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The Truth About New Jet Pack Hype

An anonymous reader writes "This week a sub-$100,000 rocket belt was unveiled and will be on sale this summer, but that's the sad thing: it's still not a real jet pack. Here's a fascinating inside look at the human-flight industry, full of law-suit scandals, technical difficulties, fuel-economy woes and endless delays. The good news? It all points to the next generation of rocketeer research, with real applications for medical rescue and military technology actually coming on the horizon. From the article: 'With a little patience, and a little funding, we could actually have the pleasure of grumbling over regulatory issues we never dreamed possible. Like being limited to specific kinds of air strips, because the jet strapped to your back is classified by the FAA as an ultralight. Or being required to wear a ballistic parachute, because Amarena's Thunderjet design could reach altitudes as high as 10,000 feet (and, for the record, speeds of up to 160 mph, provided someone can solve wind-resistance issues).'"

205 comments

  1. OMG! by Recovering+Hater · · Score: 0, Offtopic

    It hasn't been tagged with whatcouldpossiblygowrong yet!?

    --
    My humor is probably your flamebait
    1. Re:OMG! by somersault · · Score: 1

      Because we know what could possibly go wrong - it rhymes with flat, and often results in fairly flat objects too.

      --
      which is totally what she said
  2. Jetpacks are just a bad idea by elrous0 · · Score: 4, Insightful
    The problem with the "Jet pack" is that it is an inherently foolish and inefficient idea. That much power, in that small a space, with that many stability issues makes for a nasty combo. Lifting ANY aircaft straight up off the ground and landing if softly in the same way is VERY tricky, even for a well-trained human operator (ever wonder why helicopter autopilots are so rare?). Trying do do that with a small mechanism that can fit on or be carried around by a single human is even more tricky. With tolerances that tight, the slighest windgust or miscalculation could send your jetpack spirally helplessesly out of control as you plummet to the ground.

    Just because it looks cool in a Bond movie doesn't mean that it will ever be practical in real life.

    --
    SJW: Someone who has run out of real oppression, and has to fake it.
    1. Re:Jetpacks are just a bad idea by Harmonious+Botch · · Score: 3, Interesting

      And there is the noise. I've been within 100 yards of one in operation, and conversation with the person next to me was impossible. They really are not fit for urban areas.

    2. Re:Jetpacks are just a bad idea by morgan_greywolf · · Score: 2, Insightful

      Stuff that's really, really cool is only occasionally very practical.

    3. Re:Jetpacks are just a bad idea by yog · · Score: 3, Interesting

      These are technical problems that can be fixed. Put in a gyro and a directional laser and a computer to control it all and you're good to go. Maybe radar and collision avoidance software as well. You shouldn't have to worry about navigating around other objects in the air; your jet pack will have all the smarts it needs under the hood to take care of such things.

      As for noise, put a muffler on the jet. Of course, a Harley jet pack would probably not come with one.

      I would love one of these. I am so sick of being forced to commute along this predetermined, crowded and narrow little route along with hundreds of thousands of others every day. All that tension, stress, and road rage, not to mention the speed traps. It is so dangerous and inefficient. It would be simpler, faster, and safer to just hop the 25 miles to my destination. And so much more fun.

      Just imagine a city full of these devices. People wouldn't need ground garages anymore. Streets could be dug up and replanted to reverse global warming and beautify the city (but leave enough for bike lanes). No more stoplights, no more running over pedestrians.

      Bring'em on!

      --
      it's = "it is"; its = possessive. E.g., it's flapping its wings.
    4. Re:Jetpacks are just a bad idea by starfishsystems · · Score: 3, Insightful

      Yep. Anything short of nicely modulated antigravity is a non-starter for me. Let's see, why is that? Because even the kinetic energy of my own body falling from my own height can be enough to cause permanent injury? Or because superheated gases sufficient for lift are being generated immediately next to me?

      --
      Parity: What to do when the weekend comes.
    5. Re:Jetpacks are just a bad idea by d+cobalt · · Score: 1

      yeah so you get a really small person

    6. Re:Jetpacks are just a bad idea by veganboyjosh · · Score: 5, Insightful

      I wonder how different the parent post is from what people had to say when they first heard internal combustion engines...

    7. Re:Jetpacks are just a bad idea by Anne_Nonymous · · Score: 1

      >> Just because it looks cool in a Bond movie doesn't mean that it will ever be practical in real life.

      I suppose this means a rocket launcher mounted on my 'burb beater is out of the question too.

    8. Re:Jetpacks are just a bad idea by 192939495969798999 · · Score: 4, Insightful

      Yeah, ever play that game "Lunar Lander"? Now imagine that if you land wrong, you actually die on the first try. I don't know anyone that landed that thing on the first try, and all it has is dumb little 2-d zigzag mountains. Imagine high-voltage lines, trees,etc. and this thing is a one-way trip to the rube goldberg/darwin award winner's list... the most scientifically advanced way to do something extremely risky.

      --
      stuff |
    9. Re:Jetpacks are just a bad idea by Ced_Ex · · Score: 1

      I'd figure urban areas would be perfect for something like this. Just don't use the jetpack for sustained flight, but more as a "jump pack" to get you up and across rooftops, escaping alleyways and such.

      --
      Live forever, or die trying.
    10. Re:Jetpacks are just a bad idea by jdigriz · · Score: 3, Insightful

      >Just imagine a city full of these devices. People wouldn't need ground garages anymore. Streets could be dug up and replanted to reverse global warming and beautify the city (but >leave enough for bike lanes). No more stoplights, no more running over pedestrians.

      Don't be ridiculous, how are people going to bring home groceries with a jet pack? Or a new flatscreen tv? Or a sheet of plywood? Where would you fit the baby seat for taking the little ones to the grandparents? Commuting to work in a thunderstorm would either suck or be really really dangerous with a jetpack. And don't get me started on starling season or bird migrations in general. We'll always need ground streets unless you've got a skytruck/skycar to go with your jetpack. Yes, being able to fly around would be very cool, and I'd probably buy one if they could be made relatively failure resistant and reasonably priced but they can't replace the automobile in all cases any more than motorcycles/bicycles can. So we still need roads.

    11. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      I choose to live in my fantasy world. Why are you killing my dreams??!?!!?!!!!111

    12. Re:Jetpacks are just a bad idea by fishbowl · · Score: 1

      >I am so sick of being forced to commute along this predetermined, crowded and narrow little route along with
      >hundreds of thousands of others every day.

      You could move so that you work someplace reasonably near where you live. I put a dollar value (tens of thousands a year) on that, plus the commute time.

      --
      -fb Everything not expressly forbidden is now mandatory.
    13. Re:Jetpacks are just a bad idea by somersault · · Score: 1

      That's completely accurate. Which is why I have my rockets strapped to my feet, whose stability issues I solved around the age of 1 years old

      -- Iron Man

      --
      which is totally what she said
    14. Re:Jetpacks are just a bad idea by Dancindan84 · · Score: 2, Funny

      Put in a gyro and a directional laser and a computer to control it all and you're good to go. This program has performed an illegal operation and will be shut down.
      If the problem persists, contact the program vendor.

      "*&^%!! REBOOOooo...___"
      --
      "Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
    15. Re:Jetpacks are just a bad idea by somersault · · Score: 5, Funny

      All that tension, stress, and road rage, not to mention the speed traps. It is so dangerous and inefficient. Absolutely correct. All you should really need for jetpack commutes in busy airspace is a jousting pole, a good helmet, and perhaps some air to air missiles
      --
      which is totally what she said
    16. Re:Jetpacks are just a bad idea by somersault · · Score: 1

      So we all train up in GTA: San Andreas first, what's the big deal? :P Plus that stupid lander couldn't even land 10 degrees off the normal or it would crash, but humans tend to be able to move their legs around to compensate for that kind of thing. Or are you talking about coming in too fast rather than landing at an angle? Because that would suck :O

      --
      which is totally what she said
    17. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      These are technical problems that can be fixed. Put in a gyro and a directional laser and a computer to control it all and you're good to go. Maybe radar and collision avoidance software as well. You shouldn't have to worry about navigating around other objects in the air; your jet pack will have all the smarts it needs under the hood to take care of such things.
      And that's why YOU are a filthy rich inventor with a house in Malibu. Oh, wait... Where did you say your mother's basement was?
    18. Re:Jetpacks are just a bad idea by Applekid · · Score: 2, Interesting

      I'd rather have some kind of liquid turned cabling on release... like a "spider's web" that I could "fling" to attach to objects and use that to propel myself through the city.

      People would call me The Human Spider.

      --
      More Twoson than Cupertino
    19. Re:Jetpacks are just a bad idea by myspace-cn · · Score: 1

      The engineering problem is as such. How to make you break gravity and fly like a fireball through the sky without.. (and I repeat without) lighting your ass on fire!

    20. Re:Jetpacks are just a bad idea by nastro · · Score: 1

      Sure, jetpacks may be a bad idea. _You_ try taking Chuck Norris' away.

