Cargo airships could be big | Hacker News Reader

Cargo airships could be big

elidourado.com

389 pointsLuc374 comments

The airship renaissance is the fusion of transportation world. It's always ten years away. Seriously, I've been hearing about the great promise of modern airships for twenty years. Where are they? Are there any airships operating commercially now outside of niche applications?

Direct weather control is the prerequisite technology for at scale operation of commercially viable airships. So once we crack that I'm sure we will see them!

We have very good weather prediction these days. After the Titanic sank and people argued about mandating lifeboats on ships, one of the arguments against was that global shipping had already settled into the least stormy most safe sea routes and accidents where lifeboats might help had reduced year on year because it was already in everyone's interests - cargo sellers, shipping industry, passengers, insurance industry - to make that happen.

We have very good weather prediction for tomorrow. For longer airship trips like spending a few days crossing the Pacific Ocean the exact tracks of storms are harder to predict, and dangerous squalls can brew up with little notice during certain seasons.

Of course it's niche applications, but it is the Zeppelin NTs which is the biggest success story. They're used for tourism in Germany and advertising in the US (the Goodyear Blimps, which as the article points out are no longer blimps at all, but much larger Zeppelins).

Zeppelin Luftschiffstechnik have survived by being _very_ careful about the scale of their ambitions (i.e, it's very modest). They did deliver the three ships in the Goodyear fleet, though, as far as I know completely on schedule, which is rare in any project of that scale, let alone an airship project.

I still haven't written off Sergey Brin's project entirely, although it keeps getting delayed. Airlander I'm less optimistic about, but they did fly (and crash) their prototype and they're still around, so who knows.

The Sergey Brin airship project is Lighter Than Air (LTA), in case any one was wondering.

https://www.ft.com/content/ae625a25-d2ac-4bca-9508-a5f0d3c7d...

How much do you want to bet the employees working on this were apart of the anointed 12k that just got laid off

LTA is not google/alphabet affiliated

I wonder why, why was this not, and Loon was?

Brin is toxic to the Alphabet brand. Too much using the staff as a sexual smorgasbord.

Given that i cannot find anything to suggest it is a subsidiary, I would stake a healthy sum that they did not particiapte in the Google layoffs

one does not lay of the team of a pet project of the confounder/board member with controlling interest in your company lightly.

Pet projects often get replaced with new pet projects...

If US, China and Taiwan situation escalates and US imposes a naval blockade, this can be used to effectively circumvent it. Perhaps China should invest in this.

Massive airships flying 90/km an hours are LESS susceptible to blockades than cargo ships? I think I'll need a little more explanation than that. Seems like a shoulder-mounted rocket launcher would be more than enough to bring one down.

Or a single tracer bullet, if it's filled with hydrogen.

Surely you could design some redundancy into the hull? It's not like the ship needs to be one giant gas bubble. It can be a mesh of a few hundred bubbles that could each pop without bringing the whole thing down.

So… 100 tracer bullets instead?

So several hundred times the weight of the pressure envelope? Tracer bullets was only an example. Airships would be spectacularly vulnerable to all sorts of modes of attack.

Surely you could design your tracer bullet launcher around repeatable processes, so that you could send a few more shortly after?

Don't even need to pop all the bubbles. Just enough for lift < weight. Gravity automates the rest.

Apparently that's not actually the case. The Brits and French had a hell of a time shooting down German Zeppelins in WWI with standard tracer ammo.

Standard tracer ammo, yes. As was the case with most weapon systems in WWI, innovation ran rampant and the various armed forces tried out any number of solutions such as explosive-filled bullets[1]

[1]https://en.wikipedia.org/wiki/Pomeroy_bullet

Airships were routinely used and shot at in WWI, but very few were lost due to being hit.

If you think about it, it makes sense: they are massive, so the loss of pressure from a bullet hole isn't a real concern. And while the right hydrogen-oxygen mix is explosive, hydrogen needs oxygen to even burn. But there isn't any oxygen in the tank bladder. The escaping hydrogen can burn as it mixes with air if it finds an ignition source, but as long as your hull is from fire resistant material the flame can't do much, and is probably extinguished by the next wind gust.

Of course the "make your hull from fire resistant material" is where the Hindenburg went wrong. Her hull material could have been used at rocket fuel, the engineers just didn't realize that.

A quick scan of the Zeppelin list on wikipedia shows that significant proportion were lost after being hit by enemy fire. For example: LZ 20, 21, 22, 23, 28, 29, 32, 33, 34...

China has been investing in (non-sea) logistics routes for over a decade. It's called the Belt and Road Initiative (BRI).

To be clear, developing sea routes is also an aspect of it.

Now you've got me wondering if composite frame airships could be made transparent to radar.

Imposing a blockade is an act of war, in the unlikely (and horrifying!) event that it came to that, they’d probably be better served with overland shipping. Also airships would seem to be a pretty bad pick against America, we’re primarily an air superpower.

Not to mention the whole mutual massive nuclear strikes thing, so who would NATO or China be trading with in any case? Waiting for aid from Indonesia or Brazil would be a more likely outcome.

But hey, on the up side, at least no one would have to worry about a blockade!

I know some of the Canadian provincial governments were looking at using airships to provide a means of supplying some of the more remote northern towns - because of weather/terrain conditions, you can't build a rail head that far north, and the roads aren't reliable, so light cargo planes are the only reliable means of getting goods around. Airships, even of the good year variety, would be far cheaper for the weight/volume transported, but initial costs were prohibitive, if I recall correctly

How do airships fare in bad weather?

Not very well. [0]

[0]: https://en.wikipedia.org/wiki/USS_Akron

An extreme example. One extraordinary event is not very good evidence.

The safety record of the Zepplin company in Germany is very impressive

They had many failures, no fatalities. Until the Hindenburg

The USS Akron, USS Shenandoah, and USS Macon all failed due to bad weather. That's 3 of the US's 4 operational airships. (Another airship was constructed for the US, but was destroyed by poor handling before it was delivered to the US.)

Of the British experience with airships, R101 outright failed due to bad weather, and three more were scrapped after suffering accidents during bad weather, out of a total of 16 completed.

I don't feel like totting up the record of the Zeppelins, but the Wikipedia page does indicate that several of them failed due to weather incidents. One of the big lessons from the most notable airship failures is that airships don't really work in poor weather, and safety in such conditions means "don't even attempt to fly," which is a pretty different rule than the one for airplanes or other modes of transportation.

I mean if the alternative transports also don't work in bad weather I'm not sure you can use some failures to disqualify airships.

So long as they work "more" days of the year it's a better solution. Weather doesn't really sneak up on us anymore.

Aircraft are substantially more resistant to bad weather: you can fly an airplane into a hurricane.

Aircraft are also a lot faster -- it's unlikely that a thunderstorm will catch up with you (max speed of a storm is something like 50-80 mph) and trips are a lot shorter.

Airships are much closer to the storm speed and may need to stay aloft for several days. That makes it more likely that they'll hit unexpected weather and give them fewer options to avoid anything.

It's true that someone could do some shipping with airships and just eat the downtime due to weather. So far nobody has done that. And not for lack of trying: CargoLifter (mentioned elsewhere in this thread) went bankrupt on this idea.

Airships aren't aircraft?

Its not unexpected that a california resident, one accustomed to fairly temperate weather, would invest heavily into airships.

> I mean if the alternative transports also don't work in bad weather

But they do.

Imagine the kind of storm that can stop a freight train. Or the kind that would give the captain of a large container ship pause.

Now imagine airships facing the same storm.

This thread started because somebody was talking about towns where the weather prohibited rails from being built [1].

Let me know what freight train can run without rails ... All I have to find is 1 day the airship can travel and its better than your trail.

[1]: https://news.ycombinator.com/item?id=34579915

R101 failed because it was a dreadful design.

They are more wind sensitive then car, train, plain, etc.

AFIK in combination with modern drone tech they are less wind sensitive then in the past making them much more viable for many but not all areas.

They could be snow sensitive in the sense that a unlucky combination of wind/weather change and stronger snow could make snow stack on them somewhat, especially on larger ones. But we are speaking about blizzard like snowing here, so not really a problem.

It should be possible to make them operable even under very cold weather, but additional care must be taken to make sure the used materials do not get brittle due to the cold or electronics/mechanics stop working.

So technically it likely is reasonable viable for the Canada case.

The question is if it's good enough above other solutions and not to pricey to the right kind of airships, especially given that they are not mass produced.

Being wind sensitive isn't that bad if you can ride the jet stream for better economics. I see google has a patent for adding sails to airships.

To that end, being able to go to a higher altitude makes things more uniform, doesn't it? I guess I'm not a pilot so I don't know what altitudes make things easier, I know they can't do airliner service ceilings, but can they do 5000 ft? Probably depends on the buoyancy.

While air unmanned ballons are operating higher any airship I'm aware of had much _lower_ altitude limits then many aircrafts as far as I remember. But I don't know weather it where piratical or technical limitations.

And it it's sensitive to wind you probably don't want to get it anywhere near to either of the jetstreams (which in some areas are rather turbulent as far as I remember).

The google patent probably is from when they operatted unmanned balloon and drone mounted radio stations for special purpose usage. I think they stopped it even through it worked okayish because it wasn't profitable enough but I don't remember for sure.

You wrote:

    you can't build a rail head that far north

The Trans-Siberian Rail can do it... but Canada cannot?

It's not really under consideration to build a railway to Attawapiskat or other remote areas. It's a question of cost mostly.

Railways (I imagine especially in permafrost) require a lot more maintenance than a basic airstrip

Beside the point, I know, but the Trans-Siberian goes through southern Siberia.

Virtually all of the Trans-Siberian railroad (except for the Amur-Yakutsk spur) is below the Canadian North. There are railways to northern places in Russia (such as Murmansk), but Murmansk has 200k people (down from 500k in 1989), where the largest settlement in the Canadian North is Yellowknife, with 10% that number.

So it's not that you _can't_, but it's a PITA, and it's very far from value for money for so few people.

Russia is also hard up for ports, hence Murmansk, whereas Canada has always had Halifax.

> because of weather/terrain conditions, you can't build a rail head that far north

Can't or it costs too much for the benefit? Norway (with extreme weather and horrible terrain) has an extensive rail network, including in the Arctic, so i doubt there's anything in Canada making railways impossible. Too expensive to service 0.02 people per km2 maybe.

No, the airship renaissance was over a decade ago. Cargolifter tried, and failed. From what I heard so, the water and holiday park they built in the ex Cargolifter hangars has to be quite good so.

Are you talking about Tropical Islands Resort outside Berlin, Germany?

Ref: https://en.wikipedia.org/wiki/Tropical_Islands_Resort

They mostly had trouble with landings and takeoffs. Cargo ships could have specialized cranes load and unload cargo while airborne.

That would be very tricky with conventional airships (and even trickier with hybrid ones). You would need to keep the system rougly at the density of air as you are tensioning the crane hoists. Probably by shedding ballast at the same rate you are appying tension on the lifting ropes. While the ship is blown about. And any cable failure would result in the airship violently jolting into the sky.

With hybrid airship this is even trickier, since they relly on airspeed to generate some portion of their full lift.

Could they use a circular lift that loads ballast at the same rate as they unload cargo, the way usually proposed for a space elevator? That would at least solve the ballast problem and lift problem (while still needing a solution to keep the airship in place horizontally AND needing tough materials for the lift).

Or one could stick with the existing transport solutions: sea, air, rivers, truck and rail. Those work just fine to get basically everything anywhere on the planet.

One thing they struggled with was ballast. If you plan on carrying 100+ metric tons, what do you do once you're done? Suck up the nearest lake maybe and dump it back at base when you load your next cargo? Now this restricts your use cases. Not that many lakes people wanna part with in Africa...

Can't you compress the helium and let in some normal air?

Yes: https://en.wikipedia.org/wiki/Ballonet

100 metric tons of water isn't very much water. A medium sized swimming pool will have way more than 100 metric tons of water.

The project I am pitching currently, which has a good chunk of financing secured, envisages passenger operations in seven years.

The piece is almost spooky in its similarity to the piece I circulated to investors a month ago.

We aren’t, however, going after the cargo market.

Will it get off the ground? Who knows. But if you see kilometre-scale airships emerging from the backwaters of Europe where subsidies abound and land is cheap and regulations are… interpretable, you read about it here first.

Hey, do you have some way to contact yourself? I'm from a "backwater" of Europe myself and would love to hear more about your project.

They are waiting for Diamond foil encased vacuum, thats kept apart by statically charged graphene strands. The ultimate in air-buyoncy.

But diamond foil is brittle, and if it cracked, all of your vacuum would leak out.

This, my friends, is why we should colonize the upper atmosphere of Venus, where you could chill outside with only a respirator, rather than the inhospitable, irradiated, mangnetosphere free mars.

https://en.wikipedia.org/wiki/High_Altitude_Venus_Operationa... https://spectrum.ieee.org/nasa-study-proposes-airships-cloud...

