[HN Gopher] LTA Research's Pathfinder 1
___________________________________________________________________
LTA Research's Pathfinder 1
Author : mfiguiere
Score : 85 points
Date : 2022-12-11 16:46 UTC (6 hours ago)
(HTM) web link (spectrum.ieee.org)
(TXT) w3m dump (spectrum.ieee.org)
| thenoblesunfish wrote:
| I like it because I think airships are super cool, but I have no
| idea why I feel that way. Seeing as this, unlike some other
| solutions-looking-for-problems these days, is cheap and benign
| enough for some rich guys to tinker with even though it's a
| little whimsical, have fun, y'all and watch out for the
| Rocketeer.
| golemotron wrote:
| The imminent airship revival has been going on at least since the
| 1970s according to Popular Mechanics.
|
| It's an evergreen magazine topic, like six-pack abs on the covers
| of men's fitness magazines.
| Apocryphon wrote:
| Or reusable rockets? Electric cars?
| Waterluvian wrote:
| I keep hearing that helium acquisition is getting trickier and
| trickier. Would these airships meaningfully impact that further?
| Or is it not actually a problem at scale yet?
| photochemsyn wrote:
| That's what I was thinking too. Seems to be an ongoing issue:
|
| (May 2022) "Helium shortage 4.0"
|
| https://qz.com/2171115/the-world-is-facing-helium-shortage-4...
|
| The major uses include for cooling magnetic resonance imaging
| equipment at hospitals, and for weather balloons (critical data
| for short-term weather forecasts). However, small drones may
| take over from weather balloons for data collection soon. Lab
| research and manufacturing processes seem to be in third place.
|
| I suppose if airships can hang onto their helium long-term,
| it'd be less of an expense. Interestingly hydrogen though
| flammable provides more lifting power... maybe hydrogen-filled
| drone airships would be an option for delivering goods, if not
| people.
|
| https://www.airships.net/helium-hydrogen-airships/
| worik wrote:
| >and for weather balloons (critical data for short-term
| weather forecasts
|
| Why not use hydrogen for weather balloons?
| brudgers wrote:
| Reading the article, I got the feeling technology hasn't been the
| limitation, infrastructure has.
|
| It wasn't surprising that the first picture was at Moffit Field.
| There's an airship hanger there you can see from the freeway.
|
| But what fired my neurons is the mention of Akron, because there
| is an airship hanger there because that's where Goodyear was/is
| headquartered. [1]
|
| These are specialized buildings with non-trivial structural
| requirements...when buildings get that big holding them down is
| at least as hard as holding them up.
|
| Not technically, all it takes is concrete. [2] Physically it
| takes a lot of concrete and the more efficient the superstructure
| the more concrete it takes. Cover a skeleton with fabric and you
| have a very very large sail.
|
| This makes staging for humanitarian missions more difficult than
| ordinary alternatives like a C130. A minimum viable airstrip can
| be constructed in days (i.e. weeks), an airship hanger will take
| months (i.e. years).
|
| That's not to say there's no possible niche in humanitarian
| missions. Just that it is no more obvious to me than to the
| article's author (and presumably it was not clearly delineated by
| the company to the author).
|
| But I am being presumptive and recognize I may well have missed
| something.
|
| [1]: Too lazy to research tire industry consolidation.
|
| [2]: and steel to transfer all the uplift and sheer forces to
| that concrete and more steel to distribute those forces --- and
| no, Roman concrete doesn't avoid this...and besides the Tufa
| makes it less dense and therefore would require more volume even
| if unreinforced concrete is brittle and therefore terrible in
| tension and fails catastrophically. But I digress.
| batman-farts wrote:
| Interesting that LIDAR is one of the sensors used to monitor the
| helium cells. One thing that isn't clear: is there any
| appreciable helium loss through their fancy triple-layer skin? Or
| can this just be filled once with helium from the factory and
| then forgotten about for the life of the airship?
| 082349872349872 wrote:
| On the green side, a book I'd read about the Zeppelin world
| circumnavigation said that wayfinding was much closer to sailing
| to take advantage of/avoid the weather than to "pick a geodesic".
