

Initial Roll

Mach 24.51

V90H1044C

20

13:49:32

V90H1044C

nn

20.3

6.5

13:50:00 / 43

Five events of unexpected Return link comm drop-out.
Event 1 - 13:50:00 (1 sec); Event 2 - 13:50:04 / 06; Event 3 - 13:50:16/22: Event 4 - 13:50:25/28; Event 5 - 13:50:42 (1 sec)

On upper left aft antenna (TDRS 171/W). S-Band comm drop-outs considered out-of-family based on comparison with previous 102 flight data at 39 degrees, into KSC, descending node and similar look angles to TDRS.

20.3

13:50:00 / 43

20.5

13:50:30

1st Entry Heating Indication

Nominal Rise in Center Line Bond Temp (1) due to Entry Heating

Aft fuselage center bottom bond line

V09T1702A

20.5

13:50:30

V09T1702A

1140

-108

309

1

1.46

-75 / +300

21

7

13:50:53

Start of Peak Heating

Determined by analysis

Remote sensors indicate off-nominal external event - earliest known event

Note: L2L jet firing at 13:51:45.38 / 51.45.62. L3L jet firing at 13:51:45.36 / 41.45.60. R2R/R3R jet firings between 13:52:08 / 52:15 during data loss (firings determined by inj temp). R2R/R3R jet firings between 13:52:24 / 52:32 during data loss (firing determined by inj temps). (RCS data taken from Atlas analysis and plotted data).

21.5

13:51:19 / 13:52:49

22

7.35

13:51:46

Inertial sideslip angle (Beta) goes and stays Negative until LOS

While the magnitude of the observed Beta is not outside the flight history (41G & 42), the almost linear negative ramp prior to the first roll reversal is not consistent with other flights reviewed. This is consistent with a negative rolling and yawing torque on the vehicle.

V90H2249C

22

13:51:46

V90H2249C

nn

22.5

7.4

13:52:05

First clear indication of off-nominal aero increments

Delta yawing moment coefficient only (as compared to nominal aero). Derived by analysis.

22.5

13:52:05

22.6

7.45

13:52:09 / 15

Unexpected Return link comm drop-out (Event 6)

On upper left aft antenna (TDRS 171/W). S-Band comm drop-out considered out-of-family based on previous flt data (same remarks as seq # 20.3 above).

22.6

13:52:09 / 15

23

deleted

23

deleted

23.3

13:52:15

2nd Entry Heating Indication

Nominal Rise in Center Line Bond Temps (2) due to Entry Heating

Mid Fus Lower "Mid" Skin Temp
Mid Fus Bottom Center Bond Line Temp X1214

V34T1110A
V34T1112A

23.3

13:52:15

V34T1110A
V34T1112A

nn
nn

24

8

13:52:17

LMG Brake Line Temp D - On wheel well inbd sidewall (aft of sw vlvs) - Start of off nominal trend

Initiation of temp rise - off nominal based on rise rate comparison with flight experience.

V58T1703A

24

13:52:17

V58T1703A

1183

-108

312

1

1.46

-75/+300

24.3

7.45

13:52:25 / 31

Two events of unexpected Return link comm drop-out
Event 7 - 13:52:25/26; Event 8 - 13:52:29/31

On upper left aft antenna (TDRS 171/W). S-Band comm drop-out considered out-of-family based on previous flt data (same remarks as seq # 20.3 above).

24.3

13:52:25 / 31

24.5

deleted

24.5

deleted

24.7

deleted

24.7

deleted

24.8

8.5

13:52:32

Supply H2O dump Nozzle temps A/B show temporary increase in temp rise rate (15 second duration of high rise rate).

High rise rate is bounded by data loss. Increase in rise rate not observed on previous flights. GMT shown indicates start of initial rise duration. Reference event seq no. 26.6 for termination of event.

V62T0440A
V62T0439A

24.8

13:52:32

V62T0440A
V62T0439A

24.9

8.5

13:52:32

Vacuum vent temp shows temporary increase in temp rise rate (23 second duration of high rise rate).

High rise rate is bounded by data loss. Increase in rise rate not observed on previous flights. GMT shown indicates start of initial rise duration. Reference event seq no. 26.65 for termination of event.

V62T0551A

24.9

13:52:32

V62T0551A

25

8

13:52:41

LMG Brake Line Temp A - On strut facing MLG door - start of off nominal trend

Initiation of temp rise - off nominal based on rise rate comparison with flight experience.

V58T1700A

25

13:52:41

V58T1700A

1116

-140.4

282.8

1

1.46

-75/+300

25.5

deleted

25.5

deleted

26

8

13:52:41

Left Main Gear Brake Line Temp C - Start of off nominal trend

Unusual Temp Rise

V58T1702A

26

13:52:41

V58T1702A

1140

-108

309

1

1.46

-75/+300

26.5

deleted

26.5

deleted

26.6

8.5

13:52:47

Supply H2O dump Nozzle temps A/B return to typical rise rates.

High rise rate is bounded by data loss. GMT shown indicates end of initial rise duration. Temp took additional 48 seconds to return to nominal temp rise (53:35 GMT).

V62T0440A
V62T0439A

26.6

13:52:47

V62T0440A
V62T0439A

26.63

7.45

13:52:49 / 55

Unexpected Return link comm drop-out (Comm event 9)

On upper left aft antenna (TDRS 171/W). S-Band comm drop-out considered out-of-family based on previous flt data (same remarks as seq # 20.3 above).

26.63

13:52:49 / 55

26.65

8.5

13:52:55

Vacuum vent temp returns to typical rise rate.

High rise rate is bounded by data loss. GMT shown indicates end of initial rise duration. Temp took additional 40 seconds to returns to nominal temp rise (53:35 GMT).