    21. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 5, Funny

      I wonder how different the parent post is from what people had to say when they first heard internal combustion engines...
      As seen on the bulletin board in a small English town:

      > First!!1!

      > I, for one, welcome our new internally combusted overlords.

      > The problem with the "internal combustion engine" is that it is an inherently foolish and inefficient idea. That much power, in that small a space, with a highly inflammable fuel makes for a nasty combo. Creating that many small controlled explosions can be very tricky, even for a well-trained human operator.

      > And there is the noise. I've been within 100 yards of one in operation, and conversation with the person next to me was impossible. They really are not fit for urban areas.

    22. Re:Jetpacks are just a bad idea by Hojima · · Score: 1

      I completely agree with your statement. Not only is it impractical (not to mention inefficient), but it is taking away funds from much more important aeronautical research. If more money was pumped into the development of synthetic strong materials that are capable of supporting large vacuum pockets, efficient solar panels, and then making them cheap, there could be an ultra light-weight flying device that hardly requires any lift (or could require none in the rare scenario that the material is buoyant), and in turn energy. If this device was fairly large scale, and in mass production, international flights would become cheap enough to be regarded as subway travel. Not to mention that it's countless times better to live next to work than it is to jet pack to it.

    23. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      I'd mod you +5 Practical if I could

    24. Re:Jetpacks are just a bad idea by tist · · Score: 1

      Well, OK, an autopilot for a helicopter doesn't make much sense because it doesn't spend a lot of time going in one direction very long. Not really designed for that. I have noticed though that things like the Saturn five rocket and the shuttle get straight off the ground and don't have someone at the controls...
      By the way, a "jet pack" and a "rocket pack" are two completely different animals. A rocket works by pouring a fuel and an oxidizer into a small space (usually burning) and blasting them out through a nozzle. The only moving parts are in the pumps. There are solid versions too that just don't have pumps but still burn some fuel and squeeze it out of a nozzle. A jet pack, needs a whole lot of rotating parts (compressor and turbine at least) and also barfs out a lot of hot stuff.

    25. Re:Jetpacks are just a bad idea by compro01 · · Score: 1

      i would wonder if some kind of strength-supplementing exoskeleton would be more efficient/effective for that task.

      --
      upon the advice of my lawyer, i have no sig at this time
    26. Re:Jetpacks are just a bad idea by dzfoo · · Score: 4, Funny

      I'm pretty sure there's prior art on that. People call him Spider-Guy, or something.

            -dZ.

      --
      Carol vs. Ghost
      ...Can you save Christmas?
    27. Re:Jetpacks are just a bad idea by dwiget001 · · Score: 1

      I am waiting for the anti/modulated gravity packs. Internal combustion and liquid fuel engines are so 20th century for me.

    28. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      Chuck Norris doesn't need a jetpack to fly. He just uses one because it makes him look even more awesome.

    29. Re:Jetpacks are just a bad idea by zippthorne · · Score: 1

      I don't think they'd make a good transportation tool, but quick jumps to rooftops would be great for roofers, antenna installers, chimney inspectors, billboard painters... anyone who needs quick access to a high spot that doesn't have easy stair access.

      But it would have to be more convenient than a ladder. If it takes ten minutes to strap the thing on, it wouldn't be all that useful.

      --
      Can you be Even More Awesome?!
    30. Re:Jetpacks are just a bad idea by dzfoo · · Score: 1

      "Ah, I see that you have started the My Jet Pack action. Do you want me to engage the My Auto Pilot option?"

            -dZ.

      --
      Carol vs. Ghost
      ...Can you save Christmas?
    31. Re:Jetpacks are just a bad idea by Isauq · · Score: 1

      Why does Spiderman never get tagged for littering?

      --
      RTFM
    32. Re:Jetpacks are just a bad idea by flink · · Score: 1

      His webbing is designed to break down within 90 minutes or so.

      Duh! :P

    33. Re:Jetpacks are just a bad idea by Harmonious+Botch · · Score: 2, Informative

      Internal combustion engines can be muffled with only minor losses of power output, for the noise comes out of one place ( the exhaust manifold ) and the power comes out in a second place ( the drive shaft ). But a jet pack, the power and the noise both come from the same place, and it is difficult to cut noise without substantially cutting power.

      Furthermore, the most successful noise-limiting devices on any jet - I'm thinking passby fans on turbines - adds a great deal of weight. On a jetliner this can work, but on a jetpack adding lots of weight will render it useless. ( Remember, the power-to-weight ratio for a modern jetliner is less than 10% of the power-to-weight ratio of a jetpack. )

    34. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      So you're more of a ninja rope kind of guy, then?
      Really, though, who cleans up that stuff? Window washers everywhere would call you That Web-slinging Bastard.

    35. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      "Just because it looks cool in a Bond movie doesn't mean that it will ever be practical in real life."

      You mean all that pussy on company time?

    36. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 1, Funny

      People were right about the internal combustion engines.

    37. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      i am imagining a city full of these ... with people crashing left right and centre ... i find it hard to imagine that people who often have a difficult time navigating a car in basically two-dimensions having to now keep in mind a vertical dimension to their travel ... *shudders*

    38. Re:Jetpacks are just a bad idea by Jeff+DeMaagd · · Score: 2, Insightful

      A lot of people aren't liking the noise of jet aircraft, which is still pretty loud despite advancements in noise reduction. I can't imagine a whole lot of people liking to wake up to the rumble of a 130+ dB jet pack being fired in their neighbor's driveway.

    39. Re:Jetpacks are just a bad idea by nickruiz · · Score: 1

      Too bad. I would've wanted to see his flying roundhouse kick while strapped to a jet pack finisher on Walker Texas Ranger.

    40. Re:Jetpacks are just a bad idea by zippthorne · · Score: 1

      Large vacuum pockets??

      You do realize that you only get ~13% more lift out of a hypothetical massless bag filled with "vacuum" compared to that bag filled with helium, and only 6% compared to hydrogen.

      Further, the economics don't work. International travel by airship is slow* (compared to current methods) and extremely slow compared to a subway jaunt across town. There simply won't be enough people interested in it, even if airships are the only option, to drive the price down to daily-commute levels.

      *Unless you're talking about an "international" trip from Brussels to Amsterdam.

      The money pumped into jetpacks is small, and the problems for jetpacks are the same problems other aircraft of similar capabilities or size have, so it's not exactly irrelevant. With regard to "efficient solar panels" (and they're already pretty efficient, the goal ATM is "cheap." It doesn't matter how great the quantum efficiency is if it takes more energy to produce one that you get back during its lifetime) You can't get results quicker just by pumping money into it any more than you can you can get a baby in a month by employing 9 surrogate mothers.

      --
      Can you be Even More Awesome?!
    41. Re:Jetpacks are just a bad idea by plurgid · · Score: 1

      Dude, have you EVER stood next to a jet engine?
      I used to work at an airport, I have.
      Hearing protection only helps to an extent.

      Them shits is loud, son. A whole 'nother level of loud, yo.
      word.

    42. Re:Jetpacks are just a bad idea by Spokehedz · · Score: 1

      Aside from the fact that his webs breakdown within an hour, but you would be surprised how many people don't get hit for littering.

      I was outside Nathans a couple weeks ago, and this guy from "Fuggin Brooklyn, and 'm fugging hungry!" (his words, not mine) was eating 4 with everything on it, and one of NYC's finest was standing next to a garbage can, just watching the people. The guy from Brooklyn stood up, and literally tossed his boxes and paper on the ground, and walked right past the cop. The cop saw the whole thing, but did nothing.

    43. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      Are you fo' real?

      Dawg?

    44. Re:Jetpacks are just a bad idea by mcmonkey · · Score: 1

      Put in a gyro and a directional laser and...

      So do you carry the shark, or does he get his own jet pack?

      But seriously, many of the issues with jet packs have been exposed in 3 AM stoner conversations on super powers.

      Ok, you can fly. Without the full compliment of additional super powers, the power of flight on its own just doesn't live up to the hype.

      Will you be immune cold at high altitude? Will you be able to breathe in thin air? Will your arms be able to carry anything heavier than what you could carry on the ground? Will your sense of direction, ability to judge distances, etc. be any better than they are now?

      Just imagine a city full of these devices.

      I see the same traffic jams, just a few thousand feet higher than before. Maybe having a jet pack is like being able to read minds. Lots of fun if you're the only one, maybe not so much if every one else can do it too.

    45. Re:Jetpacks are just a bad idea by trolltalk.com · · Score: 2, Insightful

      >>"Plus that stupid lander couldn't even land 10 degrees off the normal or it would crash, but humans tend to be able to move their legs around to compensate for that kind of thing. "

      Nobody ever broke a leg when parachute jumping - they all did it when hitting the ground | tree | whatever.

    46. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      Malibu

    47. Re:Jetpacks are just a bad idea by petermgreen · · Score: 1

      The problem with those is that if you actually used them or even exposed them and got noticed by law enforcement then specalist law enforcement and/or the military would be on your tail almost immediately. Probablly with orders to shoot to kill.