| TFA mentions intermediate between air freight and ocean freight;
| I wonder how these airships compare to trucks and trains?
| ttepasse wrote:
| Something these articles never mention is the cargo conundrum:
|
| If one of these cargo airships puts down its heavy cargo in a
| remote location the airships whole mass balance changes - the
| airship is suddenly far lighter because it doesn't contain the
| mass of the cargo anymore. To keep the airship from rising into
| orbit of the mass of the cargo must be replaced (or the expensive
| helium let go). The german Cargolifter startup back in the late
| 90s intended to do this with pumped water and I remember a
| prototype demonstrating that successfully by lifting and lowering
| a tank.
|
| But: To transport your cargo to that remote, inaccessible
| location you'll need to transport the airship ground support to
| that remote, inaccessible location: infrastructure for anchoring,
| a pump, a generator for that pump, fuel, and possible the same
| mass of water as the cargo. And if you can transport all that
| mass by conventional means to that remote, inaccessible location,
| chances are high that you can already transport the cargo to that
| location.
| Loquebantur wrote:
| You could solve this by compressing the helium onboard,
| replacing it with air filling a balloon inside. Of course this
| complicates matters.
|
| Another way would be to ditch gases altogether and go for
| containers able to hold a vacuum against air pressure.
| Something along the lines of an aerogel with an airtight
| membrane around it.
| [deleted]
| jetrink wrote:
| Is it infeasible to compress a portion of the helium to a
| heavier than air density instead of venting it?
| imoverclocked wrote:
| Yes, but once there, it doesn't have to move again.
| [deleted]
| bagels wrote:
| Technology may not be as big a challenging as the businesses
| model.
| kentlyons wrote:
| I wonder about airship based (inland) cruises. The cruise
| industry is on the order of $20b annual and I could imagine a
| similar experience by air, going no where fast, and opening up a
| very unique tourism experience to very different types of places.
| bombcar wrote:
| This is where it will come back if it does.
|
| Since lifting empty space is "free" you can have absolutely
| huge rooms in a cruise ship of the skies.
| alpos wrote:
| Lifting an enclosed space is not free. Gravity is still in
| play so "huge rooms" means more floor space. Floor space is
| surface area and material costs by the square foot or meter
| both in terms of construction costs and in terms of weight.
|
| On top of that, any time you're moving through a fluid your
| speed is determined by your thrust/drag ratio. When adding
| more space internally you have parasitic drag and induced
| drag working against you. Parasitic drag increases as you add
| surface area and when you grow your forward facing profile.
| Induced drag increases with the amount of lift you need to
| fly, more sq.ft, more material weight, more lift needed, more
| induced drag. Airships mostly fly with lifting gas but still
| generate a lot of body lift once they start moving.
|
| So if you'd like to go anywhere once you get off the ground,
| you're going to need to balance cabin size against the size
| of the engines needed to produce enough thrust to travel at a
| reasonable speed along with the fuel weight required to
| travel any distance.
| brudgers wrote:
| While possible, amenities, staff, food, water, and human waste
| are likely to require most of the lift capability.
|
| The cruise industry is constantly retooling for economy of
| scale.
| jeffreyrogers wrote:
| The article doesn't mention weather which seems to be one of the
| biggest reasons these never took off.
| PhasmaFelis wrote:
| Or, sometimes, took off dramatically at inconvenient times and
| velocities.
| devonallie wrote:
| Nice.
| bediger4000 wrote:
| Airships are like fusion and flying cars, always N years in the
| future. Why should we believe it this time?
| Ekaros wrote:
| I think more like they don't really make sense. Not that
| technology isn't ready.
|
| Which is entirely different from fusion. On other hand flying
| cars are combination of both, they don't make sense and
| technology isn't ready.
| ajmurmann wrote:
| Why do flying cars not make sense, assuming the technology
| was perfect? Cars could go more direct routes to their
| destinations and we could give so much ground area that's
| currently dedicated to cars back to pedestrians and other
| modes of transportation.
| Ekaros wrote:
| I just don't believe the math on efficiency. Wheels are
| darn good in efficiency. Wings sure can work in some
| scenarios, but most flying cars I see are some type of
| quadcopter or like which I find questionable. And anti-
| gravity is not happening.
