It’s 2007 and WHERE IS MY JETPACK?!?!?!

September 10th, 2007
submit to reddit Share

Where is my damn jetpack? I mean seriously! It’s 2007! Weren’t we all supposed to be flying around in these in the future, as predicted in the 1950’s and 1960’s? Technology has progressed by leaps and bounds in the past few decades and still NO JETPACK!

Sure there are other personal flying devices like ultralights and powered paragliders, but I want a jetpack!

The whole idea of a jetpack is like the Zen of flying machines. A manageably-sized, easy to fly, light-weight, safe pack which you can strap on and go off for a flight to the supermarket or to work or for just a bit of sightseeing. You land your jetpack where you want and then simply walk inside and leave the pack next to your desk.

When the days out, you strap it on and head outside. You might pick up a newspaper, which you stick in the jetpacks side pocket, and then extend the controller arms, grab the stick, step politely away from anyone who might get disheveled by the jetwash and then fire it up and take off for home.

Why don’t we have those? Well, there are some reasons. Jetpacks have been built and are not totally fictional. They do work, but getting one with adequate range and size is a tough nut to crack.

To be a true, usable, practical “jet pack , like is seen in the movies the device must meet some basic criteria: Be of manageable weight, no more than a couple hundred pounds at the very most, and ideally much less. Have good endurance of approximately 35-45 minutes, at the very least. Be able to product enough thrust to lift itself, its pilot and still have enough left over to maneuver. Be relatively safe and easy to use.

Can it be done? Maybe. To understand, lets take a look at the history of backpack flight.

In the beginning

The Bell Corporation began developing the concept of a jetpack, or as it was called, a “flying belt as early as the late 1950′s. Although earlier attempts had been made, this was the first serious effort at a wearable flying device. With funding from the military, the project produced its first workable prototypes in the 1961.

The first successful “flying belt, was the Bell Rocketbelt, a relatively simple, strap-on flying backpack powered by hydrogen-peroxide rockets. It was relatively easy to fly, had plenty of power for lifting and maneuvering, good controls and was reasonably sized with manageable weight. It seemed like the perfect starting point and proof of concept. However, it also only could fly for about 22 seconds before the fuel tanks ran dry.

Additionally, the fact that it ran on 90% concentration hydrogen peroxide could be a bit of a concern. The system decomposed hydrogen peroxide on a catalytic grid to make high pressure steam for thrust, and although this was a simple and effective means of propulsion, the peroxide could eat human flesh down to the bone if it were accidentally spilled or the tanks ruptured. Due to these limitations, the army was rather disappointed and saw little potential for the rocketbelt, with the project ending in 1969.

This type of device is actually still around today, and newer versions have pushed the flight time up to 30 seconds (by enlarging the fuel tanks). The rocket belt is commonly used for exhibitions and movie and television stunts. With good editing and camera changes, its 30 seconds of flight time can be made to look like much more, but practical uses beyond entertainment are limited by the very short flight time. One of the most notable appearances was in the 1984 Olympic Games’ opening ceremony.

Enter the jet engine

 

The limitations of a rocket-based system were apparent from the beginning. Although the rocket engines provided a small, controllable and high power means of thrust, rocket engines are hardly fuel-efficient. Rocket engines are most efficient for uses which require very high speed and relatively short durations of use. For a device like a flying belt or pack, they are not a very good solution.

Thus focus at Bell quickly shifted to creating a system using a more efficient air-breathing jet engine. This culminated with the first working Jet Belt prototype in 1969. The system was powered by a Williams International WR-19 micro-turbofan engine, the same jet engine which would go on to become the mainstay of cruise missile propulsion for the military. The jet engine runs most efficiently on high grade kerosene-based jet fuel, but can burn almost anything from regular unleaded to diesel fuel to alcohol.

The Jet Belt did achieve it’s goal of better endurance, with flight times ranging from about 25 minutes all the way up to 40 minutes, depending on fuel load and how much maneuvering was done. However, it did have some shortcomings. For one thing, the pack weighed a good 300-400 pounds, depending on how much fuel was carried. This hardly made it a practical “wearable pack that one could walk around with and necessitated an external stand to bare the weight when the pilot strapped it on.

