July 19, 2007
July 17, 2007 Wide Field Camera 3 Monthly Status Review
1

• WFC3 halfway through Thermal Vacuum Test #2
– Team is performing excellently and test is on schedule
– Several thermal issues discovered which will require modifications
– Internal calibration lamps have multiple problems
– Great progress on closing out liens from 2004 TV test
– Currently 39 days into the maximum 72 day T/V-2 test (SES chamber must be vacated and certified for the next HST test by 9/1/2007)
• Flight detector development
– Two outstanding IR flight detectors in packaging flow at Ball with installation of one into the instrument in Dec 2007
– Unresolved problem with the Thermal Electric Coolers (TEC) for the
UVIS CCD detectors
• Recovery plan in place but significant schedule concerns
2
July 17, 2007 Wide Field Camera 3 Monthly Status Review

-100
-50
0
50
Section A: Ambient Check
Section B: Bake Out
Orbital Hot Cycle
HO
CO
CQ
PS
CO
HQ HQ
HO
CS
CQ
Section D: Hot #1
Section F: Hot #2
Orbital Cycle: Cold
-150
-200
-7
Section C: Cold #1
0 7 14
July 17, 2007
Section E: Cold #2
21 28 35
Days
42 49
Wide Field Camera 3 Monthly Status Review
56
Thermal Balance
Radiator Environment Temp
63
HST Internal Environment
Temp
70 77 84
3

July 17, 2007
- Indicates Test Completed
Wide Field Camera 3 Monthly Status Review
4

• Verified operation of radiator heaters.
• Great progress in validating thermal model.
• Heat pipes all function as expected in 1g environment.
• Verified instrument cold start on both sides.
• Thermal performance of UVIS-2 has been stable and near nominal (compared with pre-anomaly UVIS-1).
• Achieved 145 
K on IR FPA in Hot and Cold environments.
• Throughput measurements show nominal optical performance.
• No SOFA errors (this issues appears to be resolved).
July 17, 2007 Wide Field Camera 3 Monthly Status Review
5

Preliminary analysis by Tom Brown
• UVIS-2 UV QE better than predicted; visible advantage vs. UVIS-1 inferred from ambient cal was an artifact of temperature and stray light
• Response of both CCDs comparable to UVIS-1 chip 1
• Optics throughput appears to have held up well since 2004 run
6
July 17, 2007 Wide Field Camera 3 Monthly Status Review

• Like UVIS-1, UVIS-2 demonstrates “goal” level read noise of 3 e rms, vs. spec of 4; very important in UV
• 5-10% noise penalty observed for the greater dynamic range of gain =
1.5 setting; will assess whether it is worthwhile to support both settings
Gain = 1 e /DN UVIS-2 (T/V #2) UVIS-1 (T/V #1)
Amp A 2.93
3.02 (ambient)
Amp B
Amp C
Amp D
Gain = 1.5 e /DN
2.89
2.92
3.05
2.97 (ambient)
2.86 (ambient)
2.99 (ambient)
Amp A
Amp B
Amp C
Amp D
July 17, 2007
3.12
2.99
3.05
3.20
3.21
3.25
3.22
3.36
Wide Field Camera 3 Monthly Status Review
Dark is <1 e/pix/hr at -79C
Preliminary T/V 2 analysis by Sylvia
Baggett
7

IR Throughput vs. Predictions
1.20
1.15
1.10
1.05
1.00
This is the run with the best controlled background.
Earlier runs came out even higher (good), but with wider spread than we have explained (puzzling)
– still investigating.
0.95
0.90
0.85
0.80
800 1000 1200 1400 1600 1800
Preliminary analysis by Tom Brown
Wavelength (nm)
•
No sign of the 10-15% deficit vs. component predictions seen in T/V 1
•
Indicates protected-silver mirror coatings are healthy
8
July 17, 2007 Wide Field Camera 3 Monthly Status Review

• RMS noise is in good agreement with previous results
• Must carefully assess whether there is any significant correlated noise
(some intermittent fixed pattern noise has been seen – perhaps 0.2-0.3 DN)
Noise
(e- rms)
DCL
Ball
Acceptance
Test
T/V 2
Quad 1 23.1
22.6
23.0
Preliminary T/V 2 analysis by Bryan
Hilbert
Quad 2 19.3
18.6
19.3
Quad 3
Quad 4
July 17, 2007
20.0
19.1
19.8
23.8
22.2
Wide Field Camera 3 Monthly Status Review
23.4
9

