Download - JWST FGS & TFI CVAC Risk Mitigation Tests
2011 March 17 1
JWST FGS & TFI CVAC Risk Mitigation Tests
Pierre Chayer, André Martel, Alex Fullerton, Ed Nelan, Kevin Volk, Anand
Sivaramakrishnan, Sherie Holfeltz, Comdev Canada, CSA, UdeM, HIA
2011 March 17 2
Fine Guidance Sensor (FGS) Optical Layout
2 m
100 mm
Pick-Off Mirror
TMA Mirrors
Focus Mirror
Detectors
Role of FGS: Provides centroids to the Attitude Control System.
2011 March 17 3
FGS Optical Assembly
2011 March 17 4
Tunable Filter Instrument (TFI) Optical Layout
Narrow Band Imager
2011 March 17 5
TFI Optical Assembly
Dual Wheel
CollimatorTMA
Camera TMA
Etalon
DetectorAssembly
KinematicMounts
2011 March 17 6
FGS & TFI Test Setup
2011 March 17 7
Chamber Darkness
2011 March 17 8
CVAC Risk Mitigation Test Objectives
• Verify modifications made to FSW for control of FGS.• Verify modifications made to FSW for image processing.• Continue with Risk Mitigation Activities for CVAC
Performance Test.– Collect data that can be used to mitigate risk for the CVAC
Performance Test in June.– Performance test for TFI without the Etalon.
• Complete Science Team Characterization activities
2011 March 17 9
CVAC Risk Mitigation Test
• 24 Day Test from January 10th to February 3rd.
• Test Started – January 10th 2011• Cool-down Started – January 10th 2011• Stable at 37 K – January 16th 2011• FGS Powered Down – January 22nd 2011• FGS Powered Up – January 25th 2011• Completion of Test Plateau – January 26th 2011• Warm-up Complete – January 29th 2011• Test Completed – February 3rd 2011
2011 March 17 10
G1 Best Focus
2011 March 17 11
FGS Cal Lamp
2011 March 17 12
G2 & G1 images with Cal Lamp
2011 March 17 13
Feature Observed in G1 Cal Images
Column (pixels)
Row
(pix
els)
FGSCVACG1PFMIFFF_6_497_SE_2011-01-22T04h23m11 CnS60
200 400 600 800 1000 1200 1400 1600 1800 2000
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400
600
800
1000
1200
1400
1600
1800
2000-300
-200
-100
0
100
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500
- Perhaps light exits the instrument, hits a reflective surface such as OGSE rack (only for G1) and re-enters to image the Cal source…? output?
Suggestion that the shape is reminisicent of the Cal source output? But how would that be imaged? Why only G1?
2011 March 17 14
Feature Observed in G1 Cal Images
It is theorized that light from the cal source may exit the instrument, reflect from an external surface (OGSE?) and re-enter, reflect from the cal source output, and be imaged on the detector.
Looking at the cal source testing, one can see a “jet” at the edge where the hemispheres join.
Is there an optical path for the “lines” to also show up in the image?
“Jet”
Column (pixels)
Row
(pix
els)
FGSCVACG1PFMIFFF_6_497_SE_2011-01-22T04h23m11 CnS60
200 400 600 800 1000 1200 1400 1600 1800 2000
200
400
600
800
1000
1200
1400
1600
1800
2000-300
-200
-100
0
100
200
300
400
500
2011 March 17 15
TFI Calibration Lamps
2011 March 17 16
TFI Cal Line
2011 March 17 17
Summary
• All objectives were completed with varying degrees of success.
• The team feels more confident to carry out the Proto-Flight CVAC Performance Test in June.
• The STScI team is looking forward to supporting the next round of tests.