04 April 2002
AGENDA
1.
SMOV3B Update
2.
ACS Status
3.
NCS Status
4.
WFPC2 SMOV3B Results
Carl Biagetti
George Hartig
Larry Petro
Brad Whitmore
Next TIPS Meeting: 18 April 2002

As of 03Apr02

SMOV3B
SMOV3b PLAN
TIPS 04Apr02
Carl Biagetti
• MEASURE/MONITOR NEW SPACECRAFT BEHAVIOR
• POINTING, THERMAL, POWER
• RECOMMISSION EXISTING SIs
• STIS, WFPC2
• COMMISSION NEW SIs
• ACS
• Science/EROs in early April
• REVIVE NICMOS
• VIA NCS COOLDOWN
• Science/EROs in late April
Page 2

SMOV3B
TIPS 04Apr02
Carl Biagetti
ACS activated
• Temperature set point & CCD functional
STIS activated
• CCD functional, End-BEA Test, pre-NCS baseline tests, darks and biases
• All nominal
FGS
• Guiding functionality verified and pre-NCS baseline jitter tests
• All nominal
• BEA science
NCS
activated and
NICMOS
cooldown started (18 March)
• Late and slow
• FGS/FHST/STIS high voltages off during NICMOS cooldown
WFPC2
• in PROTECT DECON
Page 3

SMOV3B
TIPS 04Apr02
Carl Biagetti
ACS
Coarse/fine alignment completed 2 April - Nominal
EROs commenced 1 April
STIS
- Recommissioned
SMOV calibrations mostly complete
CCD science enabled and has resumed
MAMA science enabled but usage still restricted due to NICMOS cooldown
WFPC2
- Recommissioned
Cooldown & UV Monitoring began and continues - nominal
GO science enabled and has resumed
All other SMOV complete
NICMOS
Cooling down but 2 –3 weeks behind schedule
NICMOS intentionally safed on 28 March to facilitate cooldown
FGS
- Recommissioned
Guiding and astrometry
Page 4

SMOV3B
TIPS 04Apr02
Carl Biagetti
NICMOS
Cooldown is slower than expected (several weeks vs. 10-day predict)
End temperature is uncertain
NICMOS SMOV on hold until thermal behavior is stable
ACS
Achievement of fine alignment (2 Apr) occurred earlier than expected
• Allowed acceleration of EROs and GO/GTO science
Some calibrations have been moved earlier due to the small ACS/FGS alignment offsets => 3-week shortening of overall SMOV
ERO
• Visits 1-4 (UGC10214 & NGC4676) – pointing erroneously offset
• Visits 3 & 4 rescheduled for day 9 Apr => 1 week delay
• Visits 1 & 2 corrected with intercept SMS for 7 Apr => no delay
SBC (MAMA high-voltage) is restricted due to longer NICMOS cooldown
ACS/WFC Flat Field Stability (9018)
• TTRB approved the request for extra orbits for CR-splitting Page 5

SMOV3B
TIPS 04Apr02
Carl Biagetti
STIS
MAMA usage (high-voltage) is restricted due to longer NICMOS cooldown period
• Impacted SMOV End-BEA Test and delayed SMOV Contamination
Monitor
• Has delayed NUV/FUV science
• May be re-enabled in week of April 15
FGS
SMOV Jitter Test failed on 25 March
• Improperly specified target proper motion
Page 6

SMOV3B
TIPS 04Apr02
Carl Biagetti
UPDATED AS OF 3 APRIL
Release 09 March
NICMOS Cooldown 18 Mar - tbd
STIS Basic GO Science
WFPC2 Cooldown
22 March
22 March
WFPC2 GO Science
ACS ALIGN
ACS EROs
ACS Basic GO/GTO Science (CCD)
26 March
22 March – 2 April
01-09 April
11 April
(delayed with uncertain endpoint)
(MAMA science delayed)
(5 days ahead of plan)
(~ 1 week ahead of plan)
(on schedule)
NICMOS Filter Wheel Test
NICMOS Alignment (PAM adjust)
NICMOS EROs
NICMOS Basic GO Science
SMOV Complete
Mid-late April
TBD late April
TBD May
TBD May
TBD Aug
(~ 3 week delay)
(~ 3 week delay)
(~ 3 week delay)
(~ 3 week delay)
(without fine aperture locations)
(ACS/NIC coronographs enabled)
Page 7

