[HN Gopher] We have jetpacks and we do not care
       ___________________________________________________________________
        
       We have jetpacks and we do not care
        
       Author : zdw
       Score  : 210 points
       Date   : 2022-01-27 17:23 UTC (5 hours ago)
        
 (HTM) web link (www.theguardian.com)
 (TXT) w3m dump (www.theguardian.com)
        
       | spaetzleesser wrote:
       | We also have supersports cars that can go 200 miles an hour and
       | accelerate 0-60 in 2 seconds but not many people have one.
       | Current jetpacks are certainly interesting but almost useless
       | besides maybe a few very specialized things. As are supersports
       | cars. And both are prohibitively expensive for most people.
        
       | MomoXenosaga wrote:
       | We have flying cars and nobody cares (unless you're a bored
       | millionaire).
        
       | m1117 wrote:
       | It's like the NFT of aviation
        
       | msie wrote:
       | I hate that particular jetpack design where the arms are tied to
       | maneuvering thrusters. I like the other one by jetpack aviation.
       | https://jetpackaviation.com/
        
       | mrleinad wrote:
       | Sounds a lot like that quote from the 70s "there is no reason for
       | any individual to have a computer in their home."
       | 
       | That held true until prices dropped and computers were actually
       | useful to individuals and not room-sized machines.
        
       | arduinomancer wrote:
       | Isn't it a huge problem that a jetpack is not fail-safe?
       | 
       | With an airplane/paramotor you can still glide safely down if
       | your engine dies.
       | 
       | What would happen if the jetpack engine fails mid air?
        
         | wutbrodo wrote:
         | Wouldn't a parachute work? I know very little about
         | flying/aerodynamics, so I might be missing something obvious.
        
           | gs17 wrote:
           | It would work in some cases, but if you're too low it won't
           | necessarily have time to slow you down enough. The record for
           | the lowest BASE jump is about 100 ft, and that wasn't a
           | surprise equipment failure. Parachutes would help in a lot of
           | situations, but you would still easily die in a lot of other
           | situations.
        
           | jonathankoren wrote:
           | Ballistic parachutes exist for light aircraft. Seems like
           | they'd work here as well.
           | 
           | https://en.wikipedia.org/wiki/Ballistic_parachute
        
       | darau1 wrote:
       | If I could afford it I'd buy it and learn how to use it to
       | commute to work and back (safely, of course).
        
       | capableweb wrote:
       | > They can't hold enough fuel for more than eight minutes of
       | flight - and even that's the upper end. Kerosene is heavy, burns
       | quickly, and a human can only carry so much. A battery would be
       | far better, but they're much heavier - at least for now. Someday
       | someone might invent a battery light and energy-efficient enough
       | to do better than kerosene, but, for now, you can only use what
       | you can carry, and that's not much.
       | 
       | Seems there are good enough reasons for people to not really care
       | about jetpacks (yet). But it does seem like the military/law
       | enforcement could have some use for it, mainly for boarding
       | moving vehicles and/or scaling walls/barriers.
        
       | mikestew wrote:
       | If you think leaf blowers are loud and blow shit everywhere, wait
       | until folks have a leaf blower powerful enough to lift a human
       | being with its output.
       | 
       | Point being, we never wanted them in the first place, we just
       | didn't know it.
        
       | sevenf0ur wrote:
       | My brother has flown one of these on a tether. They are
       | deafeningly loud and put out tons of heat so you need special
       | clothing and it needs to be cool downed after use. Have to fly
       | low to the ground or over water where you are better off with
       | other means of transportation. Not to mention this thing runs out
       | of kerosene in 10 minutes. Not practical for consumers in the
       | slightest.
        
       | pqdbr wrote:
       | Nobody cares because we have something better. It's called
       | paramotoring.
       | 
       | Saying it changed my life wouldn't be an overstatement. The
       | ability to store it inside my sedan, travel anywhere, take off
       | with my own feet, fly anywhere for around 4 hours, and land
       | basically anywhere... is just magical.
        
         | JKCalhoun wrote:
         | You've got my attention.
         | 
         | Been watching these kids with paramotors on YouTube blaze
         | across fields, drop in on a rural McDonalds.... It looks like
         | fun ... and safe enough?
        
           | pqdbr wrote:
           | It's the best thing you can do with your clothes on, lol. And
           | extremely safe. I've been flying for 4+ years and I never
           | even twisted an ankle.
           | 
           | Actually, if you like adrenalin, I'd suggest looking
           | elsewhere. I did skydiving for many years before discovering
           | paramotoring, and they are completely unrelated activities.
           | 
           | Yes, you can do high speed flying and "slalom" with your
           | paramotor, but 98% of us don't. It's a contemplation sport.
           | Like going on a bike ride or jetski ride with your friends,
           | but in 3 dimensions. It's all about the views, soaking up the
           | scenery, and having a good time in the sunset or in the
           | sunrise. If you live near the beach, you can fly all day; if
           | you live in the countryside, you'll probably fly early in the
           | mornings or in the sunset, due to the lower thermal activity
           | (it gets bumpy otherwise).
           | 
           | If your engine fails ... you have a huge "parachute" that
           | sails 6 meters forward for ever meter down. Actually, every
           | single landing we do, we are either with our engine
           | completely shutdown or idling. I've had 3 malfuctions in
           | these 4 years; as long as you're flying watching your "safety
           | cone", you'll slowly glide to a pleasant landing.
           | 
           | If your main glider fails (they don't, but our main enemies
           | are kites; their lines can cut through our lines like
           | butter), you still have a reserve chute that you can throw as
           | a last resort.
           | 
           | If you fly over water, equip yourself with flotation devices.
           | There are many specific to paramotors that inflate
           | automatically.
           | 
           | What defines the sport is the wing you choose. You'll get
           | trained by an instructor, and he'll guide you to the best
           | wing according to your weight and desires in the sport.
           | 
           | Basically:
           | 
           | - Get professional training; - Get a good equipment and a
           | wing suited to your weight; - Don't fly over water without
           | flotation; - Always watch your "safety cone" in the event of
           | an engine out; - Don't fly spirals near the ground (don't be
           | a showoff); - Beware of your weather forecast and land if
           | winds go over your comfort speed;
           | 
           | You literally become a drone (mine is getting dust and never
           | flies anymore). It's incredible. If you have the chance, get
           | yourself trained, you'll add a whole other dimension to your
           | life.
        
             | [deleted]
        
           | asciimov wrote:
           | Nothing is safe, you just have to acknowledge the risk
           | involved and accept it.
           | 
           | Risk is everywhere, if you accept the risk involved you may
           | find yourself having a good time.
        
             | 8bitsrule wrote:
             | Back in 1884 at Coney Island people paid a nickel and lined
             | up for a 600-foot ride (at _6 miles per hour_!) on the
             | first  'roller coaster'. (Some of them probably fainted!)
        
           | Toutouxc wrote:
           | > and safe enough?
           | 
           | They're like motorcycles. Do everything right and it's almost
           | safe (someone else can hit you on the road and there are rare
           | meteorological phenomena able to bring a paramotor down, e.g.
           | a microburst), but even small errors can result in severe
           | injury or death.
        
         | jodrellblank wrote:
         | https://www.youtube.com/watch?v=L1Z8YT6w7Rc - guy flies to
         | 17,500 feet on his paramotor.
         | 
         | I didn't know they were a thing before watching this. Amazing.
        
           | brailsafe wrote:
           | Dude takes off from a rather unsettling neighborhood, damn.
        
           | lsh123 wrote:
           | And also collide with planes:
           | 
           | https://www.star-
           | telegram.com/news/state/texas/article256764...
        
             | Toutouxc wrote:
             | Well, paramotors are actually a bit less prone to mid-air
             | collisions (aside from showing off, wing tip bumping etc.),
             | because they're usually brightly colored, the pilots have
             | perfect visibility, they fly slow and usually pretty low
             | (lower than most airplanes).
        
               | imoverclocked wrote:
               | I think it's more due to the big sky theory.
               | 
               | When flying even a modest GA aircraft VFR, there isn't
               | much time to react if you've been looking down at
               | foreflight/instruments for 30 seconds while heading
               | straight towards a paramotor which has no ADS-B out. This
               | says even more for IFR craft that move much faster.
        
         | austinl wrote:
         | I've just been getting into paragliding (i.e. without the
         | motor), and have been absolutely loving it. It blew my mind to
         | learn that by riding thermals, paragliders can essentially stay
         | in the air indefinitely. My longest flight so far has only been
         | about 15 minutes, but people are regularly in the air for
         | hours.
         | 
         | For some more inspiration, check out "speed flying" --
         | essentially, paragliding with skies:
         | https://youtu.be/UwWLnaME0CI
        
           | mrtksn wrote:
           | I used to do paragliding back in college, definitely prefer
           | it to paramotoring because no engine noise and much more
           | agile wings.
           | 
           | However I wouldn't relate it with "speed flying" because
           | speed flying is a truly an extreme sport with extremely high
           | mortality but paragliding is a chill flying unless you choose
           | to make it extreme.
           | 
           | Paragliding is so safe these days, the wings are very stable
           | and spontaneously return to airworthy shape if disrupted.
           | Flying is very chill, to do something at high speed you
           | usually need to build up energy by spiralling or swinging the
           | wing.
           | 
           | Speed flying on the other hand uses much smaller wings and
           | that makes them very dynamic. They fly at much higher speeds
           | and they have high kinetic energy all the time which results
           | in very large movements even at small inputs from the pilot.
        
           | ngngngng wrote:
           | Utah has a couple spots that are popular for paragliding.
           | I'll never forget the time we visited one of the popular
           | launch spots and saw a man get so high within minutes that we
           | couldn't see him anymore.
        
         | wnolens wrote:
         | It's such beautifully "simple" system that makes so much sense.
         | I love it.
         | 
         | lol @ bajillion dollar R&D jetpack with ai controlled thrust
         | vectoring
        
         | jedberg wrote:
         | TIL about paramotoring. I'd seen the rigs before but didn't
         | know the name.
         | 
         | I googled it and the first thing that came up was a YouTube
         | video about the 5 most dangerous things about paramotoring. :)
        
           | petre wrote:
           | I wouldn't try paramotoring without doing at least a 6 month
           | paragliding course first. Which in fact I did when I was 21.
           | After I saw a colleague make a judgement error, fall from
           | 30ft, hit the ground and jump like a soft ball I became
           | stressed during flight. He had flown a DHV31 paraglider
           | though and was not experienced enough to fly that wing.
           | Current DHV1 wings are much more safer and very performant
           | compared to 2000 era wings that we've flown. Shortly after
           | the fall incident a guy I became acquainted with died during
           | a competition. I just gave up because it stopped being fun.
           | My instructor had an accident with a powered hang glider few
           | years afterwards. He still has a bad limp to this day. He has
           | always been very safety conscious and had at least 25 years
           | of prior aviation experience, parachuting and paragliding,
           | when his accident occured.
           | 
           | Anyway, I find paramotors quite offensive because they make
           | an awful lot of noise and smoke and the pilot's position is
           | quite unnatural compared to normal paragliding because the
           | motor pushes him or her forward. Maybe when we'll have
           | electric paramotors under 10 kilos things will change for the
           | better.
           | 
           | 1. https://www.dhv.de/en/testing/dhv-classification-of-
           | paraglid...
        
