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Jet pack, rocket belt, rocket pack and similar names are used for various types of devices, usually worn on the back, that are propelled by jets of escaping gases (or in some cases water) to let a single user propel themselves into the air or fly.
The concept emerged from science fiction in the 1920s and became popular in the 1960s as the technology became a reality. The most common use of the jetpack has been in extra-vehicular activities for astronauts. Despite decades of advancement in the technology, the challenges of Earth's atmosphere, Earth's gravity, and the human body not being adapted to fly naturally, remain an obstacle to its potential use in the military or as a means of personal transport. As the human body is not naturally meant to fly, the jetpack must accommodate for all factors of flight such as lift and, to some extent, stabilization.
The first jet pack was developed in 1919 by the Russian inventor Aleksandr Fyodorovich Andreyev. The project was thought-of highly by Nikolai Rynin and technology historians Yu. V. Biryukov and S. V. Golotyuk. Later it was issued a patent but apparently was not built or tested. It was oxygen-and-methane-powered (likeliest a rocket) with wings each roughly 3 feet long.
A hydrogen peroxide-powered motor is based on the decomposition reaction of hydrogen peroxide. Nearly pure (90% in the Bell Rocket Belt) hydrogen peroxide is used. Pure hydrogen peroxide is relatively stable, but in contact with a catalyst (for example, silver) it decomposes into a mixture of superheated steam and oxygen in less than 1/10 millisecond, increasing in volume 5,000 times: 2 H2O2 → 2 H2O + O2. The reaction is exothermic, i.e., accompanied by the liberation of much heat (about 2,500 kJ/kg), forming in this case a steam-gas mixture at 740 °C (1,364 °F). This hot gas is used exclusively as the reaction mass and is fed directly to one or more jet nozzles.
The great disadvantage is the limited operating time. The jet of steam and oxygen can provide significant thrust from fairly lightweight rockets, but the jet has a relatively low exhaust velocity and hence a poor specific impulse. Currently, such rocket belts can only fly for about 30 seconds (because of the limited amount of fuel the user can carry unassisted).
A more conventional bipropellant could more than double the specific impulse. However, although the exhaust gases from the peroxide-based motor are very hot, they are still significantly cooler than those generated by alternative propellants. Using a peroxide-based propellant greatly reduces the risk of a fire/explosion which would cause severe injury to the operator.
In contrast to, for example, turbojet engines which mainly expel atmospheric air to produce thrust, rocket packs are far simpler to build than devices using turbojets. The classical rocket pack construction of Wendell Moore can be made under workshop conditions, given good engineering training and a high level of tool-making craftsmanship.
The main disadvantages of this type of rocket pack are:
These circumstances limit the sphere of the application of rocket packs to very spectacular public demonstration flights, i.e., stunts, but due to their strong visual impact, rocket pack flights are guaranteed to seize the attention of spectators. As a result, rocket pack flights enjoy great success at major sporting events. For example, a flight was arranged in the course of the opening ceremony of the summer Olympic Games 1984 in Los Angeles, USA.
In 1958, Garry Burdett and Alexander Bohr, Thiokol Corporation engineers, created a Jump Belt which they named Project Grasshopper. Thrust was created by high-pressure compressed nitrogen. Two small nozzles were affixed to the belt and directed vertically downward. The wearer of the belt could open a valve, letting out nitrogen from the gas cylinder through the nozzles, which tossed him upward to a height of 7 meters (22 feet). After leaning forward, it was possible with the aid of the jump belt's thrust to run at 45 to 50 km/h (27 to 31 mph). Later, Burdett and Bohr tested a hydrogen peroxide-powered version. The jump belt was demonstrated by a serviceman in action, but as no financing was forthcoming, there was no further testing.
In 1959 Aerojet General Corporation won a U.S. Army contract to devise a jet pack or rocket pack. At the start of 1960 Richard Peoples made his first tethered flight with his Aeropack.
In 1960, the Bell Rocketbelt was presented to the public. The jet of gas was provided by a hydrogen peroxide-powered rocket, but the jet could also be provided by a turbojet engine, a ducted fan, or other kinds of rockets powered by solid fuel, liquid fuel or compressed gas (usually nitrogen).
The US military did not lose interest in this type of flight vehicle. Transport studies of the U.S. Army Transportation Research Command (TRECOM) determined that personal jet devices could have diverse uses: for reconnaissance, crossing rivers, amphibious landing, accessing steep mountain slopes, overcoming minefields, tactical maneuvering, etc. The concept was named "Small Rocket Lift Device", SRLD.