George Hartig
4 April 2002
TIPS Meeting
• SMOV activities proceeding as expected since last report (TIPS) but proposals are being executed earlier than planned thanks to the already good pointing accuracy
• CCD daily monitoring prog. confirms the CCDs are performing well
– read-out noise remains stable for both cameras
– dark current rate well below nominal values (WFC = 7 e/p/hr, HRC=10 e/px/hr; Sirianni)
– fluctuation of bias level of amplifier WFC-B reported previously is confirmed and found also in ground-based data
• Frequency of cosmic ray hits analyzed and found to agree with predictions based on WFPC2 data (Riess)
• Optical alignment program successfully completed on 3 April
• First annealing procedure executed on 29 March
– Pre and post anneal data used to derive the growth (& decline!) of hot px
• First installment of ERO images obtained, under processing by IDT
Page 1

George Hartig
4 April 2002
TIPS Meeting
T i t l e
Science data buffer check
CCD functional
CCD daily monitoring
I D
9 0 0 3
9 0 0 5
8 9 4 7
ACS CCD hot pixel annealing 9 0 3 1
ACS corrector alignment, fine 9 0 1 4
ACS ERO programme
ACS to FGS alignment
8 9 9 2
9 0 1 1
CCD geometric distorsion
CCD preflash test
ACS CTE test
SMOV contamination plan
9 0 2 8
9 0 3 2
8 9 4 8
9 0 1 0
HRC coronograph repeatibility 9 0 1 6
ACS sensitivity 9 0 2 0
SBC anomalous recovery test 9 0 0 8
WFC flat field stability 9 0 1 8
HRC flat field stability 9 0 1 9
SBC dark current measurement9 0 2 2
SBC PSF measurement 9 0 2 3
SBC flat field uniformity
SBC geometric distorsion
9 0 2 4
9 0 2 7
ACS ramp filter test 9 0 2 6
ACS grism/prism performance 9 0 2 9
HRC coronograph acquisition 9 0 1 2
ACS pointing stability 9 0 1 7
Scattered light in coron. obs. 9 0 2 5
S t a r t l o c a l d a t e t i m e
11.3.
E n d d a t e l o c a l t i m e
P I S u p e r v i s o r
7:12 11.3. 22:38 S T S c I C o x
12.3.
13.3.
5:35 12.3. 16:56 S T S c I C o x
1:50 14.3.
8:26 S T S c I C o x
14.3. 10:01 15.3. 19:58 I D T Clampin
17.3. 20:04 end of SMOV
22.3. 10:40 29.3.
6:23
I D T Clampin
I D T H a r t i g
28.3.
9:47 30.3. 15:45 S T S c I C o x
28.3. 18:11 2.4. 19:57 I D T H a r t i g
31.3. 20:33 7.4. 13:05 I D T F o r d
3.4.
0:13
5.4. 16:09
3.4.
2:45
5.4. 23:31
I D T H a r t i g
I D T H a r t i g
5.4.
1:42 5.4. 15:52
8.4. <---> 15.4.
S098
I D T M e u r e r
S T S c I C o x
8.4. <---> 15.4.
8.4. <--->
8.4. <--->
8.4. <--->
15.4. <--->
15.4.
14.4.
15.4.
21.4.
S098 I D T Clampin
S098
S098
I D T T r a n
I D T Golimowsk
S098 S T S c I De Marchi
S105 I D T Kimble
15.4. <---> 21.4.
15.4. <---> 21.4.
15.4. <---> 21.4.
29.4. <--->
29.4. <--->
29.4. <--->
29.4. <--->
5.5.
5.5.
5.5.
5.5.
S105 I D T Kimble
S105 S T S c I Bohlin
S105 S T S c I Bohlin
S119 I D T Kimble
S119 I D T H a r t i g
6.5. <--->
6.5. <--->
6.5. <--->
2.6. <--->
2.6. <--->
12.5.
12.5.
12.5.
9.6.
9.6.
S119 S T S c I Bohlin
S119 I D T M e u r e r
S126
S126
I D T T s v e t a n o v
I D T T s v e t a n o v
I D T Golimowsk S126
S154
S154
I D T H a r t i g
I D T Golimowsk
Page 2

George Hartig
4 April 2002
TIPS Meeting
– Both WFC and HRC images noticeably comatic, but well in range of the corrector mechanism adjustability
– Aperture location correct to within ~2-3 arcsec
– Throughput approximately as expected
– Filters with BG-40 blockers (F435W, F475W, F502N, F555W) appear OK
– 3 iterations of observation/corrector adjustment 22-27 March
– Phase retrieval analysis used to derive req’d tip/tilt and focus corrections
– Realtime commands sent to effect adjustments
– Focus and tip/tilt mechanism scans performed 29,31 March
– Encircled energy, sharpness, width and phase retrieval analyses used to trim corrector alignment
– Realtime commands sent to effect adjustments Page 3

