Instrument Science Report NICMOS 2003-008
NICMOS Temperature Table
A.B. Schultz, J. Schultz, M. Robinson, and E. Roberts
August 29, 2003
ABSTRACT
Nine NICMOS Cooling System (NCS) mnemonics and five temperature sensors are
extracted from the engineering telemetry and bundled together into an STSDAS FITS
table, the NICMOS Temperature Table. The FITS binary table has the same ipppssoot as
the corresponding science observation with a file name extension of “epc”. The table is
created by the Engineering Data Processing System (EDPS) and can be retrieved with the
science data from the HST Archive for which OTFR has been requested. The table is provided as an aid for use in calibration, temperature monitoring, and as a convenience to
science data users.The table will be available following installation OPUS 14.4.
Introduction
The Near Infrared and Multi-Object Spectrometer (NICMOS) was installed on HST during the Second Servicing Mission (SM2) in February 1997. Due to a thermal short,
following launch, the solid cryogen sublimated faster than expected reducing the lifetime
from the anticipated 60 months to 22 months. Subsequently, NICMOS warmed up to temperatures around 260 K and was not available for science observations for 3 years. The
NICMOS Cooling System (NCS) was installed on the Hubble Space Telescope (HST)
during the HST Servicing Mission 3B (SM3B) in March 2002. After a lengthy cool down
period during which NICMOS was shut off to expedite the cool down, the NICMOS
detectors now operate at a temperature of 77.1 K +/- 0.05 K, about 15 K warmer than during Cycle 7 & 7N.
The NICMOS enclosure is about the size of a phone booth and replaced the Faint
Object Spectrograph (FOS) in the HST aft shroud. It is an axial instrument on the side of
HST facing away from the Sun, on the shadow side of HST in the +V2,-V3 quadrant. On
Copyright© 1999 The Association of Universities for Research in Astronomy, Inc. All Rights Reserved.
Instrument Science Report NICMOS 2003-008
the sky, the NIC2 aperture pickoff is ~460 arcsec (~13 cm) from the HST optical axis (V1axis). Figure 1 is an overview schematic of HST showing the instrument bay relative to the
aperture door.
The NICMOS detectors are NICMOS3-type 256 x 256 pixel HgCdTe detectors manufactured by Rockwell. The performance of these detectors is sensitive to the operating
temperature and to temperature stability. Results from the early NICMOS Servicing Mission Orbital Verification (SMOV) calibration program following SM3B indicates that the
NICMOS cameras and detectors are operating quite well and within expectations (Boeker
et al. 2002, 2003; Schultz et al. 2002; Schultz et al. 2003).
Hardware and Cooldown
The NCS hardware consist of the NICMOS Cryogenic Cooler (NCC), a Capillary
Pumped Loop (CPL)/Radiator assembly, an Electronics Support Module (ESM), and an
associated interface harness. Figure 2 presents a diagram of the NCS showing the major
components and subsystems as installed on HST. Cooling is provided by neon gas circulating through the cooling coils at the aft end of the NICMOS dewar.
The NCC was started for the first time on March 17, 2002 (day 2002.078). During the
first 17 days of the cooldown, the compressor was operated at a rate of 7100 rps to protect
the software compressor speed limit of 7300 rps. The compressor “surged” above and
below the commanded speed until the turboalternator inlet temperature fell below ~82 K.
Surging stopped 17 days into the cooldown and the commanded compressor speed was
raised to 7300 rps. The NICMOS main electronics boxes (MEBs) were shut down to minimize parasitic heat leaks and to increase the cooldown rate. The temperature sensors in
the dewar were unavailable and dewar cooldown was not monitored. The temperature setpoint was reached and the NCC started regulating the compressor speed to keep the average temperature at 70 K. The MEBs were turned on. A series of temperature set-point tests
were performed. A control set-point temperature of 72.4 K was chosen for the first year of
operation, yielding a detector temperature of 77.1 K (Jedrich et al. 2003).