V62T0551A

26.65

13:52:55

V62T0551A

26.7

13:52:56

Left INBD Elevon Lower Skin Temp - Start of off nominal trend

Temp trending down

V09T1006A

26.7

13:52:56

27

10

13:52:59

Left INBD Elevon Lower Skin Temp - OSL

V09T1006A

27

13:52:59

V09T1006A

nn

1

2.54

-200/+450

27.2

10.5

13:53:01

First clear indication of off-nominal rolling moment increment

Start of steady (-) growth in roll moment, derived by analysis

n/a

27.2

13:53:01

27.5

13:53:02

Hyd Syst 1LH INBD Elevon Actr Ret Ln Temp - start of off nominal trend
Hyd Syst 3 LOE Ret LN Temp - start of off nominal trend

Temp trending down

Temp trending down

V58T0157A

V58T0394A

27.5

13:53:02

V58T0157A

V58T0394A

1350

nn

-219

nn

118

nn

1

1

1.46

nn

-75/+300

nn

28

11

13:53:10

Hyd Syst 3 LOE Ret LN Temp - OSL

OSL was preceded by Nominal Temp rise

V58T0394A

28

13:53:10

V58T0394A

1368

-368

nn

1

1.46

-75/+300

29

11

13:53:11

Hyd Syst 1LH INBD Elevon Actr Ret Ln Temp - OSL

OSL was preceded by Nominal Temp rise

V58T0157A

29

13:53:11

V58T0157A

1350

-219

118

1

1.46

-75/+300

29.3

11.1

13:53:24

Alpha Modulation

Angle of attack modulation active

V90H0803C

29.3

13:53:24

V90H0803C

nn

29.5

11.2

13:53:26

Approx Veh Grd Location:
38.7 N / -123.5 W

Altitude 231600 ft / Mach 23.0 - Crossing the California Coastline

Data source: STS-107 GPS Trajectory Data

29.5

13:53:26

30

11

13:53:31 / 53:34

Hyd Syst 1 LOE Return Line Temp - OSL

OSL was preceded by Nom Temp rise plus data loss 3 sec's prior to event

V58T0193A

30

13:53:31 / 53:34

V58T0193A

1377

-367

436

1

1.46

-75/+300

30.2

11.3

13:53:32 / 34

Unexpected Return link comm drop-out (Comm event 10)

On upper left aft antenna (TDRS 171/W). S-Band comm drop-out considered out-of-family based on previous flt data (same remarks as seq # 20.3 above).

30.2

13:53:32 / 34

30.3

13:53:34 / 55:57

3rd Entry Heating Indication

Nominal Rise in Center Line Bond Temps (3) due to Entry Heating

13:53:34 - V09T1016A (Mid Fus Bot Port BL T X 620);
13:54:00 - V09T1022A (Mid Fus Bot Port BL T X 777);
13:55:57 - V09T1624A (Fwd Fus Lwr Skin Bot CL T)

V09T1016A

V09T1022A

V09T1624A

30.3

13:53:34 / 55:57

V09T1016A
V09T1022A
V09T1624A

nn
nn
nn

30.5

13:53:34

Hyd Sys 2 LIE Return Ln Temp - Start of Off Nominal Trend

Temp trending down

V58T0257A

30.5

13:53:34

V58T0257A

nn

31

11

13:53:36

Hyd Sys 2 LIE Return Ln Temp - OSL

V58T0257A

31

13:53:36

V58T0257A

1348

-219

116

1

1.46

-75/+300

31.5

deleted

31.5

deleted

31.7

deleted

31.7

deleted

32

deleted

32

deleted

32.1

11.5

13:53:44 / 48

Debris #1 - First report of debris observed leaving the Orbiter

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0064
EOC2-4-0056

32.1

13:53:44 / 48

32.3

11.5

13:53:46 / 50

Debris #2 - Second report of debris observed leaving the Orbiter

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0064
EOC2-4-0056

32.3

13:53:46 / 50

32.5

13:53:46

LMG Brake Line Temp A - On strut facing MLG door - Start of off nominal trend (temp rise rate change)

Temp rise rate change from 1.4 F/min to 5.5 F/min and increasing to LOS

V58T1700A

32.5

13:53:46

V58T1700A

1116

-140.4

282.8

1

1.46

-75/+300

32.7

11.5

13:53:54 / 58

Debris #3 - Third report of debris observed leaving the Orbiter. Event followed by momentary brightening of plasma trail.

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

Debris:
EOC2-4-0056, 0026
Trail:
EOC2-4-0064, 0056

32.7

13:53:54 / 58

32.8

11.5

13:54:00 / 04

Debris #4 - Fourth report of debris observed leaving the Orbiter

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0056
EOC2-4-0026

32.8

13:54:00 / 04

32.9

11.5

13:54:07 / 11

Debris #5 - Fifth report of debris observed leaving the Orbiter

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0056
EOC2-4-0026

32.9

13:54:07 / 11

33

13

13:54:10

LMG Brake Line Temp B - Start of off nominal trend

Temp Increase

V58T1701A

33

13:54:10

V58T1701A

1116

-139.6

282.8

1

1.46

-75/+300

33.5

11.3

13:54:14 / 22

Unexpected Return link comm drop-out (Comm event 11)

On upper left aft antenna (TDRS 171/W). S-Band comm drop-out considered out-of-family based on previous flt data (same remarks as seq # 20.3 above).

33.5

13:54:14 / 22

34

14

13:54:20

Start of slow aileron trim change

GMT is approximate (13:54:20 +/- 10 seconds)

V90H1500C

34

13:54:20

V90H1500C

nn

34.5

14

13:54:20

Reversal in growth trend of derived roll moment coefficient

Observed moment changed from a negative slope to positive slope. Derived by analysis.

n/a

34.5

13:54:20

35

15

13:54:22

M-FUS LT BL Temp at x1215 - start of off nominal trend (increased rise rate)

Unusual Temp Rise (Rise rate higher than STS-109 & 87). Rise rate increased from 1 F/min (typical) to 7.6 F/min.