The performance was decent, but left much to be desired. Although it did have enough power to fly, it was still somewhat underpowered, making it sluggish in climbing and maneuvering when compared to the rocket-based systems. To achieve stability and control, the jet engine was mounted with the intake facing downward and the thrust channeled through two U-shaped ducts which did not help efficiency and made an already loud jet engine even louder.

Additionally, major safety concerns existed. Aside from having scorching hot jet exhaust blowing just a foot and a half from the pilots head, the single jet engine was less than 100% reliable and unlike aircraft, which have some glide ability or helicopters, which can use the inertia of their spinning blades and the principal of autorotation to make an emergency landing, if the engine were to seize up or flame out, the jet pack and pilot would drop like a stone. A rapid-deployable parachute was therefore an important part of the system, but at altitudes of less than 180-200 feet, it would be of little use. Pilots reported that flying in close quarters with obstructions, such as wires was extremely dicey, as wires were very difficult to see when flying at a high rate of speed.

Despite showing some promising results for a feasible jetpack, the project died as funding dried up in the 1970’s.

 

Alternative ideas:

The Williams X-Jet: Williams International, a company well known for pioneering work in microjet engines and the maker of the engine that powered the Jetbelt took the concept a bit further with the experimental X-Jet. Dispensing with the backpack design and adding greater fuel capacity and a slightly larger engine, the prototype was dubbed the “Flying pulpit and could fly for a solid 45 minutes with good maneuverability and speed. However, the X-Jet never went into production, as it was seen as having little commercial potential, given the competition from conventional helicopters. But it still looks like a lot of fun.

Ducted Fans: In theory, a ducted fan based system could achieve much greater efficiency and therefore endurance than a jet engine. The reason is that large diameter fans more a greater volume of air but do so at a lower velocity. Compared to a jet engine, which moves less air, but does so at a much higher pressure and velocity, the approach is considerably more efficient for low-speed and lift applications.

Although a few concept designs have been made, and the principal has been shown workable on full-sized aircraft, there are no known successful ducted fan packs which are airworthy. However, internet sites do sell plans for a ducted fan based flying pack. But when investigated by the Mythbusters, the design failed to do much more than shake and rattle.
Of course, if a ducted fan pack were created, the size of the fans would make it a far cry from the dreams of a “true jetpack

 

Helicopter Packs: Another approach has been to use a helicopter-based backpack as a means of creating a personal flying device. Small one-man helicopters have been built and the concept of strapping such a machine to one’s back is not beyond the realm of possibility, but only limited success has been achieved in creating a stable and safe system based on this arrangement. It seems that the jetpack design offers few advantages over a more conventional layout.

Winged Jetpacks:Adding wings to a jetpack would, in theory, improve efficiency for horizontal flight. The addition of wings would generate some aerodynamic lift, reducing the need for jet thrust alone to maintain flight. However, this does have a major problem: jet packs do not fly like superman. They fly relatively vertically, because a prone position would lead to the pilot’s legs hanging down haphazardly. Only at very high speeds would there be enough air velocity to keep the legs elevated. Just try holding up your legs while your upper body is supported by a bed or table. Also, the addition of wings would increase size.

The only successful uses of winged jetpacks have been by skydivers, where the wings act mostly as a glider, helping to achieve control and gliding while falling from an aircraft. The small jets allow for greater velocity and maneuvering, but do not actually make the setup capable of sustained flight.

 

The Future of Jetpacks:

While the development of jetpacks has been relatively dead since the 1970’s, technology in applicable fields has progressed rapidly. Is it possible that a true usable, reliable, workable jetpack could be in the future? Maybe. Possibly.

What a new jetpack might be like:
(Pure speculation, but based on current technology)

Materials:
With weight such a constant concern, a modern jetpack would most certainly be built out of composite materials, with a thin shell made out of carbon fiber or something similar and a frame made out of similar composites or possibly tubular titanium alloy. The basic frame and shell would weigh as little as a few pounds.

