As a kid, Carl Dietrich ‘99, SM ‘03, logged countless hours designing spaceships with his Fisher-Price Construx plastic building set. These days he’s working on a flying car with wings that fold up for on-road travel. “I’ve been thinking about flying cars and such since almost as long as I can remember,” he says. “I was one of those kids who knew I was going to be an aerospace engineer from the age of eight, when I started saving to get my pilot’s license.”

But Dietrich’s personal air vehicle is just one of a long string of inventions, an impressively broad portfolio that earned the 29-year-old aero and astro doctoral candidate this year’s Lemelson-MIT Student Prize for Inventiveness.

As an undergrad at MIT, Dietrich cofounded the MIT Rocket Team after hitting on the idea of a centrifugal direct-injection engine to lower the cost of space access. He now holds a patent for his low-cost, high-performance rocket propulsion engine, which operates without a conventional turbo-pump pressurization system.

A research internship at Los Alamos National Laboratory led Dietrich to come up with a patent-pending efficiency-improving design for a desktop-size Penning fusion reactor. Because these reactors, which have millimeter-scale reactor cores, could be strung together to increase capacity, Dietrich says they may one day enable distributed fusion power.

Dietrich’s list of inventions also includes the PickProd, a blast-safe demining pick for removing landmines from hard-packed earth that he invented after taking a humanitarian demining course taught by Andrew Heafitz ‘91, SM ‘01, a fellow Lemelson-MIT Prize winner. Dietrich purposely didn’t patent the low-cost device, which he jokingly refers to as a gardening tool, so that it could be copied and used wherever it’s needed. A U.N. demining specialist is now blast-testing the PickProd.

For his doctoral work, Dietrich is researching a type of fusion reactor that uses electric rather than magnetic fields. Without heavy magnets, the reactor would be lightweight enough for spacecraft power and propulsion. Yet he’s also finding time to launch Terrafugia, a startup company that will build and sell Transition, his personal air vehicle.

The vehicle is designed to let travelers with sport pilot’s licenses avoid commercial airlines or long drives and tap into a network of more than 5,000 small airports to cut down on travel time for trips of 100 to 500 miles.

Using premium unleaded gas, Transition will be able to fly at 120 miles per hour with better fuel economy than most cars, Dietrich says. And with its wings folded, the SUV-sized vehicle will fit in most garages. Among the patents pending for the Transition design are those for its aerodynamic bumpers that bounce back to their original shape after impacts and an RFID system for rapid access to local airports.

Dietrich is using part of the $30,000 Lemelson-MIT Prize to build a one-fifth scale mock-up of Transition in the basement of Building 33. He’ll test it in the Wright Brothers Wind Tunnel and take it to the Experimental Aircraft Association’s AirVenture convention this summer in Oshkosh, WI. If he gets enough refundable orders, he’ll seek funding to build a full-scale prototype.

Although he watched The Jetsons as a kid, Dietrich insists that the show didn’t inspire him to design Transition. “The Jetsons were always a little too far off,” he says. “Despite the fact that I’m working on a flying car, I’ve always been a pretty practical guy.”