Page 1 of 2
SeaWiFS telemetry anomoly
Posted: Thu Jan 03, 2008 9:00 am America/New_York
by OB.DAAC - SeanBailey
To all SeaWiFS data users:
Please see the message from GeoEye (below) regarding OV-2 telemetry. At the
first GAC scene of 2008, the spacecraft telemetry were found to be invalid,
and the problem has not been corrected. This is affecting data processing
because there are no valid GPS or attitude data to use for navigation.
Efforts are underway at the SeaWiFS Project to reprocess the data, however,
navigation will be substantially degraded because of the lack of attitude
knowledge, and there does not appear to be any possibility of recovering
this.
Updated information will be provided as it becomes available.
Fred Patt
At year rollover, OV-2 began to experience a telemetry collection
anomaly. Imagery looked okay, however the ancillary telemetry was
invalid. A GIM hard boot did NOT remedy the anomaly. Loads are on
board through DAY 005. Imaging will continue.
SeaWiFS telemetry anomoly
Posted: Fri Jan 04, 2008 8:37 am America/New_York
by OB.DAAC - SeanBailey
The OV-2 spacecraft was commanded into Safe Haven last night, and the
SeaWiFS instrument was powered off and stowed, as GeoEye continues to
investigate the loss of GPS and attitude data in the spacecraft telemetry.
Updates will be provided as they become available.
SeaWiFS telemetry anomoly
Posted: Fri Jan 11, 2008 11:19 am America/New_York
by OB.DAAC - SeanBailey
Message from Gene Feldman on January 11th, 2008:
good morning,
as of friday morning, seawifs is still in a commanded safe haven
condition with all systems healthy. analysis of the available
telemetry data has pointed to a potential source of the initial
anomaly and a set of diagnostic and subsequent corrective actions are
being developed. extra care is being taken to make sure that the
solution that is ultimately implemented is the best one for the
long-term rather than just a quick fix since we all hope to get many
more years of valuable data out of this remarkable little spacecraft.
the important thing to remember is that the initial problem appears
to be the result of an onboard "hiccup" in the software which may
have had an impact on the handling on the stored attitude control
telemetry on the spacecraft and NOT a hardware failure on either the
spacecraft or the seawifs instrument. the fact that the spacecraft
and instrument were still performing exactly as they were supposed to
even after the event and that the only indication of a problem was
the absence of the telemetry information that was needed for
subsequent processing of the data is a very good sign, at least to
these non-engineer's mind. my hope is that we will have a better
sense of the path ahead and the schedule to accomplish it by early
next week. i will keep everyone posted as new information becomes
available.
regards for now,
gene
SeaWiFS telemetry anomoly
Posted: Tue Jan 22, 2008 6:38 pm America/New_York
by genecarlfeldman
Message from GeoEYE on January 22, 2008:
"On January 1, 2008, beginning with OrbView-2's first imagery collection
of the New Year, ancillary data associated with the imagery such as GPS
and satellite attitude information stopped being included in the
downlink.
As a result the imagery data cannot be geo-positioned, rendering it
unusable for scientific research purposes. OrbView-2 has been removed
from imaging operations for troubleshooting and diagnostics.
GeoEye remains in daily communication with OrbView-2, the satellite is
in a safe condition, and we are optimistic regarding returning OrbView-2
to service.
We have investigated the performance observations and have established a
resolution plan. This process, while time-consuming, has been performed
using the diligence and thoroughness necessary with an aging satellite.
We are finalizing the specifics of that plan to ensure that our future
actions are well-developed to restore the OrbView-2 satellite into
operations supporting the mission of the ocean color community with
minimal risk.
We anticipate resolving this issue within the next several days, and
will let you know as soon as the status changes."