Control:
The inefficiencies and complications of the ducting system could possibly be alleviated by an active control system, which would keep the platform stable and adjust the thrust and thrust vectoring by using sensors such as piezoelectric gyroscopes. The Segway has shown that

active stabilizing systems are feasible for small platforms. Modern use of fly by wire systems have proven them to be robust and reliable. For such a critical system, there would need to be built in redundancy, with uninterrupted power, multiple gyroscopic sensors and simple failsafe logic systems which could take over in a system failure. With modern electronics, this could easily fit on a small circuit board.

Navigation and Collision Avoidance:
The dangers of wires or other obstacles can likewise be addressed by easily available electronics. GPS and a stored database could help store known hazards and wires can be detected by optical sensors, LIDAR or simple radar rangefinders, like those used in police radar guns. A helmet-mounted or goggle display can give such warnings and, if necessary, the electronic control system could force the unit to slow down or climb if it is headed toward a collision.

The benefits of such technology goes beyond avoiding wires or other hazards, however. Modern electronics would allow pilots to fly at low levels safely and without needing to devote all their attention to avoiding hazards. Communications and navigation systems could allow for enhanced safety and prevent becoming lost or disoriented.


Safety if the engine fails:

Modern ballistic parachutes are effective even at low altitudes.

If the altitude is so low that a parachute may not be effective, yet high enough to cause serious injury, ejection seat technology may be useful. Modern ejection seats can function even if the aircraft is very near the ground, by employing small short-burn solid fueled rockets to achieve the necessary altitude and to clear the aircraft. Such technology could be added to the jetpack.

Additionally, if it were possible to add a second engine unit, this may allow for enough thrust for a safe landing. Although it would be lopsided electronic thrust vectoring could help counteract the inherent stability issues.

The Engine:
Since the time of the Bell Jetbelt, microjet technology has progressed greatly. The latest incarnation of the technology is the Williams International EJ22, which is currently in development and which has, unfortunately, been postponed from commercial deployment due to production delays and loss of a contract with Eclipse Aviation.

The prototype of the EJ22 weighs only 85 pounds but can produce 750 pounds of thrust! It reportedly is also one of the most efficient small engines ever developed. It may be possible to scale this engine down even further or to optimize it’s efficiency for lower thrust needs.

The most efficient modern jet engines for low to medium speed use are high bypass turbofan engines. Such engines achieve high efficiency by using the jet turbine to turn an outer fan turbine, which essentially works as a ducted fan. By doing this, the engines are able to move a larger volume of air, and therefore do not need move the air at as high a rate of compression or velocity as a turbojet would. And by mixing the air, the air coming out is not necessarily as scorchingly hot. Modern jets are also quieter

Using dual turbofan engines, made up of large fan compressors and relatively small combustion chambers may be able to achieve higher efficiency than other means. This also offers possible safety benefits as mentioned above.

With adequate funding and development, a safe and practical jet pack may be in the future. But then again, that has been said many times before

 

 

 

 

Links/Sources:
Williams International – Makers of microturbofan engines.
Peroxide Propulsion – Sells hydrogen peroxide and modern rocketbelt units.
Jetpack International – Sells rocketbelt units and claims to have a turbojet engine under development.
Roketbelt Technologies – Yet another manufacturer of a modern derivative of the original rocketbelt system.
Rocketman – A guy who does exhibitions using with rocketbelt system.
Flying Contraptions
– Info on the rocketbelt, jetbelt and other aircraft.
Popular Mechanics Article – Info on recent rocketbelt shows and developments.
Bell Rocket Belt Info – Historical info on the Bell Rocketbelt.
The Rocketbelt Caper- Information about a strange incident where some guys built some rocketbelts and then one got murdered.
Unread Aircraft – More info on the Jetbelt.
The RB 2000 – An updated Rocketbelt design that has larger tanks and can get a few seconds more flight.
Imperfect Ideas – Much good info on the development of the original rocketbelt and the jetbelt.
The Most Comprehensive Website on Rocket and Jet Belts – The name pretty much says it all…

Skywalker Jet – An article about a guy who strapped a bunch of large model-aircraft jet engines together to make a pack of sorts. I have spoken with some amateur jet engine builders and engineers who referred to the guy as a complete idiot. Not surprisingly, the official website is now down.

