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pm1weekly_2002-222_2002-228

Mission Operations Days: 2002/222 to 2002/228
August 10, 2002 00:00:00 GMT to August 16, 2002 00:00:00 GMT


There have been additional occurrences of dropped/garbled commands to MODIS. See the "MODIS Anomalies" section below for more details.


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 10, 2002

None

Sunday, August 11, 2002

None

Monday, August 12, 2002

None

Tuesday, August 13, 2002

None

Wednesday, August 14, 2002

2002/226 20:11:44-20:24:55 MCL OA16: SD/SDSM Screened, SDSM at Sun - B Side
2002/226 21:50:36-22:03:47 MCL OA15: SD/SDSM Open, SDSM at SD - B Side

Thursday, August 15, 2002

None

Friday, August 16, 2002

None

This Week's Scheduled MODIS Activities Not Completed:

None

Upcoming MODIS Events:

Remaining Calibrations for August: weekly SD/SDSM, SRCA Full Spatial, SRCA Full Spectral, Black Body, PC ECAL, and PV ECAL.

Maneuvers:

There will not be a lunar calibration roll maneuver on Aqua in August. 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:

On August 9, 2002 (DOY 2002/221), MODIS performed two SDSM calibrations, SCS 154 (OA16: SD/SDSM Screened, SDSM at Sun - B-Side) and SCS 153 (OA15: SD/SDSM Open, SDSM at SD - B- Side). At the time when SCS 153 was supposed to execute the command to have the MODIS Control Processor execute its Macro 9 (command C009) and close the SDD, the command was dropped. There was no command echo reported by the CP signifying a successful reception of the command, nor a CP event message signifying the reception of invalid command data. The dropped command occurs at the end of SCS 153. The open state of the door was not noticed in the telemetry stream until after the next SDSM calibration on August 14, 2002 (DOY 2002/226). Between those two events (DOY 2002/221 SCS 153 and DOY 2002/226 SCS 154), the SDD remained in the OPEN position. Discrepancy Report (DR) SMOdr17659 has been submitted to document this incident.

On August 13, 2002 (DOY 2002/225) at 11:24:50, the MODIS Formatter data collection rate was supposed to transition from NIGHT mode to DAY mode via SCS 56 in the MODIS MCL. However, it did not transition, leaving MODIS in NIGHT mode until 13:03, when the SCS was called again and did successfully execute. At the same time as the anomaly occurred, the CP LAST EVENT message 2E was received. This occurs when data in the Received Command Queue (RCQ) fails its validation. All data remaining in the RCQ is then discarded. It appears that the command got garbled on its way to MODIS, so that when it was received, MODIS did not understand it, and thus threw it away. This anomaly caused MODIS to stay in NIGHT mode for 1.5 orbits (about 50 minutes longer than normal). DR SMOdr17589 has been submitted to document this incident.

An anomaly review is underway to attempt to determine the cause of these two and the previous (DOY 2002/191) command loss incidents. Additionally, the review team is attempting to develop a more thorough mechanism to detect future command losses, and how to protect against any negative effects they may cause.

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

Limited Life Item Status:

SRCA 10W Lamp #1: 203.7 of 500 hours
SRCA 10W Lamp #2: 177.9 of 500 hours
SRCA 10W Lamp #3: 180.7 of 500 hours
SRCA 10W Lamp #4: 57.7 of 500 hours

SRCA 1W Lamp #1: 500.3 of 5000 hours
SRCA 1W Lamp #2: 269.8 of 5000 hours

Solar Diffuser Door: 1788 of 3022 Movements
Nadir Aperture Door: 1051 of 1316 Movements
Space View Door: 630 of 1316 Movements