Temperature Sensors
A set of 14 mnemonics (sensors) were selected to be included in the temperature table
(Swain 2000). The 14 mnemonics are listed in Table 1. The mnemonic values are
extracted from the engineering telemetry and written into the temperature table by the
Engineering Data Processing System (EDPS), formally known as the Observatory Monitoring System (OMS). The new NICMOS temperature FITS engineering data table has a
file name extension of “epc” and is archived with an ipppssoot corresponding to the science data ipppssoot. The time range of the table is over the duration of the corresponding
exposure. Engineering data receipt typically trails science data receipt by 1-2 days. For
archival retrievals that occur after this FITS binary table has been archived, and for which
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Instrument Science Report NICMOS 2003-008
OTFR has been requested, the FITS binary table will automatically be retrieved with the
science data set.
Table 1. NICMOS and NCS telemetry mnemonics.
Mnemonic
MSID
Sample
time
Units
Operational
limitsa
Description
MNCIRSPD
M25L563A
60s
rps
0 - 1250
NCS CIrc Rot SPeeD
MNCORSPD
M25L565A
15s
rps
0 - 7360
NCS COmp Rot SPeeD
MNCONTRL
M32J991A
60s
K
? - 103.344
NCS CONTRL point temp
MNPDSTPT
M32J993A
60s
K
77.1
NCS PiD SeT PoinTemp
MNCRADAT
M26T780A
60s
C
-70 - +70
NCS Cpl RAD A Temp
MNHTREJT
M25T788A
60s
C
-45 - +45
NCS HeaT REJect Temp
MNPNCOLT
M25T551A
60s
K
? - 197.102
NCS Pri NiC OtLt Temp
MNRNCILT
M25T548A
60s
K
? - 103.310
NCS Red NiC InL Temp
MNRNCOLT
M25T547A
60s
K
? - 103.420
NCS Red NiC OtLt Temp
NDWTMP11
N12T656A
30s
K
? - 77.43
Camera 1 Mounting Cup temp
NDWTMP13
N12T658A
30s
K
? - 76.28
Camera 3 Mounting Cup temp
NDWTMP14
N12T659a
30s
K
? - 76.81
Cold Well temp
NDWTMP21
N12T662A
30s
K
48.15 263.15
Camera 2 Cold Mask temp
NDWTMP22
N12T663A
30s
K
48.15 263.15
Camera 3 Cold Mask temp
a. Operational limits are a range of values over which the sensor will operate normally.
MNCIRSPD - NCS CIrc Rot SPeeD
A miniature centrifugal circulator pumps cryogenic neon in the circulation loop
between the cold load interface (CLI) and the dewar. MNCIRSPD is the rotational speed
of the miniature centrifugal circulator.
MNCORSPD - NCS COmp Rot SPeeD
A centrifugal compressor compresses the Neon gas in the cracklier loop. MNCORSPD
is the rotational speed of the Neon compressor.
MNCONTRL - NCS CONTRL point tmp (degK)
The computed control temperature is the average of the NCC inlet and outlet Neon gas
temperature.
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Instrument Science Report NICMOS 2003-008
MNPDSTPT - NCS PiD SeT PoinT (degK)
MNPDSTPT is the commanded control temperature set point, a number in a computer
register. No sensor. This temperature drives the system.
MNCRADAT - NCS RAD A Tmp (degC)
Heat at the heat rejection interface (HRI) is removed by the evaporator in the Capillary
Pumped Loop (CPL) and is rejected to the space environment at the radiator surface.
MNCRADAT is the radiator temperature which currently has limits of -70C to +70C.
MNHTREJT - NCS HeaT REJect Tmp (degC)
The work of the neon compressor is transferred through the compressor housing to the
heat rejection interface (HRI). MNHTREJT is the rejection interface (HRI) temperature
which currently has limits of -45C to +45C.
MNPNCOLT - NCS Pri NIC OtLt Tmp (degK)
MNPNCOLT is the primary dewar outlet neon gas temperature.
