| Date |
MOPITT Activity |
Instrument Anomaly Description |
| 1999/12/18 |
Launch | |
| 1999/12/18 - 2000/02/28 | Survival/Safe/Standby modes (initial
outgas/activation) | |
| 2000/02/28 | Doors
opened | |
| 2000/03/02 | Coolers on, Science
mode | |
| 2000/03/07 - 2000/03/22 | B&P
tests, Hot calibration (03/22,
03/23) | |
| 2000/03/23 - 2000/07/04 | Science
mode | |
| 2000/07/04 - 2000/07/14 | Hot
calibration, decontamination and Hot calibration (07/12,
07/13) | |
| 2000/07/14 - 2000/11/12 | Science
mode | |
| 2000/11/12 - 2000/11/17 | Hot
calibration (11/14), baseline LMC and burstmode
data | |
| 2000/11/17 - 2001/2/6 | Science
mode | |
| 2001/02/04 - 2001/02/15 | Hot
calibration, decontamination and Hot calibration (02/15,
02/16) | |
| 2001/02/16 - 2001/05/06 | Science
mode | |
| 2001/05/07 | Side B Cooler
Failure (channels 1-4 no longer usable) | MOPITT used two coolers, each of which were composed of a
linear compressor motor and a linear displacer motor, connected with a
gas tube. A cold finger mounted on the displacer was used to acheive
detector cooling, and the two coolers were operated in anti-phase to
minimize compressor-driven vibraitions. In May 2001, the side B
dispalcer hit the end stop, causing the cooler subsystem to shut
down. Diagnosis revealed that the side B displacer was unresponsive to
commands but was being driven by pressure waves from the side B
compressor. This inhibited cooling to the side B detectors (channels
1-4), rendering their measurements non-viable. Due to the anti-phase
operations of the twinned coolers, cooler A could not be operated
independently which would cause vibrations in the system. Thus,
operation of the side B compressor was adjusted to compensate for
vibrations from compressor A, while maintaining a maximum amplitude
low enough to avoid having the side B displacer hitting the end
stop. Testing indicated that the side B compressor should be operated
at 82.5% of the nominal stroke. The side A compressor was also reduced
in amplitude slightly, while the Side A displacer was increased in
amplitude, the combined effect being an increase in the effective
cooling from side A with a reduction in the compressor-driven
vibrations. |
| 2001/08/04 | Chopper 3 Anomaly
(stay open) | Each MOPITT optical channel
began with a chopper, designed to allow for thermal drift calibration
in the instrument; however, operations showed that the spaceview is
sufficient to account for thermal drift in calibrations to the first
order. In 2001, chopper #3 failed, stopping completely and becoming
unresponsive to further commands. Fortunately, the chopper failed in
the open position. As the use of the chopper was deemed non-essential
to the collection of science-quality data, this had little effect on
the ongoing mission. |
| 2001/05/07 - 2001/08/24 | Standby
mode and Instrument tests (no
retrievals) | |
| 2001/08/25 - 2002/03/02 | Science
mode: Phase 2 (with channels
5-8) | |
| 2002/03/03 - 2002/03/04 | Hot
calibration | |
| 2002/03/19 - 2002/03/25 | Terra
Anomaly | During March 2002, a Terra
anomaly caused Terra and the instruments aboard, including MOPITT, to
enter SAFE mode. The satellite was recovered and MOPITT was set back
into SCIENCE mode with commanding in early March. |
| 2002/03/28 - 2002/03/30 | Hot
calibration | |
| 2002/04/06 | Mirror #1
Anomaly | In April 2002, Mirror 1
completely failed, becoming unresponsive to commands. As this was on
the non-operating side B of MOPITT this did not affect the collection
of science data. |
| 2002/11/30 - 2002/12/12 | Hot
calibration, decontamination and Hot calibration
(12/12) | |
| 2002/12/13 - 2002/12/18 | Standby
mode (cooler off) | In December 2002, the
MOPITT side B displacer hit the end stop, causing a cooler
shutdown. The cooler subsystem was brought back online with the same
settings as after the May 2001 cooler subsystem failure. While the
side B detectors remained non-operational due to their temperatures,
scientific operation of the side A detectors continued after this
anomaly with little impact. |
| 2002/12/19 - 2003/12/12 | Science
mode | |
| 2003/12/13 - 2004/01/02 | Anomaly, decontamination and Hot calibration
(2004/01/02) | During December 2003, a
Terra anomaly for an out-of-limits yaw rate caused Terra and the
instruments aboard including MOPITT to enter SAFE mode. The satellite
was recovered and MOPITT was set back into SCIENCE mode with
commanding in early January. |
| 2004/01/03 - 2004/06/08 | Science
mode | |
| 2004/06/09 - 2004/06/10 | Hot
calibration | |
| 2004/06/11 - 2005/01/18 | Science
mode | |
| 2005/01/19 - 2005/01/20 | Hot
calibration | |
| 2005/01/21 - 2005/04/24 | Science
mode | |
| 2005/04/25 - 2005/05/05 | Hot
calibration, decontamination and Hot calibration (05/04,