             | psyc wrote:
             | The transitive PTSD from your fellow pilots dying is real.
             | I quit after 800+ flights (including motored, and yes it is
             | incredible) after the 5th death of someone I'd either been
             | close to or at least on adventures with. Not to mention all
             | the broken vertebrae which is a lot more common than death.
             | In the span of a few years I saw three ridiculously
             | experienced instructors (one had like 8,000 flights) smash
             | into the ground, then spend 2 months in the hospital and a
             | year recovering.
             | 
             | The fact that we know what mistakes they made is a red
             | herring. You'd have to be a fool to think you're going to
             | be the first paragliding pilot in history to never make a
             | potentially fatal mistake. One of them, a friend and a very
             | good pilot, simply pulled his brake half an inch too far.
             | It was a perfectly calm evening.
             | 
             | There were two warring factions at my local mountain. One
             | organized around the idea that paragliding can be made
             | safe. My camp maintained that 'safe' and 'paragliding'
             | should never be in the same sentence without an 'isn't'
             | between them. Hikers always opened conversation with "Is it
             | safe?" The other camp would say "Oh yes, quite, and would
             | you like a ride for $200?" Our camp would try not to laugh.
             | I'd usually reply with, "Does it look safe?" We said it was
             | all about risks and percentages, with the understanding
             | that the risk of dying or being crippled with a slow glider
             | in perfect conditions is always > 0.
             | 
             | I'm not saying it isn't worth it. It's totally worth it,
             | though it's easier for me to say since I got out unharmed.
             | Rather, I developed a discomfort that prevented me from
             | enjoying it. Not fear - but a kind of disillusionment.
             | Because even though my instructor said "It's not safe."
             | over and over, and even though I repeated it to others,
             | secretly I believed it was and it took 8 years for observed
             | events to wear that belief down. A big part of me hopes I
             | return, maybe after my parents are gone or I'm their age or
             | something. There is really nothing like it in the world and
             | I doubt anything I ever do will ever energize my soul the
             | way free flying did.
        
               | petre wrote:
               | Flying is nice but shaky and unpredictable weather still
               | makes me uneasy. If I'll ever try it again it will be in
               | a sailplane or a light airplane.
        
           | mtinkerhess wrote:
           | I found the same video it looks like all those dangers are
           | preventable? Don't do acrobatics at low altitude, don't fly
           | over water, don't start the engine on the ground, don't buzz
           | trees or other obstacles, don't get close to other paramotors
           | in flight.
        
         | savrajsingh wrote:
         | How/where did you get training?
        
           | yurishimo wrote:
           | You can find a club in most large cities. In the US at least,
           | the biggest problem is getting far enough away from the city
           | so you don't become a hazard to commercial plane traffic.
           | 
           | I live in the DFW metroplex, and you have to drive almost 100
           | miles out of the city to take-off and then you're pretty
           | limited on where you can fly due to the abundance of small
           | airports nearby.
           | 
           | There are maps available that show what kind of airspace is
           | around you. I forget the specifics as it's a been a few years
           | since I looked into it, but there are different designations
           | for what/who is allowed to fly where and paramotors are very
           | low on the totem pole in terms of priority and access
           | allotments.
        
           | pqdbr wrote:
           | Just google for paramotor training, there are many schools in
           | the US. I suggest get training near the place you plan to do
           | most of your flying, because flying at the beach with
           | constant, laminar, mid-strong winds is very different than
           | flying at the countryside with bumpy and low-mid winds.
           | 
           | If in doubt, learn to fly near the beach. The views are
           | amazing :)
        
         | jerf wrote:
         | It's a pet peeve of mine that people think that sci-fi authors
         | writing decades before the tech exists somehow got the design
         | right, just because Hollywood made some pretty moving pictures
         | that fired up your imagination.
         | 
         | It's hard enough to design things in the real world when you've
         | got the tech in hand. There's no way to think that people got
         | it right decades earlier with even larger disadvantages.
         | 
         | The reality is we don't have jetpacks because jetpacks
         | _suuuuuuuuuck_. Paramotoring turns out to make a lot more
         | sense. It may not be the picture in your head, but it can be
         | _real_.
         | 
         | Also, we don't have flying cars because flying cars
         | _suuuuuuuuuck_. We don 't have heavy-duty voice interfaced
         | computers because they _suuuuuuuuuck_. We even have the tech
         | now for those, and they _suuuuuuuuuck_ as the only interface.
         | (They can work if you 're dedicated and have no alternatives,
         | as people program with pure voice interfaces, but they only use
         | them because they're the best alternative they have.) Computer
         | interfaces don't look like LCARS Star Trek interfaces because
         | those interfaces _suuuuuuuuuck_. And so on.
        
           | benjiweber wrote:
           | Android is starting to look quite LCARS
           | https://twitter.com/benjiweber/status/1457039757112922115
        
           | 6gvONxR4sf7o wrote:
           | The other side is my own pet peeve: thinking that sci-fi
           | authors were visionaries for putting something out there
           | before anyone else makes it real. One reason we don't have
           | flying cars could be battery tech, taking your example.
           | There's a ton of cool shit happening in aviation as batteries
           | improve.
        
             | Ekaros wrote:
             | Flying without lift from wings or like as people think of
             | sci-fi flying cars isn't practical, unless we break the
             | physics as we understand today. I honestly can't think of
             | anything more wasteful than hovering flying car...
        
           | the8472 wrote:
           | Jetpacks only suck due to the lack of a compact power source,
           | one of the things that's commonly handwaved in scifi. If we
           | had a magical power source they'd provide a more dynamic
           | flying experience than gliding.
        
             | jerf wrote:
             | They have a poor backup if a component fails, they're
             | either going to be blasting something hot or something very
             | fast out some set of ports which raises a lot of practical
             | issues, they're always going to be very loud, greasing them
             | up with enough AI to be safe for a normal person is going
             | to be a massive problem, they'll always be difficult to
             | control because such a small, fast thing is going to be
             | super responsive and thus very twitchy and difficult to fly
             | (or, to put it another way, "more dynamic flying
             | experience" is a _con_ , not a _pro_ ), and the list goes
             | on.
             | 
             | Basically, a jet pack what you get if you take a minimal
             | safe flying vehicle based on jet propulsion, then you strip
             | away a huge number of components. The result is
             | intrinsically unsafe.
             | 
             | Paramotoring isn't the safest thing either, but at least
             | it's humanly feasible.
        
         | didip wrote:
         | wow! I have seen this in real life but had no idea what's the
         | name.
         | 
         | It definitely seems simpler and safer than jetpack.
        
       | danboarder wrote:
       | With sufficient flight controller integration and sensors &
       | software the jetpack form factor could be as easy to fly as a
       | self balancing Segway is to ride around. Current semi- autonomous
       | drone software like what we see in the Skydio 2 would be an
       | interesting direction for this tech, one would end up basically
       | riding a drone around at low altitude. I am optimistic for near-
       | future electric implementations and practical progression in this
       | type of e-mobility development.
        
       | [deleted]
        
       | JasonFruit wrote:
       | Ultralights and hang gliders are nowhere near as dead as this
       | article seems determined to assert, using anecdotes without data.
       | (How do I know? Also anecdotes, unfortunately, as their
       | deregulated nature makes data hard to come by.) But this article
       | paints the bleakest picture of personal flight possible, and I'm
       | not convinced they have the facts straight -- except about jet
       | packs, which are about as practical as a human cannonball.
        
         | jeffreyrogers wrote:
         | In Salt Lake City lots of people flew paragliders. But they
         | also have a great place to fly from that's close by.
        
       | duxup wrote:
       | When the jetpack can fly for me for the most part, I'm down with
       | it.
       | 
       | Kinda like small drones. I own one, because it is easy to use.
        
       | zdw wrote:
       | It's basic physics - anything that can rapidly accumulates
       | potential energy in terms of gravity without a safe way to slowly
       | dissipate that energy as it is turned to kinetic can be
       | dangerous.
       | 
       | See also how people get killed by falling tree limbs and
       | coconuts.
        
         | jonathankoren wrote:
         | Kinetic energy. Potential energy is perfectly safe. :)
        
         | jeffreyrogers wrote:
         | Skydivers solved that problem with parachutes.
        
       | AcerbicZero wrote:
       | We have shitty jet packs and we do not care.
        
       | csours wrote:
       | No mention of TikTok yet. How long until a motivated teenager
       | gets ahold of one of these and starts a trend?
        
       | mschuster91 wrote:
       | > With smaller aircraft, the trends are similar. Hang-gliding has
       | all but disappeared. Ultralight aircraft makers are barely
       | staying afloat. (One manufacturer, Air Creation, sold only one
       | vehicle in the US last year.) With every successive year, we have
       | more passengers and fewer pilots.
       | 
       | Yeah, no surprise given that
       | 
       | - planes are expensive to buy - even small ones are in the upper
       | five figures range
       | 
       | - planes are expensive to operate: ~150-200$ in fuel per hour
       | IIRC, plus insurance, maintenance costs, hangar and
       | airport/landing strip fees
       | 
       | - getting a license is expensive: even a basic private pilot
       | license will set you back ~7500-10000EUR, and on top of that come
       | type ratings and other extras (instrument flight, radio, ...)
       | 
       | - _maintaining_ that license is expensive: you need to keep up
       | flight hours either in real flight or in (only a bit less
       | expensive) simulators, and there are severe restrictions on
       | passengers if you 're not on a commercial license
        
         | ramesh31 wrote:
         | Not to mention dangerous. Commercial aviation is exceedingly
         | safe -- safer than riding a train by passenger-incidents/mile.
         | But general aviation is about on par with motorcycle riding.
         | There was a big push in 60s/70s/80s to market general aviation
         | to the public as being the same as driving a car. But the
         | reality is that most people cannot and will not ever be able to
         | safely operate an aircraft without full automation.
        
       | Avlin67 wrote:
       | I had an opportunity to see it in action... well the guy took at
       | least 20min to set up and event 100meters away i was hooked by
       | the strong smell of unburnt kerozene.... in france you can barely
       | put a sticker on your car legaly - forget any idea of even pseudo
       | tuning - yet we are excited about gogo gadgeto burning flying
       | man. it is so startup nation...
        
       | todd8 wrote:
       | The real problem is the potential energy one has at even a low
       | altitude is enough to kill you, even without a jet powered
       | velocity towards the ground.
       | 
       | A fall from just 100ft (~ 30m) is like being hit by a train
       | traveling at 54mph (87kph). Any malfunction at this height would
       | in a couple of seconds likely result in death. Without some sort
       | of anti-gravity belt I don't see jetpacks as being useful.
        
       | trgn wrote:
       | I sincerely hope we will never care. That in the US, our
       | mentality gets past this infantile fetish for powertools and
       | convenience. It's a vestige of high modernism, an adolescent
       | ideology that life must be mediated by technology. Scraping food
       | of a plate in the trash beget flushing food down the drain
       | through a garbage disposer. Athletics beget motorsports. It
       | crystalized in the 50s, oddly a decade where adults began to
       | watch cartoons like the Jetsons, like children.
       | 
       | Jetpacks are the perfect example. It conflates the ability to fly
       | anywhere anytime with freedom. It is a toddler fantasy. Similar
       | to how cars for personal transport have not increased freedom,
       | but instead delivered obesity, fossil fuel dependence, and a
       | polluted, and threatening public realm.
       | 
       | The aspirational city life of the future will be one of
       | sophistication and maturity. It will be the an improved version
       | of the city life of the pre-industrial age. Where the only sound
       | is the chatter of passerbys and their footsteps. At night, it is
       | quiet. Everything degenerate (human waste, cars, metros, ...)
       | will be pushed underground. The sky will be as pristine as in the
       | wilderness.
       | 
       | In other words, it will be an environment where flying a jetpack
       | is sociopathic.
       | 
       | This is not a personal fantasy. This kind of urban environment is
       | where people with means are moving to _today_. It is the main
       | program of every European city. The US is slow to shake these
       | destructive 50s ideals of transportation. But it is happening.
       | Hopeful to see it in my lifetime still.
        
         | analog31 wrote:
         | In my hometown the city code said the garbage disposer was a
         | measure against rats.
        
       | mrfusion wrote:
       | It's not that no one cares. We just want one that's under 20K,
       | has more than 45 minutes flight time, isn't loud or bulky, and is
       | extremely safe.
        
         | pqdbr wrote:
         | Not a Jetpack per se, but take a look at a paramotor.
        