MNRNCILT - NCS Red NIC InL Tmp (degK)
MNRNCILT is the redundant dewar inlet neon gas temperature.
MNRNCOLT - NCS Red NIC OtLt Tmp (degK)
MNPNCILT is the redundant dewar outlet neon gas temperature.
NDWTMP11 - Camera 1 Mounting Cup temp (degK)
NDWTMP11 is the temperature sensor at the Camera 1 mounting cup. The detector
sits on a square piece of ceramic, and the piece of ceramic is connected to the mounting
cup. The mounting cup is attached to the cold optics bench. This is the selected sensor
which is used to monitor the temperature of the NICMOS detectors.
NDWTMP13 - Camera 3 Mounting Cup temp (degK)
NWTMP13 is the temperature sensor at the Camera 3 mounting cup. The detector sits
on a square piece of ceramic, and the piece of ceramic is connected to the mounting cup.
The mounting cup is attached to the cold optics bench.
NDWTMP14 - Cold Well temp (degK)
The NICMOS cameras are mounted to a cold optics bench. The “cold well” is the container inside the dewar in which the cold optics bench is located. NDWTMP14 is the
temperature of the cold well container.
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Instrument Science Report NICMOS 2003-008
NDWTMP21 - Camera 2 Cold Mask temp (degK)
NDWTMP21 is the temperature sensor at the Camera 2 cold mask and the sensor closest to the NIC2 filter wheel.
NDWTMP22 - Camera 3 Cold Mask temp (degK)
NDWTMP22 is the temperature sensor at the Camera 3 cold mask and the sensor closest to the NIC3 filter wheel. This sensor was added to the temperature table as a possible
aid to grism observers.
How it works
The NICMOS Cryogenic Cooler (NCC) is a two loop mechanical refrigerator, cryocooler and external circulator loops with a heat exchanger between the two loops. In the
cryocooler loop, neon gas is raised to a pressure ratio of 1.6 by a centrifugal compressor
operating at rotational speeds up to about 7300 revolutions per second (rps). The gas flows
from the aftercooler through an all-metal recuperator to the turboalternator where it
expands through the turbine rotor and is cooled to produced refrigeration. The gas leaving
the turbine flows through a cold load interface (CLI) heat exchanger through the low-pressure side of the recuperator back to the compressor inlet. The compressor speed is
controlled in response to varying heat loads (Jedrich et al. 2003).
In the external circulator loop, neon gas is pumped by a centrifugal circulator (~1200
rps) through the CLI to the dewar cooling coils. Heat from the dewar is removed at the
cooling coils and is then transferred from the circulator loop to the cryocooler loop across
the CLI. The flow rate of neon gas through the dewar is maintained at a constant rate by
the circulator.
The heat from the cryocooler loop is conducted through the heat rejection interface
(HRI) to the capillary pump loop (CPL) evaporator where it is transported in the twophase ammonia fluid loop to the radiator. The heat load is dissipated in the radiator isothermally through a series of heat pipes.
A control set-point temperature of 72.4 K (MNCONTRL) was chosen for the first year
of operation, yielding a temperature of ~77.1 K at the detectors (NDWTMP11). The
NDWTMP11 sensor saturates at 77.43 K, providing ~0.33 K margin for the set-point. The
compressor speed (MNCORSPD) will speed up or slow down to maintain the control setpoint temperature. There is a delta T = (4.8+/-0.1) K between the Camera 1 mounting cup
temperature sensor (NDWTMP11) and the neon loop control set-point temperature
(MNCONTRL). Adjusting the control set-point temperature will corresponding raise or
lower the Camera 1 mounting cup temperature.
HST Warm Season
The Earth is closer to the Sun in January than in any other month of the year. The aft
shroud temperature will increase during the HST warm season. The NICMOS detectors
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Instrument Science Report NICMOS 2003-008
are extremely sensitive to temperature variations: new calibration reference files (in particular dark frames) are required for a change of 0.1 K at the detectors in order to provide
science-grade data. During the approach of the warm season, the temperature of the NICMOS detectors increased, and correspondingly decreased once the peak of the warm
season had passed. The compressor speed also increased by ~100 rps during this period.
