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Tethered, Water-Powered Jetpack Provides Two Hours of Flight Time
arshadk writes "Unlike 'ordinary' jetpacks, the JetLev is actually two vehicles, tethered by a hose the thickness of your thigh. On the water is a small speedboat-like unit which contains a 250 horsepower motor and a pump. This is connected to the pack — into which you strap your frail body — by a 10-meter hose. The water is pumped from the sea or lake below up to the nozzles on the jetpack, providing a 1,900-Newton thrust, enough to lift a human weighing up to 150 kilos."
You're then pulling along a 20km hose behind your rocket, and that hose has to be strong enough to support its own weight. You're going to add more weight than you're subtracting.
Unless you built a 20km tall tower that the hose hangs down from and as the rocket ascends you retract the hose so the rocket doesn't have to carry the slack. But then you have to build a 20km tall tower that can hold an enormous amount of hose (still sturdy enough to be 20km long) and the weight of the fuel item you're moving, and since that weight is going to be on one side of the tower you'd have to counterbalance it on the other side. Tricky.
Why is 2 hours of flight time an apparent selling point for this thing? Why would anyone need or want to hover a few feet above the surface of a lake for 2 hours nonstop? Granted, you can "fly" much longer than in more traditional jetpacks, but it seems a bit like bragging about a car that can go 600 miles on a single tank but is permanently tethered to the gas station.
That said, it sure looks fun to try.
Jet Pack Runs For Hours On Water
Posted by kdawson on Tuesday February 17 2009, @06:11AM
from the got-your-back dept.
Ponca City, We love you writes
Jet packs have been around for half a century, but there's always been one problem: they run out of fuel in around 30 seconds. Now a German company has taken the standard jet pack design, run a fat yellow hose out the back, and connected it to a small unmanned boat that houses an engine, pump, and fuel tank and sends pressurized water up the hose, where it's shot out by two nozzles just behind the wearer's shoulders. Called the JetLev-Flyer, the design purportedly can reach a height of 15 meters, a speed of 72 kph, and a range of 300 kilometers based on four hours of flying time. A digital fly-by-wire system is used to control the throttle. Future designs may achieve higher altitudes, higher top speeds, and extended range, and even travel below the water's surface. The American manufacturers claim it is 'amazingly easy to learn and operate' and they're taking orders now at $130,000 each.
It's 2009 again!
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Not a dupe, the old article was about him trying to bring this thing to market. He's now selling these to anyone with the cash.
put the what in the where?