         | [deleted]
        
         | titzer wrote:
         | I think society is exhausted from all the excitement. It feels
         | like people would be excited by jetpacks for about 5 minutes
         | and then return to their dopamine loops--primarily phones.
        
         | paxys wrote:
         | I can assure you if all of those happened it still wouldn't get
         | any significant adoption. What even is the use case beyond
         | joyrides at fairs?
        
           | mrfusion wrote:
           | I for one would commute with it! Fly by the lights and
           | traffic jams.
        
         | petercooper wrote:
         | And legal. A lot of places can't even get their heads around a
         | scooter that can go 15mph.. so I'm not sure jetpacks are going
         | to fly.
        
           | saftamihai wrote:
           | "not sure jetpacks are going to fly." I lol'd
        
           | addaon wrote:
           | The US has a truly incredible rule -- 14 CFR Part 103,
           | usually shortened to Part 103 -- that basically deregulates
           | ultralight aircraft, other than restricting their airspace
           | usage. The logic behind this rule is that it defines
           | ultralights tightly enough (low weight, low kinetic energy,
           | restricted use over populated areas) that you're probably
           | only going to kill yourself if something goes wrong; and what
           | can be more American than allowing that?
           | 
           | The main defining features of a Part 103 ultralight are empty
           | weight (< 254 lbs, including battery but not including up to
           | 5 gallons of fuel, and with additional credits for parachutes
           | and floats), minimum flight speed (stall speed for a fixed
           | wing aircraft) of <= 24 kts or calculated equivalent (see AC
           | 103-7), and maximum horizontal flight speed of 55 kts (with
           | electronic or other artificial restriction of speed being
           | acceptable).
           | 
           | Many of the "jetpacks" and other ultralight VTOL ideas being
           | explored right now easily fit within Part 103, so in the US
           | these certainly can fly, at least for very limited
           | recreational usage.
        
             | throwaway0a5e wrote:
             | The hand wringers and spineless politicians looking to
             | score a few cheap brownie points for advancing "safety"
             | will go after jet-packs if they ever become seriously
             | viable. Look at all the hand wringing over the unwashed
             | masses getting their hands on cheap and fast ebikes. Right
             | now nobody cares because they're just rare toys for rich
             | people.
        
               | brimble wrote:
               | No-one's freaking out about those parachutes with a
               | lawnmower engine & seat attached, and those have been
               | around for many years and can be seen flying all over (at
               | least) the rural Midwest.
               | 
               | Now, flying them over other people's property or over a
               | city is, and should be, another story.
        
               | Dylan16807 wrote:
               | > Now, flying them over other people's property or over a
               | city is, and should be, another story.
               | 
               | It's not "one of the most dreamed of forms of flight -
               | jetpacks" if you can't fly around town.
        
               | ashtonkem wrote:
               | Right, and that's probably never going to happen because
               | of noise issues alone.
        
               | WJW wrote:
               | Jetpacks are a little bit like the Elon Musk tunnel
               | digging startup: it is something you dream about when
               | stuck in traffic during your commute.
        
               | Dylan16807 wrote:
               | Sort of, but a tunnel network of that type is never going
               | to be able to handle many users, no matter how good the
               | design gets, while improved and safe jetpacks probably
               | could replace most of the cars on the road.
        
               | WJW wrote:
               | I doubt it, for basically the same reason that electric
               | bicycles are not going to replace most of the cars. They
               | might be great, but are not very nice for long commutes
               | in poor weather (while wearing fancy suits or
               | dresses/skirts).
               | 
               | For jetpacks there is an additional huge problem with
               | safety flying over inhabited areas. Unless the jetpacks
               | are _meticulously_ maintained and inspected, we would see
               | people falling out of the sky on the daily. Taking the
               | maintenance state of most cars as an example, it seems
               | safe to state that it would be infeasible to expect the
               | general population to keep their jetpacks in an
               | acceptable state.
        
               | Dylan16807 wrote:
               | Electric bikes are also significantly slower than cars
               | and expose you to a lot of ground-based hazards, even on
               | the days with the best weather.
        
               | Tostino wrote:
               | It's honestly gone better than I expected as someone who
               | built their first ebike back in 2006.
        
             | kashkhan wrote:
             | SS 103.15 Operations over congested areas.
             | 
             | No person may operate an ultralight vehicle over any
             | congested area of a city, town, or settlement, or over any
             | open air assembly of persons.
        
             | tshaddox wrote:
             | > you're probably only going to kill yourself if something
             | goes wrong; and what can be more American than allowing
             | that?
             | 
             | I don't think the reason for this deregulation is that the
             | FAA doesn't care if you only kill yourself, but rather that
             | the number of people interested in doing this is and was
             | _in practice_ incredibly small. Yes, anyone _can_ go buy a
             | paramotor for $10,000 and probably figure out how to
             | operate it just well enough to be able to kill themselves,
             | but _in practice_ this is extremely rare.
             | 
             | You can be sure that if it somehow became wildly popular
             | for people to buy these things and it was causing lots of
             | problems, the regulations would change. The exact thing
             | happened with the massive popularity of "drones," which
             | were similarly deregulated because the usage of RC aircraft
             | had also been limited to a small number of RC clubs around
             | the country.
        
             | the8472 wrote:
             | > including up to 5 gallons of fuel
             | 
             | That's enough to reach critical mass of many fissile
             | elements. I wonder if it would be possible to build a
             | miniature nuclear rocket with enough thrust to lift a
             | human. The weight budget probably isn't enough to include
             | enough shielding.
        
               | jeffreyrogers wrote:
               | You would need to get regulatory approval to operate the
               | reactor.
        
         | outworlder wrote:
         | > It's not that no one cares. We just want one that's under
         | 20K, has more than 45 minutes flight time, isn't loud or bulky,
         | and is extremely safe.
         | 
         | That's a paramotor.
         | 
         | Still, not enough people care.
        
         | SideburnsOfDoom wrote:
         | > under 20K, has more than 45 minutes flight time, isn't loud
         | or bulky, and is extremely safe.
         | 
         | These are of course, impossibly contradictory requirements for
         | a jet-engine device.
        
       | zxcvbn4038 wrote:
       | We have ray guns too but the batteries need a fork lift which
       | takes away all the fun!
       | 
       | I guess in the mean time all the would-be Buck Rogers can save
       | the world by running over the aliens with their fork lift and
       | dropping heavy batteries on them. Board with a nail not included.
        
       | Animats wrote:
       | As usual, flying is easy, but landing is hard. Someone commented
       | on a previous generation of jetpacks that "knees are terrible
       | landing gear".
       | 
       | What are they using for a turbojet engine? One of the great
       | frustrations of light aircraft is that nobody has been able to
       | make a cheap and reliable jet aircraft engine. It's possible to
       | make one small and light enough, but they don't seem to get any
       | cheaper below 6-passenger bizjet size. NASA put some effort into
       | this in the 1990s, and Williams tried, but all that happened was
       | that bizjets got a bit better.
        
         | chipsa wrote:
         | RC aircraft jet engines like:
         | https://en.wikipedia.org/wiki/JetCat_P400
        
           | Animats wrote:
           | _" It is with unimaginable sadness that we announce the
           | passing of Jetman Pilot, Vincent (Vince) Reffet, who died on
           | the morning of 17 November during training in Dubai."_
           | 
           | Mfgr: (via Google Translate) _" The CAT JetCat model jet
           | turbines are designed exclusively for model flying and are
           | not suitable for any other purpose. Definitely not for people
           | or use goods or by any other means, except exclusively for
           | model aircraft, because any other uses lead to personal
           | injury or death can."_
           | 
           | There are low cost (well, US $10,000) jet engines, but they
           | are not human-rated.
        
       | taubek wrote:
       | I remember jetpack from opening of Olympic games in L. A. in
       | 1984.
       | 
       | I was surprised to learn that jetpack used in James Bond movie
       | Thuderball from 1965 was a real jetpack.
        
       | dukeofdoom wrote:
       | Flying skateboards is what we are waiting for
        
       | TimTheTinker wrote:
       | > For decades, humans have said they want jetpacks, and for
       | thousands of years we have said we want to fly, but do we really?
       | Look up. The sky is empty.
       | 
       | I have wanted to become a small plane or ultralight pilot since I
       | was in high school (I'm nearly 40 now)... it's just that with a
       | single income and kids, life is expensive and busy.
       | 
       | I was astonished recently while watching _The Spirit of St Louis_
       | (the 1957 Jimmy Stewart movie) - how as a young man Charles
       | Lindbergh drove into Souther Field, bought an army surplus Jenny
       | biplane for $500 cash (about $8000 in today 's dollars), and took
       | off immediately without any bureaucracy. Oh for that kind of
       | freedom!
       | 
       | Maybe I'll do paramotor training with my kids when they're in
       | their late teens - but for now, I can only stare up at the sky
       | and dream (and occasionally watch YouTube videos of others living
       | that dream).
        
         | ashtonkem wrote:
         | Flying has gotten more expensive, but not that much more
         | expensive if you're really motivated. Kit airplanes can be
         | fairly cheap, $30k for a kitfox, and often can be maintained by
         | the owner because they're amateur built.
         | 
         | The issue is the same as Lindbergh's day though. Amateur built
         | airplanes are not safe.
        
         | bener wrote:
         | You'll get there! Initial "trial" flying lessons can be
         | relatively cheap, and in my case the tutor was letting me take
         | off and land on my second lesson (with dual controls of course,
         | I wasn't very good)
        
       | dieselerator wrote:
       | I find the article interesting in that it provides us a first
       | person view of operating the machine. We get a perspective about
       | the current state of jetpack development. We become aware a timer
       | (ie, fuel gauge) is the primary flight instrument. I am happy to
       | read about this rather than needing to have the experience
       | myself.
        
       | hooby wrote:
       | People have always dreamed of flying... in highly varying
       | intensity.
       | 
       | At the one extreme we got people afraid of flying and never
       | wanting to leave the ground at all - and at the other extreme we
       | have people absolutely obsessed with flying.
       | 
       | But I think we have a reached a point where everyone along that
       | spectrum can get their fill of flying more or less easily.
       | 
       | For a lot of people, taking a commercial flight and getting a
       | window seat might already be enough to scratch that flying itch.
       | 
       | Those who want a bit more than that can easily book a flight in a
       | small propeller plane, or a helicopter or a hot air balloon.
       | 
       | People who want even more can go paragliding, or hang gliding, or
       | sky diving.
       | 
       | And those who want the most extreme flying package they can
       | possibly get - well those people no longer dream of jetpacks -
       | those people do fly wing-suits now.
       | 
       | There's no niche left for the jetpack to fill - every type of
       | flying desire is already being served. And instead of going with
       | a jetpack, you could also choose something that's just as
       | exciting but a lot safer and cheaper - or something that's just
       | as dangerous but a lot more exciting and still cheaper.
       | 
       | The jetpack was more fascinating while it was the most exciting
       | option imaginable, and more longed for, during a time when any
       | kind of flying was just out of reach for most people.
        
       | friendlydog wrote:
       | Hoverbikes seem more in reach for price and safety.
        
       | 3pt14159 wrote:
       | Yes.
       | 
       | That's because they cost more than $300k and can only fly for ten
       | or so minutes. If they costed 1/10th that and could fly at the
       | very least 4x that then people would be losing their minds over
       | these things. They are fast enough. Cool looking enough. Etc.
       | Just bring down the price and up the range.
        
         | jakear wrote:
         | A bit like a hang glider? Article claims interest in them has
         | declined as well.
        
           | HALtheWise wrote:
           | A major reason for the decline in interest in hang gliding is
           | dramatic technical improvements in paragliders, which are
           | quite a bit more portable and cheaper for an increasingly
           | small performance hit. Combined interest in paragliders and
           | hang gliders is at an all time high.
        