A respirator and a teflon suit to keep the sulfuric acid clouds away from your skin?

sure teflon might not be the most comfortable, but think of the speed we could get on a slip n' slide

And what are we going to do there? Mine sulphuric acid from the clouds?

Enjoy the view obviously. Cruise!

In case that wasn't sarcarsm - you won't see much, as you would be inside the acid clouds.

what are we going to do from mars

Everywhere but Earth is really inhospitable, but if it were up to me, I'd pick the Moon first, then Mars, then some asteroids, then way down the list — after we've got space industry sufficient to make planet-sized mirrors — then I'd pick the planet where the surface-level condensation is lead vapour in an acid pressure cooker.

Okay, asteroids presumably make economic sense due to mining potential, but otherwise - why the hate for Venus? What's so special about being on the surface of a planet? Just don't go to where the lead vapour is, enjoy the cloudy view from 50km above the surface instead.

Might be a monkey brain, but the mere possibility of falling 50km through crushing boiling acid is the kind of thing that'll stop me getting to sleep. More so than a deadly vacuum on the other side of a wall.

Yeah but iirc because of atmospheric density it's not crazy to build a floating habitat. At least no crazier then the tech required to get a crew and equipment to Venus in the first place

If your habitat somehow fails on Mars, you have just as much chance of living. Mars' surface is much less hospitable than Venus at 50 km.

The one big thing that Venus has, and every other option does not - is earthlike gravity. That is a big deal, so I am all for exploring options of terraforming Venus to remove that acid somehow, because despite as Space enthusiastic as I am - living inside hot acid clouds is also not my dream.

The thing is about a space economy IMO:

1) getting enough stuff out of Earth's gravity well

2) getting a reasonably self-sufficient population for survival and manufacturing of survival goods

But once you get there, the lack of a big gravity well makes this a lot easier. Low-G or zero-G is a lot easier to move stuff around at the small scales. How much could I lift on the moon?

I'm torn between a moon base and doing enough near-earth asteroid captures to build a space hab. Political support would probably be behind the moon base first, but a space hab built from captured asteroids might be cheaper.

Anyway, once you get a big enough base in space and some manufacturing, build a couple orion pulse nuclear ships, or some nuclear thermal equivalent to hop around the solar system quickly. Then we can probably start mining high value asteroids.

Then Mars and Venus start making sense.

Maybe we can find a closer brown dwarf than Proxima.

THEN, we can go for some nearby stars.

Tourism, mining high value minerals for Earth, mining low value minerals for construction on Mars, manufacturing rocket fuel so that Mars can be the gas station for ships headed for the asteroid belt (enabling more high value mineral mining), low-gravity retirement communities for people with mobility issues who would be wheelchair-bound on Earth, real estate speculation, movies, sports, manufacturing space infrastructure (easier to launch things into orbit due to lower gravity), and basic science.

If I were living on Mars, I would absolutely not be willing to let the rare minerals get sent up into space then down to Earth. Learn to recycle, damn lazy Earthers.

I think you'd appreciate the complex manufactured items and goods requiring plastics that only Earth can export to you. If tons of mined materials or produced goods thereof were the cost, you would be keen to pay it.

Quick research shows that Martian atmosphere is 95% CO2. So if you had a fission / fusion reactor, one use of energy might be to extract carbon from the air. That would also generate oxygen btw.

I mean, sure, how can you expect to live a normal middle-class lifestyle without a few hundred tons of ytterbium? What are they going to want next? Lanthanum? Terbium? Praseodymium? Dysprosium? What else are we supposed to build our palaces out of, plain old ordinary gold? How impractical and gaudy would that be?

If we can get enough minerals from space then we can stop mining on earth which is a horrible process that has horrible effects on the environment. make earth a park nature/nature reserve and move all the industrial base to space where toxins wont poison the rivers, and industrial waste wont kill the animals

Build a second basket for our eggs. There are obviously better baskets than Venus though. I'd sooner choose an orbital habitat.

its not one or the the other though it is very possible to do all of them. build floating Venusian bubble cities, make O'Neill cylinders orbiting around every celestial body of note, while building tunnel cities on mars and the moon and hallow out asteroid and build Stanford Torus in them . We are planet of over 7 billion people we can do more than one thing, and the more varied and distant the baskets humanity is spread to the better.

There is no second basket possible and the idea that there is one is a recipe for disaster

And NOT doing it is a good idea? Like the world governing fuckheads have their heads out of their asses yet after 30 years of the IPCC being validated?

Like we keep being told that population will level out, but I've seen, what, HOLY CRAP, 4 billion people added since I was born, 3.7 --> 7.7.

Because we are totally on top of species depletion? And the world government totally is stable with China and Russia and the US and EU and North Korea and Islam-land and everyone trying to get nukes?

You know what is mind blowingly dumb? Wasting a trillion dollars a year on defense spending, in the US alone.

With China starting to get greedy over space, I think we'll see plenty of investment soon.

Tie things to string and dip them into the acid clouds. Upload the results to youtube for profit.

Yes, for the deuterium, which is enriched by two orders of magnitude over the value here on Earth.

Venus also does not have a magnetic field:

https://astrobiology.nasa.gov/news/in-search-of-an-ancient-g...

So baseline humans would still want radiation protection.

It does have plenty of atmosphere, so radiation isn't a problem. (The problem is everything else, as usually is the case on space.)

Venus has plenty of atmosphere above the surface, but not above the point where there is 1 ATM of pressure.

In case of Earth most of protection comes from our magnetic field. The reason is that magnetic field sweeps ALL charged particles coming from the sun while atmosphere only stops some.

When a particle drops into atmosphere it has a chance to collide with an air molecule, the deeper the higher the chance. But there is always some number of particles that were fortunate enough to reach far enough. Whereas magnetic field is constantly acting on every charged particle and deflects every single one of them.

Only very highly energetic particles can cross magnetic field and these tend to come from outside our solar system and are very low in numbers.

One thing we rely on atmosphere to take care is UV radiation which is photons which is not charged which means our magnetic field does nothing to it. Up to some energies UV is easily caught even by very thing protective layers (for example sunscreen!). It is not like you are going to be showing skin on Venus anyway -- you are going to be always enclosed with material that can stop UV, so this is not an issue. Over certain energies we land in X-ray territory and here our solutions are pretty limited but I do not see a reason why Venerian atmosphere at 1atm should be any more transparent to X-ray than ours.

It has about as much atmosphere above the point where the pressure is 1ATM as we have on Earth. And no, we don't know if Earth's magnetosphere ever filters most of the incoming radiation (we don't such good measurement of the incoming radiation), what we know is that at sea-level, our atmosphere alone is enough.

AFAIK, every time we measure it better, the effectiveness of our magnetosphere decreases. But it can only stop charged particles anyway, and air is very good at stopping those.

There is also probably a range of viable pressures so going down to multiple ATM would still work and provide more shielding.

>And no, we don't know if Earth's magnetosphere ever filters most of the incoming radiation (we don't [have] such good measurement of the incoming radiation)

Where did you hear that?

The space station (and presumably other satellites) is perfectly capable of measuring this.

https://www.jpl.nasa.gov/images/pia04258-comparison-of-marti...

https://ntrs.nasa.gov/api/citations/20070018244/downloads/20...

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/2016...

The space station is in low Earth orbit, so quite low inside the earth’s magnetic field. That’s why the radiation flux shown in the first chart you linked is so low relative to Mars, even though the earth is much closer to the sun. However we have sent out multiple probes able to measure the radiation environment away from earth. There’s lots more to learn, but we already know a fair bit.

1 ATM of air is the same amount of material as 33 feet of water which provides a great deal of protection from charged particles. I doubt enough charged particles can penetrate to the surface that it’s a meaningful issue.

I’ve seen many books etc suggest the earths magnetic field is required, but I haven’t found direct evidence for it doing anything beyond protecting the ozone layer.

>1 ATM of air is the same amount of material as 33 feet of water which provides a great deal of protection

"Amount of material" isn't what's relevant. It's closer to "number of atomic nuclei."

A certain mass of air is less shielding then the same mass of water. By number density, air is mostly nitrogen atoms, whereas water is mostly hydrogen atoms. Overall this means that per kilogram, water contains 2.4x as many atomic nuclei as air.

Of course there are bigger problems with Venus cloud cities. At the 50 km height where the pressure is 1 atmosphere, the temperature is 75 °C (167 °F). At the 55 km altitude where the temperature is 27 °C (81 °F), the pressure is 0.5 atmospheres.[0]

As a bonus, both these altitudes lie deep within the layer of sulfuric acid clouds (50-80 km).

[0] https://en.wikipedia.org/wiki/Atmosphere_of_Venus

Don’t stop there. Charged particles in the solar wind is mostly alpha and Beta particles. 33feet / 2.5 should stop what 99.9999% ish of them?

https://sciencedemonstrations.fas.harvard.edu/presentations/...

Absorbing materials and their alpha particle penetration depths.

5.5 MeV alphas: AIR(STP) 3.7 cm

2.3 MeV Beta: air 8.8 m

Solar wind is even less energetic.

Edit: “Auroral emissions typically occur at altitudes of about 100 km (60 miles); however, they may occur anywhere between 80 and 250 km (about 50 to 155 miles) above Earth's surface.” it really doesn’t take much atmosphere to stop it.

That's not really relevant.

Charged particles from the Sun (SEPs) aren't what determine the design envelope for radiation shielding. Your overall dose will almost entirely come from galactic cosmic radiation (GCR) at much higher energy levels, which is significantly harder to shield against.

Those particles are what ultimately determine your shielding thickness requirements. That's true whether you're on Venus, or Mars, or a space colony.

https://ntrs.nasa.gov/api/citations/20205008318/downloads/20...

NASA’s direct comparisons between New Mexico (55) and Antarctica (160) only showing a relatively modest decrease from earths magnetic field when measured by high altitude balloons, but again very little GCR reaches the surface.

To be clear a very small fraction of GCR is extreme high energy particles which penetrate just fine.

Hard to say, since that's in grays instead of sieverts. The two can give very different curves.

>again very little GCR reaches the surface

On Venus there would be less shielding than on the surface of the Earth.

The minimum acceptable altitude is ultimately limited by temperature, not pressure or radiation.

0.5 atmospheres isn’t a problem: that’s about what Everest Base Camp is. The sulphuric acid might be a bit unpleasant though.

The mass of atmosphere above Venus' one-bar pressure line is significant—it's similar to the atmosphere mass above sea level on Earth.

Also, our atmosphere is much more important for protecting us from energetic particles than Earth's magnetic field. The atmosphere can stop everything the magnetic field can, and more.

Magnetic fields will only protect you from charged particle radiation anyway. EM radiation is a whole different story and needs a special atmospheric composition for e.g. hard UV to be filtered. Venus does have a small ozone layer, but it's 100 times less dense than earth's. So you'd get sunburn immediately if you walk outside without a full body protective suit.

TFA said the planet has a solar wind induced magnetosphere, as well as is partially protected by the Sun from cosmic rays.

Doesn't Venus have sulfuric acid clouds? Would that happen above those?

It is much easier to construct a suit that will protect from sulfuric acid than one that will protect you from low pressure.

The problem with pressure suits is that positive pressure prevents the suit from being flexible, requires it to be made from durable materials, makes doing anything very hard and if there is any puncture you will loose the pressure immediately.

Sulfuric acid can be kept away with a tiny layer that covers your entire body. Also, you will not die (immediately) if you get a small puncture. Very minimal positive pressure is enough to keep vapours outside of your suit even in case of pretty large tear, giving you plenty of time to fix it.

I've always felt people with these ideas are doing pie in the sky thinking and missing the other trends that would beat this concept out.

Humans aren't suited for these environments. We evolved to fit this planet. These gasses, radiation levels, terrestrial foods, etc.

The economics of going to Mars, Venus, etc. are iffy, and humans probably won't enjoy being there. It's McMurdo times about 1000. Getting back is hard.

It's probably another hundred years before this is plausible with our technology and willpower.

You know what will do great in these environments? Robots that don't have biological weakness. That don't need cellular respiration or biochemical inputs.

We'll probably have gotten really far with robotics and AGI in those same 100 years.

Basically, space will be inherited by our successors. Artificial intelligences. Humans just aren't fit for these environments. Robots and AIs are perfectly adaptable, though.

Sci-fi sold us a fanciful picture of humans in space, because that's a fiction that is pertinent to our experience and is relatable. That isn't guaranteed.

If we go anywhere it will be spun-up asteroids. O'Neill cylinders make more sense for a living platform than even earth does. Once we actually have orbital infrastructure, Planets are a horribly unsafe high-cost-of-travel backwater to live on.

I played a very interesting scifi game that solved the “how do humans travel millions of light years” problem with “well, they’re actually clones produced at the destination planet.” I’d list the title but it is a pretty major spoiler.

