HUNTSVILLE, Alabama - Dr. James Hadaway and his colleagues "knew something bad was happening outside" their Marshall Space Flight Center test chamber on April 27, "but we had to focus on what we were doing."

Good idea. Hadaway was taking measurements of gold-coated mirrors built for NASA's James Webb Space Telescope. The mirrors were inside a Marshall test chamber at 378 degrees Fahrenheit below zero.

Outside, the area was being battered by a storm system that ultimately spawned 62 tornadoes and knocked power out across Madison County.

Hadaway and his colleagues from the University of Alabama in Huntsville finished their measurements and went home at 5:30 p.m. Moments later, the power went out to the X-ray and Cryogenic Facility (XRCF) where the tests were held.

"Fortunately, the XRCF has a diesel generator," Hadaway said in a recent interview published on the UAHuntsville website. "That night they emailed us, 'We're still good.' "

It was good. The Webb mirrors are essentially priceless, and they are supposed to cycle between extreme cold and normal temperatures over several days. Bringing them from deep freeze to room temperature quickly might have ruined much more than one experiment.

"The real story is the people who run the facility," Hadaway said in the interview. "They're the ones who did the heroic job, arranging for enough diesel fuel, liquid nitrogen, liquid helium and all the other things to keep us running."

The six mirrors tested in April were the first of 18 being tested at Marshall this year. The second set of six are at the XRCF now.

Hadaway, a principal research scientist for UAH's Center for Applied Optics, has been part of the Hubble team from the start, working with colleague Dr. Patrick Reardon. It was Hadaway's idea to use Marshall Space Flight Center to expose the mirrors to extreme conditions to make sure they will be smooth and focused in deep space.

When the Webb telescope was first proposed, no one knew how mirrors built on Earth would perform in the extreme cold of space. During a meeting at Marshall, someone asked if there was a way to test them first.

"We can do that," Hadaway said in the interview.

Hadaway had helped NASA develop specialized mirrors for X-ray telescopes such as the Chandra X-ray Observatory. He was pretty sure the team could develop the tools to test Webb's mirrors, too.

Using the house-sized XRCF, the test team basically cools the mirrors to space temperatures and measures their distortion.

"We send what we find to Tinsley Laboratories in Richmond, Calif., which polishes opposite distortions into the mirrors," Hadaway said. "If it was a bump when it was cold, they polish in a hole. Now, it looks bad at room temperatures, but it's perfect in the cold."

Hadaway said the average imperfection allowed is the height of 200 hydrogen atoms.

In the 15 years he has been involved with Webb, Hadaway's team has received more than $5 million NASA funding for its mirror work.

"I was part of this program from day one," Hadaway said. "My goal is to be there when it's in orbit and certified to be operational."