V34T1106A

35

13:54:22

V34T1106A

1215

nn

1

nn

35.2

15

13:54:22

LH Aft Fus Sidewall Temp at x1410 - start of off nominal trend (increased rise rate)

Unusual Temp Rise (Rise rate higher than STS-109 & 87). Rise rate increased from 2.7 F/min (typical) to 5.5 F/min.

V09T1724A

35.2

13:54:22

V09T1724A

1410

nn

35.5

13

13:54:24

Sys 3 Left Main Gear Strut Actuator Temp - start of off nominal trend

Unusual Temp Rise

V58T0405A

35.5

13:54:24

V58T0405A

1183

-115

315

1

1.46

-75/+300

35.7

13:54:25

Approx Veh Grd Location:
38.3 N / -119.0 W

Altitude 227400 ft / Mach 22.5 - Crossing the California / Nevada State Line

Data source: STS-107 GPS Trajectory Data

35.7

13:54:25

35.8

13:54:26

S-Band switched from upper left aft antenna to upper right aft antenna

TDRS 171/W

35.8

13:54:26

36

deleted

36

deleted

36.5

15.3

13:54:33.3 / 33.9

Flash #1 - Orbiter envelope suddenly brightened (duration 0.3 sec), leaving noticeably luminescent signature in plasma trail

Note: R3R and R2R 0.24 sec jet firings occurred at 13:54:33.52 / 33.76 and 13:54:33.54 / 33.78 respectively (ref: RCS Atlas analysis and plots).

EOC2-4-0026
EOC2-4-0034
EOC2-4-0009B

36.5

13:54:33.3 / 33.9

36.6

15.3

13:54:35 / 37

Debris #6 - Very bright debris seen leaving the Orbiter

Seen just aft of Orbiter envelope. Also, reference RCS jet firing note in item # 36.5 above. Debris events 6 and 14 are visually the biggest, brightest events and therefore may indicate the most significant changes to the Orbiter of the western debris events.

EOC2-4-0026
EOC2-4-0009B
EOC2-4-0030

36.6

13:54:35 / 37

37

deleted

37

deleted

37.5

deleted

37.5

deleted

37.7

13:54:53

MLG LH Outbd Wheel Temp - start of off nominal trend

2 bit flips up (ref #56.5 when temp starts to trend down)

V51T0574A

37.7

13:54:53

V51T0574A

1074

-115

nn

1

0.98

-75/+300

37.75

15.35

13:55:04 / 10

Debris #7 - Seventh report of debris observed leaving the Orbiter

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0030

37.75

13:55:04 / 10

37.8

13

13:55:12

Sys 3 LMG Brake Sw Vlv Ret Line Temp (FWD) - start of off nominal trend

Temp Increase

V58T0842A

37.8

13:55:12

V58T0842A

1156

-110

314

1

1.46

-75/+300

38

deleted

38

deleted

39

deleted

39

deleted

40

13:55:21

Drag 11 fps2

Drag Measurement Incorporation

Mach 21.nn

40

13:55:21

40.1

15.35

13:55:21 / 27

Debris #8 - Eighth report of debris observed leaving the Orbiter. Event was followed by momentary brightening of plasma trail.

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

Debris: EOC2-4-0030; trail: EOC2-4-0005, 0017, 0021, 0028, and 0030

40.1

13:55:21 / 27

40.2

15.35

13:55:25 / 29

Debris #9 - Ninth report of debris observed leaving the Orbiter. Event was followed by multiple secondary plasma trails.

Seen just aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0030, 0050

40.2

13:55:25 / 29

40.3

15.35

13:55:26 / 30

Debris #10 - Tenth report of debris observed leaving the Orbiter

Seen well aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0005

40.3

13:55:26 / 30

40.4

15.4

13:55:30

Remote sensors indicate off-nominal external event

GMT is approximate. Preliminary match to debris shedding seen in video from Ivins, UT (Debris #10). Strong confidence that this is an off-nominal event. No evidence of RCS jet firings (ref Atlas data and plots).

40.4

13:55:30

40.5

13:55:32

Approx Veh Grd Location:
37.4 N / -114.1 W

Altitude 223400 ft / Mach 21.8 - Crossing the Nevada / Utah State Line

Data source: STS-107 GPS Trajectory Data

40.5

13:55:32

40.6

13:55:33 / 35

Return link comm drop-out (Comm event 12)

First comm drop out after switched to upper right aft antenna (TDRS 171/W). While uncommon to have a drop out at this point, inconclusive if drop-out is off-nominal based on previous flt data.

40.6

13:55:33 / 35

41

deleted

41

deleted

41.5

15.45

13:55:36 / 42

Debris #11 - Eleventh report of debris observed leaving the Orbiter

Seen well aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0050

41.5

13:55:36 / 42

42

15.5

13:55:41

Mid Fus Port (Left) Sill Longn Temp at x1215 - start of off nominal trend

Unusually high temp rise with respect to STS-87 & 109. Went to 2.6 F/min from 0 F/min.

V34T1118A

42

13:55:41

V34T1118A

nn

42.3

15.45

13:55:45 / 49

Debris #12 - Twelfth report of debris observed leaving the Orbiter. Event was preceded and followed by secondary plasma trails.

Seen aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0028, 0050

42.3

13:55:45 / 49

42.5

13:55:55

Approx Veh Grd Location:
37.0 N / -112.4 W

Altitude 222100 ft / Mach 21.5 - Crossing the Utah / Arizona State Line

Data source: STS-107 GPS Trajectory Data

42.5

13:55:55

42.7

15.45

13:55:55 / 59

Debris #13 - Thirteenth report of debris observed leaving the Orbiter. Event was followed by momentary brightening of plasma trail adjacent to debris.

Seen well aft of Orbiter envelope. No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0005, 0017, 0021

42.7

13:55:55 / 59

42.8

15.45

13:55:58 / 56:00

Debris #14 - Very bright debris observed leaving the Orbiter.