      --
      note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
    48. Re:Jetpacks are just a bad idea by Codifex+Maximus · · Score: 1

      > A lot of people aren't liking the noise of jet aircraft

      They like the thought of walking from LA to NYC even less...

      Some cool ideas and their problems:
      Jet/Rocket Pack - Flight duration, landing gear gets easily damaged, excessive cost, safety.
      Autogyro - Reduced need for airfield, regulation, moderate cost, training. /nice/
      Airplane - Need for airfield, regulation, training, high cost.
      Helicopter - Regulation, training, high cost.
      Ground Effect Vehicle - Need for specially constructed thruways. /This is a great idea!/
      Hang glider - Subject to excessive wind conditions and landing gear is easily damaged.

      --
      Codifex Maximus ~ In search of... a shorter sig.
    49. Re:Jetpacks are just a bad idea by mapmaker · · Score: 1
      The problem with the "Jet pack" is that it is an inherently foolish and inefficient idea. That much power, in that small a space, with that many stability issues makes for a nasty combo.

      You could say the same thing about motorcycles, but I wouldn't give mine up for anything in the world.

    50. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      I WANT TO BELIEVE

    51. Re:Jetpacks are just a bad idea by cayenne8 · · Score: 1
      "And there is the noise. I've been within 100 yards of one in operation, and conversation with the person next to me was impossible. They really are not fit for urban areas."

      It couldn't be any worse than the SUV's I've heard lately with the 'boyz' playing Hip Hop so loud...well, at least with the bass so loud, that it shakes things in every house for a block.

      If a jet pack could cover that up...it might be a welcome change!

      :-)

      I have to wonder...don't those people like anything in the treble or midrange?

      --
      Light travels faster than sound. This is why some people appear bright until you hear them speak.........
    52. Re:Jetpacks are just a bad idea by cayenne8 · · Score: 2, Insightful
      "You could move so that you work someplace reasonably near where you live. I put a dollar value (tens of thousands a year) on that, plus the commute time."

      Some of us prefer to live in nicer/safer neighborhoods. And people that have kids...often want to live where their kids are in the better school districts (if not in private school). That and some others...like having some 'elbow room' where they live, and don't wanna be cramped up next to someone else....a nice yard or even a good plot of land is nice to many. Most of us don't like living in urban apts...

      --
      Light travels faster than sound. This is why some people appear bright until you hear them speak.........
    53. Re:Jetpacks are just a bad idea by akunkel · · Score: 0

      I am pretty sure if you take a Mentos before using it you will be fine.

    54. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      Bury the power lines. Put soft, padded landing zones in the place of streets and sidewalks.

      As far as falling your own height causing permanent injury (parent), you also gotta look at the flip side of that coin. People have fallen from upwards of 22,000 (yes, three zeros) feet without a parachute and walked away from it. Plus, if we replace Driver's Ed with courses in landing and such, it wouldn't be so bad. As VR technology grows, we could eventually likely simulate the feel of a rough landing, and have jetpack flight simulators. Plus, if you've taken any good martial arts classes, or simply know a thing or two about the human body, you know that there's a right way to fall (to avoid injury) and a wrong way, and the difference between them.

    55. Re:Jetpacks are just a bad idea by element-o.p. · · Score: 1

      I agree that a jet pack is inherently inefficient, but I'm not so sure it's inherently foolish. A classical jet pack requires one thing: brute force, much like a Saturn-V. It's not flying, it's simply a matter of exerting enough thrust to shove you into the air, and yes, that's inherently inefficient. As for whether or not that's foolish...well, that depends upon how it is being used. One hundred years ago, people thought it was foolish to try to fly -- we're humans, not birds, and if God had meant for us to fly, etc., etc. But look at how crippled our society would be without air travel now. If a jet pack is built that can be used by rescue crews, then I suspect 10 out of 10 people rescued would think the jet pack was the greatest thing EVER .

      I imagine that you are probably correct about the stability issues in a jet pack, but the Wright Flyer was inherently unstable, too. IIRC (I don't have a link handy, sorry, but I think this was in AOPA magazine within the last year), there was a group that tried to build and fly a duplicate of the Wright Flyer for the 100th anniversary of powered flight, and their pilots -- all experienced pilots -- found the thing to be incredibly difficult to control. I imagine that with further refinement, stability and controllability problems in jet packs can be ironed out just as they were overcome in fixed wing airplanes and later, in helicopters.

      --
      MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
    56. Re:Jetpacks are just a bad idea by Scamwise · · Score: 1

      Internal combustion engines have proved to be pretty fatal and to have quite number of other nasty side effects as well.

      --
      Sam "to lazy to register" Look
    57. Re:Jetpacks are just a bad idea by odinjurkowski · · Score: 0

      Sure this could all be solved. At some point we wouldn't have to worry about noise, navigation, landing, flight time, etc. But the big problem is why I don't ride a bike to work: weather. It may be fun on a nice day, but rain, sleet, freezing ice and snow, would force me back into a car. I don't want to show up to work dripping wet or frozen like a Popsicle.

    58. Re:Jetpacks are just a bad idea by Applekid · · Score: 1

      and get noticed by law enforcement then specalist law enforcement and/or the military would be on your tail almost immediately. You can use the number of stars on your HUD as an indicator of the strength of law enforcement against you. Once you've got the national guard on you, getting ahold of one of their tanks should be your top priority if you want to keep your crime spree going.

      If you chicken out, you can always use the spray shop. Or just load your last saved game.
      --
      More Twoson than Cupertino
    59. Re:Jetpacks are just a bad idea by element-o.p. · · Score: 1

      Ummm...most airplanes aren't fit for urban areas. My airplane http://www.gecko-ak.org/N600LW only has a 50hp Rotax engine, but I'd bet my neighbors would lynch me if I were to fire it up in my back yard.

      --
      MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
    60. Re:Jetpacks are just a bad idea by element-o.p. · · Score: 1

      Just don't buy the Micro(cket-)soft version of the jetpack and you'll be fine :D (laugh, it's a joke!)

      --
      MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
    61. Re:Jetpacks are just a bad idea by xhrit · · Score: 1

      can i get stroybombs on mine?

    62. Re:Jetpacks are just a bad idea by Diakoneo · · Score: 1

      Excellent alternative!

      1. Pour Coke into tank
      2. Drop in several Mentos tablets
      3. Take off using cheap, alternative fuel
      4. ???
      5. Profit!

      --
      "Well..here I am..." - Jubal Early
    63. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0, Funny

      I don't think they'd make a good transportation tool, but quick jumps to rooftops would be great for roofers, antenna installers, chimney inspectors, billboard painters... anyone who needs quick access to a high spot that doesn't have easy stair access.
      There is only one such application I can think of - firefighting. Firefighters' "reactive belts" should be powered by pressurized water, from the firehose umbilical. Water beats any propellant gas, because of its density and resulting reactive push. Once the flying firefighters reach the windows or the roof and can step on a solid support, they could cut the water out from their flight belt nozzles and redirect it to hand-aimed extinguisher nozzle with a flip of a valve (bad thing to do while in flight, of course), to carry on with their mission. Furthermore, another nozzle could be used to cut the doors or dry walls down, instead using the hatchet.
    64. Re:Jetpacks are just a bad idea by Hektor_Troy · · Score: 1

      I always thought it was "The Master of Web" or "Web Master" or something like that.

      --
      We do not live in the 21st century. We live in the 20 second century.
    65. Re:Jetpacks are just a bad idea by elrous0 · · Score: 1

      Put soft, padded landing zones in the place of streets and sidewalks.

      Reminds me of the comedian who joked "Why don't they just build the entire aircraft out of the stuff they use to make the black boxes?"

      --
      SJW: Someone who has run out of real oppression, and has to fake it.
    66. Re:Jetpacks are just a bad idea by elrous0 · · Score: 1

      Chuck Norris doesn't need a jetpack. Gravity knows better than to fuck with him.

      --
      SJW: Someone who has run out of real oppression, and has to fake it.
    67. Re:Jetpacks are just a bad idea by permaculture · · Score: 1

      This 'Personal helicopter' looks cool, though mouth-dryingly dangerous:

      http://www.c00lstuff.com/1150/Personal_helicopter/

      --
      Environmentalism is the new Victorianism. Everyone ties on a green corset and pretends we're virtuous.
    68. Re:Jetpacks are just a bad idea by AndersOSU · · Score: 3, Informative

      Decreasing jet noise is in fact very difficult, but it is also a major area of research in mechanical engineering departments across the country.

      No, unfortunately this massive research thrust isn't aimed at making jet packs more practical, but rest assured, gains in reducing aircraft jet noise could be applied to jet packs.

      The noise a jet makes is the result of turbulent mixing of the high speed jet with the low speed surrounding air. Some solutions are simple, like the chevron edges on the Boeing 787 others are a bit more complicated involving heating, cooling, or electrically charging the exiting jet. The goal being always to make the mixing of the jet and surrounding air less turbulent. Suffice to say you're not likely to have a picnic next to an operating jet engine anytime soon, but it is an active area of research.