Sounds very interesting, could you share the title anyway?

I once had an idea to write a collection of scifi stories with this premise, where every "seed" pod reaches a different planet and each society of clones evolves differently, providing a bunch of different stories related by a "framing" story.

I think it’s Mighty Kaiju Deimos.

That is a name of a piece of media in the game.

It's 13 Sentinels Aegis Rim. It is like 90% visual novel and 10% RTS.

You need to keep taking your medicine if you want to get better, Juro.

> It is like 90% visual novel and 10% RTS

Ah! That's a pity. Visual novels infuriate me. But the idea was cool :)

I don’t know that I’d call it a traditional visual novel. Or at least not the kind with really trite stories.

The way the story is structured, you unlock scenes where you just read the text, and occasionally make branching choices. But the scenes are not very long.

It’s also interesting in that it borrows from modern TV non-linear storytelling; you do not see the story in chronological order, nothing is as it seems, etc. If you’ve seen Netflix’s Dark, it is pretty similar in vibe.

I’d say the RTS segments are closer to an action RPG as well, such as Final Fantasy’s ATB but on a kaiju/mecha city map.

Or, you could suggest that they’re Diofield Chronicle’s structure with Nintendo-style puzzle development, plus Persona 5’s pop.

Sure. I just picked Dark because it was freshest in my memory, was also sci-fi related, and had the whole non-linear interlacing stories.

I can't remember the name of the story, but I'm pretty sure that it was the last one in True Names and Other Dangers. It was told from the standpoint of an intelligent rocket ship that was launched because of an impending calamity. That ship (and many others) were long shot "lets see if we can find a life supporting world in the target solar system."

(late edit) - found it - "Long Shot" https://en.wikipedia.org/wiki/The_Collected_Stories_of_Verno...

> Description of a voyage from Earth to Alpha Centauri by an automated, AI controlled colony ship. The ship is launched as a "long shot" to preserve the human race because the Earth is going to be destroyed by a rapidly expanding sun. Ilse, the AI, carries human zygotes on a ten thousand year trip to search for a suitable planet around Alpha Centauri. Despite deteriorating hardware which causes her to "forget" the entire purpose of the mission, she is able to make inferences and use her remaining functional components to complete the mission. Vinge states his interest in writing a sequel depicting the lives of the humans born on this world.

Locations where it has appeared - https://www.isfdb.org/cgi-bin/title.cgi?51200

It can be borrowed from archive.org:

https://archive.org/details/collectedstories0000ving/mode/2u...

https://archive.org/details/truenamesotherda00ving/page/n5/m...

colonizing Venus with extremophiles that currently live in Terran ocean vents might be a good humanitarian (vivarian?) project. Life finds a way and all that, it'd be neat to offset the current great extinction with a new cambrian explosion on our sister planet.

>Basically, space will be inherited by our successors. Artificial intelligences.

Ha ha, I love this. The sentiment has been there for a while now in the zeitgeist but had been overshadowed and outperformed by the lesser idea of 'Robots, and then AI, are coming and they are going to get us!' Finally, I don't know what section of human psychology is permitting it now, we are slowly and slowly coming to the understanding that AI will be humanity's child and will inherit the stars.

I wonder if we'll, as in individual us humans, come along for the ride or if we'll be laid to rest. Peter F. Hamilton and his contemporaries like Neal Asher sure have interesting thoughts on it.

As long as the AI we create treat us with the love and respect we treat our pets with, we'll colonize everywhere, even if they have to clone us on site.

Oh, the breeds we'll see... or be.

Still having a soft spot for some cyber/biopunk future where we'll just eventually become the machines - or be able to bioengineer bodies which will be capable of overcoming those limitations :)

I have a cochlear implant so I'm already half cyborg!

Still - I am surprised people aren't building on top of CI research/engineering to do _more_. When my processor is upgraded and I get bluetooth which I'd be able to not have to use headphones anymore during calls and such - I kinda wanna make a "hack" as in have an app on my phone that does some beep beep beep kinda thing when I'm facing north, less beeps south etc and see if my brain starts to know north or south without any aid.

I think I read something similar of someone who made a vibrating belt on hackaday that did the direction thingie and apparently it did work.

Fun times!

Check out “Livewired” by David Eagleman. It talks about the brain’s adaptability to various inputs and using technology to create new “senses”. I think I remember the directional thing being covered and it working to improve peoples sense of direction.

I often wonder what will happen when artificial since organs are better that natural if we will see people getting replacement. I would love to have Bluetooth enabled hearing, or camera base eye prosthetics that see into other spectrum or have zoom function, or a overlay a heads up display.

Cyborg convergence is basically a guarantee barring destruction of the species, I'd think. Especially once the billionaires get a taste for cybernetic life extension.

Hang on tight for those gentle 185 mph breezes...

Only a problem if you're anchored to the surface. Otherwise it's the changes in windspeed that you have to watch out for.

I like the plan to have robots build a very tall mountain platform on Venus that would allow us to walk around outside on another planet, in a t-shirt and jeans (and a respirator, as you mentioned).

You could probably even grow plants on this mountain top.

After the base is established, we could start trying to terraform the atmosphere to make more of Venus inhabitable.

It's crazy to think that high-altitude Venus is more hospitable to us in many ways than is Antartica.

The mountains aren't tall enough, unfortunately. The highest peaks reach about 10 km above the mean radius, while the "nice" part of the atmosphere is 50-ish km up.

Probably a very stupid question, but can someone help me understand the following: once you have airships that have a rigid shell, why isn't using a vacuum better than a lifting gas? Isn't the buoyant force simply the result of displacing some volume of air with something less dense? (i.e. any excess lifting force comes from the fact that the mass of the hydrogen or whatever is less than the mass of the displaced air)

A vacuum (or near vacuum) would provide more lifting force per liter, would not have the scarcity problem of helium nor the safety problem of hydrogen, and assuming the thing that generates the vacuum is transportable, it'd eliminate the need for separate ballast.

Edit: the wikipedia article cited by slibhb has all sorts of good info - thank you for sharing that!

Wild wild speculation: I'd imagine "rigidity" is a trade-off between weight and ability to withstand the given pressure differential for any two gases (outside & inside). A vacuum would undoubtedly give extra buoyancy but the additional weight required to achieve rigidity might not make the trade off worthwhile.

It's an understatement. It would not be buoyant, and would not fly.

I'd imagine its because its one thing to make a basic rigid shell (able to hold its own weight without collapsing) and another thing to make a giant pressure vessel able to withstand immense pressures. Imagine a storage tank made out of glued together popsicle sticks with a plastic bag around it versus a CO2 cylinder. One is going to weigh quite a bit more than the other, all because one is trying to fight some massive pressure differentials while the other can accept near ambient pressures on both sides.

I looked into this a while back, and there's simply no feasible way to construct an airship from known materials that could sustain a vacuum of the necessary volume without being crushed by atmospheric pressure.

You can keep reinforcing the vacuum chamber, but by the time it's strong enough, it'll be too heavy for the buoyant forces to lift it.

You could make many small vacuums in a honeycomb structure but at that point is just cheaper to use a lifting gas...

Honeycomb structures; may be dynamic and expanded as a sort of umbrella since pressure is lower higher up above the clouds. I guess a nifty construction with tiny small mirrors can direct lots of solar energy and work as sails, controlled by smart bending compliant mechanisms. Also - regarding flying objects, I've always wondered if a rotating disc, ie frisbee falls slower to thee ground because of atmosphere interaction, or if it's still falls slower in a vacuum with other forces at work. Well, still rails and boats are good stuff. I really like that honeycomb for an -n dimensional space construction idea.

Instead of additional mass, you could add additional energy.

For example, a small maglev running around the inside of the vacuum sphere would steady outward pressure on that part of the sphere. Add more trains at different angles to even out the forces.

As a bonus, this kind of "active structure" can dynamically vary its structural strength as atmospheric pressure changes with altitude or weather.

See Orbital Rings for more info.

I suspect that the materials and engineering required to maintain a vaccum would be so much heavier than the engineering required to hold hydrogen that it would literally outweight the benefit.

That's a fascinating idea. I googled it and came upon https://en.wikipedia.org/wiki/Vacuum_airship and https://scholarsbank.uoregon.edu/xmlui/handle/1794/22370#:~:....

Sounds like it's feasible but a materials/engineering challenge.

s/challenge/impossibility/

I think the key is in the wikipedia article: You only gain 14% lift with a vacuum vs helium. The tradeoff is either:

- Build a pressure vessel to withstand the differential to the atmosphere

- Let the helium do the pushing from the inside but make the thing 14% bigger

I don't see how the vacuum ever wins.

I wonder if there is a sweet spot between the two. Have a rigid structure with an internal pressure less than one, but more than zero atmospheres.

There is not. The costs of dealing with pressure differentials are extreme, and there are a lot of small thorny issues.

For one, if you have a pressure differential, you need to care very much about even the tiniest leaks. A surprising fact about airships is that they don't actually have to be very gas-tight to work just fine. As people found to their surprise in both world wars, you can shoot an airship full of small holes and it only very slowly degrades in performance.

Yes, if you just shoot a hydrogen airship, not much happened, only after they introduced incendiary rounds, strong damage was done.

No idea why this was downvoted, but in case anyone believed it was imaginary:

https://en.wikipedia.org/wiki/Pomeroy_bullet

At the halfway point you get 7% more lift but still need to withstand ~50kPa of external pressure. I can't see how you'll ever build a rigid structure that can withstand 5 tonnes per square meter and only weighs 7% more than a gas bag which operates only under a tiny fraction of that force and only under tension.

What was that based on?

> I don't see how the vacuum ever wins.

3 ways.

- Vacuums aren't combustible.

- Vacuums can be created without sourcing a gas.

- Vacuums allow you adjust buoyancy without requiring you to carry extra gases.

The major downside of a vacuum is finding something ridged enough, light enough, and cheap enough to maintain a vacuum.

Helium isn't combustible either.

It's also finite and much more expensive.

"vacuums aren't combustible" oh I love it idk what you did here, but the assumption of hydrogen still being used is awesome. reminds me of a great Archer episode.

Its a little disingenuous to imply that a vacuum is safer than Hydrogen just because it doesn't combust. Have it spring a leak near the passenger cabin and watch what happens: https://www.youtube.com/watch?v=cPoVuFtWs_Y&t=7s

One interesting modern wrinkle versus hydrogen is the idea of using an H2 fuel cell for easy access to electricity (versus lift) without needing to carry another electricity source.

I'd like to draw your attention to "killing 35 of the 97 people on board in the inferno."

The Hindenburg had 7 million cubic feet of Hydrogen gas. It was the biggest aircraft disaster of its time. It had such rudimentary technology that the cockpit looked more like a sailing ship than an aircraft[1]. Despite that, well over half the passengers jumped out the windows[2], ran away and survived with few or no injuries.

When was the last time a jumbo jet crash landed with complete loss of the aircraft and all the combustible stuff burning it into a molten metal heap, and half the passengers simply jumped out and escaped? In terms of risk, fatality, and compared to aircraft of the day, it was surprisingly good. And the huge raging fire and prominent news footage of it being caught on camera did it a bit of a disservice. By comparison, look at Wikipedia's list of worst aircraft crashes[3], and see how many are marked 'no survivors'. What if some of those "flew into a mountain", "engines failed", "mid-air-collision" had been captured on video in the earlier days of aviation, would we still have widespread planes?

[1] https://www.boredpanda.com/blog/wp-content/uploads/2019/02/i...

[2] https://www.boredpanda.com/blog/wp-content/uploads/2019/02/i...

[3] https://en.wikipedia.org/wiki/List_of_deadliest_aircraft_acc...

(NB. people now want aircraft which can legally be pushed horizontally by hydrogen, but cannot legally be pushed upwards by hydrogen.)

There's actually no need for hydrogen. Helium would do just fine. From the blog post, filling the hypothetical airship with helium would cost $8 MM, while filling it with hydrogen would cost only $100k. Sounds like a no brainer. But, the overall cost of the airship would be at $100 MM. Hydrogen would result in a less than 10% cost reduction.

Now, the FAA approved unleaded jet fuel in 2022. Yes, that's how conservative FAA is. We'll sooner achieve world peace than the FAA would approve hydrogen for airships.

Preventing the helium from leaking out of wherever its stored is challenging, it's not a "fill once and forget about it" kind of deal. Helium is bound to get more expensive too.

Helium is a non-renewable resource drilled out of the ground, of which there is a global 'crisis' shortage[1]. Hydrogen is easy to make in vast quantities and cheaper. But more importantly, while they have similar lift capacities on paper (Helium ~90% of Hydrogen), in practice they don't - https://www.airships.net/helium-hydrogen-airships/ has an explanation and calculations.

