The Hubble Space Telescope Second Servicing Mission (SM-2)

Near Infrared Camera and Multi-Object Spectrometer (NICMOS)

The near infrared spectral region is now a cutting-edge research arena for studying our Universe's basic nature: probing the past, present, and future of our Universe, and determining how galaxies, stars and planetary systems form.

NICMOS (Near Infrared Camera and Multi-Object Spectrometer), when installed in the Hubble Space Telescope (HST) during the Second Servicing Mission (SM-2) in 1997, provides a new tool to focus HST's powerful optics on observations crucial to answering key questions within these research areas.

What is NICMOS and what kind of science can it do?

NICMOS is an HST instrument that will provide the capability for infrared imaging and spectroscopic observations of astronomical targets. Infrared light is emitted in the electromagnetic spectrum at wavelengths human eyes cannot see.

Infrared wavelengths are longer and their frequency lower than the light our eyes use to see the world (between 0.4 and 0.7 micrometers). NICMOS "sees" light with wavelengths between 0.8 and 2.5 micrometers -- longer than the human-eye limit.

To study very distant objects, astronomers must observe longer, redder wavelengths, such as the near infrared. NICMOS's near infrared capabilities will provide views of objects too distant for research by current HST optical and ultraviolet instruments. The light from such objects is shifted in wavelength toward the infrared by the expansion of the universe. NICMOS will probe objects created near the beginning of the universe.

NICMOS sees further back in time and farther away in distance.

NICMOS sees through obscuring dust to view how stars and planets are formed.

Most celestial births, such as the birth of planets and stars occur inside dark masses of dust and gas -- obscuring clouds of material that shield these stellar birthplaces from even HST's current view.

NICMOS will change that. Infrared light from forming stars and planets penetrates dust more easily than light at optical wavelengths. NICMOS's detectors can probe through obscuring material to give clear pictures of star and planetary birth -- much like your eyes see red glows of a sunset: dust in our atmosphere lets the red light through, while blue light scatters away. And, NICMOS will provide detailed imaging in infrared bands of planetary atmospheres, much like the infrared weather images of Earth.

NICMOS, the Incredibly Cool Machine

The sensitive infrared detectors in NICMOS must operate at very cold temperatures, 58 degrees Kelvin or minus 355 degrees Fahrenheit. NICMOS keeps its detectors cold inside a cryogenic dewar containing frozen nitrogen ice. The dewar (a thermally insulated container much like a thermos bottle), cools the detectors for up to five years, much longer than any previous space experiment. NICMOS is HST's first cryogenic instrument.

Basic Components of NICMOS

NICMOS contains three cameras, each with a different spatial resolution. Camera 1 has the highest resolution for very fine detail pictures at the shorter near infrared wavelengths. At longer wavelengths, Camera 2 has the next highest resolution for detailed pictures and Camera 3 has a much wider field of view to encompass extended objects. Each camera has its own wheel of filters and optical components. Individual cameras can operate independently while other cameras also are taking images.

NICMOS is much more than a camera. It also is a spectrometer, a cornograph, and a polarimeter. The filter wheels for cameras 1 and 2 contain polarizers for polarimetric observations. The wheel for camera 3 contains grisms (a combination of a grating and a prism) for spectroscopy. Camera 2 also contains special masks for coronographic observations, which mask the light from a bright object to allow nearby faint objects to be seen.

Who Does What?

The University of Arizona (UA) under contract with NASA's Goddard Space Flight Center, heads the development of NICMOS. Dr. Rodger I. Thompson of UA's Steward Observatory is the principal investigator. The major subcontractors are Ball Aerospace Systems Group, Boulder, Colo. and Rockwell International Corp., Thousand Oaks, Calif. Following its installation on the HST and calibration, observing time on NICMOS will be allocated on a competitive basis to scientists throughout the world. The operation of NICMOS will be managed by the Space Telescope Science Institute in Baltimore, Md.

NICMOS' Physical Characteristics

Size 7.1 ft x 2.9 ft x 2.9 ft

(2.2 m x 0.89 m x 0.89 m)

Weight 815 lbs (370 kg)

Cryogen Capacity 239.2 lbs (108.5 kg)

Cryogen life 5 years

Cameras 3

Field of View 51.5 x 51.5 arcsec

17.5 x 17.5 arcsec

11.0 x 11.0 arcsec

Detectors 3 HgCdTe arrays

256 x 256 pixels

For Additional Information Contact:

Tammy Jones

Goddard Space Flight Center

Office of Public Affairs

(301) 286-5566

Internet: http:// www.gsfc.nasa.gov

Space Telescope Science Institute

Office of Public Outreach

(410) 338-4707

Internet: http://www.stsci.edu

NICMOS homepage

http://www.ball.com/aerospace/hst.html