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Rocket Men
Posted by
Zonk
on Sun Oct 08, 2006 07:51 PM
from the excellent-reason-to-go-into-traction dept.
from the excellent-reason-to-go-into-traction dept.
theodp writes "Slate reports on the guys who really, really want to fly, who got together the other week at the Niagara Aerospace Museum for the First International Rocketbelt Convention. To date, only 11 men in history have free-flown a rocketbelt (aka JetPack). More men have walked on the moon. Why? 'It's not a matter of if you get hurt, it's when,' says Eric Scott, an ex-stuntman who's in the exclusive club."
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The 1970's Jet Pack... (Score:3, Interesting)
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Gyroscopic stabilizers (Score:5, Interesting)
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Re:Gyroscopic stabilizers (Score:5, Informative)
Also, don't forget you have to build the rocket motors and feed system and such. Most belts so far are peroxide monopropellants -- a good choice IMHO, but peroxide is hard to get and takes a lot of care to handle safely. And building any size rocket motor and ensuring it's safe enough to stand next to is a bit of work.
What I'm saying is, if you're a single amateur, or a small group, then building just the rockets is a big project unto itself. It shouldn't surprise you that no one has the time, money, and skills to do that, *plus* build and test the IMU, *plus* write fly-by-wire control software for it. If a modest sized startup company decided to pursue the matter, with a bit of financial backing, I would expect they could get it all built without too much hassle (provided they had the appropriate expertise in all areas, obviously). Oh, and don't forget that your software has to handle a non-fixed CG if the person moves about much at all.
Parent
Re:Gyroscopic stabilizers (Score:5, Interesting)
Why not? There are gyros that model helicopters use that are cheaper than $100, and an RC chopper is a whole lot twitchier than something with the mass of a human being in it. If your flight only lasts for a couple of minutes, then you hardly need high-precision gyros that won't drift more than a degree per hour.
-jcr
Parent
Re:Gyroscopic stabilizers (Score:4, Insightful)
I suppose you could use the inexpensive ones, as long as your goal was to change the pilot requirement from "top of the line test pilot" to "very good helicopter pilot," and not an attempt to make it flyable by anyone with a bit of simulator practice.
You might do an ok job if the gyros just tried to hold the spin *rate* to zero, and let the pilot handle leveling the vehicle; one fewer integral makes for much slower error growth.
Parent
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This doesn't make any sense. If you've got attitude sensors and the means to alter the attitude through computer control of thrust, it's a programming problem.
College classes routinely build autonomous helicopters, so you can obviously reduce the "piloting" to
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But I wanted to point out that the parent brought up a good point about accuracy. The simple fact is you can't get around the inherent error in such sensors over time. For example, if we have one gyro just m
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I do know that at least until recently, inexpensive gyros were completely unusable. Modern ones appear better, but my sources suggest that they aren't all the way ther
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I'm not sure they've actually conducted a fullly autonomous test. According to their web site [armadilloaerospace.com], they've only done very limited tethered tests.
However, I know the Delta Clipper [nasa.gov] (DC-X) and it's follow on (DC-XA) had several sucuessful tests, fully autonomous. But even they had a bunch of development issues that eventually lead to the programs cancellati
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Duff Man! (Score:2, Interesting)
hes sponsored by the Go Fast Sports and Beverage Co.
I wonder if he can do the pelvic thrust and Heuuugh?
The link I pointed to contains a movie of him in action (and other stuff).
rocket "belt" (Score:3, Insightful)
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It seems to me you have to concentrate so much on remaining upright that you would working too hard to have fun and actually enjoy a flight.
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Re:rocket "belt" (Score:4, Funny)
--
#11. No pirate shall ever wear a "fanny pack".
Well, I think your
Parent
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The rocket belt made its first appearance in comic strips like Flash Gordon around 1934. It is everyone's evokes dream of someday flying like a bird, without the need for magic.
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How many people have flown a jetpack? (Score:5, Funny)
Make that 12, your forgetting Duke Nukem.
Sounds like a job for real-time computers (Score:4, Interesting)
But even in the late 1960s my aero-and-astro student colleagues told me that even the Boeing 727 was too unstable to be controlled by a human pilot using reflexes alone: it relied on "yaw dampers," servo mechanisms that amounted to electronic analog computers, to tame the raw behavior of the plane.
The Boeing 777 is a completely "fly-by-wire" design.
