http://www.nytimes.com/2008/07/29/science/29jetpack.html?_r=1&ref=science&oref=slogin
The Jetpack: From Comics to a Liftoff in the Yard
OSHKOSH, Wis. — To rise off the ground wearing a jetpack is to feel the force of dreams. Very, very noisy dreams.
On Tuesday, an inventor from New Zealand unveiled what he calls “the world’s first practical jetpack” at the EAA AirVenture, the gigantic annual air show here. The inventor, Glenn Martin, 48, who has spent 27 years developing the devices, said he hoped to begin selling them next year for $100,000 apiece.
“There is nothing that even comes close to the dream that the jetpack allows you to achieve,” said Robert J. Thompson, the director of the Bleier Center for Television and Popular Culture at Syracuse University. He called it “about the coolest desire left to mankind.”
For Mr. Martin, the jetpack is the culmination of a dream that began as a 5-year-old in Dunedin, New Zealand. For those who still remember childhood dreams of flying and comic-book visions of the 21st century, the jetpack suggests the possible fulfillment of the yearning for those long-promised gifts of technology.
Buck Rogers and James Bond used jetpacks, and since the 1960s, several real jetpack designs have been built from metal, plastic and propellant. None has flown more than a minute. Mr. Martin’s machines can run for 30 minutes.
At first sight, parked in the back of the U-Haul van Mr. Martin used to cart it to the air show, it did not look like the classic jetpacks of science fiction. It stands about five feet tall and its rotors are encased in two large ducts that look a bit like cupcakes. It rests on three legs. Mr. Martin has somehow made the future look both sleek and nerdy.
“If someone says, ‘I’m not going to buy a jetpack until it’s the size of my high school backpack and has a turbine engine in it,’ that’s fine,” he said. “ But they’re not going to be flying a jetpack in their lifetime.”
It is also not, to put it bluntly, a jet. “If you’re very pedantic,” Mr. Martin acknowledged, a gasoline-powered piston engine runs the large rotors. Jet Skis, he pointed out, are not jets, and the atmospheric jet stream is not created by engines. “This thing flies on a jet of air,” he said. Or, more simply, it flies.
On a couple of test runs in the yard of a home here belonging to a friend of Mr. Martin, the jetpack jumped off the ground as if impatient to get moving, scattering a cloud of dirt and grass clippings.
With the startling power of its twin rotors and its 200-horsepower engine behind my shoulder blades screaming like an army of leaf blowers, it felt almost as if I were doing the lifting myself, with muscles I did not know I had. It felt like living in the future — and, even better, the future we imagined back when it was something to be hoped for rather than feared.
Pressing the left-hand stick forward caused the device to pitch forward slightly, and the jetpack began advancing, a few feet above the lawn. Mr. Martin and a colleague steadied it by grasping hand rails and trotting alongside, like parents teaching a child to ride a bicycle without training wheels.
Then, coming around a curve, Mr. Martin jogged to the right to avoid some equipment on the ground, bringing the jetpack too close to an overhanging tree. The limb was sucked into the rotors with a brief but sickening sound, like a blender trying to make a margarita with twigs. Luckily, he had spare parts and access to a workshop to replace a chipped rotor.
Mr. Martin started trying to make his jetpack dreams come true in college. While he was studying biochemistry, he was also working on painstaking calculations of thrust in the library and researching the Wright brothers’ methodical approach to technology development. He later had jobs in the pharmaceutical and biotechnology industries, but much of the money went to the work going on in his garage. He built a network of enthusiasts who helped him develop his ideas.
In June 1997, seven weeks after the birth of his second child, Mr. Martin figured his prototype was now powerful enough to lift its first flier, so long as that person weighed less than 130 pounds. So he turned to his wife. “I said, ‘Hey, Vanessa, what are you doing tonight?’ ”
Mrs. Martin agreed to be her husband’s levitating guinea pig. Mr. Martin yoked the unit to a pole in the garage so it would lift her without moving around, put a kind of brake at the top of the pole in case the engine was stronger than he thought, and strapped her in.
She admits now that, deep down, she was not sure she would take off. At the same time, she was “very scared” of the device she calls “the beast.”
The engine fired up, sounding angry, she said, and the air started blasting around her. “There’s a moment when it will just bite,” she said, and seem to grab the air and go. “That was it,” she said. “I was totally addicted.”
She said she felt, in a way, that she had conquered it — “the taming of it, that’s so exciting.” It was, she said, “probably the best experience of my life.”
To prove that anyone could learn to use a later prototype, Mr. Martin also enlisted his son Harrison, then 15, as a test pilot. Too young to drive, he learned to fly. The family’s need for secrecy until the project could be patented and properly announced meant that Harrison could not tell his friends about it.
“I can’t think of a better secret,” he said, but added that it was not a hard one to keep. “Basically, for my whole life I’ve had a jetpack in the garage,” said Harrison, now 16, with a shrug, “so it’s just one of those things you don’t talk about.”
With a working engine and video in hand, Mr. Martin was able to start raising enough money to quit his day job and devote himself to jetpack development full time. Before long he had venture capital financing and a PowerPoint presentation.
The current iteration of the product, the 11th, weighs about 250 pounds and provides 600 pounds of thrust. It includes safety features like a so-called ballistic parachute with a small explosive charge for rapid deployment in case of an emergency, like those used in some small airplanes.
The pedestal that forms the main support for the device has a shock absorber like a pogo stick to soften landings. The weight of the engines and body of the flier sits lower than the rotors to create a pendulum effect that discourages the contraption from tipping upside down and creating what might be called the lawn dart effect.
“People come up and go, ‘Is it safe?’ ” Mr. Martin said. “Safety is a relative thing. We think we have done a lot to make this by far the safest jetpack ever built.” But, he acknowledged, “It’s not a high bar.”
He added, “I’ve got to get my head around the fact that at some point, somebody is going to have a very bad experience.”
So far, he said, he and his team of developers have not taken the device higher than six feet. “We set that very deliberately,” he said, to ensure that they fully understand controlling the invention before taking it to more dangerous altitudes. “If you can fly it at 3 feet, you can fly it at 3,000,” he said.
Only 12 people have flown the jetpack, and no one has gained more than three hours of experience in the air. Mr. Martin plans to take it up to 500 feet within six months. This time, he said with a smile, he will be the first.
Mr. Martin said he had no idea how his invention might ultimately be used, but he is not a man of small hopes. He repeated the story of Benjamin Franklin, on first seeing a hot-air balloon, being asked, “What good is it?” He answered, “What good is a newborn baby?”
At the demonstration on Tuesday, a large crowd formed and watched as Harrison took the device a few feet off the ground, barely visible over the heads of the spectators.
"That's a little anticlimactic," said Bob Oliver, a retired airline pilot from Alamo, Calif. But Joseph Tevaarwerk, who helped develop the craft's engine, noted that the world's first airplane flight was only about 12 seconds long. And he added "would you have wanted to be there when the Wright brothers launched?"
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