MODIS IOT Terra Weekly Report

Mission Operations Days: 2001/349 to 2001/355
December 14, 2001 20:00:00 GMT to December 21, 2001 20:00:00 GMT

Terra Spacecraft and MODIS Instrument Status:

This Week's Completed MODIS Activities:

None

None

2001/351 14:27:45 Real-Time MOD_ALARMS_CP_ST_06(‘enabled’) procedure executed to clear the yellow alarm.

None

2001/351 14:01:30 Real-Time MOD_ALARMS_CP_ST_06(‘enabled’) procedure executed to clear the yellow alarm.
2001/353 22:09:07 ATC OA15: SD/SDSM OPEN
2001/353 22:56:55 – 23:30:28 ATC OA19: SRCA FULL RADIOMETRIC
2001/353 23:48:00 ATC OA16: SD/SDSM SCREENED

None

None

This Week's Scheduled MODIS Activities Not Completed:

None

Upcoming MODIS Events:

None

None

None

None

None

None

None

None

SD/SDSM calibrations and the monthly SRCA Full Radiometric will not be scheduled during the upcoming week. The rate of SDSM Calibrations has been reduced to one set (OA15 and OA16) every two weeks (half the previous rate). This planned reduced usage is done to extend the lifetime of the SD.

Maneuvers:

The drag makeup maneuver on December 18 was successful.

The next MODIS Lunar Calibration via a spacecraft roll maneuver is scheduled for January 3rd, 2001 (2002/003) with data collection from 11:13:22 to 11:19:52. The roll angle will be -1.9741 degrees.

Preliminary plans have begun for a Deep Space Calibration Maneuver. The execution date is expected to fall in the first week of March 2002.

MODIS Anomalies:

A review of the failed door telemetry from the December 13th NAD closing anomaly will certainly take place, but a location and time have not yet been identified.

Formatter Error Events:

As of December 21st, 2001, approximately 6.1 million formatter errors have been logged. Approximately 100,000 errors are being recorded each day, which causes the MOD_SS_CP_STATUS_08 counter to “roll over” about every 8 hours. Thirteen unique error addresses have been captured since the address buffer was last cleared on December 11.

The FR Error Rate roll over period has been fluctuating around eight hours since the middle of December. The period decreases and increases based on cooling or heating (respectively) of the MODIS electronics from internal calibrations (BB, SRCA, and SD/SDSM) activities. However, once an activity has completed, and the MODIS electronic thermal balance returns to “non- activity” levels, the error rate resumes its normal course.

Error tracking spreadsheets have been updated and can be retrieved from:

ftp://www.mcst.ssai.biz/ftp/pub/permanent/IOT/am1/analysis/FR_events/

An MS Excel spreadsheet called, AM1_FR_error_rollovers_MMDDYY.xls contains the data for the times each of the error count “roll over” occurs (with the MMDDYY denoting the date the spreadsheet was made, the more recent date containing the most up-to-date information).

General Instrument Comments:

MODIS is in Science Mode on the A-side with the SVD and NAD open, operating with the Formatter Resolution Flight Software Patches (FRFSP).

Note: SD/SDSM calibrations have been decreased to a single OPEN and SCREENED calibration every two weeks.

MODIS Telemetry Trends:

As of 2001/354, Terra's solar beta angle is approximately 22.5 degrees and on the rise. By year's end, the beta angle will be nearly 24 degrees. With this the space view door temperature is expected to decrease and the focal plane heater power margin may increase slightly. The focal plane temperatures have been steady and no additional outgassing will be required in the near future.

Non-MODIS Significant Events:

Science Data Loss Reports can be viewed at:

http://jupiter02.gsfc.nasa.gov/

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

Then press the big SUBMIT button.

Limited Life Item Status:

SRCA 10W Lamp #1: 192.8 of 500 hours
SRCA 10W Lamp #2: 147.2 of 500 hours
SRCA 10W Lamp #3: 156.4 of 500 hours
SRCA 10W Lamp #4: 61.5 of 500 hours

SRCA 1W Lamp #1: 558.6 of 4000 hours
SRCA 1W Lamp #2: 276.3 of 4000 hours

Solar Diffuser Door: 1781 of 3022 Movements
Nadir Aperture Door: 534 of 1316 Movements
Space View Door: 437 of 1316 Movements

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Last Update: Wednesday, 26-Feb-2003 16:35:36 EST