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:
- a cryocooler which provides the mechanical cooling,
- a Capillary Pumped Loop (CPL) which transports the heat dissipated by the cryocooler to an external radiator, and
- a circulator loop which transports heat from the inside of the NICMOS dewar to the cryocooler via a heat exchanger.
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:
- A more detailed description of the NCS subsystems
- NASA Goddard Space Flight Center NICMOS Cooling System web site
- Nicmos Turbo-Brayton Cooler: Photograph & Schematic
- NICMOS Cryocooler Independent Science Review (ISR) Report March 1999
- Aft Shroud Cooling System/NICMOS Cooling System Document (postscript).
- Cryogenics & Fluids Home Page, NASA GSFC Code 552
- NICMOS Cooler flown on STS-95 as part of the HST Orbital Systems Test (HOST) payload
- NICMOS Cooler Performance on STS-95
- Creare Inc., makers of the miniature Turbo-Brayton cooler to be used in the NICMOS Cooling System (NCS)
- NICMOS cutaway
- Filter Wheel Mechanism schematic
For more specific details on NCS, follow the links to the documents listed below.
NICMOS NCS Documentation
AdvisoriesImportant updates, discoveries and developments that could potentially affect NICMOS observations, calibration, or data analysis.
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.
A.B. Schultz 01 Sep 2003
Glenn Schneider 06 Nov 2000
S. Holfeltz 28 Sep 2000
T. Boker 22 Feb 1999
T. Boker 22 Feb 1999
L. Bergeron 04 Nov 1998
J. Najita 25 Feb 1998
Papers and ProceedingsSelected 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
Cookbook style instructions, prescribed procedures, and helpful tips.
Space Telescope Analysis Newsletters
STANs contain useful information regarding calibration and data reduction.