Within the framework of this concept the administration concluded a big contract with the Aerojet General company in 1959 to research the possibility of designing an SRLD suitable for army purposes. Aerojet came to the conclusion that the version with the engine running on hydrogen peroxide was most suitable. However, it soon became known to the military that engineer Wendell Moore of the Bell Aerosystems company had for several years been carrying out experiments to make a personal jet device. After becoming acquainted with his work, servicemen during August 1960 decided to commission Bell Aerosystems with developing an SRLD. Wendell Moore was appointed chief project engineer.
This is the oldest known type of jet pack or rocket pack. One Bell Rocket Belt is on display at the Smithsonian Institution's National Air and Space Museum annex, the Steven F. Udvar-Hazy Center, located near Dulles Airport.
The Bell Pogo was a small rocket-powered platform that two people could ride on. Its design used features from the Bell Rocket Belt.
More commonly known as "The Rocketman", Powerhouse Productions, owned and operated by Kinnie Gibson, is the first company to manufacture the 30 second flying Rocketbelt (June 1994) and to exclusively organize Rocketbelt performances. Since 1983 Powerhouse Productions has performed show flights in over 40 countries such as the Carnival in Rio de Janerio, Super Bowls, the Rose Parade, Daytona 500, and the Michael Jackson Dangerous World Tour, as well as many television shows including Walker Texas Ranger, The Fall Guy and NCIS. Powerhouse Rocketbelt pilots include stuntman Kinnie Gibson and Dan Schlund.
The Tecaeromex Rocket Belt is made by the OathKeeper Inc. Company, run by its vice president, Clayton Bruce Reed Tecnologia Aeroespacial Mexicana. This is said to be the only company in the world offering a flying and tested rocket belt package. It was featured in the March 2006 issue of Popular Science magazine and many TV programs around the world like the Discovery Channel, the BBC, ProSieben, TV Azteca, The Science Channel, and The History Channel. Its maker claims that four of his rocketpacks are flying now; his first tethered flights were on 22 September 2005.
On August 11, 2006, the inventor's daughter, Isabel Lozano, was the first woman in the world to fly tethered in a rocket belt in front of millions of TV spectators; she flew with a special rocket belt built by Tecnologia Aeroespacial Mexicana (TAM). It runs on hydrogen peroxide and sells for USA $125,000 including a training course.
They use hydrojet packs when training pilots to use their jetpacks.
This jetpack manufacturer is still active as at December 2014.
Christian Stadler from Germany organized the first international wingsuit competition to feature a monetary prize, in 2005, called "SkyJester's Wings Over Marl". His "VegaV3 wingsuit system" uses an electronically adjustable hydrogen peroxide rocket. The rocket provides 1000 Newtons (100 kgf) of thrust, and produces no flames or poisonous fumes. His first successful powered wingsuit jump was in 2007, when he reached horizontal speeds of over 255 km/h (160 mph).
Jetpack International made three types of wingless jet packs:
|Name||Max flight time||Max distance||Max speed||Max height||Max pilot weight||Fuel||Motor type||Fuel capacity||Price|
|Jet pack H202||23 seconds||152 m (498 ft)||112 km/h (69 mph)||37 m (121 ft)||81 kg (178 lb)||hydrogen peroxide||rocket||22 litre (5.8 gallons)||Not for sale|
|Jet pack H202-Z||33 seconds||457 m (1,499 ft)||124 km/h (76 mph)||76 m (249 ft)||81 kg (178 lb)||hydrogen peroxide||rocket||30 litre (7.9 gallons)||Not for sale|
|Jet pack T-73||~9 minutes||c. 18 km (11 miles)||~134 km/h (83 mph)||~76 m (249 ft)||81 kg (178 lb)||Jet-A fuel||T-73 jet motor||19 litre (5 gallons)||$200,000|
A Jet Pack H202 was flown for 34 seconds in Central Park on the 9 April 2007 episode of the Today Show and sold for $150,000. As of January 2009 their H202 jet packs are for demonstration only, not for sale. Details of the likely consumer model "Falcon" were scheduled for an official announcement on May 1, 2012, but the company is currently behind schedule.
This jetpack manufacturer is still active as at December 2014.
According to the U.S. Government, real jetpacks have little practical value due to the limitations of current technology. The United States Armed Forces, which conducted most jet pack research, has declared that helicopters are far more practical. Many others have worked on devising a functional jet pack, but with limited success.
