Telescope and Instrument Performance
Summary (TIPS)
21 March 2002
AGENDA
1.
2.
3.
4.
5.
6.
Hubble Division Perspective
SM3B/SMOV3B Update
ACS Update
NCS/NICMOS Update
STIS Update
FGS/Pointing Update
Rodger Doxsey
Carl Biagetti
Guido de Marchi
Larry Petro
Paul Goudfrooij
Ed Nelan
Next TIPS Meeting: 4 April 2002
TIPS 21Mar02
Carl Biagetti/NISD
SMOV3B
SMOV3B
PROGRESS
As of 20 March
SMOV3B
TIPS 21Mar02
Carl Biagetti
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Page 2
SMOV3B
TIPS 21Mar02
Carl Biagetti
SMOV3b PLAN
• 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 mid/late April
Page 3
TIPS 21Mar02
Carl Biagetti
SMOV3B
SMOV3b PLAN THROUGH MARCH
Mar 3, '02
F
Task Name
S
S
M
T
W
Mar 10, '02
T
F
S
S
M
T
W
Mar 17, '02
T
F
S
S
M
T
W
Mar 24, '02
T
F
S
S
M
T
W
M
T
F
S
3/27
WFPC2 SCIENCE ENABLE
SM3B MISSION
BRIGHT EARTH AVOIDANCE (BEA)
HST RELEASE
3/9
HST RELEASE
3/9
(PCS1) FHST FOV TEST
STIS NOISE TEST (POST-BASELINE)
(PCS2) GYRO BIAS DETERMINATION
(PCS3) ATTITUDE INITIALIZATION
(PCS4) FHST/FHST ALIGNMENT
9002 ACS02 - ACS LOAD & DUMP ON-BOARD
8949 (WFPC2/1) WFPC2 PROTECT DECON
8957 STIS01 STIS CCD FUNCTIONAL
8994 (FGS01) GUIDE STAR ACQ (FGS 1&3)
8999 (FGS06) PRE-NCS JITTER TEST
9003 ACS03 - ACS SCIENCE DATA BUFFER C
9006 ACS06 - ACS CCD TEMP SET POINT DE
8958 STIS02A
8959 STIS03
PRE-NCS IMAGE QUALITY
STIS MAMA DARK vs. TEMP
8963 STIS 7 CCD BIAS IMAGES
8964 STIS08 CCD DARKS
8968 (PCS08) VEH DISTURB TEST (ACS FW &
9005 ACS05 - ACS CCD FUNCTIONAL
8961 STIS05 FIRST END-BEA TEST
8960 STIS04A
PRE-NCS JITTER TEST
FGS/FHST HV OFF
NCS FILL PROCEDURE
8967V1 NCS01 START NCS CPL
STIS MAMA HV RESTRICTION
8967 NCS01 NCS ACTIVATION & NICMOS COO
8968 VDT visits 31-33
8947 ACS05 ACS DAILY TEST
8961 STIS05
SECOND END-BEA TEST
8945 NCIMOS10 - NICMOS TEMP STABILITY
8958 STIS02B
POST-NCS IMAGE QUAL CHK
3/22
BEA COMPLETE
8968 VEHICLE DIST'B'CE TEST
(+V3)
8968 VEHICLE DIST'B'CE TEST (-V1)
3/22
3/22
9013 ACS13 - ACS COARSE ALIGNMENT
STIS CCD SCIENCE ENABLE
3/22
8950 (WFPC2/2) WFPC2 UVMON, COOL-DOWN
8952 (WFPC2/5) WFPC2 FLAT FIELD CALIBRA
8951 (WFPC2/4) WFPC2 LYMAN ALPHA CHEC
NICMOS "HOT" ATTITUDE
8960 STIS04B POST-NCS JITTER TEST
8944 NICMOS01 FW TESTS 1-7
Page 4
S
SMOV3B
TIPS 21Mar02
Carl Biagetti
SMOV - so far
BEA completes today
ACS – on schedule and nominal
STIS – on schedule & nominal
2nd end bea test removed
WFPC2 – on schedule & nominal (in PROTECT DECON)
23MAR - Cooldown and UV monitor to begin
NICMOS – Nominal
Cooling down
NCS fails first two start-up attempts => 2 day delay
Cooldown rate is uncertain as of (20mar)
FGS – Nominal
BEA science
Page 5
TIPS 21Mar02
Carl Biagetti
SMOV3B
MAJOR SMOV MILESTONES
(UPDATED AS OF 20 MARCH)
Release
NICMOS Cooldown
09 March
18-27 (tbd) March
(NOMINAL 10-DAY COOLDOWN)
STIS Basic GO Science
22 March
(No MAMA during initial NICMOS
cooldown)
WFPC2 Cooldown
22 March
WFPC2 GO Science
26 March
ACS ALIGN
22 March – 7 April
ACS EROs
08-11 April
“
“
“
ACS Basic GO Science (CCD)
11 April
“
“
“
NICMOS Filter Wheel Test
28 March – 04 April
NICMOS Alignment (PAM adjust)
05 April – 12 April
