Wednesday, August 8, 2001 (DOY 213/19:00:00 to DOY 220/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1736 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 860 days
Total Mapping Orbits = 10,813
Total Orbits = 12,496
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm151 sequence has performed well since it started on 01-200 (7/19/01). It terminates on 01-227 (8/15/01).
Other - MGS performed the MZ118 Bistatic Radar experiment on 01-217 (8/5/01) and the MZ121 MOLA Diagnostic Test #3 on 01-218 (8/06/01). The spacecraft operated nominally during both events. The Radio Science and MOLA teams are in the process of analyzing the data collected from their respective experiments. The MOLA team was successful in patching the MOLA software to provide higher sampling rates into the data needed to determine what hardware component failed on 01-181 (6/30/01).
Seven more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 165 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.
Uplinks:
There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the Bistatic Radar and MOLA mini-sequences referenced above, and the MZ122 and MZ123 ROTO mini-sequences. 5,532 command files have been radiated to the spacecraft since launch.
Upcoming Events:
On 01-228 (8/16/01) the nominal spacecraft orientation will change. The spacecraft will be commanded to pitch +16 degrees from NADIR in order to better align its attitude with the gravity gradient, thereby reducing fuel consumption and extending spacecraft life.
The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).
Launch / Days since Launch = Nov. 7, 1996 / 1722 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 846 days
Total Mapping Orbits = 10,642
Total Orbits = 12,325
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm151 sequence has performed well since it started on 01-200 (7/19/01). It terminates on 01-227 (8/15/01).
Other - Dust storms spreading across the planet are making narrow angle photographic imaging of Mars impracticable. Therefore, ROTO operations remain suspended until the global dust storms subside. MGS has completed 155 ROTOs to date.
A second in-flight MOLA diagnostic test (MZ116) was performed on 01-206 (7/25/01) to gain more insight into the MOLA anomaly. Detailed analyses will be performed after the recorded data is transmitted to Earth on 01-207 (7/26/01).
Spacecraft Health:
All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.
Uplinks:
There have been 6 uplinks to the spacecraft during the past week, including instrument command loads and the MZ116 MOLA diagnostic test. 5,506 command files have been radiated to the spacecraft since launch.
Upcoming Events:
A Bistatic Radar experiment is planned for 01-217 (8/5/01). The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).
Launch / Days since Launch = Nov. 7, 1996 / 1715 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 839 days
Total Mapping Orbits = 10,556
Total Orbits = 12,239
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm150 sequence has performed well since it started on 01-172 (6/21/01). It terminates on 01-199 (7/18/01). The mm151 sequence, successfully uplinked on 01-197 (7/16/01), begins executing on 01-200 (7/19/01).
Other - Dust storms spreading across the planet are making narrow angle photographic imaging of Mars impracticable. Therefore, ROTO operations remain suspended until the global dust storms subside. MGS has completed 155 ROTOs to date.
An in-flight MOLA diagnostic test (MZ115) was performed on 01-195 (7/14/01) to gain some insight into the MOLA anomaly reported last week. Unfortunately, the MOLA instrument did not assume normal operation, but the data indicate that the MOLA computer is working and that the instrument responds to commanding. We expect further diagnostic testing following the MOLA team's analyses of the most recent data.
Spacecraft Health:
All subsystems report good health and status except for the MOLA payload instrument that malfunctioned on 01-181 (6/30/01). The MOLA instrument team is still investigating the anomaly.
Uplinks:
There have been 13 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the MM151 background sequence, and the MZ115 MOLA diagnostic test. 5,500 command files have been radiated to the spacecraft since launch.
Upcoming Events:
A Bistatic Radar experiment is planned for 01-217 (8/5/01). The first of several Delta-DOR experiments will take place on 01-236 (8/24/01).
Launch / Days since Launch = Nov. 7, 1996 / 1694 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 818 days
Total Mapping Orbits = 10,299
Total Orbits = 11,982
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm150 sequence has performed well since it started on 01-172 (6/21/01). It terminates on 01-199 (7/18/01).
Other - An MGS Mars Relay On-orbit UHF experiment with Stanford University started on 01-177 (6/26/01) and finishes on 01-179 (6/28/01). So far, the experiment has progressed nominally. A more detailed report will be forthcoming following the data analyses.
Eight more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 145 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status.
Uplinks:
There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the mz112 UHF Relay-16 experiment, and ROTO mini-sequences mz111 & mz113. There have been 5,466 command files radiated to the spacecraft since launch.
Upcoming Events:
MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01). A Bistatic Radar Test is planned for 01-217 (8/5/01). More MOLA Polar Scans are scheduled for 01-219 (8/7/01) and 01-220 (8/8/01). Finally, the first of several Delta-DOR experiments will take place on 01-225 (8/13/01).
Launch / Days since Launch = Nov. 7, 1996 / 1687 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 811 days
Total Mapping Orbits = 10,214
Total Orbits = 11,897
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm148 sequence executed successfully from 01-165 (6/14/01) through 01-167 (6/16/01). The mm149 sequence has performed well since it started on 01-168 (6/17/01). It terminates on 01-171 (6/20/01). The mm150 sequence, successfully uplinked on 01-170 (6/19/01), begins executing on 01-172 (6/21/01). The start of mm150 marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Therefore, background command sequences can take advantage of the on-board command scripts originally designed for the nominal mapping mission. 28-day background sequences will become the norm instead of the 3 and 4 day beta-supplement sequences.
Other - Eleven more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 137 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status.
Uplinks:
There have been 12 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz109 & mz110. We also updated Solar Array AEM Script #1 timing to avoid potential electromagnetic interference (EMI) with the solar arrays during HGA transmissions to Earth. There have been 5,449 command files radiated to the spacecraft since launch.
Upcoming Events:
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).
Launch / Days since Launch = Nov. 7, 1996 / 1680 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 804 days
Total Mapping Orbits = 10,129
Total Orbits = 11,812
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm146 sequence executed successfully from 01-158 (6/7/01) through 01-160 (6/09/01). The mm147 sequence has performed well since it started on 01-161 (6/10/01). It terminates on 01-164 (6/13/01). The mm148 sequence, successfully uplinked on 01-163 (6/12/01), begins executing on 01-165 (6/14/01).
Other - Nine more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed 126 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status.
Uplinks:
There have been 18 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequences mz107 & mz108. There have been 5,437 command files radiated to the spacecraft since launch.
Upcoming Events:
DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).
Launch / Days since Launch = Nov. 7, 1996 / 1673 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 797 days
Total Mapping Orbits = 10,043
Total Orbits = 11,726
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm144 sequence executed successfully from 01-151 (5/31/01) through 01-153 (6/02/01). The mm145 sequence has performed well since it started on 01-154 (6/03/01). It terminates on 01-157 (6/06/01). The mm146 sequence, successfully uplinked on 01-156 (6/05/01), begins executing on 01-158 (6/07/01).
Other - Ten more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 117 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status.
The Sun Monitor Ephemeris fault protection is disabled to prevent another C-Mode entry due to sun-sensor shadowing by the HGA. Sun-sensor shadowing is the most likely cause of the 5/2/01 entry into C-Mode. The shadowing was caused by a combination of planetary geometry and beta-supplement HGA positioning. The 35 degree Solar Panel offpoint caused the SAM sun-sensor instead of the SAP sun-sensor to be selected for sensing sun position. Flight software could not accurately compute sun position when the SAM sun-sensor became shadowed by the HGA. Other fault protection routines continue to protect MGS from losing its attitude knowledge.
Uplinks:
There have been 13 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz104, mz105, & mz106. There have been 5,419 command files radiated to the spacecraft since launch.
Upcoming Events:
DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-179 (6/28/01). MOLA Polar Scans are scheduled for 01-193 (7/12/01) and 01-194 (7/13/01).
Launch / Days since Launch = Nov. 7, 1996 / 1666 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 790 days
Total Mapping Orbits = 9,957
Total Orbits = 11,640
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm142 sequence executed successfully from 01-144 (5/24/01) through 01-146 (5/26/01). The mm143 sequence has performed well since it started on 01-147 (5/27/01). It terminates on 01-150 (5/30/01). The mm144 sequence, successfully uplinked on 01-149 (5/29/01), begins executing on 01-151 (5/31/01).
Other - Nine more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 107 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status.
The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.
Uplinks:
There have been 17 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequence mz103.
Three solar array position management scripts were updated to offset the commanded solar array positions by 35 degrees instead of the previous offset of 25 degrees. The update should extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays
There have been 5,406 command files radiated to the spacecraft since launch.
Upcoming Events:
DOY 01-172 (6/21/01) marks the end of the beta-supplement phase and the beginning of the nominal mapping phase of the mission. Planetary and orbital geometry will allow the HGA to auto-track the Earth without impacting the HGA boom. Nominal mapping sequences will not be as command intensive as the beta-supplement sequences. Therefore, 28-day background sequences will be the norm instead of the 3 and 4 day beta-supplement sequences.
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford
University between 01-177 (6/26/01) and 01-180 (6/29/01).
Launch / Days since Launch = Nov. 7, 1996 / 1659 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 783 days
Total Mapping Orbits = 9,871
Total Orbits = 11,554
Recent Events:
Background Sequences - The spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm140 sequence executed successfully from 01-137 (5/17/01) through 01-139 (5/19/01). The mm139 sequence has performed well since it started on 01-140 (5/20/01). It terminates on 01-143 (5/23/01). The mm142 sequence, successfully uplinked on 01-142 (5/22/01), begins executing on 01-144 (5/24/01).
Other - Eleven more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 98 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status. All science instruments have been powered-on. The TES was powered-up on 01-138 (5/18/01).
The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.
Uplinks:
There have been 15 uplinks to the spacecraft during the past week, including the TES power-on command file, instrument command loads, the background sequences cited above, and ROTO mini-sequences mz100b, mz101, and mz102. There have been 5,389 command files radiated to the spacecraft since launch.
Upcoming Events:
Within the next week, we will update the three solar array position management scripts to offset the commanded solar array positions by 35 degrees instead of the present offset of 25 degrees. This update is needed to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-180 (6/29/01).
Wednesday, May 16, 2001 (DOY 129/19:00:00 to DOY 136/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1652 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 776 days
Total Mapping Orbits = 9,786
Total Orbits = 11,469
Recent Events:
Background Sequences - Except for the TES being off, the spacecraft is operating nominally in performing the beta-supplement daily recording and transmission of science data. The mm138 sequence executed successfully from 01-130 (5/10/01) through 01-132 (5/12/01). The mm139 sequence has performed well since it started on 01-133 (5/13/01). It terminates on 01-136 (5/16/01). The mm140 sequence, successfully uplinked on 01-135 (5/15/01), begins executing on 01-137 (5/17/01).
Other - Twelve Radio Science Occultation Egress Scans contained in the mz097 mini-sequence were successfully performed on 01-133 (5/13/01) and 01-134 (5/14/01). An MGS Mars Relay On-orbit UHF Test, initiated by the Mars Exploration Rover project, was conducted successfully with Stanford University on 01-135 (5/15/01) and 01-136 (5/16/01). Three more Roll Only Targeted Observations (ROTOs) were performed since the last report. MGS has completed a total of 87 ROTOs to date.
Spacecraft Health:
All subsystems report good health and status. All science instruments have been powered-on except the TES. During C-Mode recovery, the TES was powered-on, then off when it did not respond correctly to the NIPC commands prepared by the TES Team. The TES team determined the problem to be with the NIPC file itself and not the with the TES instrument. The TES will be powered-up on 01-138 (5/18/01).
The Sun Monitor Ephemeris fault protection continues to be disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.
Uplinks:
There have been 22 uplinks to the spacecraft during the past week, including three C-Mode recovery clean-up commands, new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, the mz097 Radio Science mini-sequence, and ROTO mini-sequences mz099 and mz100. There have been 5,374 command files radiated to the spacecraft since launch.
Upcoming Events:
The Thermal Emission Spectrometer will be powered-up on 01-138 (5/18/01). Within the next few weeks, we will update the three solar array position management scripts to offset the commanded solar array positions by 35 degrees instead of the present offset of 25 degrees. This update is needed to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.
Another MGS Mars Relay On-orbit UHF Test will be conducted with Stanford University between 01-177 (6/26/01) and 01-180 (6/29/01).
Launch / Days since Launch = Nov. 7, 1996 / 1645 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 769 days
Total Mapping Orbits = 9,701
Total Orbits = 11,384
Recent Events:
Background Sequences - There have been no background sequences operating since MGS entered C-Mode a week ago on 01-122 (5/02/01). Last week, the mm135 sequence terminated approximately fourteen hours earlier than expected due to C-Mode entry. The mm136 sequence, though uplinked, was prevented from starting on 01-123 (5/3/01) by C-Mode. The mm137 sequence was never uplinked. Recovery efforts have gone well the past two days and we expect to start normal background sequencing with mm138. It will start today, 01-129 (5/9/01), at 23:57:00 UTC Spacecraft Event Time. mm139 is scheduled for uplink on 01-131 (5/11/01). It will commence on 01-133 (5/13/01).
Other - No ROTOs or other special science scans were conducted this week.
The mz095 mini-sequence was used to return MGS to its normal NADIR pointing
attitude. It also triggered an on-board command script to control movement
of the HGA and operate the downlink transmitter during the transition from
C-Mode to nominal mapping. The mz096 mini-sequence was prepared in the optimistic
hope that we might recover in time to conduct a ROTO. It was never uplinked
due to the intense effort required to prepare and uplink the C-Mode recovery
command files. The mz098 mini-sequence was uplinked today to terminate the
HGA command script shortly before the mm138 background sequence goes active.
Spacecraft Health:
All subsystems report good health and status. All science instruments have been powered-on except the TES. The TES was powered-on, then off when it did not respond correctly to the NIPC commands prepared by the TES Team. The TES team suspects that the problem may be with the NIPC file itself and not the with the TES instrument.