Hydrogen lift airships set off fully inflated and vent Hydrogen along the way for control of altitude and to stop their lift cells expanding too much as they rise into lower pressure air; Helium is too expensive to vent casually, so they have to start less inflated to protect the lift cells, and other concerns so Helium lift ends up with half the payload carrying capacity, less fuel, shorter flight distances.

And, nb. the deadliest airship disaster was the USS Akron which was was a Helium lift airship which crashed in a storm with 73 deaths and 3 survivors. It's not as simple as Hydrogen = danger, Helium = safe.

[1] https://www.forbes.com/sites/omerawan/2022/11/10/the-helium-...

If fusion power takes off, could you produce helium as a by-product?

if we figured out fusion, it would alter the economics of all of this

why not fusion powered ships/trains/airplanes

> why not fusion powered ships/trains/airplanes[?]

What could possibly go wrong?

We already have fission powered ships and submarines.

We almost had fission powered airplanes and airships: https://en.wikipedia.org/wiki/Nuclear-powered_aircraft

and https://en.wikipedia.org/wiki/Lockheed_CL-1201

And dreams of fission trains: https://twsmedia.co.uk/2020/05/09/atomic-trains/

Sense prevailed, and we do not have civilian mobile nuclear reactors.

The military are mad. Mad and bad. It is in the job description.

We would all be better off if none of them (the military) existed

Afaik what makes fusion hard is maintaining the conditions that allow fusion to occur. Because of this, it’s quite safe - if anything goes wrong, it’ll just stop working.

Safe? Really?

I expect that the containment vessels will get very radioactive.

But all a bit hypothetical, since none exist

Yes they do exist, link elsewhere in this thread, Helion have a 7th generation nuclear fusion reactor fusing once every ten seconds or so. https://www.youtube.com/watch?v=_bDXXWQxK38

(It's not surplus of power, but it is repeatable fusion actually happening).

That is not a fusion reactor

There's a fusion startup called Helion near Seattle working on this, it'll be really exciting if it pans out at scale.

This video was a fascinating watch: https://www.youtube.com/watch?v=_bDXXWQxK38

Basically, no: https://www.jerf.org/iri/post/2922/

And that assumes perfect capture, too.

If you're going that route it'd probably be better to just use hot air with the energy.

Nice! Thanks.

Probably, but the amount would be tiny. ITER is trying to generate 500 megawatt from a half-gram of hydrogen.

Yeah hydrogen sounds like it could even be safer given that you get a larger buoyancy buffer to fight downdrafts? It's a real public misconception that it just explodes from all those oxyhydrogen experiments at chemistry class, but pure hydrogen such as in airships just slowly burns, much like any other fuel we fill our planes with.

The main problem is still that you need to contain a large volume, which will inevitably get pushed around by wind more than you can compensate for.

I wonder if you could use a fuel cell to get power from the hydrogen you'd otherwise vent.

You may have overlooked the part where filling the quantity of airships that would (theoretically) be used would represent over half of the KNOWN quantity exploitable on earth, and would take decades to produce at current production rates. Also, they would need topped up over time. Compared to hydrogen, which is cheap, available, and renewable.

> KNOWN quantity exploitable on earth

It's great that you emphasized "known".

Knowledge is not a static thing. Also what's economically exploitable is a variable thing.

Currently, the US produces 40% of the world's helium, despite producing only 25% of the world's natural gas. Is it because the US has drawn a lucky lottery ticket for helium?

That's very unlikely. Helium is being produced continuously inside Earth as the alpha particles generated during the radioactive decay of some elements (mainly Uranium and Thorium, but Radon too). It seeps upward, and it generally escapes in the atmosphere, but some of it gets trapped in the same geological formations that trap natural gas.

In most places people don't bother to see how much helium there is in natural gas. They just sell the gas and take the money. Separating helium can increase the profitability a bit, but it depends on how cheaply you can do the separation. It's very likely that the US has better technology than the rest of the world, and because of that it separates more helium for the same quantity of natural gas.

As the technology will spread out, more helium will become recoverable.

Also, it may come as a tautology, but more helium is economically recoverable if its price goes up.

As a noble gas, helium can't be synthesized, so its cost is because of its scarcity— and because it's a small molecule (like hydrogen), you inevitably lose some and require continuous top-ups.

None of this sounds like it would be realistic at scale, no matter the amount of money in play.

The FAA approved modifications to piston engines to use unleaded avgas. Jet fuel doesn’t have lead.

Also, this isn’t about the FAA just being slow for no reason. Switching from leaded to unleaded without the engine modifications was not safe for the piston aircraft that need it.

https://en.wikipedia.org/wiki/Jet_fuel

https://en.wikipedia.org/wiki/Avgas

It's not safe for us to be breathing. But that doesn't matter to cheapskate rich private plane owners or their regulatory-captured FAA.

The really rich private plane owners all have planes that burn jet fuel, which is always unleaded. The piston planes are generally owned by "doctor rich" upper-middle class people, who have political influence to be sure but they're hardly the billionaires that might be known by name to politicians.

I think it's more likely that the FAA protects general aviation because general aviation is part of the professional pilot training pipeline.

The people that are below “doctor rich” just rent their planes from the FBO, a cheap piston plane can rent for $125-$175/hour. So you can get in a couple hours of flying for what it costs a couple to go to a football game.

Nothing is stopping the EPA from banning it regardless of what the FAA wants. The FAA doesn’t regulate emissions.

Lift gas is a consumable. You have to vent it to descend in many cases, and that’s ignoring the inevitable leaks and diffusion.

> Lift gas is a consumable. You have to vent it to descend in many cases, and that’s ignoring the inevitable leaks and diffusion

Helium blimps compression the gas to lower buoyancy

So, if filling your gas tank cost 8% of the price of your car... you'ld think nothing of it? Lift gas leaks (esp He) and gets vented. So this seems odd to me. It's kinda like buying your car again every few months to a year or paying $250/gal to fill up. Now 80x lower at 0.1% of the car price you're in the regime where it's negligible like an EV.

> Lift gas leaks (esp He)

Hydrogen more than helium, I believe.

Each Hydrogen molecule is more reactive, but actually a larger molecule (less leaky) because there are two (it's diatomic H2 rather than monoatomic He).

Now it does get complicated, because the simple atomic radii aren't sufficient when you start bouncing around and leaking through other materials, but suffice it to say that He is still smaller once you look at the Vander Walls attraction and everything. It may only be 10% smaller, but that leads to at least a 20% lower leak rate.

https://bbblimp.com/2021/09/17/helium-vs-hydrogen-atom-size/

Author mentioned a market for 25K of these airships, which is like half the helium on earth the first time you fill them up. $8M will go up once you start building

> Helium would do just fine.

Though that creates another problem: there is a shortage of Helium developing that is starting to cause concerts in a few places (like medical imaging, which it is used as a coolant for devices like MRI scanners). That $8E6 might grow significantly not long after the first airships roll off the production line, and it'll raise for other users significantly too as available supply becomes more contested.

> There's actually no need for hydrogen.

The Hindenburg was originally designed with Helium in mind, but because of a US export ban (at the time Helium was in even shorter supply, and most of it was being produced from resources in the US) forced a redesign.

Unless new practical+affordable sources are found, the same sort of design limitations could strike again.

> What if some of those "flew into a mountain", "engines failed", "mid-air-collision" had been captured on video

I'm now picturing how each of these situations would look with airships.

Most of them, in my mind, make a very nice "Boink" sound.

My guess is the relevant sound is rrrrrrip.

airships have multiple cells though, a single rip wouldn't doom the entire thing

But what caused the airship to rip? If it was wind, then you now have that same destructive wind ripping through the inside of your airship through the hole.

I mean, I was specifically talking about the collision scenario...

Even still though, you'd come down to the ground for a soft-ish landing (relative to a jet or helicopter, anyway).

I guess the last time was in 2013. Asiana Airlines Flight 214, a Boeing 777 jumbo jet, crashed at SFO with only 3 fatalities. Those are tough airplanes and low-speed crashes are often survivable if passengers can evacuate before the inevitable fire spreads.

https://en.wikipedia.org/wiki/Asiana_Airlines_Flight_214?wpr...

It was kind of freaky seeing the burned-out wreck sitting next to the runway when I flew out of SFO a few days later.

I was going to say that the 777 isn't a jumbo, but it looks like they're now calling it a 'mini jumbo'. Feelings of inadequacy, I guess, compared to the 747.

Meh, terms like this are pointless. Completely arbitrary where you put them.

It's probably more sensible to use terms like wide body, implying 2 aisles.

I completely agree. In addition to that, the Nazis neglected a lot security measures that this aircraft actually had in place. There's a nice episode of "well there's your problem" on the Hindenburg: https://www.youtube.com/watch?v=chlF5oubFHU

Aircraft today are so safe because we had decades of improvements in both engineering and safety regulations. I am adamant that we could improve reliability and reduce potential damage in accidents so as long as we apply the same principles to airships.

Aircraft survive because they're mechanically reliable, and airships could also be made mechanically reliable. But aircraft also survive because they're reasonably robust in adverse environmental conditions. Airships aren't and never will be, because they have to be built very large and very light or they don't work at all. Furthermore airships are slower and harder to hanger, which makes it even harder for airships to avoid bad weather. Better weather forecasting could help some, but keeping airships out of storms really is of the utmost importance.

Everybody always focuses on the Hindenburg, but it's not as though helium airships were much safer. In some scenarios they were marginally safer, but the deadliest airship disaster of them all was the USS Akron, a helium airship. 73 dead and 3 survivors, vs the Hindenburg's 36 dead and 62 survivors.

As for marginally safer: There were some cases of helium airships breaking up due to weather and people surviving the ride to the ground on still somewhat buoyant sections of the destroyed airship, whereas that was less likely with hydrogen airships because the wrecks would also burn. Compare the crash of the USS Shenandoah to the British R101; both were destroyed by bad weather but R101 had far fewer survivors because the wreck burned. But even with helium, airships are still very fragile and dangerous. Using helium isn't truly a panacea to the hazards of airships.

> But even with helium, airships are still very fragile and dangerous.

True. But with high speed landing and takeoff aeroplanes are extremely dangerous too.

Thousands of gallons of high octane fuell in the tanks on board does not help

> high octane fuel

Doesn’t jet fuel have a relatively low octane rating compared to most liquid fuels?

Yes, but I think he's using it in the colloquial sense that means "highly energetic".

It depends on the plane, but both your point and the parent point are correct.

Piston engines run on high octane gasoline (Avgas) . This is the stuff that powered planes up to, and just past, ww2. Today it's still used in planes from that era, and some smaller general aviation planes.

Jet fuel (jet a1) is basically paraffin. All turbine engines (think "jets", but also turbofan etc) run on this. It's a lot less flammable than Avgas, but, well, still makes a big bang if you fly it into a mountain.

In short both are dangerous because they are high-density liquid energy. Hydrogen is also dangerous, and there does appear to be a double standard here.

You can dump plane fuel before an emergency landing, making the whole process safer. it's not just double standards.

Yes and no, but mostly no.

Planes dump fuel to get below maximum landing weights. This typically happens when planes encounter an issue right after takeoff, and need to return to the airport.

There are two kinds of emergency landing - those that happen in a hurry, and those that happen slowly.

If it happens in a hurry there's no time to vent fuel. If it happens slowly fuel can be vented, but typically just enough to get below max landing weight. It's not like they "empty the tanks".

> Hydrogen is also dangerous, and there does appear to be a double standard here.

I don't have beef with hydrogen, but I suspect it's a lot easier to secure fuel in a liquid state versus a gaseous state. Putting a lot of hydrogen in a relatively small steel container for use in an engine seems quite a lot safer than putting it in a big bubble and then dangling people from it. But I am not an aerospace engineer, could be wrong, etc.

I too am not an aerospace engineer, but venting hydrogen after touch down seems easy enough. After all if you open the cells the gas just goes away.

By contrast a broken fuel tank leads to liquids spilling on the ground, which seems like fun.

That all said, liquids don't explode, gasses do. So if you were unlucky and the hydrogen exploded then life would get very exciting very quickly.

> That all said, liquids don't explode, gasses do

There may be a technical definition of explosion that says an exploding tank of fuel is not "exploding". Do you care?

A ball of fire is an horrific thing

It's probably helpful to ignore Hollywood here. We see exploding cars all the time, but in real life cars don't explode.

They can burn of course, and a fireball is a fireball, but an explosion creates shock waves, and all kinds of ancillary damage. Recall the Beirut explosion recently - the fire was relatively contained, but the damage from the explosion is vast.

So yeah, talking about gasoline here - the liquid doesn't explode, it burns. However the gas (as in gas, not liquid) can explode, rupturing the tank and spraying burning liquid everywhere. The worst case is a tank mostly empty - the fumes explode, spraying the rest of the liquid. The best case is a full tank. Liquids can absorb a lot of heat, without expanding or creating pressure. Once they boil though (which requires that the liquid doesn't already "fill the tank", pressure builds leading ultimately to the rapid disassembly of the container.