Also, info from Wikipedia is available via the links embedded in the post…


This entry was posted on Monday, September 10th, 2007 at 2:22 pm and is filed under Culture, Good Science, History. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
View blog reactions



26 Responses to “It’s 2007 and WHERE IS MY JETPACK?!?!?!”

  1. 1
    Joseph Hertzlinger Says:

    At least, we have robotic vacuum cleaners, a computer as chess grandmaster, dental implants (teeth bonded to the bone were only seen in Isaac Asimov’s science fiction a few decades ago), and even a decline in the total number of deaths. We’re getting there.


    Quote Comment
  2. 2
    Jukka Laurila Says:

    And then there’s this guy.

    http://www.metacafe.com/watch/468993/jetman/


    Quote Comment
  3. 3
    Complexity Says:

    1/10


    Quote Comment
  4. 4
    Jamilla Says:

    There already are jetpacks… http://www.youtube.com/watch?v=2gcurwcPs3U


    Quote Comment
  5. 5
    drbuzz0 Says:

    You didn’t read this did you Jamilla? That’s not even a “jetpack” that’s a hydrogen-peroxide rocket system which is discussed above.


    Quote Comment
  6. 6
    towlie Says:

    I think the real question should be where’s my flying car !
    I cant be alone in thinking when i was younger that by the year 2007 we would all be flying around in flying cars why has no one thrown there hat over the wall !


    Quote Comment
  7. 7
    Morder Says:

    Towlie – I don’t want the same person who cuts me off on the road to cut me off in mid-air or someone to cause a simple fender-bender a few hundred feet above my house. I hope we never have flying cars for those reasons alone.

    That said a personal jetpack would be nice


    Quote Comment
  8. 8
    Simply Simple Says:

    Not to mention the green issue, you think your current car is expensive to fuel, think how much a flying car would cost to fuel. I’d love a go on a Jetpack (or similar) but I don’t think they are really that efficient, or a successfull answer to getting people somewhere safely. “Police to cut crack down on drink-flying” is not a headline I ever want to see. Partly because drunk people would be flying above me everywhere, and partly because it would make christmas even more tedious than it already is.


    Quote Comment
  9. 9
    drbuzz0 Says:

    Well the green issue is something, but you could say the same about jetskis or any other use of fuel which is totally for entertainment and not really needed. Burning a few gallons of jet fuel for the purpose of flying around on a jetpack is not, strictly speaking, the most economical or ecological use of energy.

    But come on.. you gotta live a little, right? I’d totally be willing to plant a lot of trees to offset the co2 or otherwise do something to make it more palatable, but considering the amount of fuel wasted on unnecessary things, a jet pack would still be worth it. I mean.. it is a *jetpack*


    Quote Comment
  10. 10
    h Says:

    saw this on /. today. good overall article, but you need to do some edits. “more”?
    also – you’ve missed several helicopter innovations that have been around a long long time!

    http://www.gen-corp.jp/GENH-4_en/
    http://youtube.com/watch?v=wd99ziWFF7Q
    http://www.newlaunches.com/archives/the_worlds_smallest_one_person_helicopter.php
    http://www.acecraftusa.com/

    h

    The reason is that large diameter fans more a greater volume of air but do so at a lower velocity


    Quote Comment
  11. 11
    Jecel Assumpção Jr Says:

    I’ll get to the jet pack after I finish giving good computers to the poor children of the world (yes, I know about the OLPC). I have a design for a jet engine with no moving (solid) parts which is optimized for low speeds. This will make the jet pack cheap and a bit safer.