In recent years, the rocket pack has become popular among enthusiasts, and some have built them for themselves. The pack's basic construction is rather simple, but its flying capability depends on two key parts: the gas generator, and the thrust control valve. The rocket packs being built today are largely based on the research and inventions of Wendell Moore at Bell Helicopter.
One of the largest stumbling blocks that would-be rocket pack builders have faced is the difficulty of obtaining concentrated hydrogen peroxide, which is no longer produced by many chemical companies. The few companies that produce high-concentration hydrogen peroxide only sell to large corporations or governments, forcing some amateurs and professionals to set up their own hydrogen peroxide distillation installations. High-concentration hydrogen peroxide for rocket belts was produced by Peroxide Propulsion (Gothenburg, Sweden) from 2004 to 2010, but after a serious accident Peroxide Propulsion stopped making it.
Packs with a turbojet engine are fueled with traditional kerosene-based jet fuel. They have higher efficiency, greater height and a duration of flight of many minutes, but they are complex in construction and very expensive. Only one working model of this pack was made; it underwent flight tests in the 1960s and at present it no longer flies. Jet packs and rocket packs have much better flight time on a tankful of fuel if they have wings like an aeroplane's.
In 1965 Bell Aerosystems concluded a new contract with the Defense Advanced Research Projects Agency (DARPA) to develop a jet pack with a turbojet engine. This project was called the "Jet Flying Belt", or simply the "Jet Belt". Wendell Moore and John K. Hulbert, a specialist in gas turbines, worked to design a new turbojet pack. Williams Research Corporation (now Williams International) in Walled Lake, Michigan, designed and built a new turbojet engine to Bell's specifications in 1969. It was called the WR19, had a rated thrust of 430 pounds of thrust (195 kgf, 1,910 newtons) and weighed 68 pounds (31 kg). The Jet Belt first flew free on 7 April 1969 at the Niagara Falls Municipal Airport. Pilot Robert Courter flew about 100 meters in a circle at an altitude of 7 meters, reaching a speed of 45 km/h. The following flights were longer, up to 5 minutes. Theoretically, this new pack could fly for 25 minutes at velocities up to 135 km/h.
In spite of successful tests, the U.S. Army lost interest. The pack was complex to maintain and too heavy. Landing with its weight on their back was hazardous to the pilot, and catastrophic loss of a turbine blade could have been lethal.
Thus, the Bell Jet Flying Belt remained an experimental model. On 29 May 1969, Wendell Moore died of complications from a heart attack he had suffered six months earlier, and work on the turbojet pack was ended. Bell sold the sole version of the "Bell pack", together with the patents and technical documentation, to Williams Research Corporation. This pack is now in the Williams International company museum.
The "Jet Belt" used a small turbofan engine which was mounted vertically, with its air intake downward. Intake air was divided into two flows. One flow went into the combustion chamber, the other flow bypassed the engine, then mixed with the hot turbine gases, cooling them and protecting the pilot from the high temperatures generated. In the upper part of the engine the exhaust was divided and entered two pipes which led to jet nozzles. The construction of the nozzles made it possible to move the jet to any side. Kerosene fuel was stored in tanks beside the engine. Control of the turbojet pack was similar to the rocket pack, but the pilot could not tilt the entire engine. Maneuvering was by deflecting the nozzles. By inclining levers, the pilot could move the jets of both nozzles forward, back, or sideways. The pilot rotated left/right by turning the left handle. The right handle governed the engine thrust. The jet engine was started with the aid of a powder cartridge. While testing this starter, a mobile starter on a special cart was used. There were instruments to control the power of the engine, and a portable radio to connect and transmit telemetry data to ground-based engineers. On top of the pack was a standard auxiliary landing parachute; it was effective only when opened at altitudes above 20 meters. This engine was later the basis for the propulsion units of Tomahawk and other cruise missiles.
Jetpack International makes or made a wingless turbojet pack: see #Jetpack International above.
On 25 October 2005 in Lahti in Finland, Visa Parviainen jumped from a hot air balloon in a wingsuit with two small turbojet jet engines attached to his feet. Each turbojet provided approximately 16 kgf (160 N, 35 lbf) of thrust and ran on kerosene (Jet A-1) fuel. Parviainen apparently achieved approximately 30 seconds of horizontal flight with no noticeable loss of altitude.
