Infrared astronomy at Cornell: 40 years of peering deep into the universe's young, dirty and frigid regions
By Susan Lang
"Infrared astronomy has revolutionized and transformed the way we view the makings of the universe and our place in it. The advantage of infrared radiation is that it can be detected from deep within distant, dust-shrouded regions that are impenetrable to visible light. Infrared observations now reveal the physical processes which took place in the formation of galaxies and stars billions of years ago," said Martin Harwit, Cornell professor emeritus of astronomy and infrared (IR) astronomy pioneer, in 1999.
The United States' most prolific group in developing IR astronomy, Harwit has written, "may well have been the Cornell University infrared astronomy group, where space infrared astronomy was the goal right from the start."
Partly due to Cornell-led research, it is now known that there are distant galaxies emitting up to 50 times more energy at far IR wavelengths than in the optical domain, while also emitting from 100 to 1,000 times as much total power as our own galaxy, the Milky Way. To exploit this powerful discovery, SIRTF, the Space Infrared Telescope Facility, will be launched Aug. 23 to circle the sun in an orbit trailing behind the Earth and chart the IR universe. It is the largest IR telescope to be sent into space and is the last of NASA's four great observatories.
Cornell has played a major role in the development of SIRTF; it has been responsible for the design and development of the infrared spectrograph (IRS), one of the telescope's three science instruments, under the direction of principal investigator James Houck, the Kenneth A. Wallace Professor of Astronomy. The IRS, Houck says, can penetrate obscuring dust in the dirtiest parts of the cosmos and observe ultrafrigid, newly forming stars in the coldest regions of the universe.
Cornell has a long history of working with NASA's Jet Propulsion Laboratory and Ames Research Center in developing IR astronomy. Here are some of the highlights of those collaborations.
1963, IR astronomy research begins at Cornell
In 1963 Harwit inaugurated a U.S. Naval Research Laboratory/Cornell IR research program. In 1964 he obtained a NASA grant to continue his research at Cornell. Houck joined the group as a postdoctoral researcher. Several years of intensive engineering to design and build a liquid helium-cooled telescope for a successful astronomical flight ensued.
First successes: Cornell sends IR instruments into Earth's ionosphere
In 1970 Harwit's group sent an IR detector into space, discovering and accurately measuring IR radiation emitted by the circumsolar zodiacal dust cloud. In 1971 a Cornell liquid helium-cooled telescope discovered the magnitude of the total IR flux emanating from the galactic center and four other regions in central portions of the Milky Way.
1976, IRAS, the Infrared Astronomical Satellite, is funded by NASA
Houck becomes a leading member of the science team developing the science instruments for NASA's first IR telescope to conduct an all-sky survey of the mid- and far-IR wavelengths.
1976-77, Houck and colleagues begin promoting a large IR telescope
After IR experiments with NASA planes, Houck and his colleagues urge NASA to launch a major IR telescope into space. Their effort is rewarded in 1984 with the beginning of the SIRTF program.
1983, IRAS is launched and is a spectacular success
Houck plays a key role in analyzing data showing the existence of ultraluminous infrared galaxies emitting up to 50 times more energy at far IR wavelengths than in the optical domain, while also emitting from 100 to 1,000 times as much total power as the Milky Way. Most of these galaxies, it is found, are on a collision course with each other. During its 300-day lifetime, IRAS dramatically changes scientists' perspectives on the universe and increases the number of known IR galaxies from 25 to 250,000.
1984, Cornell is chosen to build SIRTF's IRS
Houck leads the team that wins the NASA award to build the observatory's IR spectrograph.
1992, SpectroCam-10 instrument developed at Cornell
The SpectroCam-10, an IR camera/spectrograph for astronomical observations in the 10-micron wavelength band, is built by Cornell astronomers for use on the 200-inch Hale telescope at California's Palomar Observatory. The SpectroCam-10 collects infrared images and spectra of astronomical objects from nearby planets and comets to distant galaxies.
1997, Cornell receives award to build IR camera for airborne astronomy
Terry Herter, Cornell professor of astronomy, receives a $2.1 million NASA award to develop and build FORCAST (the Faint Object infraRed Camera) for the airborne telescope,SOFIA the (Stratospheric Observatory for Infrared Astronomy).. FORCAST will be among the main instruments on the space agency's Boeing 747-based airborne observatory when it takes off in 2004. Gordon Stacey, associate professor in astronomy (now professor), and George Gull, senior research support specialist in radiophysics and space research, also are on the team.
1997, Cornell receives NASA funding to build IRS
Houck contracts with Ball Aerospace Corporation of Boulder, Colo., to build the IRS.
1998, SCORE instrument developed at Cornell
Houck and associates build SCORE (SIRTF Cornell Echelle), a mid-IR spectrograph designed to operate properly upon assembly needing nothing more than a one-time focus adjustment, as a proof-of-concept demonstration for the IRS. SCORE is successfully used on the Palomar 200-inch Hale telescope to collect data for several Ph.D. theses.
1999, Cornell helps build the Wide Field Infrared Explorer (WIRE)
Cornell plays a key role in building WIRE, a NASA-funded mission to study the evolution of galaxies. Its mission ends shortly after launch when a critical cover plate is released prematurely, causing the satellite to spin out of control and the frozen hydrogen within to evaporate much too quickly. Although the satellite is now functioning, the IR detectors are crippled by the loss of the hydrogen.
2003, After delays, SIRTF is launched
After a delay lasting several months, SIRTF is launched on Aug. 25 aboard a Delta II Heavy rocket.
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