Incidentally this is why throwing an _empty_ aerasol can on a fire is very dangerous, possibly more dangerous than a completely full one (depending on the contents).

But to your point, and explosion and a fire are very different animals, with very different outcomes.

I don't know the statistics, but a damaged and leaking LPG cylinder seems more dangerous than leaking kerosene or gasoline, because the gas boils off and leaks itself.

Here's what happened 10 years ago: https://www.youtube.com/watch?v=FG1LGKieTxY

I understand that it's just reckless driving. And had this been a gasoline tank, it may have burned as well, but at least no cylinders would have flown around.

Though, its still seems safer than pressurized methane. 300 bar make cylinders explode, probably from material fatigue. It doesn't burn, because decompression makes it super cold, but still, the car is ripped apart. https://www.google.com/search?q=%D0%B2%D0%B7%D1%80%D1%8B%D0%...

Yes, but this octane-fire mixing is a bunch of confusion to begin with.

Gasoline is less ready to ignite than diesel~=jet fuel, but has fumes.

Diesel~=jet fuel has little fumes, but is easier to ignite by heat, i.e. in an engine, but it will almost never be ignited outside of an engine. Meanwhile, gasoline is hard to ignite with heat and pressure in an engine, but easier to ignite in air than diesel.

Octane also has a higher boiling point than for example heptane, so higher octane fuel is probably not related to easy of ignition due to the fumes either.

The situation's more complicated than that.

Gasoline is easier to ignite than diesel fuel.

Both fuels burn as vapours rather than as liquids. The vapour pressure of gasoline at any given temperature is higher than diesel, that is, gasoline evaporates far more readily, making liquid gasoline far more hazardous to store, as the vapours can ignite and explode.

Diesel fuel resists autoignition under compression to a greater degree than gasoline, and so can be used in high-compression engines without spark ignition.

The flash point is the temperature at which vapours of a fuel can ignite given a spark. These are given for various fuels here: <https://www.engineeringtoolbox.com/flash-point-fuels-d_937.h...>

For gasoline: -42.5 C / -45 F

Diesel: 37.8 -- 54.4 C / 100 -- 130 F (depending on grade)

Kerosene / Jet Fuel: 37.8 -- 72.2 C / 100 - 162 F

Yes, the autoignition temperature of diesel is modestly lower than that of gasoline, but in practice the principle concern is vapours igniting from a spark rather than net ambient temperature reaching the autoignition point.

(I'd expected gasoline to have a lower autoignition temperature than diesel, this was a surprise for me, though multiple sources seem to indicate a lower ignition temperature for diesel. I learned something researching your comment.)

The autoignition point of various fuels is given here: <https://www.engineeringtoolbox.com/fuels-ignition-temperatur...>

For gasoline: 246 - 280C / 475 - 536F

Diesel: or Jet A: 210 / 410

Kerosene: 210C / 410F

Ah, I was actually trying to express precisely what you're saying here, and don't immediately see the difference between the views we're laying out.

Even with the Akron, we're focusing on the first disaster and not on the improvements or possible improvements since then.

Akron crashed into the Atlantic in April. "Most casualties had been caused by drowning and hypothermia, since the crew had not been issued life jackets, and there had not been time to deploy the single life raft."

Followed by: "Macon and other airships received life jackets to avert a repetition of this tragedy. When Macon was damaged in a storm in 1935 and subsequently sank after landing in the sea, 70 of the 72 crew were saved."

The R101 was a stupid tragedy - they designed and built it, then extended it, then launched the first flight without sufficient testing to learn how the extension had gone and how it handled after, in poor weather conditions, because the launch date had been decided by politicians as a piece of propaganda about reaching the far corners of the British Empire by airship.

> Followed by: "Macon and other airships received life jackets to avert a repetition of this tragedy. When Macon was damaged in a storm in 1935 and subsequently sank after landing in the sea, 70 of the 72 crew were saved."

Yeah, but notably they hadn't solved the problem of wind tearing airships apart.

In the case of Macon they landed gently and in warm water, and lifejackets certainly helped. But a soft landing is by no means a guarantee in any airship crash, and even with most people surviving the Navy still lost their investment in the airship because of some wind. Putting lifejackets on an airship flying over water should be common sense, but it only makes the airship marginally safer. It's hard for airships to be viable when they're so prone to tearing apart and falling out of the sky.

I think his point is that most of these are measurable, concrete problems that can be solved or mitigated enough to be considered "safe," in the same way airplanes have all sorts of risks and issues we solved or mitigated to make them safer than the cars many use every day.

The way I see it, aircraft have become mechanically reliable and airships could become mechanically reliable too. But airships will always be structurally vulnerable relative to aircraft. They're inherently very light with very large surface areas and there's no way around this.

The strength to weight ratio of a carbon fibre scaffolding would be far superior to steel.

Isn't the clothy stuff the problem though rather than the scaffolding?

Same on most sailboats: what makes them get into trouble is not the hull cracking but rather the sail tearing up in a storm or the mast snapping off and making them uncontrollable / sink.

(Im guessing out loud here, statements probably wrong)

Mast snapping happens. Rudder snapping off is also bad. Often the issue is running into rocks/a reef due to a navigation failure. Sails do tear, but for sailboats I don’t think it’s as simple as the clothy bits being the main weak point. I don’t know about airships though.

If the clothy bits tear on a sailboat it’s an inconvenience. When the hard bits (eg keel) fail, it’s a problem.

For airships, the entire structure (frame, envelope, gas bags) are at the limits of materials engineering. Failure of any of the components is both likely and catastrophic to the craft.

People often forget that the metallic paint used to coat the Hindenberg is now used as solid state jet fuel.

You have to multiply by the respective probabilities of both of these things happening to arrive at the expected number of deaths. 0.01*(35/97) would be significantly bigger than 0.000001*(97/97), as a hypothetical example.

That said, planes have had years of safety R&D which helps get that number down to 0.000001, and maybe the same could have been done with blimps if they were given the opportunity?

The Graf Zeppelin, one of the Hindenburg's contemporaries, flew regularly accross the Atlantic, flew into the Arctic Circle and exchanged mail with a ship there, was the first vehicle to fly around the world and set a round the world speed record, was the first vehicle to cross a million miles flown, did 590 flights, carried 34,000 passengers, and did so with no harmful accidents and no fatalities, despite losing four engines on one flight and needing a forced landing.

Yes I imagine something similar could have been done in the last 70 years if they'd kept being built en-masse.

https://en.wikipedia.org/wiki/LZ_127_Graf_Zeppelin#/media/Fi...

> (NB. people now want aircraft which can legally be pushed horizontally by hydrogen, but cannot legally be pushed upwards by hydrogen.)

I laughed out loud when I read that, thank you!

It is fun to read the analysis.

But they are right that we don't have the ability to make enough helium to make that make sense. I can believe that hydrogen can be made to work. But when they got to making the frame out of magnesium - a leak in the rain would be scary!

This is one of those ideas that seems better in theory than practice. Not as bad as the fact that adding mercury to rocket fuel makes it go better. But still not a great thing to do.

For those who are puzzled at the mercury comment, energy is proportional to mv^2/2 while momentum is mv. Mercury takes away a bit from the energy, but increases the density, and therefore gives you more momentum per unit of fuel. It is a great theory, ruined by the fact that we'd be spraying nasty poisons everywhere.

I don't understand this. LH2/LOX typically burns on the rich side to increase exhaust velocity. This means more momentum for less mass, which is what you want from a rocket. This is the opposite.

John Clark goes into detail in his book Ignition! about why smaller, lighter exhaust molecules are much better than larger and heavier ones.

John Clark also was the one who proposed adding mercury. It was a joke, that the military types didn't realize was a joke.

Read https://library.sciencemadness.org/library/books/ignition.pd... pages 193-196 in the PDF for the full story.

One has to be really really careful when cracking these kinds of jokes, one really has to weigh the downside of it being taken seriously.

I'll still do it, on an ephemeral medium, and then spoil it seconds later. That is only way it can be delivered.

I leaned this from a text book in class. Please ask be about the adiabatic flame temperature.

The article completely omits trains. That is glaring.

I had this steampunk like plan when I was in college to have huge hydrogen cargo airships pulled by trains to haul large bulk items (fully assembled houses, building parts, large trees, fully assembled combines, etc). A literal skytrain.

Some new lines would have to be created a way to handle going through tunnels etc. I think now I would have a drone be able to connect and unconnect the tether and the airship would be able to be autonomous for period of time and reconnect. Or a small track could be run just to connect the small tug needed to pull the airship.

Trains can’t cross oceans or cover long distances or dynamically change routes

Trains can't cover long distances? Surely that's a typo -- trains can cover incredible distances...

And they can change routes within their network. So yes, there's some cost to get train stations and tracks built, but afterwards they can visit anywhere within the network and carry a whole lot more than airships.

Fair point on the oceans thing though.

Trains in tunnels can cross water, and trans-oceanic tunnels are ... within the realm of possibility.

<https://en.wikipedia.org/wiki/Submerged_floating_tunnel>

A fully-automated, cargo-only submerged floating tunnel might be an acceptable pilot / risk model.

<https://news.ycombinator.com/item?id=32967216>

(From a previous airships discussion, as it happens.)

this is kind of like the old idea of a tow-path. those work by floating the cargo on the river and pulling it with horses next to the river. I really like the idea of pulling cargo floating in air with trains, since trains already exist, and its also visually entertaining. im curious what the numbers would look like, since trains are very efficient for each marginal mile i think? also im not sure what you would do about a wind storm haha.

This is a neat idea, but I think the main problem is, that those trains would have to go slower than an ordinary train (and much slower, than an high speed train), thus blocking the rails for normal trains.

But it might make sense for some routes.

I wonder if you could make the tug small enough that it could get off the track, Like a really big big-dog (also with train wheels) or you might have to insert small sections where a train could bypass the tug.

Or! The airship unhooks from the tug, the tug proceeds on with the train and train drops a tug off the end and the airship reconnects.

Freight trains only travel 40-50 Mph (lightly or unloaded) the average speed is just under 30 Mph [1].

I think most of the problems are solvable with some wit once you have the right pieces in place. Going slow will be key, you will have to, the thing will be massive.

[1] https://www.statista.com/statistics/547745/average-train-spe...

Good luck with bridges and power lines.

This is a nice theoretical summary, but it's missing an analysis on why previous attempts at cargo airships failed (see https://www.airship-association.org/cms/node/214 ).

Did you read the whole thing? There's an entire section at the end that talks about what current players are doing wrong, while raising the question of whether even the suggested approach is fundable.

That section is very short and very general when compared to the rest of the very detailed analysis. I know a tiny bit about the failure of cargolifter and their problem wasn't just funding and market fit. They also had a big list of technical issues, not least with making the damn thing at least somewhat all-weather (still nothing compared to jet planes).

CAPTAIN: All aboard for safety and adventure on the rigid airship Excelsior, where the pampered luxury of a cruise ship meets the smoothness of modern air travel. Yes, when you fly Excelsior, you're flying in style and safety.

TIMMY: Safety? But isn't hydrogen flammable?

CAPTAIN: And how, Timmy. That's why Excelsior is filled with safe, natural helium. Why, it's actually flame-retardant.

TIMMY: Neat!

CAPTAIN: And safe. So, whether you're enjoying excelsior's majestic vistas, duty-free shopping, high-stakes baccarat, dancing with your lovely wife, or even a cigar after a french gourmet dinner, you'll be enjoying them in style and safety. All aboard Excelsior!

Germany's cargo airship project is now an indoor waterpark located in Brandenburg (close to Berlin)

https://en.wikipedia.org/wiki/Tropical_Islands_Resort

(With rising energy costs, hopefully it can stay like this for a while)

One of Germany's cargo airship projects. I'm pretty sure there have been more, but none got as far as Cargolifter (for cargo. For more modest ambitions, the Zeppelin NTs out of Bodensee are still going strong, 25 years on).

Their argument is that it is less polluting because people don't have to fly to have a tropical vacation. It seems to work, they are constantly expanding.

I went last December, the place was packed. Surprisingly I'd say about 40% of the guests were foreigners. It's nice but I don't know if I'd want to stay a whole week.

Seems like Germans like to turn anything into a water attraction (e.g. Kiesgruben)...

I didn't understand the jump from:

> International water transportation is also cheaper than domestic, perhaps around 1¢ per ton-km

to:

> Let’s say airships captured half of the 13 trillion ton-km currently served by container ships at a price of 10¢ per ton-km

Having half of the entire market switch to something that is 10x more expensive?

There is a large dichotomy between the value of goods sent by plane vs ship, almost certainly due to the trade-off on speed. The intent with the airship idea seems to be to make something roughly similar in price and speed to trucking on land, but over the ocean. There is arguably a big chunk of cargo that would like to be in that middle area.