The NCS control-law is using the neon inlet and outlet temperatures to maintain the
NICMOS instrument at a “constant” temperature. A decrease of 0.05 K in the control-law
set-point temperature was implemented on December 19, 2002 (day 2002.353) to bring
the NICMOS detectors back to their baseline operating temperature of 77.1 K. A corresponding increase of 0.03 K in the set-point temperature was implemented on April 29,
2003 (day 2003.119).
Aft Shroud Heating
Prolong operation of the STIS/MAMA and pointing toward the anti-sun can contribute
to heating of the aft shroud and correspondingly to rising the temperature of NICMOS.
The Space Telescope Imaging Spectrograph (STIS) has two Multi-Anode Microchannel
Array (MAMA) detectors operating in the near and far ultraviolet. During late June and
early July 2003 (4 continuous weeks in a row), near continuous operation of the STIS/
MAMAs resulted in a ~0.1 K temperature increase of NICMOS. MAMA observations can
be scheduled up to 5 orbits in a row and once the MAMAs are powered up, they are not
powered down until an SAA crossing occurs or there are no more observations scheduled
for that day. Each MAMA detector dissipates approximately 22 Watts of heat when it’s
low voltage power supply (LVPS) is on. The high voltage (HV) power supply does not
contribute to the heat load because the HV supply draws little current (Baum, Reinhart,
and Ferguson 1998).
Prolong pointing toward the anti-sun will expose the aft shroud toward the Sun, resulting in heating of the aft shroud. However, to date and due to the random nature of HST
targets on the sky, heating of the aft shroud due to pointing toward the anti-sun has not
been a problem.
NICMOS Temperature Table Data
The FITS binary table software code was tested for a series of NICMOS post-SAA dark
observations, proposal ID: 8791 (N627J3010, N627J3020, N627J3030), obtained on 11/
21/2002. A pair of ACCUM mode darks (exptime=243s) in each camera are automatically
scheduled following passage through the South Atlantic Anomaly (SAA) and before the
first science observation. No science observations are obtained during SAA passage; i.e.,
the NICMOS cameras are transitioned from OPERATE (on) to SAAOPR (off). Following
SAA passage, the NICMOS detectors are transitioned from SAAOPR to OPERATE and
the detectors are commanded to autoflush mode upon transition to OPERATE mode. The
NCS continues to operate during SAA passage.
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Instrument Science Report NICMOS 2003-008
Temperature Table
The NICMOS temperature table contains 14 individual tables, one table for each mnemonic. A listing of the individual table names and their location within the FITS table can
be obtained by using the IRAF/STSDAS task catfits. For example:
> catfits n627j3tgj_epc.fits
EXT# FITSNAME
FILENAME
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
n627j3tgj_epc
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
BINTABLE
EXTVE DIMENS
n627j3tgj.epc
MNCIRSPD
MNCORSPD
MNCONTRL
MNPDSTPT
MNCRADAT
MNHTREJT
MNPNCOLT
MNRNCILT
MNRNCOLT
NDWTMP11
NDWTMP13
NDWTMP14
NDWTMP21
NDWTMP22
BITPI OBJECT
8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
2Fx10R
2Fx40R
2Fx10R
2Fx10R
2Fx10R
2Fx10R
2Fx10R
2Fx10R
2Fx10R
2Fx20R
2Fx20R
2Fx20R
2Fx20R
2Fx20R
The task imhead can be used to display the primary table header to the screen. The primary table header contains a minimum number of FITS keywords. For example:
> imhead n627j3tgj_epc.fits[0] l+
n627j3tgj_epc.fits[0][0][short]:
No bad pixels, min=0., max=0. (old)
Line storage mode, physdim [0], length of user area 648 s.u.
