NICMOS

NICMOS
Name	NICMOS
Operator	National Aeronautics and Space Administration (NASA)
Spacecraft	Hubble Space Telescope
Launched	Space Shuttle Discovery (STS-82)
Launch date	1997-02-14
Type	Infrared camera and spectrometer
Wavelength	0.8–2.5 μm (imaging), 0.8–2.5 μm (spectroscopy)
Instruments	Three near-infrared cameras; grisms; coronagraph
Status	Decommissioned (thermal issues; cryocooler installed 2002; operational until 2008)

NICMOS

NICMOS was a near-infrared imaging and spectroscopic instrument installed on the Hubble Space Telescope that provided high-resolution observations across the near-infrared band. Developed and delivered through partnerships among National Aeronautics and Space Administration, the Jet Propulsion Laboratory, and the Space Telescope Science Institute, NICMOS enabled studies of stellar formation, galaxy evolution, and extrasolar planetary environments. Its sensitivity complemented instruments like the Wide Field and Planetary Camera 2 and later Advanced Camera for Surveys, bridging observations toward facilities such as the Spitzer Space Telescope and James Webb Space Telescope.

Overview

NICMOS operated as a cryogenically-cooled near-infrared camera and spectrometer, optimized for wavelengths roughly 0.8–2.5 micrometers, filling a niche between visible instruments on the Hubble Space Telescope and mid-infrared missions like the Spitzer Space Telescope. The instrument suite contained three cameras with differing plate scales and a coronagraph, designed to observe targets ranging from proto-planetary disks in Orion Nebula to high-redshift galaxies in deep fields like the Hubble Deep Field. NICMOS observations were central to programs led by teams from institutions including the University of Arizona, California Institute of Technology, and European Southern Observatory collaborators.

Design and Instruments

NICMOS comprised three independent near-infrared cameras (Camera 1, Camera 2, Camera 3) using mercury-cadmium-telluride (HgCdTe) detector arrays manufactured by detectors groups at Raytheon, operated with focal plane assemblies produced with input from Jet Propulsion Laboratory. Each camera provided distinct field of view and pixel scale: a high-resolution narrow-field channel, an intermediate channel, and a wide-field channel suited for surveys. The instrument incorporated a coronagraphic hole for high-contrast imaging of faint companions and circumstellar disks, and low-resolution grisms for slitless spectroscopy used in programs connected to teams at Space Telescope Science Institute and Max Planck Institute for Astronomy. Passive and active cooling strategies were central to the design, initially relying on a solid nitrogen cryogen dewar developed with contributions from Lockheed Martin contractors.

Operations and Mission History

Installed during STS-82 in 1997, NICMOS replaced earlier thermal designs after initial on-orbit cooling challenges required rapid adjustments by the Hubble Space Telescope operations teams. Early depletion of the solid nitrogen cryogen led to suspension of routine NICMOS science until a specially developed cryocooler was designed by engineers at the Goddard Space Flight Center and the Ball Aerospace team. A successful installation of the Near Infrared Camera and Multi-Object Spectrograph cryocooler during STS-109 or related servicing efforts restored long-term operations in 2002, after which NICMOS resumed science for several years. Operational planning and scheduling integrated NICMOS observing programs with outreach and archival programs at the Space Telescope Science Institute and international partners including European Space Agency investigators.

Scientific Contributions and Discoveries

NICMOS contributed key results in star formation, exoplanetary science, and cosmology. High-resolution imaging of protostellar regions in the Orion Nebula and Taurus Molecular Cloud elucidated disk morphologies and multiplicity statistics, complementing spectroscopic studies by teams from Smithsonian Astrophysical Observatory and University of California, Berkeley. NICMOS coronagraphic imaging directly imaged debris disks around stars like those observed by groups at Carnegie Institution for Science and identified candidate substellar companions, informing follow-up with facilities such as the Keck Observatory and Very Large Telescope. Deep NICMOS surveys probed galaxy assembly at redshifts explored subsequently by Hubble Ultra Deep Field programs and work by researchers at Princeton University and Harvard University, detecting rest-frame optical emission from galaxies at z > 1 and constraining stellar mass build-up complementary to Chandra X-ray Observatory and Spitzer datasets. NICMOS slitless spectroscopy enabled measurements of emission lines (e.g., H-alpha) in distant galaxies used in studies led by California Institute of Technology and University of Cambridge investigators.

Calibration, Data Processing, and Performance

Calibration of NICMOS involved dark current characterization, flat-fielding, and correction for detector nonlinearity developed by teams at the Space Telescope Science Institute in collaboration with the Jet Propulsion Laboratory and detector manufacturers. The NICMOS calibration pipeline evolved to address issues including variable bias levels, persistence, and temperature-dependent sensitivity changes noted in engineering assessments at Goddard Space Flight Center. Archival data reduction techniques, adopted by researchers at European Southern Observatory and National Optical Astronomy Observatory, included advanced sky subtraction and point-spread-function fitting methods to exploit NICMOS's diffraction-limited performance. Photometric and spectroscopic standards from institutions such as South African Astronomical Observatory and Royal Greenwich Observatory aided cross-instrument calibration against contemporaneous observations from Wide Field Camera 3 and ground-based telescopes.

Upgrades, Servicing, and Decommissioning

Following early cryogen depletion, a dedicated cryocooler development effort culminated in a cooling system installed during a servicing mission coordinated by Space Shuttle Columbia program teams and executed with participation from the Hubble Space Telescope project office. The instrument saw hardware and software updates applied during servicing missions aligned with crews and contractors from Johnson Space Center and Marshall Space Flight Center, extending NICMOS science life into the 2000s. Performance degradation, changing priorities toward newer instruments such as Wide Field Camera 3 and budgetary considerations at NASA, led to gradual retirement of routine NICMOS operations and its decommissioning from active science use by the late 2000s. NICMOS data remain in the Mikulski Archive for Space Telescopes and continue to support legacy science alongside data from observatories including James Webb Space Telescope and Atacama Large Millimeter/submillimeter Array.

Category:Spacecraft instruments