• Negligible drifts in response to orbital cycling in cold environment
•
Note that cold cycling case is more benign than hot cycling (not yet tested)
Image Position vs. Time Thru 6 Cold Orbital Cycles
July 17, 2007 Wide Field Camera 3 Monthly Status Review
10

• Spec is <10 mas in 200 minutes for UVIS; <20 mas for IR
• Cold environment again is likely more benign than hot environment equivalent
Image Position vs. Time Thru Slew in Cold Environment
July 17, 2007 Wide Field Camera 3 Monthly Status Review
11

July 17, 2007
• Meets spec in IR
• UVIS is ~20mas over 3 hours (spec is 10mas)
• Watching long term drift –
Realism of the test conditions not yet understood
• Plot by S. Baggett
& D. Karakla
12
Wide Field Camera 3 Monthly Status Review

• Grisms are properly oriented (0.6° and <0.5° off vs. ~2° tolerance and previous 82° error – well done team!
• Cross-dispersion profile of continuum spectra and monochromatic images shows good
FWHM – properly focused
• High thermal background seen in T/V
1 with previous G141 grism is now gone with added red blocking
G102 Continuum Spectrum
• IR thermal backgrounds thru filters in general are in good agreement with
Massimo Robberto model – project to nominal performance in HST OTA environment
July 17, 2007
G141 Continuum Spectrum
Analysis by Howard Bushouse
Wide Field Camera 3 Monthly Status Review
13

Hardware Issues with Science Impacts
• IR 6-stage control
– Out-of-spec control stability is problematic for a high dark-rate device such as
FPA129, given the strong dependence of dark rate on temperature
– Even for a lower dark rate part, there will be a transient trapping-release response to temperature changes (seen in T/V #1 with FPA64)
– The substantial calibration offset, combined with the limited temperature margins in the subsystem test, have made the team reluctant to push the FPA temperature as far as the thermal performance would permit – would be good to establish more margin in IR-3, IR-4 tests, in addition to resolving the calibration offsets
• Internal calibration system
– Internal flat-field calibration, on the ground and in space is crucial for the very rich filter set of WFC3
– Especially in UV, where no suitable diffuse, uniform sources exist in the sky
– Late turn-on of D2 (up to few minutes) is tractable, but failure to turn on would be a significant issue (there is only a single D2 lamp – no redundancy)
– The tungsten bulbs are required for a thorough ground cal with each potential flight detector, and then in orbit as well to track launch shifts or changes with time
14
July 17, 2007 Wide Field Camera 3 Monthly Status Review

2007
Jan
• Bar chart
Apr May Jun Jul Aug Sep Oct Nov Dec
2008
Jan Feb Mar
Comp. build
Rec FPA
2/16/07
Build Package
Component Build
Rec FPA
4/2/07
Troubleshoot
Build Package
Acceptance Test
Deliver
10/16/07
IR3
Acceptance Test
Deliver
12/2/07
IR4
Rebuild
Component Build
Acceptance Test
Deliver
11/15/07
Build Package
Rec CCD
Assembly
8/22/07
UVIS1
Acceptance Test
Deliver
1/26/08
UVIS3
July 17, 2007 Wide Field Camera 3 Monthly Status Review
15

• Two UVIS detector concerns
– Short due to conductive particle on flex lead
– TEC damage
• UVIS1-prime is being reassembled after thermal anomaly occurred during acceptance testing
• UVIS2 was delivered to GSFC on March 24, installed into WFC3, and is under instrument test
– probably has same TEC problems as UVIS1
• UVIS3 effort at BATC has started
– CCD Flex/Carrier assemblies (short resistant)
– Significant schedule challenges
July 17, 2007 Wide Field Camera 3 Monthly Status Review
16

• Wrapping up the anomaly investigation
– Conclusion: Anomaly was most likely caused by TEC column failure due to thermally-induced stresses caused by CCD anneal, and may have been aggravated by subsequent vibration testing
– TEC failure has not been duplicated on test units thus far. However, strength varies among devices, and we appear to have selected fairly weak TECs for UVIS1 and possibly UVIS2.
• The problem will be resolved on three fronts
– Reduce stresses on TEC to the extent possible
• ‘Ramp’ TEC power levels during ground test and on-orbit operation
– Strengthen future TECs to the extent possible (UVIS3 only)
• Use thermally-applied nickel (TAN) plating on TE columns to increase strength of solder joint
– Inspect the TECs more thoroughly using standardized criteria
• Identify flaws that could weaken TEC
17
July 17, 2007 Wide Field Camera 3 Monthly Status Review

