Mission Operations Days: 2003/270 to 2003/276
September 27, 2003 00:00:00 GMT to October 03, 2003 00:00:00 GMT
Terra Spacecraft and MODIS Instrument Status:
| AM-1 "Terra" is in Normal Mode PFM MODIS is in A-Side Nominal Science Mode (Cross Strapped with FR B) |
||
|---|---|---|
| Component | State(s) | Comment |
| Blackbody | A On (290K); B Off | Nominal Science Mode |
| Calibration Electronics | A On; B Off | Nominal Science Mode |
| Control Processor | A On; B Off | Nominal Science Mode |
| Nadir Door | Unlatched, Open | Nominal Science Mode |
| Space View Door | Unlatched, Open | Nominal Science Mode |
| Solar Diffuser Door | Unlatched, Screened | Permanent Configuration |
| FDDI Formatter | A On; B Off | Nominal Science Mode |
| FDDI Port | A On; B Off | Nominal Science Mode |
| FIFO Memory | #1 & #2 On; #3 & #4 Off | Nominal Science Mode |
| Format Processor | A Off; B On | Nominal Science Mode |
| Power Supplies | #1 On, #2 Off | Nominal Science Mode |
| PV VIS FPA | A On; B Off | Nominal Science Mode |
| PV NIR FPA | A On; B Off | Nominal Science Mode |
| PV SMIR FPA | A On; B Off | Nominal Science Mode |
| PV LWIR FPA | A On; B Off | Nominal Science Mode |
| PC LWIR FPA | A On; B Off | Nominal Science Mode |
| RC Outgas Heaters | All 3 (CS, IS, OS) Off | Nominal Science Mode |
| RC LWIR FPA Heater | On (83K) | Nominal Science Mode |
| RC SMIR FPA Heater | Off | Nominal Science Mode |
| Scan Assembly | A On; B Off | Nominal Science Mode |
| SDSM | Off | Nominal Science Mode |
| SRCA | Off | Nominal Science Mode |
| PS1 Survival Heater | Enabled | Nominal Science Mode |
| PS2 Survival Heater | Enabled | Nominal Science Mode |
| Timing Generator | A On; B Off | Nominal Science Mode |
| Flight Software | Rev BD + 11 sets of patches
|
Nominal Science Mode |
| Inhibit Ids Set | none | Nominal Science Mode |
| TMON 66 | Disabled | Nominal Science Mode |
| TMON 67 | Disabled | Nominal Science Mode |
| TMON 68 | Enabled | Nominal Science Mode |
| TMON 69 | Disabled | Nominal Science Mode |
This Week's Completed MODIS Activities:
Saturday, September 27, 2003
None
Sunday, September 28, 2003
None
Monday, September 29, 2003
None
Tuesday, September 30, 2003
2003/273 20:56:58-21:05:46 ATC MOD_OA16_SDSM_SCRN_NO_DOOR_A.4 OA-16: SD/SDSM screened side A, no door movement.
Wednesday, October 1, 2003
None
Thursday, October 2, 2003
None
Friday, October 3, 2003
None
This Week's Scheduled MODIS Activities Not Completed:
None
Upcoming MODIS Events:
October calibrations will include biweekly SDSM, monthly SRCA Full Radiometric, monthly 10W Radiometric, and quarterly SRCA Full Spectral and Blackbody calibrations. In addition, a full set of memory table dumps will be gathered.
Tuesday, October 7, 2003
2003/280 21:04:05-21:12:53 ATC MOD_OA16_SDSM_SCRN_NO_DOOR_A.4 OA-16: SD/SDSM screened side A, no door movement.
2003/280 22:10:30-22:35:30 ATC MOD_OA20_SRCA_10W_RAD_A.3 OA-20: SRCA 10W Continuous Radiometric - A Side, Using Lamp #1 Data collection is from 22:30:00-22:35:30 (in S/C Night)
Maneuvers:
The next Lunar Roll Calibration is planned for DOY 2003/288 (October 15, 2003). The data collect will occur between 08:35:34 and 08:42:04 GMT with a spacecraft roll angle of -13.16 degrees.
The next Terra inclination maneuvers are expected in October of 2004.
MODIS Anomalies:
Terra Solid State Recorder Anomaly
Although no directly the result of a MODIS problem, the most recent Printed Wire Assembly (PWA) failures in the Terra Solid State Recorder (SSR) do affect MODIS data. See the Non-MODIS Significant Events section below for more details.