The Sun Monitor Ephemeris fault detection and response have been disabled to prevent another C-Mode entry while the Spacecraft Team investigates the root cause of the failure. Other fault protection routines will continue to protect MGS from losing its attitude knowledge.
Uplinks:
There have been 66 C-Mode recovery uplinks to the spacecraft during the past week. There have been 5,352 command files radiated to the spacecraft since launch.
Upcoming Events:
The Radio Science Occultation Egress Scans contained in the mz097 mini-sequence should take place as scheduled on 01-133 (5/13/01) and 01-134 (5/14/01). An MGS Mars Relay On-orbit UHF Test, initiated by the Mars Exploration Rover project, will be conducted with Stanford University on 01-135 (5/15/01) and 01-136 (5/16/01).
Launch / Days since Launch = Nov. 7, 1996 / 1638 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 762 days
Total Mapping Orbits = 9,615
Total Orbits = 11,298
Recent Events:
Background Sequences -- The spacecraft is now in Contingency Mode (C-Mode), so background sequence processing has terminated until the Spacecraft Team intervenes. The mm134 sequence executed successfully from 01-116 (4/26/01) through 01-118 (4/28/01). The mm135 sequence performed well from the time it started on 01-119 (4/29/01) until it terminated on 01-122 (5/02/01) at 10:10:55 Spacecraft Event Time (SCET) with a C-Mode entry. The mm136 sequence, successfully uplinked on 01-121 (5/01/01), was to begin executing on 01-123 (5/03/01), but will not due to the C-Mode entry.
Other - MGS transmitted high frequency spacecraft body rate data to Earth
on 01-115 (4/25/01). The data will provide insight into the health of the
-Y solar array hinge and the effects of solar array motion on TES data.
Four of five MOC Defocus Calibration Scans were performed by the mm134 and
mm135 sequences before C-Mode was entered. The fifth scan may be made-up
at some future date. All four ROTOs contained in the mz093 mini-sequence
were performed. The mz094 mini-sequence, containing five ROTOs, will not
be uplinked due to C-Mode recovery. MGS has performed 84 Roll Only Targeted
Observations to date.
Spacecraft Health:
All subsystems report good health and safe status consistent with C-Mode entry. Downlink telemetry is consistent with the following C-Mode state: Spacecraft coning about the sun with the solar arrays automatically tracking the sun and generating adequate power; HGA "frozen" in the position it was in when the spacecraft entered C-Mode; 7.8125 bps uplink and 10 bps downlink communications provided through the LGA; science instruments powered off.
MGS project engineers have initiated the C-Mode Recovery Plan.
We know that the Sun Monitor Ephemeris fault response sent MGS into C-Mode but we do not know why. The spacecraft continually compares the sun position calculated from on-board sun sensors to the expected sun position provided by the Spacecraft Team. When the two positions diverge greater that five degrees for greater than two seconds, the Sun Monitor Ephemeris fault response initiates C-Mode.
Uplinks:
There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequence mz093.
There have been 5,286 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm137 background sequence will not be uplinked on 01-124 (5/04/01) because we are recovering from C-mode. If the recovery effort goes well, background sequence processing will start with mm138. Radio Science Occultation Egress Scans are scheduled for 01-133 (5/13/01) and 01-134 (5/14/01). An MGS Mars Relay On-orbit UHF Test, initiated by the Mars Exploration Rover project, will be conducted with Stanford University on 01-135 (5/15/01) and 01-136 (5/16/01).
Launch / Days since Launch = Nov. 7, 1996 / 1631 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 755 days
Total Mapping Orbits = 9,530
Total Orbits = 11,213
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm132 sequence executed successfully from 01-109 (4/19/01) through 01-111 (4/21/01). The mm133 sequence has performed well since it started on 01-112 (4/22/01). It terminates on 01-115 (4/25/01). The mm134 sequence, successfully uplinked on 01-114 (4/24/01), begins executing on 01-116 (4/26/01).
Other - MGS transmitted high frequency spacecraft body rate data to Earth
on 01-115 (4/25/01). The data will provide insight into the health of the
-Y solar array hinge and the effects of solar array motion on TES data.
MGS has performed 75 Roll Only Targeted Observations to date.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 12 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz091 through mz092.
The last two of three solar array position management scripts were modified to offset the commanded solar array positions by 25 degrees. Our goal is to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays.
There have been 5,270 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm135 background sequence will be uplinked on 01-117 (4/27/01). MOC Defocus Calibration Scans will be performed by the mm134 and mm135 sequences between 01-116 (4/26/01) and 01-123 (5/02/01). Radio Science Occultation Egress Scans are scheduled for 01-132 (5/12/01) and 01-133 (5/13/01). ROTO mini-sequences mz092 and mz093 will execute this next week.
This report covers two weeks.
Launch / Days since Launch = Nov. 7, 1996 / 1624 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 748 days
Total Mapping Orbits = 9,444
Total Orbits = 11,127
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm128, mm129, and mm130 sequences executed successfully from 01-095 (4/05/01) through 01-104 (4/14/01). The mm131 sequence has performed well since it started on 01-105 (4/15/01). It terminates on 01-108 (4/18/01). The mm132 sequence, successfully uplinked on 01-107 (4/17/01), begins executing on 01-109 (4/19/01).
Other - MGS successfully performed twelve Radio Science Occultation Egress
Scans on 01-095 (4/5/01) and 01-096 (4/6/01). They were contained in the
mz085 mini-sequence. MGS has performed 65 Roll Only Targeted Observations
to date.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 30 uplinks to the spacecraft during the past two weeks, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, a thruster accumulator reset command, and ROTO mini-sequences mz086 through mz090.
Commands were uplinked to modify the Reaction Wheel Assembly fault protection software and associated scripts. The modified response will allow a quicker recovery should another reaction wheel fail.
The first of three solar array position management scripts was modified to offset the commanded solar array positions by 25 degrees. Our goal is to extend the life of the Partial Shunt Assemblies by reducing the amount of excess power generated by the solar arrays. We will update the other two scripts after verifying the expected spacecraft performance under the first script.
There have been 5,258 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm133 background sequence will be uplinked on 01-110 (4/20/01). On 01-115 (4/25/01) of that sequence, MGS will transmit high frequency spacecraft body rate data to Earth. The data will provide insight into the health of the -Y solar array hinge and the effects of solar array motion on TES data. MOC Defocus Calibration Scans will be performed by the mm134 and mm135 sequences between 01-116 (4/26/01) and 01-123 (5/02/01). Radio Science Occultation Egress Scans are scheduled for 01-132 (5/12/01) and 01-133 (5/13/01).
ROTO mini-sequences mz090 and mz091 will execute this next week.
Launch / Days since Launch = Nov. 7, 1996 / 1610 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 734 days
Total Mapping Orbits = 9,272
Total Orbits = 10,955
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm126 sequence executed successfully from 01-088 (3/29/01) through 01-090 (3/31/01). The mm127 sequence has performed well since it started on 01-091 (4/01/01). It terminates on 01-094 (4/04/01). The mm128 sequence, successfully uplinked on 01-093 (4/03/01), begins executing on 01-095 (4/05/01).
Other - MGS performed 6 Roll Only Targeted Observations since the last
status report, bringing the total number of ROTOs to 46.
Spacecraft Health:
All subsystems report nominal health.
Uplinks: There have been 15 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, ROTO mini-sequence mz084, and Radio Science Occultation Egress Scan mini-sequence mz085. There have been 5,228 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm129 background sequence will be uplinked on 01-096 (4/06/01). ROTO mini-sequences mz086 and mz087 will be uplinked and executed this next week. Radio Science Occultation Egress Scans, contained in the mz085 mini-sequence, will take place on 01-095 (4/5/01) and 01-096 (4/6/01).
Wednesday, March 28, 2001 (DOY 080/19:00:00 to DOY 087/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1603 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 727 days
Total Mapping Orbits = 9,162
Total Orbits = 10,845
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm124 sequence executed successfully from 01-081 (3/22/01) through 01-083 (3/24/01). The mm125 sequence has performed well since it started on 01-084 (3/25/01). It terminates on 01-087 (3/28/01). The mm126 sequence, successfully uplinked on 01-086 (3/27/01), begins executing on 01-088 (3/29/01).
Other - On 01-082 (3/23/01), the mz081 Relay-22 mini-sequence commanded MGS to a more fuel-efficient attitude by inducing a +22 degree Pitch offset. The spacecraft maintained this attitude for approximately eight hours. The data collected helped characterize the thermal, momentum buildup, fuel usage, and Starex processing profiles of the spacecraft in the new attitude.
During the Relay-22 Demo, Thermal subsystem performance was nominal. The predicted temperature response agreed well with the observed data. Temperature changes were generally small with the single exception of the MOC secondary mirror, which showed a 5°C temperature increase as predicted. This increase is not a concern. There are no thermal issues for the expected final pitch angle of somewhat less than 22 degrees.
Attitude Control also looked nominal but requires more investigation since the MOC team reported Roll offpoints large enough to be noticed by their instrument. The spin momentum buildup rate was -0.5 Nms/hr, which would result in an unload event every 18 hours vs. the present 7.5 hours. Adjusting current fuel use to the new rate of spin momentum buildup, we estimate the daily fuel use for the new configuration to be approximately 15 g/day (11 g/day spin, 4 g/day yaw). This represents approximately half the fuel consumption of the nominal attitude profile. We anticipate a Pitch offset near 16 degrees to be near optimum. As expected, there was no noticeable change in the Yaw momentum buildup rate. Starex performed nominally, converging in 11 stars. No major changes in gyro biases (versus nominal) were observed.
We were unable to collect high frequency body rate data because of a subtle error in the way the Solid State Recorders were commanded. We expect to collect this data in the near future in order to diagnose the health of the -Y solar array hinge. The data will also help us determine what effect solar array motion has on TES instrument data.
The Power subsystem performed nominally during the Relay-22 Demonstration.
Three new Solar Array Autonomous Eclipse Management scripts were loaded into memory this week. They will go active on 01-088 (3/29/01), returning Solar Array management from a 4-motion strategy to a 3-motion strategy. This may extend the life of the solar array gimbals and may reduce solar array noise effects upon the TES data.
MGS performed 4 Roll Only Targeted Observations since the last status
report, bringing the total number of ROTOs to 40.
Spacecraft Health:
All subsystems report nominal health.
Uplinks: There have been 13 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, ROTO mini-sequences mz082 and mz083, and three modified Solar Array Autonomous Eclipse Management scripts. There have been 5,213 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm127 background sequence will be uplinked on 01-089 (3/30/01). ROTO mini-sequences mz084 and mz085 will be uplinked and executed this next week. Radio Science Occultation Egress Scans, contained in the mz085 mini-sequence, will take place on 01-095 (4/5/01) and 01-096 (4/6/01).
Launch / Days since Launch = Nov. 7, 1996 / 1596 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 720 days
Total Mapping Orbits = 9,102
Total Orbits = 10,785
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm122 sequence executed successfully from 01-074 (3/15/01) through 01-076 (3/17/01). The mm123 sequence has performed well since it started on 01-077 (3/18/01). It terminates on 01-080 (3/21/01). The mm124 sequence, successfully uplinked on 01-079 (3/20/01), begins executing on 01-081 (3/22/01).
Other - MGS performed 10 Roll Only Targeted Observations since the last
status report, bringing the total number of ROTOs to 36.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 10 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, the ROTO mini-sequence mz080, and the Relay-22 Demo mini-sequence mz081. There have been 5,200 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm125 background sequence will be uplinked on 01-082 (3/23/01). ROTO mini-sequences mz082 and mz083 will be uplinked and executed this next week. On 01-082 (3/23/01), the mz081 mini-sequence will command MGS to a more fuel-efficient attitude for approximately four hours. The data collected during this demonstration will allow us to characterize the thermal, momentum buildup, fuel usage, and Starex processing profiles of the spacecraft in the new attitude. We will also gather high frequency body rate data to diagnose the health of the -Y solar array hinge. This knowledge will help us plan for future mission activities.
Wednesday, March 14, 2001 (DOY 066/19:00:00 to DOY 073/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1589 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 713 days
Total Mapping Orbits = 9,016
Total Orbits = 10,699
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm120 sequence executed successfully from 01-067 (3/08/01) through 01-069 (3/10/01). The mm121 sequence has performed well since it started on 01-070 (3/11/01). It terminates on 01-073 (3/14/01). The mm122 sequence, successfully uplinked on 01-072 (3/13/01), begins executing on 01-074 (3/15/01).
Other - MGS performed 9 Roll Only Targeted Observations since the last
status report, bringing the total number of ROTOs to 26.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 20 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and ROTO mini-sequences mz077 and mz078. There have been 5,190 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm123 background sequence will be uplinked on 01-075 (3/16/01). ROTO mini-sequences mz079 and mz080 will be uplinked and executed this next week. On 01-082 (3/23/01), the mz081 mini-sequence will command MGS to a more fuel-efficient attitude for approximately four hours. The data collected during this demonstration will allow us to characterize the thermal, momentum buildup, fuel usage, and Starex processing profiles of the spacecraft in the new attitude. We will also gather high frequency body rate data to diagnose the health of the -Y solar array hinge. This knowledge will help us plan for future mission activities.
Launch / Days since Launch = Nov. 7, 1996 / 1582 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 706 days
Total Mapping Orbits = 8,930
Total Orbits = 10,613
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm118 sequence executed successfully from 01-060 (3/01/01) through 01-062 (3/03/01). The mm119 sequence has performed well since it started on 01-063 (3/04/01). It terminates on 01-066 (3/07/01). The mm120 sequence, successfully uplinked on 01-065 (3/06/01), begins executing on 01-067 (3/08/01).
