I used to work for this guy, for a company called Yodel (owned by Fulfilnet). I know it's not Hacker News worthy, but he's a really awful human being and I remember him coming into the building and firing people blindly just so he could make enough money to keep his jetpack hobby alive. He's British, so he started businesses in Australia and left them running remotely so he couldn't be brought down by them.
Sorry for talking about the person and not the technology, I just can't stand by when I watched this guy really screw people over for his own personal gain.
Sounds like two things: 1) Firing people blindly and 2) Doing #1 to fund an expensive hobby. Neither one really demonstrates responsibility that you'd want in a good leader, to say the least.
So to your question: Nothing. But embracing parent's experiential data: Everything.
I was a skeptic, but this looks unbelievably cool (even though they could have done a lot more cinematically).
However, jetpacks seem fundamentally limited to me because of the energy required. Perhaps a nuclear powered one would solve this? Or, the mythical massively higher density battery.
An alternative for personal flight is the powered parasail (aka parapont). There's a local guy who cruises around the bay shoreline at about 20-30feet, for a couple of hours. It's not capable of jetpack acrobatics, but more like seagulls soaring along a ridge.
Nuclear would definitely solve the endurance problem. Since there's no weight margin for shielding, a few minutes of fuel would suffice for a lifetime supply.
As someone who kitesurfs and is quite aware of how air moves around -- you wouldn't catch me flying one of those things in anything over 10mph, especially around tall buildings. Gusts, rotors, turbulence. Ugh. Scary enough when you're 20 foot above water. Deadly when you're over land.
The vertical take off landing makes for a much larger operating enevelope for a vehicle. The challenge is how to efficiently hover with out burning to much energy.
Larger rotors can out perform jets for efficinecy, ie rotors move a large volume of air at a slower velocity which is fundamentally more efficient then moving a small volume of air at a high velocity. You can also squeeze some more efficiency out of the system if you put a duct around the rotors, a duct can in itself produce ~40% of the total lift.
The Hiller flying platform which was built and test flown in the 1960's is a good model for something that could fly for 30-60 minutes with todays technology. You can search Youtube to find videos of its test flights...
A nuclear powered jetpack? Wait, sorry, what? Has there been some incredible development regarding either nuclear reactors or propulsion engines that I've missed out on?
If you don't mind heavy radiation, you could have a pu pile to rapidly heat air and blast it from a nozzle. This sort of thing was how project Pluto (bought to you by coors, of all people) worked. Nuclear powered cruise missile.
Not sure if you could make it quite small enough to stick on your back, and again, heavy radiation.
Pluto is an interesting one. So destructive that the plan was to have it just fly back and forth across the Soviet Union after it ran out of bombs, killing and destroying with the radiation from its unshielded reactor and the shock wave from flying past at low altitude at Mach three.
One of the (many) reasons it was killed was the question of how you would test such a beast. If it went haywire, you'd have a weapon on the loose that killed just by flying around, and with an enormous endurance. Oh, and which was basically impossible to shoot down.
It is listed on the ASX stock exchange, although hasn't released a product to market yet. However, I think they may be further down the line towards commercialisation.
The JB-9 looks more lightweight and fun, but the Martin has a parachute...
A parachute doesn't really make it safe. There is still a large "dead zone" where it would be too high for the pilot to survive a crash but too low for the parachute to work. Unlike a helicopter, the propulsion system doesn't have enough inertia to perform a power-off autorotation.
Some designs for larger powered lift vehicles have somewhat solved that problem by using multiple engines with cross-linked drive shafts. But that increases size, weight, and cost.
These jet pack devices may find a very limited niche market. But they don't have much of a real use case beyond looking cool on video. Most potential buyers will still prefer small helicopters, or drones.
I wonder if they could put in an electric hybrid system that could give a few seconds of propulsion to slow decent in the case of losing gas power. I have no idea though if that would even make sense because it seems like it would just increase the weight with no benefit.
Sure but it would require a complex, heavy, and expensive set of electric motors, transmissions, clutches, batteries, etc. At that point you might as well just use a helicopter.
The JetMan device is not a jetpack in the proper sense of the word. It's actually a full-fledged airplane (just mini size) with turboprops. It requires forward velocity to generate lift. Also, it can fly quite a bit longer than a jetpack.
A true jetpack generates lift reactively, and can hover at zero forward velocity.
Serious question, anyone know the ballpark figures of thrust-to-weight based on 1000 ft/min ascent rate for fully loaded and ground level?
I'm trying to calculate maximum theoretical fuel capacity, essentially 1:1 thrust-to-weight, given it burns kerosene - 6.82 lbs/gallon at STP.
10 gallons of kerosene = 68.2 lbs is much less than the weight variation of a standard adult human, which falls roughly in the range 100 lbs - 200 lbs, so doubling the fuel capacity should be easy.
I suppose engine upgrades would also be easy. They did mention the JB-10 was in the works...
Yea, 10 minutes of flight time seem incredibly high to me. That means you could significantly increase it with external fuel tanks (say, for a total of 20 gallons). 15 minutes would be a darn long jet pack ride. Limiting factor is actually just how much weight you could plausibly carry on your back.
it seems they are using pure jets and in this case high-by-pass would be a way to immediately improve the thrust and thus to decrease the fuel consumption.
Big city firefighters need these. They could fly up skyscrapers and rescue people or bring hoses way up there.
Mountain rescue teams could use them to extract people or get first aid to the sides of cliffs.
I remember watching Navy Seals jumping out of helicopters in San Diego harbor and then presumably swimming down to meet submarines. They could do this in reverse - climb out of a submarine and then flying up to the helicopter.
Except that you can't really carry additional weight (certainly not another person). Even a lightweight hose or line would mess up your flight if it was tethered. As for fires: burning buildings are masses of hot, moving air which wouldn't be navigable (the best you could do would be to land on an unaffected side of the building).
Even the Martin Jetpack (the only other nearly-commercial product in this market at the moment):
Private planes have existed for a long, long time and can carry a lot more explosives than this can.
Also, where are these "well-funded suicide bombers" I keep hearing about? The ones in the news all seem to be running on household chemicals, jacked-up cookware, and chutzpah.
Sorry for talking about the person and not the technology, I just can't stand by when I watched this guy really screw people over for his own personal gain.
Sources: http://www.ecommercereport.com.au/failed-businesses-yodel-bl... <-- This is the interesting one. After crashing his previous businesses he started up another and bought the assets and customers under a new name, then started fresh. New company is https://www.aiad.com.au/
https://en.wikipedia.org/wiki/Yodel_Australia
http://www.abc.net.au/news/2013-12-16/customers-left-in-the-...