On a bright, breezy day in New Jersey, a sharp buzz — something like a cross between a mosquito and a dentist drill — pierced the air, made by a drone performing a hairpin turn.

Andy Shen, sporting chunky white goggles, tinkered with a handheld device nearby. He was indulging a passion that he's managed to turn into a successful business.

Shen flew an in-house drone design called the "Krieger," a zippy quad copter unit. Racing lets the 51-year-old entrepreneur meet his customers, get immediate feedback, and test designs and refinements.

Shen is a drone frame designer and a participant in an emerging sport that combines aviation, technology, tinkering and gaming. In a booming market for privately owned drones, he caters to a specific segment with a company called Shendrones, which produces custom frames for professional drone racers.

In a field defined by camera drones like the DJI Phantom—and at a time when unmanned aerial vehicles (UAVs) are delivering packages, taking pictures and undertaking clandestine government operations—drone racing remains a niche. However, the FAA expects the commercial drone market to explode from 1.9 million in unit sales last year to 4.3 million by 2020. In a 2016 report, NPD Group said commercial drone sales skyrocketed by more than 200 percent from 2015.

Such bullish forecasts encourage converts like Shen, who believes the future of the sector is intertwined with the growing emphasis on science, technology, engineering and mathematics in education.

"A lot of STEM programs are looking to incorporate drones," Shen told CNBC. "Physics, aerodynamics, electronics, programming, there's just so much to learn from it."