Transcript SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA Last COS TIPS Aug TIPS 20 Nov 2003 COS Science Calibration & Instrument Status.

SPACE
TELESCOPE
SCIENCE
INSTITUTE
Operated for NASA by AURA
Last COS TIPS Aug
2003
TIPS
20 Nov 2003
COS Science Calibration
& Instrument Status
COS Instrument Status
• Thermal vacuum & science calibration testing complete
– Tests of mechanism stability continuing
• All important performance requirements have been met
–
–
–
–
–
Spectral resolution
Sensitivity
Flatfield quality
Scattered light
Wavelength coverage
• COS to be moved to GSFC for storage until launch preparation
– Periodic functional and throughput tests to verify instrument
health
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Thermal Vac & Science Calibration
• All testing completed at Ball Aerospace, Boulder
• Initial thermal balance tests and preliminary SI verification
(“Appendix A”) July 2-7.
– 21 tests. ~500 data files.
– Testing terminated to fix power converters and several other small
items.
• Detailed science calibration (“Appendix B”) Sept 20 – Oct 22.
– 109 tests. ~2200 data files.
– NUV first, FUV later, to allow pressure to drop to acceptable levels.
• OPUS and CALCOS processed data available with StarView.
• STScI support at Ball
– Keyes, Hartig, Sembach, Leitherer, Bohlin, Wheeler, D. Stys,
Friedman.
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COS Detectors
FUV XDL detector
NUV MAMA detector
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Vacuum Chamber Arrangement
COS operations
RAS/Cal
pumps
Vac chamber operations
Green Room contained
operations and data
analysis facility
COS
Vacuum chamber
Vacuum pump
RASCAL control
electronics & computer
Cal Delivery System
Calibration Delivery System
external platform provided
ultraviolet light sources.
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Science Calibration Test Categories
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Alignment, focus, image quality, resolution
Sensitivity
Wavelength scales
Stray & scattered light
Flat field and S/N
Detector functions
Optical stability & repeatability
Target acquisition algorithms
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Optical Layout
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Appendix B FUV Tests
test
number
70
2700
2705
2706
2740
850
2715
2725
2710
2726
2740
3600
1700
1210
1220
1230
1240
3500
2740
2300
2305
2355
2355
1265
2800
3300
2735
test
name
FUV focus sweeps
FUV HV variability
FUV HV variability
FUV HV variability
FUV dark count rate #1
Repeatability monitor #1
FUV timing threshold settings
FUV walk settings
FUV timing threshold settings
FUV walk settings
FUV dark count rate #2
FUV Accum Check
FUV cal ss flats S/N=30
FUV G130M sensitivity
FUV G160M sensitivity
FUV G140L sensitivity
FUV sensitivity with QE grid off
FUV OSM1 position checks
FUV dark count rate #3
FUV grating stability
FUV grating stability
NUV grating stability
NUV grating stability
G225M 2nd order sensitivity
FUV high local count rate
FUV BOA throughput & resloution
Geometrical Correction WCA part
day
completed
date
Thur
Thur
Thur
Thur
Thur
Fri
Fri
Fri
Fri
Fri
Fri
Sat
Sat
Sat
Sat
Sat
Sat
Sat
Sun
Sun
Sun
Sun
Sun
Sun
Sun
Sun
10/09/03
10/09/03
10/09/03
10/09/03
10/09/03
10/10/03
10/10/03
10/10/03
10/10/03
10/10/03
10/10/03
10/11/03
10/11/03
10/11/03
10/11/03
10/11/03
10/11/03
10/11/03
10/12/03
10/12/03
10/12/03
10/12/03
10/12/03
10/12/03
10/12/03
10/12/03
Test Program by D. Ebbets (Ball), E. Wilkinson (CU), and IDT.