Seen just aft of Orbiter envelope. Debris events 6 and 14 are visually the biggest, brightest events and therefore may indicate the most significant changes to the Orbiter of the western debris events.- No evidence of RCS jet firings (ref Atlas data and plots).

EOC2-4-0005, 0017, 0021, 0028, 0030

42.8

13:55:58 / 56:00

42.9

13:56:00 / 03

Return link comm drop-out (Comm event 13)

On upper right aft antenna (TDRS 171/W). While uncommon to have a drop out at this point, inconclusive if drop-out is off-nominal based on previous flt data.

42.9

13:56:00 / 03

43

13:56:02

Qbar 40 psf

Aft RCS Pitch Jets Deactivated

43

13:56:02

44

16

13:56:03

Left Lower Wing Skin Temp - start of off nominal trend

Temp reading trending down (potential sensor/wire damage)

V09T1002A

44

13:56:03

V09T1002A

1280.1

240

LWR

1

2.54

-200/+450

44.2

15.45

13:56:09 / 13

Debris #15 - Fifteenth report of debris observed leaving the Orbiter.

Seen just aft of Orbiter envelope. Nearest jet firings: R2R jet firing at 032:13:56:17.30 / 56:17.54 for 0.24 seconds, & R3R jet firing at 032:13:56:17.28 / 56:17.52 for 0.24 seconds. (Ref: RCS Atlas data analysis and plots).

EOC2-4-0017

44.2

13:56:09 / 13

44.5

16.5

13:56:16

Hyd Sys 1 LMG UpLK Actr Unlk Ln Temp - Temp rise rate change

Temp rise rate change from 0.7 F/min (nominal) to 3.9F/min and increasing to LOS

V58T0125A

44.5

13:56:16

V58T0125A

1159

-124

315

1

1.46

-75/+300

44.6

16.5

13:56:17

Sys 3 LMG Brake Sw Vlv Ret Line Temp (FWD) - Temp rise rate change

Temp rise rate change from 1.5 F/min to 8.8 F/min (stayed at this rate to LOS)

V58T0842A

44.6

13:56:17

V58T0842A

1156

-110

314

1

1.46

-75/+300

44.7

16.5

13:56:20

LMG Brake Line Temp C - Temp rise rate change

Temp rise rate change from 1.3 F/min to 9.9 F/min (stayed at this rate to LOS)

V58T1702A

44.7

13:56:20

V58T1702A

1140

-108

309

1

1.46

-75/+300

44.8

16.5

13:56:22

LMG Brake Line Temp B - Temp rise rate change

Temp rise rate change from 2.1 F/min to 9.1 F/min increasing to LOS

V58T1701A

44.8

13:56:22

V58T1701A

1116

-139.6

282.8

1

1.46

-75/+300

45

16

13:56:24

Left Upper Wing Skin Temp - start of off nominal trend

Temp reading trending down (potential sensor/wire damage)

V09T1024A

45

13:56:24

V09T1024A

1280.1

240

UPR

1

2.54

-200/+450

46

16.55

13:56:30

1st Roll Reversal Initiation

Mach 21.13

V90H1044C

46

13:56:30

V90H1044C

nn

46.5

13:56:45

Approx Veh Grd Location:
36.1 N / -109.0 W

Altitude 219000 ft / Mach 20.9 - Crossing the Arizona / New Mexico State Line

Data source: STS-107 GPS Trajectory Data

46.5

13:56:45

46.7

16.5

13:56:53

Sys 3 Left Main Gear Strut Actuator Temp - Temp rise rate change

Temp rise rate change from 1.7 F/min to 12.9 F/min (stayed at this rate to LOS)

V58T0405A

46.7

13:56:53

V58T0405A

1183

-115

315

1

1.46

-75/+300

47

16.55

13:56:55

Roll Reversal #1

1st Roll Reversal Complete

Mach 20.76

V90H1044C

47

13:56:55

V90H1044C

nn

47.5

13:56:55 / 57

Return link comm drop-out (Comm event 14)

On upper right aft antenna (TDRS 171/W). While uncommon to have a drop out at this point, inconclusive if drop-out is off-nominal based on previous flt data.

47.5

13:56:55 / 57

Note: No further comm drop-out events are listed in the timeline thru LOS, since they are not considered out-of-family at this time.

48

13:56:58

IMU Velocity Increase

Reflects accelerations imparted during roll reversal. Same signature observed on STS-109. Nominal event.

48

13:56:58

49

13:57:nn

Bodyflap deflection up 3 degrees

Matches nominal aero simulation

V90H6410C

49

13:57:nn

V57HxxxxC

nn

49.5

deleted

49.5

deleted

49.55

16.8

13:57:19 / 29

Debris # 16 - Very faint debris observed leaving just aft of Orbiter (occurred over NM)

Observations by personnel from the Starfire Optical Range (Kirtland Air Force Base, NM).
Note: nearest jet firings: L2L jet firing at 032:13:56:54.71 / 57:01.12 & 032:13:57:46.35 / 57:53.12 & L3L jet firing at 032:13:56:54.66 / 57:01.07 & 032:13:57:46.33 / 57:53.10 (all 4 occurred during data dropouts & were determined based on injector temps alone). Also, R2R at 032:13:57:43.94 / 57:44.42 & R3R at 032:13:57:43.92 / 57:44.40 for 0.48 secs ea. (Ref Atlas data analysis and plots.)