| mrkeen wrote:
| It would take too much energy to keep them off the ground.
| FartyMcFarter wrote:
| The occasional helicopter flying over a city is already
| noisy enough to be annoying. There's no way people would
| put up with hundreds of flying cars above at any given
| moment unless they're much less noisy than that.
| danhor wrote:
| Aside from technical concerns, they're loud as hell during
| takeoff and landings, making their use inside populated
| places a bit controversial.
| febusravenga wrote:
| Energy. Flight control. Congestion. Accidents. Noise. All
| those would be much difficult, worse / problematic or even
| catastrophic when flying vehicles would be accessible to
| literally everyone, including criminals, drunks and
| teenagers.
| Ekaros wrote:
| Also not to forget misuse scenarios. We already blockade
| roads around large events when there is lot of
| pedestrians around. How would we do same for the sky? If
| there was hundreds or thousands of flying cars. Drones
| are one thing, but tonne or multi-tonne vehicles?
| kshacker wrote:
| Technology has been making progress all this time. It may be
| slow progress like FSD or a fast progress like many of the
| things in Moore's law.
|
| We still do not need to believe it, but obstacles do get
| overcome with time, and if at some point someone can make a
| business out of it, we will wonder why it took so long since it
| was so easy.
| alpos wrote:
| None of those things are N years in the future. That's a bad
| meme. We have had fusion that works, flying cars that work, and
| airships that work for 50ish years.
|
| A thermonuclear bomb set off in a giant underground tank of
| water would make a lot of power and we would have no trouble
| controlling and harnessing that. We just don't want to do it
| that way. We already have tons of trouble getting people to
| approve building a controlled nuclear melting pot anywhere near
| them, no one would ever agree to let you detonate bombs under
| their feet. That doesn't mean the tech doesn't work. It means
| we don't want to use it.
|
| And flying cars have existed since the term was invented.
| They're called airplanes. You can get a four seat one to fly
| yourself for about 40k. They are a bit harder to "drive" than
| regular cars and we don't make as many places to park them so
| most people don't want one. Plus gas prices already limit how
| much people drive, try burning 10 gallons/hr.
|
| Airships work too, they just occupy a niche that we do not have
| a need for other than entertainment value. Cargo ships get lots
| of stuff across water cheaper, trucks get stuff across land
| cheaper, and cargo planes get more stuff through the air
| faster.
| PeterHolzwarth wrote:
| These articles have been periodically popping up since the 1990's
| - I seem to notice them on average about once a year.
|
| I assume it happens each time a company has got some funding
| together to start some early prototyping.
| failbuffer wrote:
| Yep, it's a perennial. Naieve entrepreneurs and investors love
| the romance of these vessles, but they will never carry enough
| payload fast enough to compete with the vast array of existing
| options. All they're good for is suckering grant money and
| writing clickbait.
| Apocryphon wrote:
| Heaven forfend research into an area beyond adtech,
| blockchain, or surveillance
| Animats wrote:
| The payload is only four tons. That's only about twice the
| capacity of a Huey, and less than a Super Puma. Both of those are
| widely used utility helicopters.
|
| Fly by wire airships are not new. DARPA had the Lockheed Skunk
| Works develop one. That was nicely maneuverable; it could taxi
| out of a hangar and take off, fly around, then land and taxi back
| home. Fans on multi-axis gimbals for control.[1] Worked fine,
| nobody could find a use for it.
|
| The Zeppelin NT airships (remember Airship Ventures flying over
| Silicon Valley) worked quite well. Not quite as maneuverable as
| the Skunk Works craft, but far easier to dock than traditional
| airships. The guy behind that used to speak at steampunk
| conventions. When the price of helium doubled and the tourist
| business collapsed in 2008, they had to shut down.
|
| The big cost item with these things is replenishing helium
| leakage.
|
| There may be a market for flying yachts.
|
| [1] https://www.dailymotion.com/video/x4cnc6
| clhodapp wrote:
| Four tons but you don't burn fuel like crazy just to stay up.
| prox wrote:
| I think I read these articles for the past decade. Although
| Pathfinder 1 will actually start tests in the beginning of next
| year, so that's pretty good. It's pretty green as a vehicle
| though once build.
