Mirror Lab expands with help of new crane

Charles C. Labenz Arizona Daily Wildcat As of yesterday, construction work is still underway, extending the Steward Observatory Mirror Laboratory underneath the east side of the UA football stadium. The construction has decreased the size of the Zone One parking area just outside the lab.

"It's a glorified shed for the crane," Warren Davison, the Mirror Lab's senior staff engineer, said of the addition on the east side of Arizona Stadium.

An additional 2,000 square feet will be added to the roughly 14,000 square feet currently occupied by the lab. The new space will serve as an assembly area and a loading dock for finished mirrors. Total cost for the expansion will be less than $1 million, Davison said.

"It's gone excellently," he said. "It's a little ahead of schedule."

The expansion began Jan. 5 and should be completed in mid-May, he said. The new $239,000 crane will be used to help assemble the mirrors and load them onto trucks bound for various mountaintop observatories.

"We are producing bigger and bigger mirrors," Davison said. "The logistics of moving them around have become harder and harder."

The lab dates back to 1980, when experiments were be conducted in Mirror Lab Director Roger Angel's garage. It was there that the technology for semi-hollow mirrors was born.

Angel was intrigued by the notion of using borosilicate glass - similar to the type used in glass ovenware - to make honeycombed structures.

When he successfully fused together a pair of pudding cups in an improvised kiln, he realized that the technology could eventually be used to produce mirrors larger and lighter than conventional solid mirrors. A series of larger kilns and furnaces soon led to the production of three 1.8-meter honeycomb mirrors.

With funding from the U.S. Air Force, the National Science Foundation and the University of Arizona, in 1985 Angel and his team established the new Mirror Lab under the east end of Arizona Stadium.

A rotating furnace was built inside the lab, and technicians soon began spin-casting mirrors as big as 3.5 meters in diameter.

The Mirror Lab's last major expansion was in 1990, when the furnace was enlarged to its current size and a new wing was added to house two mirror polishing stations and a test tower.

The lab's new two-story furnace was first used in 1992 to cast a 6.5 meter mirror, and in 1997 history was made with the successful casting of the first of two 8.4 meter borosilicate honeycomb mirrors - the world's largest - for the Large Binocular Telescope planned for the Mount Graham International Observatory.

Lab technicians began cleaning the first LBT mirror in early March.

"We're in the middle of (cleaning) it right now," Angel said. "So far it looks gorgeous."

Angel said the lab is now casting the last of three 6.5-meter mirrors. One is going into the Multiple Mirror Telescope on Mount Hopkins, and the other two are bound for the Magellan telescope near Santiago, Chile.

Upon completion of the 6.5-meter mirrors, technicians hope to begin casting the Large Binocular Telescope's second 8.4 meter mirror early next year, Angel said. Mirrors that size take roughly a year to cast and a year to polish before they are ready to be put into telescopes, he said.

"We just reached the point where there's so many of them to produce we get really backed up trying to move them around," Angel said. "This (the expansion) is a way to solve the problem."