George Hartig
4 April 2002
TIPS Meeting
– Two iterations of prop 9574 (PI Gilliland) obtained simultaneous images with all three SI’s on 29 Mar, 2 Apr
– Phase retrieval analysis by J. Krist used to determine optimal focus settings
– Apr 2 data indicate WFC & HRC in excellent agreement with WFPC2
– Data under analysis by C. Cox
– Astrometric field observed with guide stars from same catalog
– Locations ~ 3 arcsec from pre-launch estimates; orientation v. close
– Scheduled for 5 Apr
Page 4

George Hartig
4 April 2002
TIPS Meeting
Page 5

George Hartig
4 April 2002
TIPS Meeting
• ACS image quality, following alignment activities, is excellent
– Both WFC and HRC handily exceed encircled energy CEI requirements (75% EE in .25 arcsec diameter at 633 nm)
– HRC easily exceeds EE goal of 80%; WFC close to goal
– Other image quality measures (PSF peak fraction, width) are as predicted
– Phase retrieval results indicate expected low level of residual aberrations (small amounts of field-dependent coma, astigmatism, defocus)
– WFC focal plane well-matched to image surface: focus variations over field are minor
Page 6

George Hartig
4 April 2002
TIPS Meeting
• ACS transitioned to ANNEAL mode on 29 March
– CCD temperatures rapidly rose from operating temps of –77 C
(WFC) and -80 C (HRC) as TECS were turned off and HRC window and ASCS interface plate heaters turned on
– Temperatures stabilized near expected levels: 19 C (WFC),
22 C (HRC)
• CCDs remained warm for ~24 h to permit annealing process
• Cooldown proceeded nominally with nominal operating temps achieved and TEC current stable in ~1.5 h on WFC
• Approximately 80% of hot pixels repaired; similar to STIS experience (Riess analysis)
Page 7

George Hartig
4 April 2002
TIPS Meeting
Annealing Temperatures
30
20
10
0
-10
13:00 14:00 15:00 16:00 17:00 18:00
UT
19:00 20:00 21:00 22:00 23:00
WFC
HRC
Page 8

George Hartig
4 April 2002
TIPS Meeting
Page 9

Larry Petro
April 4, 2002

❖
❖
❖
NICMOS continues to cool
➤
NICMOS is safed in order to accelerate cooling
NCC not surging, increasing cooling
➤
Occurred later than expected
NCS performance improvements under study
April 4, 2002
TIPS
2 / 10

❖
❖
❖
Turboalternator speed increased 100 rps (3/24)
➤
➤
Cause unknown
Improved cooling of NICMOS
NICMOS safed (3/28)
➤
Reduces heating in circulator loop by 0.1-0.2 W
NCC surging stopped (4/3)
➤
➤
Turboalternator inlet temperature 85 K (>90 K in ground tests)
Compressor speed limit (7090 rps) in effect until 80 K
April 4, 2002
TIPS
3 / 10

Actual NICMOS Cooldown, Compared to Model Prediction
280
260
240
220
200
180
160
140
120
100
80
60
8888 Detector
87007 Neon at N2 tank
MNPNCOLT (NICMOS Outlet Temp)
NDWTMP21 (Cold-Mask Temp, VCS front)
NDWTMP25 (VCS aft)
NFPA1TMP (Camera 1 FPA Temp)
MNPTAILT (TBA Inlet Temp)
0 1 2 3 4 5 6 7 8 9 10 11 12
Time since Compressor startup (Days since 2002 Day 78, 00:23.328 UT)
13
L. Bergeron
14 15 16
April 4, 2002
TIPS
4 / 10

NICMOS Inlet Temperature
110
105
100
95
90
85
80
75
7
135
130
125
120
115
MNRNCILT (NICMOS Inlet Temp)
MNPNCOLT (NICMOS Outlet Temp)
MNPLINTT (Comp/Circ Load Interface Temp)
8 9 10 11 12
Time since Compressor startup (Days since 2002 Day 78, 00:23.328 UT)
13
NFPA1TMP
NFPA2TMP
NFPA3TMP
14 15
L. Bergeron
16
April 4, 2002
TIPS
5 / 10

C. Long
April 4, 2002
TIPS
6 / 10

• Compressor
• Surging
400 rps
NCC Speeds & Temperature
No surging
8000
7000
6000
5000
4000
3000
2000
1000
0
0:00:00
April 4, 2002
80
Compressor
TBA
TBA inlet temperature
NICMOS inlet temperatur
2:24:00 4:48:00
78
7:12:00 9:36:00 12:00:00
Time Day 093 (hr:min:
TIPS
14:24:00 16:48:00
76
19:12:00
84
82
92
90
88
Turboalternator
Inlet Temperature = 85K
86
7 / 10