    69. Re:Jetpacks are just a bad idea by BostonPilot · · Score: 1
      As a helicopter pilot who flies a helicopter with an autopilot... it's not as difficult as you make it out to be, especially with the miniaturization of computer systems.

      There are two bigger problems that I see: The smaller the area producing downwash, the less efficient the craft is. Think Harrier versus a typical helicopter. A typical helicopter has a rotor system 25-40 feet in diameter, while a Harrier engine outlet is only a few feet across. There's a reason why the fuel line for the Pegasus engine is as big as your arm. The noise is also related, again think Harrier versus a helicopter. A helicopter isn't necessarily quiet, but compared to a Harrier they're silent!

      The other problem is engine failure. Although BRS to some degree addresses that problem, that adds weight which is going to adversely affect range, power, etc. Also, even BRS systems have parts of the envelope they can't protect you in - a friend watched a guy die in an ultralight - the structure failed too close to the ground. The BRS deployed, but did not inflate in time to reduce the vertical impact.

      If you look at a lot of work that got done right after WWII on personal sized helicopters, they tried to address a lot of these issues. Notice that we still don't see a lot of man portable helicopter systems!

    70. Re:Jetpacks are just a bad idea by EarwigTC · · Score: 1

      Tagged: whatethcouldpossiblygowrongeth

      --
      Promote civility: mod down any post starting with 'ummm'.
    71. Re:Jetpacks are just a bad idea by PirateBlis · · Score: 0

      hahaha Win. You sir are awarded 15 internets

    72. Re:Jetpacks are just a bad idea by Rhys · · Score: 1

      I would love one of these. I am so sick of being forced to commute along this predetermined, crowded and narrow little route along with hundreds of thousands of others every day. All that tension, stress, and road rage, not to mention the speed traps. It is so dangerous and inefficient.


      There's this thing around some places called PUBLIC TRANSPORTATION(*). Maybe you should give up the car and try it?

      (*): Not available in all areas. May be overcrouded, running late, or on strike.
      --
      Slashdot Patriotism: We Support our Dupes!
    73. Re:Jetpacks are just a bad idea by springbox · · Score: 1

      That's why the Jet Car will be invented shortly after

    74. Re:Jetpacks are just a bad idea by goatpunch · · Score: 1

      No discussion about the foolishness of personal flying devices is complete without mentioning the Aerocycle "Since the operator stands on a tiny platform with a pair of naked helicopter blades whirling beneath him at food-processor speeds there is a great inducement not to fall off." (btw the whole site is worth a look)

    75. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0
      Just because it looks cool in a Bond movie doesn't mean that it will ever be practical in real life.

      Oh, but with it's 75 second flight time, the Thunderjet is perfect for window washers for tall buildings. And the economy version, which omits the parachute, at the same time solves the illegal immigrant population problem.

    76. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      It's alright, slashdot isn't coding. You are allowed to put a / to separate things or even a comma instead of an OR |

    77. Re:Jetpacks are just a bad idea by iminplaya · · Score: 1

      Dude, have you EVER stood next to a jet engine?

      Not while it's running...

      --
      What?
    78. Re:Jetpacks are just a bad idea by B4D+BE4T · · Score: 1

      All that tension, stress, and road rage, not to mention the speed traps. It is so dangerous and inefficient. That tension and stress will be much higher when these new flying commuters start falling through ceilings all around your neighborhood. Imagine going to work every day wondering, "Will there be a roof on my house when I get home?" Or imagine what would happen if every single person you saw on the road today had a pilot's license and could fly around just as dangerously as they were driving their cars.
    79. Re:Jetpacks are just a bad idea by plurgid · · Score: 1

      LOL ... NEXT to, not IN FRONT of. :-)

      In all seriousness, there is a piece of equipment called the Aft Power Unit (APU) which is essentially a jet engine in a box on wheels, that you cart out to the plane and hook up to pump air through the turbines when it's parked at the gate. On the older model planes, it runs ac and heat and stuff.

      Bar none, that is the LOUDEST f-ing thing I've ever dealt with ever. It was so loud the vibrations from from just standing around it used to make the muscles in my chest cavity ache.

      I was always scared shitless that something was gonna come loose in it and it was gonna blow apart, but it never did.

    80. Re:Jetpacks are just a bad idea by iminplaya · · Score: 1

      Bar none, that is the LOUDEST f-ing thing I've ever dealt with ever.

      Then you never heard a Wankel with open headers.

      --
      What?
    81. Re:Jetpacks are just a bad idea by DeathElk · · Score: 1

      Chuck Norris is a jetpack. A waiting jetpack.

    82. Re:Jetpacks are just a bad idea by i_b_don · · Score: 1

      hang glider ..."and landing gear is easily damaged"

      I love this especially considering that hang gliders pilots LAND ON THEIR FEET!!!

      lol

      don

      --
      all language nazi's will burne in heil!
    83. Re:Jetpacks are just a bad idea by i_b_don · · Score: 1

      You guys are killing me here.

      Approach this like an engineer. Straight hovering thrust is too much power. It's wasteful on energy, dangerous from the amount of power required, and we can't actually do it. bummer. Ok, so what we need is something with wings, that would be good. And the whole jet idea sucks from the noise perspective. ok... so lets use an internal combustion engine so we can muffle the noise. Hm... but it's got to be light and cheap. how about under $10k? sound fair? And we need to have a backup parachute in case there are problems.

      Sound good? Oh wait! This already exists!!

      http://www.mosquitoamerica.com/

      YES Under 10k
      YES Internal combustion engine
      YES No louder than a loud lawnmower
      YES has wings
      YES has backup parachute

      Speed, ~40 MPH
      MPG, near infinite ... if you're good at thermaling

      Granted there are some draw backs. A few big ones are that it requires some skill to fly (kind of like a car to drive), storage space passenger space suck, wind will ground you, and the biggest hurdle is of course, you need take off and landing space.

      But really, are those hurdles harder than getting a jet pack working????

      don

      --
      all language nazi's will burne in heil!
    84. Re:Jetpacks are just a bad idea by sjames · · Score: 1

      If the millitary can fly deliberatly unstable aircraft, then the stability issues with a jetpack can certainly be managed. Really the greatest difficulty is that jet exhaust is much too hot to allow contact with the human operator.

      At the same time, I don't expect to see commuter jetpacks all that soon. I wouldn't be surprised to see them first as specialized rescue equipment (since both costs and risks are more acceptable in rescue operations). At one time, the millitary was a prime cantidate but with progress on UAVs, the jetpack has less of a potential role there now. Once established as standard equipment for rescue, they'll slowly make their way to extreme sports and then general recreational use.

    85. Re:Jetpacks are just a bad idea by sjames · · Score: 1

      Automated cars are a much more likely solution. Traffic would flow much faster if not for the idiots constantly changing lanes to get 5 whole feet ahead or who think merging traffic wants to drag race. Urban parking isn't such a problem if your car can drop you off at the front door then go find a parking spot somewhere. Even greater efficiency could be had if automated cars were provided as public transport. Then rather than go park, the car could go pick up someone else.

    86. Re:Jetpacks are just a bad idea by Anonymous Coward · · Score: 0

      Ahem. "Those people?"

    87. Re:Jetpacks are just a bad idea by Jeff+DeMaagd · · Score: 1

      People generally accept jet aircraft. I don't know why you mention cross continental walking. That's beside my point. I'm just pointing out that there's a significant political and societal hurdle for "jet packs", even if the technological ones are fixed. As yet, I don't think any "jet pack" has operated for more than 30 seconds at a time.

    88. Re:Jetpacks are just a bad idea by elrous0 · · Score: 1

      Yeah but with a motorcycle crash at least you can still brake a motorcycle a little as you slide, and skid along the ground when you hit--dispersing much of the energy along the way and maybe surviving. Lose control of a jetpack and it's pretty much a straight fall to the ground.

      --
      SJW: Someone who has run out of real oppression, and has to fake it.
  3. orly by gazbo · · Score: 1
    and, for the record, speeds of up to 160 mph, provided someone can solve wind-resistance issues

    I suspect if you could "solve the wind resistance issues" most airborne transportation could get one hell of a lot faster than that.

    1. Re:orly by Stanistani · · Score: 2, Funny

      You just need to find someone who is aerodynamically curvaceous.

    2. Re:orly by techpawn · · Score: 1

      Wind resistance? Oh come on! This is rocket science! It isn't exactly rocket science here...

      Wait...

      --
      Ask not what you can do for your country. Ask what your country did to you
    3. Re:orly by Anonymous Coward · · Score: 0

      Yea except without wind resistance there would be no flight at all...

  4. old school jet-pack movies by fifedrum · · Score: 4, Insightful

    Two fun facts about this project that were glossed over in the old school movies of these things in action are the NOISE and the short flight times.

    The TV series Wings covered the first generation of these jet packs and broke my heart when they revealed the true story behind the promotional movies. The pilot wasn't flying for the whole movie, of course, the film crew filmed a few seconds of flight, the pilot would land, refuel and the whole process was repeated and pasted together in post-production. They also dubbed new sounds over the outrageous screech/howl the original packs made.

