Flying with a Jet Pack
"Rocket belt", "rocket pack", "jet pack", and similar names, are various types of devices, usually worn on the back, that use jets of escaping gases to allow the user to fly. The concept of these devices evolved from the 1920s when Buck Rogers, science fiction comic strip hero, used a rocket pack for future travel.
In the common modern jet pack, 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: it is a colorless liquid with a density of 1.35 g/cm³. Pure hydrogen peroxide is relatively stable, but in contact with the catalyst (for example, silver) it decomposes into a mixture of superheated steam and oxygen in less than 1/10 millisecond increasing in volume 5000 times: 2 H2O2 = 2 H2O + O2. The reaction is exothermic, i.e. with liberation of much heat (about 2500 kJ/kg), forming in this case a steam-gas mixture at 740 °C. While very hot it is much cooler than other propellants reducing the risk of a fire.
This hot gas is fed into one or more jet nozzles. The great disadvantage is the limited amount of fuel that can be carried. Because the jet of steam is what provides the thrust, the engine has a low specific impulse. The rocket belt not only uses the peroxide as fuel, but also as reaction mass — in contrast to, for example, jet engines which mainly expel atmospheric air to produce thrust. A man's carrying capacity sets an upper bound on weight, and so currently such rocket belts can only fly for about 30 seconds.
(There is no sound on the second one)
Rocket packs are simpler to build than devices using turbojets. The classical rocket pack of the construction of Wendell Moore can be prepared in workshop conditions but needs good engineering training and high level of tool-making craftsmanship. A main fault in the rocket pack is short duration of flight (to 30 seconds) and the high expense of scarce fuel (hydrogen peroxide). These circumstances limit the sphere of the application of rocket packs to very spectacular public demonstration flights. Rocket pack flights typically seize the attention of spectators and enjoy great success. For example, a flight was arranged in the course of the opening ceremony of the summer Olympic Games 1984 in Los Angeles, USA, which can be viewed in the next video:
The movies and information for this target are from: JetPack International
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Many thanks to Ray McClure for the research and developement of this target.