April 4, 2002
230
220
210
200
190
180
170
160
150
140
130
120
110
100
90
80
78 80 82
T= a(0) * exp( (x+a(1)) * a(2) ) + a(3) ["NICMOS OFF" range] fit range
TBA speed increase
MNPNCOLT (NICMOS Outlet Temp Data)
MNPNCOLT (NICMOS Outlet Temp Fit)
a(0)=139.83409
a(1)=-79.407515
a(2)=-0.16725383
MNPTAILT (TBA Inlet Temp Data)
MNPTAILT (TBA Inlet Temp Fit)
a(3)=96.473789
a(0)=103.60486
a(1)=-77.500066
a(2)=-0.10552370
a(3)=68.224042
No surging
NICMOS safed
84 86 88 90 92
2002 Daynumber
94 96 98 100 102 104
L. Bergeron
TIPS
100 K in
2   weeks without further improvements
8 / 10

❖
❖
❖
Lower NCC heat rejection interface temperature
➤
Lower CPL reservoir minimum temperature from -10   C to -12 C to -15 C
Increase NCC compressor speed
➤
➤
7300 rps present limit
7400 rps under consideration
Modify circulator loop
➤
Increase speed & pressure
April 4, 2002
TIPS
9 / 10

❖
❖
❖
NCS performing nominally
Cryovalve heater operating nominally
➤
No leakage past o-rings
AS pressure declined from 1.2
× 10 -6 to 0.7
× 10 -6 torr
Occasional 3 × spikes (< 2 × 10 -6 torr)
➤
Heater power cycle is nominal (40- 50 %)
60 - 70% occasionally
NICMOS cooling rate is slower than expected
April 4, 2002
TIPS
10 / 10

MEMORANDUM
TO: Distribution
DATE: April 4, 2002
SUBJECT: Questions and Answers from TIPS Meeting on 04 April 2002
SMOV3b Update
Presenter – Carl Biagetti
Q: What is the magnitude of the ACS/FGS alignment offset?
A: The ACS/FGS alignment offset is about 3 arc seconds.
ACS Status
Presenter – George Hartig
Q: Did the gravity release affect only the ACS optics and not the other components? Could the gravity release be part of the cause of the 3 arc seconds ACS/FGS alignment offset?
A: The gravity release would affect the whole system, and thus it can also contribute to the observed 3 arc second alignment offset.
Q: What are the values for the PSF peak fraction?
A: For the HRC, 86-87%. For the WFC, 80-81%.
Q: On the graph showing the encircled energy vs. radius, what do the solid line and dashed line represent?
A: The two lines are the same, except that the dashed line’s abscissa is stretched to bring out the details.
Q: The image distortions seen on plots, are those coma?
A: Those images have been corrected for coma effects. However, geometric corrections have not been applied to them, and thus the distortions.
Q: Can we apply what we have learned thus far from calibrating the ACS optics to WFC3?
A: The magnitude is too small for it to be of significance.
NCS Status
Presenter – Larry Petro
Q: Is the detector temperature expected to be slightly lower than the outlet temperature?
A: Yes, the detector temperature is expected to be between the inlet and outlet temperature, and in this case it is expected to be lower than the outlet temperature and above the inlet temperature.
Q: Are there other ways to reduce the head load?
A: Not at the moment. Once the system is stabilized, we will investigate other options. We will also be weighing the options against the amount of time they will take the telescope away from useful observing time.
1

Q: The heaters for the O-rings, can they be turned off or regulated so as to help with the cooling?
A: No, the heaters are needed for safety reasons.
Q: If the temperature of the detectors stabilized at 100K, what kind of science can we do?
A: We are currently looking into this.
Q: How is the attitude of the telescope affects cooling and how would that constrain observations?
A: When the Sun is at certain aspects relative to the telescope and when we have large Bright Earth exposure, these two situations can warm up the radiator. We will have to wait until the system stabilizes before we can separate out the various components.
Q: Any plans to correct the cooling model?
A: Yes, there is work in progress to correct the cooling model.
Q: Are the observed pressure spikes in the aft-shroud a concern for MAMA operations?
A: No, it should be fine.
WFPC2 SMOV3b Results
Presenter – Brad Whitmore
Q: How does the ripple compare to the read noise?
A: They are not measurable.
2