problems with its housekeeping data. This has resulted in the loss of all
datasets from that point on. NASA is currently investigating the problem.
Until this problem is resolved, there will be no MODIS-Aqua data available.
The FOT (Flight Operations Team) is still trying to recover from an anomaly
that prevented them from writing to the SSR (Solid State Recorder) partition
where the S/C (Spacecraft) engineering and GBAD (Ground Based Attitude Data)
data are written. While they successfully recovered the capability to write to
the recorder, there are questions as to the quality of the data as observed by
EDOS (Earth Observing System Data and Operations System-they provide Rate
Buffered Data to NRTPE). Science partitions were not impacted. Efforts to
recover from this anomaly are still underway and the SSR vendor has been
contacted and is being consulted at this time.
Efforts are underway to repair the partition and return it to normal
use. However, the earliest estimate for completion is Thursday Dec. 6th.
FROM: Earth Science Mission Operations (ESMO) Project
DATE: December 3, 2007
PROGRAM: EOS Aqua
DATE OF ANOMALY: December 2, 2007
There is no immediate impact to the Aqua spacecraft operation and all
instruments are operating normally. All of the other SSR partitions are
functioning normally. Science data is being recorded and dumped
nominally. Spacecraft engineering data is being recorded on the S-Band
data partition and is being dumped as time allows after completion of
the X-Band science data capture.
Direct Broadcast (DB) data is unaffected. GBAD data is being correctly
sent via DB.
CORRECTIVE ACTION: An Anomaly Recovery Team (ART) was assembled which
includes the Aqua Mission Director, the spacecraft manufacturer,
Northrop Grumman Space Technology (NGST) and members of the Aqua Flight
Operations Team (FOT). The FOT is working with NGST, who manufactured
the SSR, to develop a recovery plan.
attitude data required to process the files are arriving at a
slower pace, therefore processing beyond Level 0 is intermittent.
As the attitude data are ingested, the corresponding Level 0 data
will be processed. The processed files will be made available via
our normal distribution methods.
1. All recoverable X-band GBAD data from DOY 337 through DOY 342 have been
processed and distributed.
2. All data from DOY 343 is expected to be distributed this evening.
3. A report of GBAD gaps from anomaly start to present will be distributed
Monday morning. This report will provide gap times, durations, and reasons.
In summary, most gaps are due to 1-2 packets missing from between passes.
Large gaps are due to the previously reported SG3 and SKS LOR limitations.
The FOT is investigating the possibility of recovering these larger gaps
from the S-band housekeeping for days 337-341, however it is believed that
the fidelity of the housekeeping data is not accurate enough to be useful.
EDOS currently plans to support the Aqua GBAD recovery effort 12 hours a
day. As a result, users should expect a delivery delay of approximately 12
hours for the earliest data on the unsupported shift (assuming no or very
limited use of LOR replays). This staffing approach will allow us to provide
some level of analysis support to Aura, as well as attempt to maintain some
progress with C5.1 testing. We plan to discuss on Monday the possibility of
further automating the workaround, but in the meantime we hope this delayed
delivery is acceptable to our customers during this anomalous period.
Subject: Good News! Aqua Anomaly Resolved
The Flight Operations Team and the spacecraft developer, NGST, successfully
implemented a ground-based work-around fix to the Aqua anomaly that occurred
on December 2nd. From 2 consecutive passes, analysis shows that the output
data from partition 6 is back to its nominal format.This will enable
resumption of nominal data processing operations for users of Aqua data,
including the near-realtime community that accesses its data via the NOAA
Please note that the fix implemented today is a temporary solution until we
resolve the onboard problem with partition 6.