Created Mon 20:01:00 07-Jul-2003, Last modified Tue 00:00:00 01-Jan-1980
Pixel file "n627j3tgj_epc.fits" [NO PIXEL FILE]
EXTEND =
T / File may contain standard extensions
NEXTEND =
14 / Number of standard extensions
GROUPS =
F / image is in group format
DATE
= ’2003-07-08’
/ date this file was written (yyyy-mm-dd)
FILENAME= ’n627j3tgj.epc
’ / name of file
FILETYPE= ’EPC
’
/ type of data found in data file
TELESCOP= ’HST’
INSTRUME= ’NICMOS’
data
EQUINOX =
OPUS_VER=
PDB_VER =
PROCTIME=
ROOTNAME=
PROGRMID=
/ telescope used to acquire data
/ identifier for instrument used to acquire
2000.0 / equinox of celestial coord. system
’OPUS 14.4
’ /
’CCS
’ /
’2003.189:18:17:58.00’
’n627j3tgj
’
/
’627’
/
OPUS software system version number
Project Database version in use
/ Date-Time When Observation Processed
rootname of the observation set
program id (base 36)
Two additional keywords, TSTRTIME and TENDTIME, indicating the start and end time
spanning the data set will be included at a later date.
Table Columns
The first column in each table is time in Modified Julian Date (MJD), and the format is
5####.#####... The sampling time for each mnemonic is not the same. Creating separate
tables allows each table to be fully populated. The second column contains the value of the
7
Instrument Science Report NICMOS 2003-008
respective mnemonic. The IRAF/STSDAS package ttools contains a group of tools to
read, edit, manipulate table entries, and to perform other tasks on tables. A very useful tool
is tread. tread allows inspection of the table without affecting its contents. For example:
> tread n627j3tgj_epc.fits[1]
Column
1
Label __________TIME___________
1 52598.36282
2 52598.36351
3 52598.36421
4 52598.36489999999
5 52598.3656
6 52598.36628999998
7 52598.36699
8 52598.36768
9 52598.36836999999
10 52598.36907
2
__________VALUE__________
1207.565918
1207.565918
1215.420288
1199.71167
1199.71167
1215.420288
1207.565918
1215.420288
1207.565918
1207.565918
The task tdump can be used to display the individual table headers and data to the screen.
The individual table headers contain a subset of the standard FITS keywords. For
example:
> tdump n627j3tgj_epc.fits[1]
TIME
D
%25.16g MJD
VALUE
D
%25.16g rps
MJD_52598
R
%15.7g ""
XTENSION t ’BINTABLE’ extension type
BITPIX
i 8 bits per data value
NAXIS
i 2 number of data axes
NAXIS1
i 20 length of first data axis
NAXIS2
i 10
PCOUNT
i 0 number of group parameters
GCOUNT
i 1 number of groups
TFIELDS i 3
INHERIT b T inherit the primary header
EXTNAME t ’MNCIRSPD’ extension name
EXTVER
i 1 extension version number
ROOTNAME t ’n627j3tgj’ rootname of the observation set
EXPNAME t ’n627j3tgj’ exposure identifier
DATAMIN d 1199.71167000 the minimum value of the data
DATAMAX d 1215.42028800 the maximum value of the data
OBSET_ID t ’j3’ observation set id
OBSERVTN t ’tg’ observation number (base 36)
’’
t
’’
t
/ TABLE PARAMETERS
’’
t
ENGSTART d 52598.36282000 Start time of mnemonic data in table (MJD)
ENGEND
d 52598.36907000 End time of mnemonic data in table (MJD)
MNEMONIC t ’MNCIRSPD’ Mnemonic name
MN_DESCR t ’Ncs CIrc Rot SPeeD’ Mnemonic description
MN_AVERG d 1208.35137940 Average value of mnemonic in table
MN_STDEV d 5.79542263 Standard deviation of mnemonic values in table
’’
t
’’
t
/ MNEMONIC TABLE DEFINITION
’’
t
TTYPE1
t ’TIME’ Mnemonic readout time
TFORM1
t ’1D’ data format for time: REAL*8
TUNIT1
t ’MJD’ units for time: Modified Julian Date
TTYPE2
t ’VALUE’ Mnemonic value at readout time
TFORM2
t ’1D’ data format for mnemonic value: REAL*8
TUNIT2
t ’rps’ units for mnemonic value
TTYPE3
t ’MJD_52598’ label for field
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Instrument Science Report NICMOS 2003-008
TFORM3
TUNIT3
TDISP3
t ’1E’ format of field
t ’’ column units
t ’G15.7’ display format
52598.36282
1207.565918
52598.36351
1207.565918
52598.36421
1215.420288
52598.36489999999
1199.71167
52598.3656
1199.71167
52598.36628999998
1215.420288
52598.36699
1207.565918
52598.36768
1215.420288
52598.36836999999
1207.565918
52598.36907
1207.565918
0.36282
0.36351
0.36421
0.3649
0.3656
0.36629
0.36699
0.36768
0.36837
0.36907
Note that the keywords DATAMAX and DATAMIN will be changed to MAXVALUE and
MINVALUE, respectively, at a later date.
