MODIS IOT Terra Weekly Report

Mission Operations Days: 2001/321 to 2001/327
November 16, 2001 20:00:00 GMT to November 23, 2001 20:00:00 GMT

Terra Spacecraft and MODIS Instrument Status:

This Week's Completed MODIS Activities:

None

None

None

None

2001/325 21:40:50 ATC OA15: SDSM Open
2001/325 22:32:18 – 23:05:51 ATC OA19: SRCA Full Radiometric
2001/325 23:19:44 ATC OA16: SDSM Screened

2001/326 08:25:38 – 09:23:09 ATC OA23: SRCA Full Spatial

None

This Week's Scheduled MODIS Activities Not Completed:

None

Upcoming MODIS Events:

Two SD/SDSM calibrations will be scheduled during the upcoming week.

Maneuvers:

Due to a sharp decrease in drag, the December 5th drag make-up maneuver has been postponed. The next DMU maneuver is expected to occur after the inclination maneuver (December 12th) but before the holidays.

The next MODIS Lunar Calibration via a spacecraft roll maneuver is scheduled for December 5th, 2001 with data collection from 03:37:06 to 03:43:36. The roll angle will be -7.7541 degrees.

The current plan for Terra orbit inclination adjustment maneuvers is to perform six burns, one each month from December 2001 to May of 2002. They planned burn dates to maintain a 10:30 +/- 00:05 mean local equator crossing time are:

December 12, 2001
January 16, 2002
February 13, 2002
March 13, 2002
April 17, 2002
May 15, 2002

Currently, MODIS' planned configuration for the inclination maneuvers will be to close the Nadir Aperture Door and schedule a stored command to close the Space View Door before Terra would re-enter sunlight. The stored command will be inhibited if the return yaw slew goes nominally.

MODIS Anomalies:

Formatter Error Events:

As of November 23rd, 2001, approximately 3.4 million formatter errors have been logged. Approximately 80,000 errors are being recorded each day which causes the MOD_SS_CP_STATUS_08 counter to “roll over” about every 9-11 hours. Thirteen unique error addresses have been captured since the address buffer was last cleared.

The FR Error Rate roll over period has been fluctuating between nine and eleven hours since the beginning of November. 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/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 will be decreased to one OPEN and one SCREENED calibration every two weeks starting in December, 2001.

MODIS Telemetry Trends:

As of 2001/320, Terra's solar beta angle is approximately 19.3 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:

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: 192.7 of 500 hours
SRCA 10W Lamp #2: 147.1 of 500 hours
SRCA 10W Lamp #3: 156.3 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: 1763 of 3022 Movements
Nadir Aperture Door: 532 of 1316 Movements
Space View Door: 437 of 1316 Movements

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Last Update: Wednesday, 26-Feb-2003 16:07:37 EST