It’s been more than half a century since George Jetson first left his Skypad apartment in Orbit City, hopped into his bubble-top aerocar and flew off to his job at Spacely Space Sprockets.
And ever since the animated series “The Jetsons” first aired in 1962, people have been waiting for that future to arrive. Especially the aerocar.
Now, advanced concepts engineers at NASA Langley Research Center in Hampton are gaining ground on futuristic technologies that could put people in their own personal air vehicles one day, as well as vastly improve general-aviation aircraft and even commercial delivery services using unmanned aerial systems.
The technology is called distributed electric propulsion, which basically means using lots of very compact, very redundant, highly efficient, electrically driven propellers to power vehicles in flight, as well as in vertical take-off and landing.
The technology could be available in the near-term in general-aviation aircraft that make short hops of less than 200 miles or so, and in the longer-term for smaller, personal vehicles.
“We have an effort we’re doing this year with an automotive company to look at what we call hyper-commuter personal air vehicles,” said engineer Mark D. Moore. “This is the Holy Grail of what people have been talking about for a hundred years. This is flying cars. And you really would be somewhat insane to be talking about doing it if you didn’t have the new technologies that were changing what you could do with these vehicles.”
The new technologies aren’t all available quite yet, but NASA has put $250,000 into a “seedling” effort to explore some of them, he said, with a matching amount from the automotive company, which he said he couldn’t name.
And the agency is partnering with Empirical Systems Aerospace, or ESAero, and Joby Aviation on a wing demonstration project. They began in January and have built a 31-foot, electric-powered wing fitted with an array of small propellers distributed along its leading edge. And in two weeks, Moore said, they’ll be testing it in a dry lakebed near NASA’s Armstrong Flight Research Center in Edwards, Calif. Armstrong used to be known as Dryden.
“So in less than a year, we will have concrete data that shows just how effective this is,” Moore says.
‘Golden Age of aeronautics’
Moore’s enthusiasm for his work was palpable as he peppered a recent briefing on his research with words like “neat,” “really cool” and “incredible.”
“When you’re on a technology frontier, it’s a great place to be,” he said. His colleague, research engineer Ken Goodrich, agreed. “It’s another Golden Age of aeronautics, I think,” Goodrich said.
Not that there aren’t challenges. Battery technology, for instance, hasn’t caught up with the vision — they’re still too heavy, expensive and can’t hold a charge long enough to make long distances feasible.
But the technology is improving every year, they said, and by 2025 batteries could be efficient enough to handle flights of up to 300 miles.
“I don’t want to be misleading,” Moore cautioned. “Electric propulsion is not going to be flying us across the country any time soon. Commercial aviation does a great job of doing that. What we’re interested in is being able to do regional travel and on-demand type of travel that’s shorter distance (and) be able to open up completely new aviation markets that are very, very appropriate for electric propulsion.”
They’re also working with the Federal Aviation Administration to certify the new technology under a new, fast-track “consensus standard” the FAA is developing. If all goes well, Moore said, commercial commuter aircraft could be using distributed electric propulsion in five to seven years.
What’s also “really cool,” he said, is that automaker BMW has come out with an electric car built with an all-carbon-fiber body. Carbon fiber composites have been used for years to make aircraft because they’re stronger than steel yet lightweight. But while a carbon fiber aircraft can cost about $700,000, he said, BMW’s i3 is selling for about $40,000.
“Even three years ago if you’d said that somebody was going to make an all-carbon fiber structure and sell it for $40,000, you’d have said, ‘That’s insane,'” Moore said.
Bloomberg Businessweek reported last year BMW was able to curb expenses by taking the unusual step of making the carbon fiber itself rather than outsource the manufacture.
There’s also flexibility built into the low cost, Moore said, since carbon-fiber structures are built by robotic systems laying down layer after layer of filament.
“You can apply these automotive technologies — even if we’re only making 1,000 or 2,000 aircraft per year — and still achieve a 10-times reduction in the cost of those panels versus aerospace practices,” Moore said. “And it’s the same quality, the same lightweightness. So there’s this wonderful convergence that’s happening between automotive technologies and aerospace technologies where we can leverage what each other is doing to make this vehicle a $50,000 vehicle.”
‘Big, big changes’
The lure of distributed electric propulsion is that the motors are far more efficient, less polluting, much quieter and lighter than fossil-fueled piston engines, Moore said. Each propeller has its own electric motor and control — a redundancy that builds safety into the system should a motor fail.
And it’s a scale-free technology, so smaller versions are just as good. This would make them affordable, safer alternatives to current versions being considered for small drone technologies to deliver packages.
“It doesn’t matter if it’s a 300-horsepower motor or a 3-horsepower motor — we still get the same efficiency and the same power to weight ratio,” Moore said.
Engines can be distributed around the vehicle to achieve a variety of things: for optimal control, for optimal weight distribution, for the lowest weight structure and the lowest drag, he said.
Propellers mounted along the leading edge of the plane’s wing accelerate the airflow, which means the wing area can be reduced in a small aircraft for lower drag and a better ride.
The result, as one unmanned test flight demonstrated, is robust control, “incredible stability” and a “rock-solid hover,” he said.
“It’s not incremental differences,” Moore said. “That’s what’s so exciting about this. It’s big, big changes that are being enabled by these new technologies.”
David E. Bowles, deputy director of NASA Langley, said “on-demand mobility”
— a phrase that covers using aviation systems for a range of personal uses
— is built into NASA’s 2014 strategic plan as one of its aeronautics goals.
“It means a lot to the whole air transportation system,” Bowles said. Within three years, Moore said, they expect to have a vehicle ready for what could be the first manned test flight of a distributed electric propulsion vehicle.
“It’s fundamentally going to change what we can do and what we’ve wanted to do for so long in aviation,” Moore said. “And it’s not going to be that far away.”