       | mettamage wrote:
       | For the people suggesting paramotors as the actual jetpacks of
       | our time (in terms of promise), there never has been a paramotor
       | topic at the frontpage!
       | 
       | I found this submission quite fun [1, 2].
       | 
       | It was submitted to HN twice and only got 4 upvotes (I used the
       | HN searchbar and typed: paramotor).
       | 
       | [1] https://www.justine-haupt.com/blimpdrive/index.html
       | 
       | [2] https://youtu.be/5pPJ-Z4vVyI
        
       | jokoon wrote:
       | Seems like using 4 rotors or jet engines around the pilot might
       | be a better solution.
        
         | jonathankoren wrote:
         | I keep thinking about about the Hiller VZ-1. Like standing on a
         | blender.
         | 
         | https://en.wikipedia.org/wiki/Hiller_VZ-1_Pawnee
         | 
         | Which coincidentally, kind of makes an appearance in the
         | opening of Jonny Quest https://youtu.be/7gNBFmlNUfM?t=38
        
       | ultra_nick wrote:
       | I had a project idea for a hoverpack instead of a jetpack. It
       | would only cancel gravity in short busts to enable people to
       | super jump over things. The reduced power needs lowered the total
       | price to around $5,000. No time to build it though.
        
       | seafoam wrote:
       | It would be good to understand the failure characteristics.
       | 
       | Is the risk comparable to a wing suit, or a helicopter, or a
       | single-engine plane ?
        
         | mh- wrote:
         | I think the failure characteristics are pretty easy to
         | understand.
         | 
         | They'd fall into two categories:
         | 
         | - Sudden loss of power
         | 
         | - Mechanical failure that results in unscheduled disassembly
         | 
         | As these crafts have no aerodynamic surfaces like the 3 other
         | things you compared them to, the first category would result in
         | the rider falling from whatever height. (Minimum altitudes to
         | successfully deploy even a BASE parachute are higher than one
         | might think.)
         | 
         | And well, the second category should be self explanatory. An
         | explosive failure of the stuff strapped to your back would just
         | create extra excitement or death before proceeding reverting to
         | the first failure mode.
        
         | lordnacho wrote:
         | There might be a missing scenario in your list: bag of
         | potatoes.
        
       | jpswade wrote:
       | This comes up every so often and I think the reality is, yes
       | people would like jet packs but they would prefer to be safe.
       | 
       | Reminds me of this sketch.
       | 
       | https://youtu.be/vDIojhOkV4w
        
         | jodrellblank wrote:
         | I love the quiet commentary of this Mitchell and Webb "Jump off
         | a cliff" sketch https://www.youtube.com/watch?v=DTcBWo4Aj0g
         | 
         | Compared to all the killer theme park attractions and extreme
         | sports. "It's all fine though?" "Yeah it's all fine". That's
         | enough.
        
         | BatFastard wrote:
         | that was perfect!
        
       | Toutouxc wrote:
       | Even helicopters burn fuel like crazy when hovering out of ground
       | effect, and the only reason we use them are their huge main
       | rotors that get some of that efficiency back when actually moving
       | at speed, and also because they're the only thing available.
       | 
       | Anything fighting gravity with pure thrust is basically DOA at
       | this point, and double that for inherently inefficient propulsion
       | methods like jets. Ducted fans, maybe, but most likely not. And
       | that's still allowing for fossil fuels and huge fuel consumption.
       | Bring batteries into the equation and you can forget about
       | personal VTOL for anything longer than five minute hops.
        
       | [deleted]
        
       | dcchambers wrote:
       | People would love to fly, but in the magic carpet sense. When you
       | look at the dirty and dangerous physical reality of what a
       | jetpack is it's obvious why no one wants one.
        
       | schleck8 wrote:
       | It's so annoying how first generation technology is trashed by a
       | community that should know better.
       | 
       | Of course it will be inaccessible and inefficient.
       | 
       | Where is the spirit of innovation?
        
         | Ekaros wrote:
         | Cursory understanding of physics and chemistry.
         | 
         | Fighting against gravity by exhausting anything is energy
         | inefficient. And there isn't really anything to fix that. It is
         | just fact of universe.
        
       | didip wrote:
       | In the Jetson, a jetpack doesn't have to care about fuel
       | capacity, safety of the pilot, regulations, and cost of
       | production.
       | 
       | But in real life these are legitimate engineering constraints.
       | 
       | Also, if you can scale up a drone to be a 1-person vehicle, I bet
       | it will be safer than jetpack.
        
         | stavros wrote:
         | We have, and as for safety, well... If you think a jetpack is
         | unsafe, wait until you see the blades on a drone.
        
       | Johnny555 wrote:
       | It's not so much that we don't care, but that the current
       | jetpacks are so expensive, hard to operate, low runtime, and so
       | unsafe that they just aren't relevant to most people. I'm not
       | sure that the technology will ever improve enough to make the
       | sci-fi style jetpack that anyone can use.
       | 
       | The only jetpack I've seen that I'd actually be willing to use is
       | the kind that's more like a hose tethered to a water pump that
       | lifts you a few feet above the water, that one looks like it'd be
       | fun, with little chance of injury if it fails.
       | 
       | https://www.jetpackamerica.com/
        
       | jon-wood wrote:
       | They're completely impractical, that jet pack does indeed exist,
       | but there are approximately two people in the world who can
       | safely fly it untethered. Every now and again they'll pop again
       | with "mountain rescue experiment with jet pack" or "Marines
       | demonstrate boarding with jet pack", and every time it's just the
       | creator cosplaying as whatever service he's trying to sell it to
       | this time.
        
         | twobitshifter wrote:
         | Furthermore if you want the sensation of a jet pack, there's
         | the jet lev, which seems much safer. The article mentions that
         | this should only be flown over water on a tether, so what's the
         | benefit over a jetlev?
         | 
         | https://m.youtube.com/watch?v=s00SwPZ_1D0
        
           | Animats wrote:
           | That's like the Flyboard, another water-jet system.[1] That's
           | the world champion flying.
           | 
           | The Flyboard people now have the Flyboard Air.[2] This is a
           | real flying hoverboard, powered by what is believed to be a
           | group of model aircraft jet engines. It's not easy to fly.
           | They require 50-100 hours in the water-powered version before
           | attempting the jet-powered version.
           | 
           | It's very cool, but it's for people who find skateboarding
           | stunts too easy.
           | 
           | [1] https://www.youtube.com/watch?v=0JhUSu8v2N4
           | 
           | [2] https://atlanticflyboard.com/flyboard-air
        
         | badrabbit wrote:
         | Could say the same about the wright brothers in the early
         | 1900s. Longevity of the flight and safe operation can only
         | improve in time. The question is does anyone care. People will
         | be scared of it and if not does it offer anything over cars?
         | It's not like you can fly it over private property , there will
         | be laws that regulate where you can fly it.
         | 
         | Just give me hyperloop tunnels to overlap subways and freeways
         | and I am set. Especially with better bike lanes.
        
           | [deleted]
        
           | BlueTemplar wrote:
           | Aircraft were improved immensely by new materials since then.
           | But jetpacks are still impractical. Might we see the same
           | level of improvements _again_ in the next century ? (And even
           | if we do, wouldn 't "super planes/copters" _still_ be ahead
           | of jetpacks ?)
        
           | ashtonkem wrote:
           | > Could say the same about the wright brothers in the early
           | 1900s.
           | 
           | Yes, you could. But that's not actually an argument that jet
           | packs will follow a same development path, it's just survivor
           | bias in action.
        
             | badrabbit wrote:
             | They may not, I was just saying we don't know what
             | developments will be made in the future.
        
         | mirekrusin wrote:
         | Exactly, we had "smartphones" before iphone as well and nobody
         | did care.
        
           | JKCalhoun wrote:
           | Hmmm... Not sure that Jetpack 2.0 will ever be a thing like
           | the iPhone was.
           | 
           | Helicopters autogyro, planes glide, balloons (usually) lose
           | their lift slowly.
           | 
           | A jetpack, like a rocket, is a thing that has no business
           | flying. Only a large, heavy-handed impulse of energy allow
           | them to oppose gravity. Without altitude and a parachute,
           | there is no Plan B for a jetpack engine failure, loss of
           | fuel, etc.
        
             | ehnto wrote:
             | I think a parachute would be pretty easy to accommodate, at
             | least an emergency one. Maybe it'll still hurt, but cut the
             | pack loose and hopefully you would survive. Not everyone
             | survives helicopter or plane engine failures either.
             | 
             | I certainly don't think jetpacks are a relevant tool for
             | society outside of really niche use cases. If we don't even
             | trust people to fly small drones around the public safely
             | and without FAA regulation and licensing, in what dreamland
             | would we all be able to fly personal jetpacks to the shops,
             | or even recreationally? There are way cheaper, way safer
             | ways to get airbourne as a private aviation enthusiast, so
             | I can see why jetpacks really don't scratch enough itches
             | to have gained popularity.
        
               | marcosdumay wrote:
               | Parachutes have a minimum altitude, and jetpacks really
               | do not push people into flying high. (What is a problem
               | in more ways than that, because most of the things that
               | can make your flight safer need altitude.)
        
           | rhino369 wrote:
           | Blackberries were huge and growing. iPhone definitely
           | expanded the market faster than anyone dreamed. But it was
           | easy to see where the market would go before iPhone.
        
             | mirekrusin wrote:
             | If it was "easy to see" we wouldn't have iphone dominance.
        
               | rhino369 wrote:
               | Easy to see at a high level--phones with web, multimedia
               | support, and app support. Near impossible to guess what
               | exactly what would look like and when.
        
               | Ekaros wrote:
               | The pieces where there already, just good enough product
               | with good enough connectivity was missing. In the end
               | iPhone is nothing more than refined PDA...
        
               | WJW wrote:
               | I just want to point out that global iPhone market share
               | has been hovering between 15% and 20% for years. Android
               | has almost all of the rest. Iphones are not dominant.
        
               | ajb92 wrote:
               | Global market share is one kind of dominance, there are
               | others
        
           | inglor_cz wrote:
           | I had Nokia 7650 in 2004 and I am hopefully not-nobody...
           | these devices, although clumsy, paved the way to the modern
           | mobile ecosystem.
        
             | mirekrusin wrote:
             | Yes, maybe those jetpacks and micro flying machines will
             | pave the way to future electric-scooter-like flying.
        
           | pmontra wrote:
           | A lot of people had smartphones before iPhones. Basically all
           | the 3G phones sold in Europe since 2003. I was working for an
           | operator that got 3 M customers in its first year back then.
           | 
           | Had they a touchscreen as good as iPhone's? Definitely not.
           | Did they had an internet connecting better than iPhone's?
           | Definitely yes because the original iPhone was only 2G.
           | 
           | Anyway, this is only an analogy so let's don't get too much
           | into it.
           | 
           | People don't care about jetpacks because they are crazy
           | dangerous and expensive. This makes them less practical than
           | jumping from a plane with a parachute instead of waiting for
           | it to land.
        
           | Tostino wrote:
           | Early adopters absolutely did care.
        
             | mirekrusin wrote:
             | I'm sure people who fly jetpacks absolutely do care about
             | jetpacks.
        
           | fartcannon wrote:
           | Quite a few of us cared. The teeming millions may not have,
           | but definitely more than nobody.
        
             | mirekrusin wrote:
             | Sure, I meant it in context, obviously some people did
             | care, otherwise they simply wouldn't exist at all, what I
             | meant is nobody = niche = not mainstream by any means.
        
               | fartcannon wrote:
               | I still think that's an understatement. Not that it
               | matters really, but did you forget about the ubiquity of
               | Blackberry's for nearly a decade prior to the iPhone?
        