    Watching the film as a kid, I clearly remember thinking there's no way the thing could fly for that long, but the excitement of seeing a guy fly through the woods overcame my skepticism. Clearly though, even with the new films and fuels, we have the same jet pack, the same limited range, the same ear shattering exhaust note. Nothing new IMO.

  5. Imagine a pair of these in the trunk by Babu+'God'+Hoover · · Score: 3, Funny

    of your flying car. You could go anywhere!

    1. Re:Imagine a pair of these in the trunk by superpulpsicle · · Score: 1

      1. Segway (done)
      2. Jet pack (done)
      3. Back to the future hoverboard (next)
      4. Wonder women invisible plane (next)

    2. Re:Imagine a pair of these in the trunk by Pojut · · Score: 1

      The Back to the Future hoverboard is by far the most fun sounding one on that list:-) I loved that thing!

    3. Re:Imagine a pair of these in the trunk by jandrese · · Score: 1

      The invisible plane was always an odd accessory IMHO. It's stealthier than a regular plane, but you still have the fully visible squatting woman zipping through the air. Plus, it's gotta be harder to fly when you can't see the controls (or readouts!). And lord help you if you forget where you parked it. Plus, it's a public nuisance to park it anywhere there might be people. The last thing WW needs is some jogger getting a concussion from running smack into her invisible jet head first.

      --

      I read the internet for the articles.
    4. Re:Imagine a pair of these in the trunk by Jason+Levine · · Score: 1

      Not to mention the embarrassment if you need to use the invisible bathroom. (Cue Family Guy quote.)

      --
      My sci-fi novel, Ghost Thief, is now available from Amazon.com.
    5. Re:Imagine a pair of these in the trunk by BattleApple · · Score: 1

      At the least, you'd have a pretty cool Knight Rider-esque turbo boost!
      http://www.youtube.com/watch?v=arL04K3HLMw

  6. same problems as hovercraft by rcpitt · · Score: 2, Interesting

    When we had a service here in Vancouver the initial problem was that if it was classified as a boat it was not allowed to go faster than 15 knots in the harbour -

    and if classified as an airplane it was not allowed to fly under the Lions Gate bridge.

    Some technologies simply don't fit in our pre-conceived systems.

    Think of the problems we'll have when we finally crack the problem of personal anti-gravity for our vehicles ;)

    --
    Been there, done that, paid for the T-shirt
    and didn't get it
  7. Meh by billius · · Score: 1

    As soon as they make one that's cheap and looks cool enough so that it makes Jennifer Connelly fall in love with me I'll be on board. Until then, I wanna try one of those sweet wing suits out over some Norwegian fjords!

  8. soccor moms by BigJClark · · Score: 3, Funny


    I just had a mental image of soccor moms firing themselves into walls at biblical porportions, drinking a latte, chatting on the cel phone,

    I hope there is an IQ minimum *shudder*

    --

    Hi, I Boris. Hear fix bear, yes?
    1. Re:soccor moms by 4D6963 · · Score: 4, Funny

      I hope there is an IQ minimum

      Nah, IQ tests are too long to pass. Would be much quicker to ask people to spell out "soccer" instead.

      --
      You just got troll'd!
    2. Re:soccor moms by BigJClark · · Score: 1

      hahahaha, ah man... busted! Touche, touche :)

      --

      Hi, I Boris. Hear fix bear, yes?
    3. Re:soccor moms by Anonymous Coward · · Score: 0

      I don't. All our laws that protect the stupid from themselves have resulted in downbreeding of the general population. We would be doing our species a favor if we let the stupid ones kill themselves off. It is true that they will unfortunately take some of the non-stupid ones with them, but the long term benefits outweigh the short term drawbacks IMO.

    4. Re:soccor moms by meringuoid · · Score: 1
      Would be much quicker to ask people to spell out "soccer" instead.

      OK. F... o... o...

      --
      Real Daleks don't climb stairs - they level the building.
    5. Re:soccor moms by Anonymous Coward · · Score: 0

      "soccer": f-o-o-t-b-a-l-l

    6. Re:soccor moms by triffid_98 · · Score: 1
      Good plan, lets implement that right after we let the religious zealots fight each other for world domination. Jews, Muslims, Catholics, Hindi, Buddhists, all in a no hold barred cage match LIVE ON PAY PER VIEW this Saturday at the Baghdad Arena. As soon as we declare a winner can hand them all complimentary jet packs.

      We would be doing our species a favor if we let the stupid ones kill themselves off. It is true that they will unfortunately take some of the non-stupid ones with them, but the long term benefits outweigh the short term drawbacks IMO.
    7. Re:soccor moms by AlgorithMan · · Score: 1

      or "cell phone" or "proportions" ;-)

      --
      The MAFIAA is a bunch of mindless jerks who will be the first up against the wall when the revolution comes
    8. Re:soccor moms by The_reformant · · Score: 1

      So americans aren't allowed to use one either, because the rest of the world knows that the correct spelling of "soccer" begins with an f.

      --
      I have discovered a truly remarkable sig which this post is too small to contain.
  9. Damn the parachute? by fahrbot-bot · · Score: 4, Insightful
    Or being required to wear a ballistic parachute, because Amarena's Thunderjet design could reach altitudes as high as 10,000 feet.

    Or any "reasonable" height for that matter. Jet pack use does not fail gracefully. No glide ratios or gyroscopic descents, just Ahhhhhh... splat. A parachute sounds like a fairly good idea here.

    --
    It must have been something you assimilated. . . .
    1. Re:Damn the parachute? by rwyoder · · Score: 4, Insightful

      Or being required to wear a ballistic parachute, because Amarena's Thunderjet design could reach altitudes as high as 10,000 feet. Or any "reasonable" height for that matter. Jet pack use does not fail gracefully. No glide ratios or gyroscopic descents, just Ahhhhhh... splat. A parachute sounds like a fairly good idea here.
      To restate what he is saying:
      • What is the powerplant failure mode of a fixed-wing a/c? It becomes a glider.
      • What is the powerplant failure mode of a rotary-wing a/c? It becomes an auto-gyro.
      • What is the powerplant failure mode of a jet pack? It becomes a large rock.
      The flying car concept (based on ducted fans) has the same fatal flaw.
    2. Re:Damn the parachute? by randyest · · Score: 1

      Parachutes aren't all that useful at low altitudes (even low altitudes more than high enough to kill you in a fall.) I think I'd hang out up around 5-10k feet as much as possible so I'd have time to open the chute on a fall.

      --
      everything in moderation
    3. Re:Damn the parachute? by Detritus · · Score: 1

      The Russians have some very good ejection seats that manage to get the pilot out, deploy a parachute, and land safely, in low altitude situations where you might think that it was hopeless.

      --
      Mea navis aericumbens anguillis abundat
    4. Re:Damn the parachute? by fahrbot-bot · · Score: 1
      Parachutes aren't all that useful at low altitudes ...

      True for the most part, but I believe a "ballistic parachute" has a mechanism to delopy and open quickly so it's more useful at much lower altitudes.

      --
      It must have been something you assimilated. . . .
    5. Re:Damn the parachute? by YrWrstNtmr · · Score: 1

      The newer ejection seats, Russian/US/European, are all zero/zero. Zero airspeed, zero altitude. Or at weird angles.

    6. Re:Damn the parachute? by D3 · · Score: 1

      Even with a parachute, there are times just after take off or just before landing that a chute won't do any good. Lift failures during either of those results in a rock wrapped in nylon falling to the earth.

      --
      Do really dense people warp space more than others?
    7. Re:Damn the parachute? by fahrbot-bot · · Score: 1
      ...there are times just after take off or just before landing that a chute won't do any good.

      I believe a "ballistic parachute" has a mechanism to delopy and open quickly so it's more useful at much lower altitudes. I don't know if it would help in takeoff/landing modes though.

      --
      It must have been something you assimilated. . . .
  10. You Said It by Jane+Q.+Public · · Score: 1

    You can only store so much energy in a package that is liftable by a human being. That has always been, and has remained, their biggest practical failing. A jet or rocket pack that only gives you even 10 or 20 minutes of flight time (much less the more-typical 20 seconds), is just not very practical.

    1. Re:You Said It by fishbowl · · Score: 1


      >You can only store so much energy in a package that is liftable by a human being.

      Show me in your physics book where it says there is an upper bound on the amount of energy you can put into a system.

      --
      -fb Everything not expressly forbidden is now mandatory.
    2. Re:You Said It by smussman · · Score: 2, Insightful


      >You can only store so much energy in a package that is liftable by a human being.

      Show me in your physics book where it says there is an upper bound on the amount of energy you can put into a system.

      E = mc^2
    3. Re:You Said It by Teancum · · Score: 1

      If you can make a human-portable nuclear reactor of any kind (including conventional reactors... or even a quality RTG that has sufficient shielding to be within inches of human reproductive organs), I would love to see it right now!

      I just don't see how storage of any quantities of energy in a form denser than high explosive chemicals is going to be safe... and even that stretches the definition of something safe.

    4. Re:You Said It by fishbowl · · Score: 1

      >>>You can only store so much energy in a package that is liftable by a human being.