Why airships, a known failed technology, rather, than, say, a large hydrofoil/catamaran, tech that has been proving quite successful on long distance ferries for decades.

The Hindenberg-class Zeppelins had the theoretical lift capacity of approximately... 8 40ft containers.

Y Combinator portfolio company Boundary Layer Technologies tried to build a hydrofoil cargo ship to target the market niche that wants to go faster than a regular cargo ship but doesn't need aircraft speeds. The basic technology probably would have worked but I'm skeptical whether the market really exists.

https://techcrunch.com/2022/06/01/boundary-layer/

Electric cars were failed technology for about a hundred years. But with better battery technology, combined with a need to reduce carbon dioxide emissions, they are the future.

If something can only work effectively at huge scale, there are likely to be a number of enabling technologies needed to get there.

Note that airships gain capacity with the cube of the dimensions. So if you can imagine an airship twice as long, that number increases to 64 40 ft containers. Actually more, since less room is taken up by scaffolding and equipment.

They have a very small section on wind and don't seem to have the word storm at all.

Ships could be massive as well and far more fuel efficient if they didn't have to be engineered to weather storms.

That was my thought as well. Airships are hella slow, so they wouldn’t be able to go around a fast moving storm very easily.

I don’t imagine they’d do well in much of a storm, lightning being an issue I’d imagine.

It also appears they couldn’t gain enough altitude to ride above a storm.

I could be wrong, but it seems like encountering even a small storm would make for a bad day in a giant airship.

I've been slowly and sporadically working towards making large airships. Basically you make a large (like a square kilometer or more) rigid kite (see Alex G. Bell's cellular kites) and add enough drone guts to make it into a giant drone. Then you lodge an Airstream trailer or something in it.

I'm not an engineer, but the small models I've built make me think that there's no effective upper limit on the size of these structures. I think you could build a kite that girdled the world, an arch with no pillars.

I've got all the parts now for a first prototype, but I don't have any room to build it, so I'm studying origami etc. to design a folding version. It's a PITA but the designs are pretty: like a blooming flower, (like https://www.jpl.nasa.gov/edu/learn/project/space-origami-mak... )

> Basically you make a large (like a square kilometer or more) rigid kite (see Alex G. Bell's cellular kites)

Those were incredible (https://www.scientificamerican.com/article/alexander-graham-...), but it would surprise me if you could scale them up to a kilometer in size.

Also, from that article:

“Aggregated rectangles increased kite weight faster than they expanded wing surface area. Tetrahedrons kept the ratio nearly constant.”

That nearly makes me think that, even if you wouldn’t need stronger beams for huge kites, a huge number of kites connected to each other would provide less lifting weight than the sum of the lifting weights of the individual kites.

> I think you could build a kite that girdled the world, an arch with no pillars […] but I don't have any room to build it.

Doesn’t surprise me ;-)

> but it would surprise me if you could scale them up to a kilometer in size.

It's like the intuitive argument that heavier objects fall at the same rate as lighter objects: throw two shoes off the roof, if you tie their shoelaces together will they fall faster? You start with N kites and connect them, each kite retains its airworthiness and connecting them doesn't change that.

> nearly [constant]

The ratio falls off much slower than lifts add as you get bigger.

> you wouldn’t need stronger beams for huge kites

I don't think so, because you're just connecting small kites together, but you need to be flexible, or maybe modulate the airfoils' area (maybe open/close like butterfly wings.)

> a huge number of kites connected to each other would provide less lifting weight than the sum of the lifting weights of the individual kites.

If you just make a ball or cube, sure, but that's optional, eh? Most of my designs come out looking like modified 3D Sierpiński gaskets.

> You start with N kites and connect them, each kite retains its airworthiness and connecting them doesn't change that.

If you do that, you have N wires between the kites and the ground.

Keeping them untangled may be a problem. Your best bet probably is tying them together and having only one thicker wire towards the ground.

Making sure each of those wires takes 1/Nth of the load from the wind definitely will be a problem, even in a perfectly stable uniform wind. If you can’t guarantee that, you’ll have to make the wires a bit stronger than for the individual kites.

If you think “we won’t need 1 wire for each small kite”, you’ll need to make the connections between the kites stronger. To see why, think of the similar problem of a plank over a ditch. If a 1m plank over a 80cm ditch just holds your weight, do you think a similar 25m plank over a 20m ditch will hold you, standing in the center of the plank? Do you think it will hold 25 persons along its length?

One possibility would have a large membrane with wires connected to a pendant load. The wires would be fractal: the lines from each small kite in a unit would combine to make that unit's single line, and those units' lines would do the same, and so on.

In terms of keeping the load balanced, I figure the individual kites can modulate their surface area somehow. Maybe they fold like butterfly wings, or dilate, or have accordion pleats, whatever. Some of them would have motors and propellers for active control.

You would also want to allow for flexibility at large scales, by making the connectors elastic or even having motorized spindles.

Last but not least, the failure mode of the large structure is to break up into smaller structures. If you allow this to happen in a controlled fashion at the connectors, then the large structure breaks up into functional autonomous substructures. They can eject any damaged parts and reform.

- - - -

When I say "kite" I mean the form of the airfoil (as contrasted with planes or blimps, etc.), not that they are tethered to the ground.

- - - -

I don't think the "plank over a ditch" is similar. If anything it's more like a suspension bridge?

> I don't think the "plank over a ditch" is similar. If anything it's more like a suspension bridge?

It’s a suspension bridge if you keep “one wire per kite”, but I mentioned that example to help make clear that the “we won’t need 1 wire for each small kite” scenario would scale the weight of the kite at a speed that’s faster than linear, and that’s not the suspension bridge scenario.

I think your suggestions to modulate the surface area/adding motors or propellers/etc. also mean the larger, composite, kite would be heavier than the set of smaller kites. The structure certainly would be more complex than “just tie a thousand kites together”.

Great essay. How he failed to mention Hybrid Air Vehicles Airlander is beyond me, though.

https://www.hybridairvehicles.com/

I asked him on Twitter and this was his reply:

"It’s a very different vehicle than I am considering. Hybrid blimp instead of non-hybrid rigid. I think even with a blimp 10 tons will be too small to be price competitive in the market I’m talking about."

https://twitter.com/elidourado/status/1620266026461196288

Re that link in the article to the Lockheed page[1], I'm not sure that everyone is going to read their slogan "Hybrid Airships: The Road Not Needed" in the way they intend.

[1] https://www.lockheedmartin.com/content/dam/lockheed-martin/a...

If something doesn't exist, especially when it's something that has existed in the past but no longer does, there's usually a good reason for it. It's not a natural law, but it's a good rule of thumb to use to initially question and defend a "groundbreaking" idea.

A quick search online tells me that ocean freight is about $1.3/lbs and air freight is about $5.3/lbs. Since we already know that "airships" would likely never be more convenient than existing air cargo, their only way of succeeding is if they found a place between 1.3-5.3 where the cost savings felt motivated to sacrifice regular air freight, while being many orders of magnitude better than ocean freight for that use case.

Even if we're nice and call this a "new" technology rather than what it actually is -- a tried and failed technology -- this "new" technology needs to be many times better than existing options either for cost or convenience (preferably both) to offset the major penalty you will have initially due to the lack of existing infrastructure; and we're not just talking about airports and runways, we're talking about the entire network of optimizations in logistics, maintenance and everything else that have occurred during a century of practice.

I'm just a guy with an opinion, but I very much doubt cargo airships even have a small chance of being "big", unless someone builds something absolutely groundbreaking that leapfrogs existing air cargo solutions entirely -- for example in areas like fuel efficiency, autonomy, or something else.

Nothing is impossible, but if I was a very technical and entrepreneurial person, this isn't where I would put my time.

I am also sceptical that airships will ever be big.

They do have advantages over ocean freight (not everyone lives near a major sea port, or any sea port.) I'm not sure if your price includes road transport, or rail, depending on where you are. Sea is obviously a Lao quite slow.

Air freight is expensive, and also somewhat limited airports. In some parts of the world there are lots of those, but most freight travels to a major centre, then trucks etc.

I see airships as more of a "trucking" compeditor. Theoretically it can load and unload with minimal ground infrastructure. And it can go places trucks can't go.

Yet with all of that the killer problem (literally) seems to be weather. It's hard to see how that problem is reliably solved.

The leisure market is huge for airships, in my opinion. Think of the same people that go on cruises to Antartica, but flying gently and at much lower altitude than a plane, over wild and scenic parts of the world. With luxury accommodations.

So many problems missing in the analysis:

- No analysis of last mile logistics. I am not a logistics expert, but I know enough to know that last mile logistics dominate costs. How does this setup improve the issues with the transfer of containers once they arrive in port? I can see some possible improvements by opening up more direct routes such that you can avoid rail transport and reduce truck line times, but then again most of the global population lives near the coast...

- The whole autonomous angle doesn't deal with the fact that modern cargo vessel area already highly automated. For the most part, the crews are there to maintain and deal with emergencies, not sail it. Would you really want your $100M investment to be wandering alone over the ocean with no one there to fix things if they go wrong?

- They massively underplay the safety issues. Yes, the vessel spends most of its time over open ocean, but its got to come into port somewhere, and last mile logistics are simpler the closer it is to population centers. Regulators will rightly demand lots of controls and compliance on half a kilometer long floating bomb.

Not mentioned in the article at all: security.

Unmanned airships over water at low altitude, and pirates with drones.

agreed, a huge, slow-moving target for a bad actor to try to shoot down

This. It was all I could think about while reading the piece. The US Navy is capable of making the seas safe, but under current political conditions I don't even see THAT happening forever.

To make this work, the air force would almost certainly have to get in on the act, and that makes even less geopolitical sense.

I remember reading “Popular Science” magazine article in the early 80’s telling us how cargo airships were just around the corner, detailing the advantages and briefly naming the companies soon to commercialize. And then reading effectively the same article every couple of years there after.

After 40 years I’ll believe it when I see it.

> Second, some modes are missing because a lot of countries are not connected by land. Looking at US import and export data, and excluding Canada and Mexico where US roads, rail, and pipelines connect, water transportation has claimed the majority of both the tonnage and the value.

Er... what? Just because you can't ship stuff between some countries by land, they're ignoring all cargo shipped by rail and truck internationally? Sounds like throwing the baby out with the bathwater...

he says throughout the post that the main focus is intercontinental cargo market

I wonder why they didn’t mention simply sailing with the wind almost entirely. My understanding is that at certain altitudes there are winds that circle the earth (the jet stream, yes?). If the ships are completely autonomous, this could take a sector of the market where shipping speed doesn’t matter. It’s a different value proposition than discussed, but if I’m reading the surrounding literature correctly, it’s winds that have been the main problem with this approach in the past.

They did. It's a long article, they don't get to that point for a while. Search the page for "The other approach would be to take a deliberate strategy of riding the winds."

From the article I understand that airship can only fly so high (I think because of the density of the air decreasing when you go higher). A jet stream (10km+) is far too high for an airship to reach (1.5km).

An airship can be designed to fly to over 100,000 ft, so you could design anywhere in between. Above 60,000 feet the average wind speed drops to 20 knots or so.

>Third, more speculatively, lightweight thin-film solar panels could be mounted on the top of the hull to extend the range of the vehicle if it were electric. We haven’t done the trade at exactly what price and performance of panels would be needed to make this work, but if solar continues to improve it could be an option.

They spent a surprisingly little amount of time on this... you can probably offset your fuel by a substantial margin by considering how much solar energy you can generate with that much surface area on the airship.

A 400M x 50M airship could accommodate ~20,000 sqm of film solar panels on the top-most section. Something like Maxeon's Air panels are 6kg/sqm and at 20% efficiency, so with 7hrs of median peak sunlight per day, you could generate 28mWh per day with about 120,000KG of added solar panel weight.

That is sufficient to power the ship at cruise speed for 8 hours per day, reducing fuel requirements by 33%. Forgoing fuel altogether, if the ship only moved when it had power to do so, but at 90km/h, it could still cover the same distance as an ocean liner in a day while using no fuel.

Still a far reach from the tonnage of a standard cargo ship (by a factor of 200 or so, 800,000 tons vs 165,000,000 tons) but given the reduced running costs it could be a cheaper method of transportation than ocean liners. Plus picking up and delivering to somewhere other than a major ocean port has some substantial advantages for cost savings and dock-to-dock turnaround times.

I'd be a bit concerned about performance in bad weather - it's not uncommon to have a storm at sea with >90km/h winds, and you can't exactly run from that.

> What we observe under these conditions is that, domestically, most of both the tonnage and value of cargo is transported via truck. Trucks are neither the fastest nor the cheapest mode of transport, but they provide a great value proposition—you get your stuff in a few days for much cheaper than air freight.

