PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2007-07-31 NOTE = " E-mail and other messages concerning MGS Radio Science on or about 2002/058." END_OBJECT = TEXT END From aseel@airmail.fltops.jpl.nasa.gov Fri Mar 1 01:14:22 2002 Date: Thu, 28 Feb 2002 19:21:01 GMT From: aseel anabtawi To: aseel.anabtawi@jpl.nasa.gov, data@magellan.stanford.edu, joe@neptune.stanford.edu, kusza@magellan.stanford.edu, rsimpson@magellan.stanford.edu DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13288 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-02:53:00 End Record: 2002/058-03:01:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13289 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-03:31:00 End Record: 2002/058-03:40:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13289 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-04:50:00 End Record: 2002/058-04:59:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13290 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-05:29:00 End Record: 2002/058-05:38:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13290 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-06:48:00 End Record: 2002/058-06:57:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13291 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-07:27:00 End Record: 2002/058-07:35:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13291 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-08:46:00 End Record: 2002/058-08:54:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13292 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-09:24:00 End Record: 2002/058-09:33:00 -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Thu Feb 28 18:03:13 2002 Date: Wed, 27 Feb 2002 22:05:01 GMT From: aseel anabtawi To: aseel.anabtawi@jpl.nasa.gov, data@magellan.stanford.edu, joe@neptune.stanford.edu, kusza@magellan.stanford.edu, rsimpson@magellan.stanford.edu DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 13297 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-19:13:00 End Record: 2002/058-19:22:00 DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 13297 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-20:32:00 End Record: 2002/058-20:41:00 DSS: 65 RSR: RSR2A Subchannel: 1 Orbit Number: 13298 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-21:11:00 End Record: 2002/058-21:20:00 -------------------------------------------------------------------------- From aseel@godzilla.jpl.nasa.gov Thu Feb 28 18:02:54 2002 Date: Wed, 27 Feb 2002 14:09:06 -0800 (PST) From: Aseel Anabtawi To: rsimpson@magellan.stanford.edu, joe@nova.stanford.edu, Kusza@magellan.stanford.edu Cc: Sami.W.Asmar@jpl.nasa.gov Hello, The last measurement over DSS-65, which extended beyond EOT and was also the first over DSS-15, had an SNR of ~13 dB. The SNR is about 15-17 dB over DSS-15 as we speak. The cause of this is still unknown, but the ACE and the station are working on it, and DSS-14 was asked to help investigate the problem. Stay tuned. Regards, Aseel -------------------------------------------------------------------------- From sami.asmar@jpl.nasa.gov Thu Feb 28 18:03:02 2002 Date: Wed, 27 Feb 2002 15:19:48 -0800 From: Sami Asmar To: Aseel Anabtawi , rsimpson@magellan.stanford.edu, joe@nova.stanford.edu, Kusza@magellan.stanford.edu Cc: Sami.W.Asmar@jpl.nasa.gov Subject: Re: It was just reported at the ER meeting that MGS lost lock due to STAREX problem with star identification and a 70-m station was brought to radiate commands to bring it back. At 02:09 PM 2/27/2002 -0800, Aseel Anabtawi wrote: >Hello, > >The last measurement over DSS-65, which extended beyond EOT and was >also the first over DSS-15, had an SNR of ~13 dB. The SNR is about >15-17 dB over DSS-15 as we speak. The cause of this is still unknown, >but the ACE and the station are working on it, and DSS-14 was asked to >help investigate the problem. Stay tuned. > >Regards, >Aseel -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Fri Mar 1 01:22:23 2002 Date: Thu, 28 Feb 2002 19:17:03 GMT From: aseel anabtawi To: Kusza@magellan.stanford.edu, Sami.W.Asmar@jpl.nasa.gov, aseel@rsops2.fltops.jpl.nasa.gov, hinson@rocc.stanford.edu, joe@nova.stanford.edu, len@nova.stanford.edu, rsimpson@magellan.stanford.edu Subject: Fwd: MGS Anomaly Status The last successful measurement was 13297i over DSS-65. 