    For most applications the jet pack design with its pendulum equilibrium is ideal, but if you want to be able to do radical manouvers then it would be nice to have the jet engines next to your legs and vectored by moving your feet. Tests in the late 1940s showed that the computer you have for free inside your skull is up to the task of handling such an unstable configuration. Let me find the reference for that…. here it is:

    http://www.howtoadvice.com/Sky-High


    Quote Comment
  12. 12
    djigadget Says:

    Well Jetpack will available , with flying car also :)
    but I think it wont be long

    :)


    Quote Comment
  13. 13
    fdhdbv Says:

            djigadget said:

    Well Jetpack will available , with flying car also :)
    but I think it wont be long

    :)


    Quote Comment
  14. 14
    Neurovore Says:

    As this topic is more than a year old, feel free to disregard this post. However, here is something that you might find interesting…

    There was a ducted fan design that seemed to work pretty well from an engineering standpoint called the Solotrek XFV. However, funding was pulled from the project after the tether to the testing framework got entangled in the rotor blades and caused the vehicle to fall to the ground. This seemed to be a problem with the bad weather and the testing platform rigging rather than any engineering flaws in the design of the Solotrek XFV itself.

    http://rotorcraft.arc.nasa.gov/research/solotrek.html
    http://en.wikipedia.org/wiki/SoloTrek_XFV

    Personally, I doubt that you will ever see anything like personalized flying machines because of legal and liability issues. Many people have trouble piloting craft in two vehicles AKA the automobile, so you can imagine the sorts of stupidity that you would see by adding a third dimension.


    Quote Comment
  15. 15
    drbuzz0 Says:

            Neurovore said:

    As this topic is more than a year old, feel free to disregard this post. However, here is something that you might find interesting…

    There was a ducted fan design that seemed to work pretty well from an engineering standpoint called the Solotrek XFV. However, funding was pulled from the project after the tether to the testing framework got entangled in the rotor blades and caused the vehicle to fall to the ground. This seemed to be a problem with the bad weather and the testing platform rigging rather than any engineering flaws in the design of the Solotrek XFV itself.

    http://rotorcraft.arc.nasa.gov/research/solotrek.html
    http://en.wikipedia.org/wiki/SoloTrek_XFV

    I have seen that thing and the last I saw of it they had it to the point where it had enough power to lift a human but it was not stable when flying at anything above ground effect and had to have people holding onto it to keep it righted correctly. It’s possible that it has since been improved to the point where it’s free-flyable but it sounds like it stopped development

    Here’s the issue with those as far as I see it though: If it’s that large that it actually has to be on its own free-standing system and not a real ‘pack’ then it defeats the purpose. You could just as easily strap yourself to the side of a helicopter and have some external controls so you can fly it while strapped to the outside.

    The point of a jet pack is that it is ‘wearable’ This sets it apart from other small personal ultralight aircraft. There are already small helicopters and such things, but they don’t really fit the bill for a jetpack. A jet pack is wearbale – you can fly around, land with it and then walk a decent distance, interact with someone, then take off again and start flying. That’s the whole point.


    Quote Comment
  16. 16
    ManBearPig Says:

    The sad fact is that the Williams FJ-22 was the bleeding edge in microturbofans and the furthers along in small and light weight with descent performance, but it’s not being developed anymore. It did well in the prototype phase but the big customer was eclipse aviation and they were not impressed with the number of holdups Williams was having in getting it into full production and they dropped the line and that was that for the whole line. I would not put much hope in the jetpack concept being enough to resurect that product. It might come back as a UAV engine or something.


    Quote Comment
  17. 17
    John Says:

    The Treco 301 jet engine can be used for a jet pack it is light and also can be used for a cruise missile looks exactly like the one the girl is holding


    Quote Comment
  18. 18
    Spuffler Says:

    http://www.youtube.com/watch?v=dST-a5IU_h4

    Jet powered wings strapped onto a man.


    Quote Comment
  19. 19
    drbuzz0 Says:

            Spuffler said:

    http://www.youtube.com/watch?v=dST-a5IU_h4

    Jet powered wings strapped onto a man.