         | wutbrodo wrote:
         | > Marines demonstrate boarding with jet pack", and every time
         | it's just the creator cosplaying as whatever service he's
         | trying to sell it to this time.
         | 
         | Didn't an actual Royal Marine do this recently, in a training
         | exercise?
         | https://www.popularmechanics.com/military/aviation/a38748085...
         | 
         | This seems like exactly what we'd expect for a technology this
         | new and dangerous, and is certainly a step farther than "the
         | creator is the only one flying it".
         | 
         | EDIT: Per other comments on this thread, apparently the Royal
         | Marine in question _is_ the creator
        
         | MR4D wrote:
         | We solved the stability for drones that cost as little as $20.
         | We'll solve it the same way for jet packs as well.
        
           | ashtonkem wrote:
           | We solved stability for a rigid drone that's symmetric and
           | designed for purpose. That's a lot different than solving for
           | stability for a variable size and weight human that's
           | wriggling around.
        
             | radley wrote:
             | > solving for stability for a variable size and weight
             | human that's wriggling around.
             | 
             | Was solved for Segways. Just need the third axis and some
             | kind of special emergency landing solution (goo + inflato-
             | ball??).
        
               | ashtonkem wrote:
               | No, it's more complex than that. A Segway is counting on
               | the fact that it's sitting on the ground. The force
               | vector on the rider is purely a function of angle. A jet
               | pack has the issue that there is a moveable center of
               | gravity and moveable sources of thrust that feed back
               | into each other. It's doable, I'm sure, but it's also
               | much more complicated than a Segway + another direction.
        
             | MR4D wrote:
             | It's just a digital gimbal. Similar to a light drone in a
             | breeze.
        
         | guerrilla wrote:
         | I was thinking about this while watching a paraglider with
         | propeller yesterday. I was thinking, maybe you could use tiny
         | jets for this, but the question is why would you... this is
         | already perfect [1]. Seems like jetpacks are a solution looking
         | for a problem and at the same time highly impractical.
         | 
         | 1. https://youtu.be/L1Z8YT6w7Rc
        
         | EliRivers wrote:
         | In his defence, Richard Browning, of Gravity Industries, was an
         | actual Royal Marine. Granted, reservist, but they still take
         | and pass the commando course. I ran into him a couple of times
         | in the service; while he's not in anymore, "cosplay" seems a
         | harsh term in his case.
        
         | ehnto wrote:
         | What were we expecting from jetpacks though, really? Is it not
         | more fair to suggest that the past was a little bit naive about
         | what it would take to operate a jetpack? They're still aircraft
         | after all, at the very least you're going to need pilots
         | license.
         | 
         | There's no "bicycle" of jetpacks, you've got three axis of
         | movement and certain death in every direction but up, it's just
         | not a tool that belongs in the every-man's garage.
         | 
         | I think the same can be said for the past's perception of what
         | flying cars would be like. You don't see your average joe
         | flying a helicopter to work, for the very same reasons you'll
         | never see personal flying cars be ubiquitous.
        
           | everdrive wrote:
           | > There's no "bicycle" of jetpacks, you've got three axis of
           | movement and certain death in every direction but up,
           | 
           | Arguably, this could exist, and is a self-stabilizing battery
           | powered drone.
        
           | falcolas wrote:
           | > What were we expecting from jetpacks though, really?
           | 
           | Drones, in the form of a jetpack.
           | 
           | A little joystick in each hand with DJI levels of KISS, and
           | with the same DJI "Help I'm out of control!" button too.
           | Probably "return to home" too.
           | 
           | We don't/can't have that, because there's no servo-mechanical
           | joints to be controlled in the referenced rocket pack system.
        
           | scythe wrote:
           | >There's no "bicycle" of jetpacks, you've got three axis of
           | movement and certain death in every direction but up, it's
           | just not a tool that belongs in the every-man's garage.
           | 
           | There is a perfectly good flying vehicle that can be flown by
           | an ordinary person with a reasonable amount of training; it's
           | called a powered paraglider. However, it has the disadvantage
           | that it is _very_ large, and if the weather is not favorable,
           | you can 't fly.
           | 
           | The analogy with a car would be "road sometimes spontaneously
           | turns into scree", and it would be very hard to design a car
           | that can cope with that.
        
           | andrei_says_ wrote:
           | To be completely honest my expectations of jet packs were
           | modeled by cartoons.
           | 
           | I am admitting this publicly as a reminder to myself and
           | others for the fact that for the public, the process of
           | writing software is modeled by scenes of hackers in Hollywood
           | movies.
        
           | thereddaikon wrote:
           | I feel that improved control systems could go a long way to
           | making them more controllable. Look at RC aircraft, they used
           | to take a lot of practice to fly and even when mastered
           | required so much focus that they weren't useful for anything.
           | But now drones practically fly themselves and instead of
           | "flying" the drone, the pilot really just tells it where to
           | go. The flight software figures out the rest.
           | 
           | There's no reason the same principles can't be applied to jet
           | packs. Add a gyro or two, gps etc to give it the data it
           | needs and the pilot should have a much easier time.
           | 
           | The more difficult to solve problem is with endurance. They
           | are only good for 10s of seconds of powered flight.
        
           | sbierwagen wrote:
           | >certain death in every direction but up
           | 
           | Up is also certain death, if you're not carrying bottled
           | oxygen.
        
           | tshaddox wrote:
           | > They're still aircraft after all, at the very least you're
           | going to need pilots license.
           | 
           | I think a reasonable interpretation of the _promise_ of
           | jetpacks would be more like the  "ultralight vehicles"
           | category (as it's called in the United States). These
           | vehicles require no registration or pilot certification. Some
           | are fairly traditional rigid airplane designs (just very
           | small and lightweight), but the category also includes
           | powered paragliders (AKA paramotors) and some of the smaller
           | powered parachutes.
           | 
           | Where I grew up in the US these were fairly common to see in
           | the air, and no one thought it was odd that they didn't
           | require a pilots license. Perhaps for many people in many
           | areas the regulations or different, and it strikes them as
           | absurd to fly aircraft without a license?
        
             | Grimburger wrote:
             | Ironically where I live, it's far simpler to get a private
             | pilot's license than a provisional car license.
             | 
             | It takes 25 hour in a plane to get a recreational license,
             | and 120 supervised hours logged in a car, for people who
             | don't have a relative to do the supervision and need to pay
             | and instructor, the cost comes out more than getting a
             | pilots license.
             | 
             | Once that's done to be allowed on the road alone, they need
             | to get their 2nd provisional license a year later, then
             | full car license a year again after that, with additional
             | tests along the way.
        
           | dioxide wrote:
           | rocket man.
        
           | sandworm101 wrote:
           | >> There's no "bicycle" of jetpacks
           | 
           | Grab any drone with a 200kg capacity (they do exist), hang a
           | lawn chair under it, and take to the sky. That's probably
           | safer. Jetpacks as a concept might get overtaken by the small
           | helicopters we today call drones.
        
             | ehnto wrote:
             | But would you let a child operate the drone chair? I think
             | you're right that drones would be some kind of safer, I
             | think it's the more likely of the two technologies to work
             | for personal aviation.
        
               | sandworm101 wrote:
               | If you want to get to work in the morning, then a drone
               | full of autopilots and AI is the safe and reliable way to
               | fly across the city. But for living the Ironman fantasy
               | of sailing through windows then you'll need a jetpack
               | with all the associated dangers.
        
             | NeuNeurosis wrote:
             | Funny you mention that. I just saw the below on reddit the
             | other day.
             | 
             | https://explorersweb.com/jetson-one-giant-passenger-drone/
        
               | echelon wrote:
               | Put a giant pre-inflated airbag around it and that might
               | not be unreasonable.
        
               | Animats wrote:
               | That's a nice piece of hardware.
               | 
               | There are other big, people-carrying drones. eHang was
               | probably the first, in 2016. They've actually sold a few.
               | Price is above US$300K. They routinely fly above cities.
               | Like everybody else, they're battery-limited. Their limit
               | is about 30 minutes.
               | 
               | All those un-shrouded spinning blades at low height are
               | worrisome.
        
           | dclowd9901 wrote:
           | And yet, it's quite easy to fly a drone in simple mannerisms.
           | The UX failure of the jet pack is refinement in software,
           | which drone makers have already figured out.
           | 
           | The real issue is, with an 8 minute flight time, it's good
           | for demonstrations and that's it.
        
           | fishtoaster wrote:
           | I feel like you could describe cars the same way:
           | 
           | You've got two axis of movement at 60mph. Stray a couple feet
           | left or right and you die in fiery inferno. Stop too fast or
           | too slow, same deal. Maybe appropriate for highly-trained
           | specialists, not for every-man's garage.
           | 
           | My point is not that "cars are death machines no one should
           | own," although there are certainly those who hold that
           | opinion. Rather that inherently dangerous things can be made
           | relatively safe with enough systems around them: roads,
           | signs, traffic laws, licenses, seatbelts, and so on.
        
             | somehnacct3757 wrote:
             | The third axis adds the risk of a gravity impact to every
             | accident. Maybe it's solvable with some kind of failproof
             | parachute system, I dunno. I wouldn't invest in it.
             | 
             | Showing that cars are scary doesn't disprove that flying
             | cars are more scary
        
             | kiliantics wrote:
             | I think it was a mistake to allow just about anyone behind
             | the wheel of a car. It results in upwards of 1 million
             | deaths per year, that's more than malaria. And that's not
             | including deaths attributed to air pollution.
        
             | silvestrov wrote:
             | The big difference is that cars have brakes and that coming
             | to a full stop will avoid most crashes.
             | 
             | There is no good "emergency braking" for jetpacks, there is
             | not even "autorotation" as there is for helicopters.
        
             | nerdponx wrote:
             | I think maybe the problems are: 1) the extra axis of
             | movement means more operating complexity, and 2) there is
             | no equivalent of "5 mph in a parking lot" on a jetpack,
             | either you're flying or you're not.
        
             | bryanrasmussen wrote:
             | yes but the way to make cars safe is to - seriously
             | constrain their movements (all cars here move in this
             | direction, you can get off here, you can get on here etc.
             | ), have different types of licenses for different kinds of
             | cars, and limit their speeds based on location.
             | 
             | Jetpacks, and the flying car, have more possible ways to
             | move.
             | 
             | The Jetsons used to show the flying car working the way the
             | normal car did - highways in the sky - that's basically the
             | way it would have to work to be made safe, as long as there
             | are any sizable amount of users of the jetpack or flying
             | car.
             | 
             | The jetpack has of course other hazards associated with it
             | such as the engine being really close to the human
             | operating it with significantly less shielding than one has
             | on the car.
             | 
             | on edit: I think there might have been problems with the
             | car in some Jetsons and George had to parachute to safety,
             | arms crossed and a seriously miffed expression on his face.
        
