MTA Monitoring Report 02/08/02 - 02/14/02

Archive of monthly reports

Radiation

Quiet

CTI Trend

Average of ACIS-I CCDs (MnKa) slope 1.173e-8 CTI/day
Detrended slope 1.129e-8 CTI/day

ACIS Warm Pixels

The following pixels consistently showed a bias level more than 5 sigma away the chip's mean level during this period.
We suspect some of the recurring bad pixels may be due to biases which are taken just after perigee, when the focal plane is somewhat warm. For more information see the link above and MTA monthly reports.

	CCD0	CCD2	CCD3	CCD4	CCD5	CCD6	CCD7	CCD8	CCD9
New this week/ Reappeared	(995,200)	(483,816)
Previously reported - still observed			(811,637)	(247,364)	(1-3,775-1024) (226,565) (226-245,313) (509,spurious rows) (510-511,775-1024) (512,775) (513,776-1024) (607,281) (1022,166)	(360,249) (766,501)	(1-3,1-114) (1-3,775-1024) (4,spurious rows) (509,spurious rows) (510-511,775-1024) (512,775) (513-515,775-1024) (516,spurious rows) (514,850) (514,940) (1021,1) (1021,198) (1021,408) (1021,684) (1022,775)	(62,482) (587,544) (952,1)	(150,373)
Previously reported - not observed during this period

ACIS Focal Plane Temperature

Day (DOY)	Temp (C)	Width (Days)
39.49	-113.73	0.58
42.16	-113.25	0.59
44.56/44.73	-117.93/-117.77	0.43	double peaks

SIM Movements

Telemetry

From SOT Shift Report

• Subject: Radiation timing in FEB1802 and FEB2502 loads
  Date: Tue, 12 Feb 2002
  FOT/MP (Kevin and Sabina) have discovered an important issue regarding radiation belts. The Chandra orbit has been evolving, and perigee is now above 18,000km. Because of the inaccuracy of the radiation model we are using at the Chandra distances from the earth, on day 63 and day 71 we see an absurdly short time (~45 min) from the predicted radiation entry until perigee. For now, the FOT will recognize these in advance, manually, by looking at their DSN contact graphic, which plots perigee and radiation belts. They can then take steps in the scheduling so that the OFLS gives sufficient time for the radiation entry; e.g., force it to be at least 5 hours before perigee. Bill Davis and CSC are looking into whether the SVERDRUP CRM will be more accurate -- we need to investigate. Backstop checking should probably provide a flag when the time of radiation entry or exit is less than 4 hours different from perigee."

  MTA is monitoring radiation zone entry times and intervals. We are upgrading this monitoring to attempt to detect multiple rad. zone entries.

  Davis Morris has performed a quick analysis of data for 2002. It looks like the AE-8 model is doing a pretty decent job of bracketing the high EPHIN radiation periods. There are no obvious trends in the relationship between the EPHIN data and the AE-8/AP-8 model predicted razone entry/exit times to explain the anomalously short entry time predicted during the FEB2502 schedule.

• Subject: Fid Lights
  Date: 14 Feb 02
  During the pass, the FOT noticed that the OBC was not using the fid light in slot 2. It registered a "defective pixel" flag. However, the camera is definitely tracking the fid light and telemetering the data. We can see that a warm pixel near the edge of the 8x8 track box might be biasing the centroid. Will there be a problem in the ground processing? We note that this warm pixel is near the fid due to the fact that we have a SIM-z offset for the HDF, to avoid having the HDF itself straddle the gaps in the ACIS-I array.

IRUs

• Gyro Bias Drift
• Gyro Bias Drift Histogram

Recent Observations

Ap has not run this week due to a new software release. All data reported below are based on manual processing. "Prob" means that there was probably bad time data included in the manual runs.

Trending

Note: Due to telemetry data problems, currently the trending page is not updated.

Daily average trends last reported on Nov 29 .
The most interesting trends are indicated with "*".