    Did you not even bother to look at the article even briefly? That was covered. It’s not anything like a classic jet pack. It’s a skydiving accessory. You can’t take off and fly with it – you have to jump out of a plane and then you glide and the jet engine just gives a little extra push. There’s no ability to remain aloft – it doesn’t have nearly enough lift for that at any reasonable velocity.

    You also can’t land with it. You’re essentially falling with a small amount of aerodynamic control and lift and a jet engine to give you some push. You need to open a parachute to land.

    This is all mentioned above.


    Quote Comment
  20. 20
    ian bennett Says:

    Have a look at this website!

    Ian


    Quote Comment
  21. 21
    DV82XL Says:

    It’s a wonder that with so many amateurs (i.e. non-aerospace) playing with these types of systems, that there hasn’t been more fatalities.


    Quote Comment
  22. 22
    drbuzz0 Says:

            DV82XL said:

    It’s a wonder that with so many amateurs (i.e. non-aerospace) playing with these types of systems, that there hasn’t been more fatalities.

    There are a number of small organizations and individuals who have managed to recreate the Bell Rocketbelt or a new variation of it. This is the only such device that thus far as proven successful. Of course it only provides about 25-35 seconds of usage, but it’s the one that is still used for stunts and commercials and stuff.

    It’s amazing to me nobody has been killed by that thing if only because of the fuel it runs on. It’s powered by hydrogen peroxide. (Not the 3% stuff in your medicine cabinet, this is high test peroxide which is 90%+) If the fuel tank ruptured from a fall or if a line broke that stuff will literally eat right through the human body


    Quote Comment
  23. 23
    Scorn Says:

    The reason we don’t have flying cars and sustained flight back packs is because we using propellers, fans and jet engine tech. Compressed air thrust generated from a smaller motor would have worked if it were develop to attain high pressures. But like a lot of amazing tech back in the day, if it didn’t make use of oil and systems of profit, it was discarded. But now since we burnt off most of the oil guess we can get back to progression. Any takers on the air thrust engine or have we skipped that amazing invention and got something else to make money off?


    Quote Comment
  24. 24
    Engineering Edgar Says:

            Scorn said:

    The reason we don’t have flying cars and sustained flight back packs is because we using propellers, fans and jet engine tech. Compressed air thrust generated from a smaller motor would have worked if it were develop to attain high pressures. But like a lot of amazing tech back in the day, if it didn’t make use of oil and systems of profit, it was discarded. But now since we burnt off most of the oil guess we can get back to progression. Any takers on the air thrust engine or have we skipped that amazing invention and got something else to make money off?

    Compressed air? Sir, surely you are joking. Compressed air is certainly not a lost or undeveloped technology. We can compress air with the systems we have. There is a limit to how much you can compress it though. Eventually with enough compression, all the gasses will liquify. Even then, when you have compressed air down to the point of being a liquid, the amount of energy it stores is pretty poor and it is extremely inefficient.

    It looks like we have a new myth on our hands that is making the rounds. Now compressed air is a super energy storage method. Oh brother!


    Quote Comment
  25. 25
    backpackvaccums.org Says:

    While you have backpack flight, I have something interesting for you too backpack vaccums :)

    http://backpackvaccums.org – This site is dedicated to providing information on backpack vacuums, and related products. What we aim to do is to talk about some of the best vacuums, and then show the current offerings from eBay.


    Quote Comment
  26. 26
    KiwisCanFly Says:

    Time this was updated…

    The Martin Aircraft Company in Christchurch New Zealand have deveiloped and launched a Jetpack.
    How does 30-45minites of flight time and upto 8,000ft sound. Incorporates some flight control AI from Rockwell Colins. Checkout their website for more info…or to book a test flight! http://www.martinjetpack.com

    For Search and Rescue A Martin Jetpack could be sent to recover via remote (UAV mode).

    IMHO I believe this iteration of the jetpack to be the safest, efficient and functional of the differing types developed over the years.

    I plan to fly one next year.


    Quote Comment

Leave a Reply

Current month ye@r day *

Please copy the string 9ddGaY to the field below:

Protected by WP Anti Spam