|
Date
(UARS day)
|
Date
(day-month-year)
|
Date
(year-day of year)
|
Event
|
|
1
|
12 September 1991
|
1991-255
|
UARS launch
|
|
18
|
29 September 1991
|
1991-272
|
HRDI activated
|
|
18-51
|
29 September 1991 - 1 November 1991
|
1991-272 thru 1991-305
|
Do not process HRDI winds or temperatures before version
'J'
coefficients are used
|
|
52
|
2 November 1991
|
1991-306
|
HRDI useful scientific measurements began – version
'J' coefficients are loaded
|
|
52-77
|
2 November 1991 - 27 November 1991
|
1991-306 thru 1991-331
|
Do not process HRDI stratospheric winds or aerosols due to
problems with the scene selector
|
|
78
|
28 November 1991
|
1991-332
|
Modified HRDI modes to use the same side of the scene
selector. Modification remains
in effect for rest of mission
|
|
154
|
12 February 1992
|
1992-043
|
Standardize mesosphere lines used by HRDI to 13138, 13076,
13043, 13041 cm-1
|
|
181
|
10 March 1992
|
1992-070
|
Change HRDI stratospheric mode to use one line (b or gamma
band) in a limb scan
|
|
201
|
30 March 1992
|
1992-090
|
Replaced HRDI use of 13043 cm-1 weak line,
which was contaminated by potassium emission, with 13052 cm-1 weak
line. HRDI MRE post 2 partial failure – addressed by changing
instrument programming.
|
|
265
|
2 June 1992
|
1992-154
|
UARS solar array drive initial failure. HRDI was not
turned on again until day 310.
|
|
282-283
|
19/20 June 1992
|
1992-171/172
|
HRDI temperature reached -18.5oC
|
|
458
|
12 December 1992
|
1992-346
|
Extend HRDI mesospheric altitude range to 50 – 115
km
|
|
510
|
2 February 1993
|
1992-033
|
HRDI MRE post 1 partial failure – instrument
programming was updated to work around this problem – slew data are not
scientifically useful after this date, since the slew time was used for
re-tuning the instrument
|
|
583
|
16 April 1993
|
1993-106
|
UARS horizon sensor failed
|
|
590
|
23 April 1993
|
1993-113
|
Modify HRDI thermal control to set the radiator to -10oC
at night and -7.5o at day.
Before this the radiator was held at -10oC
|
|
620
|
23 May 1993
|
1993-143
|
Replace use of 13041 cm-1 weak line with 13052
cm-1 weak line for HRDI
|
|
642
|
14 June 1993
|
1993-165
|
Implement revised temperature control for HRDI. If MRE bulk temperature is greater
than -8.5oC, then set the radiator temperature to -12.5oC;
otherwise set it to -7.5oC
|
|
691
|
2 August 1993
|
1993-214
|
Start improved temperature control for HRDI. If bench temperature 2 is greater
than -8.5oC, then set the radiator temperature to -12.5oC;
otherwise set it to -7.5oC
|
|
693
|
4 August 1993
|
1993-216
|
UARS solar array drive second failure – HRDI
re-started on day 698.
|
|
737
|
17 September 1993
|
1993-260
|
UARS solar array drive third failure. Array (and HRDI) was
re-started after a week.
|
|
752
|
02 October 1993
|
1993-275
|
UARS solar array drive anomaly. HRDI re-started day 775.
|
|
996
|
03 June 1994
|
1994-154
|
Begin using mesosphere combined wind/photometric mode at
night for HRDI.