Swiss ex-military and commercial pilot Yves Rossy developed and built a winged pack with rigid aeroplane-type carbon-fiber wings spanning about 8 feet (2.4 m) and four small kerosene-burning jet engines underneath; these engines are large versions of a type designed for model aeroplanes. He wears a heat-resistant suit similar to that of a firefighter or racing driver to protect him from the hot jet exhaust. Similarly, to further protect the wearer, the engines are modified with the addition of a carbon fibre heat shield extending the jet nozzle around the exhaust tail.
Rossy claims to be "the first person to gain altitude and maintain a stable horizontal flight thanks to aerodynamic carbon foldable wings", which are folded by hinges at their midpoint. After being lifted to altitude by a plane, he ignites the engines just before he exits the plane with the wings folded. The wings unfold while in free-fall, and he is then able to fly horizontally for several minutes, landing with the help of a parachute. He achieves true controlled flight using his body and a hand throttle to maneuver.
The system is said by Rossy to be highly responsive and reactive in flight, to the point where he needs to closely control his head, arm and leg movements in order not to enter an uncontrolled spin. The engines on the wing require precise common alignment during set-up, also in order to prevent instability. An electronic starter system ensures that all four engines ignite simultaneously. In the event of a spin, the wing unit can be detached from the pilot, and both pilot and wing unit descend to Earth on separated parachutes.
Rossy's jet pack was exhibited on 18 April 2008 on the opening day of the 35th Exhibition of Inventions at Geneva. Rossy and his sponsors spent over $190,000 to build the device. His first successful trial flight was on 24 June 2004 near Geneva, Switzerland. Rossy has made more than 30 powered flights since. In November 2006 he flew with a later version of his jet pack. On 14 May 2008 he made a successful 6-minute flight from the town of Bex near Lake Geneva. He exited a Pilatus Porter at 7,500 feet (2,300 m) with his jet pack. It was the first public demonstration before the world's press. He made effortless loops from one side of the Rhone valley to the other and rose 2,600 feet (790 m).
It has been claimed that the military was impressed and asked for prototypes for the powered wings, but that Rossy kindly refused the request stating that the device was only intended for aviation enthusiasts.
On 26 September 2008, Yves successfully flew across the English Channel from Calais, France to Dover, England in 9 minutes, 7 seconds. His speed reached 186 mph (299 km/h) during the crossing, and was 125 mph (201 km/h) when he deployed the parachute. Since then he has—in several flights—managed to fly in a formation with three military jets and cross the Grand Canyon, but he failed to fly across the Strait of Gibraltar—he made an emergency landing in the water.
In 2008 Troy Hartman started designing a wingless jetpack with two turbojet motors strapped to his back.
As at 2013 Fritz Unger in Germany is developing a jetpack called Skyflash with rigid wings about 3.4 meters or 11 feet wingspan and two turbojets designed to run on diesel fuel. It is designed for takeoff from the ground using four undercarriage wheels on the front of his chest and abdomen.
Rocket packs can be useful for spacewalks. While near Earth a jet pack has to produce a g-force of at least 1g (a smaller g-force, providing only some deviation from free fall is of little use here), for excursions outside a free falling spaceship, a small g-force providing a small deviation from free fall is quite useful. Hence much less delta-v is consumed per unit time, and not during the whole EVA. With only small amounts of thrust needed, safety and temperature are much more manageable than in the atmosphere in Earth's gravity field.
Nevertheless it is currently worn to be used only in case of emergency: the Simplified Aid for EVA Rescue (SAFER).
Episode 32 of MythBusters investigates the urban legend of an affordable jet pack or rocket pack that can be built from plans purchased on the Internet. Extensive modifications were made by the MythBusters team due to vagueness in the plans and because of the infeasibility of the specified engine mounting system. The jet pack produced by the MythBusters had two ducted fans powered by ultralight-type piston engines. (Fans[who?] complained that the use of piston engines destroyed the whole idea of the pack's being truly based on jets, by which, presumably, they meant self-contained gas turbines.) They found it was not powerful enough to lift a person off the ground, and was expensive to build. The plans specified a Rotax 503 ultralight engine, but they intended to use the more powerful and lighter Rotax 583 engine before a similar lighter unnamed engine was substituted.
The concept of jet packs appeared in popular culture, particularly science fiction long before the technology became practical. Perhaps the first appearance was in pulp magazines. The 1928 cover of Amazing Stories featured a man flying with a jet pack.
