MODIS IOT Terra Weekly Report

Mission Operations Days: 2002/075 to 2002/081
March 15, 2002 20:00:00 GMT to March 22, 2002 20:00:00 GMT

The Terra spacecraft was autonomously put into Safe Mode on Tuesday, March 19, 2002 (2002/078), at 16:10:49 GMT. As a result, MODIS was also put into Safe Mode which turns off nearly all instrument components and closes the nadir and space view doors.

Terra returned to Normal Mode on Wednesday, March 20, 2002 (2002/079), at 16:35:00 GMT. Shortly thereafter, MODIS was transitioned to Standby Mode, the Space View Door was opened, and the scan mirror was started. There is no science production in this configuration.

Sneak Peak:
An attempt was made to recover the instrument to Science Mode on Saturday, March 23, 2002 (2002/082), at about 01:10 GMT. The instrument was transitioned to science mode. When the A-side formatter was powered on, the expected reset errors occurred. The formatter was commanded to upload mode in order for the formatter anomaly patches to be loaded, but the formatter never stabilized in upload mode. After waiting a couple of hours for the formatter to warm itself, it was still not responding and the instrument was returned to standby mode with the scan mirror rotating.

Terra Spacecraft and MODIS Instrument Status:

This Week's Completed MODIS Activities:

None

None

2002/077 20:53 Real-time FOT sets MODIS inhibit IDs #34 and #58 in preparation for inclination maneuver #5

Terra inclination adjust maneuver #5 of 6
2002/078 14:46:00 Real-time FOT commands Terra to low fidelity pointing mode
2002/078 15:28:00 – 15:35:30Real-TimeSpacecraft forward slew (yawed –90 degrees)
2002/078 15:35:30 – 15:51:07Real-TimeDuring this period the spacecraft performs 320 second inclination burn
2002/078 15:51:07 – 15:58:37Real-TimeSpacecraft return slew (yawed back 90 degrees)
2002/078 16:10:49 Real-time Terra spacecraft autonomously enters Safe Mode. All instruments are sent to safe mode as well. This turns off most MODIS components, closes the MODIS nadir and space view doors, and stops MODIS science data production.

2002/079 16:35:00 Real-time FOT commands Terra spacecraft to Normal Mode
2002/079 16:47:00 Real-time FOT commands Terra to high fidelity pointing mode
2002/079 17:48:37 – 17:49:31 Real-time Memory dump of MODIS door position table MOD_MEM_DUMP(144,12,0,0,1,1)
2002/079 17:50:12 – 17:51:17 Real-time MODIS transition to A-side Standby Mode MOD_STBY_TXTN_A
2002/079 17:51:57 – 17:54:50 Real-time MODIS Space View Door (SVD) is opened MOD_SVD_TO_OPEN
2002/079 17:55:11 – 17:55:50 Real-time Memory dump of MODIS door position table MOD_MEM_DUMP(144,12,0,0,1,1)
2002/079 17:57:16 Real-time CP Status #6 alarm disabled MOD_ALARMS_CP_ST_06(‘DISABLE’)
2002/079 17:57:36 Real-time UART Reset alarm disabled MOD_ALARMS_URT_RST(‘DISABLE’)
2002/079 17:57:53 Real-time Formatter reset source alarm disabled MOD_ALARMS_FR_SRC(‘DISABLE’)
2002/079 19:36:47 – 19:37:23 Real-time Turn on A-side Scan Assembly MOD_SA_ON(‘A’)

None

2002/081 18:50:50 Real-time FOT clears MODIS inhibit ID# 32 (BB)
2002/081 18:51:23 Real-time FOT clears MODIS inhibit ID# 33 (CP)
2002/081 18:51:50 Real-time FOT clears MODIS inhibit ID# 34 (SVD/NAD)
2002/081 18:52:20 Real-time FOT clears MODIS inhibit ID# 54 (SRCA)
2002/081 18:52:46 Real-time FOT clears MODIS inhibit ID# 58 (SDD)

This Week's Scheduled MODIS Activities Not Completed:

2002/078 15:59:25 – 16:01:06 ATC MOD_CLOSE_NAD_SVD.1 Contingency for TERRA inclination adjust; this activity was inhibited.