Other - MGS performed 11 Roll Only Targeted Observations since the last status report, bringing the total number of ROTOs to 17.
A flight software patch to the Safe Mode code was uplinked on 01-060 (3/01/01). The purpose of this patch is to prevent the HGA from entering the HGA exclusion zone during a Safe Mode entry. The patch reduces HGA risk and allows increased SSR playback time or increased real-time data transmission during every communications orbit.
A parameter update was uplinked on 01-064 (3/05/01) to ensure entry into
the Safe Mode response if another RWA failure occurs.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 26 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, the Safe Mode patch and parameter update, and ROTO mini-sequences mz075 and mz076. There have been 5,170 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm121 background sequence will be uplinked on 01-068 (3/09/01). ROTO mini-sequences mz077 and mz078 will be uplinked and executed this next week.
Launch / Days since Launch = Nov. 7, 1996 / 1575 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 699 days
Total Mapping Orbits = 8,836
Total Orbits = 10,519
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm116 sequence executed successfully from 01-053 (2/22/00) through 01-055 (2/24/01). The mm117 sequence has performed well since it started on 01-056 (2/25/01). It terminates on 01-059 (2/28/01). The mm118 sequence, successfully uplinked on 01-058 (2/27/01), begins executing on 01-060 (3/01/01).
Other - MGS performed five Roll Only Targeted Observations since the
last status report, bringing the total number of ROTOs to six.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 9 uplinks to the spacecraft during the past week, including instrument command loads, the background sequences cited above, and ROTO mini-sequences mz073 and mz074. There have been 5,144 command files radiated to the spacecraft since launch.
Upcoming Events:
A flight software patch to the Safe Mode code will be uplinked on 01-060 (3/01/01). The purpose of this patch is to prevent the HGA from entering the HGA exclusion zone during a Safe Mode entry. Presently, when the S/C enters Safe Mode, the HGA automatically slews directly to a predetermined target position. Unfortunately, this type of slew poses a risk in some cases due to the HGA gimbal obstruction. It is possible that the HGA could drive through the HGA exclusion zone on its way to the target position. The project has mitigated this risk to date by building background sequences that avoid commanding the HGA into potentially hazardous positions. The unfortunate trade-off has been reduced communications time each orbit. The HGA Safe Mode software patch causes the HGA to "freeze" its position upon Safe Mode entry. Consequently, the project regains communications time every orbit by moving the risk mitigation from nominal sequencing to the Safe Mode fault response.
The mm119 background sequence will be uplinked on 01-061 (3/02/01). ROTO mini-sequences mz075 and mz076 will be uplinked and executed this next week.
Launch / Days since Launch = Nov. 7, 1996 / 1568 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 692 days
Total Mapping Orbits = 8,759
Total Orbits = 10,442
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm114 sequence executed successfully from 01-046 (2/15/00) through 01-048 (2/17/01). The mm115 sequence has performed well since it started on 01-049 (2/18/01). It terminates on 01-052 (2/21/01). The mm116 sequence, successfully uplinked on 01-051 (2/20/01), begins executing on 01-053 (2/22/01).
Other - MGS performed flawlessly during the Roll Only Targeted Observation demonstration executed on orbit #8690 of 01-047 (2/16/00). Post-test analyses of the engineering data verified nominal performance by all subsystems.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 6 uplinks to the spacecraft during the past week, including instrument command loads and the background sequences cited above. There have been 5,135 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm117 background sequence will be uplinked on 01-054 (2/23/01). Because the ROTO demonstration was successful, standard procedure will be to uplink two ROTO mini-sequences each week. The ROTO mini-sequences for this next week are mz073 and mz074.
Launch / Days since Launch = Nov. 7, 1996 / 1554 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 678 days
Total Mapping Orbits = 8,575
Total Orbits = 10,258
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm110 sequence executed successfully from 01-032 (2/1/00) through 01-034 (2/3/01). The mm111 sequence has performed well since it started on 01-035 (2/4/01). It terminates on 01-038 (2/7/01). The mm112 sequence, successfully uplinked on 01-037 (2/6/01), begins executing on 01-039 (2/08/01).
Other - Another successful DDOR experiment was performed on 01-034 (2/3/01) as part of the mm110 background sequence.
Spacecraft Health:
All subsystems report nominal health. Investigation into the root cause of the X-axis Reaction Wheel failure continues. Although we are confident that a short circuit within the RWA-X electronics caused the failure, isolating the exact piece-part that failed seems unlikely. Work continues in identifying operational impacts associated with using RWA-S for attitude control. We are also investigating methods of protecting the spacecraft against a second RWA failure.
Uplinks:
There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. We also increased the Momentum Unload Give Up Timer to 120 minutes so that manually induced momentum unloads do not terminate prematurely due to worst-case phasing errors. (See the 1/24/01 MGS Status Report) Finally, we reset the Audit Queue Counter to a value consistent with the Audit Queue activity that occurred since the counter reached its maximum value of 255. This particular counter does not rollover automatically and must be reset with a ground command when it reaches its maximum value. There have been 5,113 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm113 background sequence will be uplinked on 01-040 (2/09/01). Development of the mz072 Roll Only Targeted Observation (ROTO) Demonstration mini-sequence will commence on 01-043 (2/12/01).
Launch / Days since Launch = Nov. 7, 1996 / 1540 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 664 days
Total Mapping Orbits = 8,416
Total Orbits = 10,099
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm106 sequence executed successfully from 01-018 (1/18/00) through 01-020 (1/20/01). The mm107 sequence has performed well since it started on 01-021 (1/21/01). It terminates on 01-024 (1/24/01). The mm108 sequence, successfully uplinked on 01-023 (1/23/01), begins executing on 01-025 (1/25/01).
Other - Two unrelated spacecraft anomalies occurred on 01-018 (1/18/91).
The first anomaly occurred within the first two hours of 01-018 (1/18/91). A Yaw Axis momentum unload terminated prematurely, failing to completely unload Z-Axis momentum to 1.0 Nms. Instead, the momentum unload terminated at 2.5 Nms. This required flight software to immediately command another Yaw Axis momentum unload to complete the task of reaching 1.0 Nms. Subsequent analysis revealed that the unload was prematurely terminated by the "give up" timer used to prevent unloads from persisting beyond the time span allowed. The Yaw unload in question was induced by the mz070 MOLA Polar Scan mini-sequence. Commands within the mini-sequence lowered the unload threshold to 2.0 Nms in order to dump momentum before the MOLA Polar Scans began. This routine procedure was required because MOLA Polar Scans do not allow proper Yaw momentum unloading. Unfortunately, the timing of the induced unload was out-of-phase with the momentum profile for that particular orbit. Flight software waited appropriately until the unload could be accomplished in-phase with the momentum profile. However, the delay stretched the execution of the unload beyond the established "give up" boundary and the unload terminated early. Flight software responded appropriately throughout this scenario, eventually reducing the Z-Axis momentum to 1.0 Nms without ground intervention. The MOLA Polar scans for the subsequent three orbits executed nominally. Corrective action to increase the "give-up" timer parameter is in work to ensure that future momentum unloads do not terminate prematurely due to worst-case phasing errors.
The second anomaly involved a hardware failure on 01-018 (1/18/01). At approximately 15:35:43 Spacecraft Event Time (SCET) Universal Time Coordinated (UTC), the X-axis Reaction Wheel Assembly (RWA-X) failed. Redundancy Management (REDMAN) code within flight software reacted appropriately by switching X-axis attitude control to the redundant "Skew" Reaction Wheel Assembly (RWA-S). Stored-sequence command processing proceeded nominally, allowing MGS to continue mapping without interruption. A command was uplinked on 01-019 (1/19/01) to terminate the mz070 mini-sequence, thereby ensuring the MOLA Polar Scans would not occur until the anomaly was understood. On 01-020 (1/20/91), a command was uplinked to keep RWA-S reaction wheel speeds within comfotable limits by reducing the nominal Yaw Axis momentum unload threshold from 10 Nms to 6 Nms. The mz071C mini-sequence was uplinked and executed on 01-024 (1/24/91) to determine the future availability of RWA-X. RWA-X did not respond during the 20-second test, verifying that it had failed. The spacecraft team is continuing its probe into the probable root cause(s) of the failure. The leading theory is that a component failed in the RWA-X electronics. Our goal is to determine the most probable root cause(s) of the failure so that we can adequately maintain spacecraft health and capability to achieve extended mission objectives. Meanwhile, the MGS spacecraft is operating as designed on the redundant reaction wheel.
One Delta Differential One-Way Range (DDOR) experiment was conducted on 01-024 (1/24/01).
Spacecraft Health:
RWA-X has failed, forcing the Attitude and Articulation Control Subsystem (AACS) to operate on the redundant "skew" reaction wheel for attitude control about the X-axis. The Electrical Power Subsystem (EPS) experienced a fault that probably originated in the RWA-X electronics. The fault has cleared and the EPS is operating normally. The TWTA-2 filament of the Telecommunications subsystem switched OFF in response to the EPS fault, as designed. It is back on line and operating nominally. The Payload Data Subsystem (PDS) experienced a "warm" Power On Reset (POR) and the payload bus current momentarily dropped by 0.2 amps. The PDS RAM remained intact, allowing the PDS to recover within two telemetry frames. All other subsystems report nominal health.
Uplinks:
There have been 18 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, the background sequences, anomaly related commands, and the mz071 mini-sequence. There have been 5,091 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm109 background sequence will be uplinked on 01-026 (1/26/01). The Roll Only Targeted Observation (ROTO) demonstration scheduled for this weekend has been delayed pending results from the anomaly investigation. Another DDOR experiment is scheduled for 01-027 (1/27/01). It is contained in the mm108 sequence. 01-031 (1/31/01) will mark the end of the MGS primary mission and 01-032 (2/1/01) will mark our entry into the extended mission phase.
Launch / Days since Launch = Nov. 7, 1996 / 1533 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 657 days
Total Mapping Orbits = 8,331
Total Orbits = 10,014
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm104 sequence executed successfully from 01-011 (1/11/00) through 01-013 (1/13/01). The mm105 sequence has performed well since it started on 01-014 (1/14/01). It terminates on 01-017 (1/17/01). The mm106 sequence, successfully uplinked on 01-016 (1/16/01), begins executing on 01-018 (1/18/01).
Other - MGS successfully completed twelve Radio Science Occultation Egress Scans from 01-010 (1/10/01) to 01-011 (01/11/01). One Delta Differential One-Way Range (DDOR) experiment was conducted on 01-013 (1/13/01). Data from this and other DDOR experiments are being analyzed and should assist the Mars Odyssey Program in calibrating the interplanetary navigation system.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 8 uplinks to the spacecraft during the last week, including instrument command loads, the background sequences cited above, and the mz070 mini-sequence. There have been 5,073 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm107 background sequence will be uplinked on 01-019 (1/19/01). MOLA Polar Scans, contained in the mz070 mini-sequence, are scheduled for 01-018 (1/18/01) through 01-022 (1/22/01). On 01-025 (1/25/01), a Roll Only Targeted Observation (ROTO) demonstration will be conducted on the spacecraft. It will verify our readiness to conduct these observations during the extended mission. Two more DDOR experiments are scheduled for 01-024 (1/24/01) and 01-027 (1/27/01). 01-031 (1/31/01) will mark the end of the MGS primary mission and 01-032 (2/1/01) will mark our entry into the extended mission.
Launch / Days since Launch = Nov. 7, 1996 / 1526 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 650 days
Total Mapping Orbits = 8,245
Total Orbits = 9,848
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm102 sequence executed successfully from 01-004 (1/4/00) through 01-006 (1/6/01). The mm103 sequence has performed well since it started on 01-007 (1/7/01). It terminates on 01-010 (1/10/01). The mm104 sequence, successfully uplinked on 01-009 (1/9/01), begins executing on 01-011 (1/11/01).
Other -- Two Delta Differential One-Way Range (DDOR) experiments were conducted on 01-009 (1/9/01). Data from these DDOR experiments are being analyzed and should assist the Mars Odyssey Program in calibrating the interplanetary navigation system.
Spacecraft Health:
All subsystems report nominal health.
Uplinks: There have been 16 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, the background sequences cited above, and the mz068 and mz069 mini-sequences. There have been 5,065 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm105 background sequence will be uplinked on 01-012 (1/12/01). Radio
Science Occultation Egress Scans, scheduled for 01-010 (1/10/01) through
01-011 (01/11/01), will be commanded by the,mz068, & mz069 mini-sequences.
Another DDOR experiment will be conducted on 01-013 (1/13/01). MOLA Polar
Scans are scheduled for 01-018 (1/18/01) through 01-022 (1/22/01). On 01-025
(1/25/01), a Roll Only Targeted Observation (ROTO) demonstration will be
conducted on the spacecraft. It will verify our readiness to conduct these
observations during the extended mission. Two more DDOR experiments are
scheduled for 01-024 (1/24/01) and 01-027 (1/27/01). 01-031 (1/31/01) will
mark the end of the MGS primary mission and 01-032 (2/1/01) will mark our
entry into the extended mission.
Launch / Days since Launch = Nov. 7, 1996 / 1505 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 629 days
Total Mapping Orbits = 7,988
Total Orbits = 9,591
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm096 sequence executed successfully from 00-349 (12/14/00) through 00-351 (12/16/00). The mm097 sequence has performed well since it started on 00-352 (12/17/00). It terminates on 00-355 (12/20/00). The mm098 sequence, successfully uplinked on 00-354 (12/19/00), begins executing on 00-356 (12/21/00).
