Space Infrared Telescope Facility

The Space Infrared Telescope Facility (SIRTF) was the former name of the Spitzer Space Telescope. It was launched aboard a Delta 2 rocket from Cape Canaveral, Florida at 1:35:39 a.m. eastern daylight time on August 25, 2003. The Space Infrared Telescope Facility (SIRTF) was renamed as the Spitzer Space Telescope on December 18, 2003 after the late Dr. Lyman Spitzer, Jr.

SIRTF spacecraft (Spitzer) is an infrared space telescope which allows astronomers to study everything from asteroids to distant galaxies. SIRTF is a NASA mission managed by the Jet Propulsion Laboratory.

SIRTF’s main scientific goals include looking for extra-solar planets, brown dwarfs, protoplanetary disks, infrared-bright galaxies, active galactic nuclei and extremely distant galaxies whose light has been red-shifted well into the infrared. The spacecraft will allow scientists to view the universe as it was billions of years ago and to help them understand how and when the first objects were formed and what their composition is.

The Space Infrared Telescope Facility (SIRTF) spacecraft was placed in heliocentric orbit where the spacecraft slowly moved away from the Earth. This limited the amount of terrestrial infrared radiation SIRTF (Spitzer) would have to deal with and thus reduce the amount of liquid helium used to keep the telescope’s sensitive instruments cool. An interesting design innovation of the SIRTF spacecraft was that it was launched ‘warm’ and the outer space environment allowed it to radiatively cool which also reduced the amount of liquid helium required and reduced spacecraft development costs.

Instruments

The spacecraft’s three instruments are a camera, spectrograph and imaging photometer. The instruments are sensitive to infrared light at wavelengths between 3 and 180 microns.

History of the Space Infrared Telescope Facility (SIRTF)

SIRTF (now called Spitzer) is one of the four original Great Observatory missions. The other three are the Hubble Space Telescope, Chandra X-Ray Observatory and Compton Gamma Ray Observatory. SIRTF (Spitzer) does not operate in Earth Orbit like the other three great observatories

Plans for SIRTF date back to the 1970’s, when NASA considered flying an infrared telescope in the space shuttle’s cargo bay on multiple missions. By the mid 1980’s the design had evolved into a free-flying spacecraft to be launched on the space shuttle or a large expendable booster. In the 1990’s the SIRTF design was changed several times due to budget pressures. It was down-sized from a 5700 kg spacecraft that was going to be launched by a Titan 4 to a 750 kg spacecraft that was launched by the Delta 2.

The first images from SIRTF were taken shortly after launch as part of a systems check. For the first 60 days after launch SIRTF underwent a check out period, followed by 30 days of scientific instrument calibration.

The science mission at the time of launch was scheduled to last 2.5 years. The mission has potential to last 5 years and by that time SIRTF (Spitzer) may deplete its liquid helium which is used for cooling the spacecraft and it may drift too far from the Earth.

On 18 December 2003, NASA Administrator Sean O'Keefe announced that NASA's Space Infrared Telescope Facility had been renamed as the Spitzer Space Telescope. It was named in honour of the late Dr. Lyman Spitzer Jr., one of the 20th century's most distinguished scientists. The new name was chosen after an international contest sponsored by NASA. More than 7,000 names and supporting essays were submitted, with more than a third coming from outside the United States. Jay Stidolph, a Canadian resident of Fort Nelson, British Columbia, submitted the winning entry.

Please note the correct abbreviation is SIRTF and not SIRF.

Related Books:

Planet Quest: The Epic Discovery of Alien Solar Systems by Ken Croswell
From Amazon.com

Distant Wanderers: The Search for Planets Beyond the Solar System by Bruce Dorminey
From Amazon.com

Links:

SIRTF: Official site of California Institute of Technology
IRAC - Infrared Array Camera for SIRTF:
NASA Announces New Name for Space Infrared Telescope Facility:

References:

AstronomyNow Magazine, page 9, October 2003 edition.

Picture Source of SIRTF: NASA/JPL-Caltech (28/9/2003)
http://sirtf.caltech.edu/about/index.shtml