spt file
A snap shot of the engineering telemetry is obtained at the start of each HST observation and sent to the ground with the science data. For NICMOS observations, each time a
detector is read-out, an engineering snap shot is obtained. Selected engineering information including temperatures are extracted from the snap shot during OPUS pipeline
processing and stored in the spt file. The task imhead can be used to display to the screen
the spt file temperatures. For example:
> imhead n627j3tgq_spt.fits[1] l+ | grep temp
NDWTMP11=
77.176 / Camera 1 Mounting Cup temp (degK)
NDWTMP12=
1.0E-05 / Camera 2 Mounting Cup temp (degK) - disabled
NDWTMP13=
76.28 / Camera 3 Mounting Cup temp (degK)
NDWTMP14=
76.0556 / Cold Well temp (degK)
NDWTMP15=
1.0E-05 / Nitrogen Fill Value Input temp (degK) - disable
NDWTMP16=
72.8805 / N2 Tank Aft temp (degK)
NDWTMP21=
112.511 / Camera 2 Cold Mask temp (degK)
NDWTMP22=
112.412 / Camera 3 Cold Mask temp (degK)
NDWTMP23=
125.65 / Vapor Cooled Shield Forward temp (degK)
NDWTMP24=
113.15 / Vapor Cooled Shield Aft temp (degK)
NDWTMP25=
112.902 / Vapor Cooled Shield MID temp (degK)
NDWTMP31=
193.515 / Thermoelectric Cooler Inner 1 Base temp (degK)
NDWTMP32=
192.735 / Thermoelectric Cooler Inner 2 Finger temp(degK
NDWTMP33=
193.046 / Thermoelectric Cooler Inner 2 Base temp(degK)
NDWTMP34=
193.462 / Thermoelectric Cooler Inner 1 Finger temp (degK
NDWTMP35=
193.671 / Thermoelectric Cooler Inner Shield temp (degK)
NDWTMP41=
222.782 / Thermoelectric Cooler Outer 1 Base temp (degK)
NDWTMP42=
222.303 / Thermoelectric Cooler Outer 1 Finger temp (degK
NDWTMP43=
223.203 / Thermoelectric Cooler Outer 2 Base temp (degK)
NDWTMP44=
222.045 / Thermoelectric Cooler Outer 2 Finger temp (degK
NDWTMP45=
224.729 / Outer shield temp (degK)
For comparison, temperatures from the spt file and the temperature table are presented
in Table 2. The temperature values in the spt file depend upon the time of the snap shot
which is slightly before the start of the observation. A MULTIACCUM mode exposure of
N reads will have N+1 snap shots in the spt file, which includes the zeroth read snap shot.
9
Instrument Science Report NICMOS 2003-008
Note that the time sampling of the temperatures in the spt file will be different than the
sampling time for the temperature table.
