61–70 of 95 posts
Earlier quoted context omitted.
Disposable paper hot-air balloon for lift, retractable antenna? Or perhaps better yet: disposable paper kite?
Your comment, while I assume you earnestly meant, is enigmatic of the gap between what the lay person may think works at sea and the very harsh and unforgiving reality of the Sea. Source: my father was an engineer at a marine engineering company
Earlier quoted context omitted.
Yes, but a keel is also limited right? It's still possible to tip over and - if potentially submerged, not come back up? But to be honest, I have very little knowledge on this topic, so maybe a keel is all it needs!
As long as it not fills with water, I'd say it will right it self. On a traditional boat the sails can dig down in the water and needs to be released rather quickly, and you don't want the hatch to be open, but neither of this seems to be a problem here.
Saw the video yesterday on YouTube. I wonder what happens if they get into very strong winds or very strong swell - if they tip over, do they get up by themselves? What happens if they submerge? Apparently they figured out how to do it, but my question is, how exactly are they doing it?
One advantage of this kind of wing sail is it's "self trimming". With the tail/tab in neutral position, it'll always weathervane to follow the wind. With the tail tab deflected somewhat, it'll weathervane with some amount of angle of attack. So even in very heavy winds, all it needs to do is back off on the angle of attack and it should be in a relatively stable state.
Earlier quoted context omitted.
If high endurance air drones are advanced enough, you can coordinate sea and air nodes to make a mesh that avoids clouds and line of sight all-together so you don't have to string the network over the sea level horizon. Maybe have autonomous platforms that allow both to refuel too if they use hybrid systems.
Balloons, maybe.
This is not hard, and for 8km height you could manufacture them for under $2k/piece. Even if they'd be made to work with hydrogen, as that raises the demands on the construction. If you'd find the FCC to be willing to allow something like this and are able to handle both thunderstorms and just the general wind load on the tether, this should not be hard.
[0]: https://en.wikipedia.org/wiki/Single-wire_transmission_line
> “It’s fuel, consumables, and I don’t even want to tell you what our satellite bill is for data,” Interesting - the circumference of the earth is roughly 40 thousand km. If these could manage to lift an antenna either 140m (or equivalently 70m for all participants) - distance to Horizon should be roughly 40 km. So a thousand boats could form a theoretical relay net around a theoretical line in the ocean reaching aro…
That's interesting. 70 meters is a pretty dang tall aerial for something with that small a footprint to hold aloft, though. That plan also limits their range of movement severely to keep the network intact, but I guess they could use satellite as a backup. Maybe a kite of some kind, but how do you reliably launch and retrieve it? I dunno, I think in practice the satellite may be cheaper.
I've been (slowly and painfully) working my ways towards constructing a self-reproducing robo-boat swarm for a few years now, ever since learning about the Great Pacific Garbage Patch.
My idea is to set up a simple artificial ecosystem of interacting bots that collect and recycle oceanic trash to create more of themselves. This permits exponential growth, making it realistic to attempt to tackle such a large-scale problem from a relatively tiny "nucleus".
I want to use Molten salt oxidation [1] to convert trash to "synthesis gas" [2] then feed that through a water column to convert CO+H2O to CO2+H2. Recover the hydrogen for power (more power, the MSO reaction is exothermic) and feed the carbon dioxide to algae tanks. The algae can be processed to create both plastic membranes and a kind of ocean-water-proof glue. Rather than build boats, you make spheroids out of the plastic and glue them together to make foam. (I call it "spittlebug architecture" [3].) Foam and tendons allow you to make e.g. artificial hydras [4] which can be attached at their bases to long conduits (also make of glue-foam) to collect and sort trash and carry it (via peristalsis) to the MSO unit. The long hydra-lined conduits can be arranged in a (huge) spiral which can then be driven to rotate by positioning of sails and rudders embedded in the conduit. The MSO unit would be in the center.
The idea, at every stage, is to do and use the minimum of action and materials and energy throughout the system to maximize scalability and throughput-per-unit.
The outputs of the system will be power, fresh water, building material, and packets of recovered molecules (the ones that aren't made of H C or O) to hopefully be reused.
Glue + membranes + geometry + pressure = An open-ended variety of light-weight rigid structures with a very easy construction method. [5]
[1] https://en.wikipedia.org/wiki/Molten_salt_oxidation
[2] https://en.wikipedia.org/wiki/Synthesis_gas
[3] https://en.wikipedia.org/wiki/Spittle_bug
[4] https://en.wikipedia.org/wiki/Hydras
[5] https://en.wikipedia.org/wiki/Inflatable_air_cushion & https://en.wikipedia.org/wiki/Air-supported_structure
> “It’s fuel, consumables, and I don’t even want to tell you what our satellite bill is for data,” Interesting - the circumference of the earth is roughly 40 thousand km. If these could manage to lift an antenna either 140m (or equivalently 70m for all participants) - distance to Horizon should be roughly 40 km. So a thousand boats could form a theoretical relay net around a theoretical line in the ocean reaching aro…
Caveat wind issues, raising a balloon would work. But still you would need a big enough balloon to hold 70m of coax up and the antenna. On the plus side you could slowly electrolysize water with the solar panels to fill your balloon with hydrogen :-). So you would only need to carry spare envelopes rather than a bunch of helium tanks.
> “It’s fuel, consumables, and I don’t even want to tell you what our satellite bill is for data,” Interesting - the circumference of the earth is roughly 40 thousand km. If these could manage to lift an antenna either 140m (or equivalently 70m for all participants) - distance to Horizon should be roughly 40 km. So a thousand boats could form a theoretical relay net around a theoretical line in the ocean reaching aro…
Caveat wind issues, raising a balloon would work. But still you would need a big enough balloon to hold 70m of coax up and the antenna. On the plus side you could slowly electrolysize water with the solar panels to fill your balloon with hydrogen :-). So you would only need to carry spare envelopes rather than a bunch of helium tanks.
Can you cover most conditions with a balloon and a kite? Can you make a kite which can be inflated to turn it into a balloon? (Looks like clever people have already been here: Kytoon – a balloon with a couple panels of fabric to make it behave like a kite in wind and a balloon in calm.) A two string kite can also be used for propulsion in many conditions.
Depending on transmitter power, I have to think that in 2018 a transceiver is lighter than 70m of coax cable compared to a power pair. Put a relay at the top and talk to it from the boat. (10 watts over 30ga for 70m at 48v is about 66% efficiency for a mass of only 30 grams. You can trade off mass with power, wire size, and respect for the life of you maintenance technicians. The product always looks better at 200 volts!)
Earlier quoted context omitted.
Disposable paper hot-air balloon for lift, retractable antenna? Or perhaps better yet: disposable paper kite?
Your comment, while I assume you earnestly meant, is enigmatic of the gap between what the lay person may think works at sea and the very harsh and unforgiving reality of the Sea. Source: my father was an engineer at a marine engineering company