WASHINGTON — The aerospace and defense sector is bracing for a potential brain drain over the next decade as a generation of Cold War scientists and engineers hits retirement age and not enough qualified young Americans seek to take their place.

The problem — almost 60 percent of U.S. aerospace workers in 2007 were 45 or older — could affect national security and even close the door on commercial products that start out as military technology, industry officials said.

While U.S. universities are awarding 2 1/2 times more engineering, math and computer science degrees than they did 40 years ago, defense companies must compete with the likes of Google, Microsoft and Verizon for the best and the brightest.

"It's about choices," said Rich Hartnett, director of global staffing at Boeing Co. "There are so many more options today with a proliferation in the kinds of degrees and career paths that people can follow."

Industry leaders are doing their best to emphasize the allure, and growing importance, of jobs linked to national defense.

Aerospace Industries Association Chief Executive Marion Blakey said the U.S. could be facing another "wake-up call," similar to the 1957 Soviet launch of Sputnik, the world's first satellite. China's success in shooting down one of its own satellites last year, as well as the upcoming retirement of the U.S. space shuttle fleet, signal that the country cannot afford to take its technological and military superiority for granted, said Blakey, the former head of the Federal Aviation Administration.

CURBS ON FOREIGNERS

In addition to fierce competition for a limited pool of math and science experts from all corners of corporate America, contractors working on classified government programs are hamstrung by another factor: restrictions on hiring foreigners or off-shoring work to other countries.

"The ability to attract and retain individuals with technical skills is a lifeblood issue for us," said Ian Ziskin, corporate vice president and chief human resources and administrative officer for Los Angeles-based Northrop Grumman Corp.

Ziskin estimates that roughly half of Northrop Grumman's 122,000 workers will be eligible to retire in the next five to 10 years. The trend is the same at Lockheed Martin Corp., of Bethesda, Md., which could lose up to half its workforce of 140,000 to retirement over the next decade. At Chicago-based Boeing, about 15 percent of the company's engineers are 55 or older and eligible to retire now.

The launch of Sputnik set off panic that the U.S. was falling behind in the space race. And it swelled the ranks of aerospace and defense workers as a wave of Americans answered a call to help the U.S. regain military superiority and began careers building rocket ships and missiles.

GRADUATES WOOED

Fifty years later, industry executives fear there won't be enough new defense sector workers to replace those employees as they retire.

In 2005, U.S. universities awarded 196,797 undergraduate and graduate degrees in engineering, math and computer science, according to the Commission on Professionals in Science and Technology. That's up sharply from 77,790 degrees in 1966. But competition for those graduates is more intense than ever.

Defense companies today are competing with Google Inc. and Microsoft Corp. — not to mention Wal-Mart Stores Inc. and the Navy — for computer science majors, according to Kimberly Ware, associate director for employer relations at Virginia Tech. They are vying with General Electric Co., Westinghouse Electric Corp. and the big automakers for electrical and mechanical engineering graduates, she said.

For its part, Boeing is up against telecom giants such as Verizon Communications Inc. and Sprint Nextel Corp. as it grows its satellite business. It even competes with video game makers such as Electronic Arts Inc. for 3D graphic designers and software programmers.

At the same time, defense executives acknowledge, the sector does not exert the same patriot pull as it once did since young people today have never known a time when the U.S. was not a leader in space exploration or the world's sole superpower.

NO OUTSOURCING

The industry confronts another challenge, too. Unlike technology companies, defense companies generally have to hire American citizens since they need employees who can obtain security clearance. This eliminates foreign graduates of American universities and foreign employees in the U.S. on H-1B visas.

"The talent is going to have to be homegrown," said Blakey of the aerospace association.

Similarly, defense contractors cannot outsource to countries with more technical workers, such as India or China.

Against this backdrop, defense companies are reaching out to American students in the earliest grades.

Lockheed Martin is sending employees into elementary schools to tutor students in math and science and is recruiting high school students to shadow Lockheed workers on the job. The company's engineers coach robotics teams, conduct rocket propulsion experiments for students and participate in mentoring programs.

Northrop Grumman has established a program called Weightless Flights of Discovery, which allows middle school teachers to experience temporary weightlessness on "zero-gravity" airplane flights that mimic how astronauts train for space travel.

Defense contractors are also trying to market themselves to job candidates with flexible schedules, tuition reimbursement programs and plenty of opportunities for advancement. Above all, noted Linda Olin-Weiss, director of staffing services at Lockheed Martin, the defense industry offers "challenging work on programs of national importance."

The implications of falling behind extend beyond national security since military technology often has civilian uses, too. The origins of GPS satellites and the Internet are linked to military applications.

But with the U.S. space program planning a return to the moon and a manned mission to Mars, Blakey believes there is at least one event on the horizon that could lure a new generation of Americans into the aerospace and defense industry.

"The question is: How do you encourage young kids to think of themselves as potential scientists and engineers?" Blakey said. "We hope that a return to the moon and Mars will help inspire them."