Other -- Science Campaign F, which started on 00-345 (12/10/00), finishes tomorrow 00-356 (12/21/00). MGS received 24 hour/day coverage during the campaign, greatly increasing the amount of high resolution real-time science data that it transmitted to Earth. The first of two back-to-back Radio Science Occultation Egress Scan experiments was successfully completed yesterday 00-354 (12/19/00). The second experiment started today and terminates tomorrow 00-356 (12/21/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 19 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. There have been 5,026 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm099, mm100, mm101, and mm102 background sequences will be uplinked
on 00-357 (12/22/00), 00-361 (12/26/00), 00-364 (12/29/00), and 01-002 (01/02/01)
respectively. Two Delta Differential One-Way Range (DDOR) experiments will
be conducted on 01-009 (1/9/01). Data from these DDOR experiments will assist
the Mars Odyssey Program in calibrating the interplanetary navigation system.
Radio Science Occultation Egress Scans, scheduled for 01-010 (1/10/01) through
01-011 (01/11/01), will be commanded by the,mz068, & mz069 mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1498 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 622 days
Total Mapping Orbits = 7,902
Total Orbits = 9,505
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm094 sequence executed successfully from 00-342 (12/7/00) through 00-344 (12/9/00). The mm095 sequence has performed well since it started on 00-345 (12/10/00). It terminates on 00-348 (12/13/00). The mm096 sequence, successfully uplinked on 00-347 (12/12/00), begins executing on 00-349 (12/14/00).
Other - No special science scans were conducted this week. Science Campaign F started on 00-345 (12/10/00) and lasts until 00-356 (12/21/00). MGS is receiving 24 hour/day coverage during the campaign, greatly increasing the amount of high resolution real-time science data that it transmits to Earth.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 7 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 5,007 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm097 background sequence will be uplinked on 00-350 (12/15/00).
Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00)
through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067
mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1491 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 615 days
Total Mapping Orbits = 7,817
Total Orbits = 9,420
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm092 sequence executed successfully from 00-335 (11/30/00) through 00-337 (12/2/00). The mm093 sequence has performed well since it started on 00-338 (11/3/00). It terminates on 00-341 (11/6/00). The mm094 sequence, successfully uplinked on 00-340 (12/5/00), begins executing on 00-342 (12/7/00).
Other - No special science scans were conducted this week.
Spacecraft Health:
All subsystems report nominal health.
Uplinks: There have been 8 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 5,000 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm095 background sequence will be uplinked on 00-343 (12/8/00). Science
Campaign F commences on 00-345 (12/10/00) and lasts until 00-356 (12/21/00).
Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00)
through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067
mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1484 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 608 days
Total Mapping Orbits = 7,731
Total Orbits = 9,334
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm090 sequence executed successfully from 00-328 (11/23/00) through 00-330 (11/25/00). The mm091 sequence has performed well since it started on 00-331 (11/26/00). It terminates on 00-334 (11/29/00). The mm092 sequence, successfully uplinked on 00-333 (11/28/00), begins executing on 00-335 (11/30/00).
The background sequences now command SSR record and playback rates of 8 ksps and 42 ksps respectively. We were able to double the previous rates because of the improved telecom link margin available, as Earth and Mars get closer to each other. The change took effect on 00-331 (11/26/00).
Other - No special science scans were conducted this week.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. There have been 4,992 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm093 background sequence will be uplinked on 00-336 (12/1/00). Science
Campaign F commences on 00-345 (12/10/00) and lasts until 00-356 (12/21/00).
Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00)
through 00-356 (12/21/00), will be commanded by the mz065,mz066, & mz067
mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1477 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 601 days
Total Mapping Orbits = 7,645
Total Orbits = 9,248
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm088 sequence executed successfully from 00-321 (11/16/00) through 00-323 (11/18/00). The mm089 sequence has performed well since it started on 00-324 (11/20/00). It terminates on 00-327 (11/22/00). The mm090 sequence, successfully uplinked on 00-326 (11/21/00), begins executing on 00-328 (11/23/00).
Other - Radio Science Occultation Egress Scans, contained in the mz063 and mz064 mini-sequences, were accomplished successfully on 00-322 (11/17/00) through 00-325 (11/20/00). Twenty-four total scans were performed.
Spacecraft Health:
All subsystems report nominal health. Telecom link margin is improving as the distance between Earth and Mars decreases. This will allow us to increase the record and playback rates by a factor of two. We plan to increase the record rate to 8 ksps on 00-331 (11/26/00) and the playback rate to 42 ksps on 00-332 (11/27/00).
Uplinks:
There have been 17 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. There have been 4,979 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm091 background sequence will be uplinked on 00-329 (11/24/00). Science Campaign F commences on 00-345 (12/10/00) and lasts until 00-356 (12/21/00). Radio Science Occultation Egress Scans, scheduled for 00-353 (12/18/00) through 00-356 (12/21/00), will be commanded by the mz065 & mz066 mini-sequences.
Wednesday, November 15, 2000 (DOY 313/19:00:00 to DOY 320/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1470 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 594 days
Total Mapping Orbits = 7,559
Total Orbits = 9,162
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm086 sequence executed successfully from 00-314 (11/9/00) through 00-316 (11/11/00). The mm087 sequence has performed well since it started on 00-317 (11/13/00). It terminates on 00-320 (11/15/00). The mm088 sequence, successfully uplinked on 00-319 (11/14/00), begins executing on 00-321 (11/16/00).
Other - MOLA Polar Scans, contained in the mz062 mini-sequence, were performed successfully on 00-316 (11/11/00) through 00-319 (11/14/00). Data processing will begin as soon as the data are available on the central database.
Spacecraft Health:
All subsystems report nominal health. Telecom link margin is improving as the distance between Earth and Mars decreases. This will allow us to increase the record and playback rates by a factor of two. We plan to increase the record rate to 8 ksps on 00-331 (11/26/00) and the playback rate to 42 ksps on 00-332 (11/27/00).
Uplinks:
There have been 15 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the sequences cited above. Unfortunately, seven uplinks attempted today (00-320) were unsuccessful due to bad spacecraft frequency predictions. The affected command files will be uplinked tomorrow morning, 00-321 (11/16/00). There have been 4,947 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm089 background sequence will be uplinked on 00-322 (11/17/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz063 & mz064 mini-sequences. The mz063a command file will be retransmitted to the spacecraft tomorrow, 00-321 (11/16/00), because today's attempt failed as explained above.
Launch / Days since Launch = Nov. 7, 1996 / 1463 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 587 days
Total Mapping Orbits = 7,473
Total Orbits = 9,076
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm084 sequence executed successfully from 00-307 (11/2/00) through 00-309 (11/4/00). The mm085 sequence has performed well since it started on 00-310 (11/6/00). It terminates on 00-313 (11/8/00). The mm086 sequence, successfully uplinked on 00-312 (11/7/00), begins executing on 00-314 (11/9/00).
Other - No special science scans were conducted this week.
Spacecraft Health:
All subsystems report nominal health. The Safe Mode mission-phase-relays have been commanded to the Mapping state. Therefore, in the unlikely event that MGS enters Safe Mode, it will remain in a positive power margin state.
Uplinks:
There have been 8 uplinks to the spacecraft during the last week, including instrument command loads, the sequences cited above, and the command to change the mission-phase-relays to Mapping. There have been 4,947 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm087 background sequence will be uplinked on 00-315 (11/10/00). MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz063 & mz064 mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1449 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 573 days
Total Mapping Orbits = 7,303
Total Orbits = 8,906
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm080 sequence executed successfully from 00-293 (10/19/00) through 00-295 (10/21/00). The mm081 sequence has performed well since it started on 00-296 (10/22/00). It terminates on 00-299 (10/25/00). The mm080 sequence, successfully uplinked on 00-298 (10/24/00), begins executing on 00-300 (10/26/00).
Other - No special science scans were conducted this week.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 7 uplinks to the spacecraft during the last week, including instrument command loads and the sequences cited above. There have been 4,924 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm083 background sequence will be uplinked on 00-301 (10/27/00). The next set of specialized science observations occur in November. MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz063 mini-sequence.
Launch / Days since Launch = Nov. 7, 1996 / 1442 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 566 days
Total Mapping Orbits = 7,217
Total Orbits = 8,820
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm078 sequence executed successfully from 00-286 (10/12/00) through 00-288 (10/14/00). The mm079 sequence has performed well since it started on 00-289 (10/15/00). It terminates on 00-292 (10/18/00). The mm080 sequence, successfully uplinked on 00-291 (10/17/00), begins executing on 00-293 (10/19/00).
Other - MGS successfully completed twelve Radio Science Occultation Egress Scans on 00-287 (10/13/00) and 00-288 (10/14/00). They were part of the mz061 mini-sequence.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads and the sequences cited above. There have been 4,917 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm081 background sequence will be uplinked on 00-294 (10/20/00).
The next set of specialized science observations occur in November. MOLA
Polar Scans, contained in the mz062 mini-sequence, will be performed on
00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress
Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be
commanded by the mz062 mini-sequence.
Launch / Days since Launch = Nov. 7, 1996 / 1435 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 559 days
Total Mapping Orbits = 7,131
Total Orbits = 8,734
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm076 sequence executed successfully from 00-279 (10/5/00) through 00-281 (10/7/00). The mm077 sequence has performed well since it started on 00-282 (10/8/00). It terminates on 00-285 (10/11/00). The mm078 sequence, successfully uplinked on 00-285 (10/11/00), begins executing on 00-286 (10/12/00).
Other - MGS completed fifteen MOLA Polar Scans over five days from 00-281 (10/7/00) through 00-285 (10/11/00). They were part of the mz059 mini-sequence.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads and the sequences cited above. There have been 4,904 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm079 background sequence will be uplinked on 00-287 (10/13/00). The next set of specialized science observations occur in November. MOLA Polar Scans, contained in the mz062 mini-sequence, will be performed on 00-316 (11/11/00) through 00-319 (11/14/00). Radio Science Occultation Egress Scans, scheduled for 00-322 (11/17/00) through 00-325 (11/20/00), will be commanded by the mz062 mini-sequence.
Wednesday, October 4, 2000 (DOY 271/19:00:00 to DOY 278/19:00:00 UTC)
Launch / Days since Launch = Nov. 7, 1996 / 1428 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 552 days
Total Mapping Orbits = 7,045
Total Orbits = 8,648
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm074 sequence executed successfully from 00-272 (9/28/00) through 00-274 (9/30/00). The mm075 sequence has performed well since it started on 00-275 (10/1/00). It terminates on 00-278 (10/4/00). The mm076 sequence, successfully uplinked on 00-277 (10/3/00), begins executing on 00-279 (10/5/00).
Other - This week MGS completed the fifth and sixth MOC Focus Calibrations. Both MOC Calibration Images hit the three targeted stars (Alcyone, Maia and Taygeta) with no image drops near the stars. Cross-track positions measured 2.1 - 2.2 milli-radians from the center on the same side of the detector as observed in previous star images. This is within the MGS pointing accuracy error budget.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 16 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads and the sequences cited above. There have been 4,891 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm077 background sequence will be uplinked on 00-280 (10/6/00). MOLA
Polar Scans, contained in the mz059 mini-sequence, will be performed on
00-281 (10/7/00) through 00-285 (10/11/00). Radio Science Occultation Egress
Scans, scheduled for 00-287 (10/13/00) and 00-288 (10/14/00), will be commanded
by the mz061 mini-sequence.
Launch / Days since Launch = Nov. 7, 1996 / 1421 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 545 days
Total Mapping Orbits = 6,959
Total Orbits = 8,562
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm072 sequence executed successfully from 00-265 (9/21/00) through 00-267 (9/23/00). The mm073 sequence has performed well since it started on 00-268 (9/24/00). It terminates on 00-271 (9/27/00). The mm074 sequence, successfully uplinked on 00-270 (9/26/00), begins executing on 00-272 (9/28/00).
Other - This week MGS completed the second, third, and forth of five scheduled MOC Focus Calibrations. The results of calibration #2 were inconclusive due to gaps in the data. The Deep Space Network antenna had difficulty maintaining the data downlink due to poor weather at the receiver site. MOC Focus Calibrations #3 and #4 were successful in imaging most of the targeted stars, providing scientists and engineers with data that will be used to improve the precision MOC targeting capabilities of MGS.
Spacecraft Health:
All subsystems report nominal health. During the beta-supplement phase of this mission we have been contending with the issue of how to retrieve from MGS all of the science and engineering data that is recorded. We knew that eventually planetary position geometry combined with the need to maneuver the spacecraft around the HGA gimbal obstruction would result in our inability to playback all of the data within the available downlink windows. We have attempted two modifications in the Solid State Recorder (SSR) record/playback strategy over the past weeks. The modification that works the best is analogous to pressing the "pause" button on a typical tape recorder. So, every time we playback SSR Track 7, we command the SSR to "pause" just before MGS becomes occulted by Mars or it maneuvers around the HGA gimbal obstruction. We pick up the playback of SSR Track 7 during the next downlink opportunity. Presently, it takes three separate downlink opportunities to playback SSR Track 7 completely. With less than 45 minutes of each 2 hour orbit available for playback, it already takes 12 downlink opportunities over 6 complete orbits to playback SSR Tracks 1 through 6. Therefore, MGS requires 15 - 16 hours of downlink each day to playback all recorded data. This situation will gradually improve as planetary geometry becomes more favorable. The beta-supplement phase of this mission ends in late June of 2001.
Uplinks:
There have been 13 uplinks to the spacecraft during the last week, including instrument command loads and sequences cited above. There have been 4,875 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm075 background sequence will be uplinked 00-273 (9/29/00). MOC
Focus Calibration #5 contained in the mz058 mini-sequence, will be performed
on 00-272 (9/28/00). An additional MOC Focus Calibration (#6) is scheduled
for 00-277 (10/3/00) to gain the data lost during MOC Focus Calibration
#2. It's uplink designation will be mz060. MOLA Polar Scans, contained in
the mz059 mini-sequence, will be performed 00-281 (10/7/00) through 00-285
(10/11/00). Radio Science Occultation Egress Scans are scheduled for 00-287
(10/13/00) and 00-288 (10/14/00).
