Star Search - The Real Thing

A rocket carrying the largest diameter infrared telescope ever put into space roared from its seaside pad early Monday.

The Space Infrared Telescope Facility, known as SIRTF, is the last of four NASA spacecraft designed to peer deeper into the universe using an array of tools that measure light of varying wavelengths.

The telescope will add to the work of the Hubble Telescope, launched in 1990, the Chandra X-ray Observatory, launched in 1999, and the Compton Gamma-Ray Observatory, which operated for nine years before falling back into Earth's atmosphere in 2000.

The telescope will look at some of the same deep space objects as its sister craft in order to make comparisons between the views. It will also survey other parts of the cosmos.

The 110-pound, 33.5-inch telescope is designed to measure heat from faraway celestial objects and give scientists a view of distant solar systems being born.

"Stars are continuing to form in our own galaxy," said Dr. Michael Jura, SIRTF interdisciplinary scientist for planetary science at the University of California at Los Angeles. "One of the main scientific goals of SIRTF, I think, is to develop a much better understanding of how stars and planets form."

The spacecraft will conduct its work from an Earth-trailing orbit around the sun that will allow the telescope to avoid the interference caused by Earth's infrared-absorbing atmosphere. After separating from the rocket's upper stage, the spacecraft will fall in line behind the Earth as it circles the sun.

"SIRTF will be following the Earth around the sun, kind of like a faithful puppy dog," said Dr. Michael Werner, SIRTF project scientist at NASA's Jet Propulsion Laboratory.

The launch is a long-awaited triumph for SIRTF scientists. The project was originally proposed in the mid-1970's but was repeatedly cut back and delayed.

The mission is scheduled to last at least 30 months, but could be extended. Mission project manager David Gallagher said the total mission cost is about $1.19 billion.

The first images from the telescope are expected to be available to scientists in late October and are to be released to the public in December.

The spacecraft was launched into orbit atop a Boeing Delta II Heavy rocket.

The SIRTF spacecraft contains three instruments to record the light collected by the telescope: an infrared array camera, an infrared spectrograph and multiband imaging photometer.

Because they measure heat, the instruments will allow the telescope to see through clouds of dust and debris that other telescopes cannot penetrate. Scientists say the infrared sensitivity will allow astronomers to study the most distant, coldest and most dust-obscured objects and processes in the universe.

"We're really looking for that which is unseen," Gallagher said. "It's a little like peering into a dark room and turning on the light."