•
ACS Qual Unit #4 instrumented and used to measure temperatures at each
TEC stage during operation
– Cooldown: Current increased rapidly from 0 
4.2 Amps
– Warmup: Current decreased rapidly from 4.2 
0 amps
– Anneal:
• ‘GSFC’ process: TEC allowed to warm for 1 hour before 1.0 amps applied rapidly
• ‘Ball’ process: 0.6 amps applied rapidly without a warmup period
C5 Ceramic
Wide Field Camera 3 Monthly Status Review
C1 Ceramic
18
July 17, 2007

Flex Cable
Procurement
Ball Procurement
GSFC Procurement
Connector & Carrier
Assembly
Detector Backside
Processing
CCD Assembly
Ball Task e2v Task
GSFC Task
July 17, 2007 e2v Packaging of Devices
Onto Existing Chip Carrier
Assemblies
Task in progress
Task complete
DCL Testing
Wide Field Camera 3 Monthly Status Review
UVIS3 Assembly
Delivery to
GSFC
19

Detectors previously delivered to the DCL
Read Noise (A)
(B)
Dark Current
Units e
e
e
-
/pix/hr
@-83C
CTE Serial (A)
Serial (B)
Parallel
QE @250nm
@500nm
@900nm
Full Well
%
%
% ke
-
Spec
3
3
20
UVIS Build #1
#018
<2.7
<2.7
0.43
#178
2.2
2.3
<5
UVIS Build #2
#040
2.1
2.2
0.13
#050
2.1
2.2
0.1
#136
2.3
2.6
#048
2.4
2.4
0.37
#044
2.4
2.5
0.38
0.999995
0.999997
0.999999
0.999999
0.999997
0.999999
0.999999
0.999997
0.999995
0.999996
0.999999
0.999999
0.999999
0.999999
0.999998
0.999997
0.999995
0.999999
0.999999
0.999999
0.999999
0.999999
0.999999
0.999999
40 59 51 51 41 55 36 45
60
23
50
68
27
92
66
27
85
63
31
99
62
32
99
69
35
70
65
31
102
63
32
92
CCD044 was delivered to the DCL June 20, 2007
20
July 17, 2007 Wide Field Camera 3 Monthly Status Review

100
90
80
70
60
50
40
30
20
10
0
200
July 17, 2007
IR4
IR3
IR1
IR2
400 600
FPA 64
IR Channel Wavelength Range
1400 800 1000 1200
Wavelength (nm)
FPA 129 FPA 150 FPA 165
1600
Wide Field Camera 3 Monthly Status Review
1800
21

100
90
80
30
20
10
0
70
60
50
40
0
July 17, 2007
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Dark Current (e
-
/sec/pix)
FPA 64 FPA 129 FPA 150 FPA 165
Wide Field Camera 3 Monthly Status Review
22
1

DOWNSTREAM lead pinched under foot of thermal shield
July 17, 2007 Wide Field Camera 3 Monthly Status Review
UPSTREAM Section of leads validated by Franka, 4/07
23

3/24 – 3/25/07
UVIS2 Detector
Installation
5/23/06 – 5/16/07
Build Flight IR1
Detector assembly
10/1/06 – 10/16/07
Build Flight IR3
Det. Assembly
10/1/06 – 12/3/07
Build Flight IR4
Det. Assembly
3/2/07 – 6/07
UVIS1 Detector
Reassembly and
Test
4/1/07 – 2/29/08
Build Flight
UVIS3 Det.
Assembly
July 17, 2007
9/08 Shuttle Launch
10/24/05 – 4/5/07
Instrument
Integration
4/5/07 – 8/31/07
Pre-IR Detector
Instrument
Level Testing
(Includes T/V test-2)
4/17/07– 8/26/07
T/V test #2
(Dedicated SES chamber time)
= NEW
= CRITICAL
PATH ITEM
8/31/07
Delivery to
HST I&T
12/3/07
Detector
Selection
NET 3/3/08 – 3/14/08
UVIS3
Installation?
12/3 – 12/14/07
Flight detector installation(s) and final instrument closeout
Wide Field Camera 3 Monthly Status Review
12/14 – 12/19/07
Acoustic -2
12/20 – 12/31/07
EMI / EMC -2
1/2/08 – 02/28/08
T/V test -3
12/3/07 – 2/28/08
T/V test -3
(Dedicated SES chamber time)
2/28/08
Final
Delivery to
HST I&T
24