|
|
1087
|
2 September 1994
|
1994-245
|
Update UARS Fixed Head Star Tracker (FHST) scale
factors/offsets at 15:42 UT
|
|
1220/1221
|
13/14 January 1995
|
1995-013/014
|
UARS solar array drive anomaly – HRDI off about 8
hours
|
|
1289
|
23 March 1995
|
1995-082
|
UARS Earth sensor problem – HRDI off until day 1304
|
|
1314
|
17 April 1995
|
1995-107
|
UARS solar array drive ceased rotation – HRDI off
until day 1392
|
|
1372/1373
|
14/15 June 1995
|
1995-165/166
|
HRDI temperature reached -21oC
|
|
1392
|
4 July 1995
|
1995-185
|
Began reduced frequency of operation for HRDI due to lack
of power available on spacecraft
|
|
1475
|
25 September 1995
|
1995-268
|
Update UARS FHST 1 offsets and/or scale factors
|
|
1477
|
27 September 1995
|
1995-270
|
UARS Narrow Band Tape Recorder (NBTR) A increased noise
starts – NBTR B is used for much of the data hereafter
|
|
1775
|
21 July 1996
|
1996-203
|
UARS battery 1 failed
|
|
1821
|
5 September 1996
|
1996-249
|
Update UARS FHST 1 scale factors
|
|
2004
|
7 March 1997
|
1997-066
|
Turn off UARS FHST 1, use FHST 2.
|
|
2192
|
11 September 1997
|
1997-254
|
UARS epoch change
|
|
2287
|
15 December 1997
|
1997-349
|
UARS gyro anomaly
|
|
2577
|
1 October 1999
|
1998-274
|
Began continuous daytime operations for HRDI. By operating
only in the daylight parts of orbits, HRDI can be operated more often (ie
without relying on batteries).
|
|
2948
|
7 October 1999
|
1999-280
|
Partial failure of HRDI telemetry.
Caused some engineering values to be intermittently unreliable –
software was updated to compensate for this problem, but some data were
unrecoverable thru day 3019
|
|
2967
|
26 October 1999
|
1999-299
|
Initial indication of failure of UARS NBTR B (tape recorder). After
this, nearly all days have data gaps – some days are only 1/3 as large
as a full day. Much of the data is acquired directly thru TDRSS satellites.
|
|
3009
|
7 December 1999
|
1999-341
|
Modified HRDI modes to compare the actual filter position
to that desired to be sure filter wheels are in position. Before this, filter wheel were
operated open loop.
|
|
3019
|
17 December 1999
|
1999-351
|
Modified HRDI coefficients to remove effects of bad temperatures – assumes a
fixed temperature
|
|
3096
|
03 March 2000
|
2000-063
|
Upload revised HTC feedback for HRDI – ignores bad
temperatures
|
|
3122
|
29 March 2000
|
2000-089
|
Change HRDI instrument programming to correct for HRDI
instrument temperature at each terminator crossing
|
|
3123
|
30 March 2000
|
2000-090
|
Modified HRDI slew mode to compare the actual telescope
position with the desired to be sure telescope is in the desired
position. Before this, the telescope
was operated open loop. This was
implemented to account for the slowing and variable slew rate.
|
|
3190
|
5 June 2000
|
200-157
|
Update HRDI thermal control scheme – reported
instrument temperatures between -6 and -12 are assumed ok
|
|
3221
|
6 July 2000
|
2000-188
|
UARS star tracker 2 failed – use Fine Sun Sensor and
FHST 1. Attitude is less precise and stable, FHST 1 coefficients were updated
several times in the weeks that followed.
|
|
3306
|
29 September 2000
|
2000-273
|
UARS star tracker 1 turned off. After this the three axis
magnetometer (TAM) and solar sensors are used for attitude, attitude is less
precise and stable. Over the next few months, the TAM is adjusted several
times to try to upgrade it's results, with varying results.
|
|
3341-3359
|
03 November 2000 thru 21 November 2000
|
2000-308 thru 2000-320
|
UARS yawed to keep sun in solar sensor view (since TAM
isn't working well and star sensors are off).
|
|
3727
|
24 November 2001
|
2001-328
|
Last good stratospheric winds/aerosols measurement
|
|
4060
|
23 October 2002
|
2002-296
|
HRDI temperature reached -29.8oC
|
|
4089
|
21 November 2002
|
2002-325
|
Begin using 'overscan' mode for HRDI mesospheric
measurements, to make sure altitude range of interest is covered, since UARS
attitude is not precise
|
|
4950
|
31 March 2005
|
2005-090
|
Last HRDI science measurement
|
|
5208
|
14 December 2005
|
2005-348
|
UARS decommissioned
|