      >>Show me in your physics book where it says there is an upper bound on the amount of energy you can put into a
      >>system.

      >E = mc^2

      And the maximum mass liftable by a human being is? (Are we limiting this to the average adult, on Earth?)

      --
      -fb Everything not expressly forbidden is now mandatory.
  11. Insensitive clod by sam_paris · · Score: 1, Funny

    You insensitive clod, you just killed my dreams of being the rocketeer

    :'(

  12. Flight time measure. by Mushdot · · Score: 1

    As long as I can build my rocket ship with it I don't care if the flight time is only 35 seconds!

  13. Wait, solving what? by jesdynf · · Score: 1, Insightful

    "Solving" wind resistance? Golly gee, that sounds like a great idea. Maybe after that's in the bag, we'll "solve" the energy it takes to boost an object into orbit, or we'll "solve" the atmosphere lowering the power yield of terrestrial solar panels.

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  14. I'm already dead... by Anonymous Coward · · Score: 0

    ...from holding my breath.

  15. Bah! Wind Resistance Issues by Phoenix666 · · Score: 4, Funny

    I solve wind resistance issues by coating myself with astroglide.

    --
    Do what you can, with what you have, where you are.
    1. Re:Bah! Wind Resistance Issues by Overzeetop · · Score: 4, Funny

      Who let Richard Gere's gerbil post to slashdot?

      --
      Is it just my observation, or are there way too many stupid people in the world?
    2. Re:Bah! Wind Resistance Issues by Anonymous Coward · · Score: 0

      You know they were only kidding when they told you what to do with that rolling donut, right?

    3. Re:Bah! Wind Resistance Issues by The+One+and+Only · · Score: 1

      I tried that once. It was an overrated experience.

      --
      In Repressive Burma, it's not just your connection that dies. slashdot.org/comments.pl?sid=314547&cid=20819199
    4. Re:Bah! Wind Resistance Issues by Deadstick · · Score: 1

      Then you'll be up against blowing resistance.

      rj

    5. Re:Bah! Wind Resistance Issues by jollyreaper · · Score: 1

      I solve wind resistance issues by coating myself with astroglide. The next day, the Jolly Green Giant is at the proctologist's office, blushing furiously. "There I was,tending my fields and I bent over to take a closer look at something and--"

      "At least that's more inventive than saying you slipped and fell in the shower," the doctor sighed.
      --
      Kwisatz Haderach
      Sell the spice to CHOAM
      This Mahdi took Shaddam's Throne
  16. "...regulatory issues ..." by Tim+Ward · · Score: 1

    Including, please, banning such toys from any and all airspace that anyone with a proper pilot's licence might want to fly in. I've had one near miss with a toy already and that's enough thanks.

    (OK, it was just a child's balloon, and I didn't hit it. But I really don't want to come across untrained idiots who can take my aircraft out of the sky if I hit them.)

    1. Re:"...regulatory issues ..." by jshackney · · Score: 1

      (OK, it was just a child's balloon, and I didn't hit it. But I really don't want to come across untrained idiots who can take my aircraft out of the sky if I hit them.)

      I've seen those balloons as high as 20,000 feet. I thought they would have expanded and popped long before that altitude.

      Fly along the east coast (NY, Teterboro, DC, etc.). I hate it out there, ATC always brings you down to around 6,000 feet 50 to 100 miles from your destination and now you're mixing it up with all the GA gnats who can't seem to figure out how to properly calibrate (or even turn on) their transponders. I've had so many friggin' close calls out there I refuse to fly single-pilot in that airspace now.

      BTW, I have nothing against GA. Just the people that think they own the sky and have no regard for how incredibly crowded it has become in the past 20 years.

  17. Ballistic Parachute? by Anonymous Coward · · Score: 0

    Why would you need a ballistic parachute at 10,000 feet? Wouldn't a normal parachute work just as well at that height?

    But, I can see how it would help at 30 feet...

  18. Why is it "not a real jet pack?" by randyest · · Score: 3, Interesting

    It looks like a jet pack. It's a pack, on the guy's back, and it flies -- apparently with some kind of jet-like propulsion system. Neither article appears to answer this question that the summary gives as axiomatic. Anyone know?

    --
    everything in moderation
    1. Re:Why is it "not a real jet pack?" by Frosty+Piss · · Score: 3, Informative

      A jet engine is a reaction engine that discharges a fast moving jet of fluid to generate thrust in accordance with Newton's third law of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets and pump-jets, but in common usage, the term generally refers to a gas turbine Brayton cycle engine, an engine with a rotary compressor powered by a turbine, with the leftover power providing thrust. Jet engines are so familiar to the modern world that gas turbines are sometimes mistakenly referred to as a particular application of a jet engine, rather than the other way around. Most jet engines are internal combustion engines but non combusting forms exist also.
      -- Wikipedia

      Sounds like a jet pack to me.

      --
      If you want news from today, you have to come back tomorrow.
    2. Re:Why is it "not a real jet pack?" by WastedMeat · · Score: 1

      I didn't see an air intake; if it contains its own oxidizer it is rocket.

    3. Re:Why is it "not a real jet pack?" by randyest · · Score: 2, Informative

      Wait, sorry -- I found it:

      all models on the verge of availability are, in fact, jet-free and called, officially, rocket belts.

      OK, I guess that's technically right. But is that really a "sad thing" that makes any real difference, or just splitting hairs? I'll take any kind of personally-mounted flying device without bitching about the technical means of propulsion.

      --
      everything in moderation
    4. Re:Why is it "not a real jet pack?" by blincoln · · Score: 1

      But is that really a "sad thing" that makes any real difference, or just splitting hairs?

      My understanding is that a true jet pack would be much more fuel-efficient. I believe it's accurate to say that a rocket pack/belt has to carry all of its reaction mass (in the form of whatever is blown out the nozzles), whereas a jet pack just has to spin the turbine and gets the reaction mass for thrust from the atmosphere. IANAAE, though.

      --
      "...always new atoms but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman
    5. Re:Why is it "not a real jet pack?" by Carnildo · · Score: 2, Informative

      OK, I guess that's technically right. But is that really a "sad thing" that makes any real difference, or just splitting hairs? I'll take any kind of personally-mounted flying device without bitching about the technical means of propulsion.


      A rocket belt needs to carry its own oxidizer and reaction mass. A jetpack gets the oxidizer and reaction mass from the atmosphere. The difference in fuel economy is incredible.

      Another difference is that a jetpack is regulated as an aircraft (specifically, an ultralight). A rocket belt is unregulated.
      --
      "They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
    6. Re:Why is it "not a real jet pack?" by element-o.p. · · Score: 2, Informative

      Short answer -- a jet uses outside air as the oxidizer. A rocket carries an oxidizer with it. These devices carry H2O2 in a tank to use as an oxidizer. Therefore, this is a rocket pack, not a jet pack.

      I suspect they are using rockets rather than jets because a jet requires a series of turbines to compress the air for combustion, but the (liquid) fuel and oxidizer are pumped into the rocket engine, making the rocket engines simpler and lighter.

      --
      MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
    7. Re:Why is it "not a real jet pack?" by ScreamingCactus · · Score: 1

      I don't think there's actually any combustion going on or heat generated. In fact it's probably cold because it looks like compressed co2 or something similar. And by the way, I knew Rob Schneider's career was going downhill, but cameraman in a rocket belt video???

      --
      The path to enlightenment is truly through homemade drugs!
  19. All I know by DRAGONWEEZEL · · Score: 1

    is that I could really use a Jet pack to get the aerobird swift out of a tree. It's about 75ft up, and I tried the wrist rocket / 65lb uglywire(p.s., it's more like 25lb) method to yank it out w/o any success.

    Anyone know where I can just "borrow" a rocket belt in the south puget sound area?

    --
    How much is your data worth? Back it up now.
    1. Re:All I know by Anonymous Coward · · Score: 0

      But what will they use to get you out of the tree? I suspect the local FD or Coast Guard helicopter rescue team will not be amused. But it'd probably be worth a good laugh on the evening news.

  20. It is possible to get it right... by mcrbids · · Score: 1

    In case you haven't seen it before, you outta take a look at the real jet-man. No, I'm not kidding. Know your limitations and work with them!

    BTW: this guy is FREAKIN NUTZS but I sure wish I had cajones like his - this would be such a RIP!!!!

    --
    I have no problem with your religion until you decide it's reason to deprive others of the truth.
    1. Re:It is possible to get it right... by Codifex+Maximus · · Score: 1

      mcrbids said:
      > In case you haven't seen it before, you outta take a look at the real jet-man. No, I'm not kidding. Know your limitations and work with them!

      Wow. I saw this youtube video and all I can say is Freakin Awesome! I want one.

      --
      Codifex Maximus ~ In search of... a shorter sig.
  21. Ducted Fans Instead? by MrSteveSD · · Score: 1

    On model aircraft people often use ducted fans instead of real jets. I wonder if that would be a better solution for personal flight systems like this?

