What Is a Jet Pack? Definition, Meaning and Concept
A jet pack is a device someone uses that creates enough thrust, in a system similar to jet engines, to allow them to get off the ground and fly. This flight thrust can be created in a number of ways, although a traditional "jet" uses fuel to power the fans that enable takeoff. Newer versions often use hydrogen peroxide and a catalytic reaction to create a stream of heated vapor that provides thrust. A jet pack is typically an impractical device, as it is not only extremely unsafe but reliant on small supplies of fuel that cannot allow for prolonged flight.
The basic idea behind a jet pack is a self-contained unit that can be used and operated by a single person, allowing the user to fly. In reality, however, this concept has been quite difficult to achieve and even with technological advances it remains impractical. There are a number of different ways a jet pack can be conceived and designed, although it generally includes a rocket pack worn on the operator's back, with different functions and controls for adjusting flight. Most of these devices use a harness that ensures the pack stays securely on the operator, and some include a large frame that the operator fits into.
Such designs are very insecure. Not only do they produce tremendous amounts of heat during operation, but they also create the potential for a deadly explosion due to engine failure or crash. This type of jet pack also requires a large amount of fuel, which must be carried or used by the operator.
More recent jet pack designs have used hydrogen peroxide instead of gasoline or other types of fuel. On its own, peroxide is fairly safe and not prone to explosions. When presented with certain substances, such as silver and other precious metals, peroxide undergoes a catalytic reaction that requires no heat and produces tremendous energy. This energy takes the form of superheated steam, which can be channeled into "boosters" that use the steam to propel the user off the ground.
There are even jet pack designs that use water, usually through a system tethered to a lake or ocean, drawing water into the device and then using it for propulsion. These systems are much more recreational in nature and lack military or other applications. More advanced designs have also used wings, allowing the jet or other method of propulsion to help get the user off the ground and provide momentum, and then use the wings to glide for sustained flight.