| JumpinJack_Cash wrote:
| Would you take a "cruise" through the Grand Canyon aboard the
| gondola of an airship?
| Slighted wrote:
| Hydrogen instead of helium is clearly the elephant in the room.
|
| Helium is expensive, limited, and not easily produced, whereas
| hydrogen is readily available almost anywhere, has no
| quantitative limits, and provides far superior lift than helium.
| Of course, hydrogen is extremely flammable and explosive. If
| there was a way to minimize or completely mitigate this problem
| then airships would certainly become more viable than they
| currently are. The article mentions the use of fire-retardant
| materials as part of its covering. Perhaps this in combination
| with tens of thousands of isolated gas "sacs" and an outer helium
| buffer (To isolate the hydrogen from external heat sources,
| laser-based weapons, static electricity, etc.) could make
| hydrogen a viable choice?
| NickRandom wrote:
| An added advantage of using that approach is that as you drop
| off cargo (or use up food, water and fuel supplies for multi-
| day passenger trips) you can siphon off some of those cells to
| power the propulsion motors and thereby increase your effective
| range.
| TheDudeMan wrote:
| What about the embrittlement? That seems like the deal breaker.
| didericis wrote:
| Is there a possible future in which lowered cost to orbit and
| helium scarcity makes it economically viable to harvest helium
| in giant sacs in space, and then use "gas stations" floating in
| the upper atmosphere at different buoyancies to shuttle it down
| to airships?
|
| I have no idea how many problems there are with that, or how
| diffuse helium is/how hard it would be to harvest from space,
| but floating airship stations like Bespin would be _awesome_.
| herendin wrote:
| Helium's so scarce. You're attempting to reduce ultra high
| vacuum to even less. Not practical
| brudgers wrote:
| To a first approximation, space is a vacuum.
|
| Most of the second approximation is hydrogen not helium.
|
| Yes proportionally, there's a fair bit of helium but most of
| what's there is nothing.
| didericis wrote:
| Is that true of the upper atmosphere? Wouldn't it clump
| there due to gravity?
|
| And if it doesn't clump there, does it clump anywhere, or
| is there some reason it's naturally diffuse?
| cjbgkagh wrote:
| Solar wind blows it away.
| alpos wrote:
| The bigger problem with hydrogen is making a container it
| doesn't escape so much faster than Helium as to negate the
| extra lift advantage.
|
| You can let it leak out, but then you need to carry extra
| compressed gas above what is already needed for the same issue
| with helium.
|
| You can build a tighter, multi-layered envelope, but then
| you're adding weight and quickly negate the extra lift. This is
| the category your tens of thousands of sacs idea falls in. The
| problem there is that you are massively increasing the surface
| area through which the hydrogen can slip out. You have to keep
| in mind, to a single hydrogen atom, everything we consider
| "solid" looks more like a fishing net for catching a whale. Our
| best designs so far usually involve layering and offsetting
| those nets so as to at least slow the atoms down as they path
| through the mesh.
| politician wrote:
| I wonder how strong a magnetic field would be need to be to
| prevent leakage in an airship using ionized hydrogen as a
| lifting gas.
|
| Assuming that the airship can sustain a 10K C hydrogen
| plasma, of course.
|
| Maybe just at the boundary.
| ngvrnd wrote:
| So... you want to replace flammable hydrogen with...
| ionized hydrogen. Hm.
| alpos wrote:
| I've thought about that one off and on for a while too.
| Maybe something like an thin wire electromagnetic mesh as
| the inner layer of the envelope but I'm guessing no one has
| tried that at scale because the math says no.
|
| Most likely you either have to pump a lot of power through
| the mesh to get field coverage enough to reliably bounce
| atoms away from the skin or you have to make the wire mesh
| so dense that you've basically got a layer of copper as
| your envelope and are therefore far too heavy to lift off.
|
| It seems like too obvious an option to have simply been
| missed over the decades.
|
| Still, I have to wonder if someone will invent a way to
| coat a string of fabric in like 1nm thick copper film. Or
| maybe graphene will save this idea too.