EOC2-4-0148-2

49.55

13:57:19 / 29

49.6

16.9

13:57:19

MLG LH Outbd Tire Pressure 1 - start of off nominal trend

Bit flip up - off nominal thru comparison with previous flights

V51P0570A

49.6

13:57:19

V51P0570A

1074

-160

nn

1

0.67

230 / 401

49.7

16.9

13:57:24

MLG LH Outbd Tire Pressure 2 - start of off nominal trend

Bit flip up - off nominal thru comparison with previous flights

V51P0572A

49.7

13:57:24

V51P0572A

1074

-160

nn

1

0.67

230 / 401

50

17

13:57:28

Left Lower Wing Skin Temp - OSL

V09T1002A

50

13:57:28

V09T1002A

1280.1

240

LWR

1

2.54

-200/+450

51

deleted

Rationale for deletion: Originally indicated as "Start of Roll trim in elevons". Inserted independently early in the investigation, but is better defined by sequence no. 54. "Roll trim" is better indicated with aileron trim.

51

deleted

52

17

13:57:43

Left Upper Wing Skin Temp - OSL

V09T1024A

52

13:57:43

V09T1024A

1280.1

240

UPR

1

2.54

-200/+450

53

19

13:57:54

Sys 2 LH Brake Switching Vlv Return Temp (AFT) - start of off nominal trend

Temp increase

V58T0841A

53

13:57:54

V58T0841A

1173

-107

313

1

1.46

-75/+300

53.5

16.8

13:57:53.7 / 55.7

Flare 1: Asymmetrical brightening of Orbiter shape observed (occurred over NM)

Observations by personnel from the Starfire Optical Range (Kirtland Air Force Base, NM).
Note: nearest jet firings: Same as seq no. 49.55 plus L2L at 032:13:58:00.50 / 01.46 & L3L at 032:13:58:00.48 / 01.44 (in both cases there was no start up data, but good tail off/shutdown) - 0.96 sec pulse each. Also, R2R at 032:13:58:03.18 / 09.16 & R3R at 032:13:58:03.18 / 09.16 - (in both cases firings occurred during data dropouts and were determined by injector temps). (Ref Atlas analysis and plots.)

EOC2-4-0148-4

53.5

13:57:53.7 / 55.7

53.7

16.8

13:57:59.5 / 58:01.5

Flare 2: Asymmetrical brightening of Orbiter shape observed (occurred over NM)

Observations by personnel from the Starfire Optical Range (Kirtland Air Force Base, NM).
Note: same jet firing information as for event seq no.s 49.55 & 53.5. (Ref Atlas analysis and plots.)

EOC2-4-0148-4

53.7

13:57:59.5 / 58:01.5

54

20

13:58:03

Start of "sharp" aileron trim increase

Mach 19.79; GMT is approximate (13:58:03+/-10 seconds)

V90H1500C

54

13:58:03

V90H1500C

nn

54.3

20.5

13:58:09

Increase in derived rolling and yawing moment increments

Sustantial increase in observed growth rate of both roll and yaw moment increments. Derived by analysis.

n/a

54.3

13:58:09

54.5

22.5

13:58:16

LMG Brake Line Temp D - Temp rise rate change

Temp rise rate change from 0.9 F/min to 11.7 F/min (stayed at this rate to LOS)

V58T1703A

54.5

13:58:16

V58T1703A

1183

-108

312

1

1.46

-75/+300

55

deleted

55

deleted

55.5

13:58:20

Approx Veh Grd Location:
34.2 N / -103.1 W

Altitude 209800 ft / Mach 19.5 - Crossing the New Mexico / Texas State Line

Data source: STS-107 GPS Trajectory Data

55.5

13:58:20

56

deleted

56

deleted

57

23

13:58:32

MLG LH Outbd Tire Pressure 1 - pressure trending down (to OSL)

Trending to OSL following 7 sec LOS (initiation time not exact) - ref #60

V51P0570A

57

13:58:32

V51P0570A

1074

-160

nn

1

0.67

230 / 401

58

23

13:58:32

MLG LH Inbd Tire Pressure 1 - pressure trending down (to OSL)

Trending to OSL following 7 sec LOS (initiation time not exact) - ref #64

V51P0571A

58

13:58:32

V51P0571A

1074

-115

nn

1

0.67

230 / 401

58.5

13:58:32

MLG LH Outbd Wheel Temp - temperature trending down (to OSL)

Trending to OSL following 7 sec LOS (initiation time not exact) - ref #62

V51T0574A

58.5

13:58:32

V51T0574A

1074

-160

nn

1

0.67

230 / 401

58.7

13:58:32 / 59:22

Sys 2 LH Brake Switching Vlv Return Temp (AFT) - temp rise rate change

Temp rise rate change from 2.5 F/min to 40.0 F/min until 13:59:22 (temp peak) - ref #70.5

V58T0841A

58.7

13:58:32 / 59:22

V58T0841A

59

13:58:36

MLG LH Inbd Wheel Temp - start of temperature trending down (to OSL)

Start of trend to OSL - ref #66

V51T0575A

59

13:58:36

V51T0575A

1074

-115

nn

1

0.98

-75 / +175

60

23

13:58:38

MLG LH Outbd Tire Pressure 1 - OSL

V51P0570A

60

13:58:38

V51P0570A

1074

-160

nn

1

0.67

230 / 401

61

deleted

Rationale for deletion: Moved to seq no. 63.5 after further data review.