13298e over DSS-65 and DSS-15 had a very weak signal, and so did 13298i over DSS-15. All measurements that followed had no signal. >From: Gene Brower >To: MGS Dist:; >Subject: MGS Anomaly Status >Date: Wed, 27 Feb 2002 22:09:34 -0800 > >ALL, > >MGS downlink carrier signal started to degrade then was lost on >Wednesday February 27. > >At approximately 02-058/19:24 (SCET) after a new Y-axis Gyro scale >factor update was uploaded and a STAREX reset (part of the scale >factor update process) was commanded. At this time the star >identification process began to show convergence problema and >unidentified star counter started to incremented displaying higher >than normal values. When the downlink signal was expected to return >after occultation, AGC levels were lower than expected and telemetry >became limited. The downlink signal continued to degrade to the >point >the carrier signal was not seen by the DSN stations (Both 34-meter >and 70-meter). > >When the initial star processing problems first were noticed, >contingency commands were built to command the spacecraft to the >nadir orientation, so that MHSA inputs could be included in the >attitude determination. Commands to return to nadir were radiated >numerous times over both 34-meter and 70- meter DSN stations but >these command were unable to be confirmed received by the >spacecraft. >With lack of downlink carrier signal and after continued attempts to >return MGS to a nadir orientation a decision was made to stop >commanding MGS in the hopes that the problem would correct the error >autonomously or MGS would enter C-mode. > >On Thursday morning at 7:30 am (Pacific) a status meeting to discuss >recovery options will be held on the MGS MeetMe line 818-393-4544. > > >Thank You, > >Gene Brower >Mars Global Surveyor Mission Manager >M/S: 264-235, Office: 264-212 >Phone: OFFICE: (818)393-0943 > CELL: (818)645-5943 -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Fri Mar 1 01:22:41 2002 Date: Thu, 28 Feb 2002 19:43:22 GMT From: aseel anabtawi To: Kusza@magellan.stanford.edu, aseel@rsops2.fltops.jpl.nasa.gov, joe@nova.stanford.edu, rsimpson@magellan.stanford.edu Subject: Lost Data Hello, The script continued to executed as planned over DSS-15 yesterday (DOY 058/059), so if you query for the data you will get it, but except for the first two measurements which had a very weak signal, all you'll be seeing is noise. I don't think the first two will be of any use for science. The script also executed as planned over DSS-45 (BOT 059/0430), but none of the measurements had a signal. I noticed that the station was using RSR1 to look for the MGS signal. The scripts executed during last night's DSS-65 pass (BOT 059/0940), but someone (at the station, it seems) stopped the script and RSR1 and RSR2 were used to look for the signal. No date were collected over this pass, so you won't be receiving an email notification for this one. Even if data were collected, it would've been all noise. Should I continue to collect data and send you email notifications only if the measurements were successful, or should I stop until MGS is back to nominal. The only reason I would think to stop is that for the RSRs to be used to look for the signal, but I don't know if all four RSRs (six at Goldstone) are needed for the search. Regards, Aseel -------------------------------------------------------------------------- From rsimpson@magellan.stanford.edu Fri Mar 1 01:22:52 2002 Date: Thu, 28 Feb 2002 11:47:00 -0800 (PST) From: Dick Simpson 723-3525 To: Kusza@magellan.stanford.edu, aseel@airmail.fltops.jpl.nasa.gov, aseel@rsops2.fltops.jpl.nasa.gov, joe@nova.stanford.edu, rsimpson@magellan.stanford.edu Subject: Re: Lost Data >Should I continue to collect data and send you email notifications >only if the measurements were successful, or should I stop until >MGS is back to nominal. Unless the Project asks us to look for the signal, I'd vote to discontinue operations until the spacecraft shows some signs of returning to normal. Kerri is still missing an e-mail for the DSS45 pass on 058, before the anomaly. -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Fri Mar 1 01:24:22 2002 Date: Thu, 28 Feb 2002 19:49:40 GMT From: aseel anabtawi To: Kusza@magellan.stanford.edu, aseel@rsops2.fltops.jpl.nasa.gov, rsimpson@magellan.stanford.edu Subject: More on the Anomaly Hello, Below is a forward from Steve Odiorne. I'm not including the attachment that he mentions at the beginning since it doesn't cover the anomaly. I thought that you may want to use some of the info for the Health Report. -Aseel >From: "Odiorne, Stephen C" >Subject: MGS Status Report 2/27/02 >Date: Thu, 28 Feb 2002 11:51:16 -0700 > >The attached status report covers MGS status up to 1900 UTC, 2/27/02. Up to >that time MGS was nominal. At 1854 UTC, we sent commands to update the gyro >scale factor, just like we did last week. Updating the scale factor >requires disabling and re-enabling star processing. Whenever star >processing is enabled, the tolerances for identifying stars are loosened >until stars are identified, then they automatically tighten. This leaves a >small window of opportunity for STAREX (the star processing software) to >misidentify a star and corrupt attitude knowledge. We think this is what >has happened to MGS. We have lost contact with MGS downlink since >yesterday, 2/27/02 at 2220 UTC. We believe that the attitude knowledge has >been corrupted enough to degrade pointing by 2 to 5 degrees. This is large >enough to lose the downlink, but small enough that the spacecraft has not >automatically entered Contingency-mode. We are in the process of commanding >the spacecraft into C-mode so we can regain downlink and use our C-mode >recovery procedure to