Launch / Days since Launch = Nov. 7, 1996 / 1414 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 538 days
Total Mapping Orbits = 6,874
Total Orbits = 8,477
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm070 sequence executed successfully from 00-258 (9/14/00) through 00-260 (9/16/00). The mm071 sequence has performed well since it started on 00-261 (9/17/00). It terminates on 00-264 (9/20/00). The mm072 sequence, successfully uplinked on 00-263 (9/19/00), begins executing on 00-265 (9/21/00).
Other - MGS successfully completed the first of five MOC Focus Calibrations on 00-262 (9/18/00). The MOC focus calibration image contained the three targeted stars (Alcyone, Maia and Taygeta). Downtrack position was good and crosstrack position improved from previous calibrations.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 17 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4,862 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm073 background sequence will be uplinked 00-266 (9/22/00). MOC
Focus Calibrations #2 - #5, contained in the mz057 and mz058 mini-sequences,
will be performed 00-266 (9/22/00) through 00-272 (9/28/00). MOLA Polar
Scans will be performed 00-281 (10/7/00) through 00-285 (10/11/00). They
will be contained in the mz059 mini-sequence.
Launch / Days since Launch = Nov. 7, 1996 / 1407 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 531 days
Total Mapping Orbits = 6,788
Total Orbits = 8,391
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm068 sequence executed successfully from 00-251 (9/7/00) through 00-253 (9/09/00). The mm069 sequence has performed well since it started on 00-254 (9/10/00). It terminates on 00-257 (9/13/00). The mm070 sequence, successfully uplinked on 00-256 (9/12/00), begins executing on 00-258 (9/14/00).
Other - MGS successfully completed twelve Radio Science Occultation Egress Scans, between 00-252 (9/8/00) and 00-253 (9/09/00). They were contained in the mz055 mini-sequence. Scientists are analyzing the resulting data set.
Spacecraft Health:
All subsystems report nominal health. Because MGS is approaching aphelion, the average energy margin per orbit has been dropping as expected. Two new solar array motion scripts, designed to increase power margin, began operating on 00-251 (9/7/00). The spacecraft is now maintaining 60 Watt-hours of average energy margin per orbit compared to 35 Watt-hours just before the new scripts took effect. We expect the spacecraft to maintain an average energy margin per orbit greater than 40 Watt-hours through aphelion.
Uplinks:
There have been 15 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4,845 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm071 background sequence will be uplinked 00-259 (9/15/00). MOC Focus Calibrations, scheduled for 00-262 (9/18/00) through 00-272 (9/28/00), will be contained in the mz056, mz057, and mz058 mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1400 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 524 days
Total Mapping Orbits = 6,703
Total Orbits = 8,306
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm066 sequence executed successfully from 00-244 (8/31/00) through 00-246 (9/02/00). The mm067 sequence has performed well since it started on 00-247 (9/3/00). It terminates on 00-250 (9/6/00). The mm068 sequence, successfully uplinked on 00-249 (8/5/00), begins executing on 00-251 (9/7/00).
Other - Between 00-243 (8/30/00) and 00-246 (9/2/00) MGS specifically targeted the North and South poles with the laser altimeter during thirteen orbits covering 360 degrees of latitude. Now that the mz054 MOLA Polar Scan mini-sequence has successfully terminated, scientists are processing the resulting data set.
Spacecraft Health:
All subsystems report nominal health. As MGS approaches aphelion, the average energy margin per orbit is dropping as expected. Two new solar array motion scripts have been uplinked to maintain 40 Watt-hours of average energy margin per orbit while MGS travels near aphelion. They take effect on 00-251 (9/7/00).
Uplinks:
There have been 17 uplinks to the spacecraft during the last week, including instrument command loads, the previously cited background sequences, the two new solar array motion scripts, and the mz055 mini-sequence. The mz055 mini-sequence will command Radio Science Occultation Egress Scans between 00-252 (9/8/00) and 00-253 (9/09/00).
There have been 4,830 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm069 background sequence will be uplinked 00-252 (9/8/00). MOC Focus Calibrations, scheduled for 00-262 (9/18/00) through 00-272 (9/28/00), will be contained in the mz056, mz057, and mz058 mini-sequences.
Launch / Days since Launch = Nov. 7, 1996 / 1393 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 517 days
Total Mapping Orbits = 6,617
Total Orbits = 8,220
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm064 sequence executed successfully from 00-237 (8/24/00) through 00-239 (8/26/00). The mm065 sequence has performed well since it started on 00-240 (8/27/00). It terminates on 00-243 (8/30/00). The mm066 sequence, successfully uplinked on 00-242 (8/29/00), begins executing on 00-244 (8/31/00).
Other - The mz054 mini-sequence containing the MOLA Polar Scans was uplinked 00-241 (8/28/00). Between 00-243 (8/30/00) and 00-246 (9/2/00) MGS will specifically target the North and South poles with the laser altimeter during thirteen orbits covering 360 degrees of latitude.
Spacecraft Health:
All subsystems report nominal health. As MGS approaches aphelion, the average energy margin per orbit is dropping as expected. Power projections indicate that the average energy margin per orbit will drop below the 40 Watt-hour threshold between early September 2000 and mid-January 2001. Though the spacecraft is capable of operating nominally below this threshold, the project has elected to maintain the average energy margin at or above 40 Watt-hours. The on-board command scripts that control solar array motion will be modified to provide the desired margin. This change will take effect 00-251 (9/7/00).
Uplinks:
There have been 9 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4,813 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm067 background sequence will be uplinked 00-245 (9/1/00). Radio Science Occultation Egress Scans, scheduled for 00-252 (9/8/00) through 00-253 (9/09/00), are contained in the mz055 mini-sequence. It will be uplinked 00-250 (9/6/00). MOC Focus Calibrations are scheduled for 00-262 (9/18/00) through 00-272 (9/28/00).
Launch / Days since Launch = Nov. 7, 1996 / 1379 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 503 days
Total Mapping Orbits = 6446
Total Orbits = 8049
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm060 sequence executed successfully from 00-223 (8/10/00) through 00-225 (8/12/00). The mm061 sequence has performed well since it started on 00-226 (8/13/00). It terminates on 00-229 (8/16/00). The mm062 sequence, successfully uplinked on 00-228 (8/15/00), begins executing on 00-230 (8/17/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 14 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4788 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm063 background sequence will be uplinked 00-231 (8/18/00). MOLA
Polar Scans are scheduled for 00-243 (8/30/00) through 00-246 (9/2/00).
Launch / Days since Launch = Nov. 7, 1996 / 1372 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 496 days
Total Mapping Orbits = 6360
Total Orbits = 7963
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm058 sequence executed successfully from 00-216 (8/03/00) through 00-218 (8/05/00). The mm059 sequence has performed well since it started on 00-219 (8/06/00). It terminates on 00-222 (8/09/00). The mm060 sequence, successfully uplinked on 00-222 (8/09/00), begins executing on 00-223 (8/10/00).
The spacecraft successfully completed twelve Radio Science Occultation Egress Scans on 00-221 (8/8/00) and 00-222 (8/9/00). The AACS performed well using the same off-NADIR pointing scheme that proved successful last May.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 9 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4774 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm061 background sequence will be uplinked 00-224 (8/11/00). MOLA Polar Scans are scheduled for 00-242 (8/29/00) through 00-246 (9/2/00).
Launch / Days since Launch = Nov. 7, 1996 / 1365 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 489 days
Total Mapping Orbits = 6274
Total Orbits = 7877
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm056 sequence executed successfully from 00-209 (7/27/00) through 00-211 (7/29/00). The mm057 sequence has performed well since it started on 00-212 (7/30/00). It terminates on 00-215 (8/02/00). The mm058 sequence, successfully uplinked on 00-214 (8/01/00), begins executing on 00-216 (8/03/00).
On 00-214 (8/01/00), the MOLA was turned on as part of the mm057 sequence. It had been off for a two-month period that included Solar Conjunction. MOLA laser transmitter life is directly related to its on-time. We plan to double its remaining useful life by operating the instrument every other month.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. There have been 4765 command files radiated to the spacecraft since launch.
Upcoming Events:
The mz053 mini-sequence will be uplinked 00-216 (8/03/00). It contains the Radio Science Occultation Egress Scans that will take place on 00-221 (8/8/00) and 00-222 (8/9/00). The mm059 background sequence will be uplinked 00-217 (8/04/00).
Launch / Days since Launch = Nov. 7, 1996 / 1358 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 482 days
Total Mapping Orbits = 6189
Total Orbits = 7792
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm054 sequence executed successfully from 00-202 (7/20/00) through 00-204 (7/22/00). The mm055 sequence has performed well since it started on 00-205 (7/23/00). It terminates on 00-208 (7/26/00). The mm056 sequence, successfully uplinked on 00-207 (7/25/00), begins executing on 00-209 (7/27/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 13 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. On 00-203 (7/21/00) we successfully demonstrated the capability to perform uplinks using the new DSS-14 X-band transmitter. There have been 4752 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm057 background sequence will be uplinked 00-210 (7/28/00). The MOLA will be turned-on on 00-214 (8/1/00). Radio Science Occultation Egress Scans will take place 00-221 (8/8/00) and 00-222 (8/9/00).
Launch / Days since Launch = Nov. 7, 1996 / 1351 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 475 days
Total Mapping Orbits = 6103
Total Orbits = 7706
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm052 sequence executed successfully from 00-195 (7/13/00) through 00-197 (7/15/00). The mm053 sequence has performed well since it started on 00-198 (7/16/00). It terminates on 00-201 (7/19/00). The mm054 sequence, successfully uplinked on 00-200 (7/18/00), begins executing on 00-202 (7/20/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 12 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, MOC turn-on commands, instrument command loads, and the background sequences cited above. There have been 4739 command files radiated to the spacecraft since launch.
Upcoming Events:
The mm055 background sequence will be uplinked 00-203 (7/21/00).
Launch / Days since Launch = Nov 7, 1996 / 1344 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 468 days
Total Mapping Orbits = 6017
Total Orbits = 7620
Recent Events:
Background Sequences -- We are in the last day of the Solar Conjunction phase of the mission and sequences continue to execute nominally. The mm051 sequence will terminate and the mm052 sequence will begin on 00-195 (7/13/00). mm052, the first beta-supplement sequence to execute since 00-174 (6/22/00), will start recording science data on 00-195 (7/13/00). Playbacks of science data commence on 00-196 (7/14/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 10 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files and the mm052 background sequence. We turned off two-way non-coherent mode to regain two-way Doppler capability and we set the Command Loss Timer to its nominal value of 104 hours. The total number of command files radiated to the spacecraft since launch is 4727.
Upcoming Events:
The MOC will be turned on tomorrow, 00-195 (7/13/00), via real-time commands. The mm053 background will be uplinked 00-196 (7/14/00).
Launch / Days since Launch = Nov 7, 1996 / 1337 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 461 days
Total Mapping Orbits = 5932
Total Orbits = 7535
Recent Events:
Background Sequences -- We are in the Solar Conjunction phase of the mission. The mm050 sequence is progressing nominally. The mm051 sequence will commence on 00-190, (7/8/00).
Spacecraft Health:
All subsystems report nominal health. We saw the noise in the downlink signal increase as the Sun-Earth-Mars (SEM) angle approached the minimum value of 0.87 degrees on 00-183 (7/1/00). We received no telemetry from 00-181 (6/29/00) through 00-183 (7/1/00) due to Solar Conjunction. Now, the downlink signal is gradually improving as the SEM angle increases.
Uplinks:
No commands were uplinked this week. Total command files radiated to the spacecraft since launch is 4717.
Upcoming Events:
We expect to return to normal spacecraft configuration and beta-supplement command sequences starting with the mm052 sequence on 00-195 (7/13/00). We continue to monitor spacecraft health and the actual vs. predicted timing of orbital events. The spacecraft attempts to contact Earth during three of the twelve orbits each day during the Solar Conjunction period. When the downlink signal is good, we receive engineering telemetry and the actual Mars equator crossing time for that orbit. We compare the actual equator crossing time with the predicted equator crossing time to determine the accuracy with which we placed spacecraft maneuvers. We expect the accuracy of our orbital timing to degrade with time. Tracking the rate at which the timing degrades helps us ensure the spacecraft health during the Solar Conjunction. We are prepared to cancel or rebuild stored sequences if timing degradation reaches unacceptable levels. Presently our predictions deviate from actual orbit timing by less than twenty-two seconds. This is well within the established timing envelope. Timing would have to deviate by 75 seconds before we considered canceling the stored sequence. We anticipate satisfactory timing throughout the remainder of mm050 and mm051. We expect to obtain satisfactory two-way Doppler tracking data on 00-190 (7/8/00). Orbital timing estimates will return to normal in the week following. Sequence development of mm052 and mm053 is proceeding nominally.
Launch / Days since Launch = Nov 7, 1996 / 1330 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 454 days
Total Mapping Orbits = 5846
Total Orbits = 7449
Recent Events:
Background Sequences -- The mm050 and mm051 Solar Conjunction sequences were uplinked successfully and the MOC was turned off by commands in the mm049 sequence. The mm050 sequence became active on 00-175 (6/23/00). We are now in the Solar Conjuction phase of the mission.
Spacecraft Health:
All subsystems report nominal health. We are seeing more noise in the downlink signal as the Sun-Earth-Mars angle decreases. This is expected. The Sun-Earth-Mars angle will reach a minimum of 0.87 degrees on 00-183 (7/1/00). The downlink signal will gradually improve with time beyond that date.
Uplinks:
Only one file was uplinked to the spacecraft during the last week. It was the mm051 sequence. Total command files radiated to the spacecraft since launch is 4717.