When Republic Pictures planned to do a superhero serial using its renown "flying man" scenes as used in The Adventures of Captain Marvel, the character of Captain Marvel was tied up in litigation with the owners of the character of Superman. For its postwar superhero serial, Republic used a jet pack in King of the Rocket Men. The same stock special effects were used in other serials.
While several science fiction novels from the 1950s featured jetpacks, it was not until the "Bell Rocket Belt" in the 1960s that the jet pack caught the imagination of the mainstream. Bell's demonstration flights in the U.S. and other countries created significant public enthusiasm.
Jetpacks were featured in two episodes ("Turu the Terrible" and "The Invisible Monster"), of the original Jonny Quest (1964-1965) animated television series, and are seen at the end of the closing credits.
In 1965 a jetpack appeared in the James Bond movie Thunderball when 007 played by Sean Connery used a jet pack in the pre-title sequence to escape the bad guys and rendezvous with his French contact. The pack was piloted by Gordon Yaeger and Bill Suitor. The jet pack had a brief cameo in Die Another Day. In the same year of 1965 it appeared in the pilot episode of Lost in Space with jet pack stock footage appearing in the television series several times. The jet pack from Thunderball was also featured, though somewhat anachronistically, in the 2005 video game adaptation of From Russia With Love.
A rocket pack flight famously occurred on the opening of the summer Olympic Games in Los Angeles in 1984, piloted by Bill Suitor, who landed opposite the presidential platform, where Ronald Reagan sat.
On April 28, 2008, at a pre-screening premiere for the movie Iron Man, the Alamo Drafthouse in Austin, Texas had Go Fast jetpack pilot Eric Scott dressed as Iron Man where he flew around the lot in front of the theater.
Jetpacks appear in the popular video game Halo: Reach. On September 13, 2010, during a Halo: Reach launch party at London, England's Trafalgar Square, stuntman Dan Schlund of Powerhouse Productions Inc "Rocketman" firm (which provides jet packs for use by marketing and sporting companies) donned a Halo-esque "Spartan armor" suit and a jet pack and maintained flight for 30 seconds before landing safely. The jet-pack also appears in the 2012 video game Halo 4, developed by 343 Industries.
Jetpacks also appeared in other video games, including BloodRayne (worn by Nazi troopers), Tribes, Giants: Citizen Kabuto, Armed and Dangerous, and the Pilotwings series, in which it is referred to as a "Rocket Belt". It is also accessible in the video game Grand Theft Auto: San Andreas.
A rocket pack was used to deliver the game ball at the 2011 University of Michigan vs. Purdue University football game in Ann Arbor, Michigan. The pack was piloted by Eric Scott and powered by hydrogen peroxide.
NCIS: Season 7, Episode 11 "Ignition". An investigation into the death of an aviator and an experimental jet pack is hindered by a lawyer who appears to have a vendetta against NCIS. Agent Timothy McGee is also revealed to have an obsession with jetpacks and jetpack technology.
The 21st century has seen a new approach to jet packs where water is used as a high-density propulsion fluid. This requires a very large mass of fluid that makes a self-contained jetpack infeasible. Instead, this approach separates the engine, fuel and fluid supply from the pilot's flying apparatus, using a long flexible hose to feed the water to the jet nozzle pack attached to the pilot's body. These inventions are known as "hydro jet packs", and successful designs have used jetski technology as the powerplant operating in a body of water (the ocean, a lake or a pool) to provide the needed propulsion. Several hydro jet pack approaches have been successfully tested and put into production. Flow rate can be controlled by a throttle operator on the jetski, or by the pilot using a remote actuator.
Another significant difference with hydro jet packs is that they can be operated below the surface as well as above it. As of 2013, many hydro jet pack rental businesses are operating in various locations around the world.
Zapata Racing, led by Franky Zapata, is a company that makes hydrojet packs. It uses a simplified design called the Flyboard, with the two primary water jets under each of the pilot's feet. An optional feature is a lower-thrust water jet for each arm for greater control. The powerplant is a regular jetski, with simple modifications. Development for this approach was started in the Spring of 2011. Their 2013 model, FlyBoard V2, has a control cable running inside of the water hose enabling the pilot to actuate the throttle. As one example of pricing, the 2013 Flyboard is being sold in the US as a kit for about $6,000 (not including jetski).
Around this time, a Russian fellow identifying himself as A. Andreev filed a patent for an oxygen- and methane-fueled flying device that could be worn on the back, with roughly three-foot wings extending to either side of the hopeful pilot... "This is the first device of its kind that had any engineering detail at all,"...
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