bring MGS back to nominal status. > > <> > >Steve Odiorne >LMAO MGS Spacecraft Engineer >E-mail: stephen.c.odiorne@lmco.com >Phone: (303) 977-7960 >Pager: (720) 521-5362 -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Thu Feb 28 18:03:31 2002 Date: Thu, 28 Feb 2002 04:50:01 GMT From: aseel anabtawi To: aseel.anabtawi@jpl.nasa.gov, data@magellan.stanford.edu, joe@neptune.stanford.edu, kusza@magellan.stanford.edu, rsimpson@magellan.stanford.edu DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13298 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-21:11:00 End Record: 2002/058-21:20:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13298 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-22:30:00 End Record: 2002/058-22:38:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13299 Occultation Sense: e SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/058-23:08:00 End Record: 2002/058-23:17:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13299 Occultation Sense: i SOE: mm158b.31.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-00:28:00 End Record: 2002/059-00:37:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13300 Occultation Sense: e SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-01:06:00 End Record: 2002/059-01:15:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13300 Occultation Sense: i SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-02:25:00 End Record: 2002/059-02:34:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13301 Occultation Sense: e SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-03:04:00 End Record: 2002/059-03:13:00 DSS: 15 RSR: RSR2A Subchannel: 1 Orbit Number: 13301 Occultation Sense: i SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-04:23:00 End Record: 2002/059-04:32:00 From Eugene.E.Brower@jpl.nasa.gov Wed Feb 27 22:09:43 2002 Received: from eis-msg-012.jpl.nasa.gov (eis-msg-012.jpl.nasa.gov [137.78.160.40]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id g1S69h505140 for ; Wed, 27 Feb 2002 22:09:43 -0800 (PST) Received: from [137.78.144.239] (dhcp-78-144-239.jpl.nasa.gov [137.78.144.239]) by eis-msg-012.jpl.nasa.gov (8.12.1/8.12.1) with ESMTP id g1S69col029734; Wed, 27 Feb 2002 22:09:39 -0800 (PST) Mime-Version: 1.0 X-Sender: ebrower@pop.jpl.nasa.gov Message-Id: X-Priority: 1 (Highest) Date: Wed, 27 Feb 2002 22:09:34 -0800 To: MGS Dist:; From: Gene Brower Subject: MGS Anomaly Status Content-Type: multipart/alternative; boundary="============_-1197245917==_ma============" Content-Length: 4319 Status: RO --============_-1197245917==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" ALL, MGS downlink carrier signal started to degrade then was lost on Wednesday February 27. At approximately 02-058/19:24 (SCET) after a new Y-axis Gyro scale factor update was uploaded and a STAREX reset (part of the scale factor update process) was commanded. At this time the star identification process began to show convergence problema and unidentified star counter started to incremented displaying higher than normal values. When the downlink signal was expected to return after occultation, AGC levels were lower than expected and telemetry became limited. The downlink signal continued to degrade to the point the carrier signal was not seen by the DSN stations (Both 34-meter and 70-meter). When the initial star processing problems first were noticed, contingency commands were built to command the spacecraft to the nadir orientation, so that MHSA inputs could be included in the attitude determination. Commands to return to nadir were radiated numerous times over both 34-meter and 70- meter DSN stations but these command were unable to be confirmed received by the spacecraft. With lack of downlink carrier signal and after continued attempts to return MGS to a nadir orientation a decision was made to stop commanding MGS in the hopes that the problem would correct the error autonomously or MGS would enter C-mode. On Thursday morning at 7:30 am (Pacific) a status meeting to discuss recovery options will be held on the MGS MeetMe line 818-393-4544. Thank You, Gene Brower Mars Global Surveyor Mission Manager M/S: 264-235, Office: 264-212 Phone: OFFICE: (818)393-0943 CELL: (818)645-5943 --============_-1197245917==_ma============ Content-Type: text/html; charset="us-ascii" MGS Anomaly Status
ALL,

MGS downlink carrier signal started to degrade then was lost on Wednesday February 27. 
At approximately 02-058/19:24 (SCET) after a new Y-axis Gyro scale factor update was uploaded and a STAREX reset (part of the scale factor update process) was commanded. At this time the star identification process began to show convergence problema and unidentified star counter started to incremented displaying higher than normal values.  When the downlink signal was expected to return after occultation, AGC levels were lower than expected and telemetry became limited. The downlink signal continued to degrade to the point the carrier signal was not seen by the DSN stations (Both 34-meter and 70-meter).