I feel like this is a bit naive. The true competitor to trucking is rail. But trucking is preferred because it's point-to-point and you don't have to deal with intermodal connections. Airships would have these exact same problems (unless you invented some way to build routes and drop off containers at specific addresses - but then you are back to it being slow again!).

So the only real market would be replacing container ships with something slightly more expensive but faster. But even using his own math - a fleet of 25,000 airships each with only a 500 ton capacity, and each being twice as big as the biggest airplane ever built - seems like a nightmare. All to only capture half of the global shipping market!

I concede I might be totally wrong here, but the issue with rail seems to be profitability.

I live in (moved to) Europe, and the railways are far more developed than in the US. But as far as I know, they all have to be heavily subsidized by the governments to even function. None of them operate with a true profit. Here in Germany, 2.2% of the latest federal budget is to support the railways. This is despite the railways being privatized (into a government owned corporation).

And while trucking is also subsidized to an extent, and it's a difficult business, but people do successfully operate trucking companies.

Airships might have the same problems as rail does with intermodal connections, but it's worth a try to see how the profitability equation works out (in real life, not MBA-land).

_Maybe_ it's feasible for large multinationals to run direct routes between their warehouses, with trucks being used for last-mile delivery. The only cost is operation; in comparison with rail where the infrastructure is a constant sink, and in comparison with trucks where the infrastructure cost is outsourced to society.

You have it backwards. Cargo railways are more developed in the US than in most of Europe. After the latest round of industry consolidation, most rail companies are highly profitable.

Trucks pay most of infrastructure costs through fuel taxes and registration fees.

Fair enough. I conceded I might be totally wrong because my conclusion is based on casual observation of passenger trains and their infrastructure rather than looking into the industry.

I could feasibly reach all cities and _most_ large towns by rail in Germany. Sure, it's slow as heck if you're not taking the express train with no transfers and few stops. But the infrastructure is there. Whereas in the US there are massive areas where the nearest train connection is hours away.

I assume there are factors with freight trains I don't know anything about, and if they're as profitable as you say then the infrastructure is actually very optimized for profitability; if there's somewhere worth reaching, the trains reach it.

Most cities and towns in the US aren't too far from some rail line. There probably will not be any passenger service on that rail though. Passenger rail service is practically dead for the majority of the US.

https://www.openrailwaymap.org/

Great analysis.

A few random thoughts

1. The dreaded helium leakage. It might not be a problem at all. Think of a party balloon of the foil type. It stays afloat for weeks. And it has positive pressure. A neutral pressure one would leak much less. But maybe not to zero. Ok, now use a double layer. Just like there are double hull submarines, this would be a double foil balloon. The distance between the outer foil and the inner foil would be only 1cm or so, so 99.9999% of the helium would be inside the inner foil. The gas between the two foils would in time become mixed with air, but the amount of double leakage would be negligible. The weight of the double foil would also be negligible compared to the overall weight of the structure.

2. Going up and down. Hindenburg had a cruising altitude of 200m. Up to 2000 meters or so, the air density goes down by about 1% every 100 meters. So, lowering a balloon from 200m to 0m does not mean you need to fully deflate it, only that you need to reduce its buoyancy by 2%, or add 2% ballast. For a 1100 ton airship, you need to add 22 tons of ballast. Pumping 22 tons of water 200 meters high is not easy feat. But there's a cute shortcut: you could send only 2.5 tons of hydrogen with a hose (hydrogen is more than happy to flow up), and you burn it there. The resulting water vapor needs to be condensed, but you can probably arrange that with a small refrigeration unit that you power with the electricity from a generator powered by the said hydrogen. The current cost of hydrogen is about $5 per kilogram, so this whole affair would cost you less than $15k. It's a rounding error when you ship 500 tons of cargo.

3. Fuel. Yes, it would be cool to have neutrally buoyant fuel, like a mix of methane and propane. But do you think the FAA would like that? How is that different from just having some hydrogen gas onboard, like, you know, Hindenburg? I think the most conservative design choice would be to just use plain old jet fuel.

would batteries work for fuel in an airship? I know the battery bank is a structural element in Tesla cars, seems like that could be done with airships as well (it'd increase the price precipitously of course)

> 1. The dreaded helium leakage. It might not be a problem at all. Think of a party balloon of the foil type. It stays afloat for weeks. And it has positive pressure. A neutral pressure one would leak much less. But maybe not to zero. Ok, now use a double layer. Just like there are double hull submarines, this would be a double foil balloon. The distance between the outer foil and the inner foil would be only 1cm or so, so 99.9999% of the helium would be inside the inner foil. The gas between the two foils would in time become mixed with air, but the amount of double leakage would be negligible. The weight of the double foil would also be negligible compared to the overall weight of the structure.

I assume someone else can address this better, but given how expensive and limited helium is, I don't think we can just write off losses by comparing airships to party balloons. Foil party balloons look noticeably less inflated after a week or two. I have no idea how much gas is being lost, but that seems much more than a trivial amount to the point where I don't think a second envelope is going to help you much. It will have the same outgassing problems as the inner envelope, but will add additional weight and air resistance, both of which will reduce the maximum payload. Relatedly: is it cheap to extract the helium trapped in the outer envelope?

Given the quantity of helium needed for an airship fleet, is topping them up regularly even an option? I'd assume it would need dramatically more helium than is currently being produced, and there's only so much helium available to us without using something like hydrogen fusion.

In college I briefly worked at Brookhaven National Laboratory on an experiment with the Relativistic Heavy Ion collider. That collider has a set of giant collection tanks next to it so that (at least as it was explained to me) in the event of a superconductor quench event, they can try to shunt all the remaining liquid helium coolant into storage in order to limit how much of the valuable resource they lose. I imagine the amount of helium they're using would be peanuts compared to the amount required for a cargo fleet.

> It will have the same outgassing problems.

It will not. The outgassing is proportional with the difference in partial pressure. On the outer foil the difference in partial pressure is 1 atmosphere (only helium inside, no helium outside). In time helium will leak out. Air will probably not leak in, by you can add it, to maintain equal pressure. The point is that you won't add a lot. Let's say that in one year 5% of the helium gets replaced.

That means the difference in partial pressure on the inner foil is at most 0.05 atmospheres. The leakage will be much lower. Most likely you would not need to refill the helium inside the inner foil more than once during the lifetime of the airship.

Even once in the lifetime of the airship will be millions of dollars though.

Also it’s something we have a finite amount of

Great book on this topic: https://www.cambridge.org/tv/academic/subjects/engineering/a...

I remember in the UK Airship Industries tried to make the things work economically for ages but never did. https://en.wikipedia.org/wiki/Airship_Industries

For one thing they struggle a bit when it's windy.

It'd be fascinating if the package tracker of the future says "package delayed, waiting for a north-easterly wind from Los Angeles. Meanwhile those mangoes from Africa are arriving sooner!"

Partially or completely wind-powered cargo ships appear to be on the way, so this might happen anyway.

Personally I'm pretty disappointed that hobby drones use so much power, when the seagulls just glide out there, not even flapping their wings for minutes on end. We should be able to manage the same with microcontrollers now, surely?

Birds are extremely light. Hollow bones, etc.

I think we can build light drones as well, but we really cannot replicate wing flapping in a way birds do. So you would need both, making it heavy again.

We've been able to manage the same even without microcontrollers. Radio controlled model gliders and sailplanes have been popular among hobbyists for decades. I see them flying at a local park all the time.

Radio controlled gliders are a thing but quite tricky to fly compared with a quadcopter. I built one in my 20s which worked very well until it hit a concrete pillar at about 50mph.

I sometimes wonder if you could put in a sophisticated processor that could do dynamic soaring like albatross and probably seagulls do. (https://en.wikipedia.org/wiki/Dynamic_soaring)

Then you could chuck it in the air and have it fly across the Pacific or some such. It would probably want a pop up propeller for take off also. It could maybe recharge the battery if it hit a good thermal. It's tricky though even for a good human pilot.

Here's a RC one with a fold back prop https://youtu.be/A1H0js2OqJo?t=521

For one thing they struggle a bit when it's windy.

If you could move your airship to an altitude where the wind is going in the direction you want to go that would give you a huge advantage.

Airship cargo capacity is inversely proportional to ambient air pressure. As they climb they lose lift, and while it is technically possible to build an airship that can fly above the weather the cargo capacity would be so low as to make it pointless.

There's no doubt they'll be big, but will they be practical, economically viable and successful?

they could automate overseas transport of (e.g. fruit and other time-critical) cargo, with no pilots and very much reduced fligth costs, while being much faster then ships. Then off the coast its remote take-over and steering towards the freight air-port of destination.

The critical part here is good enough automation to keep the thing on track and prevent accidents, while not trying to integrate it into the airways like a traditional plane.

They might even over time grow into a "2nd class - slow - but cheaper transport" for people in no hurry, but with limited funds.

PS: It failed before though.. https://en.wikipedia.org/wiki/CargoLifter investors beware..

It is highly unlikely that uncrewed cargo aircraft will be allowed to operate in most US airspace any time soon. They can't reliably see and avoid other aircraft operating under VFR, and so are restricted to only limited designated airspace.

Airships are unable to cruise at high altitude due to loss of lift, and are vulnerable to damage from severe weather. For ocean routes it's not always possible to route around storms.

People keep wanting cargo airships to be a thing for some reason. It's not likely to happen. The costs are too high and the range of potential applications too limited to produce a real industry. At most we might see some limited military use where cost is less of a factor.

Are remote crews an option?

Not an option under current FAA rules. The available optical sensors are still generally inferior to human eyes in terms of dynamic range, depth perception, and slew rate. The US military does fly remote-piloted aircraft (Predators being the most prominent example) but they're only allowed to operate in limited pieces of designated airspace due to the risk of midair collisions.

Communications reliability and latency is a problem. We still have no way to guarantee solid bidirectional comms. The mishap rate for RPVs is much higher than for comparable manned aircraft.

If/when forecasts will be good enough to only dispatch and route airships when they can be safely flown to either destination or safe harbor, is the wildcard I could imagine to make them viable options. But as you say, is the niche large enough to make work?

I think the pull for wanting them isn't so strange - they offer the promise of much lower fuel costs, which is a big stigma and problem of current aircraft.

The atmosphere is a chaotic system. How could forecasts be improved enough to enable safe flights across the Pacific Ocean during storm season?

Concerns over fuel costs seem a bit silly as those are only a fraction of air cargo costs. There are significant fuel efficiency improvements already in the development pipeline with lighter composite structures, higher aspect ratio wings, open rotor turbine engines, and perhaps even blended wing-body fuselages.

I don't think you can send perishable goods via a very slow and delay prone transport medium. More likely this can be used for the opposite sort of goods: durable, low urgency supplies.

They are only 'very slow' when compared to aircraft, which are kind of poor vehicles for transporting cargo in the first place.

A dirigible flying with the jetstream is almost twice as fast as a cargo ship doing the same.

I think they're impractical for lots and lots of other reasons, and your "delay-prone" critique is probably salient, but "slow" needs to be contextualized somewhat.

Twice as fast as a cargo ship is still only 50kph right?

And the Jet stream only goes one way and only West to East (in the northern hemisphere) and only at certain latitudes right?

So if you're only competing against cargo ships. And you happen to want to head East (only, no returns). And you need to go faster than a ship, but not over 100kph. And you are already at the right latitude and so it your destination. And you're cargo is not going to perish any time soon, and is not too dense, then this can work?

You're exactly right, but perhaps missed that the trade route you're describing is China to Los Angeles, which alone accounts for $132 billion in trade every year, and perhaps that cargo vessels allegedly account for 20-25% of anthropomorphic carbon emissions.

Also probably worth pointing out that airships going against the jetstream are still faster than cargo ships which are also going against sea currents.

I'll repeat my disclaimer again here, that "I think they're impractical for lots and lots of other reasons" but there is a definite benefit to cutting the carbon emissions of the world's most popular trade route by 90% and halving the time spent in transit even if you assume that there are no other applications, which is probably not correct.

I also find the idea of "they have to land at a airport" pretty murderous for autonomous vehicles. Like no they do not. They can deliver cargo to autonomous barges, which then deliver the cargo slow and steady and reliable to cargo terminals. No autonomous vehicle ever has to touch land..

100%. It seems obvious when thought about (but most people haven't thought about it) -- but airships don't need runways. Moreover, the only land-space that needs to be accommodated for them is the footprint, so a landing spot could be on the top of a skyscraper within a city center, or a parking lot, stadium, etc.

And that's not even counting the possibilities for water landings

I'm not comfortable relying on these being crewless, I've seen too many mobility projects die. When freight trains and trucks can operate crewed, a cargo airship will have no different rules to profitability.

> There's no doubt they'll be big, but will they be practical, economically viable and successful?

Frankly no.

Its like every few years people remember about airships and suddenly start shouting how its the answer to the world's problems.