General Instrument Comments:
MODIS is in Science Mode, using all A-side components, but cross-strapped to Formatter B, with the blackbody maintained at 290K and the Solar Diffuser Door at the Screened position.
MODIS Telemetry Trends:
Nominal telemetry trending is ongoing.
Non-MODIS Significant Events:
Terra Solid State Recorder Anomaly
Two Printed Wire Assemblies (PWA) in the Terra Solid State Recorder (SSR) have autonomously powered- down. The first shut down on September 24, 2003 (2003/267) at approximately 23:10 GMT. This PWA contains supersets #50 and #51 that are assigned as MODIS buffer locations. The second PWA shut down September 25, 2003 (2003/268) at 07:30 GMT. This second PWA contains supersets #114 and #115 that are assigned to the ASTER instrument. It is believed that the PWA shutdowns were caused by over-current protection circuits in each PWA.
The data written to these supersets while they were powered off are not recoverable. The four failed supersets were moved to the "bad" list and will no longer have data written to them. This reduced MODIS' total SSR buffer space from 36 supersets to 34 supersets and resulted in a short data loss while the transition was made.
Note that MODIS started the mission with 35 supersets of SSR space. A similar PWA failure occurred in May of 2001 with the net result of MODIS gaining 1 superset (up to 36) when the SSR was recycled in June of 2001. It is believed that recycling the SSR will return all of the failed SSR supersets (currently 6) to working operation.
The final SSR playback before the PWA re-assignment was at 18:06:15 GMT on September 25, 2003 (2003/268). Science data recording to the SSR was stopped at 18:36:54 and re-enabled at 18:51:14. During this time, there will be no MODIS science data. For the period between 18:06:15 and 18:36:54, some or all of that MODIS data may be lost as well. The exact amount is not known at this time.
One Superset was moved from the MISR buffer to the MODIS buffer at 12:22:17 GTM on September 30, 2003 (2003/273). This brings the count of Supersets in the MODIS buffer to 35, its original count from mission start. Science Data recording during the reassignment was disabled between 12:16:29 and 12:28:25 GMT.
At this time, there are no plans to power-cycle the SSR to (hopefully) return all of the PWAs to working order because of other potential risks to the SSR during a power-cycle. The MODIS IOT has been asked to consider reducing its Science Data rate from the current orbital collection of 50% Day/50% Night to a 45/55 or 40/60 Day/Night rate. Such a reduction would aid the FOT in their replay management of the SSR buffers. Currently there are no plans to make this reduction. However, the MODIS IOT is taking steps to be prepared to support such a request, should it occur in the future. Additionally, further Superset reassignments by the FOT to balance Science Data storage may be necessary, should additional PWA losses occur.
A brief timeline of the command activities follows:
Wednesday, September 24, 2003
2003/267 23:12:00 SSR PWA containing supersets 50 & 51 (MODIS) shuts down
Note: About 5-1/2% MODIS data is lost until the supersets are moved to the "bad" list
Thursday, September 25, 2003
2003/268 07:37:00 SSR PWA containing supersets 114 & 115 (ASTER) shuts down
2003/268 18:06:15 Last SSR playback before re-assigning failed supersets to the "bad list"
2003/268 18:36:54 Science recording to the SSR is disabled
2003/268 18:51:14 Science recording to the SSR is re-enabled
Note: Science data loss occurred while the recording was disabled. Some or all of the data since the last SSR playback may be lost as well.
Tuesday, September 30, 2003
2003/273 12:16:29 Science recording to the SSR is disabled
2003/273 12:17:25 Housekeeping recording to the SSR is disabled
2003/273 12:22:17 One MISR superset moved to MODIS
2003/273 12:28:25 Science recording to the SSR is re-enabled
2003/273 12:29:24 Housekeeping recording to the SSR is re-enabled
The EMOS mission status webpage (which includes instrument data loss records) can be found at the following URL. Note that a password is now required to access the EOS mission links web pages. There are directions at the URL below for how to obtain a username/password.
http://jupiter02.gsfc.nasa.gov/links/links.htm
Limited Life Item Status:
SRCA 10W Lamp #1: 217.4 of 500 hours
SRCA 10W Lamp #2: 161.7 of 500 hours
SRCA 10W Lamp #3: 170.9 of 500 hours
SRCA 10W Lamp #4: 62.2 of 500 hours
SRCA 1W Lamp #1: 562.6 of 4000 hours
SRCA 1W Lamp #2: 276.7 of 4000 hours
Solar Diffuser Door: 2146 of 3022 Movements
Nadir Aperture Door: 536 of 1316 Movements
Space View Door: 439 of 1316 Movements