After the depletion of cryogen in the dewar NICMOS was unavailable for science from January 1999 to March 2002. To restore and conserve an infrared capability on HST, NASA, together with Creare, Inc., developed the NICMOS Cooling System (NCS). After its installation during Servicing Mission 3B, in March, 2002, the NCS has enabled continued operation of NICMOS by cooling the instrument and its detectors to temperatures around 77 K. This is achieved by a closed-loop circuit which runs cryogenic gas through a coil inside the NICMOS dewar.
The NCS consists of three major subsystems:
Additional elements of the NCS are the Power Conversion Electronics (PCE) which provide the up to 400 W power needed by the cooler, and the Electronic Support Module (ESM) which contains a microprocessor to control the heat flow.
Information about the actual on-orbit characteristics of the NCS such as power consumption, lowest possible operating temperature, and temperature stability can be found in the NICMOS Instrument Handbook. Additional information regarding the NCS can be found in the following publications and Instrument Science Reports (ISRs) listed below.
NCS Related Links:
For more specific details on NCS, follow the links to the documents listed below.
Advisories:
Important updates, discoveries and developments
that could potentially affect NICMOS observations,
calibration, or data analysis.
FAQs:
Frequently Asked Questions.
Handbooks:
The NICMOS Instrument Handbook is the primary
guide regarding the characteristics and use of
the instrument. The HST Data Handbook is the
primary guide for calibration, reduction and analysis
of NICMOS data.
Instrument Science Reports:
ISRs are technical reports written by members
of the NICMOS Group about various aspects of the
instrument and data. They usually contain in-depth
information about specific topics.
NICMOS ISR 2003-008: NICMOS Temperature Table
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.
NICMOS ISR 2000-006: Results From the NCC/NICMOS Spare Detector June 2000 EMI Test
Analysis of power spectra and images obtained with a NIC3 flight spare detector, operate in conjunction with the NICMOS Cryo-Cooler (NCC) and mated with flight-like ground connections, indicate the total absence of any NCC indcued electromagnetic interference.
NICMOS ISR-2000-003 Results of the June 2000 NICMOS-NCS EMI Test
We summarize the findings of the NICMOS+NCS EMI Tests conducted at Goddard Space
Flight Center in June 2000. No NCS-induced noise was detected over a wide range of
read-out sequences and compressor speeds. The sensitivity of the test data was close to
on-orbit performance, thus the improved NCS design appears well suited for restoring
NICMOS capabilities without degrading its sensitivity.
NICMOS ISR-99-001: Analysis, Results and Assessment of the NICMOS Warm-up Monitoring Program
We summarize the results of the NICMOS warmup monitoring program. We estimate NICMOS performance during the NCS era, and briefly discuss possible implications for the cycle 9 calibration program.
NICMOS ISR-99-001: Analysis, Results and Assessment of the NICMOS Warm-up Monitoring Program
We summarize the results of the NICMOS warmup monitoring program. We estimate NICMOS performance during the NCS era, and briefly discuss possible implications for future calibration programs.
NICMOS TIR 98-001: NICMOS/NCS EMI Test Data Results
Data from the NICMOS/Nicmos Cooling System Electromagnetic Interference test is summarized.
NICMOS ISR-98-001: Cosmic Ray Persistence in NICMOS Data
In this report, we discuss the implications of cosmic ray persistence for the overall quality of NICMOS data, quantify the tradeoff between data quality and timing of observations relative to SAA passages, and discuss possible strategies to minimize the problem.
Papers and Proceedings:
Selected NICMOS related published papers and workshop
proceedings.
Paper from 2002 SPIE Meeting: A Mechanical Cryogenic Cooler for the Hubble Space Telescope
Nicholas Jedrich, Darell Zimbelman, Walter Swift, Francis Dolan
Presentation from 2002 SPIE Meeting: A Cryogenic Cooling System for Restoring IR Science on the Hubble Space Telescope
Nicholas M. Jedrich, Teri H. Gregory a , Darrell Zimbelman, Edward S. Cheng, Larry D. Petro,,Christine E. Cottingham, Matt T. Buchko, Marc L. Kaylor e , Francis X. Dolan
Properties of PACE-I HgCdTe Detectors in Space - the NICMOS Warm up Monitoring Program
EMI Noise Properties of the NICMOS Cooling System as Seen by a NIC3 Flight Spare Detector
Tutorials:
Cookbook style instructions, prescribed procedures, and
helpful tips.
Space Telescope Analysis Newsletters:
STANs contain useful information regarding
calibration and data reduction.
