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Mission Operations Days: 1999/352 to 1999/359
December 18, 1999 00:00:00 GMT to December 25, 1999 00:00:00 GMT

Terra Spacecraft and MODIS Instrument Status:

Terra (AM-1) is in Earth-pointing Safe Mode
Terra (AM-1) has an anomaly with SCC1
MODIS is in Survival Mode
MODIS has no known Anomalies
Component State(s) Comment
Blackbody A Off; B Off Nominal
Calibration Electronics A Off; B Off Nominal
Control Processor A Off; B On Nominal
Nadir Door Latched, Closed Nominal
Space View Door Latched, Closed Nominal
Solar Diffuser Door Latched, Closed Nominal
FDDI Formatter A Off; B Off Nominal
FDDI Port A Off; B Off Nominal
FIFO Memory #1 & #2 Off; #3 & #4 Off Nominal
Format Processor A Off; B Off Nominal
Power Supplies #1 Off, #2 Off Nominal
PV VIS FPA A Off; B Off Nominal
PV NIR FPA A Off; B Off Nominal
PV SMIR FPA A Off; B Off Nominal
PV LWIR FPA A Off; B Off Nominal
PC LWIR FPA A Off; B Off Nominal
RC Outgas Heaters All Off (CS, IS, OS) Nominal
RC LWIR FPA Heater Off Nominal
RC SMIR FPA Heater Off Nominal
Scan Assembly A Off; B Off Nominal
SDSM Off Nominal
SRCA Off Nominal
PS1 Survival Heater Enabled Nominal
PS2 Survival Heater Enabled Nominal
Timing Generator A On; B Off Nominal
Flight Software Rev BD Nominal
Inhibit Ids Set None Nominal
TMONs Enabled None Nominal

This Week's Completed MODIS Activities:

Saturday, December 18, 1999

1999/352 18:57:39 - EOS AM-1 "Terra" launched from Vandenberg Air Force Base

1999/352 EPS Enabled MODIS Power Feeds
1999/352 Enabled Survival Heaters

Sunday, December 19, 1999


Monday, December 20, 1999


Tuesday, December 21, 1999


Wednesday, December 22, 1999


Thursday, December 23, 1999


Friday, December 24, 1999


Saturday, December 25, 1999


This Week's Scheduled MODIS Activities Not Completed:


Upcoming MODIS Events:

01/03/2000: MODIS Turn on and transition to Standby Mode
01/03/2000: Unlatch Space View Door, move to Outgas position
01/03/2000: Turn on Outgas heaters

01/04/2000: Unlatch the Solar Diffuser Door
01/04/2000: Unlatch the Nadir Aperture Door

MODIS Anomalies:


General Instrument Comments:

MODIS is in a nominal Survival Mode and is a bit colder than expected with temperatures in the range of -9 to -20 degrees Celsius. The MEM survival heater is activating regularly with an approximate duty cycle of 75%. Due to these colder temperatures, next week's scheduled turn on activities have been changed from using the primary side electronics to using the redundant side.

MODIS Telemetry Trends:

The optical bench bulkhead temperature is experiencing oscillations based on the spacecraft day to night cycle. The two main electronics module temperatures as well as the FAM and KM1 temperatures are varying with the MEM survival heater cycle. The remaining three temperature sensors have reached steady-state values.

Non-MODIS Significant Events:

EOS-AM1 launched from Vandenberg Air Force Base on December 18th at 18:57:39 GMT. On launch day, 1999/352, a small glitch during the solar array deployment required the use of a redundant system to successfully deploy the array. On 1999/354 (December 20th) an anomaly, believed to be caused by a single event upset, occurred with the high gain antenna. Commanding was restored via the Omni antenna a short while later and the high gain returned to service on ops day 1999/355. The following day, the spacecraft computer put Terra into an earth-pointing safe mode and also commanded all of the instruments into safe modes. After downlinking the flight software code, it is believed that an error occurred in the TONS navigation portion of the software. At this time, the spacecraft is still in safe hold and a recovery process is scheduled to begin on December 27th.

MISR has successfully powered on and unlatched its cover. The CPHTS was turned on earlier in the mission than expected to help maintain MOPITT's temperatures at a nominal level. CERES successfully turned on both of its instruments. ASTER remains in survival mode.

Limited Life Item Status:

This summary will be deferred until next weeks report.