 
When the initial star processing problems first were noticed, contingency commands were built to command the spacecraft to the nadir orientation, so that MHSA inputs could be included in the attitude determination.  Commands to return to nadir were radiated numerous times over both 34-meter and 70- meter DSN stations but these command were unable to be confirmed received by the spacecraft.  With lack of downlink carrier signal and after continued attempts to return MGS to a nadir orientation a decision was made to stop commanding MGS in the hopes that the problem would correct the error autonomously or MGS would enter C-mode.

On Thursday morning at 7:30 am (Pacific) a status meeting to discuss recovery options will be held on the MGS MeetMe line 818-393-4544.


Thank You,

Gene Brower <ebrower@jpl.nasa.gov>
Mars Global Surveyor Mission Manager
M/S: 264-235, Office: 264-212
Phone:     OFFICE: (818)393-0943
        CELL: (818)645-5943
--============_-1197245917==_ma============-- -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Thu Feb 28 11:17:20 2002 Received: from thorn.fltops.jpl.nasa.gov (thorn.fltops.jpl.nasa.gov [137.228.90.10]) by magellan.stanford.edu (8.11.6/8.11.6) with SMTP id g1SJHJ510845; Thu, 28 Feb 2002 11:17:19 -0800 (PST) Received: by thorn.fltops.jpl.nasa.gov; id LAA16026; Thu, 28 Feb 2002 11:17:20 -0800 Received: from airmail.fltops.jpl.nasa.gov(137.228.96.12) by thorn.fltops.jpl.nasa.gov via smap (V4.2) id xma015923; Thu, 28 Feb 02 11:17:03 -0800 Received: from rsops2.fltops.jpl.nasa.gov (rsops2.fltops.jpl.nasa.gov [137.228.136.22]) by airmail.fltops.jpl.nasa.gov (8.9.3+Sun/8.9.3) with ESMTP id LAA20902; Thu, 28 Feb 2002 11:16:59 -0800 (PST) Received: (from aseel@localhost) by rsops2.fltops.jpl.nasa.gov (8.9.3+Sun/8.9.3) id TAA23316; Thu, 28 Feb 2002 19:17:03 GMT Date: Thu, 28 Feb 2002 19:17:03 GMT From: aseel anabtawi Message-Id: <200202281917.TAA23316@rsops2.fltops.jpl.nasa.gov> To: Kusza@magellan.stanford.edu, Sami.W.Asmar@jpl.nasa.gov, aseel@rsops2.fltops.jpl.nasa.gov, hinson@rocc.stanford.edu, joe@nova.stanford.edu, len@nova.stanford.edu, rsimpson@magellan.stanford.edu Subject: Fwd: MGS Anomaly Status Content-Length: 2012 Status: RO The last successful measurement was 13297i over DSS-65. 13298e over DSS-65 and DSS-15 had a very weak signal, and so did 13298i over DSS-15. All measurements that followed had no signal. >From: Gene Brower >To: MGS Dist:; >Subject: MGS Anomaly Status >Date: Wed, 27 Feb 2002 22:09:34 -0800 > >ALL, > >MGS downlink carrier signal started to degrade then was lost on >Wednesday February 27. > >At approximately 02-058/19:24 (SCET) after a new Y-axis Gyro scale >factor update was uploaded and a STAREX reset (part of the scale >factor update process) was commanded. At this time the star >identification process began to show convergence problema and >unidentified star counter started to incremented displaying higher >than normal values. When the downlink signal was expected to return >after occultation, AGC levels were lower than expected and telemetry >became limited. The downlink signal continued to degrade to the >point >the carrier signal was not seen by the DSN stations (Both 34-meter >and 70-meter). > >When the initial star processing problems first were noticed, >contingency commands were built to command the spacecraft to the >nadir orientation, so that MHSA inputs could be included in the >attitude determination. Commands to return to nadir were radiated >numerous times over both 34-meter and 70- meter DSN stations but >these command were unable to be confirmed received by the >spacecraft. >With lack of downlink carrier signal and after continued attempts to >return MGS to a nadir orientation a decision was made to stop >commanding MGS in the hopes that