| sandworm101 wrote:
| The realworld differences are slighter than many think, on the
| order of 20% more lift. The mass of the h/he isn't a
| significant factor compared to that of the displaced air. And
| hydrogen is harder to contain, which further limits available
| lift.
|
| Another less-discussed option is hot air/helium combos, which
| at large sizes have some distinct advantages.
| bombcar wrote:
| 20% is huge and you don't really worry about containment if
| you're setup to just replace the hydrogen as it escapes.
| sandworm101 wrote:
| A leaky bag of hydrogen in bad weather. What could possibly
| go wrong?
| alpos wrote:
| If you're set up to replace the hydrogen as it escapes then
| your lifting gas is a fuel you have to buy for every flight
| in addition to the fuel for your engines and now you're
| paying an energy tax to haul fuel and lifting gas in
| addition to cargo. This makes the entire setup an even
| worse competitor against planes, trucks, and ships.
|
| Many of the ideas we all come up with for airships
| technically will work and the fact that we keep thinking of
| these things over and over again through the years speaks
| to how fascinating the concept of an airship is; however,
| we've never had a problem making an airship that works.
| That's the easy part. Making one that anyone would want to
| use for everyday transport is the hard problem.
| Aaargh20318 wrote:
| Since the only real point of h/he is to replace air, what
| about using neither ? Has anyone ever attempted to build a
| vacuum airship ?
| Loquebantur wrote:
| http://cba.mit.edu/docs/papers/19.01.vacuum.pdf
|
| https://www.esa.int/ESA_Multimedia/Images/2021/11/Vacuum_ai
| r...
|
| https://www.nasa.gov/directorates/spacetech/niac/2017_Phase
| _...
| nateburke wrote:
| They buried the helium bit! I really had to dig for
| confirmation that they weren't going to give hydrogen another
| go, what with the constant comparisons to Hindenburg
| throughout.
| [deleted]
| orangeplus wrote:
| It's a rocket jetpack for your self-driving flying car powered by
| blockchain!
| RcouF1uZ4gsC wrote:
| > LTA expects Pathfinder 1 to carry approximately 4 tonnes of
| cargo, in addition to its crew, water ballast, and fuel. The
| airship will have a top speed of 65 knots, or about 120
| kilometers per hour--on par with the Hindenburg--with a sustained
| cruise speed of 35 to 40 knots (65 to 75 km/h).
|
| This is the big problem with airships. Over land, they are
| competing with large trucks which can carry 25 tons of cargo at
| similar speeds. Over water, they are competing with cargo ships
| that can carry 1000's of times that amount of cargo, again with
| roughly similar speeds.
| subradios wrote:
| Well, sort of - fuel costs are real. Being able to transport 5
| to 10 tonne point to point (you do not need an airfield to land
| an airship) while using very little or no fuel that produces
| another avenue of competition.
|
| Cargo ships also run at a third of the speed, their advantage
| is fuel efficiency by weight and number of human crew by
| weight.
|
| If you could get capacity to something like 10 or 25 ton, it
| could directly compete with cargo by being slightly faster and
| more fuel/manpower efficient
| deafpolygon wrote:
| But what they can do is carry cargo over terrain that is
| unsuitable for both.
| foobarbecue wrote:
| Yes, in theory. I remember when Lockheed took over the US
| Antarctic program support contract and claimed they would use
| an airship to transport stuff to S Pole. It was obviously
| ridiculous given the weather. If it weren't for that it might
| make sense.
| 082349872349872 wrote:
| Said terrain is almost by definition not on established trade
| routes.
|
| But maybe Russia will want to massively increase their
| southeastern trade?
| jaclaz wrote:
| Yes, I remember some 20 years ago there were projects for
| even larger airships (please read as carrying bigger loads)
| aimed at supplies to otherwise inaccessible
| places/construction sites/mines, called Cargolifter:
|
| https://en.wikipedia.org/wiki/Airship#Heavy_lifting
|
| https://en.wikipedia.org/wiki/CargoLifter
| alpos wrote:
| Still not seeing anything that addresses the counter-points made
| here the last time the tech was supposedly good enough to win:
|
| https://blogs.scientificamerican.com/guest-blog/helium-hokum...