               | bryanrasmussen wrote:
               | So all that said - what would be required of the flying
               | car for it to work well enough to supplant the car? (not
               | the jetpack, that will at best be the skateboard of the
               | sky)
               | 
               | 1. It would have to be significantly faster, able to go
               | longer (makes sense this would be the case because
               | obviously you can fly quicker than you can drive so I
               | assume this benefit will be a gimme, but it has to be
               | significant for people to care. If you can make the
               | flight to grandma's house in 3 hours instead of 8 there
               | would be interest)
               | 
               | 2. It would have to not cost very much more to own or to
               | run.
               | 
               | 3. It would have to not be any less safe for drivers than
               | it currently is to drive - at the beginning this might be
               | the case because less drivers means more safe maybe.
               | 
               | 4. there would probably have to be significant safety
               | features built in to keep flying cars from causing
               | catastrophic damage if they failed - this seems to right
               | there make it impossible because it has to not cost much
               | more than a normal car.
               | 
               | 5. There would probably have to increase in automation of
               | cars to be able to detect when something wrong, when
               | someone breaking flight rules etc.
               | 
               | 6. no internal combustion engine flying cars, because a
               | falling car with internal combustion engine is also a
               | potential bomb.
               | 
               | so what are the benefits - we've already mentioned 1 but
               | are there others?
               | 
               | Conceivably with a mass movement to flying cars instead
               | of cars the infrastructure of cars would no longer be
               | needed or need to be maintained. A utopian vision would
               | then be that all that land that is currently big packed
               | freeways get converted to parks etc. although a cynical
               | vision would say oh nobody would want to pay for that and
               | they turn into dystopian hellholes and kids go there to
               | get eaten by coyotes.
               | 
               | Possible benefit #3 - to make safe have to have much
               | routes for everything but given that we have all the sky
               | conceivably there could be more routes, including
               | emergency routes that would be left to emergency services
               | or people registered for a possible quick route (quick
               | routes to hospital for birth etc.) All of this of course
               | implies flying cars with effective computer surveillance
               | of drivers.
               | 
               | So I see these benefits to flying car - 1. quicker longer
               | trips enabled. 2. No longer need driving car
               | infrastructure 3. possible solutions to congestion are
               | still available with flying car.
               | 
               | But does that mean it is doable.
               | 
               | I think the needed functionality points basically cancels
               | out it ever working but maybe I am pessimistic, although
               | I do think that now we are actually getting to the point
               | where the necessary prerequisites for flying cars are
               | starting to be built - specifically good electric cars
               | and driving automation and services (but way early for
               | that, flying cars in 100 years at this rate)
        
             | edaemon wrote:
             | Jetpacks don't have brakes. Once you start moving, coming
             | to a stop is very difficult or very harmful. You have to be
             | a highly trained specialist to operate a jetpack _at all_ ,
             | while you can gently learn to operate a car.
        
             | nwienert wrote:
             | I think this comment is reasonable and the replies to this
             | comment are filled with bad takes.
             | 
             | Currently designed Jetpacks don't have brakes, or any
             | safety features really, but that's just a lack of
             | development.
             | 
             | You could easily think of hundreds of safety features that
             | would make Jetpacks in a distant future seem pretty safe,
             | from auto pilot/recovery features, automated object
             | detection and avoidance, body suits with built in airbags,
             | better designed packs that give things like 100x better
             | articulation control, built in parachutes, the list could
             | go on forever really.
             | 
             | Meanwhile cars actually have additional dangerous
             | properties: being stuck in very confined tracks where any
             | other user errors affect you, limited visibility, and a
             | massive amount of heavy metal surrounding you.
             | 
             | I don't see why Jetpacks couldn't be as safe as a cars
             | given they had an equal amount of investment into safety as
             | we see modern cars. And to answer the article as to why
             | they aren't popular, it's pretty easy to see that they just
             | kind of suck as they are now, they need improvements in
             | nearly every dimension.
        
               | outworlder wrote:
               | The reason they are not popular is that we don't have a
               | practical power source. Flight times are measured in
               | minutes. And practical ones that could be used by anyone
               | would be much larger (think VTOL hang glider, not Bobba
               | Fett).
               | 
               | Even with a practical power source, you know have an
               | immense amount of energy stored right next to your body.
               | You need to be able to direct said energy in a safe way.
               | Good luck.
               | 
               | There's only so much airbags can do. Imagine where you
               | would locate those airbags. Cant be pressed against the
               | body either (airbags can cause horrible injuries).
               | Parachutes won't help close to the ground.
        
               | iainmerrick wrote:
               | I think there are a couple of key differences that you're
               | underplaying.
               | 
               | First, for usage of cars in society, there's a nice
               | gradual curve where an early slow unreliable car is still
               | somewhat useful, and a faster car is a bit more useful,
               | etc, and that's what allowed them to get off the ground
               | (as it were). There's a vastly higher threshold before
               | jetpacks start being usable and useful.
               | 
               | Second, cars are relatively fail-safe in that if you take
               | your foot off the accelerator the car will coast to a
               | halt. Lots of cars can easily come to a safe stop
               | together -- traffic jams are bad but not immediately
               | life-threatening.
               | 
               | Jetpacks aren't nearly as failsafe because if you stop
               | flying you need to land (or more likely, crash-land).
               | 
               | Planes have the same two advantages over jetpacks,
               | because even a slow or unreliable plane is useful because
               | it can carry cargo; and most planes can glide a bit which
               | helps reduce the risk of crash landings.
        
               | notahacker wrote:
               | Apart from anything else, the minimum viable car was
               | pretty much as safe as modern cars (probably actually
               | harder to kill yourself in the original car with its
               | 10mph top speed), and just as intuitive to operate
               | safely. The safety advances came later to deal mostly
               | with problems which arose later (speed and other cars and
               | boredom from long distance low effort driving)
        
             | pdonis wrote:
             | _> inherently dangerous things can be made relatively safe
             | with enough systems around them: roads, signs, traffic
             | laws, licenses, seatbelts, and so on._
             | 
             | While this is true, the issue is that what is required for
             | "enough" can vary very widely. In particular, what would be
             | "enough" for jetpacks (and flying machines more generally)
             | is a lot more than what experience has shown to be "enough"
             | for cars. Some indications of why that is are the frequency
             | of airplane accidents involving experienced pilots, who
             | have had a lot more training on how to fly a plane than
             | anyone gets on how to drive a car, and also the amount of
             | time and effort and the level of continuing human
             | supervision required to keep commercial air travel as safe
             | as it is, even though that also involves experienced pilots
             | and has the support of many complex systems.
        
             | moralestapia wrote:
             | Your engine dies while driving, nothing happens.
             | 
             | Your engine dies while flying, good luck, pal.
        
               | outworlder wrote:
               | > Your engine dies while flying, good luck, pal.
               | 
               | In a jetpack, yes. Good luck. Drone, good luck too.
               | 
               | Airplane? You glide down.
               | 
               | Helicopter? You autorotate down.
        
               | nwienert wrote:
               | If only we had an invention that used air resistance to
               | slow falls...
        
               | ben_w wrote:
               | Parachutes don't work well enough for this hypothetical.
               | 
               | Are there full body airbags? Could that even work?
        
               | HeyLaughingBoy wrote:
               | > Are there full body airbags? Could that even work?
               | 
               | Let me know if you find out. I have _got_ to get one :-)
        
               | notahacker wrote:
               | If only that invention wasn't supposed to be strapped to
               | the same part of the person's anatomy as the jetpack,
               | with the result being that no practically working
               | implementation combining the two exists...
        
               | nwienert wrote:
               | That's not an intractable problem by a mile.
        
               | notahacker wrote:
               | It's also not the solved problem your snark implied. I
               | mean, someone's been working on it for decades and his
               | solution is _fly over water as much as possible_!
               | 
               | (As other posters have alluded to, parachutes won't save
               | you at low altitudes. In the mean time, it's further
               | weight on your back on a device which is already
               | difficult to control, and not really optimal for
               | releasing next to jets of hot kerosene either)
        
               | r00fus wrote:
               | Do parachutes help when you lose control 50ft off the
               | ground? Deploy time is probably too short. Also lateral
               | speed may be fatal enough with a jetpack.
        
               | chipsa wrote:
               | Rocket deployed parachute. Kinda like https://en.wikipedi
               | a.org/wiki/Cirrus_Airframe_Parachute_Syst...
               | 
               | Speeds up deploy time by making the deploy happen,
               | instead of waiting for gravity/airflow to deploy it.
        
               | nwienert wrote:
               | Body airbags or similar would likely work for lower
               | altitude.
        
             | ehnto wrote:
             | It's not really a "new frontier being misunderstood"
             | though, it's very clear what it's value proposition is, and
             | it's also clear from our history with aviation so far, what
             | the challenges are. As I said in another comment, we don't
             | even trust people to fly small drones without certification
             | and FAA regulation, there's good reason for that, being in
             | the air is nothing like being on a road.
        
               | jancsika wrote:
               | To answer your question-- people in the past were
               | expecting what has happened with small drones. Namely,
               | that there'd be a metric fuckton of them, and that
               | regulators would have to scramble to keep order before
               | angry townsfolk began firing their rifles up at in the
               | sky at them.
        
               | marcosdumay wrote:
               | Yeah, people in the past overestimate how eager people
               | are to take obvious risks.
               | 
               | To be fair, the eagerness of people to do activities that
               | feel risky but actually aren't makes that prediction
               | harder than it looks at first.
        
               | InitialLastName wrote:
               | > we don't even trust people to fly small drones without
               | certification and FAA regulation, there's good reason for
               | that, being in the air is nothing like being on a road.
               | 
               | We don't trust people to operate cars on a road without
               | DMV certification, FMVSS regulations, and a substantial
               | amount of liability insurance.
        
             | hunterb123 wrote:
             | I feel somewhat in the middle between both of your
             | opinions.
             | 
             | The "average joe" in some regions may not fly regularly,
             | but around here there's many farmers with Cessnas that do
             | routine work.
             | 
             | Currently, if you have a use for it and are somewhat
             | competent, it's practical to fly and not out of reach for
             | the common man.
             | 
             | But in no near future do I see them reducing the
             | restrictions, flight hours, air traffic protocols, etc.
             | 
             | That being said, I don't see much practicality for a
             | jetpack other than sport or rescue.
        
               | ehnto wrote:
               | That's a big part of my reasoning, there are some
               | fundamental impracticalities to personal aviation that
               | limit it to particularly niche use cases. Those don't
               | really change just because it's a flying car or jetpack.
               | 
               | I can of course picture a world where there are automated
               | skyways, and electric AVs guide themeselves from abode to
               | shopping mall airport, I'm not without imagination. But
               | I'm not hopeful.
        
             | jabbany wrote:
             | Actually, the high level question in here is quite
             | interesting (and has even been discussed in some sci-fi).
             | 
             | Humans evolutionarily think about movement with a 2
             | dimensional mindset because for much of our history we only
             | needed to think about 2d movement. It's why even modern
             | flight is centered around the idea of stacking multiple 2d
             | environments (via elevation / flight levels) and then just
             | ignoring that 3rd dimension for the most part.
             | 
             | This is why something like a car is operationally intuitive
             | -- humans don't need training to quickly pick up the
             | interface for one, even a kid could operate a 2d vehicle.
             | The systems around them mainly manage the risk around
             | _conflict_ introduced by having multiple actors.
             | 
             | This is also where a plane (or submarine, or jetpack) is
             | fundamentally different. The systems around those need to
             | manage not only conflict but also our sensory deficiencies.
             | It's very easy to get disoriented in 3d movement (it's very
             | easy to lose the ability to tell up from down) and there
             | have been plenty of plane crashes due to this. That's why
             | pilots need to infer their orientation from instruments
             | rather than just their senses. That's also why flying cars
             | and jetpacks are not widely available -- the amount of
             | training just to operate such devices _alone_ is already
             | very high, let alone having to manage conflict in addition
             | to that.
        
               | marcosdumay wrote:
               | > It's why even modern flight is centered around the idea
               | of stacking multiple 2d environments
               | 
               | That's for sharing the space. It's not only a set of
               | stacked 2D environments, those are also divided in road-
               | like spaces, with a limited number of junctions.
        
               | orthoxerox wrote:
               | Cars are mostly 1d vehicles in practice, unless they are
               | bumper cars. We try really hard to minimize 2d
               | interactions between cars by stacking multiple 1d
               | environments (lanes) and ignoring the 2nd dimension for
               | the most part. Where we cannot ignore it we try to make
               | it safe by adding turn lanes, roundabouts, traffic lights
               | or building interchanges.
        
               | eshack94 wrote:
               | You raise some interesting points here that I had not
               | previously considered with respect to flight/submarines
               | vs. land vehicles/boats. That third dimension must
               | introduce a lot of cognitive load, even before conflict
               | of other vessels/aircraft enter the scene.
        
               | jabbany wrote:
               | There's some sci-fi (that I cannot remember off the top
               | of my head) that actually uses this as a plot point.
               | 
               | I may be misremembering, but the idea is there's a
               | special race of humans who have continued to evolve
               | living in low gravity (space) environment, and the
               | terrestrial human (those living on planets) governments
               | would hire them as space mercenaries because they're at a
               | huge advantage when it comes to 3d combat compared to
               | training some terrestrial guy.
        