“
“
“
NICMOS EROs
20-24 April
“
“
“
NICMOS Basic GO Science
20 April
(without fine aperture locations)
SMOV Complete
27 July
(ACS/NIC coronographs enabled)
(may be accelerated 2-3 days)
(may be delayed ~ 1 week)
Page 6
Installation of the ACS
Guido De Marchi - ESA/STScI - ACS Group
•
The ACS was installed on board the HST on the 6th of
March replacing the ageing FOC
•
No problems encountered by astronauts during
installation
•
Aliveness test proved that the camera can boot
properly
•
Functional test run soon after to verify ability to
provide science grade data
Guido De Marchi – TIPS meeting – 21.3.2002
ACS functional test
•
After switch on, both CCD cooled rapidly to -67 C
•
Both filter wheels moved properly to position
•
A set of bias and dark frames was taken for both CCD
with several combinations of amplifiers and lamps
•
The ACS IDT and ACS group at STScI analysed the
data simultaneously but independently: same results!
Guido De Marchi – TIPS meeting – 21.3.2002
ACS functional test: bias frames
•
Read noise found to be at nominal values:
WFC: ~5 e- rms; HRC: ~4 e- rms
•
Fourier analysis reveals no correlated noise
•
Large number of cosmic ray hits seen in bias frames,
non uniformly distributed (gradient). Reason: long
read out time! One might benefit from CR-SPLIT for
exposures shorter than a few minutes [Sirianni]
•
Cosmic ray events show no tails (i.e. no deferred
charge) thus proving good CTE [Riess]
Guido De Marchi – TIPS meeting – 21.3.2002
ACS functional test: flat frames
•
No cosmetic degradation apparent (WFC, HRC), no new
large dust particles nor shifting of existing ones [Riess]
•
Illumination levels consistently higher (~20%) than on the
ground for all lamps. Could be due to higher operating
temperature in vacuum. Planned internal flat fields will
need shorter exposure times [Hartig]
•
Shadow cast by coronographic finger suggests a shift
occurred during flight. Similar shifts seen when moving
the camera on the ground [Hartig]
•
Cycle HRC/SBC fold mirror to ensure nominal position
Guido De Marchi – TIPS meeting – 21.3.2002
ACS SMOV programme
•
On-board memory tested for bit flips during SAA passages: only 8 bits flipped in 6x34 million bytes [De Marchi]
•
Both CCD (WFC, HRC) cooled rapidly to operating temperatures and remain stable there (–77 C, –80 C) [Cox]
•
GSFC/Ball are reviewing the thermal models for opportunity to further lower operating temperatures
•
Dark rate stable to within +/-1 at ~7.5 e-/px/hr, well below
specifications (< 25 e-/px/hr) [Sirianni, Mutchler, Cox]
Guido De Marchi – TIPS meeting – 21.3.2002
ACS SMOV programme: WFC bias
•
After CCD activation, bias level gracefully decays and
stabilises at ~20 e- down after a few hours [Pavlovsky]
•
Level of WFC amplifier B shows larger scatter, with
variations of up to ~ +/- 10 e-, but RN still 5 e- [Sirianni]
•
This is not a problem because the offset (i.e. the difference between the bias level in the image and in the physical overscan) is constant to within +/- 0.3 e- [Sirianni]
•
Correct bias level can be determined from overscan