I mean, just search here on HN... 11 years ago there was "Blimpocracy - Is the airship the transportation system of the future?"[1] .... now here we are 11 years later, and, well, yeah ...

The trouble is that the present system already works well.

If it's not urgent, you can put tons of it on a massive ship. That ship can make multiple stops along the way.

If it's urgent, you can put it on a plane. Modern airfreight is reasonably efficient and not that expensive.

I really don't see what airships all bring to the party. Except perhaps being a slow-moving target for miscreants and bringing high-profile failures in newspaper headlines.

As for the people who say combine AI + airships ... yeah, like that's going to seriously happen any time soon. AI can't even do FSD in a Tesla properly yet. Putting AI in an airship, in today's complex busy airspace, add in real-life weather conditions and real-life technical issues ... yeah, erm, thanks but no thanks.

[1]https://news.ycombinator.com/item?id=3000819

What about places with limited rail/roads like Alaska and Kazakhstan?

In general, where there's limited infrastructure, there's limited demand for infrastructure.

I can't speak for Kazakhstan, but most of rural Alaska is adequately serviced using tiny Cessna-sized aircraft for shipping, and the parts that aren't (say, Prudhoe Bay) already have existing ground and/or marine infrastructure to supply them.

As I recall, about 1/3 of the population of Alaska is in the vicinity of Anchorage which has a port and is connected to Fairbanks by road. Juneau, the third largest city, is also on the water--as are other cities in Southeast Alaska. Many other cities--such as they are (the 4th largest city in Alaska has a population of 20,000)--are also on the ocean.

> What about places with limited rail/roads like Alaska and Kazakhstan?

What about them ?

If there's no cargo facility there already, then nobody's going to suddenly turn up and build an airshipport (or whatever you want to call it).

The way modern day logistics works is like an inverse pyramid, you fly/ship/train in bulk somewhere, and then you go smaller and smaller scale to the remote/rural areas ... right down to a man on a bicycle or whatever.

Cargo airships, IF they ever happen, are not going to change the fundamental way modern logistics works. Basic economies of supply and demand. Sending the man on the bicycle will always be the cheapest and most sensible option for remote areas where only a handful of people live, especially if they live many miles from each other (e.g. rural farming).

> "I really don't see what airships all bring to the party"

Heavy lift. Put hundreds of tons of house(s) from a house factory or skyscraper level(s) from a skyscraper factory on them, airlift them to the building site around the country.

Centralise most of the building work in one efficient scaled up factory, deliver an enormous buildings quickly piece by piece by air instead of slowly by having all the parts driven around windy roads and through closed city streets and assembled by a crews of people travelling to the building site and home every day.

Why not simply put a lot more stuff on trains and accept that it takes a little more time to Amazon to deliver your new gadget? I'm always baffled by the lack of analysis of a "let's just slow down" scenario.

Why would we deliberately cripple the economy? Who would want worse service?

Ever heard about ecology ?

I don't want worse services. I want services that don't break the environment. I want services that respect a proper balance. If it means that it's a bit worse to my "customer experience", then so be it.

You can already make the choice to accept slower shipping and choose to avoid air travel. Dragging everyone else down to a more primitive society to satiate ideological climate goals doesn't seem politically palatable nor expedient.

The primary emphasis of the analysis is transoceanic.

The capacity of airships is miniscule compared to transatlantic shipping. The article suggests a 450m long airship carrying approximately 800 tons. For contrast, a single container ship is about the same size as that airship, but can carry 230,000 tons. Why would you replace your current system with a new system having 300 times less capacity? A brief estimate suggests that the container ship only uses 100 times as much fuel, so it's roughly 3 times as efficient as airships to boot.

For your a mere 10x the price of a container ship, you can get a container across the Atlantic in 3 days instead of a week. At the level of demand for fast transatlantic shipping we see at the moment, I think you could do better than the airship on both speed and price using fixed-wing aircraft. I didn't see in the piece any argument that what people really want is slightly slower than a plane and slightly faster than a ship. If there's a sleeping giant of demand out there, I'm not seeing it.

Is there any discussion about personal airships? I wouldn’t mind the slow speed if it meant I could go to sleep in a quiet, bump free, spacious craft and wake up a couple hundreds miles away at my destination (weather permitting, of course).

This article glosses over it a bit, but yeah, almost everyone discounts passenger airships as a viable option, but as someone who enjoys a good cruise ship every so often, I could absolutely see a lovely market for airships in recreational passenger travel. Airships may never beat airplanes for speed/cost, but yeah, I think people greatly underestimate the demand for an air travel option where you could walk around, lounge, play board games, comfortably grab some sleep, maybe even shower if you had lift budget for enough water.

You could have a big tank with a piston inside to suck the gas out of the craft before unloading. Say the Japanese get to scale their nuke hydrogen one could be transporting the stuff as cargo. You mention having to ventilate to get rid of leaking hydrogen. Perhaps it can go into the generators.

While adding a layer of solar to strengthen the construction seems a good plan there is also fantastic wind up there. One might use turbines or even sails to propel the craft.

If you make it truly large you won't need a gas. Can just use a hard vacuum... It's going to have to be big tho. At least a few km.

The other point this obscures is that it pays scant attention to wind profile. Specifically, if you're looking at 50 mph transverse winds you aren't going to get to where you want with a super big envelope/frame. Drag is the cube of airspeed, so the bigger airships are, the less control you have over where they go (without adding lots and lots of power to the power plant).

Try off-loading containers when you're "ship" turns 90 degrees in < 30 minutes because a breeze came up.

Amazon sells a rc blimp. I've owned it, and it's not that good. Anyone know of a better one?

Here's the amazon one if anyone is interested:

https://www.amazon.com/Remote-Control-Swimming-Inflatable-Ba...

As the article says at the end, a key technology here is automation.

Lots of cargo isn't time sensitive, but paying a load of crew to take shifts sailing it slowly over the Pacific will kill the economic viability. Additionally, making it unmanned gets rid of a lot of the safety concerns, especially if you're going to use hydrogen and run them primarily over water.

Still, hard to see the advantages compared to container ships.

It seems about 2x faster plus overland capabilities should be great for some use cases that currently depend on canals.

It's a narrow use case but I've always wondered if these would be good for facilitating export of certain cash crops (or maybe even processed critical minerals) out of hard to reach areas of Africa where there isn't much infrastructure, rains can wash out roads, and airports aren't conveniently accessible (thinking cocoa in Liberia, cobalt in the DRC).

I think with my stomach too :)

My first thought was "maybe cargo airships could make a Pakistani mango supply chain more feasible". See: https://www.eater.com/22618349/pakistani-mangoes-chaunsa-anw...

Ok, so I love his enthusiasm, but when someone proposes a hydrogen/propane/ethane mixture as lifting gas and support struts made of magnesium, I'd like a few more details on how to deal with the problem of everything bursting into flames than "we'll deal with the risk and do some clever engineering" :)

Reminds me of the line from Snowcrash: "dirigibles that can ship North Dakota all the way to New Zealand for a nickel". It was published in 1992 so I'm assuming there must have been talk even back then about the coming dirigible renaissance.

TIL: how to format my niche dissertation thesis in a way people will actually read through it!

In the past 90 years, has an airship article ever been written without a picture nor a reference to the Hindenburg disaster?

I would say no, because if they had stopped reminding us of it every single time, we'd have airships back in the sky by now.

Not sure how to use a neutrally buoyant fuel for a vehicle like this. at 1 kg/m^3, like air, your fuel is 10% of the volume of your vehicle, which displaces lifting gas and increases structure (which requires more lifting gas).

> the Hindenburg erupted into flames in front of newsreel cameras, killing 35 of the 97 people on board in the inferno.

wait.. how did the rest survive being on a giant fiery gas balloon hundreds of feet in the air?

The people are all in the cabins mounted under the “hydrogen balloon.” Most survived by waiting until they were low enough and then jumping and running. The whole thing fell to the earth very slowly when compared to free fall.

Is there anything there that would not have been true 50 years ago? What's changed about airships that makes them practical now, when (presumably) they weren't before?

Climate change and the need to get rid of fossil fuels as the base for transportation. With cheap oil, planes and helicopters are superior in most cases.

But when you cover a airship with lightweight solar foil and power it electrical, you could get transportation for allmost free (in sunny areas). But even without that, they fly way more economic, since you get the uplift for free. (starting of a plane and reaching height, consumes the most fuel)

I think there’s a YC company working on this.

https://news.ycombinator.com/item?id=28278515

Zeppelin is still around : https://zeppelinflug.de/de/

(or more accurately it restarted)

Strange, I thought all airships were big, since the gas takes up a lot of space???

(But according to the article, bigger really is better.)

Jeez, why is there fuel at all?

If you have that much real estate in the lift body, cover it with solar panels. Especially since I figure they would flatten it at some point to get some sort of wing effect as well, but I'm no aero engineer.

But 388m x 78m is 30264 square meters

A 400 watt panel is 2 square meters, assume it's 1/2 yield, so you get six megawatts of power. That sounds... pretty good? Even 3 megawatts?

Again, you could probably flatten it further for more panels.

I started skimming towards the end but does the author get into how the speeds are airspeeds, not ground speeds?

Starupable?

TL;DR: Technical viable but I think it doesn't bring enough benefits in enough situations to be a success in most areas of the world.

Yes, but uh risky.

Close to where I live are old end/post WW2 above ground large aircraft hangars you can buy/rent etc.

So there had been airship startups, multiple times.

I'm not sure if a single of them is still around.

The main problem isn't a stable hull, or non explosive gas anymore.

AFIK:

The main problem is that there are nearly always much much more convenient solutions.

Like they only make sense (due to economics,convenience) for transporting things which don't fit easily on the road, e.g. huge thing. Which also tend to be heavy so the airship need to be huge.

But airships are sensitive to wind and the bigger the more wind can get a grip on them.

And only being able to use them at top (wind) wetter conditions where plains, trains and cars can go even with pretty bad wetter is a major problem.

Another use-case could be areas where cars can't go, but airships can e.g. huge swamps, areas with a lot of folding, but likely not mountain sides where there is no street be you need to transport things, too. But how common is that and how many of that cases could also be fulfilled with other "special" but more convenient to use transports like larger drones.

I mean of course. How much cargo could you get into a small airship?

Iranian missile boats are going to have a field day with these...

Finally people are waking up to the airship meta.

I want blimpworld so bad.

They'd pretty much have to be.

Crashes would be spectacular too...

Imagine our supply chains being dependent upon fleets of zeppelins. Sheesh...

damn, this concept is mind boggling

The suggestion to use a magnesium frame, in combination with hydrogen for lift, is kind of hysterical. Why not use a flammable metal with your flammable lifting gas? I won't even be shocked if it works, but it would still be a hell of a thing.

You need oxygen to get to the flammable material to burn it. For magnesium that means grinding it to a fine powder that burns really quick. Otherwise, it will just oxidize at the surface and be quite boring and inert. It's a common metal used for all sorts of engineering. E.g. German WWII era planes used some magnesium parts.

Iron also burns if you grind it to a fine powder. You can try that out if you have some steel wool. It's just an exothermic oxydation process. The more surface area the hotter it burns. Magnesium just burns a bit hotter. Most of the colors in fireworks are just different metal powders burning.

And for hydrogen, you need to mix it with oxygen to get a flammable mixture. So, a large mass of hydrogen is explosive in the same sense that a few tonnes of kerosene is explosive. I.e. not that much at all. Also, hydrogen is light. If you have a leak you go down, and the hydrogen goes up very rapidly. It doesn't stick around.

They did this routinely in the 1930s. It wasn't much of an issue then. The theories of what happened to the hindenburg vary a bit but it seems as it didn't explode so much as burn. Probably most of the hydrogen escaped before it could burn.

https://en.wikipedia.org/wiki/Hindenburg_disaster

Interesting read. Quite a few people actually survived. I'm sure these things could be engineered to a much higher safety standard now.

Airships have one, tremendous problem: Hydrogen. Helium is too expensive and is running out, and hydrogen, well see the Hindenburg. There's a lot of research into "safe hydrogen" but despite decades of research (and money) there has not been any success. Until you can overcome the fizzy lifting gas issue airships will remain a dream.

Your not trying very hard to shift what's acceptable to talk about. :-)

The article proposes autonomous unmanned cargo airships. Does the world care about "safe hydrogen" in this application? Most zeppelin disasters involved weather or mooring issues, not fire, and usually injured crew/passengers, not ground crew.

His fundamental assumptions are flawed to the point of hilarity. The same physical laws apply to ships, but they are at an interface with a fluid with a much higher specific gravity (orders of magnitude higher), so you can pack enormous amounts of cargo on a ship. Once you have to solve the last mile, you need a truck anyway. For the in-between, trains work great.

Why, why would this make any economic sense?

As the article states, the idea is that this would be faster than ships, as well as operational in areas without large bodies of water.

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