the problem would correct the error >autonomously or MGS would enter C-mode. > >On Thursday morning at 7:30 am (Pacific) a status meeting to discuss >recovery options will be held on the MGS MeetMe line 818-393-4544. > > >Thank You, > >Gene Brower >Mars Global Surveyor Mission Manager >M/S: 264-235, Office: 264-212 >Phone: OFFICE: (818)393-0943 > CELL: (818)645-5943 -------------------------------------------------------------------------- From aseel@airmail.fltops.jpl.nasa.gov Thu Feb 28 11:50:38 2002 Received: from thorn.fltops.jpl.nasa.gov (thorn.fltops.jpl.nasa.gov [137.228.90.10]) by magellan.stanford.edu (8.11.6/8.11.6) with SMTP id g1SJoc511148; Thu, 28 Feb 2002 11:50:38 -0800 (PST) Received: by thorn.fltops.jpl.nasa.gov; id LAA03355; Thu, 28 Feb 2002 11:50:38 -0800 Received: from airmail.fltops.jpl.nasa.gov(137.228.96.12) by thorn.fltops.jpl.nasa.gov via smap (V4.2) id xma002805; Thu, 28 Feb 02 11:49:40 -0800 Received: from rsops2.fltops.jpl.nasa.gov (rsops2.fltops.jpl.nasa.gov [137.228.136.22]) by airmail.fltops.jpl.nasa.gov (8.9.3+Sun/8.9.3) with ESMTP id LAA21323; Thu, 28 Feb 2002 11:49:35 -0800 (PST) Received: (from aseel@localhost) by rsops2.fltops.jpl.nasa.gov (8.9.3+Sun/8.9.3) id TAA23411; Thu, 28 Feb 2002 19:49:40 GMT Date: Thu, 28 Feb 2002 19:49:40 GMT From: aseel anabtawi Message-Id: <200202281949.TAA23411@rsops2.fltops.jpl.nasa.gov> To: Kusza@magellan.stanford.edu, aseel@rsops2.fltops.jpl.nasa.gov, rsimpson@magellan.stanford.edu Subject: More on the Anomaly Content-Length: 1636 Status: RO Hello, Below is a forward from Steve Odiorne. I'm not including the attachment that he mentions at the beginning since it doesn't cover the anomaly. I thought that you may want to use some of the info for the Health Report. -Aseel >From: "Odiorne, Stephen C" >Subject: MGS Status Report 2/27/02 >Date: Thu, 28 Feb 2002 11:51:16 -0700 > >The attached status report covers MGS status up to 1900 UTC, 2/27/02. Up to >that time MGS was nominal. At 1854 UTC, we sent commands to update the gyro >scale factor, just like we did last week. Updating the scale factor >requires disabling and re-enabling star processing. Whenever star >processing is enabled, the tolerances for identifying stars are loosened >until stars are identified, then they automatically tighten. This leaves a >small window of opportunity for STAREX (the star processing software) to >misidentify a star and corrupt attitude knowledge. We think this is what >has happened to MGS. We have lost contact with MGS downlink since >yesterday, 2/27/02 at 2220 UTC. We believe that the attitude knowledge has >been corrupted enough to degrade pointing by 2 to 5 degrees. This is large >enough to lose the downlink, but small enough that the spacecraft has not >automatically entered Contingency-mode. We are in the process of commanding >the spacecraft into C-mode so we can regain downlink and use our C-mode >recovery procedure to bring MGS back to nominal status. > > <> > >Steve Odiorne >LMAO MGS Spacecraft Engineer >E-mail: stephen.c.odiorne@lmco.com >Phone: (303) 977-7960 >Pager: (720) 521-5362 -------------------------------------------------------------------------- From joe@neptune.stanford.edu Mon Mar 18 16:20:53 2002 Received: from nova.Stanford.EDU (nova [171.64.90.123]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id g2J0Kro15763 for ; Mon, 18 Mar 2002 16:20:53 -0800 (PST) Received: from neptune.Stanford.EDU (neptune.Stanford.EDU [171.64.90.149]) by nova.Stanford.EDU (8.9.3/8.9.3) with ESMTP id QAA04974; Mon, 18 Mar 2002 16:21:15 -0800 (PST) Received: from localhost (joe@localhost) by neptune.Stanford.EDU (8.11.6/8.11.6) with ESMTP id g2J0K3o10236; Mon, 18 Mar 2002 16:20:03 -0800 (PST) Message-Id: <200203190020.g2J0K3o10236@neptune.Stanford.EDU> X-Mailer: exmh version 2.0.2 2/24/98 From: Joe Twicken To: hinson@nova.stanford.edu, joe@nova.stanford.edu, rsimpson@nova.stanford.edu Subject: Re: RSR Notice: /users/z08/procRSR/20772312 In-reply-to: Your message of "Mon, 18 Mar 2002 15:35:48 PST." <200203182335.g2INZmo15174@magellan.stanford.edu> References: <200203182335.g2INZmo15174@magellan.stanford.