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 2002/059." END_OBJECT = TEXT END 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 18:03:41 2002 Date: Thu, 28 Feb 2002 10:00:01 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: 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 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13302 Occultation Sense: e SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-05:02:00 End Record: 2002/059-05:11:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13302 Occultation Sense: i SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-06:21:00 End Record: 2002/059-06:29:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13303 Occultation Sense: e SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-07:00:00 End Record: 2002/059-07:08:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13303 Occultation Sense: i SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-08:19:00 End Record: 2002/059-08:27:00 DSS: 45 RSR: RSR2A Subchannel: 1 Orbit Number: 13304 Occultation Sense: e SOE: mm159a.08.tsoe Ground Mode: 1 Uplink Station: -- Sampling Rate: 2K Bit Resolution: 16 Begin Record: 2002/059-08:57:00 End Record: 2002/059-09:06:00 -------------------------------------------------------------------------- From Eugene.E.Brower@jpl.nasa.gov Thu Feb 28 11:55:25 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 g1SJtO511155 for ; Thu, 28 Feb 2002 11:55:24 -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 g1SJtJol012193; Thu, 28 Feb 2002 11:55:20 -0800 (PST) Mime-Version: 1.0 X-Sender: ebrower@pop.jpl.nasa.gov Message-Id: Date: Thu, 28 Feb 2002 11:55:14 -0800 To: MGS Dist:; From: Gene Brower Subject: MGS Anomaly Status Update Content-Type: text/plain; charset="us-ascii" ; format="flowed" Content-Length: 213 Status: RO ALL: Commands to put MGS into C-mode have been radiated but no signal has been seen at DSS 65 or DSS 63 as of Noon Pacific (Thursday Feb. 28). We will continue to contact MGS over DSS 14 this afternoon. -Gene -------------------------------------------------------------------------- From Eugene.E.Brower@jpl.nasa.gov Thu Feb 28 17:12:41 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 g211Cf525147 for ; Thu, 28 Feb 2002 17:12:41 -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 g211Caol017582; Thu, 28 Feb 2002 17:12:36 -0800 (PST) Mime-Version: 1.0 X-Sender: ebrower@pop.jpl.nasa.gov Message-Id: Date: Thu, 28 Feb 2002 17:12:34 -0800 To: MGS Dist:; From: Gene Brower Subject: MGS Anomaly Status Update Content-Type: multipart/alternative; boundary="============_-1197177340==_ma============" Content-Length: 1514 Status: RO --============_-1197177340==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" ALL: We continue to have no success in commanding MGS into C-mode over the DSS 14 support Thursday afternoon. We will continue to acquire MGS over DSS 43 this evening with the best chance of communicate with MGS around the 060/0430z time frame thanks to a telecom configuration change in the background sequence. Next status meeting will be help on Friday morning at 8:30 am (Pacific) on the MGS MeetMe line 818-393-4544. -Gene --============_-1197177340==_ma============ Content-Type: text/html; charset="us-ascii" MGS Anomaly Status Update
ALL:
We continue to have no success in commanding MGS into C-mode over the DSS 14 support Thursday afternoon.  We will continue to acquire MGS over DSS 43 this evening with the best chance of communicate with MGS around the 060/0430z time frame thanks to a telecom configuration change in the background sequence.

Next status meeting will be help on Friday morning at 8:30 am (Pacific) on the MGS MeetMe line 818-393-4544.


-Gene
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