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Tether Talk: Energy in the Jovian Republic

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Sat, 2011-02-12 15:14
#1
Demonseed Elite Demonseed Elite's picture
Tether Talk: Energy in the Jovian Republic
I'm very fascinated by the idea of making the Jovian Republic a less one-dimensional antagonist in Eclipse Phase, and I've been compiling a bunch of notes for something I want to write up. One of the ideas I consider often is the Jovian Republic as an energy economy, with much of its old-style economy backed by the energy trade. Of course, this depends on the Jovian Republic being able to generate a lot of energy and since I'm not a physicist, I'm asking for input and feedback. [url=http://en.wikipedia.org/wiki/Electrodynamic_tether]Electrodynamic tethers[/url] seem like they'd have the potential to generate a lot of energy in Jupiter's magnetosphere, especially if the tethers are attached to inner Jovian moons and use the moon's orbital momentum to drag the tether. I imagine that the power could be collected and then beamed across Republic-controlled space to power habitats and spacecraft or possibly be used as weapons to protect the Republic's domain. So my question is: is this feasible? Would the tethers be able to generate sufficient energy to build a Jovian economy out of?
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Sat, 2011-02-12 23:19
The Green Slime The Green Slime's picture
Re: Tether Talk: Energy in the Jovian Republic
Interesting. I'm no astrophysicist either but I have doubts that the Jovies could be a major player in the system-wide energy market given the competition has the Sun in it's pocket. It's like comparing the Nicaraguan oil fields to Saudi Arabia's. Utilising tethers and other clever devices to capture the radiation streaming off the planet and the moons may be sufficient to provide the junta with reasonably ample energy independence (though to what degree will be a closely guarded secret of major political import). Their main game, I like to think, would be in strip-mining their many multicoloured bizarro moons for precious minerals. And the gravity well of course, which oftentimes gets them whatever they want anyway.
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Sat, 2011-02-12 23:53
Demonseed Elite Demonseed Elite's picture
Re: Tether Talk: Energy in the Jovian Republic
The Green Slime wrote:
Interesting. I'm no astrophysicist either but I have doubts that the Jovies could be a major player in the system-wide energy market given the competition has the Sun in it's pocket. It's like comparing the Nicaraguan oil fields to Saudi Arabia's.
Well, not necessarily system-wide, but regional. For a fee, the Jovians could beam power to spacecraft passing near the Jovian system while also using the same beams to threaten spacecraft that do not pay the toll to use the Jupiter gravity slingshot. The sun produces much more energy, but the sun is pretty far away from the outer system. But more importantly, can the tethers provide enough power for the Jovians to sustain themselves?
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"It's a poor sort of memory that only works backwards." --The White Queen, [i]Through The Looking-Glass[/i] [img]https://lh6.googleusercontent.com/_zGgz13n3uzE/TWWPdvGig-I/AAAAAAAACI8/y...
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Sun, 2011-02-13 06:49
Arenamontanus Arenamontanus's picture
Re: Tether Talk: Energy in the Jovian Republic
Yes, there is a lot of energy in the Jovian system. Check out http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.29.5508&rep=rep... http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.29.5508 They are mainly looking at small spacecrafts, but even these can get a megawatt of power and decent amounts of acceleration from a mere 10 km tether - inter-moon transports can likely be made cheap since you do not need reaction mass or can use tethers to heat a VASMIR unit. This paper calculates that you could get 10^15 J if you deorbit a moon like Amalthea, http://www.esa.int/gsp/ACT/doc/AF/ACT_AF_ACT_090319_Orbital_energy.pdf While Solano is presumably out of question, there is always Metis, Adrastea, Thebe and the other ring-moonlets. Then there is the 10^12 W Io flux tube. Put antennas or coils into that, and you will get a terawatt of power all the time. Just the thing to power a major antimatter manufacturing plant for your Destroyers, or to beam it as lasers to vaporise ice reaction mass of merchant vessels.
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Sun, 2011-02-13 10:43
Demonseed Elite Demonseed Elite's picture
Re: Tether Talk: Energy in the Jovian Republic
Thank you for the links! I'd seen the second paper, but the first was new to me. I've been reading a number of them, but too much math and my eyes start to glaze over. ;) What sort of tether length are we looking at to generate substantial power from moons like Metis or Adrastea? Would multiple shorter tethers work just as well as a single long tether? And yes, it was my thought that the Io Flux Tube would house a number of tether/collider orbitals that served as antimatter factories.
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"It's a poor sort of memory that only works backwards." --The White Queen, [i]Through The Looking-Glass[/i] [img]https://lh6.googleusercontent.com/_zGgz13n3uzE/TWWPdvGig-I/AAAAAAAACI8/y...
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Sun, 2011-02-13 10:50
Arenamontanus Arenamontanus's picture
Re: Tether Talk: Energy in the Jovian Republic
Demonseed Elite wrote:
What sort of tether length are we looking at to generate substantial power from moons like Metis or Adrastea? Would multiple shorter tethers work just as well as a single long tether?
I think the energy will be proportional to the total length of the tether, so the longer the better - until you reach the limits of conductivity at a few tens of kilometers using current materials (and presumably longer with superconductors). Having more tethers likely works, although ideally you want the tether to be at a right angle to the velocity and magnetic field for maximum efficiency, so you will likely mainly use tethers in two directions (but to deal with the current issue multiple tethers might be a good idea - however, now the currents will cause magnetic fields that will start to affect the bundling of tethers too). There are fun problems too. Tethers can start to act as pendulums due to the interaction of tidal forces and electromagnetism. And unexpected current surges have cut tethers.
