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 2006/352." END_OBJECT = TEXT END From kyle.w.martin@lmco.com Mon Dec 18 11:26:31 2006 Return-Path: Received: from mailgw2a.lmco.com (mailgw2a.lmco.com [192.91.147.7]) by magellan.stanford.edu (8.11.7p2+Sun/8.11.7) with ESMTP id kBIJQUa11480 for ; Mon, 18 Dec 2006 11:26:30 -0800 (PST) Received: from emss03g01.ems.lmco.com (relay3.ems.lmco.com [141.240.4.144])by mailgw2a.lmco.com (LM-6) with ESMTP id kBIJGD3A008860;Mon, 18 Dec 2006 14:16:13 -0500 (EST) Received: from CONVERSION-DAEMON.lmco.com by lmco.com (PMDF V6.3-x3 #31239) id <0JAH00D01HIPX7@lmco.com>; Mon, 18 Dec 2006 14:16:13 -0500 (EST) Received: from EMSS02I00.us.lmco.com ([166.29.2.48]) by lmco.com (PMDF V6.3-x3 #31239) id <0JAH00D01HIIUR@lmco.com> (original mail from kyle.w.martin@lmco.com); Mon, 18 Dec 2006 14:15:54 -0500 (EST) Received: from EMSS02I00.us.lmco.com ([166.29.2.48]) by lmco.com (PMDF V6.3-x3 #31239) with ESMTP id <0JAH006URHCJB7@lmco.com>; Mon, 18 Dec 2006 14:12:30 -0500 (EST) Received: from EMSS02M11.us.lmco.com ([166.29.2.185]) by EMSS02I00.us.lmco.com with Microsoft SMTPSVC(5.0.2195.6713); Mon, 18 Dec 2006 12:12:29 -0700 Date: Mon, 18 Dec 2006 12:12:32 -0700 From: "Martin, Kyle W" Subject: MGS Status - Monday AM (12/18/06) To: "Martin, Kyle W" , "Howell, Dale K" , "Adams, William R" , "Bezjak, Kelly J (N-Red Canyon Software)" , "Delk, John" , "Espitallier, Dean S" , "Gingerich, David E" , "Koch, Lori A" , "Love, Charles R" , "Mumaw, Susan J" , "Odiorne, Stephen C" , "Oliver, Tom H" , "Torkelson, Randy M" , "Travis, Paul A" , "Walthall, Oliver K" , Grant.B.Faris@jpl.nasa.gov, Maria.Schellpfeffer@jpl.nasa.gov, Pasquale.B.Esposito@jpl.nasa.gov, Thomas.E.Thorpe@jpl.nasa.gov, Aseel.Anabtawi@jpl.nasa.gov, jester@osb1.wff.nasa.gov, kcbender@asu.edu, monte.kaelberer@gsfc.nasa.gov, Robert Zimdar , rsimpson@magellan.stanford.edu, sandoval@msss.com, Walter.J.Glance@jpl.nasa.gov, "Zercher, Ray E" , "Starnes, Kenny R" , DSN-MPSETB@jjpl.jpl.nasa.gov, mehall@asu.edu, charles.w.whetsel@jpl.nasa.gov, Sami.W.Asmar@jpl.nasa.gov, Daniel.S.Kahan@jpl.nasa.gov, Bruce.C.Waggoner@jpl.nasa.gov, "Ancheta, Shanti" , JSINCELL@aol.com, "Bendkowski, Barbara A" , "Freund, Sandra" , "Eugene S. Burke" , "Chen, George" , "Donaldson, Jim" , "Herrera, Randy" , "Kahn, Peter" , "Reeves, Glenn E (X-JPL)" , "Slonski, John" , "Stone, Henry" , "Webster, Julie" , "Burt, Brad" , "Manning, Rob" Cc: "Neuman, James C" , "Berry, Robert L" , "Herzl, Al" , "Overman, Brian W" Message-id: <5A2986C73A1DCC4EB5CC1C22D8270009018EEAD8@emss02m11.us.lmco.com> MIME-version: 1.0 X-MIMEOLE: Produced By Microsoft Exchange V6.5 Content-type: multipart/mixed; boundary="Boundary_(ID_dIKHJ7pXOGI4Ru6wviaYpw)" Thread-Topic: MGS Status - Monday AM (12/18/06) Thread-Index: Acb+k0BPmLPx2AYTR0C2wBUnGs71qgDQRa+wAC1UWtAAAVh+AAAwQBEgADLbQwAADt5eQAAiL9EgAASWdoAACZ+BQAApbaxQAAmYrDAAimYbMAANk7ggAC3Xi4AAAKO8sAAAuOqAACjjDTAAyJrFAAGTjjcgADO605AAMHT+gAAJkLKgACpcOoABKyBIQADIR9xAADLxUBAAbCHQUADCOWCw Content-class: urn:content-classes:message X-MS-Has-Attach: yes X-MS-TNEF-Correlator: X-OriginalArrivalTime: 18 Dec 2006 19:12:29.0455 (UTC) FILETIME=[7630F9F0:01C722D8] Content-Length: 51598 Status: RO This is a multi-part message in MIME format. --Boundary_(ID_dIKHJ7pXOGI4Ru6wviaYpw) Content-type: multipart/alternative; boundary="Boundary_(ID_gRyff+J/6op9fhl5gmQ/gQ)" --Boundary_(ID_gRyff+J/6op9fhl5gmQ/gQ) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Still no signal seen from MGS. **** Following is new information discovered this past weekend ************************************************** Over the weekend, Owen (along with Kelly's help in the lab) discovered an error in a general memory load dating back to June 15th of this year that potentially could have led to our present situation. While on SCP-2, there was a desire to synchronize both SCPs in the event the spacecraft was placed back on SCP-1. In evaluating Memory Readouts, a location of 0x2708 was noticed that did not match values in the two SCPs. This location was designated CMODE'HGA'ELE'ANGLE. A Change Request was written and approved on 6/14/06. A general memory load consisting of two data words starting at 0x2708 to sync the two SCPs was uplinked 06-166/11:44:49GMT and confirmed onboard the spacecraft. Spacecraft performance