UARS MLS Operational History

Upper Atmosphere Research Satellite
Microwave Limb Sounder
Flight Operations Team

(still under constructionpeople at work image)

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Chronology of UARS MLS Scan mode changes
1991 Sep 12 UARS Launch from Cape Kennedy on Space Shuttle Discovery (STS-48) LAUNCH
1991 Sep 19 First day of useful atmospheric measurements MLSEQ0?
1991 Oct 17 MLS scan pattern changed to emphasize lower stratosphere, zero views once per orbit MLSEQ04
1991 Oct 31 Antenna Scan Bias added MLSEQ06
1991 Dec 4 Antenna Scan bias changes sign when oblateness changes direction MLNOM0
1992 Jan 14 MMIF 29 changed from a target view to a space view MLNOM0_B
1992 April 8 MLS oblateness correction resolution changed from 2.5 km to 1.25 km MLNOM0_C
1992 Sep 25 MLS science integration time changed from 1.792 to 1.728 sec
1992 Nov 16 MLNOM1_D
1993 Apr 24 MLS 183 GHz radiometer shut-off due to mixer failure
1993 May 19 MLNOM1_G
1993 May 27 MLNOM0_H
1993 Dec 23 MLS experiences first antenna scan actuator anomaly
1994 Jan 6 Scan program auto restart MLNOM0_I
1994 Jan 19 MLNOM1_J
1994 Apr 12 MLS intermittent operation due to scan anomalies
1994 Feb 3 Scan actuator heater management started
1994 Apr 12 MLS duty cycle reduced to preserve scan actuator life
1994 Oct 1 Scan anomalies recur, operation intermittent
1994 Nov 4 Closed loop scan started MLSCAN_T4
1995 Jan 25 Reverse scan started - eliminating scan anomalies MLREVSE0_C
1995 Feb 1 Limb track on low latitude turn around started on all full vertical scan days MLREVSE0_D
1995 Jun 3 Started 2 day full vertical scan and 1 day 18 km limb track scan as standard operating mode MLS1HT1_C
1996 Sep 22 Optimized limb tracking days for gravity wave measurments by using 2.5km oblateness correction MLS1HT1_E
1997 Jun 3 UARS Battery 1 declared failed, UARS begins two battery operation
1998 Jun 1 MLS experienced recurrence of scan slips.

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Chronology of UARS MLS Operational mode changes
1993 Apr 24 MLS 183 GHz radiometer shut-off due to mixer failure
1995 Feb 1 Limb track on low latitude turn around started on all full vertical scan days
1995 Jun 3 Started 2 day full vertical scan and 1 day 18 km limb track scan as standard operating mode
1996 Sep 22 Optimized limb tracking days for gravity wave measurments by using 2.5km oblateness correction
1998 Aug 3 Added auto restart and recovery from scan slips to maximize vertical scan attempts

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Chronology of UARS MLS Survival mode changes
1991 Sep 12UARS Launch from Cape Kennedy on Space Shuttle Discovery (STS-48)
1991 Sep 12Continuous Heater bus power
1993 Oct 3Cycled Heater bus power
1995 Jun 24Failed 183 GHz subsystem cycling for minimum peak power
1996 Aug 3Both Heater bus and Failed 183 GHz subsystem cycling for minimum S/C night power
1998 Move Heater bus and Op heater cycling from ATC to PMON & TMON processors

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Chronology of UARS MLS Special Tests
1991 Sep 15MLS initial in-orbit activation
1991 Sep 27MLS Characterization tests
1991 Sep 28MLS Characterization tests
1991 Sep 29MLS Characterization tests
1991 Sep 30MLS Characterization tests
1992 May 1UARS Disturbance TestMLJTR1_0
1992 Oct 11Moon Calibration TestMLMOON
1992 Dec 13Moon Calibration TestMLMOON2_1
1993 Jan 2Moon Calibration TestMLMOON2_2
1993 Apr 27183 GHz Mixer anomaly test #1
1993 Apr 29183 GHz Mixer anomaly test #2
1993 May 13183 GHz Mixer anomaly test #3
1993 May 27183 GHz Mixer anomaly test #4
1993 Jun 21183 GHz Mixer anomaly test #5
1993 Jul 8183 GHz Mixer anomaly test #6
1993 Jul 27183 GHz Mixer anomaly test #7
1993 Sep 3183 GHz Mixer anomaly test #8
1993 Sep 17183 GHz Mixer anomaly test #9
1993 Sep 17UARS Disturbance Test #2MLJTR1_1
1993 Dec 3Moon Calibration TestMLMOON2_4
1993 Dec 24Moon Calibration TestMLMOON2_5
1994 Mar 29Moon Calibration TestMLMOON2_6
1994 Sep 23Moon Calibration TestMLMOON?_7
1993 Nov 9183 GHz Mixer anomaly test #10
1993 Nov 30183 GHz Mixer anomaly test #11
1994 Dec 16Moon Calibration TestMLMOON1_A
1993 Dec 20183 GHz Mixer anomaly test #12
1994 Jan 5183 GHz Mixer anomaly test #13
1994 Jan 19183 GHz Mixer anomaly test #14
1994 Feb 4183 GHz Mixer anomaly test #15
1995 Mar 8Moon Calibration TestMLMOON2_8
1995 Mar 9Moon Calibration TestMLMOON3_8
1995 Mar 20Moon Calibration TestMLMOON???
1995 Mar 21Moon Calibration TestMLMOON???
1995 Dec 7Moon Calibration TestMLMOON???

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MLS Weekly Status Report  MLS ascii summary log  Latest Yaw maneuver information

This page maintained by Richard Lay. Last updated 22 January 1998.