61

deleted

62

25

13:58:39

MLG LH Outbd Wheel Temp - OSL

V51T0574A

62

13:58:39

V51T0574A

1074

-115

nn

1

0.98

-75 / +175

63

23

13:58:39

MLG LH Outbd Tire Pressure 2 - start of pressure trending down (to OSL)

Start of trend to OSL - ref #68

V51P0572A

63

13:58:39

V51P0572A

1074

-160

nn

1

0.67

230 / 401

63.5

25.5

13:58:40

BFS Fault Msg (4) - Tire Pressures - First Message

32/13:58:39.94 - SM0 Tire P LOB
32/13:58:41.84 - SM0 Tire P LIB
32/13:58:49.54 - SM0 Tire P LIB
32/13:58:56.26 - SM0 Tire P LOB

63.5

13:58:40

64

23

13:58:40

MLG LH Inbd Tire Pressure 1 - OSL

V51P0571A

64

13:58:40

V51P0571A

1074

-115

nn

1

0.67

230 / 401

65

13:58:41

MLG LH Inbd Tire Pressure 2 - start of off nominal trend

Press rose ~3.5 psia in 2 sec's

V51P0573A

65

13:58:41

V51P0573A

nn

1

0.67

230 / 401

65.5

23

13:58:43

MLG LH Inbd Tire Pressure 2 - start of pressure trending down

V51P0573A

65.5

13:58:43

V51P0573A

nn

0.67

230 / 401

66

25

13:58:48

MLG LH Inbd Wheel Temp - OSL

V51T0575A

66

13:58:48

V51T0575A

nn

1

0.67

230 / 401

67

23

13:58:48

MLG Inbd Tire Pressure 2 - OSL

V51P0573A

67

13:58:48

V51P0573A

nn

1

0.67

230 / 401

68

23

13:58:54

MLG LH Outbd Tire Pressure 2 - OSL

V51P0572A

68

13:58:54

V51P0572A

1074

-160

nn

1

0.67

230 / 401

69

26

13:58:56

BFS Fault Msg (4) - Tire Pressures - Last Message

69

13:58:56

70

27

13:59:06

Left Main Gear Downlocked Indication - Transferred ON

Uplock indicated no change

V51X0125E

70

13:59:06

V51X0125E

1189

-135

nn

1

n/a

0 / 1

70.3

27.5

13:59:23

Loss of MCC real-time data to the workstations in the FCR and MER

70.3

13:59:23

70.5

13:59:22

Sys 2 LH Brake Switching Vlv Return Temp (AFT) - start of sharp downward temperature trend

Temp trending down until loss of signal - ref #81

V58T0841A

70.5

13:59:22

V58T0841A

1173

-107

313

1

1.46

-75/+300

71

28

13:59:30.66

Start of R2R yaw firing

Last pulse before LOS (stayed on to end of first 5-sec period of recon data at 032/13:59:37.4 GMT)

V79X2634X

71

13:59:30.66

V79X2634X

nn

n/a

0 / 1

72

28

13:59:30.68

Start of R3R yaw firing

Last pulse before LOS (stayed on to end of first 5-sec period of recon data at 032/13:59:37.4 GMT)

V79X2638X

72

13:59:30.68

V79X2638X

nn

n/a

0 / 1

73

29

13:59:31

Observed elevons deflection at LOS

Left: -8.11 deg (up); Right: -1.15 deg (up)

V90H7505C
V90H7555C

73

13:59:31

73.1

29.3

13:59:31.400

FCS Channel 4 Aerosurface position measurements start trending towards their null values

Indicates worsening failure of transducer excitation via a wiring short conditions

V57H0253A
(5 Hz)

73.1

13:59:31.400

73.2

29.3

13:59:31.478

All FCS Channel 4 Bypass valves close (indicating bypassed)

Leading indicator of ASA fail (high-rate data)

V58P0915A

73.2

13:59:31.478

73.3

29.3

13:59:31.7

Speedbrake channel 4 OI position measurement indicated successively 19, 20, 24 degrees over last three samples prior to LOS (should be closed / 0º).

Speedbrake was commanded to "overclose" (-10 degrees), position measurements for Channels 1 thru 3 were 0 degrees. Secondary delta pressure on Ch 4 went to zero, which indicates that the channel was bypassed. This is real data and the ASAs were responding appropriately.

V57H0253A
(5 Hz)

73.3

13:59:31.7

V57H0253A

nn

5

nn

73.5

29.5

13:59:32

Observed aileron trim at LOS

Trim: -2.3 deg (V96H2045C - V90H1500C)

73.5

13:59:32

74

13:59:32

M-FUS LT BL Temp at x1215 - LOS

LOS

V34T1106A

74

13:59:32

V34T1106A

1215

nn

1

nn

74.5

13:59:32

LH Aft Fus Sidewall Temp at x1410 - LOS

LOS

V09T1724A

74.5

13:59:32

V09T1724A

1410

nn

75

13:59:32

LMG Brake Line Temp A - LOS

LOS at 172.2 F

V58T1700A

75

13:59:32

V58T1700A

1116

-140.4

282.8

1

1.46

-75/+300

76

13:59:32

LMG Brake Line Temp B - LOS

LOS at 154.2 F

V58T1701A

76

13:59:32

V58T1701A

1116

-139.6

282.8

1

1.46

-75/+300

77

13:59:32

LMG Brake Line Temp C - LOS

LOS at 104.8 F

V58T1702A

77

13:59:32

V58T1702A

1140

-108

309

1

1.46

-75/+300

78

13:59:32

LMG Brake Line Temp D - LOS

LOS at 88.3 F

V58T1703A

78

13:59:32

V58T1703A

1183

-108

312

1

1.46

-75/+300

79

13:59:32

Left Main Gear Strut Actuator Temp - LOS

LOS at 76.3 F

V58T0405A

79

13:59:32

V58T0405A

1183

-115

315

1

1.46

-75/+300

80

13:59:32

Hyd Sys 1 LMG Uplk Actr Unlk Ln Temp - LOS

LOS at 52.2 F

V58T0125A

80

13:59:32

V58T0125A

1159

-124

315

1

1.46

-75/+300

81

13:59:32

Sys 2 LH Brake Sw Vlv Return Temp (AFT) - LOS

LOS at 62.8 F

V58T0841A

81

13:59:32

V58T0841A

1173

-107

313

1

1.46

-75/+300

82

13:59:32

Sys 3 LMG Brake Sw Vlv Return Line Temp (FWD) - LOS

LOS at 67.3 F

V58T0842A

82

13:59:32

V58T0842A

1156

-110

314

1

1.46

-75/+300

82.5

deleted

82.5

deleted

82.7

32.5

31:59:32

Approx Veh Grd Location:
32.9 N / -99.0 W

Altitude ~200700 ft / Mach ~18.1 - Near Dallas TX

Approximate Vehicle Ground Location at Loss of Signal based on GMT; Data source: STS-107 GPS Trajectory Data

