BRUNSWICK, Maine — When the first-in-class USS Zumwalt sailed down the Kennebec River for the final time in September, onlookers flooded Popham Beach to watch as the futuristic stealth destroyer rounded the fort and headed into the Atlantic.

A small group of observers watched the departure with unique pride: Working from their company’s Brunswick facility, employees of Maritime Applied Physics Corp. had engineered two of the hundreds of technologically sophisticated systems on the new “stealth” destroyer, including safety barriers on the flight deck.

A third system designed by Maritime Applied Physics will be installed in the Zumwalt’s home port of San Diego.

“It was nine years of design, testing and producing something that had never been done before,” business development manager Richard Frost said. “It was gratifying to see the finished product doing what it was meant to do.”

Maritime Applied Physics was founded in 1986 by South Bristol native Mark Rice. The firm now works with the U.S. Navy, Air Force and Coast Guard and Northrup Grumman, among others.

Among the company’s more high-profile projects are a parasail fabricated in Baltimore that will carry radar, sensors and other communications equipment to be flown over a military ship to increase its line of sight from about 12 miles to about 33.5 miles, Popular Mechanics reported.

The Towed Airborne Lift of Naval Systems, or TALONS, was designed by the Defense Advanced Research Projects Agency, and demonstrated in October aboard a Navy unmanned surface vessel, the Anti-Submarine Warfare Continuous Trail Unmanned Vessel.

According to the defense agency, TALONS could carry intelligence, surveillance, reconnaissance and communications payloads of up to 150 pounds between 500 and 1,500 feet high.

In addition to systems for the Zumwalt class of destroyers, employees in the Brunswick facility fabricate the hull for the Greenough Advanced Rescue Craf), a multi-mission “Jet ski-like” vessel that U.S. Sen. Susan Collins ceremoniously — and carefully — christened with a ride in the Kennebec in July of 2012.

Workers in Brunswick also are developing a life-raft “pod” that can be dropped from helicopters, Frost said in January at the annual Maine Aquaculture R&D and Education Summit at the University of Maine.

While Brunswick is 10 minutes from Bath Iron Works, it’s also near much of Maine’s burgeoning aquaculture community, and Maritime Applied Physics has collaborated with groups on a number of projects including designing an automated system to flip oyster cages.

One project for Acadia Harvest focused on designing a self-sufficient, self-contained indoors growing space for four different marine species, according to Frost. Others focus on offshore aquaculture systems.

“You have to consider how you automate it if you’re trying to feed the fish that way,” he said recently. “What if there’s a hurricane? Do you submerge the whole system?”

“There’s a lot of long-term potential in Maine,” Frost said. “It’s growing, and we hope to grow along with it.”