OPERATIONS
Science Operations
DOY = day-of-the-year; FD = Flight date. Times are in UTC.
Month | Day | Year | DOY | FD | Time | Event |
JAN | 8 | 1998 | 8 | 769 | - | OBT Frequency Adjustment |
JAN | 9 | 1998 | 9 | 770 | 18:00 | MDI Continuous Coverage, 3 month (until April 9) |
JAN | 30 | 1998 | 30 | 791 | 01:54 | Fail-over to Gyro Mode (2 hours in RMW) |
FEB | 27 | 1998 | 58 | 819 | 23:49 | Fail-over to Gyro Mode (1 hr, 42 min in RMW) |
MAR | 2 | 1998 | 61 | 822 | 14:00 | New Telemetry Subformat 3 test, ran until Warm Start-up |
MAR | 3 | 1998 | 62 | 823 | 09:02 | DHSS Warm Start-Up |
MAR | 3 | 1998 | 62 | 823 | 19:03 | ESR-3 by off-pointing |
MAR | 3 | 1998 | 62 | 823 | 22:53 | ESR-4 by roll rate; back to Normal Mode: March 5 at 00:04 UT |
MAR | 14 | 1998 | 73 | 834 | - | OBT Frequency Adjustment. |
MAR | 25 | 1998 | 85 | 846 | 2:40 | VIRGO "safe" mode (low power) until Mar. 26, @00:00 |
APR | 8 | 1998 | 98 | 859 | - | OBT Frequency Adjustment. |
APR | 10 | 1998 | 100 | 861 | 11:13 | Fail-over to Gyro Mode (2 hrs 26 min in RMW) |
APR | 17 | 1998 | 107 | 868 | 18:52 | Station Keeping Maneuver (SK08), 11 min burn,1.5kg fuel, 1.4m/s on +X |
APR | 20 | 1998 | 110 | 871 | 3:58 | Fail-over to Gyro Mode (2 hrs in RMW) |
MAY | 1 | 1998 | 121 | 882 | 17:35 | Fail-over to Gyro-Mode (1 hr, 20 min in RMW) |
MAY | 1 | 1998 | 121 | 882 | 18:05 | MDI Continuous Coverage (until May 7, 21:30 UT) |
JUN | 11 | 1998 | 162 | 923 | 15:25 | MDI Continuous Coverage (until June 18, 05:30 UT) |
JUN | 24 | 1998 | 175 | 936 | 23:16 | ESR-5 by (false) roll rate |
JUN | 25 | 1998 | 176 | 937 | 02:35 | ESR-6 by roll rate |
JUN | 25 | 1998 | 176 | 937 | 04:38 | ESR-7 by off-pointing |
JUN | 25 | 1998 | 176 | 937 | 04:43 | Loss of Telemetry |
JUL | 23 | 1998 | 204 | 965 | 10:00 | RADAR from DSN & Arecibo determine SOHO position and Spin Rate |
AUG | 3 | 1998 | 215 | 976 | 22:51 | SOHO Telemetry carrier signal received by DSN |
AUG | 8 | 1998 | 220 | 981 | 23:14 | Reception of Telemetry, Batteries charging |
AUG | 12 | 1998 | 224 | 985 | 23:39 | Begin of hydrazine tank thawing |
AUG | 28 | 1998 | 240 | 1001 | 23:02 | Completion of hydrazine tank thawing |
AUG | 30 | 1998 | 242 | 1003 | - | Begin of hydrazine lines thawing |
SEP | 16 | 1998 | 259 | 1020 | 05:45 | Begin of Attitude Recovery |
SEP | 16 | 1998 | 259 | 1020 | 18:29 | ESR-8 (Commanded as part of the recovery |
SEP | 16 | 1998 | 259 | 1020 | 18:30 | SOHO locks onto the sun |
SEP | 22 | 1998 | 265 | 1026 | 19:35 | ESR-9 by (false) off-pointng |
SEP | 22 | 1998 | 265 | 1026 | 21:32 | DHSS Warm start-up |
SEP | 23 | 1998 | 266 | 1027 | 16:58 | Attitude Control in Roll Maneuver Wheels Mode |
SEP | 25 | 1998 | 268 | 1029 | 17:30 | SK-9, Delta-V = -6.21 m/sec, 45.5 min burn, 6.7 kg fuel (in 2 segments) |
SEP | 25 | 1998 | 268 | 1029 | 19:52 | Attitude Control in Normal Mode |
OCT | 01 | 1998 | 274 | 1035 | 12:15 | SSU Patch, repeated on Oct.2 |
OCT | 04 | 1998 | 277 | 1038 | 13:15 | Fail-over to Gyro Mode (0.5 hrs in RMW) |
OCT | 05 | 1998 | 278 | 1039 | - | Instrument Recommissioning Begins |
OCT | 07 | 1998 | 280 | 1041 | 18:52 | Offset -198 arcsec |
OCT | 07 | 1998 | 280 | 1041 | ?? | Fail-over to Gyro Mode (0.5 hrs in RMW) |
OCT | 12 | 1998 | 286 | 1047 | 17:26 | Fail-over to Gyro Mode (0.5 hrs in RMW) |
OCT | 13 | 1998 | 287 | 1048 | 15:46 | OSR & FPSS duty cycle to 20%, to zero Oct 14 |
OCT | 16 | 1998 | 289 | 1050 | 21:42 | Mom. Mgmt. (-666/602/2357) & roll trim from 53 to 3 deg |
OCT | 16 | 1998 | 289 | 1050 | - | SK-10, Delta-V = 2.4 m/sec |
OCT | 17 | 1998 | 290 | 1051 | 08:17 | Fail-over to Gyro Mode (1.7 hrs in RMW) |
OCT | 17 | 1998 | 290 | 1051 | 18:52 | Fail-over to Gyro Mode (0.4 hrs in RMW) |
OCT | 17 | 1998 | 290 | 1051 | 21:11 | Fail-over to Gyro Mode (0.6 hrs in RMW) |
OCT | 19 | 1998 | 292 | 1053 | 18:17 | Close LV-B |
OCT | 23 | 1998 | 296 | 1057 | 15:35 | X-Panel duty cycle decreased by 20% (TCS2, TCS3) |
NOV | 04 | 1998 | 308 | 1069 | - | Instrument Recommissioning Ends |
NOV | 12 | 1998 | 316 | 1077 | - | Instrument Prep. for Leonids Begins |
NOV | 13 | 1998 | 317 | 1078 | 19:46 | Mom. Mgmt (-719/911/1173) & SK 11 (2m/sec) |
NOV | 15 | 1998 | 319 | 1080 | 18:30 | Roll to -120 degrees (protect for Leonids) |
NOV | 20 | 1998 | 324 | 1085 | - | SSU Patch; this time successful |
NOV | 22 | 1998 | 326 | 1087 | - | Instrument Recovery from Leonids Ends |
DEC | 21 | 1998 | 355 | 1116 | 17:49 | ESR-10 by off-pointing (loss of the last gyro) |
DEC | 21 | 1998 | 355 | 1116 | 23:30 | Started with roll rate braking (thruster 5B) |