Upcoming Events:
We expect to return to normal spacecraft configuration and beta-supplement command sequences starting with the mm052 sequence on 00-195 (7/13/00). Until then, we will monitor spacecraft health and the actual vs. predicted timing of orbital events. The spacecraft attempts to contact Earth during three of the twelve orbits each day during the Solar Conjunction period. When the downlink signal is good, we receive engineering telemetry and the actual Mars equator crossing time for that orbit. We compare the actual equator crossing time with the predicted equator crossing time to determine the accuracy with which we placed spacecraft maneuvers. We expect the accuracy of our orbital timing to degrade with time. Tracking the rate at which the timing degrades will help us ensure the spacecraft health during the next few weeks. We are prepared to cancel or rebuild stored sequences if timing degradation reaches unacceptable levels. Presently our predictions deviate from actual orbit timing by less than six seconds. This is well within the established parameters (Gee, I sound like Data). Once the spacecraft emerges from Solar Conjunction and we are able to obtain two-way Doppler tracking data, our orbital timing estimates will return to normal.
Launch / Days since Launch = Nov 7, 1996 / 1316 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 440 days
Total Mapping Orbits = 5674
Total Orbits = 7277
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The mm046 background sequence executed successfully from 00-160 (6/08/00) through 00-163 (6/11/00). The mm047 background sequence has been performing nominally since 00-164 (6/12/00) and will terminate at the end of day 00-166 (6/14/00). The mm048 sequence was successfully uplinked on 00-165 (6/13/00) and will begin executing on 00-167 (6/15/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 17 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. Total command files radiated to the spacecraft since launch is 4702.
Upcoming Events:
We are in the final stages of Solar Conjunction command sequence generation
and testing. The mm050 and mm051 sequences will contain the lion's share
of spacecraft commands for the Solar Conjunction period, 6/21/00 through
7/12/00. To prepare for Solar Conjunction, the MOC will be turned off using
commands resident in the mm049 sequence. We expect to return to normal spacecraft
configuration and beta-supplement command sequences starting with mm052
on 00-195 (7/13/00).
Launch / Days since Launch = Nov 7, 1996 / 1309 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 433 days
Total Mapping Orbits = 5589
Total Orbits = 7192
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The following background sequences executed successfully: mm042 from 00-146 (5/25/00) through 00-149 (5/28/00); mm043 from 00-150 (5/29/00) through 00-152 (5/31/00); mm044 from 00-153 (6/01/00) through 00-156 (6/04/00); and mm045 from 00-157 (6/05/00) through 00-159 (6/07/00). The mm046 sequence was successfully uplinked on 00-158 (6/06/00) and will begin executing on 00-160 (6/08/00).
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 19 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. Total command files radiated to the spacecraft since launch is 4685.
Upcoming Events:
Normal beta-supplement sequences are planned between now and Solar Conjunction. We are in the initial stages of Solar Conjunction command sequence generation and testing. The mm050, and mm051 sequences will contain the lion's share of spacecraft commands for the Solar Conjunction period, 6/21/00 through 7/12/00. There will be some spacecraft configuration commands related to Solar Conjunction contained in the mm049 and mm052 sequences.
Launch / Days since Launch = Nov 7, 1996 / 1295 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 419 days
Total Mapping Orbits = 5418
Total Orbits = 7021
Recent Events:
Background Sequences -- The spacecraft continues to operate nominally in performing the beta-supplement daily recording and transmission of science data. The following background sequences executed successfully: mm038 from 00-132 (5/11/00) through 00-135 (5/14/00); mm039 from 00-136 (5/15/00) through 00-138 (5/17/00); mm040 from 00-139 (5/18/00) through 00-142 (5/21/00); and mm041 from 00-143 (5/22/00) through 00-145 (5/24/00). The mm042 sequence was successfully uplinked on 00-144 (5/23/00) and will begin executing on 00-146 (5/25/00).
Science Experiments - Three science experiment campaigns took place during the past two weeks. They were Bistatic Radar, MOLA Off-NADIR Polar Scans, and Radio Science Occultation Egress Scans. Commands for the Bistatic Radar experiment were included in the mm038 sequence as part of DOY 135 activities. Commands for the MOLA Off-NADIR Polar Scans composed the mz051 mini-sequence. They executed over 11 consecutive orbits on DOY 138 and DOY 139. Finally, MGS performed Radio Science Occultation Egress Scans on DOY 141,142, and 143 according to the mz052 mini-sequence. Overall, spacecraft performance during all experiments was nominal. The following paragraphs provide additional information regarding AACS performance.
In the MOLA experiment, we used the same CSA offset quaternions as the previous two polar opportunities. The SARBES (Starex reset) command was eliminated from this sequence and replaced with a general memory load of high rate gyro bias estimates and a separate software command to load the high rate steady state gyro biases. We also retained the divided North and South Pole slews implemented with the last MOLA polar opportunity. We are happy to report that the Starex problems observed in previous MOLA polar experiments have disappeared. Starex performance was completely, totally, and utterly nominal. Slew performance was superb, as it was for the previous polar experiments.
For the first time during a Radio Science Occultation Egress experiment, we used an Off-NADIR pointing scheme. AACS performance proved nominal, comparing well with predicts. Again, Starex performed superbly, converging in 10 stars. We successfully used the same method of gyro bias loading in the Radio Science experiment that we used in the MOLA Polar Scan experiment. Preliminary results indicate that the science teams received useful data during these experiments. Therefore, we plan to use the same spacecraft pointing and sequence development techniques for future MOLA and Radio Science experiments.
Spacecraft Health:
All subsystems report nominal health.
Uplinks:
There have been 28 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, and the background sequences cited above. Total command files radiated to the spacecraft since launch is 4666.
Upcoming Events:
Normal beta-supplement sequences are planned between now and Solar Conjunction.
We are in the final stages of Solar Conjunction planning. The mm050 sequence
will cover the Solar Conjunction period between 6/21/00 and 7/12/00.
Launch / Days since Launch = Nov 7, 1996 / 1281 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 405 days
Total Mapping Orbits = 5250
Total Orbits = 6853
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm036 sequence executed successfully from 00-125 (5/4/00) through 00-128 (5/7/00). The mm037 sequence also successfully executed from 00-129 (5/8/00) through 00-131 (5/10/00). The mm038 sequence was successfully uplinked on 00-130 (5/9/00) and will begin execution on 00-132 (5/11/00).
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 16 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm037 and mm038 sequences. Total command files radiated to the spacecraft since launch is 4638.
Upcoming Events:
A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is in final development and will execute on May 14. The commands to perform this experiment have been incorporated into the mm039 sequence, which is scheduled to be uplinked on 00-134 (5/13/00)
The next monthly MOLA off-nadir polar scan mini-sequence (mz051) is also in final development and will execute over 12 consecutive orbits beginning on May 17.
The implementation of the first Radio Science occultation egress scans, replacing the previous fixed-HGA periods for obtaining occultation egress data, is also in development at this time and is scheduled for execution on 5/20-5/22/00.
Launch / Days since Launch = Nov 7, 1996 / 1274 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 398 days
Total Mapping Orbits = 5164
Total Orbits = 6767
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm034 sequence executed successfully from 00-118 (4/27/00) through 00-121 (4/30/00). The mm035 sequence also successfully executed from 00-122 (5/1/00) through 00-124 (5/3/00). The mm036 sequence was successfully uplinked on 00-123 (5/2/00) and will begin execution on 00-125 (5/4/00).
The mz050 mini-sequence, containing the retry of the two missed MOC focus star scans, successfully executed on 4/28 and 4/30. The updated quaternion for these scans correctly accounted for the bias error due to the IMU being commanded to high rate mode and resulted in the stars being correctly centered in the image.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 11 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm035 and mm036 sequences. Total command files radiated to the spacecraft since launch is 4622.
Upcoming Events:
A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is in final development and will execute on May 14.
The next monthly MOLA Off-Nadir Polar Scans is about to begin development. The scans are scheduled for 12 consecutive orbits beginning on May 17.
The implementation of the first Radio Science occultation egress scans,
replacing the previous fixed-HGA periods for obtaining occultation egress
data, is also on schedule for execution on 5/20-5/22/00.
Launch / Days since Launch = Nov 7, 1996 / 1267 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 391 days
Total Mapping Orbits = 5078
Total Orbits = 6681
Recent Events:
MGS reached the 5000 mapping orbit milestone on 00-111 (4/20/00) at 12:31:55 UTC.
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm032 sequence executed successfully from 00-111 (4/20/00) through 00-114 (4/23/00). The mm033 sequence also successfully executed from 00-115 (4/24/00) through 00-117 (4/26/00). The mm034 sequence was successfully uplinked on 00-116 (4/25/00) and will begin execution on 00-118 (4/27/00). The mz050 mini-sequence, containing the retry of the two missed MOC focus star scans on 4/28 and 4/30, is scheduled for uplink on 00-118 (4/27/00).
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 19 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm033 and mm034 sequences. Total command files radiated to the spacecraft since launch is 4611.
Upcoming Events:
A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is on schedule for execution on 5/14/00.
The implementation of the first Radio Science occultation egress scans,
replacing the previous fixed-HGA periods for obtaining occultation egress
data, is also on schedule for execution on 5/20-5/22/00.
Launch / Days since Launch = Nov 7, 1996 / 1260 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 384 days
Total Mapping Orbits = 4992
Total Orbits = 6595
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm030 sequence executed successfully from 00-104 (4/13/00) through 00-107 (4/16/00). The mm031 sequence also successfully executed from 00-108 (4/17/00) through 00-110 (4/19/00). The mm032 sequence was successfully uplinked on 00-108 (4/17/00) and will begin execution on 00-111 (4/20/00).
A retry of the two missed MOC focus star scans is scheduled for 4/28 and 4/30. The second attempts will utilize an updated scan attitude to account for the gyro bias error propagated when the IMU is switched from low rate to high rate mode for the slews.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 11 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm032 and mm033 sequences. Total command files radiated to the spacecraft since launch is 4592.
Upcoming Events:
A bistatic radar experiment, in which the Spacecraft signal will be reflected off the Martian surface to Earth, is on schedule for execution on 5/14/00, upon Project approval expected next week.
The implementation of the first Radio Science occultation egress scans,
replacing the previous fixed-HGA periods for obtaining occultation egress
data, are also on schedule for execution on 5/20-5/22/00.
Launch / Days since Launch = Nov 7, 1996 / 1253 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 377 days
Total Mapping Orbits = 4906
Total Orbits = 6509
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm028 sequence executed successfully from 00-97 (4/6/00) through 00-100 (4/9/00). The mm029 sequence also successfully executed from 00-101 (4/10/00) through 00-103 (4/12/00). The mm030 sequence was successfully uplinked on 00-102 (4/11/00) and will begin execution on 00-104 (4/13/00).
Included in the mm028 sequence, was the fifth and last star scan of the current MOC focus campaign, and a 24-hour period of MOLA off-nadir scans of the North and South Poles, on 00-99 through 00-100 (4/8-4/9/00). The spacecraft performance during the final MOC star scan was nominal, but the stars were not seen in the image. Thus two of the five scans resulted in not seeing the stars. All indications are that the missed stars were due to a knowledge error in designing the scans. A retry of the two missing star scans will be scheduled for later in April, with an updated scan attitude.
Spacecraft performance during the MOLA scans was also nominal, with a single STAREX (star processing code) anomaly occurring proceeding the first MOLA off-nadir orbit. A STAREX autonomous reset occurred shortly after the sequence commanded the IMU to high rate mode and issued an intentional bias reset prior to the first off-nadir slew. After the autonomous reset STAREX converged properly and performed nominally for the duration of the MOLA scans.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 16 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm030 and mm031 sequences. Total command files radiated to the spacecraft since launch is 4581.
Upcoming Events:
Planning for the replacement of the monthly fixed-HGA periods for the
purpose of obtaining radio science atmospheric occultation egress data,
prohibited in normal beta supplement operations due to HGA gimbal constraints,
proceeds. The first Radio Science occultation egress scans are scheduled
for 5/20-5/22/00. Work has been underway over the last month on determining
the feasibility of performing a bistatic radar experiment, in which the
Spacecraft signal will be reflected off the Martian surface to Earth. All
design hurdles have been cleared and work is now underway to implement this
experiment for a May 14 opportunity.
Launch / Days since Launch = Nov 7, 1996 / 1245 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 370 days
Total Mapping Orbits = 4820
Total Orbits = 6423
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm026 sequence executed successfully from 00-90(3/30/00) through 00-93 (4/3/00). The mm027 sequence also successfully executed from 00-94 (4/4/00) through 00-96 (4/6/00). The mm028 sequence was successfully uplinked on 00-95 (4/5/00) and will begin execution on 00-97 (4/8/00). Included in the mm028 sequence, is the fifth and last star scan of the current MOC focus campaign, and a 24-hour period of MOLA off-nadir scans of the North and South Poles, scheduled on 00-99 through 00-100 (4/8-4/9/00). The mm029 sequence is scheduled to be uplinked on 00-99 (4/8/00) and will execute from 00-101 (4/10/00) through 00-103 (4/12/00).
The mz049 mini-sequence, containing the first four MOC star scans, has begun execution. The first three scans have completed to date. The MOC successfully acquired the desired stars from the first scan, but the stars were on the edge of their image. The second scan resulted in the MOC not seeing the stars. On the third scan the stars were acquired but were again on the edge of the image. The spacecraft attitude control errors were very small during each of the scans, leading us to believe there is some kind of knowledge error in the design of the scans, resulting in the stars not being centered in the image. AACS is currently analyzing the data and working with JPL and the MOC team to determine the cause of this error. Depending on the success of the fourth and fifth scans, additional scans may be performed in the next couple of weeks to ensure the MOC focus objective.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 14 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm028 and mm029 sequences. Total command files radiated to the spacecraft since launch is 4565.