05/05) | |
| 2005/05/06 - 2006/10/01 | Science
mode | |
| 2006/10/02 - 2006/10/14 | Hot
calibration, decontamination and Hot calibration
(10/14) | |
| 2006/10/15 - 2008/01/28 | Science
mode | |
| 2008/01/29 - 2008/02/09 | Hot
calibration (01/30) and
decontamination | |
| 2008/02/10 - 2009/01/30 | Science
mode | |
| 2009/01/31 - 2009/02/11 | Hot
calibration, decontamination and Hot calibration
(02/10) | |
| 2009/02/12 - 2009/07/27 | Science
mode | |
| 2009/07/28 - 2009/09/29 | the
third Cooler Anomaly (no science data) | In
July 2009, the MOPITT side B displacer hit the end stop, causing a
cooler shutdown. The cooler subsystem was brought back online into a
similar state as it had been since the 2001 cryocooler failure but
with a slight reduction in the side B compressor amplitude, to 77.5
%. While the side B detectors remained non-operational due to their
temperatures, scientific operation of the side A detectors continued
after this anomaly with little impact. |
| 2009/09/30 - 2009/10/03 | Science
Mode | |
| 2009/10/03 | LMC3 Sieve Heater
Failure | The sieves are connected to the
LMC subsystems and act to buffer against changes in pressure in the
cells by changing the sieve body temperature. In October 2009, the
heater for Sieve 3 turned off spontanesouly, lowering the pressure in
LMC 3 by about 3.2 kPa. This drop was readily accounted for in the
data processing, and no impact on science data was found for this
anomaly once compensated for. In March 2011, the heater for Sieve 3
turned on again and resumed nominal operations, increasing the LMC
pressure, but again having no tangible effect on the science data once
the change had been compensated in the retireval
algorithm. |
| 2009/10/04 - 2010/01/19 | Science
Mode | |
| 2010/01/20 - 2010/01/21 | Hot
calibration | |
| 2010/01/22 - 2011/03/13 | Science
Mode | |
| 2010/12/02 - 2011/03/21 | LMC1
Sieve Heater Failure | In December 2010,
the heater for Sieve 1 turned off spontanesouly, lowering the pressure
in LMC1. As LMC1 is on the non-operational side of MOPITT, this did
not affect routine scientific operations. After MOPITT was reset
during the next decontamination, the heater was
reactivated. |
| 2011/03/14 - 2011/03/25 | Hot
calibration (03/14, 03/15), decontamination, Sieve Heater on again and
Hot calibration (03/25) | In October 2009,
the heater for Sieve 3 turned off spontanesouly, thereby lowering the
pressure in LMC 3 by about 3.2 kPa. In March 2011, the heater for
Sieve 3 turned on again and resumed nominal operations, increasing the
LMC pressure, but again having no tangible effect on the science data
once the change had been compensated in the retireval
algorithm. |
| 2011/03/26 - 2012/03/04 | Science
Mode | |
| 2012/03/05 - 2012/03/16 | Hot
calibration, decontamination and Hot calibration
(03/16) | |
| 2012/03/17 - 2013/03/24 | Science
Mode | |
| 2013/03/25 - 2013/04/05 | Hot
calibration, decontamination and Hot calibration
(04/05) | |
| 2013/04/06 - 2014/03/23 | Science
Mode | |
| 2014/03/24 - 2014/04/08 | Hot
calibration, decontamination, CPHTS and Hot calibration
(04/08) | |
| 2014/04/09 - 2015/03/22 | Science
Mode | |
| 2015/03/23 - 2015/04/03 | Hot
calibration, decontamination and Hot calibration
(04/03) | |
| 2015/04/04 - 2016/02/17 | Science
Mode | |
| 2016/02/18 - 2016/03/04 | Terra
Anomaly, decontamination and Hot calibration
(03/04) | During February 2016, a Terra
anomaly caused Terra and the instruments aboard, including MOPITT, to
enter SAFE mode. The satellite was recovered and MOPITT was set back
into SCIENCE mode with commanding in early March. |
| 2016/03/05 - 2017/03/05 | Science
Mode | |
| 2017/03/06 - 2017/03/17 | Hot
calibration, decontamination and Hot calibration
(03/17) | |
| 2017/03/18 - 2018/03/11 | Science
Mode | |
| 2017/12/12 - 2018/03/19 | LMC1
Sieve Heater Failure | In December 2017,
the heater for Sieve 1 turned off spontanesouly, lowering the pressure
in LMC1. As LMC1 is on the non-operational side of MOPITT, this did
not affect routine scientific operations. After MOPITT was reset
during the next decontamination, the heater was
reactivated. |
| 2018/03/12 - 2018/03/23 | Hot
calibration, decontamination and Hot calibration
(03/23) | |
| 2018/03/24 - 2018/09/26 | Science
Mode | |
| 2018/09/27 - 2018/10/05 | Safe
Mode (cooler off) | During September 2018,
a Terra anomaly caused Terra and the instruments aboard, including
MOPITT, to enter SAFE mode. The satellite was recovered and MOPITT was
set back into SCIENCE mode with commanding in early
October. |
| 2018/10/06 - 2018/10/07 | Science
Mode | |
| 2018/10/08 - 2018/10/10 | Hot
calibration + Terra high gain antenna (HGA)
failure/recovery | |
| 2018/10/11 - 2019/03/10 | Science
Mode | |