Table 2. SPT and temperature table temperatures (PSTRTIME=52598.36532407).
Mnemonic
SPT
(degK)
Temperature
Table
(degK)
Description
NDWTMP11
77.176
77.194
Camera 1 Mounting Cup temp
NDWTMP13
76.28
76.279
Camera 3 Mounting Cup temp
NDWTMP14
76.0556
76.046
Cold Well temp
NDWTMP21
112.511
112.510
Camera 2 Cold Mask temp
NDWTMP22
112.412
112.412
Camera 3 Cold Mask temp
Plotting Package
The time column is MJD, and the range of time values are rather small. sgraph uses
single precision, which would result in the small variations in the time being lost when
plotted. The task tcalc can be used to subtract a constant from the time column values
allowing plotting using the sgraph task. For example:
> tcalc n627j3tgj_epc.fits[3] MJD_52598 "TIME - 52598"
The constant subtracted time values are written to a new table column, which for this
example is called ”MJD_52598.” The table name and the two columns (MJD_52598,
VALUE) must be specified on the command line when plotting. The sgraph task allows
scaling parameters (wl, wr, wb, wt) to be changed from the command line. For example:
> sgraph "n627j3tgj_epc.fits[3] MJD_52598 VALUE" wb=72 wt=73
A plot of the entries for each individual mnemonic in the temperature table is presented at
the end of this ISR. There appears to be small oscillations in the rotational speed of the circulator and compressor speeds. This is most likely due to the temperature control-law
acting through the control algorithm and is not a problem. A few sensors exhibit very
small variations in temperature (+/- 0.025 K) which are well below the stability requirement of +/- 0.5 K and show the stability provided by the NCS.
Summary
Nine NICMOS Cooling System (NCS) mnemonics and five temperature sensors are
extracted from the engineering telemetry and bundled together into the NICMOS Temperature Table. The table is provided as an aid for use in calibration, temperature monitoring,
and as a convenience to science data users. The Camera 1 mounting cup temperature
(NDWTMP11) is the selected temperature which is used to monitor the temperature of
10
Instrument Science Report NICMOS 2003-008
the NICMOS detectors. The test data show that the mounting cup temperature is stable to
+/- 0.025 K over the time span of the observation (exptime=243s).
Acknowledgements
We would like to thank Larry Petro (TEL) for proof reading the ISR and for his assistance
in checking the accuracy of the NCS hardware layout.
References
Baum, S., Reinhart, M., and Ferguson, H. 1998, “STIS MAMA High and Low Voltage
Management around the SAA,” STIS Technical Instrument Report, STIS-TIR-98-010,
Space Telescope Science Institute, Baltimore, MD 21218
Boeker, T., Bergeron, L.E., Mazzuca, L., Sosey, M., and Xu, C. 2002, “NICMOS Detector
Performance in the NCS era,” in 2002 HST Calibration Workshop, ed. S. Arribas, A.
Koekemoer, and B. Whitmore, Space Telescope Science Institute, Baltimore, Maryland.
Boeker, T., Bergeron, L.E., Mazzuca, L., Sosey, M., and Xu, C. 2003, “The NICMOS
revival: detector performance in the NCS era,” in IR Space Telescopes and Instruments,
SPIE Vol 4850, J.C. Mather ed., 935.
Jedrich, N.M., Gregory, T.H., Zimbelman, D., Cheng, E.S., Petro, L.D., Cottingham, C.E.,
Buchko, M.T., Kaylor, M.L., and Dolan, F.X. 2003, “A cryogenic cooling system for
restoring IR science on the Hubble Space telescope,” in IR Space Telescopes and Instruments, SPIE VOL 4850, J.C. Mather ed., 1058.
Schultz, A.B., Calzetti, D., Arribas, S., Boeker, T., Dickinson, M., Malhotra, S., Mazzuca,
L.M., Mobasher, B., Noll, K., Roye, E., Sosey, M., Wiklind, T., and Xu, C. 2002, “NICMOS Status,” in 2002 HST Calibration Workshop, ed. S. Arribas, A. Koekemoer, and B.