It seems to me that it ought to be possible to design microprocessor-controlled rocket belts that would be much easier and safer to fly than those of the 1960s. (Including, of course, electronic active noise cancellation in the helmet to provide at least some reduction of the "deafening noise 3 feet three feet from his ear."
Trying to fly the rocket belts described in the strikes me as rather like trying to fly a full-size, exact model of Langley's Aerodrome. It may be possible--for someone with the reflexes of a Santos-Dumont and the nerves of an Evel Knievel--but it's still just a stunt. The Wright Brothers achievement was ''not'' building an aeroplane that could get off the ground; it was building an aeroplane that they ''and others'' could get (relatively!) ''safely'' off the ground.
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OK, now the next problem is to find a fuel light enough that you can stand up and walk around with more than 20 seconds' worth hanging on your back.
rj
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Got it: It's called "gasoline".
How you get a significant amount of its stored energy released in a useful way by a rocket motor is left as an exercise for the reader.
-jcr
The second problem (Score:2)
Ok, what's the third problem?
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Refueling it, probably. Those hybrid solid-fuel/liquid-oxidizer engines are fine for a single burn, but a tad time-consuming to reload.
-jcr
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What? Their first airplanes were insanely unstable. It was harder to control than a F/A-22 now, except the F/A-22 has a powerful computer to keep it stable. It had next to no dihedral and its horizontal stabilizer was in front of the plane, while the vertical stab had next to no moment (so it was pretty use
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I am not sure if active noise cancellation systems bode well with aperiodic noise sources. There is time lag involved in DSP and sound will not stand and wait. It travels 3 feet through air in ~3ms, and through rocketbelt frame even faster. Perhaps a passive solution, like i.e. aerogel helmets as well as shields or bells around nozzles reflecting
What about women? (Score:4, Informative)
According to the Wikipedia article [wikipedia.org], at least one woman (Isabel Lozano [tecaeromex.com]) has flown one as well (happened almost a month ago).
As to why haven't more people flown the device, take a look at Isabel's pictures, and you'll see that had to make a custom cast of her body for the mounting hardware the device uses. Also, for some reason many people may not feel very comfortable with jets of gas at 740 C venting at supersonic velocities mere inches from their body.
Dan East
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On the Fringe (Score:5, Interesting)
And then there's the whole RB2000 saga, which involved fraud, murder, and the disappearance of the only prototype. The full story can be found on the rocketbelt.nl site. Rocketbelt developers are out there on the edges with the ufologists, perpetual motion researchers, and free energy salesman, with the exception that rocketbelts can actually work!
A rocketman will be at this year's X-Prize Cup (Score:2)
The Alternative? (Score:4, Interesting)
2006: The year of the very light jet [ainonline.com]
Very Light Jet Magazine [verylightjets.com]
The Light Jet Age [cnn.com]
OK, so they are a $1-2 million. That's a lot of money. From what I've read, however, these jet packs aren't that cheap either. (They're not mass produced so the price hasn't dropped at all.) If you bought part of a jet as a time share, with say 20-50 other people, the price drops significantly. It is a viable option for some people.
If you want to fly... (Score:2)
Undocumented (Score:3, Funny)
I take it this excludes burrito dinner + sparks accidents?
Not safe? What a surprise! (Score:2)
They also have a really short range. Something like several hundred feet, maybe 1000. Still, they're very cool to watch, and that in itself is the only reason it ever needed to be invented. They got some use on several TV shows back in the 70s and I see
Segway (Score:2)
The secret of rocket packs is to.... (Score:2)
Well it worked for me every time in "Rocket Ranger" on my Amiga all those years ago....
Re:And this is different from (Score:4, Insightful)
Parent
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Re:And this is different from (Score:4, Funny)
What? You mean those Mountain Dew commercials aren't accurate representations of the sport of skateboarding?
Parent
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Well, in that case, it's different because skateboards don't have pressurized tanks of propellant that's dangerous to get on your skin, don't have multiple pieces of complex machinery, all of which is required to operate as designed in a fairly harsh environment in order to ensure your continued survival, and furthermore are fundamentally st
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Wait, remind me why that's a bad thing?
Or did you mean '<'? ;)
-:sigma.SB
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In fact, forget the rocket belt and the blackjack.
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In Korea, only old people wear rocket belts!
And that's why old people die!
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Sorry to do this, but.... (Score:2)
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In the case of the A4 rocket i think they used potassium permanganate, as this is even more reactive than silver when it comes to catalysing the peroxide to water and oxygen.
Actually now when i think of it the same system was also used in the Redstone rockets of the 50's and 60 (which was basically just