Jet Pack Dreams Take Flight

These dreams are about to make a hard landing.

Allow me to rephrase that - there is no chance that jetpacks will be a conceivable way of personal flight in the forseeable future. Imagine how inefficient space rockets are: gravity drag constantly works against you and at all times you have to create about 10N/kg of thrust just to keep from falling down. And this is thrust you have to provide by expelling mass from your engines. It will be a cold day in hell before it will be viable to use this technique to stay in the air for prolonged periods of time. The problems that make it difficult to climb into orbit are doubled for atmospheric flight through mass ejection. (This is also why purely chemical rockets will never turn into a cheap way of getting into orbit, another pet pieve of mine).

Until we should happen to master large-scale production and lightweight, mobile storage of anti-matter (right, that's only going to be in like 50 years or so anyway), wings and atmospheric displacement are the only viable ways to achieve atmospheric flight of any significant duration. And among those, only wings allow you to gain any significant speed. If anyone can point out a flaw in my physics I would be delighted, but as far as I can tell this is the reality we have to face. No amount of daydreaming is going to change Newton's laws.

On the other hand, strapping your body to a set of wings while wearing an aerodynamic suit and a lightweight chemical engine (like http://www.jet-man.com/prod/index.html) could probably be a viable and exciting way to get closer to the air. Unless my intuition is off you will not get very good fuel efficiency, but some people think that modern sailplanes or experimentals are not a sufficiently fun and cheap way to stay in the air and travel long distances fast.

And even that being said, politics is a much greater impediment to the development of aviation than physics has been for the last 100 years. Google "aviation lawsuit" for a small taste of what anyone not playing squarely by the book have in store for them.

Wow. It's 1965 all over again.

http://en.wikipedia.org/wiki/Bell_Rocket_Belt

Surprised that there was no remark on how loud it is to have a hydrogen peroxide burning rocket that close by. I was under the flight path of the Rocketman at last year's Tournament of Roses Parade. It was very cool but also the loudest noise I've ever been exposed to.

http://www.rocketman.org/events/RoseParade/

There are already untethered jetpacks out there! http://www.jetpackinternational.com/video.html There are more videos on YouTube somewhere. Try searching "jet pack rose parade" or "jet pack wired nextfest"

Looks like a lot of fun - a pity it only has a flight time of ~75 seconds at the moment (it does say they'll get it up to 35 minutes ... we'll see how that pans out).