Upcoming Week's MODIS Events:

Sneak Peak:

2002/082 01:11:25 – 01:13:39Real-timeMODIS Transition to A-side Science Mode MOD_SCI_TXTN_A
2002/082 01:14:30 – 01:15:03Real-timeAttempt to reset Formatter to Upload Mode MOD_FR_RESET_UPLD
2002/082 01:15:15 – 01:15;50Real-timeAttempt to dump formatter patch memory part 1 MOD_MEM_DUMP(6,2,11706,0,1,1)
2002/082 01:26:44 – 01:26:58Real-timeAttempt to reset Formatter to Upload Mode MOD_FR_RESET_UPLD
2002/082 02:17:11 – 02:17:30Real-timeClear memory load transfer MOD_MEM_HALT
2002/082 05:13:43 – 05:14:01Real-timeAttempt to reset Formatter to Upload Mode MOD_FR_RESET_UPLD
2002/082 05:14:54 – 05:15:13Real-timeAttempt to reset Formatter to Normal Mode MOD_FR_RESET_STD
2002/082 05:16:25 – 05:16:59Real-timeTurn off Formatter MOD_FR_OFF
2002/082 05:17:18 – 05:18:11Real-timeTurn on A-side Formatter MOD_FR_ON(‘A’)
2002/082 05:22:11 – 05:22:36Real-timeRun macro 0 to turn off most instrument components MOD_RUN_MACRO(0)
2002/082 05:23:12 – 05:24:18Real-timeTransition to A-side Standby Mode MOD_STBY_TXTN_A
2002/082 05:24:27 – 05:24:45Real-timeTurn on A-side Timing Generator MOD_TG_ON(‘A’)
2002/082 05:24:56 – 05:25:28Real-timeTurn on A-side Scan Assembly MOD_SA_ON(‘A’)
2002/082 05:57:27Real-timeFOT sets MODIS inhibit ID# 33 (CP)
2002/082 05:57:48Real-timeFOT sets MODIS inhibit ID# 53 (SDSM)
2002/082 05:58:21Real-timeFOT sets MODIS inhibit ID# 58 (SDD)

Maneuvers:

There will be no MODIS Lunar Calibration at the beginning of April because the required roll angle will exceed the allowable limit.

The sixth Terra inclination maneuver will occur on April 2, 2002 (2002/092) (two days earlier than previously planned).

The Terra Deep Space Calibration Maneuver is still postponed. The maneuver date is not expected until late summer of 2002.

MODIS Anomalies:

The MODIS Formatter is not powered on at this time, therefore, no new error events are being recorded.

The most recent error tracking spreadsheets can be retrieved from:

An MS Excel spreadsheet called, AM1_FR_error_rollovers_current.xls contains the data for the times each error count "roll over" occurs.

Sneak Peak:
An attempt was made to recover the MODIS instrument to Science Mode starting at 01:10 GMT Saturday, March 23, 2002 (2002/082). The instrument was commanded to science mode and all subsystems powered on nominally except that the serial link to the formatter was only established for a brief time before the formatter reset. The formatter reset to upload mode command was sent, but no verification of upload mode was received and the formatter error patches could not be loaded.

The formatter engine temperature was approximately -20C when first powered on. Four contacts later, the temperature was about -11C and still a stable serial link was not able to be established in order to maintain formatter upload mode. After attempting another formatter upload reset command, a formatter standard reset command, and cycling the formatter power, all without success, the instrument was returned to low-power standby mode with the A-side timing generator and scan mirror powered. This was the instrument configuration prior to the recovery attempt.

General Instrument Comments:

MODIS is in A-side Standby Mode not generating science data. The A-side Timing Generator (TG) and Scan Assembly (SA) are powered on. The Space View Door (SVD) has been re-opened, but the Nadir Aperture Door (NAD) remains closed.

MODIS Telemetry Trends:

The MODIS instrument is in a low-power mode. General instrument temperatures have decreased while the radiative cooler temperatures increased while the Space View Door (SVD) was closed. Upon opening the SVD, the radiative cooler temperatures began to decrease to the desired cold stage temperature of 73K. The survival heaters have maintained the temperature of the instrument within a safe range.

Non-MODIS Significant Events:

The Terra spacecraft was autonomously put into Safe Mode on Tuesday, March 19, 2002, (2002/078) at 16:10:49 GMT. Following the completion of inclination maneuver #5, the Terra spacecraft was commanded to its normal mode for fault detection when the yaw error was still slightly too high. The fault detection system observed the "high" yaw error and commanded the spacecraft to Safe Mode. As a result, MODIS was also put into Safe Mode which turns off nearly all instrument components and closes the nadir and space view doors. The Terra spacecraft was recovered to Normal Mode on March 20^th, 2002.

Science Data Loss Reports can be viewed at:

Select "Search Data Losses" and choose Data Type: MOD

Then press the big SUBMIT button.

Limited Life Item Status:

SRCA 10W Lamp #1:196.3 of 500 hours
SRCA 10W Lamp #2: 149.4 of 500 hours
SRCA 10W Lamp #3: 158.6 of 500 hours
SRCA 10W Lamp #4: 61.5 of 500 hours

SRCA 1W Lamp #1: 559.2 of 4000 hours
SRCA 1W Lamp #2: 276.3 of 4000 hours

Solar Diffuser Door: 1823 of 3022 Movements
Nadir Aperture Door: 535 of 1316 Movements
Space View Door: 439 of 1316 Movements

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Last Update: Thursday, 04-Sep-2003 18:14:23 EDT