    1. Re:Ducted Fans Instead? by Overzeetop · · Score: 1

      Mythbusters tried a ghetto version of this with poor results. That's an awful lot of momentum flying about near your head. Then again, it's not like traditional rocket packs score high marks in the "don't strap explosives to your body" school of self preservation.

      --
      Is it just my observation, or are there way too many stupid people in the world?
    2. Re:Ducted Fans Instead? by Harmonious+Botch · · Score: 1

      Ducted fans tend to be more efficient as speed increases ( levels off around 300-400 mph, I think ). At hovering speeds they are horribly inefficient.

    3. Re:Ducted Fans Instead? by engineerofsorts · · Score: 1

      The kids on MythBusters already tried this--using "plans" advertised for sale in the back of some magazine such as Popular Mechanics. Net was that the power-to-weight ratio of internal combustion engines w/ ducted fans just wouldn't cut it for this application.

      --
      Life is tough. Life is even tougher when you're stupid.
  22. 33% more bs by Anonymous Coward · · Score: 0

    The number of companies looking to sell them to private consumers has increased by as much as 33 percent in the last week alone. Meaning there are now four. Does anyone else find this a little misleading?
  23. Glider? by phorm · · Score: 1

    How about one that's somewhat of a jet-assisted glider design?

    1. Re:Glider? by blincoln · · Score: 1

      I am thinking a good compromise might be a VTOL system with lightweight wings which are folded until it reaches the minimum flight level. Sort of like Hawk in the old Captain Power TV series, or a higher-powered version of the wingsuit guy with the scale jet turbines attached to his boots. Part of the reason I think a jetpack would be cool is that ability to take off and land without a runway (otherwise why not just use an ultralight?), but it does seem wasteful of fuel to not use wings in level flight.

      --
      "...always new atoms but always doing the same dance, remembering what the dance was yesterday." -Richard Feynman
    2. Re:Glider? by element-o.p. · · Score: 1

      Even wings just big enough to hold a 200lb person are pretty big. Assuming a coefficient of lift of 1.6 (fairly reasonable for a typical wing design), a density of 0.007...ummm...slugs, IIRC, and a landing speed of 25mph (still pretty fast for your feet, but we'll go with it for now), your wing area is...:

      lift = 1/2*0.007*velocity^2*coefficient of lift*area

      therefore, 200 lbs = 1/2 * 0.007*(25mi/h * 5280ft/mi * 1h/3600s)^2 * 1.6 * area

      and therefore, wing area is 200 / 7.53 which is 26.6 square feet.

      Assuming an aspect ratio (wing span / wing chord) of 6 (typical for light aircraft), that means your wing is 12.6 feet from wingtip to wingtip and just over 2 feet from the leading edge to the trailing edge. Okay, that's big, but not impossible. Unfortunately, that's just for the glider. If you now strap a 180lb rocket pack on, your wing gets even bigger -- now your wing is 17.4 feet from wingtip to wingtip and just under 3 feet from l.e. to t.e. That's getting pretty awkward :(

      --
      MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
    3. Re:Glider? by i_b_don · · Score: 1

      You've just described this, but with an internal combustion engine instead of a jet.

      http://www.mosquitoamerica.com/

      --
      all language nazi's will burne in heil!
    4. Re:Glider? by element-o.p. · · Score: 1

      Sweet!!! Although the landing skids in the back make me think you'd better keep your face elevated when landing

      --
      MCSE? No, sir...I don't do Windows. Yes, I am an idealist. What's your point?
  24. I will patent myself ... by jetpack · · Score: 1

    ... For I am the perfect jetpack. I work for hours on minimal fuel, and the fuel I consume is biodegradable.

    1. Re:I will patent myself ... by Anonymous Coward · · Score: 0

      ... For I am the perfect jetpack. I work for hours on minimal fuel, and the fuel I consume is biodegradable.
      We won't talk about the exhaust fumes though, will we.
  25. Yves Rossy's Idea is a bit more fun by Anonymous Coward · · Score: 0
  26. Comment removed by account_deleted · · Score: 5, Informative

    Comment removed based on user account deletion

  27. You rock. Slashdot sucks. by Anonymous Coward · · Score: 0

    I'm setting your self promoting blog to be my new home page.

  28. The problem with personal jetpacks and flying cars by Digi-John · · Score: 1

    Is that most people seem unable to do very well in two dimensions; drive the freeway much? Everyone thinks a flying car would be GREAT because they envision themselves as the only people having one. Now imagine the sky over San Francisco completely packed with these things. You take off in the morning, and instead of just looking two ways before getting onto a street, you have to check above you and on all sides before lifting into the air, only to be smashed into by some hippie who just came through that patch of fog. Oh, and then you fall 50 feet to the ground and explode. "The solution is to have predetermined lanes of travel for flying cars!", you say? I know, we can call them "sky-roads", and there will be on-patterns and off-patterns and little narrow residential sky-roads, and of course for safety you will all fly at the same altitude.

    --
    Klingon programs don't timeshare, they battle for supremacy.
  29. Jetpacks and Math don't mix? by Phat_Tony · · Score: 3, Interesting

    from the article:

    "The number of companies looking to sell them to private consumers has increased by as much as 33 percent in the last week alone... while last year there were two commercial rocket-belt manufacturers... there are now three."

    Going from two to three would be a 50% increase, not "as much as 33 percent"

    --
    Can anyone tell me how to set my sig on Slashdot?
  30. JetCat by Thelasko · · Score: 1

    There's a company called JetCat that makes miniature jet turbine engines for model airplane use. In the past few years some daring individuals have strapped a few of these engines to their bodies and have flown. You may have seen the video's on YouTube(sorry, no links to YouTube while I'm at work). I'm disappointed there was no mention of this in TFA.

    --
    One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
    1. Re:JetCat by Anonymous Coward · · Score: 0

      The specs of the JetCat P200 (their largest model) illustrate perfectly the primary difficulty of all vertical flight: carrying enough fuel to get any significant range. According to the web site, the P200 weighs 5 lbs, produces 45 lbs (!) of thrust, and consumes 2 lbs of fuel PER MINUTE, or 120 lbs per hour. An actual jetpack would probably need about 10 times that amount of thrust, therefore consuming 20 lbs of fuel PER MINUTE, or 600 lbs (about 100 gallons) per hour. Of course, to lift 600 lbs of fuel, you need even MORE thrust, and therefore higher fuel consumption, etc., etc.

    2. Re:JetCat by Thelasko · · Score: 1

      You make a valid argument. However, who says we need vertical flight? Maybe just for takeoff, but the daredevils who are attempting this either wear nylon wing-suits or strap carbon fiber wings to their backs. You should really watch the videos. It's quite impressive.

      --
      One of our competitors trademarked the term "hypothesis". From now on, we will call them "boneheaded ideas".
  31. Duh, his webs are bio-degradable by marcus · · Score: 1

    I guess you never read the comic book.

    --
    Good judgement comes from experience, and experience comes from bad judgement.
    - W. Wriston, former Citibank CEO
  32. Unforseen consequences... by Anonymous Coward · · Score: 0

    So, I wonder how much explosive a svelte terrorist could carry...

    - T

    1. Re:Unforseen consequences... by loafula · · Score: 1

      leave it to a coward to post this... to answer your question, though, a bit less than could be carried on bicycle, it'd probably be somewhat less than could be carried on foot, much less than could be carried in a car, and significantly less than could be carried in an airplane.

      --
      FOXTROT UNIFORM CHARLIE KILO
    2. Re:Unforseen consequences... by Carnildo · · Score: 1

      So, I wonder how much explosive a svelte terrorist could carry...


      A rocket pack weighs in at about 180 pounds, including 100 pounds of highly explosive fuel/oxidizer mix. If the terrorist could carry the rocket pack, they could just as easily carry 180 pounds of explosive on foot.
      --
      "They redundantly repeated themselves over and over again incessantly without end ad infinitum" -- ibid.
  33. Wrong tactic by sxltrex · · Score: 1
    You should have had Roland Piquepaille put a link to it on his blog, then submit it to /. for you. Works every time!


    I kid, I kid!

  34. Low Rent Video by splitsevin · · Score: 1

    Obviously they're passing the savings from their borrowed VHS camcorder craptastic demo video to their customers. Wait, do they have customers? I just want one so I'm bitter.

    --
    The enemy of my enemy is quite possibly also my enemy. I've made a lot of enemies.
  35. Chainsaw. by HornWumpus · · Score: 1

    Much simpler and achieves the same goal. That goal being a wrecked model and down or burned to a crisp tree.

    Try a long fishing pole with a heavy weight. Someone with a good cast will be able to snag the model for you. Use a big treble hook if all else fails. Be prepared to lose a lot of weights, hooks and line.

    (sociopath) Offer the nearest 'climber monkey' kid a $10-$20 reward for climbing up and getting it down. If he falls 'think of it as evolution in action' (/sociopath ).

    --
    John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
    1. Re:Chainsaw. by DRAGONWEEZEL · · Score: 1

      LoL...

      Yeah, I allready lost alot of weights. And I used some "65lb" line too! I have been slowly breaking branches around it for a few weeks now!

