|
|
Post by Enderminion on Aug 31, 2017 22:18:36 GMT
Another advantage for Titan: launching from the surface can use an air-breathing first stage, for example a spaceplane. It could be much simpler than one for Earth with the low gravity but high pressure, and the lower orbital speed to reach. Even if there is no oxygen for burning, and only a few percent of methane to use with on-board oxidizer, it can still use it as reaction mass. Or use a solid core nuclear turbo/ram/scramjet |
|
|
|
Post by matterbeam on Sept 1, 2017 0:11:21 GMT
ironclad6: I'd like to point out that the hydrocarbons from Titan are best used as feedstock for plastics, fertilizer and carbon-based material production. Your setting, as per the Fusion ship thread, seems to have easy fusion technology. It would make Saturn a fuel source for He3 and the development of the colony would not depend on a laser beam transmission network, but simpler shipments of fusion fuel to the moons. With fusion, you won't need wind farms on Titan! Enderminion: As I mentioned, fusion changes a lot of things. It would make colonizing Saturn much easier and put it on an equal footing with Jupiter. However, fusion means cheap and rapid transport. Saturn would have less value as a source of resources that could be obtained from asteroids. The biggest challenge for asteroid mining is the vast distances and travel times involved with transporting anything between them. Planetary systems like Jupiter or Saturn concentrate their minerals and metals in moons, effectively cutting down the deltaV cost of operations to that of inter-moon trajectories. With fusion, the asteroid travel times become much smaller and the comparison between a bunch of metallic asteroids and a moon becomes much tougher. thorneel: The lowest kj/mol cost of obtaining oxygen on Titan is splitting it from water. Reacting the oxygen with methane gives you back less energy and Isp than simply recombining it with the hydrogen you now have. Therefore, LH2/LOX rockets are most economical. Air-augmented rockets work great in the thick atmosphere, and launching from balloons or high-flying aircraft gives a substantial boost. Atmospheric methane is a very low percentage of Titan's atmospheric gasses, becoming a trace gas in the upper atmosphere. Another advantage is that inflatable structures become very practical. You can create launch towers that extend dozens of kilometers from the surface. Inside these towers, you can create a track that works like a railgun, or simple a trolley with a line feeding rocket fuel to the rocket until it clears the tower.
|
|
|
|
Post by ironclad6 on Sept 1, 2017 1:17:14 GMT
matterbeamInteresting. In which case, Titan can still be an industrial hub. If I'm not building my ships out of metals but rather carbons and so on then the lack of heavy elements doesn't seem to be a problem. You're right to point out the seemingly easy availability of fusion in my setting, however there are two things I'd comment on. First, it's never a good idea to be dependent on a single source of anything you really need. The second is that extrapolating from the use of magnetic confinement fusion onboard expensive, first rate warships to saying "All power comes from fusion" is a bit like looking at the US Navy in the eighties and nineties and saying "Look at all of those nuclear powered cruisers, submarines and aircraft carriers. I bet they get all of their power from nuclear fission". The military is high tech, high cost and high energy density. I don't think civilian or commercial entities would be so replete with energy sources that they'd turn down convenient and relatively abundant power that you don't a doctor of engineering to run. Also, your wind farms are pretty so I like them. That said, you're right. The shipyards on Iapetus almost certainly run on fusion bottles. The colonies on Titan supplying them with man power and raw materials probably don't. I'm also wondering about your opinion on one of the big economic motors of my setting, namely the terraforming of Mars (Mostly Mars, there are a couple of other worlds in the running but Mars is the closest and the work has been ongoing there for a couple of hundred years.) I'm using tugs to boost big chunks of ice out of Saturn's rings into the inner solar system. Once there, these ice blocks are scooped up by inner system tugs and de-orbited onto Mars. Is this idea just totally mental or do you think it's plausible (I've worked out how to provide for an electromagnetic field on Mars so that asmospheric gasses don't simply get stripped away by the Solar Wind but I don't really want to dwell on the Martian end of the thread while we're in a Saturn thread)
|
|
|
|
Post by apophys on Sept 4, 2017 4:26:17 GMT
I'm using tugs to boost big chunks of ice out of Saturn's rings into the inner solar system. Once there, these ice blocks are scooped up by inner system tugs and de-orbited onto Mars. Is this idea just totally mental or do you think it's plausible (I've worked out how to provide for an electromagnetic field on Mars so that asmospheric gasses don't simply get stripped away by the Solar Wind but I don't really want to dwell on the Martian end of the thread while we're in a Saturn thread) Mandatory viewing: I'm of the opinion that paving Mars with greenhouses makes the most sense in the short term, and eventually (in the extreme long term) deconstructing the planet for raw material. If you don't mind very long waiting times, comets should take less dV to move due to their highly elliptical orbits. |
|
|
|
Post by ironclad6 on Sept 4, 2017 19:08:07 GMT
I'm using tugs to boost big chunks of ice out of Saturn's rings into the inner solar system. Once there, these ice blocks are scooped up by inner system tugs and de-orbited onto Mars. Is this idea just totally mental or do you think it's plausible (I've worked out how to provide for an electromagnetic field on Mars so that asmospheric gasses don't simply get stripped away by the Solar Wind but I don't really want to dwell on the Martian end of the thread while we're in a Saturn thread) Mandatory viewing: I'm of the opinion that paving Mars with greenhouses makes the most sense in the short term, and eventually (in the extreme long term) deconstructing the planet for raw material. If you don't mind very long waiting times, comets should take less dV to move due to their highly elliptical orbits. Absolutely fascinating. I do wonder though about the idea of dismantling Mars. That seems...extreme. |
|
|
|
Post by bigbombr on Sept 4, 2017 19:52:05 GMT
Absolutely fascinating. I do wonder though about the idea of dismantling Mars. That seems...extreme. Indeed. Isaac Arthur once calculated that for a full Dyson sphere, you'd need to dismantle less than 1% of Mercury (though you'd probably just use asteroids, as that mass isn't trapped inside a gravity well). But if you want to colonise the entire Milky Way? Sure, why not disassemble your planets? (And asteroids. And comets. And star.) |
|