| 2019/03/11 - 2019/03/23 | Hot
calibration, decontamination and Hot calibration
(03/22) | |
| 2019/03/24 - 2019/07/25 | Science
Mode | |
| 2019/07/26 - 2019/08/24 | SEU
Anomaly recovery, Hot calibration, decontamination and Hot calibration
(no valid MOPCH) | During July 2019, the
Sieve 4 heater turned off, causing the PMC2 amplitude to drop. After
MOPITT was rest, PMC 2 operations returned to normal, and scientific
operations could continue. During the latter part of this recovery
period, the first PMC 2 vibration event was observed. These irregular
(both in length and frequency) events would continue to affect MOPITT
until the PMC 2 failue in August 2024. During PMC 2 vibration events,
no science-quality data could be obtained. |
| 2019/08/25 - 2020/03/22 | Science
Mode | |
| 2020/03/23 - 2020/04/04 | Hot
calibration, decontamination and Hot calibration
(04/03) | |
| 2020/04/05 - 2021/03/24 | Science
Mode | |
| 2021/03/25 - 2021/04/13 | Hot
calibrations, decontamination and Hot
calibrations | |
| 2021/04/14 - 2022/06/05 | Science
Mode | |
| 2022/06/06 - 2022/06/18 | Hot
calibrations, decontamination and Hot
calibrations | |
| 2022/06/19 - 2022/10/02 | Science
Mode | |
| 2022/10/03 - 2022/10/29 | Hot
calibrations and Terra constellation exit maneuver
(CEM) | |
| 2022/10/30 - 2023/11/26 | Post-CEM Science Mode | |
| 2023/11/27 - 2023/12/09 | Hot
calibrations | |
| 2023/12/10 - 2024/08/11 | Post-CEM Science Mode | |
| 2024/08/11 - 2025/02/01 | PMC2
(channel 7) failure - impact to CO retrievals in upper
troposphere | Beginning 19 August 2019,
vibrations were observed in the MOPITT instrument originating from PMC
2. These vibration events were irregular both in duration and
frequency. In August 2024, the piston position for PMC 2 began varying
wildly, as did its driving current. This was accompanied by vibrations
in the system reminiscent of those observed during the PMC 2 vibration
events; however these vibrations were stronger in intensity. After a
few hours of this irregular behaviour, the piston position became
fixed, and the motor current began to increase, accompanied by an
increase in PMC 2 temperatures. PMC 2 was turned off, the vibrations
ceased, and the temperatures normalized. Several rounds of testing
were performed, using PMC 1 as a comparison, and PMC 2 clearly
illustrated that it was no longer capable of generating distinct
measurement states or operating as intended. The irregularity of the
piston response and the ensuing vibrations indcated that this was
likely a mechanical failure. Attempts to recover PMC 2 after the
MOPITT reset in November 2024 saw the issue persist to the point of a
complete mechanical failure in PMC 2. This failure renderes channel 7
inoperable, but does not effect channel 5 and 6, thus permitting
scientific operations to continue, albeit with a change to the
measurement products. |
| 2024/08/11 - 2024/11/11 | Post-CEM Science Mode without PMC
2 | |
| 2024/11/11 - 2024/11/23 | Hot
calibrations | |
| 2024/11/24 - 2024/12/27 | Post-CEM Science Mode without PMC
2 | |
| 2024/12/27 | MOPITT Side B
shutdown | In the latter part of the Terra
mission, several solar array shunts, which connect the solar panel
array to the batteries, failed and several displayed intermittent
issues. Alongside this, as the orbit of Terra drifts over time there
is a slow decrease in the amount of power generated from the solar
panels. With the loss of the most recent solar array shunt, Terra fell
into a power negative state requiring offloading some of the Terra
operations. ASTER was put into hiatus in early December 2024; however,
continually decreasing power margins and falling battery temperatures
required further load adjustments near the end of December 2024. To
help accomplish this, several of the Side B elements of MOPITT were
turned off. This included Chopper#1 and #2, Mirror#1 and #2, LMC#1 and
#2, Sieve#1 and #2, and PMC#1. As no observations are made with the
Side B detectors, this does not affect routine MOPITT
operations. |
| 2024/12/27-2025/02/01 | Post-CEM
Science Mode without PMC
2 | |
| 2025/02/01 | MOPITT
SAFE | With continually decreasing power
margins on the spacecraft, and continually falling bettery cell
temperatures in January, further load shedding was deemed essential in
January 2025. Due to the high power consumption of MOPITT compared to
the other Terra instruments, MOPITT was flagged to be put into SAFE
mode in order to save on power. While in SAFE mode, MOPITT does not
make scientific
measurements. |
| 2025/04/09 | MOPITT
OFF | Further power demands from the Terra
satellite and its instruments saw MOPITT put into SURVIVAL and then
finally turned OFF in April 2025, ending the MOPITT scientific data
record. |
