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 2001/292." END_OBJECT = TEXT END From aseel@godzilla.jpl.nasa.gov Mon Oct 22 16:01 PDT 2001 Received: from godzilla.jpl.nasa.gov (godzilla.jpl.nasa.gov [137.78.177.120]) by magellan.stanford.edu (8.9.3/8.9.3) with ESMTP id QAA26711; Mon, 22 Oct 2001 16:01:32 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by godzilla.jpl.nasa.gov (8.9.3/8.9.3) with SMTP id QAA21412; Mon, 22 Oct 2001 16:02:31 -0700 (PDT) Message-Id: <200110222302.QAA21412@godzilla.jpl.nasa.gov> Date: Mon, 22 Oct 2001 16:02:31 -0700 (PDT) From: Aseel Anabtawi Reply-To: Aseel Anabtawi Subject: Re: MGS RST Rpt HEA1295A.TXT To: rsimpson@magellan.stanford.edu Cc: data@magellan.stanford.edu, hinson@nimbus.stanford.edu, joe@neptune.stanford.edu, sami.asmar@jpl.nasa.gov, jglance@mail1.jpl.nasa.gov MIME-Version: 1.0 Content-MD5: 2L1DvLyF7jqpD3gQoFazzw== X-Mailer: dtmail 1.2.1 CDE Version 1.2.1 SunOS 5.6 sun4u sparc Content-Type: TEXT/plain; charset=us-ascii Content-Length: 4316 Status: RO Dick, I thought you were on Gene Brower's distribution list, so I didn't forward the messages to you. Sorry! Below are Gene's emails since Friday. -Aseel ------------- Begin Forwarded Message ------------- Date: Fri, 19 Oct 2001 07:27:43 -0700 To: MGS Dist:; From: Gene Brower Subject: MGS in C-Mode FYI: MGS is currently in C-Mode. The preliminary cause seems to be a Starex convergence problem but due to the lack of telemetry the actual root cause is still under investigation. Stay tuned. Thanks -Gene OFFICE: (818)393-0943 CELL: (818)645-5943 ------------- End Forwarded Message ------------- ------------- Begin Forwarded Message ------------- Date: Fri, 19 Oct 2001 09:57:23 -0700 To: MGS Dist:; From: Gene Brower Subject: MGS Status (C-mode) ALL: To keep everyone informed, the current plan for MGS recovery is to attempt to have MGS recovered by Monday, October 22. Currently Telemetry data is sparse due to Sun Coning and the intermittent 10 bps downlink. This first steps will be to stop the Sun coning at a point were continuos telemetry lock can be obtain. Next MRO's will be requested to determine the cause of the C-mode entry. At this point a meeting will be called so the health and safety of MGS can be address prior to taking the next steps in the recovery process. Currently no time is set for this initial meeting. Thank You, Gene Brower ------------- End Forwarded Message ------------- ------------- Begin Forwarded Message ------------- Date: Sun, 21 Oct 2001 21:29:00 -0700 To: MGS Dist:; From: Gene Brower Subject: MGS Recovered The MGS Spacecraft has recovered from the latest Contingency mode entry. MGS will be in the Relay16 Mapping configuration with a nominal Back-Ground Sequence executing at approximately 01-295/0515z (Sunday 10:15 PM Pacific). All Spacecraft Subsystems are operating within expected states. The MGS spacecraft entered contingency mode 2001-292T04:52:18z. Symptoms of spacecraft slowly drifting off point could be seen in the degradation of the downlink AGC after the spacecraft return from a ROTO observation at approximately 292/00:40z. No unusual spacecraft activity (sequences) or uplinks were taking place at the time of entry. Based on the latest available data, this contingency mode entry is similar to the contingency mode entry of September 6, 2001. On September 6 an uncataloged celestial body seemed to interfered with STAREX processing following a ROTO. If STAREX misidentifies a star during the period the attitude covariances are widened to aid the bias convergence process following a ROTO, the gyro biases may get corrupted leading to difficulties in determining attitude knowledge and subsequent contingency mode entry. Upon Contingency mode entry the spacecraft enters sun coning with Low Gain Antenna at a 10bps downlink telemetry rate after each occultation. Contingency mode recovery process began Friday morning October 19 once the downlink signal from MGS were acquired and Contingency mode sun coning was confirmed. Inertial reference was reestablished by the end of the day Friday which confirm no long term anomalies with STAREX. MGS then established NADIR point and resumed nominal HGA tracking at approximately at 294/00:22z (Saturday October 20 at 5:22 PM Pacific) The TES and MOC science