82.7

31:59:32

82.8

29.3

13:59:32.130

FCS Channel 4 fail flags raised (1 Hz) on all aerosurface actuators

Lagging indicator of ASA position measurement discrepancy

V79X3263X
V79X3268X
V79X3273X
V79X3278X
V79X3334X
V79X3339X

82.8

13:59:32.130

83

33

13:59:32.136

LOS
(Loss of Signal)

Last valid downlink frame accepted by ODRC - OI / BFS / PASS
(This time has been referred to as "LOS" thoughout the investigation.)
Start of reconstructed data

Upper Right Aft (URA) Quad Antenna was selected by BFS antenna management S/W to communicate with TDRS-W. The pointing angle to TDRS-W was off the Orb tail at -65 degs and trending further into blockage. Prev experience / eng calcs predict probable loss of comm at elevation angles greater than -60 degrees. Loss of comm at this GMT is therefore considered nominal.

83

13:59:32.136

84

29.3

13:59:32.195

ASA 4 RPC A&C Trip Indication

Lagging indicator of ASA transducer excitation short condition

V79X4210E
V76X4211E

84

13:59:32.195

85

deleted

Rationale for deletion: moved to 85.6 after further data review.

85

deleted

85.5

29.3

13:59:32.598

Left Outboard bypass valve reopens. A force fight between channels 1/2/3 and channel 4 begins, resulting in a difference of up to 0.5 degrees observed between the left outboard and inboard elevons

Indicates a short in bypass valve has grown sufficient to drop below voltage threshold of valve; RPC B is current limiting.

V58P0865A

85.5

13:59:32.598

85.6

29.3

13:59:33.680

BFS Fault Message annunciation (1) - FCS CH 4

TDRS-E Data. Error is detected by ATVC/ASA hardware when sensed delta pressure across actuator exceeds a limit indicating the FCS channel is no longer driving the actuator. FCS CH 4 failure will annunicate for any of the following: LIB / LOB / RIB / ROB elevon actutor 4, rudder actuator 4, speedbrake actuator 4, SSME 1/2/3 P/Y Actuator D, & L/R SRB R/T actuator D.

85.6

13:59:33.680

86

29.3

13:59:33.863

PASS Fault Message annunciation (1) - FCS CH 4

TDRS-E Data

86

13:59:33.863

87

13:59:33.976

Master Alarm noted.

D&C analysis is continuing to determine cause of alarm.

87

13:59:33.976

88

29.3

13:59:34.518

Left Outboard force fight ends, driver currents go to zero.
(RPC B trip indication).

Leading indicator of RPC B trip / ASA power down. I.e., indicates opening of all bypass valves (due to RPC B trip removing power) on ASA 4. Force fight goes away since actuators are already at the last commanded position (so channel 4 has no hyd load on the servo asking for position change).

V58P0865A

88

13:59:34.518

89

29.3

13:59:34.561

Speedbrake force fight begins (continues to LOS)

Indicates opening of all bypass valves (due to RPC B trip removing power) on ASA 4. Since the speedbrake is at zero but is being commanded to "over-close" position (-10) this results in a force fight between channels 1,2,3 and channel 4.

V57P0260A
V57P0261A
V57P0262A

89

13:59:34.561

90

35

13:59:35/36

Sideslip on vehicle changes sign.

The event occurred between the two times listed. Just prior to initial LOS the magnitude of the negative Sideslip started to decrease and between 59:34 and 59:37 sideslip grew from -.6 to +.8 deg. With this change, the normal roll and yaw moments on the vehicle would change sign. Aerodynamic forces due to sideslip are now reinforcing aerodynamic asymmetry.

90

13:59:35/36

91

36

13:59:36

Growth in Bank attitude error

Up until this time the flight control had been able to maintain the Bank error around 5 deg. Aerojet DAP drops left wing to compensate for increasing aerodymanic moments, creating a bank attitude error.

91

13:59:36

92

37

13:59:36.8

Aerojet DAP Requests Third Right Yaw RCS Jet (R4R)

This additional jet is required to counteract the increasing aerodynamic moments on the vehicle. The RCS jet fired, as expected and stayed on to end of first 5-sec period of recon data at 032/13:59:37.4 GMT.

92

13:59:36.8

93

38

13:59:37.3

Aerojet DAP Requests Fourth Right Yaw RCS Jet (R1R)

This additional jet is required to counteract the increasing aerodynamic moments on the vehicle. The RCS jet fired, as expected and stayed on to end of first 5-sec period of recon data at 032/13:59:37.4 GMT.

93

13:59:37.3

94

39

13:59:37.n

Last aileron data

The aileron position is now approx -5.2 deg with approx -2.5 deg of aileron trim. The rate of change of aileron trim had reached the maximum allowed by the flight control system.

94

13:59:37.n

95

40

13:59:37.396

End of 5 second period of reconstructed data

End of first 5-seconds of the 32-second period of post-LOS data. Start of approximately 25 seconds of no data available

GMT derived by MER data personnel

95

13:59:37.396

96

41

13:59:46.347

PASS Fault Message annunciation - ROLL REF

Message retrieved from "fault message buffer" received between 14:00:04 and 14:00:05. The ROLL REF message is triggered when Roll command req'd to fly reference profiile falls below 37 degs. Message generation less than 10 secs (5 guidance cycles) after start of 4 yaw jets firing suggests rapid change in Lift to Drag ratio.

96

13:59:46.347

Note: BFS does not have this message in the Fault message stack. It is likely that BFS annunciated this message during the 25 second gap of no data, but that if it was annunciated it was pushed out of the downlist stack by additional fault messages (at least 5) annunciated during the gap.