Upcoming Events:
Planning for the replacement of the monthly fixed-HGA periods for the
purpose of obtaining radio science atmospheric occultation egress data,
prohibited in normal beta supplement operations due to HGA gimbal constraints,
proceeds. The first Radio Science occultation egress scans are scheduled
for 5/20-5/22/00.
Launch / Days since Launch = Nov 7, 1996 / 1241 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 363 days
Total Mapping Orbits = 4734
Total Orbits = 6337
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm024 sequence executed successfully from 00-83(3/23/00) through 00-86 (3/26/00). The mm025 sequence also successfully executed from 00-87 (3/27/00) through 00-89 (3/29/00). The mm026 sequence was successfully uplinked on 00-88 (3/28/00) and will begin execution on 00-89 (3/29/00). The mm027 sequence is scheduled to be uplinked on 00-92 (4/1/00) and will execute from 00-94 (4/3/00) through 00-96 (4/5/00). The mz049 mini-sequence, containing four MOC star scans for the purpose of improving the camera focus, was also uplinked successfully on 00-89 (3/29/00). The first star scan will occur on 00-90 at 14:35:56 GMT on the spacecraft.
The mm028 and mm029 sequences are currently in development. A fifth and final MOC focus star scan will be included in the mm028 sequence. It is intended to repeat the MOC focus scans every six months. Also included in the mm028 sequence is the next MOLA North and South Pole off-nadir scans. The MOLA polar scans will begin at approximately 12:00 GMT on 00-99 (4/8/00). The scans will take place over 12 consecutive orbits to provide complete longitudinal coverage of the poles.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 18 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm026, mm027 and mz049 sequences. Total command files radiated to the spacecraft since launch is 4551.
Upcoming Events:
Planning for the replacement of the monthly fixed-HGA periods for the purpose of obtaining radio science atmospheric occultation egress data, prohibited in normal beta supplement operations due to HGA gimbal constraints, proceeds.
Launch / Days since Launch = Nov 7, 1996 / 1234 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 356 days
Total Mapping Orbits = 4648
Total Orbits = 6251
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm022 sequence executed successfully from 00-75 (3/15/00) through 00-78 (3/18/00). The mm023 sequence also successfully executed from 00-79 (3/19/00) through 00-81 (3/21/00). The mm024 sequence was successfully uplinked on 00-81 (3/21/00) and began execution nominally on 00-82 (3/22/00). The mm025 sequence is scheduled to be uplinked on 00-85 (3/25/00) and will execute from 00-86 (3/26/00) through 00-88 (3/28/00).
Work has begun on the development of a series of MOC star scans to optimize the camera focus. Five total star scans of the Pleiades star cluster will be performed, one scan every other day, with the scan being done on the night-side of the orbit. The scans are currently scheduled on the days of 3/30, 4/01, 4/04, 4/05 and 4/07.
A series of FSW memory readout commands were performed over the last week and a half in order to determine the cause of an increased number of floating point overflow counts since the start of beta supplement operations. The results of the MROs determined that the overflows were coming from the polynomial evaluation function called by the articulation code and were a result of the HGA gimbals passing through 0 and 90 degrees, which is happening frequently during beta supplement due to the HGA management. The overflows appear to be benign and at this time, the SCT is still ascertaining whether any action is required.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 18 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm023 and mm024 sequences. Total command files radiated to the spacecraft since launch is 4533.
Upcoming Events:
MOLA Off-nadir North and South Pole scans scheduled for 4/8 and 4/9
Launch / Days since Launch = Nov 7, 1996 / 1227 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 349 days
Total Mapping Orbits = 4562
Total Orbits = 6165
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm020 sequence executed successfully from 00-63 (3/3/00) through 00-72 (3/12/00). The mm021 sequence also successfully executed from 00-63 (3/13/00) through 00-74 (3/14/00). The mm022 sequence was successfully uplinked on 00-73 (3/13/00) and began execution nominally on 00-74 (3/14/00).
Upon completion of the recent four day fixed-HGA mapping campaign performed last week, which resulted in higher than expected MOLA temperatures, the spacecraft team began looking at ways to fix the temperature problem. Additionally in assessing the first fixed-HGA campaign, it was noted that the actual transitions into and out of fixed-HGA mode of operations from the beta supplement mode of operations, were more complicated than anticipated and resulted in a larger than expected loss of science data from the other instruments. The Spacecraft Team presented at the 3/14 Project Mission Planning meeting alternatives to and options for fixing the current fixed-HGA operations. Fixed-HGA operations were to be performed 4-8 days per month for the express purpose of acquiring Radio Science Earth occultation egress measurements, which are prohibited during normal beta supplement mapping operations due to HGA gimbal constraints. From the Mission Planning meeting the favored option was to eliminate the fixed-HGA operations and perform special slews for a specified number of orbits to provide the desired longitudinal planetary coverage for the radio science occultation egress data, similar to the implementation of the MOLA off-nadir polar observations. Final details are in work and will be presented to the Project Change Board next Tuesday (3/21)
Spacecraft Health:
All subsystems are reporting nominal health. Battery 2 was successfully commanded back to VT-2 after transitioning back to beta supplement operations. The red alarm high limit for the MOLA temperature has been decreased by 3 degrees (from 35°C to 32°C) after a meeting with the MOLA engineers.
Uplinks:
There have been 20 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm021 and mm022 sequences. Two uplinks were missed after the final transition from the fixed-HGA Earth pointed attitude back to nadir pointed beta supplement operations due to a large change in the transponder temperature. The uplink sweeps for the beta supplement orbits are tailored specially for the very short uplink windows and are very sensitive to changes in the MOT temperature. The missing uplinks were successfully re-radiated. Total command files radiated to the spacecraft since launch is 4515.
Upcoming Events:
Planning has begun for a focus calibration of the MOC to be performed in late March.
Launch / Days since Launch = Nov 7, 1996 / 1220 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 342 days
Total Mapping Orbits = 4476
Total Orbits = 6158
Recent Events:
The spacecraft continues to operate nominally in performing the beta supplement daily recording and transmission of science data. The mm018 sequence executed successfully from 00-62 (3/2/00) through 00-65 (3/5/00).
The mm019 sequence (i.e. first fixed-HGA sequence) began execution on 00-65 (3/5/00) and will run through completion of 00-68 (3/8/00). The mm019 sequence contains 12 orbits of MOLA off-nadir polar scans followed by three consecutive days of eight hour fixed-HGA Earth pointed periods, designed to allow radio science Earth occultation egress data, which is prohibited during beta supplement operations due to HGA boom and EMI interference constraints. Two incidents have occurred on the spacecraft during the execution of this sequence, as described below. The next sequence mm020 (another beta supplement sequence), scheduled to execute from 00-69 (3/9/00) through 00-72 (3/12/00), has been successfully uplinked to the spacecraft.
The first incident of the mm019 sequence was with star processing during the MOLA off-nadir Polar scans. The first 12 orbits of the mm019 sequence flew with a -17.1° nadir off-point angle for 45 minutes centered about the South Pole and a 14.4° nadir off-point angle for 45 minutes centered about the North Pole. This left about 30 minutes of star processing time per two-hour orbit. Anticipating that the limited star processing might be problematic, based on the previous MOLA polar scans performed last year, two things were done to ensure that the spacecraft would not lose inertial reference and enter contingency mode fault protection. First a commanded bias reset was issued two hours before the first MOLA scan to coincide with the IMU swap to high rate mode and second the lost logic limit, the number of unidentified stars allowed before an autonomous bias reset, was raised to 60 stars. Twice during the 12 orbit scan sequence, the lost logic limit was exceeded and an autonomous reset was commanded. After each reset the spacecraft successfully converged attitude. Three consecutive cumulative resets are required to actually cause entry into contingency mode. Prior to slewing the spacecraft to the first fixed-HGA Earth pointed attitude following the MOLA scans, the spacecraft attitude was nominal and star processing was properly converged. In spite of the star processing problems, the spacecraft successfully executed all of the slews and returned the data back to Earth, during the subsequent eight hour fixed-HGA Earth pointed period.
The second incident occurred when the MOLA laser temperature approached the 35° upper flight allowable limit, during the last orbit of the second eight-hour fixed-HGA Earth pointed period. The increased temperature was expected but the actual temperatures were about four degrees higher than that predicted by the thermal model. Real-time telemetry was not available for the flight team during the Earth pointed period, which is used for playback of the recorded data. The greater than expected temperature increase was noticed in the playback data on the third and last fixed-HGA Earth pointed period.
The Spacecraft Team is currently reassessing the monthly MOLA off-nadir polar orbit scans and the fixed-HGA Earth periods for radio science egress data, to determine what changes are required to ensure the safety of all the instruments and robustness of the spacecraft in performing these special events. Options will be presented to the Project at the 3/14 Mission Planning meeting. The next fixed-HGA sequence is scheduled for 00-076 (3/16/00) and will most likely be replaced with a beta supplement sequence.
Spacecraft Health:
All subsystems are reporting nominal health. As expected the battery DOD was greater during the four fixed-HGA Earth pointed orbits due to the additional transmitter on time associated with performing the radio science occultation egress event. As a result battery 2 autonomously switched to the VT 1 curve. Upon completion of the fixed-HGA sequence, battery 2 will be commanded back to VT 2.
Uplinks:
There have been 15 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm020 sequence. Total command files radiated to the spacecraft since launch is 4495.
Upcoming Events:
Planning has begun for a focus calibration of the MOC to be performed
in late March.
Launch / Days since Launch = Nov 7, 1996 / 1213 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 335 days
Total Mapping Orbits = 4390
Total Orbits = 6072
Recent Events:
The spacecraft continues to operate nominally in performing the daily recording and transmission of the science data. The mm016 sequence executed successfully from 00-55 (2/24/00) through 00-58 (2/27/00). The mm017 sequence began execution on 00-59 (2/28/00) and will run through completion of 00-61 (3/1/00). The next sequence mm018, scheduled to execute from 00-62 (3/2/00) through 00-64 (3/4/00), has been successfully uplinked to the spacecraft.
The first fixed-HGA sequence of the beta supplement mapping phase, mm019, has been generated and will be uplinked Saturday March 4. The mm019 sequence will begin execution on 00-65 and continue through 00-68 (3/8/00). Included in the mm019 sequence is the first of the monthly off-nadir polar scans for the MOLA instrument, approved by the Program. The first 12 orbits of the mm019 sequence will fly with a -17.1 degree nadir off-point angle for 45 minutes centered about the South Pole and a 14.4 degree nadir off-point angle for 45 minutes centered about the North Pole. For the fixed-HGA mapping operations, the spacecraft will be nadir pointed for 24 hours, recording science data on the solid state recorders, then the spacecraft will be oriented to point the HGA bore-sight at Earth for an eight hour playback period to return the data collected on the recorders. During this eight-hour period, the spacecraft will not be nadir pointed and not collecting science data, with the exception of radio science which will perform atmospheric observations as the spacecraft enters and exits Earth occultation. As reported last week the reason for the fixed-HGA sequences is to provide radio science atmospheric observations near the South Pole as the spacecraft exits Earth occultation, a geometry not supported by the HGA gimbals in the beta supplement operations due to EMI and HGA boom interference constraints. Upon completion of the data playback at the end of the eight-hour Earth pointed period, the spacecraft will be turned back to nadir pointing to begin the next fixed-HG A cycle
Spacecraft Health:
All subsystems are reporting nominal health. Three more PDS reset occurred over the last week. The frequency has been increasing over the last two weeks. So far no cause has been found for the recurring resets. The resets appear to have minimal if any impacts to the instruments. We continue to forward all reset data to the PDS software experts at JPL.
Uplinks:
There have been 21 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm017 and mm018 sequences. Total command files radiated to the spacecraft since launch is 4480.
Upcoming Events:
The Navigation team has been looking at the ground track walk on a weekly basis to determine if an orbit trim maneuver (OTM) is required. Prior to the start of beta supplement operations, it appeared that an OTM would be needed sometime in March. However, the latest tracking data for the first few weeks of beta supplement operations shows the rate of the ground track walk decreasing and starting to knee over, which if the trend continues will not necessitate an OTM in the near term. With the likelihood of the next OTM diminishing, planning has begun for a focus calibration of the MOC to be performed in the next few weeks.
Launch / Days since Launch = Nov 7, 1996 / 1206 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 328 days
Total Mapping Orbits = 4305
Total Orbits = 5987
Recent Events:
The pace of the new mapping Beta sequence generation problem, a build
every week, and a realization of new operational constraints imposed by
the new mapping scheme, has caused two sequencing errors over the last week.
On 00-048 (2/17/2000) at about 00:00 UTC, the new Beta Supplement sequence,
mm014b, was scheduled to kickoff but never went active. Since that new sequence
controls the tracking of the HGA to Earth, no downlink was possible. Using
a 34-m HEF station, a command was successfully uplinked via LGR-2 to change
the uplink rate from 125 bps to 7.8 bps. Then, at 7.8 bps, a mini-sequence
was successfully radiated to auto-track the HGA for about 30 minutes per
orbit for 4 consecutive orbits, allowing for a 4K real-time downlink. During
the first of these orbits, spacecraft telemetry was obtained which showed
that MGS was in a healthy condition. During the second of these orbits,
the uplink rate was changed back to 125 bps and the new mm014c sequence
was uplinked to resume normal operations. The mm014c sequence began execution
nominally at 14:20 UTC and has successfully completed execution. The mm015
sequence, was uplinked and began execution on 00-051 (2/20/2000) at 00:00
UTC. The mm015 sequence is scheduled to run through 00-054 (2/23/2000).
The net effect of the anomaly was the loss of most of DOY 48 recorded science
telemetry.
