After more than three years of inactivity, and thanks
to a new cryogenic refrigerator, the Hubble Space
Telescope’s Near Infrared Camera and Multi Object
Spectrometer (NICMOS) today debuts various breathtaking
views of galaxies in several stages of development.

The first NICMOS test images demonstrate its powerful new
capability for making remarkable discoveries unique to
space-based near-infrared astronomy. The NICMOS’ penetrating
vision sliced through the edge-on dusty disk of a galaxy,
NGC 4013, to peer all the way into the galaxy’s core.
Astronomers were surprised to see what appears to be an
edge-on ring of stars, 720 light-years across, encircling
the nucleus. Though such star-rings are not uncommon in
barred-spiral galaxies, only NICMOS has the resolution to
see the ring buried deep inside an edge-on galaxy.

Shifting its infrared vision to our stellar backyard, NICMOS
peeled back the outer layers of the Cone nebula (also
photographed by Hubble’s Advanced Camera for Surveys in
April) to see the underlying dusty “bedrock” in this stellar
“pillar of creation.”

“It is fantastic that we have restored Hubble’s infrared
eyesight. NICMOS has taken us to the very fringes of the
Universe and to a time when the first galaxies were formed.
We can’t wait to get back out there,” said Dr. Rodger
Thompson, NICMOS Principle Investigator, University of
Arizona, Tucson.

Installed on Hubble in February 1997, NICMOS used infrared
vision to probe dark, dusty, never-before-seen regions of
space with the optical clarity that only Hubble can provide.
Its infrared detectors operated at a very cold temperature
(minus 351 degrees Fahrenheit, which is minus 213 degrees
Celsius or 60 degrees Kelvin).

To keep the detectors cold, NICMOS was encased in a thermos-
like container filled with solid nitrogen ice. It was
expected that the solid nitrogen ice would last
approximately four years. However, the ice evaporated about
twice as fast as planned and was depleted after only 23
months of NICMOS science operations. In 1999 — with its
supply of ice exhausted — NICMOS became dormant.

Determined not to be defeated, NASA scientists and engineers
devised a plan to restore NICMOS to life. They turned to a
new mechanical cooling technology, jointly developed by NASA
and the U.S. Air Force. The NICMOS Cooling System (NCS) was
built by NASA’s Goddard Space Flight Center, Greenbelt, Md.,
and the Creare Corporation, Hanover, N.H.

The mechanical cooler operates on principles similar to a
modern home refrigerator. It pumps ultra-cold neon gas
through the internal plumbing of the instrument. At its core
are three miniature, high-tech turbines that spin at rates
up to about 430,000 rpm. Since the speed of the turbines can
be adjusted at will, the NICMOS light sensors can be
operated at a more optimal temperature than was possible
before, about 77 degrees Kelvin (minus 321 degrees

The NICMOS cooling system is virtually vibration-free, an
important aspect for Hubble since vibrations can affect
image quality in much the same way that a shaky camera
produces blurred pictures.

“The Hubble Space Telescope Servicing Mission 3B is now
demonstrated to be a complete success. We had 100 percent
servicing mission success, and now we have 100 percent
performance success for the newly installed NICMOS Cooling
System,” said Dr. Ed Cheng, HST Development Project
Scientist from NASA’s Goddard Space Flight Center.

Astronauts installed the NCS inside Hubble during the fifth
and final spacewalk of Servicing Mission 3B on March 8,
2002. On March 18, the NCS was turned on via commands sent
from the Space Telescope Operations Control Center at
Goddard. It has continued to operate flawlessly ever since.
The deep interior of the NICMOS reached the target
temperature of 70 degrees Kelvin (minus 333 degrees
Fahrenheit) on April 11. Most of the internal heat had been
removed from the instrument, and the NCS stabilized itself
at this temperature. On April 19, NICMOS was brought up to a
fully operational state and testing of its internal
condition began. Since then, fine adjustments have been made
to the settings of the NCS to optimize the instrument for
best performance.

Images and additional information are available on the Web