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pm1weekly_2002-243_2002-249

Mission Operations Days: 2002/243 to 2002/249
August 31, 2002 00:00:00 GMT to September 06, 2002 00:00:00 GMT


Aqua Spacecraft and MODIS Instrument Status:

PM-1 "Aqua" is in Fine Pointing Normal Mode
FM1 MODIS is in Science Mode
Component State(s) Comment
Blackbody A Off; B On Nominal Science Mode
Calibration Electronics A Off; B On Nominal Science Mode
Control Processor A Off; B On Nominal Science Mode
Nadir Door Unlatched, Open Nominal Science Mode
Space View Door Unlatched, Open Nominal Science Mode
Solar Diffuser Door Unlatched, Closed Nominal Science Mode
FDDI Formatter A Off; B On Nominal Science Mode
FDDI Port A Off; B On Nominal Science Mode
FIFO Memory #1 & #2 Off; #3 & #4 On Nominal Science Mode
Format Processor A Off; B On Nominal Science Mode
Power Supplies #1 Off, #2 On Nominal Science Mode
PV VIS FPA A Off; B On Nominal Science Mode
PV NIR FPA A Off; B On Nominal Science Mode
PV SMIR FPA A Off; B On Nominal Science Mode
PV SMIR FPA A Off; B On Nominal Science Mode
PV LWIR FPA A Off; B On Nominal Science Mode
PC LWIR FPA A Off; B On Nominal Science Mode
RC Outgas Heaters All 3 (CS, IS, OS) Off Nominal Science Mode
RC LWIR FPA Heater Off Nominal Science Mode
RC SMIR FPA Heater On Nominal Science Mode
Scan Assembly A Off; B On Nominal Science Mode
SDSM Off Nominal Science Mode
SRCA Off Nominal Science Mode
PS1 Survival Heaters Enabled Nominal Science Mode
PS2 Survival Heaters Enabled Nominal Science Mode
Timing Generator A Off; B On Nominal Science Mode
Flight Software Rev BJ Nominal Science Mode
Inhibit Ids Set None Nominal Science Mode

This Week's Completed MODIS Activities:

Saturday, August 31st, 2002

2002/243 05:00:00 MCL OA26: Set Blackbody temperature to 280K
2002/243 09:00:00 MCL OA26: Set Blackbody temperature to 285K
2002/243 12:00:00 MCL OA26: Set Blackbody temperature to 290K
2002/243 16:00:00 MCL OA26: Set Blackbody temperature to 295K
2002/243 16:00:30 MCL OA26: Set Blackbody heater duty cycle to FULL
2002/243 18:00:00 MCL OA26: Set Blackbody temperature to 300K
2002/243 20:00:00 MCL OA26: Set Blackbody temperature to 315K
2002/243 23:00:00 MCL OA26: Set Blackbody temperature to 270K
2002/243 23:00:30 MCL OA26: Set Blackbody heater duty cycle to THIRD

Sunday, September 1st, 2002

2002/244 19:00:00 MCL OA26: Set Blackbody temperature to 285K

Monday, September 2nd, 2002

None

Tuesday, September 3rd, 2002

None

Wednesday, September 4th, 2002

2002/247 15:31:16 - 15:45:14 MCL OA16: SD/SDSM Screened, B-side
2002/247 17:10:08 - 17:24:06 MCL OA15: SD/SDSM Open, B-side

Thursday, September 5th, 2002

None

Friday, September 6th, 2002

None

This Week's Scheduled MODIS Activities Not Completed:

A formatter Night mode transition did not occur as planned at 16:43:53 on DOY 2002/245. There was no health & safety or operational impact to the instrument due to this missed formatter command.

Upcoming MODIS Events:

Wednesday, September 11, 2002

254/12:18:47 - 12:32:45 MCL OA16: SD/SDSM Screened, B-side
254/13:57:39 - 14:11:37 MCL OA15: SD/SDSM Open, B-side

Maneuvers:

A Drag Make-up maneuver is planned for Thursday, September 12th (2002/255) at 15:23 GMT. There will be a loss of pointing accuracy (including a yaw maneuver to +14.35 degrees) from about 14:20 to 16:20 GMT that day.

There will not be a lunar calibration roll maneuver for Aqua in September. The required roll angle would have exceeded the limit of -20 degrees.

The Deep Space Calibration pitch maneuver(s) have been indefinitely suspended pending mission review.

MODIS Anomalies:

Another MODIS stored command was "dropped" at 16:43:53 on September 2nd, 2002 (2002/245). The missed command was to set the formatter to Night rate. As a result, an extra half-orbit of day rate data were collected while the spacecraft groundtrack was over the night side of the earth. The Aqua Flight Operations Team was able to successfully dump the extra MODIS data to the ground within two EPGN contacts.

This marks the fifth dropped command event since the launch of Aqua and is the 7th MODIS command lost. The leading suspected cause of this anomaly is a timing issue between the receipt of the time synchronization data word and the receipt of the MODIS stored command.

Two Aqua flight software change requests have been submitted to correct and work-around this anomaly. The first will modify the spacecraft Bus Scheduler Task (BST) by switching the MODIS ground-command timing slots with the MODIS stored-command timing slots. This may alleviate the problem by allowing more time between the synchronization data and the stored command execution. However, the command drop risk then may transfer to commands executed in real-time ground procedures.

The second flight software change will modify two MODIS fault management Stored Command Sequences (SCSs) to include a command to disable the spacecraft "I am OK" (IMOK) signal to MODIS. This will allow MODIS to autonomously transition to Safe Mode in the event of a spacecraft anomaly instead of relying on the successful execution of stored commands. This software change should alleviate the greatest health & safety risk to the instrument due to the dropped command anomaly.

General Instrument Comments:

FM1 MODIS is in Science Mode. The SVD and NAD are Open, the survival heaters are enabled, and the Black Body is heated to 285 K.

MODIS Telemetry Trends:

The FM1 MODIS instrument telemetry is trending nominally.

Non-MODIS Significant Events:

The Aqua status can be viewed online at:
http://jupiter02.gsfc.nasa.gov/links/links.htm

Note: A password is now required to access the EOS mission links. There are directions at the above URL for how to obtain a username/password.

Limited Life Item Status:

SRCA 10W Lamp #1: 206.4 of 500 hours
SRCA 10W Lamp #2: 179.5 of 500 hours
SRCA 10W Lamp #3: 182.3 of 500 hours
SRCA 10W Lamp #4: 57.7 of 500 hours

SRCA 1W Lamp #1: 500.4 of 5000 hours
SRCA 1W Lamp #2: 269.8 of 5000 hours

Solar Diffuser Door: 1804 of 3022 Movements
Nadir Aperture Door: 1051 of 1316 Movements
Space View Door: 630 of 1316 Movements