As far back as he can remember, Craig Nance has loved two things: astronomy and electronics. So as the facility engineer for the world's largest optical/infrared telescopes, he is a happy man indeed. The fact that the telescopes, known as the W.M. Keck Observatory, happen to be in one of the loveliest places on the planet, namely on the Big Island of Hawaii, just seems like overkill.

This engineer does work hard. At the office by 7 a.m. most days, Nance is never quite sure what the day will throw his way. Install a dye-laser system to help correct for atmospheric distortion to incoming starlight? Figure out how to run a ground wire into arid rocky terrain at 4200 meters above sea level? Damp vibrations from dozens of machines and industrial motors along an 85-meter path? Nance has worked on all that and more.

Though Nance points out that every project at the observatory is a team effort, that he's just "doing what needs to get done," a quick glance at the dozen or so to-do lists scribbled on his office whiteboard says otherwise. As he talks about the variety of problems he's been called in to fix, you quickly get the sense that Nance is the go-to guy at Keck.

As a boy in Jacksonville, Fla., he built his own telescopes from scratch and was an avid backyard sky watcher. When he couldn't decide between the college-preparatory track in high school or electronics repair in vocational school, he took both, even though it meant giving up his summers.

At Florida State University, in Tallahassee, electrical engineering was a natural fit. After getting his BSEE in 1991 and an MSEE in 1994, Nance's next stop was the U.S. Air Force. From 1994 to 1997, he served as a commissioned officer at the Arnold Engineering Development Center, a huge testing facility near Tullahoma, Tenn. The experience "taught me to be an engineer and to work on large machinery," Nance recalls. What he didn't like was being "one little cog in a big machine. If I stayed, I could see myself becoming the world's leading expert in one very tiny area. That seemed terribly boring."

With the end of the Cold War and the downsizing of the military, Nance got the nudge he needed. One day, an older engineer took him aside and told him to "figure out what you really want to do." Nance replied that he'd always liked astronomy but didn't have the right degree. "Don't worry about that," his friend said. Everyone needs engineers.

Though Nance wasn't completely convinced, he thought he'd take a shot at "the brass ring." While scanning an online job listing hosted by the IEEE, he spotted an opening that seemed tailor-made. A new advanced optical telescope in Texas needed an electrical engineer. Nance applied for and got the job, and soon found himself in the Davis Mountains of West Texas, at the McDonald Observatory. By 1999, he was the observatory's facilities manager.

In 2000, he made the move to Keck, which was like landing on cloud nine—literally. Keck sits atop Mauna Kea, a dormant volcano that shoots up more than 4 kilometers above sea level. Trade winds sweep the summit free of clouds, making it an ideal spot for stargazing. Reachable only by a 2-hour, bone-jarring drive along loose gravel switchbacks, it's a precarious place to work—it towers above 40 percent of the Earth's atmosphere, and unaccustomed visitors can grow lightheaded. For those reasons, the observatory's administrative office is in Waimea, a small town at the volcano's base. "I do my thinking back at headquarters before heading up to the summit to work," Nance says.

Every Monday starts with a staff meeting to run down upcoming observations, repairs, maintenance, and the like. Astronomers vie for observing time on Keck, so they fully expect everything to work properly when they show up. "Some nights the weather doesn't allow us [to work], sometimes the moon is a factor, but we never want to lose a pristine night because something breaks," Nance says. That's a tall order, given that Keck is a unique machine—its instruments are mostly custom built and require constant care.

Keck, operated by the California Institute of Technology, the University of California, and NASA, shares Mauna Kea with 12 other observatories, but it's by far the largest and most complex. The sensitivity of any telescope depends in great part on the size of its primary mirror. But there are physical limits to how big you can make a single mirror. Keck gets around that by using segmented mirrors. Computer-controlled sensors and actuators on each of the 36 hexagonal segments continually make fine adjustments, down to 4 nanometers, so that the segments work as if they were one giant mirror 10 meters across.

A constant thrill for Nance is rubbing elbows with the biggest names in astronomy and getting an insider's preview of their news-making discoveries—planets beyond our solar system, stars being consumed by the black hole at the galaxy's center, storms raging on Uranus.

He doesn't even mind that the scientists get all the glory. He sees himself as part of a long tradition of engineers in astronomy. On his desk sits a photo of Russell Porter, the legendary telescope designer who played a pivotal role in the birth of California's Palomar Observatory—an engineer, like Nance.

"If I won the lottery tomorrow," he says, "I'd still do pretty much what I'm doing now."