By Lori Stiles

When astronomers turn the world's largest, most powerful telescope to the sky next year, they'll be on an Arizona mountaintop.

The Large Binocular Telescope (LBT) on Mount Graham is like no other telescope.

When completed in 2005, the LBT will have twin 8.4-meter (27-foot) primary mirrors on a single telescope mount. The "two-shooter" will have the light-collecting area of an 11.8-meter (39-foot) telescope. But what really excites astronomers is that the LBT will produce images as sharp as a 23-meter (75-foot) telescope would. That's 10 times sharper than images from the Hubble Space Telescope.

"The LBT isn't just the latest in the 8-meter generation of telescopes," LBT Corp. President Peter Strittmatter said. Strittmatter is director of the UA's Steward Observatory and head of its astronomy department. "With its 23-meter baseline, the LBT is the first of the next generation of very, very large telescopes. I believe it will signal the beginning of a new golden era in ground-based space exploration."

The first LBT mirror has been installed in the telescope, and technicians are testing intricate mirror support system hardware and software in preparation for telescope "first light." First light, or when the mirror collects its first celestial light, will be later this year.

UA astronomers Roger Angel and Nick Woolf conceived the basic LBT concept in the early 1980s, when U.S. astronomers were planning a 15-meter National New Technology Telescope (NNTT). Angel, Woolf, and engineer Warren Davison realized that an affordable, structurally strong two-shooter telescope would give astronomers unprecedented views of the universe. This binocular design ultimately became the LBT.

Collaborating institutions formed the Large Binocular Telescope Corp. that would build and operate the telescope in 1992, and construction began in 1996. New partners joined the consortium in 1997, ensuring completion of the full binocular telescope.

The University of Arizona, Arizona State University, and Northern Arizona University comprise a quarter partnership in the LBT project. Other partners include Ohio State University; the Research Corp.; the LBTB, a German consortium of astronomical research institutes; and the INAF, the Italian National Institute for Astrophysics. The Tucson-based Research Corp. supports Ohio State University, the University of Notre Dame, the University of Minnesota, and the University of Virginia in the project.

The Steward Observatory Mirror Lab, directed by Angel, has been developing new mirror technologies for the past two decades. The first LBT mirror was cast in the Mirror Lab's giant rotating furnace in 1997, then polished by the lab's unique stressed-lap technique to virtual perfection. The face of the deeply parabolic (F/1.14) mirror is so smooth that no place across the surface of the mirror varies by more than a millionth of an inch.

Italian engineers and scientists led by Piero Salinari of the Osservatorio Astrofisico di Arcetri made enormous contributions to the project. They took the LBT concept and designed the compact, stiff and innovative telescope. The telescope was built, fully assembled and tested at the Ansaldo-Camozzi Energy Special Components in Milan in 2001. It was then disassembled and shipped by freighter to Houston, Texas, and overland to Safford, Ariz., a small town at the foot of Mount Graham, the following year.

The 600-ton telescope was trucked to the mountaintop, reassembled and bolted to its 67-foot high, 53-foot diameter pier within the LBT enclosure in 2002. There's enough concrete in this architectural wonder to build 100 average size homes.

"Every time I go into the LBT building, I am amazed at how big the telescope is," Davison said. "I don't know anyone who knows the size better than I do, but I am amazed every single time I see it."

Researchers selected the Mount Graham International Observatory site in the Coronado National Forest near Safford years ago from a survey of 280 potential mountain sites in the continental United States. Mount Graham was chosen for its clear skies, low light pollution, low atmospheric water vapor, and ease of access.

Moving the first 18-ton LBT mirror ­ the world's largest single telescope mirror ­ to its 10,480-foot mountaintop in late October 2003 is a memorable chapter in LBT history.

The move was a two-stage, multi-day event that required five months of intense planning and preparation. Preparation included a trial run from the Mirror Lab in Tucson to the telescope on Emerald Peak with a "dummy mirror" in the mirror transport box in September.

Steward Observatory and Precision Heavy Haul, Inc. of Phoenix first hauled the 55-ton load of mirror inside its all-steel transport box over 122 miles of Interstate and state highway to the observatory's Safford base camp. A 25-vehicle police escort accompanied the mirror-carrying convoy for both traffic and mirror safety.

Then the team moved the boxed mirror up 8,000 feet over 29 miles of winding mountain road to the LBT, a three-day journey at speeds averaging one mile an hour.

"The move would not have been possible without the support of people in Graham County, the State of Arizona, Ohio, Italy, and Germany," Steward Observatory Associate Director Buddy Powell said at the time. "It is a perfect example of what people, with a wide and diverse background, can accomplish by working together."

After the first mirror was moved to the telescope structure late last year, engineering spent more than two months testing and perfecting mirror installation procedures using a dummy mirror in the actual mirror "cell," or mirror support structure. The mirror was then installed in the cell and, in precise operations that required maneuvering the mirror and cell through a hatchway between building floors with only inches to spare, LBT workers lifted the mirror onto the telescope structure in March.

The Mirror Lab is now polishing the second LBT mirror, which the lab cast in May 2000, to complete the $100 million binocular telescope.

How important is the LBT going to be to Arizona in the next decade or two?

"If Arizona is to remain at the forefront of ground-based astronomy, we'd better do it," Strittmatter said. "You don't stay ahead with little telescopes."