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 18 Mar 2002 16:20:03 -0800 Sender: joe@neptune.stanford.edu Content-Length: 1505 Status: RO (1) There was no HGA motion compensation for these recordings >20580055.RSR p 15XR1IRXN101 15XR1IC1XX01 15XR1IF1S101 15XR1IS1T101 15XR1IS1T201 15XR1IS1T301 15XR1IS1T401 15XR1IS1T501 >20580133.RSR p 15XR1ERXN101 15XR1EC1XX01 15XR1EF1S101 15XR1ES1T101 15XR1ES1T201 15XR1ES1T301 15XR1ES1T401 15XR1ES1T501 >20580253.RSR p 45XR1IRXN101 45XR1IC1XX01 45XR1IF1S101 45XR1IS1T101 45XR1IS1T201 45XR1IS1T301 45XR1IS1T401 45XR1IS1T501 >20580331.RSR p 45XR1ERXN101 45XR1EC1XX01 45XR1EF1S101 45XR1ES1T101 45XR1ES1T201 45XR1ES1T301 45XR1ES1T401 45XR1ES1T501 >20580450.RSR p 45XR1IRXN101 45XR1IC1XX01 45XR1IF1S101 45XR1IS1T101 45XR1IS1T201 45XR1IS1T301 45XR1IS1T401 45XR1IS1T501 >20580529.RSR p 45XR1ERXN101 45XR1EC1XX01 45XR1EF1S101 45XR1ES1T101 45XR1ES1T201 45XR1ES1T301 45XR1ES1T401 45XR1ES1T501 >20580648.RSR p 45XR1IRXN101 45XR1IC1XX01 45XR1IF1S101 45XR1IS1T101 45XR1IS1T201 45XR1IS1T301 45XR1IS1T401 45XR1IS1T501 >20580727.RSR p 45XR1ERXN101 45XR1EC1XX01 45XR1EF1S101 45XR1ES1T101 45XR1ES1T201 45XR1ES1T301 45XR1ES1T401 45XR1ES1T501 >20580846.RSR p 45XR1IRXN101 45XR1IC1XX01 45XR1IF1S101 45XR1IS1T101 45XR1IS1T201 45XR1IS1T301 45XR1IS1T401 45XR1IS1T501 >20580924.RSR p 45XR1ERXN101 45XR1EC1XX01 45XR1EF1S101 45XR1ES1T101 45XR1ES1T201 45XR1ES1T301 45XR1ES1T401 45XR1ES1T501 >20581913.RSR p 65XR1ERXN101 65XR1EC1XX01 65XR1EF1S101 65XR1ES1T101 65XR1ES1T201 65XR1ES1T301 65XR1ES1T401 65XR1ES1T501 >20582032.RSR p 65XR1IRXN101 65XR1IC1XX01 65XR1IF1S101 65XR1IS1T101 65XR1IS1T201 65XR1IS1T301 65XR1IS1T401 65XR1IS1T501 -------------------------------------------------------------------------- From joe@nova.stanford.edu Tue Oct 29 09:34:56 2002 Received: from neptune.Stanford.EDU (neptune [171.64.90.149]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id g9THYss16337 for ; Tue, 29 Oct 2002 09:34:55 -0800 (PST) Received: from neptune.Stanford.EDU (joe@localhost) by neptune.Stanford.EDU (8.11.6/8.11.6) with ESMTP id g9THYq503942; Tue, 29 Oct 2002 09:34:52 -0800 (PST) Message-Id: <200210291734.g9THYq503942@neptune.Stanford.EDU> X-Authentication-Warning: neptune.Stanford.EDU: joe owned process doing -bs X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 From: Joe Twicken To: flemoine@ishtar.gsfc.nasa.gov Cc: rsimpson@magellan.stanford.edu (Dick Simpson 723-3525), hinson@nova.stanford.edu (Dave Hinson) Subject: Re: Gap in GDN Coverage In-reply-to: Your message of "Tue, 29 Oct 2002 15:59:11 GMT." <20021029155912.0D44211B13@ishtar.gsfc.nasa.gov> References: <20021029155912.0D44211B13@ishtar.gsfc.nasa.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 29 Oct 2002 09:34:52 -0800 Content-Length: 1758 Status: O Hello again Frank- Thanks for your reply. I am not sure about the exact timing of the contingency mode. Perhaps Dick has access to more accurate numbers. I believe that our last good occultation recording on 02/27 ended at 20:41 ERT, and our first good recording on 03/07 started at 03:11 ERT. One earlier occultation was recorded on 03/07 but the (egress) occultation was not captured. If you could fill in this gap, that would be great. Thanks again... Joe > Hi Joe > Yes, we did not do orbits due to the contigency mode. > Yes, i can look into extending the orbits to 02/27 > and restart earlier on 03/07. > It would help to know when the spacecraft entered > and exited CMode - My event master file lists the times > as 2002/02/27 20:00 to 03/07 23:00 - but those times > I think are only approximate. > > What time of day on 03/07 and 02/27 are your occultation > passes? That will also help to decide how to set up > the fill-in orbits. > >Frank- > >> >> Hello Frank- >> >> There appears to be a gap in GDN coverage between your >> gdn_ql18_202191945_202260110.tsp (our 2050057A.GDN) and >> gdn_ql18_203072300_203130110.tsp (our 2066072A.GDN) files. >> >> We have open loop occultation data for the dates 2002/57-58 >> (2002/02/26-27) and also for the date 2002/066 (2002/03/07). >> Almost all of this open loop data falls in the gap between >> your two files. The spacecraft was in contingency mode from >> the end of 2002/58 through 2002/065. Do you have another trajectory >> reconstruction file that fills in the part of the gap when the >> spacecraft was not in C-mode, or is there some reason why you >> have not reconstructed the orbits for those dates? >> >> Thanks much... >> >> Joe >> >> >> > -------------------------------------------------------------------------- From rsimpson@magellan.stanford.edu Tue Oct 29 10:05:21 2002 Received: (from rsimpson@localhost) by magellan.stanford.edu (8.11.6/8.11.6) id g9TI5Ju21232; Tue, 29 Oct 2002 10:05:19 -0800 (PST) Date: Tue, 29 Oct 2002 10:05:19 -0800 (PST) From: Dick Simpson 723-3525 Message-Id: <200210291805.g9TI5Ju21232@magellan.stanford.edu> To: flemoine@ishtar.gsfc.nasa.gov, joe@nova.stanford.edu Subject: Re: Gap in GDN Coverage Cc: hinson@nova.stanford.edu, rsimpson@magellan.stanford.edu Content-Length: 1155 Status: R >I believe that our last good occultation recording on 02/27 ended at 20:41 >ERT, and our first good recording on 03/07 started at 03:11 ERT. One earlier >occultation was recorded on 03/07 but the (egress) occultation was not >captured. Joe is correct. The occultation ending at 2002-02-27T20:41:00 was an ingress. The SNR was down by about 3 dB, but not necessarily something to worry about. 30 minutes later, on egress, the spacecraft had entered C-mode. There was very little signal for the next several hours. It appears the normal carrier link was re-established on 2002-03-05 at about 23:00. Occultations (and probably other normal science operations) resumed shortly after midnight on 2002-03-07. Our first occultation recording began at 01:53; but, as Joe notes, we may have missed the egress itself for other reasons. I'm guessing there is good tracking data up to 2002-02-27T20:41:00 (give or take a few minutes for the occultation). And there MAY be tracking data as early as 2002-03-05T23:00:00; but we don't need orbits until at least 2002-03-07T01:53:00. All times are Earth Receive Time (UTC). -------------------------------------------------------------------------- From joe@nova.stanford.edu Tue Nov 12 21:41:01 2002 Received: from neptune.Stanford.EDU (neptune [171.64.90.149]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id gAD5f0F23868 for ; Tue, 12 Nov 2002 21:41:00 -0800 (PST) Received: from neptune.Stanford.EDU (joe@localhost) by neptune.Stanford.EDU (8.11.6/8.11.6) with ESMTP id gAD5fL713074; Tue, 12 Nov 2002 21:41:21 -0800 (PST) Message-Id: <200211130541.gAD5fL713074@neptune.Stanford.EDU> X-Authentication-Warning: neptune.Stanford.EDU: joe owned process doing -bs X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 From: Joe Twicken To: flemoine@ishtar.gsfc.nasa.gov cc: rsimpson@magellan.stanford.edu, hinson@nova.stanford.edu (Dave Hinson) Subject: Re: spk file In-reply-to: Your message of "Tue, 12 Nov 2002 18:20:14 GMT." <20021112182014.C79E111B1E@ishtar.gsfc.nasa.gov> References: <20021112182014.C79E111B1E@ishtar.gsfc.nasa.