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Extropian
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Mon, 2011-02-14 08:00
Demonseed Elite Demonseed Elite's picture
Re: Tether Talk: Energy in the Jovian Republic
Arenamontanus wrote:
There are fun problems too. Tethers can start to act as pendulums due to the interaction of tidal forces and electromagnetism. And unexpected current surges have cut tethers.
I imagine tether engineering to be a lucrative (and potentially dangerous) field in Jovian space. Especially since their bioconservative views prevent them from taking advantage of radical morph design for radiation shielding. The way I've been imagining it, robotic shells are controlled from nearby radiation-shielded habitats or ships and enslaved AI are sometimes used to operate energy stations that aren't fit for human residence.
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"It's a poor sort of memory that only works backwards." --The White Queen, [i]Through The Looking-Glass[/i] [img]https://lh6.googleusercontent.com/_zGgz13n3uzE/TWWPdvGig-I/AAAAAAAACI8/y...
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Mon, 2011-02-14 09:34
nezumi.hebereke nezumi.hebereke's picture
Re: Tether Talk: Energy in the Jovian Republic
Transporting energy has costs. You can't just transmit it from Mercury to Pluto without serious loss. Putting it in a battery and shipping it also has significant costs (not least of which is time, and the ability to adapt to shifting market conditions). Jupiter will be in a better position to serve its local area, including its section of the Belt, than Mercury. However, serving the area further out? What does Jupiter offer that you can't get from any of the other gas giants? Its only real advantage is its orbit will sometimes take it closer to outer-system points than its competitors. Maybe it has a helluvabig transmitter which gives it a leg up?
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Mon, 2011-02-14 10:29
Demonseed Elite Demonseed Elite's picture
Re: Tether Talk: Energy in the Jovian Republic
Regional power transmission is what I'm talking about, not system-wide. Basically, spacecraft traveling between the outer and inner systems can swing by Jupiter for a beam of power, as well as use of the Jupiter gravity slingshot, assuming they pay the tolls (or take the risk of being fried by a laser). Within the Jovian Republic, a few key power stations on the inner moons generate power using tethers and beam it elsewhere in the Republic, providing power to orbital and moon habitats.
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"It's a poor sort of memory that only works backwards." --The White Queen, [i]Through The Looking-Glass[/i] [img]https://lh6.googleusercontent.com/_zGgz13n3uzE/TWWPdvGig-I/AAAAAAAACI8/y...
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Mon, 2011-02-14 14:12
nezumi.hebereke nezumi.hebereke's picture
Re: Tether Talk: Energy in the Jovian Republic
If you have a solar sail it's no problem. If you're riding anything else... I honestly don't know how you'd transfer a large quantity of energy to a ship flying so fast and presumably pretty far from the planet. If you call ahead they can probably accelerate a ship containing a quantity of fusile materials or whatnot to connect with you. Maybe some sort of microwave set up?
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Tue, 2011-02-15 14:27
root root's picture
Re: Tether Talk: Energy in the Jovian Republic
root@Energy in the Jovian Republic [hr] If you know the trajectory of your customer's ship, beaming energy to it isn't a difficulty. Any serious energy concern set up in the Jovain system will have power relays, and the transmission losses for vacuum are given by the Friis transmission equation for the interested and/or masochistic. One thing I like about this tether idea is that it would be an incredibly dangerous profession for a Jovian, and will therefore have a sort of folk mythology build up around it like we have for things like ice-truck drivers. There is no way that a teleoperated sleeve can be used, as the very nature of the strong electromagnetic fields generated by power harvesting makes electromagnetic communications difficult. The technicians would be highly trained, highly payed, and high risk individuals along the lines of our current deep-dive welders or even the people who go scuba diving to collect golf balls in water hazards frequented by alligators.
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Thu, 2011-02-17 08:09
Demonseed Elite Demonseed Elite's picture
Re: Tether Talk: Energy in the Jovian Republic
root wrote:
One thing I like about this tether idea is that it would be an incredibly dangerous profession for a Jovian, and will therefore have a sort of folk mythology build up around it like we have for things like ice-truck drivers. There is no way that a teleoperated sleeve can be used, as the very nature of the strong electromagnetic fields generated by power harvesting makes electromagnetic communications difficult. The technicians would be highly trained, highly payed, and high risk individuals along the lines of our current deep-dive welders or even the people who go scuba diving to collect golf balls in water hazards frequented by alligators.
I like the romantic imagery of Jovian tether engineers, but I wonder if it would really work like that in many cases. The tethers can be turned off while being repaired, so in most cases there's no reason to risk lives working on a live tether. There's still Jupiter's magnetosphere to worry about and the radiation it carries, but I think it would still be possible to use short range shell jamming for that (using optical laser communications or some other medium that is less interrupted by Jupiter's magnetosphere). The engineers could sit in a radiation-shielded ship or habitat near the tether and have the shells do the hands-on work. The Io Flux Tube, of course, is more dangerous than typical tether operations because of the large amount of ionized plasma. And since I imagine that's where the Jovian Republic would keep its antimatter factories, repairs out there are probably extremely skilled, very militarized operations.
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"It's a poor sort of memory that only works backwards." --The White Queen, [i]Through The Looking-Glass[/i] [img]https://lh6.googleusercontent.com/_zGgz13n3uzE/TWWPdvGig-I/AAAAAAAACI8/y...
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