Engineer Jill Hruby was named director of the Sandia National Laboratories on Monday, becoming the first woman to head one of three U.S. government labs charged with developing and maintaining the country’s nuclear arsenal.

The 32-year veteran of the Albuquerque, New Mexico–based labs has overseen a wide range of research there, including studies focused on nuclear weapons, solar power, and machines that build miniscule electrical components the width of a human hair.

Hruby’s promotion is a significant milestone in a system historically dominated by men, says Hugh Gusterson, an anthropologist at the Institute for Advanced Study in Princeton, New Jersey, who has spent years examining the culture of the weapons labs: Sandia, the Los Alamos National Laboratory in New Mexico, and the Lawrence Livermore National Laboratory in California. At the labs, the fields of physics and engineering intersect with the world of weapons development—all traditionally male-dominated realms. “To have a female director is a major development,” Gusterson says.

Although Hruby acknowledged this first in a statement released by Sandia, she also emphasized the importance of the mission of the National Nuclear Security Administration (NNSA), the Department of Energy (DOE) agency that runs the weapons labs. “I’m proud to be the first woman to lead an NNSA laboratory, but mostly I’m proud to represent the people and work of this great lab,” she said.

Hruby will replace Paul Hommert, who is retiring from the post he held since 2010. She will be Sandia’s 14th director.

Hruby takes over at a time when Sandia enjoys a relatively stable position, observers say. It has avoided public missteps that have dogged its sibling labs. That includes delays and cost overruns at Livermore’s National Ignition Facility, which was built for nuclear fusion research. Los Alamos, meanwhile, has suffered from embarrassing security lapses and a 2014 radiation leak at a nuclear waste storage facility stemming from barrels originating from the lab.

Sandia’s workforce and budget have grown, as it takes a lead in the push to modernize the nation’s nuclear weapons. Today it has 10,800 workers and a $2.6 billion operating budget, compared with 6300 Livermore employees and 10,200 at Los Alamos. It has also proven adept at diversifying into other realms of research, with a significant slice of its budget (roughly a third in 2011 according to a Union of Concerned Scientists report) coming from work for other government agencies or private industry.

“It gets high marks relative to Livermore and Los Alamos in its annual assessment by DOE. It’s widely considered to be the best of the three in terms of management,” says Greg Mello, executive director of the Los Alamos Study Group, an Albuquerque-based nonprofit that promotes nuclear disarmament.

Still, Sandia has a lower profile than its more prestigious counterparts. Whereas Los Alamos and Livermore are home to physicists wrestling with knotty nuclear puzzles, Sandia is dominated by engineers designing the accompanying hardware, such as missile guidance systems.

Hruby comes to her job with decades of work as an engineer and manager. She has also spent little time in the public spotlight. Neither Gusterson nor Mello were familiar with her work, and few news articles mentioned her before Monday’s announcement.

But her track record drew praise from officials at Lockheed Martin, the defense industry giant whose subsidiary runs the Sandia labs through a contract with DOE.

“The board looked at a number of outstanding candidates,” said Rick Ambrose, chairman of the board of directors for Sandia Corp., the Lockheed subsidiary. “We saw right away that Jill has the right combination of technical expertise and strategic vision to lead Sandia into the future.

Before the promotion, which takes effect 17 July, Hruby was a vice president at Sandia overseeing work in “nuclear, biological and chemical security; homeland security; counterterrorism; and energy security,” according to Lockheed.

Hruby got her start at the lab’s California branch in 1983, shortly after she earned a master’s degree in mechanical engineering from the University of California, Berkeley. Since then, her research has covered fields including solar energy, nuclear weapon components, nanoscience, hydrogen storage, and microfluidics, according to Lockheed. She moved from California to the main New Mexico site in 2010. She currently sits on the National Academy of Sciences’ Board on Chemical Sciences and Technology.

Hruby has mentioned her unusual position as a woman in national lab management. In a 2013 issue of the Profiles in Diversity Journal, she was named to a list of “Company and Executive Women Worth Watching.” In an accompanying essay, Hruby wrote that for most of her career “I willingly expressed my opinions, but not my feelings. My behavior was driven by being different, since I was usually the only woman in my work group at my level, and did not want to accentuate the differences. I did laundry, cooked, worried about daycare, kids and getting homework done—and I kept it to myself.”

She noted that in recent years she learned that people wanted to know their leaders and she felt more comfortable talking about her experiences. “What is most important to me now is to create a work environment where all women and men can bring themselves more fully to work everyday,” she wrote.