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Post by srbrant on Oct 20, 2017 5:48:42 GMT
Here's a kind of ship for my novel Kemono that I've been struggling with a bit. A true mothership: a cruise liner, a tugboat and an oil tanker in one in nautical terms. It's a massive spacecraft that refuels the ships docked to it in addition to carrying them through hyperspace (I need to find a better word for that.) The personnel in the docked ships make their way inside and mingle within its internal habitat, corridors and rooms snaking around gigantic tanks of reaction mass. I named it after the Heighliners of Dune and Robert Heinlein to create...
THE HEINLEINER.
But here's where there's a problem and it's an obvious one: the sheer mass of the thing. It's meant to tow up to six (or even more) smaller ships between one and twenty-five kilotons and although the setting's technological level allows for drastically increased Delta-V and fuel efficiency, there's still the issue of how adding more reaction mass gives it less and less acceleration time because of the increase in mass. And even without the mass issue, there's how to prevent interreflection when you have two ships docked right together.
The reason these things exist in the story is to come to the rescue of ships that have run out of reaction mass or to act as a base of operations around worlds with little or no infrastructure. And if you can't find a fueling station or a colony within reach, you may have to send out a distress signal...which is the equivalent of shouting "I'm rich and defenseless" in the middle of Chicago.
Thoughts?
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Post by RiftandRend on Oct 20, 2017 7:45:46 GMT
Hyperspace Actual discussion of physics Pick one. In all seriousness, if you can generate some kind of warp field/wormhole/ without having energy beamed to you you are using antimatter or micro-black holes for power. If you have that, you can make engines that are absurdly powerful and efficient, making acceleration and Delta-V minor issues.
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Post by jtyotjotjipaefvj on Oct 20, 2017 12:10:40 GMT
Hyperspace Actual discussion of physics Pick one. In all seriousness, if you can generate some kind of warp field/wormhole/ without having energy beamed to you you are using antimatter or micro-black holes for power. If you have that, you can make engines that are absurdly powerful and efficient, making acceleration and Delta-V minor issues. Although if we're writing fiction and not a technical report, we can pick and choose details that make for interesting stories instead of focusing on every last detail of what would happen in the real world. Not all scifi needs to be autistically hard, even though it's nice to read those kinds of books now and then too.
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Post by Kerr on Oct 20, 2017 12:45:32 GMT
Hyperspace Actual discussion of physics Pick one. In all seriousness, if you can generate some kind of warp field/wormhole/ without having energy beamed to you you are using antimatter or micro-black holes for power. If you have that, you can make engines that are absurdly powerful and efficient, making acceleration and Delta-V minor issues. Although if we're writing fiction and not a technical report, we can pick and choose details that make for interesting stories instead of focusing on every last detail of what would happen in the real world. Not all scifi needs to be autistically hard, even though it's nice to read those kinds of books now and then too. "...The stuff I'm working on is something that's realistic but at the same time and of equal measure something that will inspire engineers, physicists and scientists." -sbrant. I am pretty sure that he want's to make a (semi?)hard sci-fi story.
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Post by jtyotjotjipaefvj on Oct 20, 2017 13:15:26 GMT
Although if we're writing fiction and not a technical report, we can pick and choose details that make for interesting stories instead of focusing on every last detail of what would happen in the real world. Not all scifi needs to be autistically hard, even though it's nice to read those kinds of books now and then too. "...The stuff I'm working on is something that's realistic but at the same time and of equal measure something that will inspire engineers, physicists and scientists." -sbrant. I am pretty sure that he want's to make a (semi?)hard sci-fi story. Still, saying that just because you have hyperdrives you can't have limited resourcers is a bit silly. You can plausibly work around the issue by handwaving hyperdrive tech as using some method that doesn't require practically infinite amounts of energy unlike the current understanding of hyper drives. After that you can have fusion torches and hyperdrives in the same setting while remaining internally consistent.
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Post by srbrant on Oct 20, 2017 13:29:10 GMT
"...The stuff I'm working on is something that's realistic but at the same time and of equal measure something that will inspire engineers, physicists and scientists." -sbrant. I am pretty sure that he want's to make a (semi?)hard sci-fi story. Still, saying that just because you have hyperdrives you can't have limited resourcers is a bit silly. You can plausibly work around the issue by handwaving hyperdrive tech as using some method that doesn't require practically infinite amounts of energy unlike the current understanding of hyper drives. After that you can have fusion torches and hyperdrives in the same setting while remaining internally consistent. And as I've said before, MANY TIMES, the futuristic setting means that some liberties can be taken but just enough so that I don't become a war criminal against science.