Whitmore, Space Telescope Science Institute, Baltimore, Maryland.
Schultz, A.B., Sosey, M., Mazzuca, L.M., Bushouse, H.A., Dickinson, M., Boeker, T.,
Calzetti, D., Arribas, S., Bergeron, L.E., Freudling, W., Holfeltz, S.T., Malhotra, S.,
Mobasher, B., Noll, K., Roye, and E., Xu, C. 2003, “Post-NCS Performance of the HST
NICMOS,” in IR Space Telescopes and Instruments, SPIE VOL 4850, J.C. Mather ed.,
858.
Swain, S. 2000, “Engineering Data List for the Aft Shroud Cooling System/NICMOS
Cooling System (ASCS/NCS),” CDRL No. DM-02, Revision C, June 28, 2000, prepared
by Lockheed Martin, NASA Goddard Space Flight Center, Greenbelt, MD 20771
11
Instrument Science Report NICMOS 2003-008
Figure 1: Overview of HST showing the instrument bay relative to the aperture door.
NCS Internal Layout
CryoVent
Insert
COS TAR
Y Harness
CPL
ESM
NCC
CASH
NCS
Radiator
Figure 2: NICMOS Cooling System (NCS) as installed on HST (looking from aperture
toward aft bulkhead). The NCS hardware consist of the NICMOS Cryogenic Cooler
(NCC), a Capillary Pumped Loop (CPL)/Radiator assembly, an Electronics Support Module (ESM), and associated interface Cross Aft Shroud Harness (CASH).
12
Instrument Science Report NICMOS 2003-008
NCS Circ Rot Speed
NCS Comp Rot Speed
1230
7200
7175
Value (rps)
Value (rps)
1220
1210
7150
7125
7100
1200
7075
7050
1190
.364
.366
.364
.368
.368
Time (MJD_52598)
Time (MJD_52598)
NCS Contrl Point Tmp
NCS Pid Set Point Tmp
72.475
77.25
72.45
Value (degK)
Value (degK)
.366
72.425
77.225
77.2
77.175
72.4
77.15
72.375
.364
.366
.364
.368
Time (MJD_52598)
.366
.368
Time (MJD_52598)
NCS Rad A Tmp
NCS Heat Reject Tmp
5.4
Value (degC)
Value (degC)
-15.5
-15.75
-16
5.2
5
4.8
-16.25
.364
.366
.364
.368
.366
.368
Time (MJD_52598)
Time (MJD_52598)
13
Instrument Science Report NICMOS 2003-008
NCS Pri NIC OltLt Tmp
NCS Red NIC InL Tmp
65
81
80.95
Value (degK)
Value (degK)
64.95
80.9
80.85
64.9
64.85
80.8
64.8
80.75
.364
.366
.364
.368
NIC1 Mount Cup Tmp
NCS Red NIC OtLt Tmp
80.75
77.25
80.725
77.225
Value (degK)
Value (degK)
.368
Time (MJD_52598)
Time (MJD_52598)
80.7
80.675
77.2
77.175
80.65
77.15
.364
.366
.368
.364
.366
.368
Time (MJD_52598)
Time (MJD_52598)
NIC3 Mount Cup Tmp
NIC Cold Well Tmp
76.35
76.1
76.325
76.075
Value (degK)
Value (degK)
.366
76.3
76.05
76.025
76.275
76
76.25
.364
.366
.364
.368
.366
.368
Time (MJD_52598)
Time (MJD_52598)
14
Instrument Science Report NICMOS 2003-008
NIC3 Cold Mask Tmp
112.6
112.6
112.55
112.55
Value (degK)
Value (degK)
NIC2 Cold Mask Tmp
112.5
112.45
112.5
112.45
112.4
112.4
.364
.366
.364
.368
.366
.368
Time (MJD_52598)
Time (MJD_52598)
15