Jet Packs, Finally On Sale

Bad_CRC1945 writes "The good news: Not one, but two companies are selling jet packs. The bad news: The tech has a long way to go. In the past, potential buyers have been stymied by two problems: Rocket belts aren't for sale, and even prototypes run on modern-day fuel (as opposed to whatever the Jetsons use) which means rocket belts can weigh upwards of 100 pounds, with only enough fuel to stay aloft for under a minute." That second problem's still with us, but the article hints that jet-fuel options (for the brave) could considerably extend users' time aloft.

Comments

Re:I've always wondered

[compro01]

Is the obsession with jetpacks just about being like a comic book superhero?

Pretty sure the answer is yes.

If one wants to fly without an airplane around them, an approach like the Martin Jetpack works much better. Far longer flight time and much more altitude. Cheaper fuel too.

Er,no - it's engine scalability.

[Kupfernigk]

Completely wrong. Piston engines are limited by the essential geometry of the cylinder/valve combination, plus the maximum piston speed which is geometry independent. Once a spark ignition cylinder exceeds about 500cc, its specific output starts to drop. Beyond 2 liters, diminishing returns set in with a vengeance. Mechanical complexity thus sets a limit to aircraft engine horsepower. (Marine engines can be huge because they don't have to worry about weight.) Turbocharging and supercharging eventually reach the point at which a lot of the thrust is being produced by the exhaust - at which point, replace the mechanical complexity of the piston engine with a relatively simple burner, and you have a jet engine which is simpler, lighter and more reliable.

Bottom line: above a few thousand KW, piston engines for aircraft are simply too complex, expensive and unreliable. The fuel is immaterial.