was nominal after this upload. What initiated looking into this general memory load was that Owen noticed the SAM target went beyond the soft stop on 06-166 for the first time and continued for all consecutive orbits. The target was only a degree or so past the soft stop. The only thing that changed on 06-166 was an uplink to resync the SCPs. Looking deeper, he found that mi2014 contained the general memory load as described above. Looking at the Symbol Map, it was noticed that CMODE'HGA'ELE'ANGLE actually began one word earlier - at 0x2707 - not 0x2708. The command should have written the desired two data words to 0x2707 and 0x2708 - NOT 0x2708 and 0x2709. The next question - what is located at 0x2709 - the location of where the 2nd word was written? It is designated SOFT'STOP'ENABLES in the Symbol map. Of the 16 bits of this word, the first 6 are used for enabling/disabling the soft stops on the SAP, SAM and HGA, respectively. The original value had the 6 bits all set to "1" or enabled. The values that were written into this address resulted in disabling of the SAP Ele soft stop, the SAM Azi soft stop, the SAM Ele soft stop and the HGA Azi soft stop. Another consequence is that the CMode elevation angle was corrupted with the incorrect value written into the 2nd of 2 words. Please refer to the attachment. This error did not result into anything noticeable until the 10 degree offset was uplinked and applied to the spacecraft at the beginning of November. On the first rewind during eclipse following the 10 degree offset command receipt, the target put the SAM well past the hard stop and the panel would have hit the hard stop (-123degrees). This was verified in the lab. In STL - the three data words were configured, the 10 degree offset uplinked and on the first eclipse - the spacecraft swapped SAM drives, swapped busses and went into CMode. The lab took 1 orbit to get into CMode where the spacecraft apparently took 2. This can be explained by the nature of how the SAM went into the hard stop and how quickly fault counts accumulated - it obviously can vary. After CMode entry, the spacecraft went to Sun Stuck Gimbal. The HGA positioned itself at 0 degrees in azimuth and -157 degrees in elevation. Basically the HGA was pointed down towards the body, and just slightly towards the +X direction. Several things are still in question: 1. Does the Com pattern "seen" in the first few orbits following the anomaly match this configuration? 2. The Sun Stuck Gimbal attitude is good for power (both arrays on sun), but it does cook the battery in the +Y cavity. Could this explain a lack of power after 5-6-? orbits? 3. Could the SAM break as it drove into the hard stop? 4. Commands were radiated to reassert the HGA 8 days after the anomaly. This should have allowed for proper configuration of the HGA during Sun Com Pwr, yet no signal was seen? As a result of this finding, it was discussed and agreed upon this morning to command the spacecraft to Safe Mode. Initially, we thought we could upload the correct values to the three words described above and then clear the faults. Hopefully, the spacecraft would receive these and the HGA would position itself in the correct position for SCP. After further discussion, it was decided to command the spacecraft to Safe Mode to ensure ALL values required for SAM, SAP and HGA are reasserted. STL was placed in SMode and the HGA subsequently went to the proper position for communications in SCP. The SMode commands were approved at 11:30 MST and we will begin radiating these commands in approximately 1 hour and continue over the next several days. We will command SMode over multiple orbits applying various sweep parameters to cover; 1) changes in frequencies as a result of potential temperature variations and 2) low gain antenna receiver swaps that occur every 100 minutes. There are other areas we will follow up on including process related concerns as the initial June commanding is investigated. We will keep all up to date as information becomes available. ** NEXT TAGUP = Tuesday (12/19) at 09:00 MST, meet-me # = 818-393-4544 ** Thanks. - Kyle Kyle Martin Lockheed Martin Space Exploration Systems Mission Operations - Systems/RTO Team Chief 303-977-6871 work 720-521-7535 pager 303-977-7515 fax Kyle.w.martin@lmco.com