The cause of the mm014 sequence anomaly was that it was loaded into the
incorrect area of the sequence buffer, which was already executing the mm013
sequence. This error was induced by having to split the 7 day beta supplement
sequence into two parts due to the size of the sequence and the much reduced
uplink time available each orbit due to the complex HGA management. This
splitting process introduced an ambiguity in the naming convention: mm013a
was used for Part 1 of sequence 013 rather than revision level a, and mm013b
was used for Part 2 of sequence 013 rather than revision level b. When a
second revision of Part 1 was required, mm013c was used, since mm013b was
already taken by Part 2. Due to the ambiguity in the naming convention,
mm014 was run through SEQTRAN using the FINCON file from mm013c (Part 1)
rather than mm013b (Part 2). The result was that mm014b was loaded into
the same buffer area as Part 2 of the previous sequence. Since this previous
sequence was still executing when mm014b was uplinked, the new sequence
did not go active.
To confound matters, due to the current MGS to Earth range, we are not
able to support two-way data (uplink and downlink data) at the high rate
40 ksps real-time downlink rate. Therefore all uplinks are currently performed
during orbits in which the recorded data from the previous day is being
played back. Therefore confirmation of a successful sequence uplink and
activation requires waiting until the next day's data is played back. For
this case there was insufficient time available to determine that the sequence
load had been rejected and to rebuild a replacement sequence in time. This
was due in part to a half-day loss in the schedule due to a problem with
our spacecraft test lab (STL).
The second anomaly occurred with the development of the mm016a sequence,
which was uplinked successfully to the spacecraft on 00-052 (2/21/200) and
scheduled to begin execution on 00-055 (2/24/00) at 00:00 UTC. In this event
an error in the recording and playback of the science data was discovered
after the sequence had been uplinked. The sequence was successfully terminated
on 00-054 (2/23/2000) at ~14:00 UTC and a replacement sequence, mm016b,
uplinked several orbits afterwards upon confirmation of the termination
of mm016a. The root cause for this anomaly was simply a rush to uplink the
sequence early enough to verify its activation in order to avoid a repeat
of the mm014 sequence anomaly.
Several changes have been made to the sequence development process for the weekly sequence builds. The first change, which was already going to be made for the next sequence anyhow, was to rename the sequences. The split of the weekly sequences into two parts creates two sequences, mm016 and mm017, for example, rather than mm016a and mm016b. The second and probably the most important change made was to increase the sequence development time by three days to provide sufficient time with margin for development, review, STL validation, uplink and verification of the sequences.
One final note, the failure to get a new sequence on-board the spacecraft poses no risk to the health of the spacecraft. The spacecraft will maintain mapping nadir pointing and articulation of the solar array. Communications from the spacecraft and collection of science data will be interrupted until a new sequence can be uplinked.
Spacecraft Health:
All subsystems are reporting nominal health. A sixth PDS reset occurred on 00-019. So far no cause has been found for the recurring resets. The resets appear to have minimal if any impacts to the instruments. We continue to forward all reset data to the PDS software experts at JPL.
Uplinks:
There have been 14 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm014, mm015 and mm016 sequences. Total command files radiated to the spacecraft since launch is 4459.
Upcoming Events:
The first fixed-HGA mapping sequence of the beta supplement era is scheduled for March 6 and development of this sequence has begun. One of the limitations of the mapping beta supplement scheme is a loss of South Pole radio science atmospheric data due to HGA gimbal constraints. The project approved a three to four day period each month to perform fixed-HGA operations, in which the HGA is pointed along the spacecraft +X axis and the spacecraft is moved to point the HGA to Earth for an eight-hour period (i.e. four orbits). During the eight-hour Earth pointed period the science data recorded from the previous 24 hours of nadir pointed mapping is played back. This scheme allow radio science observations to be made at Earth occultation ingress and egress, at the expense of collecting mapping data for the eight-hour Earth pointed period. The project also approved monthly MOLA nadir off-pointed polar observations. These observations will be performed during the 24 hour nadir pointing period prior to the first eight-hour fixed-HGA Earth pointed period.
Launch / Days since Launch = Nov 7, 1996 / 1199 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 321 days
Total Mapping Orbits = 4219
Total Orbits = 5901
Recent Events:
Beta Supplement operations continue nominally. The mm013 sequence is currently executing on the spacecraft. The next sequence, mm014, was uplinked to the spacecraft on Feb 15 at 18:25 GMT and is scheduled to go active at 00:00 GMT on Feb 17.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 30 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm013 sequence. Total command files radiated to the spacecraft since launch is 4445.
Upcoming Events:
The first fixed-HGA mapping sequence of the beta supplement era is scheduled for March 6. More details forthcoming.
Launch / Days since Launch = Nov 7, 1996 / 1190 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 314 days
Total Mapping Orbits = 4134
Total Orbits = 5816
Recent Events:
The mz041 mini-sequence, containing the "full-up" Beta Supplement HGA motion verification test, executed on Thursday Feb 3 at ~11:00 GMT. The test successfully moved the azimuth gimbal to 140°, then performed a "simulated orbit" on the elevation gimbal, incorporating a 3-part boom interference rewind and a 3-part range-of-motion rewind, and executed the full elevation range of motion from -157° to +155°. Based upon the success of the test, the first beta supplement mapping sequence, mm012, was radiated to the spacecraft and began executing Saturday Feb 4 at 00:00 GMT. The first beta supplement orbit executed on Monday Feb 7 at 10:00 GMT and all operations on the spacecraft and with the DSN station were completely nominal. Twenty-five orbits have been successfully executed as of the writing of this report.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 25 uplinks to the spacecraft during the last week, including new star catalogs and ephemeris files, instrument command loads, and the mm012 sequence. Total command files radiated to the spacecraft since launch is 4415.
Upcoming Events:
Uplink of the second beta supplement sequence, mm013, is scheduled for
Thursday Feb 10.
Launch / Days since Launch = Nov 7, 1996 / 1169 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 293 days
Total Mapping Orbits = 3876
Total Orbits = 5558
Recent Events:
The mm011 sequence began execution on Jan 13 at 00:00 UTC and runs through Feb 4. The spacecraft continues to perform flawlessly in performing the nominal mapping mission.
The mz035 mini-sequence, containing scans for a third Pathfinder landing site image and two additional MPL landing site images finished execution on Jan 19 at 13:45 UTC. Unfortunately, bad luck struck again with regard to the Pathfinder opportunity and significant portions of the Pathfinder image were lost due to more DSN problems. There is no redundant capability to return the imaging data at the high 40000 bps real-time rate and also record the data to the solid state recorders for redundant playback the next day. Consequently, return of these landing site images is a single opportunity event which requires the DSN stations to be configured and working properly during the ~30 minute data return period. Hardware, weather and other factors with the stations contribute to make this far from a foolproof process. In general, the DSN has performed excellently in supporting the MGS mission.
A change request was approved by the Project to perform some HGA motion calibration tests for the Magnetometer team. These will be performed on the dark side of the planet and will have minimal effect on normal operations. The only exception is that Radio Science ingress data will be prematurely truncated on the calibration orbits. These HGA motions tests will be performed over 15 orbits, with the solar arrays being moved to different fixed positions during the HGA motions after every three orbits. Due to mini-sequence buffer size constraints, the 15 orbits will be performed in two parts. The mz036 mini-sequence was successfully transmitted to the spacecraft on Jan 19, to perform the first 9 orbits on Jan 20 and mz037 will be transmitted on Jan 21 to perform the remaining 6 orbits on Jan 21.
The Ka Band Link Experiment (KaBLE) was turned off on Jan 14, to reduce the spacecraft power loads. The KaBLE investigators are not currently utilizing the Ka Band data.
HGA Anomaly:
The HGA inner gimbal continues to decrease and is currently at 48.9 degrees. The inner gimbal angle will continue decreasing, reaching the location of the gimbal obstruction at 41.5 deg in early February. A special review was held on Jan 18 to discuss possible spacecraft testing to determine if the obstruction is still present. The recommendations from the review are expected by the end of the week. Any spacecraft testing would be performed over the next two weeks, prior to the start of beta supplement mapping operations.
Spacecraft Health:
All subsystems are reporting nominal health. A third Payload Data System (PDS) reset occurred on Jan 16. The reset data has been sent to JPL, who designed and built the PDS. The spacecraft team has been unable to correlate the data to any specific spacecraft activity.
Uplinks:
There have been 27 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads, KaBLE turn off and the mz036 mini-sequence load. Total command files radiated to the spacecraft since launch is 4345.
Upcoming Events:
The preliminary first beta supplement sequence will begin development Jan 20 in preparation for the start of beta supplement mapping operations on Feb 5. Additional MPL and MPF imaging opportunities will continue through Feb 4. The next imaging mini-sequence will be built on Jan 21 and will contain all the desired over-flight opportunities through Jan 26.
Wednesday, January 12, 2000 (DOY 005/19:00:00 to DOY 012/19:00:00 UTC)
Launch / Days since Launch = Nov 7, 1996 / 1162 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 286 days
Total Mapping Orbits = 3791
Total Orbits = 5473
Recent Events:
The mm010 sequence finishes execution on Jan 13 at 01:27 UTC. The next mapping sequence, mm011, has been uplinked to the spacecraft and will begin execution on Jan 13 at 00:00 UTC and continue executing through Feb 4. The mm011 sequence will be the last nominal mapping sequence of the baseline mapping mission. The next mapping sequence will be the first of the new beta supplement sequences, designed to continue mapping operations in the presence of the HGA obstruction at the 41.5 deg azimuth gimbal angle. Stay tuned for more information about the specifics of beta supplement mapping operations over the next few weeks
The mz034 mini-sequence was uplinked to the spacecraft on Jan 8 and finished execution on Jan 12 at 09:00 UTC. The mz034 sequence contained the second imaging scan of the Pathfinder landing site and four additional scans of the Mars Polar Lander landing site. The additional MPL landing site scans are intended to fill in gaps in the original imaging campaign performed prior to the holidays and to expand the coverage area to the west in response to the latest atmospheric data. Unfortunately bad luck asserted itself again on the second Pathfinder landing site image as the science data was lost due to DSN station problems. A third attempt to image the Pathfinder site is currently being planned. Additional imaging of the MPL landing site is currently being discussed to continue expanding the coverage area.
The spacecraft continues to behave flawlessly in performing nominal mapping operations and the multitude of imaging scans.
HGA Anomaly:
The HGA inner gimbal continues to decrease and is currently at 51.7 degrees. The inner gimbal angle will continue decreasing, reaching the location of the gimbal obstruction at 41.5 deg in early February. STL testing to validate the new beta supplement operations plan continues.
Spacecraft Health:
All subsystems are reporting nominal health.
Uplinks:
There have been 18 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files, instrument command loads and the mm011a and mz034a sequences. Total command files radiated to the spacecraft since launch is 4318.
Upcoming Events:
1) The mm012 sequence development kickoff meeting is scheduled for Jan 18.
2) The mz035 mini-sequence to continue imaging the MPL and MPF landing sites is scheduled for development on January 13 and 14.
3) The mz036 mini-sequence to perform additional magnetometer instrument calibrations has been approved and will begin development Jan 17.
Launch / Days since Launch = Nov 7, 1996 / 1155 days
Start of Mapping / Days since Start of Mapping = April 1, 1999 / 279 days
Total Mapping Orbits = 3707
Total Orbits = 5389
Recent Events:
The mm010 sequence continues executing nominally the daily science record and playback events. The mm010 sequence runs through January 12.
The initial MPL landing site imaging campaign has been completed, with 19 targeted scans across the predicted 1-sigma MPL landing ellipse having been executed. Unfortunately no obvious signs of the lander or its parachute has been found at this time. Note that the definition of the landing ellipse continues to change as additional atmospheric data from MGS is factored in. As a result, the current landing site imaging mosaic may not reflect the latest landing site knowledge. Additionally there were some gaps in the mosaic due to lost data at the DSN stations. As a result, a second set of imaging scans is being planned to fill in the gaps and to expand the coverage area in response to the latest atmospheric data.
In addition to completing the MPL scans, a special targeted opportunity to image the Mars Pathfinder landing site was performed Sunday December 26 at 09:18 UTC. Unfortunately due to an error in the coordinate system used to derive the targeted attitude, the wrong site was imaged. A second opportunity to image the Pathfinder landing site occurs on Sunday January 9. The mz034 mini-sequence will be built on January 6 and 7 to perform the MPF and additional MPL landing site imaging, and will execute through January 12.
The spacecraft has behaved almost flawlessly in performing all of the imaging scans.
HGA Anomaly:
The HGA inner gimbal angle continues to decrease and is currently at 53.5 degrees. The inner gimbal angle will continue decreasing, reaching the location of the gimbal obstruction at 41.5 deg in early February. STL testing begun for validation of the HGA beta supplement operations plan, which will be used to perform mapping operations for the rest of the nominal mapping mission.
Spacecraft Health:
All subsystems are reporting nominal health. As reported previously, battery 2 switched from VT curve 2 to VT curve 1 as a result of performing the MPL scans. This was expected and resulted in slightly higher battery 2 temperatures. Upon completion of the initial MPL and MPF scans, the Battery 2 VT curve was switched back to VT2. Soon after though the flight software autonomously re-commanded battery 2 back to VT1, which is where we will leave it. The trend indicates that battery 1 will shortly switch to VT1 as well.
Uplinks:
There have been 42 uplinks to the spacecraft during the last two weeks, including new star catalogs and ephemeris files and instrument command loads. Total command files radiated to the spacecraft since launch is 4300.
Upcoming Events:
1) The mm011 sequence is currently in development and is scheduled for uplink Monday January 10, with a sequence start time of January 13 00:00 UTC.
2) The mz034 sequence to continue imaging the MPL and MPF landing sites is scheduled for development on January 6 and 7, to begin execution on Sunday January 9.
MSOP-MGS Status Reports for 1999