instruments were Power on Sunday afternoon October 21. A nominal Back-Ground Sequence was set to begin executing at approximately 01-295/0500z (Sunday 10:00 PM Pacific) The MOLA instrument will be turned on as part of the Back-Ground Sequence Monday night and MAG/ER instruments will be powered on sometime next week following the Mars Odyssey MOI activities. Thank You, Gene Brower ------------- End Forwarded Message ------------- > > MGS went into C-mode on Friday. When I asked they thought > it was related to a ROTO activity. > > > At 03:35 PM 10/22/2001 -0700, Dick Simpson 723-3525 wrote: > > > >According to Data Control, MGS is just coming out of contingency mode -- > >hence our 0.5 MB of spacecraft engineering data from day 293 (as opposed > >to about 25 MB normally). Anyone know anything about this? > > -------------------------------------------------------------------------- From flemoine@geodesy2.gsfc.nasa.gov Tue Oct 23 15:57 PDT 2001 Received: from geodesy2.gsfc.nasa.gov (geodesy2.gsfc.nasa.gov [128.183.107.54]) by magellan.stanford.edu (8.9.3/8.9.3) with ESMTP id PAA14206 for ; Tue, 23 Oct 2001 15:57:18 -0700 (PDT) Received: (from flemoine@localhost) by geodesy2.gsfc.nasa.gov (8.9.3/8.9.3) id WAA16290 for rsimpson@magellan.stanford.edu; Tue, 23 Oct 2001 22:58:18 GMT From: Frank Lemoine Message-Id: <200110232258.WAA16290@geodesy2.gsfc.nasa.gov> Subject: [Fwd: MGS Recovered] (forwarded) To: rsimpson@magellan.stanford.edu Date: Tue, 23 Oct 2001 22:58:18 GMT X-Mailer: Elm [revision: 212.4] Content-Type: text Content-Length: 2874 Status: RO > > Mime-Version: 1.0 > X-Sender: ebrower@pop.jpl.nasa.gov > Message-Id: > Date: Sun, 21 Oct 2001 21:29:00 -0700 > To: MGS Dist:; > From: Gene Brower > Subject: MGS Recovered > Cc: David.A.Spencer@jpl.nasa.gov, Chris.P.Jones@jpl.nasa.gov, > Matthew.R.Landano@jpl.nasa.gov > Content-Type: text/plain; charset="us-ascii" ; format="flowed" > X-Mozilla-Status2: 00000000 > > > The MGS Spacecraft has recovered from the latest Contingency mode entry. > > MGS will be in the Relay16 Mapping configuration with a nominal > Back-Ground Sequence executing at approximately 01-295/0515z (Sunday > 10:15 PM Pacific). All Spacecraft Subsystems are operating within > expected states. > > The MGS spacecraft entered contingency mode 2001-292T04:52:18z. > Symptoms of spacecraft slowly drifting off point could be seen in the > degradation of the downlink AGC after the spacecraft return from a > ROTO observation at approximately 292/00:40z. No unusual spacecraft > activity (sequences) or uplinks were taking place at the time of > entry. > > Based on the latest available data, this contingency mode entry is > similar to the contingency mode entry of September 6, 2001. On > September 6 an uncataloged celestial body seemed to interfered with > STAREX processing following a ROTO. If STAREX misidentifies a star > during the period the attitude covariances are widened to aid the > bias convergence process following a ROTO, the gyro biases may get > corrupted leading to difficulties in determining attitude knowledge > and subsequent contingency mode entry. > > Upon Contingency mode entry the spacecraft enters sun coning with Low > Gain Antenna at a 10bps downlink telemetry rate after each > occultation. Contingency mode recovery process began Friday morning > October 19 once the downlink signal from MGS were acquired and > Contingency mode sun coning was confirmed. Inertial reference was > reestablished by the end of the day Friday which confirm no long term > anomalies with STAREX. MGS then established NADIR point and resumed > nominal HGA tracking at approximately at 294/00:22z (Saturday October > 20 at 5:22 PM Pacific) The TES and MOC science instruments were Power > on Sunday afternoon October 21. A nominal Back-Ground Sequence was > set to begin executing at approximately 01-295/0500z (Sunday 10:00 PM > Pacific) The MOLA instrument will be turned on as part of the > Back-Ground Sequence Monday night and MAG/ER instruments will be > powered on sometime next week following the Mars Odyssey MOI > activities. > > > Thank You, > > Gene Brower > Mars Global Surveyor Mission Manager > Genesis PCAT lead (acting-additional duty) > M/S: 264-235, Office: 264-212 > Phone: OFFICE: (818)393-0943 > CELL: (818)645-5943 >