Guido De Marchi – TIPS meeting – 21.3.2002
NICMOS
Cooling System Status
Larry Petro
March 21, 2002
Summary
❖
Successfully installed during
SM3b (3/7 & 8)
❖
NCS is operating nominally
❖
Startup anomalies encountered
❖
NICMOS cooldown and NCS
performance monitoring
underway
March 21, 2002
TIPS
2/8
Commissioning activities
❖
NCC circulator loop neon fill (3/16 05:03)
❖
CPL startup begun (3/16 07:53)
❖
NCC circulator started (3/16 23:13)
❖
NCC compressor & turboalternator started
(3/17 00:12)
➤
NCC safed (3/17 07:25)
❖
Restart of NCC failed (3/18 18:16)
❖
Successful start following warmup (3/19 00:23)
March 21, 2002
TIPS
3/8
Turboalternator anomalies
March 17, 2002
~10% speed
reductions
TA lowspeed
safemode entry
N. Jedrich
March 21, 2002
TIPS
4/8
Restarts 3/18 & 3/19
B. Fafaul
3000
❖
2500
2000
(67)MNCOIFRQ
(69)MNCORSPD
❖
(71)MNTBASPD
1500
(74)MNTBALDI
(54)MNTBAIPR
(53)MNCOINPR
(72)MNCOINOI
1000
Similar failures in
ground test
Retry is standard
procedure
B. Fafaul
500
3000
0
150
160
170
180
190
Compressor starts, but
turboalternator fails to spin
200
2500
2000
(67)MNCOIFRQ
(69)MNCORSPD
(71)MNTBASPD
1500
(74)MNTBALDI
(54)MNTBAIPR
(53)MNCOINPR
(72)MNCOINOI
1000
500
Both turbines start
0
150
March 21, 2002
TIPS
160
170
180
190
200
5/8
NCS cooldown
❖
❖
❖
❖
Rate ~1/2 expected in first
60 hr
Turboalternator inlet now
139 K vs 84 K expected
Cooling at 9 K/day
End surging in 5 more days
at this rate at this rate
L. Bergeron
March 21, 2002
TIPS
6/8
NICMOS cooldown
❖
❖
❖
❖
NICMOS outlet
187 K vs 125 K
expected after 60 hr
Cooling at 16 K/day
7 days to reach
operating
temperature at this
rate
Detectors ~190 K
L. Bergeron
March 21, 2002
TIPS
7/8
NCS Status
❖
Cryovalve heater operating nominally
➤
➤
➤
❖
❖
No leakage past o-rings
No change in Aft Shroud pressure during NCS
operation (holding at ~1×10-6 torr)
Heater power cycle is nominal (40- 50 %)
Jitter during surging less than 7 mas
Cooling rate less than anticipated during first
60 hours of cooldown
➤
March 21, 2002
Approaching expected rate
TIPS
8/8
STIS Status:
Results from SM3B/SMOV3B
Paul Goudfrooij & Jeff Valenti
Mar 21, 2001
TIPS
STIS (In-Bay) Noise Tests
Purpose:
Monitor shuttle noise environment; support ACS noise tests
Test Sequence:
8 pairs of CCD bias frames (all 4 amps, unbinned and binned 2x2)
MAMA electronics noise test with high voltage off, lowered threshold
Measurements before and after HST capture and after HST release
Results:
Read Noise (electrons)
Amp Gain Binning Test 1 Test 2 SMOV Nominal
D
1
None
5.8
5.6
5.5
5.2-5.9
D
1
2x2
4.8
5.0
5.0
4.6-5.3
(Side-2 pattern noise (15-18 kHz) contributes 1.2 electrons to read noise)
SMOV3B Activity Flow for STIS
Mar 13
Before
SMOV3B
CCD
Biases
During
SMOV3B
New Flux
Standards
Daily
CCD
Functional
Image
Quality
Image
Quality
Mar 12
Mar 14
NCC
On
Mar 24
Mar 16-18
Jitter
Test
MAMA Dark
vs. Temp
Mar 13
Jitter
Test
No
Yes
Begin
CCD
Science
Mar 29
MAMA
Mar 28
Mar 15
MAMA
Darks
Mar 22
Mar 14
(only 1)
Contingency
Plan
OK?
Jitter
Test
End of
BEA Test
After
SMOV3B
CCD
Darks
Mar 13
CCD
Daily
OK?