      But a jetpack would be quicker, and might be able to retrieve the plane in 3 pieces!

      Next, I may build a ladder into the tree "tree-fort" style.

      --
      How much is your data worth? Back it up now.
  36. Ah come on by Plazmid · · Score: 1

    Come on what's the danger in strapping a container of 98% hydrogen peroxide to your back? Sure 98% hydrogen peroxide is unstable, but its not that unstable. The only problem is getting 98% hydrogen peroxide these days, people are worried that terrorists could use it to make explosives or something.

  37. Why this will never "fly" by FreakerSFX · · Score: 1

    Auto accidents kill millions annually. Most accidents are preventable incidents caused by human error - a very small portion are actually caused by vehicle failure.

    The technology is being developed to allow vehicles to drive themselves. At some point this will be a feasible means of controlling vehicles safely.

    The mainstream would never accept it. We want to be in control - we're more efficient than machines. We don't want to hand our freedom over to a system.

    Many drivers struggle for lane discipline in 2 dimensions. They brake in corners and follow dangerous lines which would result in disaster if they had to make any changes due an unexpected lane blockage or vehicle movement. Add in a 3rd dimension. Add in the same resistance to a computer-controlled vehicle. Add in a more volatile fuel.

    This would result in a disaster. Jet packs and flying cars are a dream and will remain so as long as we resist the incursion into our freedom.

    Still a flying car with fly-by-wire controls and auto-levelling software would address some of it - I really can't see that in a jet pack though.

    --
    This sig contains a manual self-destruct. Kindly please put your foot through your monitor in 8 seconds.
  38. It's all fun and games until by unassimilatible · · Score: 2, Funny

    you get behind some asshole on his cellphone.

    --
    Slashdot "libertarians": Small government for me, big government for those I disagree with. -1, I disagree with you
  39. Re:More (better) info on jetpacks by Daniel+Dvorkin · · Score: 1

    Thanks for that very informative essay.

    --
    The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  40. No more running over pedestrians. by Anonymous Coward · · Score: 0

    We don't run over pedestrians any more. We just fall on them when we run out of fuel.

  41. Medical rescue by DoofusOfDeath · · Score: 1

    with real applications for medical rescue

    Definitely. Now we're going to need ways to get 45-year-old men wearing a spent rocket pack down from the top of a redwood tree.

  42. Why military by Anonymous Coward · · Score: 0

    Why do Slashdot articles always discuss military uses for any possible new technology? Are the editors all a bunch of war-fetishists or something?

    1. Re:Why military by GigG · · Score: 1

      Because the military is where the money is to move technologies like this along.

      --
      Is buying a Harley Davidson as your first motorcycle since you were 16 at age 49 a midlife crisis issue?
  43. Well, yeah... by Jane+Q.+Public · · Score: 1

    Okay. There IS a limit, as shown by the other reply. But I concede your point. What I meant to say was: "There is a limit to the chemical energy you can fit into a package that is liftable by a human being."

    1. Re:Well, yeah... by Discordantus · · Score: 1

      Disclaimer: IANAP (P=physicist)
      I think the answer is still very close to the same. I'm sure that scientists haven't discovered all the chemical bonds that are possible. It is conceivable that there are undiscovered molecular bonds that hold gigantic amounts of energy. Since that energy has mass, the theoretical upper bound really is defined by e=mc^2.

    2. Re:Well, yeah... by Jane+Q.+Public · · Score: 1

      Sure there are. They are already well-known. Compounds with extremely high-energy chemical bonds are called... explosives.

      Seriously. The practical issue here is not just fitting the energy into the package, but also controlling it safely. I had assumed that was a given.

  44. Re:More (better) info on jetpacks by Chris+Johnson · · Score: 1

    Definitely the best article yet- sorry you didn't get the attention you wanted, but at least your article is better :)

  45. And while you're at it... by Anonymous Coward · · Score: 0

    These are technical problems that can be fixed. Put in a gyro and a directional laser and a computer to control it all and you're good to go. Maybe radar and collision avoidance software as well. You shouldn't have to worry about navigating around other objects in the air; your jet pack will have all the smarts it needs under the hood to take care of such things.

    And while you're at it, you might as well add some control surfaces to augment directional control and stability, and how about a ballistic recovery parachute system in case of failure of your engine or thrust vectoring system, which also brings up the idea of maybe also some wings so you can glide to a better forced landing area in case you'd otherwise have to deploy the BRS over a really hostile place like a power transformer distribution station or a sewage treatment plant. And after you've got all that stuff added, you might as well be able to take a friend along for a ride too, so why not add another seat or two , and for passenger comfort how about an enclosed cabin too Next thing you know, you've ended up with one of these babies which would be very cool to own indeed.

  46. Mothers Against Drunk Flying by nickruiz · · Score: 1

    All those technical ramifications for no jet packs are certainly valid, but what about those poor organizations against operating machinery while under the influence?

    MADF just doesn't make any sense, unless you have a speech impediment.

  47. I am Iron Man by Trogre · · Score: 1

    Something like that suit the guy in the upcoming Iron Man movie wears. That would do me.

    --
    "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
  48. Ambulance chasers galore by Anonymous Coward · · Score: 0

    Yeah - the main problem will be knee injuries - there are enough dumbasses around that can't control a car in 2d..
    On the other hand it's rather costly and injuries should be deadly in a good proportion of cases - might actually get rid of a bunch of lawyers that way.

  49. Re:More (better) info on jetpacks by Anonymous Coward · · Score: 0

    That's a nice article. Thanks.

  50. Re:More (better) info on jetpacks by bill_mcgonigle · · Score: 1

    http://depletedcranium.com/?p=103

    Surely you tried promoting it beyond Slashdot? I only see one link to it on Google.

    --
    My God, it's Full of Source!
    OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
  51. Re:Jetpacks are just a bad idea, just like sprawl by The+FNP · · Score: 1

    Not to be a Troll, but every thing you say except for the lebensraum(more later) is a self-perpetuating cycle that is entirely a result of the American idea of entitlement(i.e. "Me and My kids are entitled to have the perfect life with no contact with reality").

    The "White Flight" as it is occasionally known results in significant urban sprawl, economic stratification, abject poverty in the city center, increased strain on mass transit, depressed downtown economies, etc. And it doesn't solve any problems, it just results in an ever increasing commute time.

    The method that cities use to survive and maintain their tax base is called annexation. The City expands its borders, recapturing the people who have moved to the suburbs, regaining its tax base(in some cases increasing it). Then the cycle repeats, people don't like living "in the city" so they move another 10 - 20 minutes away, and are annexed in the next round.

    As far as the elbow room you crave, there are choices between an urban apartment and a horse farm in the country. I understand wanting a back yard, and even though I live downtown, I have one. I wanted to have room for a garden, and wanted to have a neighborhood where I knew my neighbors, but I could still easily walk to the city center. I'm perfectly happy where I am, I've been there for years, and have no intention of moving.

    --The FNP

  52. Dragonfly Pack? by sanman2 · · Score: 1

    I wouldn't mind something like a "dragonfly pack" so that we could fly around like Tinkerbell. Perhaps with enough wingbeats per second, it could dynamically adjust to instabilities caused by the movement of your body, etc.

    1. Re:Dragonfly Pack? by thePowerOfGrayskull · · Score: 1

      Just need fairydust for that... that's about the only way I could think of to contain enough energy at light enough weight to move wings capable of displacing enough air..

  53. I can't wait! by wcrowe · · Score: 1

    I can't wait to get my jet pack. Hobnobbing with Howard Hughes, fighting Nazis, and best of all, dating Jennifer Connelly. That's the life for me!

    --
    Proverbs 21:19
  54. Think of the horses!! by Cybrex · · Score: 1

    Can you imagine the panic that internal combustion engines, with their infernal racket and belching smoke, would induce in horses and other beasts of burden! It would be pandemonium in our streets! Bedlam! They're surely just a fad, but this nonsense must nevertheless be nipped in the bud. Ban horseless carriages now, before they become a scourge to our society!

    --
    Boundless Expansion, Self-Transformation, Dynamic Optimism, Intelligent Technology, Spontaneous Order- BEST DO IT SO!
  55. Re:Jetpacks are just a bad idea, just like sprawl by cayenne8 · · Score: 1
    "Not to be a Troll, but every thing you say except for the lebensraum(more later) is a self-perpetuating cycle that is entirely a result of the American idea of entitlement(i.e. "Me and My kids are entitled to have the perfect life with no contact with reality")."

    But, what are you going to do? It is a free country...and lots of open land out there. And, when an area starts going 'downhill'....when poverty and crime starts creeping closer, it is natural for people of means to try to move away from it.

    --
    Light travels faster than sound. This is why some people appear bright until you hear them speak.........
  56. Re:Jetpacks are just a bad idea, just like sprawl by The+FNP · · Score: 1
    I was implying that people should attempt to fix the underlying problems rather than succumbing to "somebody else's problem" syndrome.

    Anyhoo . . . not likely to happen anytime soon, but we can hope, right?

    --The FNP