UA hopes to shine in mirror race

Ian Mayer Arizona Daily Wildcat Richard W. Wortley, president of Hextek, observes the 2.5 meter generator aligning for glass generating yesterday afternoon at Hextek. Wortley is part of a team all trying to build the best light-weight mirror for the Next Generation Space Telescope. NASA will judge which of the three teams can best produce a, 8-meter mirror for $60 million.

The University of Arizona is in a contest to develop a light-weight, 8-meter mirror for the Next Generation Space Telescope.

The university's mirror lab will go up against San Diego-based Composite Optics, Inc. and Ball Aerospace Corp. in Colorado.

NASA will decide which team vying for the $60 million project creates the best mirror by 2002.

The slated launch date for the telescope, which will orbit the sun at minus 396 degrees Fahrenheit, is in 2007.

"This will allow scientists to answer many questions about evolution of galaxies, the size of the universe and the history of the solar system," said Doug Neam, program manager of Ball Aerospace.

"It will be able to investigate- galaxies that were barely detected by HST (Hubble Space Telescope)," Neam said.

The $500 million Next Generation Space Telescope costs one-fourth less than the Hubble Space Telescope. The new telescope will have 10 times more light gathering capability and will be able to see infrared wavelengths.

The infrared telescope will allow scientists to study faint objects in detail, Neam said.

The mirror project, capped at 1,600 pounds, must squeeze into a 5-meter spacecraft opening.

The UA's mirror is still in the design phase, said James Burge, assistant optical sciences professor. The UA team is configuring the mirror to be more light-weight than past mirrors.

"The principle difficulty is (that) it has to be lighter," Burge said. "We have to make it thin - it's 2 millimeters thick."

Burge said keeping the UA mirror's surface smooth also poses a challenge. It is unique because it has an actuator, a motion-control device that shapes the mirror, Burge said.

A one-dimensional robot pushes the glass in and out until it becomes a continuous surface to focus on an image, he said.

"The telescope points at a bright star and adjusts until it gets a good image," Burge said.

He said the process provides rigidity to the mirror, which would loose focus of an image without a stable support structure. Scientists must actively correct the actuator by adjusting the measurements.

The UA's other unique resource is adaptive optics, which is "the ability to make large mirrors with steep curves," Burge said. It brings the focus of the light closer to the mirror, creating a clearer picture.

NASA gave the UA $5 million to build the prototype, which UA scientist said will be done on time.

Kelly Dodson, program manager for Composite Optics, Inc. said his company's mirror uses a simpler design than the UA's.

Still, the UA team thinks its mirror will shine above the rest.

"We have good technical interest and engineers who are very motivated," Burge said.

Irene Hsiao can be reached via e-mail at Irene.Hsiao@wildcat.arizona.edu.