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 12 Nov 2002 21:41:20 -0800 Content-Length: 753 Status: RO Hi Frank- Thanks for producing this file. The stop time (20:58) looks fine. We should be able to process all of the good occultation data that was collected on 02/27 with this file. Thanks again... Joe >Joe and Dick- > >gdn_ql18_202232100_202272100.tsp.Z is on the geodesy anonftp site; > >Is the stop time satisfactory? The 2-way tracking data cut out >before 2035 on 02/27 - although there is one-way data afterward. > >We are doing the arc on the other end of the C-Mode but had >to fix a quaternion fill-in problem first. It seems the s/c >was not in pitch 16 degree mode when it first exited C-Mode, >but rather nadir pointing until about 2002 Mar 08 23:26:50ish -so >my quaternion fill-in program had to be altered accordingly. > >Frank- -------------------------------------------------------------------------- From joe@nova.stanford.edu Thu Dec 12 20:54:08 2002 Received: from nova.Stanford.EDU (nova [171.64.90.123]) by magellan.stanford.edu (8.11.6/8.11.6) with ESMTP id gBD4s8v14127 for ; Thu, 12 Dec 2002 20:54:08 -0800 (PST) Received: from neptune.Stanford.EDU (neptune.Stanford.EDU [171.64.90.149]) by nova.Stanford.EDU (8.9.3/8.9.3) with ESMTP id UAA16409; Thu, 12 Dec 2002 20:54:19 -0800 (PST) Received: from neptune.Stanford.EDU (joe@localhost) by neptune.Stanford.EDU (8.11.6/8.11.6) with ESMTP id gBD4sIq10864; Thu, 12 Dec 2002 20:54:18 -0800 (PST) Message-Id: <200212130454.gBD4sIq10864@neptune.Stanford.EDU> X-Authentication-Warning: neptune.Stanford.EDU: joe owned process doing -bs X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 From: Joe Twicken To: hinson@nova.stanford.edu, joe@nova.stanford.edu, rsimpson@nova.stanford.edu Subject: Re: RSR Notice: /users/z13/procRSR/23461915 In-reply-to: Your message of "Thu, 12 Dec 2002 12:12:21 PST." <200212122012.gBCKCLg26918@magellan.stanford.edu> References: <200212122012.gBCKCLg26918@magellan.stanford.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 12 Dec 2002 20:54:18 -0800 Content-Length: 1790 Status: RO (1) Reprocessed with Goddard trajectory. This GDN file was generated specifically to include orbits prior to an MGS contingency mode period which were not previously reconstructed (2) The Allan deviation was high for the 20580253.RSR (1.7e-12 at 4 seconds), 20580331.RSR (1.6e-12 at 4 seconds) and 20580450.RSR (1.1e-12 at 4 seconds) >20580055.RSR p 15XR1IRXN102 15XR1IC1XX02 15XR1IF1S102 15XR1IS1T102 15XR1IS1T202 15XR1IS1T302 15XR1IS1T402 15XR1IS1T502 >20580133.RSR p 15XR1ERXN102 15XR1EC1XX02 15XR1EF1S102 15XR1ES1T102 15XR1ES1T202 15XR1ES1T302 15XR1ES1T402 15XR1ES1T502 >20580253.RSR p 45XR1IRXN102 45XR1IC1XX02 45XR1IF1S102 45XR1IS1T102 45XR1IS1T202 45XR1IS1T302 45XR1IS1T402 45XR1IS1T502 >20580331.RSR p 45XR1ERXN102 45XR1EC1XX02 45XR1EF1S102 45XR1ES1T102 45XR1ES1T202 45XR1ES1T302 45XR1ES1T402 45XR1ES1T502 >20580450.RSR p 45XR1IRXN102 45XR1IC1XX02 45XR1IF1S102 45XR1IS1T102 45XR1IS1T202 45XR1IS1T302 45XR1IS1T402 45XR1IS1T502 >20580529.RSR p 45XR1ERXN102 45XR1EC1XX02 45XR1EF1S102 45XR1ES1T102 45XR1ES1T202 45XR1ES1T302 45XR1ES1T402 45XR1ES1T502 >20580648.RSR p 45XR1IRXN102 45XR1IC1XX02 45XR1IF1S102 45XR1IS1T102 45XR1IS1T202 45XR1IS1T302 45XR1IS1T402 45XR1IS1T502 >20580727.RSR p 45XR1ERXN102 45XR1EC1XX02 45XR1EF1S102 45XR1ES1T102 45XR1ES1T202 45XR1ES1T302 45XR1ES1T402 45XR1ES1T502 >20580846.RSR p 45XR1IRXN102 45XR1IC1XX02 45XR1IF1S102 45XR1IS1T102 45XR1IS1T202 45XR1IS1T302 45XR1IS1T402 45XR1IS1T502 >20580924.RSR p 45XR1ERXN102 45XR1EC1XX02 45XR1EF1S102 45XR1ES1T102 45XR1ES1T202 45XR1ES1T302 45XR1ES1T402 45XR1ES1T502 >20581913.RSR p 65XR1ERXN102 65XR1EC1XX02 65XR1EF1S102 65XR1ES1T102 65XR1ES1T202 65XR1ES1T302 65XR1ES1T402 65XR1ES1T502 >20582032.RSR p 65XR1IRXN102 65XR1IC1XX02 65XR1IF1S102 65XR1IS1T102 65XR1IS1T202 65XR1IS1T302 65XR1IS1T402 65XR1IS1T502