June 7, 2002. Copyright 2002. Graphic News. All rights reserved.

HubbleÕs Infra-red Camera is back in business

LONDON, June 7, Graphic News: After more than three years of inactivity, the Near Infra-red Camera and Multi-Object Spectrometer (NICMOS) has reopened its Ònear-infra-red eyesÓ on the universe, snapping breathtaking views from the craggy interior of the star-forming Cone Nebula.

NICMOS peeled back the outer layers of the Cone Nebula (right) -- also photographed by HubbleÕs Advanced Camera for Surveys in April (left), to see the underlying dusty ÒbedrockÓ in this stellar Òpillar of creation.Ó

ÒIt is fantastic that we have restored HubbleÕs infra-red eyesight. NICMOS has taken us to the very fringes of the Universe and to a time when the first galaxies were formed. We canÕt wait to get back out there,Ó said Dr. Rodger Thompson, NICMOS Principal Investigator at the University of Arizona, Tucson. 

Installed on Hubble in February 1997, NICMOS used infra-red vision to probe dark, dusty, never-before-seen regions of space with the optical clarity that only Hubble can provide. Its infra-red detectors operated at a very cold temperature (minus 351 degrees Fahrenheit, minus 213 degrees Centigrade or 60 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 NASAÕs Goddard Space Flight Center, Greenbelt, MD, and the Creare Corporation, Hanover, NH. 

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 Kelvin (minus 321 degrees Fahrenheit, minus 196 degrees Centigrade). 

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.

Astronauts installed the NCS inside Hubble during the fifth and final spacewalk of Servicing Mission 3B on March 8, 2002. Ten days later 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.

ÒThe 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,Ó said Dr. Ed Cheng, HST Development Project Scientist from NASAÕs Goddard Space Flight Center. 

/ENDS

Sources: NASA, The NICMOS Group (STScI, ESA) and The NICMOS Science Team (Univ. of Arizona)