• Sim Thermal

  MSID	DESCRIPTION	COMMENTS
  3BTU_BPT	BTU BASEPLATE (+X)), ABORT HTR TSC2	scattered between 250 and 275, upward trend
  3FABRAAT	FA STRUCTURE +X FACE AT +Y+Z END ABORT	scattered between 262 and 274. slightly upward trend
  3FABRCAT	FA STRUCTURE +X FACE AT -Y-Z END ABORT	scattered between 265 and 290, slightly upward trend
  3FAMYZAT	FA STRUCTURE AT BEARING C ABORT HTR	scattered between 280 and 305
  3FAPYZAT	FA STRUCTURE AT BEARING A ABORT HTR	scattered between 286 and 298
  3FARALAT	FA STRUCTURE AT RAIL -Z, ABORT HEATER	scattered between 270 and 300
  3FLCABPT	FLCA BASEPLATE (+X)	scattered between 274 and 282, slightly increasing
  3RCTUBPT	RCTU BASEPLATE (+X)	scattered between 261 and 280, scattering widen
  3TSMXCET	-X TURTLE SHELL NR HRC CEA	scattered between 180 and 240
  3TSMXSPT	-X TURTLE SHELL NR ACIS SS	scattered between 230 and 260
  3TSMYDPT	-Y TURTLE SHELL NR ACIS DPA	scattered between 210 and 235
  3TSPYFET	+Y TURTLE SHELL NR HRC FEA	scattered between 220 and 240
  3TSPZDET	+Z TURTLE SHELL NR ACIS DEA	scattered between 250 and 270
  3TSPZSPT	+Z TURTLE SHELL NR ACIS SS	scattered between 255 and 271
  3TTACS1T	TT AT ACIS ATTACH #1, ABORT HTR	scattered between 262 and 270, slightly downward trend
  3TTACS2T	TT AT ACIS ATTACH #2, ABORT HTR TSC1	scattered between 260 and 270
  3TTACS3T	TT AT ACIS ATTACH #3, ABORT HTR TSC1	scattered between 260 and 262
  3TTBRGBT	TT AT BEARING B, ABORT HTR TSC4	scattered between 250 and 275, slightly upward trend
  3TTHRC1T	TT AT HRC BIPOD ATTACH #1	scattered between 255 and 285, scattering widen
  3TTHRC2T	TT AT HRC BIPOD ATTACH #2	262 and 285
  3TTHRC3T	TT AT HRC BIPOD ATTACH #3 & ACIS #4	scattered between 264 and 272
  3TTRALAT	TT AT RAIL A, ABORT HTR TSC3	around 250, some scattering to 230
  3TTRALCT	TT AT RAIL C, ABORT HTR TSC5	scattered between 258 and 274, slightly increasing
  3TTVALVT	TT AT VENT VALVE, ABORT HTR TSC7	scattered between 230 and 265
  BOXTEMP	SEA box temperature	scattered between 286 and 294
  FAMTRTEMP	FA motor temperature	around 287, some scattering to 276
  FLEXATEMP	Flexure A temperature	scattered between 273 and 282
  FLEXATSET	Flexure A temperature setpoint	around 210 and 275, more concentration on 275
  FLEXBTEMP	Flexure B temperature	scattered between 266 and 276, concentrating around 273/td>
  FLEXBTSET	Flexure B temperature setpoint	around 210 and 275
  FLEXCTEMP	Flexure C temperature	scattered between 275 and 300
  FLEXCTSET	Flexure C temperature setpoint	around 210 and 275
  PSUTEMP	SEA power supply temperature	scattered between 316 and 322
  TSCMTRTEMP	TSC motor temperature	scattered between 260 and 310, concentrating around 288

  
  
• Sim Electronics

  MSID	DESCRIPTION	COMMENTS
  AGRNDADC	Analog fround A/D convert reading	flat @ 0
  FATABADC	FA Tab Position Sensor A/D Converter	flat @5.0
  N15VADC	-15V power supply A/D conv. reading	flat @-15, -1, and 0
  P15VADC	+15V power supply A/D conv. reading	flat ~14.98
  P5VADC	+5V power supply A/D conv. reading	flat @4.95/4.96
  TSCTABADC	TSC Tab Position Sensor A/D Converter	flat @4.99

  
  
• Sim Actuator

  MSID	DESCRIPTION	COMMENTS
  FAEDGE	FA Tab Edge Detection Flags	flat @ 0.0
  FAPOS	FA position	mainly @ 0.0, but also -0.2, and ~-0.7
  FATABWID	Most recently detected FA tab width	flat @ 0.0
  LDRTNUM	FA Most Recent detected Tab Width	3 levels @, 1.0, 2.0, and 3.0
  LDRTRELPOS	Last detected ref tab relative position	3 levels around 0.0, 0.10, and 0.30
  MRMDEST	Most Recent Motor Move Destination	between 4.5 and 5, in log scale
  PWMLEVEL	max motor V PWM level most recent move	3 levels around 0.1, 0.6 and 2.0
  TSCEDGE	TSC Tab Edge Detection Flags	2 levels around 0 and 250
  TSCPOS	TSC position	4 levels around -260, 0, 200, 240
  TSCTABWID	Most recently detected TSC tab width	around 3.3 in log scale

  
  

• Sim Motions

  	DESCRIPTION	COMMENTS
  	Cumulative translation moves	~1110
  	Cumulative translation steps	~1.31e8
  	Time per translation step	0.00139 s, overall mission trend increasing by ~2.6e-8 s/s tep/day
  	Cumulative focus moves	~585
  	Cumulative focus steps	~2.25e5