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Post by Kerr on Oct 20, 2017 13:41:35 GMT
"...The stuff I'm working on is something that's realistic but at the same time and of equal measure something that will inspire engineers, physicists and scientists." -sbrant. I am pretty sure that he want's to make a (semi?)hard sci-fi story. Still, saying that just because you have hyperdrives you can't have limited resourcers is a bit silly. You can plausibly work around the issue by handwaving hyperdrive tech as using some method that doesn't require practically infinite amounts of energy unlike the current understanding of hyper drives. After that you can have fusion torches and hyperdrives in the same setting while remaining internally consistent. The Hyperdrive energy consumption and limited ressources don't bother me that much, the Alcubierre drive is supposed to generate an 10c bubble with enough volume for the space shuttle with one voyager 1 worth of matter-antimatter. The main problem with hyperdrives is that they are superluminal, which mean they travel back in time ergo. create time paradoxes. Casuality, Relativity and FTL, pick two. Hyperdrives and limited ressources sounds like a janitor who uses a concorde to get to his working place. But whatever, use as many handwavium drives as you want. If sbrant wants to include hyperdrives he can do that, aslong as the story itself is good and he is happy with it.
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Post by Enderminion on Oct 20, 2017 14:50:16 GMT
wormholes cause *less* problems then hyperdrives, but then you can't use sailing metaphors as well
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Post by Kerr on Oct 20, 2017 15:35:43 GMT
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Post by srbrant on Oct 20, 2017 17:19:45 GMT
Look, enough with the FTL squabbling - let's talk about the main issue of this thing: mass.
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Post by Kerr on Oct 20, 2017 18:18:46 GMT
Look, enough with the FTL squabbling - let's talk about the main issue of this thing: mass. Alright, alright. Acceleration can be fixed by an bigger engine. The Delta-v problem could be solved by using an higher isp fuel if possible. If your main problem is carrying all that remass fuel around then there are 3 options. 1. Magnetic Scoops. Utilized by bussard ramjet and RAIR it uses an magnetic field to scoop ionized hydrogen from the interstellar medium. But even an 100t scoop needs to move at several percent of c until it gains useful amounts of fuel. You could use it in low sun orbit, where it can scoop several kilograms of hydrogen every second with minimal investments. 2. Atmospheric scoops. You could use atmospheres of gas giant or earth to get remass. This requires some spaceplanes which have some cryogenic equipment to produce LOX or liquid nitrogen. Both are fairly dense. Or use an creative way like this one toughsf.blogspot.de/2017/09/low-earth-orbit-atmospheric-scoops.html?m=1Made by matterbeam. 3. In-situ. You could also use special equipment on your ship to convert an asteroid into useful fuel. There are alot of icy asteroids in the asteroid belt. Which can give you enourmous amounts of hydrogen and oxygen which can be used as remass.
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Post by RiftandRend on Oct 20, 2017 18:50:43 GMT
Look, enough with the FTL squabbling - let's talk about the main issue of this thing: mass. If the mass of the ship is around 1-10 Mt, then regular NTRs would be enough to provide reasonable acceleration and Delta-V.
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Post by thorneel on Oct 20, 2017 20:39:59 GMT
What tech are your ships using? Arcjet? Antimatter-catalysed pulse fusion? Nuclear salt-water?
Also yeah, don't worry too much about FTL. Just check Atomic Rocket and craft one that has the least direct impact on the stories you want to tell. I have some affection for the Attack Vector: Tactical version of jump points very close to the star, personally.
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Post by srbrant on Oct 21, 2017 3:53:52 GMT
Look, enough with the FTL squabbling - let's talk about the main issue of this thing: mass. If the mass of the ship is around 1-10 Mt, then regular NTRs would be enough to provide reasonable acceleration and Delta-V. Ah, the ol' standard! Mass is also reduced a bit by some applied phlebetonium materials (plasteel, arachnite, etc), though their usefulness isn't too much of an improvement because they're used to make larger crew spaces.
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Post by srbrant on Oct 21, 2017 4:26:37 GMT
What tech are your ships using? Arcjet? Antimatter-catalysed pulse fusion? Nuclear salt-water? Also yeah, don't worry too much about FTL. Just check Atomic Rocket and craft one that has the least direct impact on the stories you want to tell. I have some affection for the Attack Vector: Tactical version of jump points very close to the star, personally. Fusion reactors. Hi-tech ones, but ultimately standard. Encased in a cage of boron carbide, lead and lithium-6 surrounding them for added protection (some maintenance corridors get pretty close there.) The "jump points" are simply Lagrange points. Some asteroids have been pushed into them and used as the beginnings of large space colonies...or pirate havens.
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