No
Mar 29
Leave
Yes BEA
Contamination
Monitor
(6) Weekly
Mar 31
Begin
MAMA
Science
2/Week
Mar 29
End-of-BEA (Bright Earth Avoidance) Test
Purpose:
Test for contamination that might cause polymerization if illuminated by
solar UV radiation, thereby significantly affecting FUV throughput.
Test Sequence:
G140L spectra of WD2126+734 before and after SM3B (∆t = 0.55 yr)
Results:
Fractional
Change (%)
Calculate fractional change in net count rate vs. wavelength
No Significant
Contamination
Change after Time & Temp Correction
Raw Change in Count Rate
Wavelength (Å)
Fractional change in sensitivity is –0.3 ± 0.8%
MAMA Dark Rate vs. Temperature
Purpose:
Verify nominal performance of MAMA detectors
Test Sequence:
Measure MAMA dark rate at beginning and end of two SAA-free periods
Results:
FUV-MAMA
Side 1
Side 2
SMOV
MAMA Dark
Rate Nominal
NUV-MAMA
Image Quality Test
Purpose:
Check STIS focus before and after NCC turn-on
Results:
Phase retrieval by
John Krist
–2.1 µm defocus after
breathing correction
Within realm of breathing
model accuracy
Pre-NCC turn-on
Focus is Nominal
MEMORANDUM
TO:
Distribution
DATE:
March 21, 2002
SUBJECT:
Questions and Answers from 21 March 2002 TIPS Meeting
HD Perspective
Presenter – Rodger Doxsey
No questions.
SM3b/SMOV3b Update
Presenter – Carl Biagetti
Q: Would the NICMOS cool-down schedule slip affect the ERO release plan?
A: Yes. The original plan was to have a single press release together with ACS, but now we might have to
delay the release of ACS results or have 2 separate press releases. The decision will be made tomorrow.
ACS Update
Presenter – Guido De Marchi
Q: What is the timescale for the ACS/WFC Amplifier B Bias level decay?
A: The timescale is about 24 hours.
Q: When investigating the possibility of achieving a lower temperature for ACS, will the engineers also
look at the implications to the entire system and how it will affect the aft shroud temperature?
A: Yes, the engineers will look into how the entire system will be impacted by a change in the operating
temperature for ACS.
Q: What is the turnaround time for the data to get to us?
A: The data takes a few hours to get to the ground and about 40 minutes to go through OPUS.
Q: When will the ACS GTO program start?
A: The bulk of the program will begin when ACS is properly aligned with FGS, possibly by mid April.
Basic science observations, however, will start a bit before then.
NICMOS/NCS Update
Presenter – Larry Petro
Q: Is the gradual speed decline of the turbo alternator anticipated?
A: The speed decline is anticipated since the fluid density increases with decreasing temperature. This is
normal.
1
Q: The actual and the model cool-down rates were plotted against time. Would a plot of the cool-down
rates versus temperature provide better comparisons?
A: We have not done that comparison yet, and it will be next.
Q: Could the slower than expected cool-down rate simply mean that the cool-down model used was
wrong?
A: We may have more parasitic heat loss in the system.
Q: Given the longer than expected cool-down rate, does it mean that NICMOS and the entire system have
to be on all the time?
A: The current plan is to keep NICMOS cool at all times.
Q: What is the warmest temperature that NICMOS can operate at?
A: At this point we do not have detailed calculations yet, but the cooler (around 82 – 83 K) the better. The
team will need to establish not the temperature requirements but the critical requirements for scientific
performance at operational temperature above our current expectation.
Q: Can we manually speed up the cooling process?
A: The cooling system is at maximum performance right now, and there is nothing we can do to speed up
the cooling process at this point.
STIS Update
Presenter – Paul Goudfrooij
Q: What is the current temperature range for the MAMAs?
A: It is not clear at this point. From looking at the dark frames, the temperature seems to be the same as
before the servicing mission. We will need to wait for a few weeks, until all other systems are up, before
we can get a better read on the MAMA temperatures.
FGS/Pointing Update
Presenter – Ed Nelan
Comment: The small-amplitude periodic jitters could be due to the new solar arrays or they could be from
heating and cooling from the other parts of the spacecraft.
2