|
| Airships occupy an unfortunate gap in the cross-section of mass
| moved over distance per time and energy space. Unless they build
| one that goes faster than a plane for the same fuel or consumes
| less fuel to get the same amount of cargo across the same
| distance, it will always be better time/money spent to clear a
| dirt runway or build a road.
|
| New materials don't get us there. At best, the new envelope saves
| on how much helium needs to be bought in addition to fuel...but
| that's competing against other tech that doesn't need to buy
| helium at all.
|
| And going all electric doesn't do it either. That only forces the
| trade off between cargo capacity and energy generation/storage.
| We already know batteries are not more energy dense than jet fuel
| so that will continue to be a losing trade until batteries equal
| chemical fuels. This is made even worse by the fact that fuel
| burns off in flight, making fueled engines more efficient during
| the flight while batteries are just as heavy empty as they are
| full.
| xphos wrote:
| I think less fuel is exactly what the goal is and not to
| mention types of fuel if you could move 100 tons across the
| Pacific ocean on electric turbines powered by solar you'd
| certainly could amortization the speed of delivery by just
| scaling the pipeline with more airship.
|
| The unknown is the lifting gas helium is expensive and hydrogen
| can leak and go boom. But the speed does not necessarily matter
| if the cost is much lower and sustainable
| brudgers wrote:
| A 100 tons across the Pacific suggests a ship.
|
| Or the 747-8f if you are in a hurry.
|
| https://en.m.wikipedia.org/wiki/Boeing_747-8#747-8_Freighter
| alpos wrote:
| Thing is you're never going to beat the lift/drag ratio of a
| cargo ship doing that. Cargo ships already play the slow but
| chonky game. The only limits to their size is space at the
| ports and the number containers that can be loaded/off-loaded
| per day.
|
| Technically you could build an airship that only uses power
| to get into a jet stream then floats across the Atlantic on
| the wind saving tons of fuel, but then you've reinvented a
| sailboat in the sky and the buoyant force of water always
| beats that of air. So you might as well put your cargo in an
| actual sailboat and get there faster (see ocean currents v
| wind above them) without needing to "fuel" the thing with
| hydrogen or helium.
|
| This is just one example of the cross-section we can't
| escape. It is as tyrannical as the rocket equation is to
| space travel. For anything to be a viable transport, it needs
| to go faster, use less fuel, or carry more cargo than other
| modes of transport.
| oefrha wrote:
| > The company sees a natural fit for airships in humanitarian and
| relief missions.
|
| Doesn't sound like a big market, and it has to compete with cargo
| planes (faster, more capacity than this Pathfinder 1 with only 4
| tons) and helicopters (more nimble).
| simplotek wrote:
| > Doesn't sound like a big market, and it has to compete with
| cargo planes (faster, more capacity than this Pathfinder 1 with
| only 4 tons) and helicopters (more nimble).
|
| Some companies manage to be successful by tapping a market
| whose demand comes up rarely but is highly inelastic. We're
| talking about stuff like sea lifters that can handle ocean
| liners, or even mobile power stations.
|
| I'm sure that some deep-pocketed organizations whose know-how
| focuses on subcontracting and commissioning work, like the UN,
| would willingly pay a premium to be able to transport large
| volumes of cargo throughout regions with little to no
| transportation infrastructure and where roadway traffic is a
| major volnerability. Being able to secure logistics without
| having to control routes or have to police anyone would be
| worth a small fortune.
| imoverclocked wrote:
| I would love to see a vacuum based airship! Stop filling the void
| with anything and recoup the some of the added structural weight
| by (nearly) complete absence of mass. Then the game is just
| keeping all gasses out instead of keeping a special gas in.
| Implosion hazards would be interesting to mitigate though...
| xphos wrote:
| It's really really hard to pull a vacuum on a large area the
| internal stress of not having a fluid is way way more than a
| less dense fluid occupying the space
| imoverclocked wrote:
| Yeah, but exotic materials like graphene aerogel might allow
| for static pockets to fill the void. We (humanity) have
| developed some pretty insane materials since we really
| explored the airship space originally. It would at least be
| interesting to explore.
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