Inside a warehouse in Christchurch, New Zealand, a man is fulfilling a fantasy many of us have had. He is levitating, a few metres above the ground. After hovering for a while, he flies around the space, his legs dangling below him, supported by a jetpack; a giant glossy white and black contraption strapped to his back. It’s lifted by powerful fans, and is making a deafening noise like a spacecraft from Star Wars. It’s a captivating demonstration.
Jetpacks like this one were first proposed in the 1920s, but it’s taken until today for practical models to take off. Advances in materials and computer control mean that the era of the jetpack could finally be upon us, almost 100 years after it was first proposed. Will you see one flying near you soon? If the engineers behind them are right, jetpack users could soon be fighting fires, responding to emergencies, and even saving your life.
A jetpack is usually considered to be a device that a person can strap onto his or her back, and which allows free, untethered flight. In the movies the devices are small, and their range is large, but in real life the opposite is true. The devices that have been demonstrated over the past few decades have been rocket packs, expelling a propellant at high speed to provide thrust and lift. A “rocket man” wowed a worldwide TV audience at the opening of the 1984 Olympic Games in Los Angeles, but his pack only contained enough fuel for about 30 seconds of flight, making it impractical for any less flashy application.
Another device that you may have seen, often over a lake, is the “water powered jetpack” where water is used as the propulsion fluid. Yet unlike free-roaming jetpacks, these machines require tethering a hose to a base unit, to feed water into the jet nozzles strapped to the flyer.
The limitations have not stopped engineers and entrepreneurs from dreaming of a device that would live up to the depictions in science-fiction. In the early 1980s, Glenn Martin formed the Martin Aircraft Company to fulfill his childhood jetpack fantasy. Decades later, the company now claims to have finally achieved their goal, via some smart propulsion innovations. In recent tests, the Martin Jetpack was showing off its capabilities by propelling a pilot around the inside of a warehouse in New Zealand (see video).
The jetpack is somewhat larger than the rocket-belt designs envisioned in the 1960s, yet its specifications are impressive. It is capable of flight up to 7,000ft (2100m) and speeds of 50mph (80kph). For lift, it uses two ducted fans – a type of propeller enclosed in a cylindrical shroud, like that of a jet. Propulsion comes from a specifically designed engine, similar to a motorcycle engine, but lighter and more compact. A tank of standard fuel can propel the jetpack for around 30 minutes, with a range of around 30km.
As well as early indoor tests that proved the concept worked, the company has been flying the jetpack outdoors under a range of conditions, using remote-control. “When we fly it remote control we fly it with about 105kg of weight on it, as though it had a man on it, in order to make sure we are testing it within the environment it’s going to be operating,” says Peter Coker, the CEO of Martin Aircraft Company, “and it’s flying very well.”
A recent high-altitude unmanned flight, to test performance up to 5,000ft (1,500m), was used to test the emergency get-out: a parachute. The Martin Jetpack will have a ballistic parachute system, which will automatically deploy in the event of an emergency. It can be automatically and explosively triggered, similar to the ejection seat from a fighter plane.