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Cargo airships could be big

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Re: Cargo airships could be big

#81

Post by shagie »

bobthepanda wrote: post #53
echelon wrote: post #33

Earlier quoted context omitted.

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…

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.

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...

Re: Cargo airships could be big

#82

Post by Someone »

carapace wrote: post #19

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…

> 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 ;-)

Re: Cargo airships could be big

#83

Post by vintermann »

rsynnott wrote: post #37
netsharc wrote: post #28

Earlier quoted context omitted.

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?

Re: Cargo airships could be big

#84

Post by thrill »

haarts wrote: post #59
comfypotato wrote: post #39

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 wind…

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.

Re: Cargo airships could be big

#85

Post by ben_w »

kspacewalk2 wrote: post #80
ben_w wrote: post #58

Earlier quoted context omitted.

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.

Re: Cargo airships could be big

#86

Post by andrewflnr »

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.

Re: Cargo airships could be big

#88

Post by andrewflnr »

mabbo wrote: post #79
jodrellblank wrote: post #66

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…

> 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.

Re: Cargo airships could be big

#89

Post by tiagod »

credit_guy wrote: post #77
jodrellblank wrote: post #66

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…

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 conservativ…

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.

Re: Cargo airships could be big

#90

Post by jodrellblank »

credit_guy wrote: post #77
jodrellblank wrote: post #66

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…

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 conservativ…

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-...

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