1110
2750
1120
2741
850
3000
2306
2805
2735
1450
1460
1470
2730
2731
2306
850
1720
2100
2110
2120
850
1437
2740
2506
1730
2307
3700
3400
50
2307
50
1155
1156
FUV CDS Pt-Ne Group 1
FUV resolution, QE grid off
FUV CDS Pt-Ne Group 2
FUV dark count rate, QE grid off
Repeatability Monitor #2
FUV Cal SS flats, S/N = 100
G130M Grating Stability #1
FUV high local count rates G160M
Geom Corrections WCA
TA dispersed mode centroids
TA dispersed light phase 4
TA dispersed light phase 5
FUV geometric corrections PSA
Geom Corrections PSA 7x7 pinhole
G130M Grating Stability #2
Repeatability monitor #3
FUV flats aperture offset 2
FUV CO initial spectra
FUV scattered light
FUV high quality spectra
Repeatability monitor 4
NUV TA flooded aperture with Kr
FUV dark count rate 3
NUV flats with CDS D2 lamp
FUV flats aperture offset 3
FUV stability
NUV Efficiency Suplement
Side 2 Mechanism Verification
TA1 Focus Sweeps
NUV stability
TA1 Focus Sweeps
NUV G185M CDS Pt-Ne Spectra in N2
NUV G225M CDS Pt-Ne Spectra in N2
Mon
Mon
Mon
Mon
Mon
Mon
Mon
Mon
Tues
Tues
Tues
Tues
Wed
Wed
Wed
Wed
Wed
Wed
Thur
Thur
Thur
Thur
Thur
Thur
Fri
Fri
Sat
Sat
Mon
Mon
Tues
Tues
Wed
10/13/03
10/13/03
10/13/03
10/13/03
10/13/03
10/13/03
10/13/03
10/13/03
10/14/03
10/14/03
10/14/03
10/14/03
10/15/03
10/15/03
10/15/03
10/15/03
10/15/03
10/15/03
10/16/03
10/16/03
10/16/03
10/16/03
10/16/03
10/16/03
10/17/03
10/17/03
10/18/03
10/18/03
10/20/03
10/20/03
10/21/03
10/21/03
10/22/03
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FUV G130M Spectral Resolution
Segment A
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FUV G130M Spectral Resolution
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NUV G225M Spectral Resolution
30000
29000
28000
27000
lam2186
lam2217
lam2233
lam2250
lam2268
lam2283
lam2306
lam2325
lam2339
lam2357
lam2373
lam2390
lam2410
26000
25000
24000
23000
22000
21000
Requirement
20000
19000
18000
17000
2070
2170
2270
2370
2470
2570
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Spectral Resolution Summary
• FUV channel
– G130M & G160M
– G140L
R > 20,000
R > 2,000
• NUV channel
– G185M
– G225M & G285M
– G230L
R > 16,000
R > 20,000
R > 1,700 (over most of bandpass)
• Bright Object Aperture (BOA) resolution degraded
– Wedge in ND filter degrades resolution by factor of ~2.5 for FUV
modes and ~4 for NUV modes.
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FUV Sensitivity
Detector QE
Segment A
Detector QE
Segment B
This point falls outside the specified wavelength
range and thus does not violate requirements.
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NUV Flat Structure
B
A
COS G185M NUV P-flat
1.36% Poisson rms
1000
Intrinsic detector scatter
(1s=3.25%) within the
100x100 pixel box shown in
dashed lines
500
Pixel (dispersion)
Pixel (dispersion)
C
20,000 - 40,000
0
counts per pixel in
each stripe
500 Pixel (cross-dispersion) 1000
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NUV Flatfield S/N
Normalized
ratio of first
half of
exposure to
second half
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FUV & NUV Flat Fields
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NUV Spatial Resolution
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Optics Select Mechanism (OSM)
Optics Select Mechanism Two
• Full 360 Degree Rotation
• 101 arcsecond step size,
with selectable step rate (78
steps/sec baselined)
• Coarse and fine resolvers
provide position feedback
Ferris wheel mode
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OSM Stability with Time
Helicopter mode
(typical component test results)
1 resel
~ 4 minutes
G160M
G130M
G140L
NCM-1
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G130M Segment A – Helicopter Orientation
-0.906 Arcseconds of Drift
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G160M Segment A – Helicopter Orientation
G160M Seg A Image Motion in Helicopter Orientation
1
0.5
0
-01.069 Arcseconds of Drift
X-drift 1
X-drift 2
X-drift 3
X-drift 4
X-drift 5
X-drift 6
X-drift 7
X-drift 8
X-drift 9
X-drift 10
X-drift 11
X-drift 12
X-drift 13
Average
Motion (pixels)
-0.5
-1
-1.5
-2
-2.5
-3
-3.5
-4
0
500
1000
1500
2000
2500
3000
3500
4000
4500
Time (sec)
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G185M – Helicopter Orientation
-9.39 Arcseconds of Drift
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OSM Stability Summary
• The OSM met stability requirements in component level
testing (helicopter mode).
• Science calibration (Ferris wheel mode): OSM1 & OSM2 did
not meet requirements in some cases.
• Post science cal GN2 testing (helicopter mode) has shown
excessive drift in some test cases.
– OSM relaxation may be due to thermal effects. Bench is not thermally
controlled in helicopter mode.
• Ball conducting additional test to further characterize problem.
• COWG and COS FIG groups will consider operational
changes to mitigate the problem. COS IS evaluating science
impacts.
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COS Science Calibration Summary and Status
• Science calibration complete
– All instrument modes exercised.
– Instrument stimulated by continuum, emission line, and absorption line
(O2 and CO) sources.
• Performance is excellent
– Resolution, sensitivity, alignment, image quality, focus.
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•
•
Flight software performed as expected
OSM stability under investigation
Expect shipment to GSFC shortly
Functional tests every 3 months; NUV throughput tests every 6
months
• OPUS and CALCOS processed thermal vacuum test data in
MAST.
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