SeaWiFS telemetry anomoly
Posted: Fri Feb 08, 2008 8:27 am America/New_York
by OB.DAAC - SeanBailey
here is the latest information from geoeye regarding the status for
the planned restoration of routine seawifs imaging operations.
hopefully, we'll have some specific and positive news to pass along
next week. a large, collective crossing of fingers would be most
appreciated.
regards,
gene
Dear OrbView-2 SeaWiFS Users,
GeoEye remains in daily communication with OrbView-2, the satellite
and SeaWiFS sensor are in a safe condition, and we continue to be
optimistic regarding returning OrbView-2 to service.
We continue to make progress on finalizing a recovery plan and will
advise when there is a change in operational status.
We appreciate your patience during this process.
Best Regards,
GeoEye
SeaWiFS telemetry anomoly
Posted: Wed Feb 27, 2008 8:56 am America/New_York
by OB.DAAC - SeanBailey
The following is an update on the status of SeaWiFS from GeoEye.
February 27th, 2008 03:26 EST:
I am happy to report we successfully switched to SCC-2 on OV-2 during
our 1st contact this evening. On the 2nd contact we performed the GPS
receiver commanding. Everything looks nominal except for a few
callback "odditities" which we need to investigate further Wednesday
morning. We are now on SCC-2 and it is functional with a date of
1/1/1994.
On our 1st daytime contact on 2/27/08, we'll assess the GPS receiver
status as well as review the entire spacecraft telemetry. However, as
of right now, Phase 1 of our SCC Switch and recovery as documented in
our SCC Switch procedure, is completed. We just need to see what
clean up commanding may be necessary.
SeaWiFS telemetry anomoly
Posted: Wed Mar 12, 2008 8:49 am America/New_York
by OB.DAAC - SeanBailey
Message from March 11th, 2008:
good evening,
i am very happy to be able to report that as of late this afternoon,
the geoeye ground controllers commanded seawifs to resume routine
imaging operations and the first hrpt pass over the united states
west coast has been received and looks good. the real test will be
tonight at which time we hope to receive the first s-band downlink
containing the first complete orbits of data since the beginning of
the new year. once that pass is received and processed successfully,
i think that we can all breathe a collective sigh of relief.
thanks for hanging with us during this long, difficult, and at times
nerve wracking experience.
regards,
gene
SeaWiFS telemetry anomoly
Posted: Thu Mar 13, 2008 10:33 am America/New_York
by OB.DAAC - SeanBailey
Message from March 13th, 2008:
folks,
just a quick note to say that seawifs decided that it wasn't quite
ready to come out of early retirement and went out of imaging mode
soon after the successful data downlink that i reported yesterday
morning. the good news is that the source of this anomaly is
understood and corrective actions are currently underway.
just make sure that your seatbelts are fastened and stay in your
seats because the roller coaster ride isn't quite over yet. will
keep you posted as information becomes available.
regards,
gene
SeaWiFS telemetry anomoly
Posted: Mon Mar 17, 2008 1:13 pm America/New_York
by genecarlfeldman
Update as of 17 March 2008:
Work continues on returning SeaWiFS to full imaging mode although a target date for that to happen has not been established. At this time the spacecraft and instrument are fine and a series of table updates to the onboard software are being carried out to restore all the parameters to pre-anomaly values. Once that has been done and verified, I would anticipate that a schedule for resumption of imaging will be decided upon. Will keep you posted as new developments warrant.
Regards,
gene
SeaWiFS telemetry anomoly
Posted: Thu Mar 27, 2008 3:25 pm America/New_York
by genecarlfeldman
Update as of 27 March 2008:
Work continues on returning SeaWiFS to full imaging mode although a target date for that to happen has not been established. At this time the spacecraft and instrument are fine, the spacecraft power system is normal, GPS tracking has been restored and a series of table updates to the onboard software are being carried out to restore all the parameters to pre-anomaly values. As yet, however, there is no definitive schedule that has been provided for resumption of imaging. Non-critical updates will be posted to the Ocean Color Announcements section on the OceanColor forum as they become available at:
http://oceancolor.gsfc.nasa.gov/forum/oceancolor/forum_show.plbut any major change in the situation will be sent via e-mail to the oceancolor mailing list.
I'll keep you posted as new developments warrant.
Regards for now,
gene