97

41

13:59:52.114

PASS Fault Message annunciation - L RCS LEAK

Data located in PASS fault message buffer. Data is potentially error prone.

97

13:59:52.114

98

41

14:00:01.540*

BFS Fault Message annunciation - L RCS LEAK

Data located in BFS fault message buffer. Data is potentially error prone.
*Time info corrupted.

98

14:00:01.540*

99

41

14:00:01.900*

BFS Fault Message annunciation - L RCS LEAK

Data located in BFS fault message buffer. Data is potentially error prone.
*Time info corrupted.

99

14:00:01.900*

100

42

14:00:02/06

Debris A observed leaving the Orbiter - Large debris seen falling away from the Orbiter envelope.

EOC2-4-0024
EOC2-4-0018
EOC2-4-0118

100

14:00:02/06

101

43

14:00:02.654

PASS Fault Message annunciation - L RCS LJET

Data is potentially error prone.

101

14:00:02.654

102

44

14:00:02.660

Beginning of 2 second period of reconstructed data

Start of last 2-seconds of the 32 second period of post-LOS data.

GMT derived by MER data personnel.

102

14:00:02.660

CAUTION: Data from this period is suspect because multiple bit errors were evident in this reconstructed data. Many of the parameters were 1 Hz data and therefore only one data sample was available. Where possible, high rate data and/or corroborating data were used to draw subsystem performance conclusions. However, some of the conclusions drawn below may be in error or misinterpreted.

During this final 2 second period of reconstructed data, the data indicates the following systems were nominal: APUs were running and WSB cooling was evident (although potentially overcooling). MPS integrity was still evident. Fuel cells were generating power and the PRSD tanks/lines were intact. Comm and navaids systems in the forward fuselage were performing nominally. RSB, Body Flap, main engine, and right wing temps appeared active. With the exception of an apparent FES shutdown, ECLSS performance was nominal.

During this final 2 second period of reconstructed data, the data indicates the following systems were off-nominal: All three Hyd systems were lost (zero pressure/zero rsvr qty's). The left inbd/outbd elevon actuator temps were either OSL or no data exists. WSB's appeared to be overcooling APU lube oil. The FES appeared to have shutdown. Majority of left OMS pod sensors were either OSH or OSL or no data exists. Multiple BFS and PASS fault message annunciations for left pod hardware were found in the buffer. Elevated temps at bottom bondline centerline skin forward and aft of the wheel wells and at the port side structure over left wing were observed. EPDC shows general upward shift in Main Bus amps and downward shift in Main Bus volts. AC3 phase A inverter appeared disconnected from the AC Buss.

GNC data suggests vehicle was in an uncommanded attitude and was exhibiting uncontrolled rates. Yaw rate was at the sensor maximum of 20 deg/sec. The flight control mode was in AUTO. (Note that all Nav-derived parameters (e.g., alpha) are suspect due to high rates corrupting the IMU state.)

Based on the nominal and off-nominal system performance described above, it appears that the fwd/mid/aft fuselage, right wing, and right pod were still intact.

103

45

14:00:03.470*

BFS Fault Message annunciation - L OMS TK P

Data located in BFS fault message buffer after acquisition of data. Data is potentially error prone. *Time info corrupted.
Note: Error is annunciated when left OMS oxidizer tank ullage pressure (V43P4221C) or fuel tank ullage pressure (V43P4321C) is out of limits high or low. Oxidizer limits - High: 288 psi; Low 234 psi; Fuel limits - High: 288 psi; Low: 234 psi.

103

14:00:03.470*

103.5

45

14:00:0n.nnn

BFS Fault Message annunciation - In-determinant

103.5

14:00:0n.nnn

104

45

14:00:0n.nnn*

BFS Fault Message annunciation - SM1 AC VOLTS

Occurred after L OMS TK P message. Data is potentially error prone. *Time info corrupted.
Note: Error message indicates that AC Bus 3 phase A, B, or C voltage (V76V1700A, V75V1701A, V76V1702A) is out of limits high or low. Low limit for all 3 parameters is 108VAC; High limit is 123VAC.

104

14:00:0n.nnn*

105

45

14:00:03.637

PASS Fault Message annunciation - L RCS PVT

Data is potentially error prone.

105

14:00:03.637

106

46

14:00:03.637

PASS Fault Message annunciation - DAP DNMODE RHC

The software process which logs the PASS message runs every 1.92 seconds, so event could have occurred as early as 14:00:01.717 GMT. The fault message was corroborated by an initialization flag for the aerojet DAP roll stick function. However, during the 2 sec period, available vehicle data indicates RHC was in detent & DAP was in AUTO. Data is potentially error prone.

106

14:00:03.637

Note: BFS downlist bits indicating CSS mode are initialized to "ON" for entry because BFS does not have an "Auto" mode, is always CSS, and will drive the eyebrow panel lights ON if engaged. These bits are always on in BFS through all of OPS 3 until touchdown.

107

47

14:00:04.826

End of 2 second period of reconstructed data

Last identifiable OI Downlink frame

GMT derived by MER data personnel. Last recognizable Downlist frame (BFS & PASS) was approx 60 ms earlier.

107

14:00:04.826

108

48

14:00:17/21

Debris B observed leaving the Orbiter

Time is for debris first seen well aft of Orbiter envelope.

EOC2-4-0024
EOC2-4-0118

108

14:00:17/21

109

48

14:00:18/22

Debris C observed leaving the Orbiter

Time is for debris first seen well aft of Orbiter envelope.

EOC2-4-0024
EOC2-4-0118

109

14:00:18/22

110

49

14:00:21/25

Vehicle Main Body break-up

Onset of vehicle main body break-up

EOC2-4-0024
EOC2-4-0018
EOC2-4-0118

110

14:00:21/25

111

50

14:00:53

End of Peak Heating

Determined by analysis

111

14:00:53