               | hedgewitch wrote:
               | You don't mean The Expanse, do you?
        
               | at_a_remove wrote:
               | This was a limitation of Khan in the second Star Trek
               | film.
               | 
               | There is a trilogy of books written covering Khan's life
               | and it very subtly shows why Khan has this difficulty,
               | but never points at it and shouts.
        
               | usefulcat wrote:
               | I had always thought of that line as metaphorical ("two
               | dimensional thinking"), but that's a very interesting
               | idea, and fits well with the final battle that
               | immediately follows it.
        
               | forgetbook wrote:
               | Ender's game; maybe not what you're referring to (based
               | on your description), and also uses 3d navigation as a
               | plot point ('The enemy is down')
        
               | dTal wrote:
               | >It's why even modern flight is centered around the idea
               | of stacking multiple 2d environments (via elevation /
               | flight levels) and then just ignoring that 3rd dimension
               | for the most part.
               | 
               | Generally you want to fly at a constant altitude because
               | climbing and descending require energy transfers. Humans
               | have little trouble coping with the concept of
               | 3-dimensional flight, indicated by the enduring
               | popularity of combat flight simulators, but aircraft that
               | aren't built for combat physically struggle (and even in
               | those that are, such flight demands careful energy
               | management).
        
               | jherdman wrote:
               | > Humans evolutionarily think about movement with a 2
               | dimensional mindset because for much of our history we
               | only needed to think about 2d movement.
               | 
               | Citation required? If you hang out with a child you
               | quickly discover that their world is quite three
               | dimensional. Heck, climbing is a fast growing sport.
               | Again, three dimensional. We're made to run, jump, and
               | climb. Three dimensional.
        
               | rpdillon wrote:
               | I've worked for several years with children, and have
               | also piloted aircraft. 3D is _tough_, at least for me.
        
               | aaaaaaaaaaab wrote:
               | >Heck, climbing is a fast growing sport. Again, three
               | dimensional.
               | 
               | Ummm... no? The surface of a mountain is still two
               | dimensional.
        
               | lolc wrote:
               | A mountain surface is 2.5 dimensional. If you allow for
               | the fractal part.
        
               | brianr wrote:
               | Climbing is two-dimensional, not three - on any given
               | part of a wall or tree, you can move left-right and up-
               | down but not in-out.
        
               | wahern wrote:
               | 1) People, especially kids, jump between and across
               | structures all the time.
               | 
               | 2) Humans are great at throwing and catching objects,
               | even with complex, changing trajectories--bouncing off
               | walls, etc.
               | 
               | 3) We have two innate senses that are clearly adapted to
               | 3 dimensions: stereoscopic vision and proprioception.
               | 
               | What makes those behaviors relatively intuitive is
               | constant acceleration. In a sense constant acceleration
               | makes everything 2D. (Or 2.5D?) When humans need to track
               | objects which independently accelerate along 3 axes, then
               | there's a much stronger case for an environment alien to
               | humans. (Counter point: hunting birds, though I believe
               | hunters prefer to take their shot when birds are
               | beginning or ending their flight. But notably the most
               | salient characteristic there is acceleration, not merely
               | relative movement in 3D space.)
               | 
               | Yeah, the more that I think about it, you get much more
               | predictive power by emphasizing acceleration, not spatial
               | dimensionality. And I don't think that's being pedantic;
               | the distinction matters. When you look at studies of how
               | the brain processes motion, constant acceleration (at
               | least along 2 of 3 axes, unless/until hitting another
               | object) is often one of the key assumptions that seems to
               | be built into our cognition.
               | 
               | For example, tracking many objects moving independently
               | in 3D space is pretty darned difficult for
               | humans.[citation needed] But that probably has more to do
               | with relative motion (and thus relative acceleration)
               | than with the number of dimensions as a human can track
               | _two_ such objects surprisingly well, especially if they
               | have a third, fixed reference independent from
               | themselves.
               | 
               | Would be curious to compare & contrast studies of spatial
               | cognition between marine animals and terrestrial animals,
               | though.
        
               | sirspacey wrote:
               | Love this framing. Feels like the three body problem is
               | relevant.
        
               | pwinnski wrote:
               | Kids don't act in true 3-D, they act in Doom-like 2-D. It
               | gives the appearance of 3-D, but the Z-axis is barely off
               | zero. Climbing swaps X and Z, but is still 2-D.
               | 
               | If it helps, think of what everybody else is calling
               | "3-D" as "no obvious primary axis."
        
               | jabbany wrote:
               | From NASA: https://www.nasa.gov/audience/forstudents/9-12
               | /features/F_Hu...
               | 
               | "When there is no visual input as is common in many
               | flight situations, we rely more heavily on our vestibular
               | sense for this information. However, in flight and in
               | space, our vestibular system, _which is designed to work
               | on the ground in a 1g environment_, often provides us
               | with erroneous or disorienting information."
               | 
               | We have a system to somewhat understand and orient
               | ourselves in 3d obviously, but it has quirks because
               | evolution tuned it to work best on the ground + assuming
               | 1G of gravity as "down".
               | 
               | Orienting in 3d is not intuitive for us. We can do it but
               | we need a _lot_ of help to do it safely.
        
               | ipaddr wrote:
               | Your quote talks about 1g gravity not that 3d is not
               | intuitive. A 3d world with 1g could be intuitive.
        
               | [deleted]
        
               | Afton wrote:
               | > __on the ground__ in a 1g
        
               | ouid wrote:
               | Planes and submarines treat down as special because down
               | is genuinely special. We would have some other
               | abstraction if this were not the case.
        
               | jabbany wrote:
               | It _is_ special but we cannot perceive it correctly. We
               | do not have an absolute sense of "down" (and our absolute
               | sense of "forward" and "backward" are based on a assuming
               | fixed "down").
               | 
               | We sense "down" based on assuming that 1G of acceleration
               | is the "down" position. This is fine if you're
               | stationary. This is fine if you're moving in 2d. But
               | accelerate in 3d and all of a sudden you can get
               | completely disoriented because the "down" you're latching
               | on to could be any acceleration vector.
               | 
               | We _can_ manage this, but it is an acquired skill and we
               | need instruments to help us. Pilots (and especially
               | fighter pilots or astronauts who truly experience a lot
               | of 3d acceleration) need to train for years to acquire
               | this skill.
               | 
               | Can you imagine training an average person years just to
               | _use_ a jetpack? That's why we have jetpacks and yet most
               | people don't care.
        
               | lazide wrote:
               | Most of the astronaut and pilot training on this, btw, is
               | to completely ignore what our internal intuition is and
               | use instruments and direct math - for the reason you're
               | talking about, but also because especially at the
               | astronaut level ALL intuition related to speed,
               | direction, etc. is generally wrong. for pilots it's often
               | only _mostly_ wrong, but using intuition and flying IFR
               | is not going to work for long.
               | 
               | For an astronaut in orbit, going 'up' means accelerating.
               | Going 'down' means slowing down. Going sideways (in the
               | way we typically think of it) involves changing velocity
               | in least 2 vectors twice, etc.
        
               | hateful wrote:
               | The answer here is what we have in drones. Drones can
               | stay perfectly still in the air now. A flying car or
               | personal "jet pack" would be the same. The usable system
               | would provide all the stabilization of a drone and your
               | controls would be just that of a car, with a separate
               | setting for altitude.
               | 
               | And just like cars, you wouldn't be flying it randomly,
               | we'd have to build "lanes" at different heights, etc. You
               | don't drive your car randomly through buildings. In fact,
               | connecting to a network and having it fly for you would
               | be the most likely scenario.
               | 
               | Not to say that there wouldn't be "free flight" parks
               | around.
        
           | mountainriver wrote:
           | I donno the mandolorian maybe?!
        
           | jvanderbot wrote:
           | Someday, helicopters will operate like video games, due to
           | complete flight software stabilization and abstraction of the
           | horrifically complicated control surfaces. This is already
           | starting. But uptake is slow[1]
           | 
           | At that time, we can revisit jetpacks and use onboard
           | software to completely abstract the horrifically complicated
           | control problem.
           | 
           | 1. https://aviation.stackexchange.com/questions/23977/why-
           | arent...
        
             | ehnto wrote:
             | I agree and it's pretty incredible, but I think to enable
             | popularization of it as personal transport you'd need to
             | abstract the pilot away entirely. Automate the whole
             | journey, from a system that's aware of all other journeys.
             | That still can't account for all dangers, but at least
             | people wouldn't be flying into each other at 100mph
        
             | outworlder wrote:
             | At 25k USD for the cheapest helicoper blade, I don't see
             | them getting more popular even if they become trivial to
             | fly.
             | 
             | Tiny jet turbines are expensive too.
        
               | BlueTemplar wrote:
               | Wouldn't mass manufacturing significantly drive these
               | costs down ? Fuel costs however...
        
           | ThrustVectoring wrote:
           | > They're still aircraft after all, at the very least you're
           | going to need pilots license.
           | 
           | The FAA is amenable to allowing people to operate small
           | personal for non-commercial purposes _without_ a license. If
           | you do not take passengers and do not operate it in time,
           | place, and manner that creates a hazard for others, there 's
           | a very real "if you kill your own damn self that's your
           | problem" regulatory mentality.
           | 
           | What you actually need a license for is to exceed
           | speed/weight/fuel limitations designed to ensure these
           | conditions. If you're going for a part 103 ultralight craft,
           | that's 55 knots / 254 pounds / 5 gallons of fuel. Might be
           | hard to design a usable jetpack under these constraints.
        
           | outworlder wrote:
           | > What were we expecting from jetpacks though, really? Is it
           | not more fair to suggest that the past was a little bit naive
           | about what it would take to operate a jetpack? They're still
           | aircraft after all, at the very least you're going to need
           | pilots license.
           | 
           | You need a pilots license, but you don't need fine motor
           | coordination skills across your entire body PLUS a lot of
           | core strength, in addition to all the problems with moving in
           | 3d.
           | 
           | For this 'jetpack' you are essentially balancing your weight
           | between your back and arms. If you get it wrong for a split
           | second, you'll kiss the ground. It's inherently unstable and
           | tiring since you have jet turbines strapped to your arms.
           | 
           | An aircraft is stable. Let go of the controls and it will
           | keep flying.
           | 
           | The closest aircraft comparison would possibly be with a hang
           | glider, except even there your weight is supported and you
           | are essentially just shifting it around.
           | 
           | Many jetpacks in fiction were envisioned to work more like
           | drones. Tell it where to go and it would do the rest. Iron
           | Man would be similar to this thing, except it is described as
           | a fully mechanized suit (plus artificial intelligence), which
           | magically takes care of some of these problems.
           | 
           | Ultimately, 'jetpacks' will probably never exist. There's an
           | inherent physics limitation when trying to strap a whole
           | human body to the side of something small (and generally
           | depicted as being strapped on your back, Bobba Fett style).
           | The center of mass is off.
        
             | KineticLensman wrote:
             | > since you have jet turbines strapped to your arms
             | 
             | So soldiers that use them would need guns strapped to their
             | feet?
        
             | dreamcompiler wrote:
             | The stability issues could easily be fixed with more
             | closed-loop control. The much more serious issues are heat
             | and the limited fuel supply.
        
               | jonathankoren wrote:
               | Agree. This is the same reason why I'm skeptical on
               | flying cars. There's so many fender benders. I don't want
               | a Jetta crashing through my roof.
               | 
               | Sure, general aviation is safer than driving (e.g. less
               | accidents per vehicle, and less accidents per hour/mile),
               | but general aviation is more dangerous than commercial
               | aviation. I suspect there's something going on with
               | maintenance, training, and available safety features.
               | Seems like lowering the barrier of entry to flying is
               | simply going to increase the accident rate because
               | there's just more less skilled people flying.
               | 
               | Of course most flights crash on takeoff and landing, and
               | conceivably that would be automated, so maybe I'm just
               | being paranoid. Still seems impractical, if for no other
               | reason space restrictions on the ground.
        
               | lazide wrote:
               | Commercial aviation gets to pick from the cream of the
               | crop and fully professionalizes it's pilots - it's all
               | they do, all the time. That means staying current
               | (keeping habits fresh, remembering key details, etc)
               | happen easier.
               | 
               | Considering how low the frequency is for your your
               | typical GA pilot, it's honestly a wonder it works as well
               | as it does.
        
               | carabiner wrote:
               | GA is actually less safe than driving. It's about as safe
               | as riding a motorcycle:
               | https://inspire.eaa.org/2017/05/11/how-safe-is-it/
               | 
               | GA aircraft crash every day in the US. They don't make
               | the news outside of aviation circles because only 1-2
               | people are affected. Often the occupants survive.
        
             | rictic wrote:
             | If battery tech continues to improve at current rates then
             | certainly electric jetpacks will be possible and practical,
             | if there's still demand (and we don't destroy ourselves one
             | way or another). Without doing the math though it might be
             | many decades.
        
               | mdavidn wrote:
               | Unlikely. The specific energy of jet fuel is more than 40
               | times that of batteries, and I don't see batteries
               | improving by an order of magnitude. A jetpack would need
               | 40 times more battery mass than fuel to produce the same
               | thrust for the same duration. Of course, the weight of
               | the batteries require even more thrust...
        
               | earleybird wrote:
               | Nailed it.
               | 
               | Even in cars where there they do a bunch of gliding
               | (rolling) batteries are just becoming plausible (looking
               | back over time).
        
               | alisonkisk wrote:
        
             | XMPPwocky wrote:
             | "There's an inherent physics limitation when trying to
             | strap a whole human body to the side of something small
             | (and generally depicted as being strapped on your back,
             | Bobba Fett style). The center of mass is off."
             | 
             | While obviously wasteful and goofy, there's always the
             | option of putting an _upwards-pointing_ (i.e. pushing down)
             | thruster at the rear of a jetpack like a lever arm.
        
               | asdfasgasdgasdg wrote:
               | I was thinking that eventually they could design some
               | kind of powered attachment between the arm pods and the
               | backpack. It would accentuate your desired movement while
               | relieving stress. Maybe they could control it with a
               | Neuralink implant so that there won't be accidental
               | movements due to buffeting. Then if you had that you
               | could build an AI to make it mostly user-error-proof.
               | 
               | To be clear, this is all pie in the sky nonsense, but
               | it's fun to think about. It would _still_ be terribly
               | impractical, but maybe it could be made reliable enough
               | that using it over land would not be immediately fatal to
               | most ordinary people who would want to try it.
        
               | rowathay wrote:
               | " this is all pie in the sky nonsense"
               | 
               | Nah, only the Neuralink part.
        
             | mbrameld wrote:
             | > An aircraft is stable. Let go of the controls and it will
             | keep flying.
             | 
             | That's true for most fixed-wing aircraft, but it's
             | certainly not true for most rotor-wing aircraft. I'd
             | estimate you've got about a second, if you're lucky,
             | between letting go of the cyclic in a Robinson R22 and
             | unrecoverable loss-of-control.
        
               | evilos wrote:
               | Even with loss of power for rotary wing aircraft don't
               | you have the option to auto rotate to the ground?
        
               | kevin_thibedeau wrote:
               | You have to have enough forward speed. Auto rotation is a
               | joke in a real emergency most of the time.
        
               | elpatoisthebest wrote:
               | The problem with Robinson helicopters specifically (older
               | R-22 & R-44 more than most) is their very low mass rotor
               | system, which results in very low inertia. The time you
               | have to recover is significantly shorter than other high
               | inertia systems on other helicopters.
               | 
               | Their very low cost makes them pretty common for schools
               | and instruction in general, but the low inertia (and
               | resultant fatalities early in its operation) was
               | significant enough that the FAA requires a Robinson
               | specific endorsement.
        
             | lazide wrote:
             | I wouldn't be so sure. Fundamentally this is a control
             | input/feedback/positioning/power problem - one we don't
             | currently know how to model or control in an automated
             | fashion.
             | 
             | With the right mental model and control/power systems, it
             | wouldn't have to be much different from riding a unicycle.
             | Helicopters have similar issues (it's a bit like balancing
             | a spinning bowling ball on the end of a stick in practice -
             | yet many people are licensed and safe helicopter pilots)
             | 
             | I'm guessing it's something that not everyone can do, but
             | something a large percentage of people (20%+?) can do if
             | they spent the time learning and it was systematized
             | usefully.
        
           | funkaster wrote:
           | I think the part that's missing (besides the knowledge and
           | understanding of the operation in the airspace) is enough
           | (automatic) assistance that its manipulation can be done by
           | someone with the sake skills that any GA pilot could have.
        
           | jayd16 wrote:
           | I think we probably expected something closer to a motorcycle
           | as far as danger and accessibility.
        
         | chrisseaton wrote:
         | > the creator cosplaying as whatever service he's trying to
         | sell it to
         | 
         | That guy is an actual Royal Marine Commando - he's not
         | cosplaying.
        
           | ch4s3 wrote:
           | I think the point is that when you see demos, it's always him
           | dressed up as a marine, mountain rescuer, etc and not someone
           | else.
        
             | hammyhavoc wrote:
             | What difference does it make who demonstrates it? All that
             | matters is application, performance, and whether it is fit
             | for purpose.
        
               | ch4s3 wrote:
               | I think the earlier posters are pointing out that no one
               | else seems to be able to safely operate the thing, which
               | suggests that it might not be fit for purpose.
        
               | Dylan16807 wrote:
               | The amount of training matters. If it's always him, that
               | has some implications on how hard it is to turn into a
               | product.
               | 
               | And a quick demo doesn't do a good job of showing fit for
               | purpose either. Maybe performance.
        
               | hammyhavoc wrote:
               | I can see this potentially having some usefulness if
               | refined, but from a strictly practical perspective, I
               | can't see many pilots surviving a boarding if the vessel
               | has any firearms. It just lacks maneuverability.
        
               | chrisseaton wrote:
               | You (obviously) combine it with fire support. Just like a
               | ladder or helicopter assault on a ship, or an infantry
               | attack on land, or really any other military manoeuvre.
        
               | hammyhavoc wrote:
               | Sure, I don't disagree here. My point is that whether it
               | is fit for purpose remains to be seen or whether it's a
               | solution in search of a problem versus alternatives.
        
               | toqy wrote:
               | Isn't the point being made that there is nobody else
               | capable of demonstrating it?
        
         | samstave wrote:
         | Question: How impracticable is the following:
         | 
         | ---
         | 
         | you have a machine with micro-thrusters (of whatever fuel-
         | source)
         | 
         | It is driven by modern drone tech for stability.
         | 
         | How driven, super simplistic maths for establishing
         | thrust.telemetry.balance...
         | 
         | How the FUCK has this not been solved?
         | 
         | A belt of jets. They fly you without killing or burning you.
         | 
         | We are significantly evolved for this to happen...
         | 
         | Seriously. This is a solvable thing. Do it.
        
         | jollybean wrote:
         | That's legit R&D.
         | 
         | Marines storming a ship is an obvious use case where the high
         | cost will be accounted for (i.e. we have a lot of expensive
         | gear for specific purpose) and it's a practical scenario. Coast
         | Guard same. And certainly other forces. If we can get the gear
         | to be very easy to use and practical, it could very much enable
         | a kind of acute mobility.
         | 
         | There's little direct use beyond that, however, the development
         | of the technology could yield other things as we learn to make
         | those little jets cheap, efficient and intelligent.
         | 
         | Those systems could absolutely be deoployed onto drones, which
         | opens up a world of use cases.
        
         | xtracto wrote:
         | Exactly, right there in the article theres a highlighted quote
         | mentioning this:
         | 
         | > Now, the flight duration is too short, and the degree of
         | difficulty too great. But this was also the case for the Wright
         | brothers
         | 
         | I think the next step for Jetpacks is to develop automated
         | navigation/stabilization systems. We want a Jetpack for which
         | the normal state is flying at a stable height, then with some
         | kind of 3D joystick we can move steadily up, down, front, back
         | and sideways. I think all of this is currently achievable but
         | too expensive to implement.
         | 
         | Also, the amount of energy required to lift a person is just to
         | high, so until better ways to store energy are developed, the
         | "backpack" form factor for storing energy will not cut it for
         | practical flights.
        
           | outworlder wrote:
           | Better and safer too. We need to not only store incredible
           | amounts of energy, but do it in such a way that's safe to do
           | so next to your chest :)
        
           | BizarroLand wrote:
           | Maybe it's silly, but I want wings on my jetpack that are
           | large enough that I can glide, but also that can sheath
           | themselves into each other.
        
         | autokad wrote:
         | it does feel like we made lots of progress though. as we need
         | less fuel for them, they get easier to use, and safety improves
         | we should start seeing some real use cases
        
         | walrus01 wrote:
         | a widely usable 'jetpack' would actually be more like a ducted-
         | fan coaxial octocopter that you wear, with flight
         | stabilization/onboard flight controller not very dissimilar
         | from a large commerical cinema filming octocopter.
         | 
         | if it relies on the person's skill to fly it and has a 5-10
         | minute max flight time, of course it'll be a niche thing...
        
           | falcolas wrote:
           | Theoretically, if you could add adjustable _mechanical_
           | joints, you could hook up a flight controller to it and fly
           | it. Could you add the necessary joints and motivators and
           | stay inside a reasonable weight? Not so sure.
        
             | walrus01 wrote:
             | with arducopter and common COTS flight controllers people
             | have made monocopters that use servo motor controlled
             | vanes:
             | 
             | https://www.youtube.com/watch?v=2Pu-KDuxUwU
        
         | andi999 wrote:
         | I think with a active control unit safe operation should be
         | possible. There are fighter jets that cannot be flewn manually
         | (unstable flight behaviour). Probably range and use case is the
         | problem.
        
         | ArnoVW wrote:
         | While indeed people do not use jetpack in a day-to-day manner,
         | they are becoming slightly more 'available' than you portray.
         | 
         | See this video where one of the corridor crew members
         | participates in a jetpack training.
         | 
         | https://m.youtube.com/watch?v=-R5xYaqQo4k
         | 
         | I think it's more precise to say that they are currently a toy
         | for the rich.
        
       | JoeAltmaier wrote:
       | " And this is the tragedy of jetpack technology. They can't hold
       | enough fuel for more than eight minutes of flight "
        
       | Borrible wrote:
       | Yes, why don't we care? Inquiring minds need to know!
       | 
       | https://qz.com/1667783/why-doesnt-the-military-have-jetpacks...
        
       | citizenpaul wrote:
       | Jetpacks are only useful if there is no infrastructure. You can
       | get a motorcycle for <$500 that is infinity more useful than a
       | $500,000 jetpack. Hop on the road and get where you want in a
       | moment.
       | 
       | Plus a jetpack requires special licensing and pre approved flight
       | plans, ect.
       | 
       | Jetpacks are only a toy, a very, very expensive toy as they are
       | now.
        
         | hirako2000 wrote:
         | it's rather $300,000, but at the burning rate of several litres
         | of kerosene per minute, your budget isn't far off reality of
         | actually owning one and using it.
        
         | byw wrote:
         | Or even a light helicopter. You can get a Robinson R22 (2-seat)
         | for around $300k new, or R44 (4-seat) for around $500k.
        
         | twobitshifter wrote:
         | A Honda Grom is still $3500, but I don't think that weakens
         | your point about cost. However, similarly to jet packs,
         | autogyros, ultralights, and paramotors, motorcycles are not as
         | popular in the USA, due to safety concerns. So even though
         | motorcycles are very useful and cheap, people don't ride them
         | much. I think the same would be true of a $3500 jet pack.
        
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