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Post by Enderminion on Oct 22, 2017 21:02:23 GMT -6
a 1950s era USAF Space Battleship to be armed with 200 20Mt city killing warheads and low hundreds of casaba howitzer tactical orbit to surface weapons, defense weapons include 3 5" naval guns and CIWS type autocannons, a nightmere for defense planners as the warships can wait in lunar orbit and move in after the first strikes and decimate the enemy. a fiction story I read had Typhoon class submarines with anti-orbital missiles in the SLBM silos as a defense aganist them as well as orbital nuclear mines to blind sensors. Atomic Rockets Link |
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Post by Airy W on Nov 1, 2017 12:35:18 GMT -6
Atomic Rockets are the guys who say that stealth is impossible in space, no way, no how, it's just engineering you noob. They also gave a seal of approval to this guy: seen here suggesting a rocket design that combines fuel types. Not on two different stages mind you, on the same stage. Put LOX/LCH4 engines next to LOX/RP1 engines. To make development simpler! That is, to put it mildly, not a very wise idea and unlikely to simplify development. But it's on a site with the atomic rockets seal of approval. I actually have a point here, besides just trashing on Atomic Rockets for having poor judgement. That point is that often in "realistic" science fiction, people underestimate the number of small technical challenge to do something. They reduce the matter down to just mere physics. But if it was just mere physics, we would have been on the moon in the 1930s, that's when we had the fuel and materials to solve the physics cheaply. The main problems in doing this sci-fi stuff aren't physics, they are engineering. Every vehicle has it's own particular mistakes, it's own versions of putting LH2 and RP1 on the same stage. These are things that are theoretically possible but can go wrong. And they degrade performance. If you look at the space shuttle, you can see this. In theory, putting the space shuttle on the side of the tank shouldn't have hurt performance very much. The drag would be a bit higher but that wouldn't reduce payload a lot. But the actual performance loss came from heat shield damage that happened when ice fell off the tank (which was hundreds of degrees below freezing) and hit the heat shield.. Now you might think that is a safety problem not a performance problem. But because of that heat shield damage, the heat shields had to be redesigned for redundancy and insulation had to be added to the fuel tank. Those things reduced performance. So as a result the space shuttle payload was reduced below what it was supposed to be. There were many other such complications but that one is particularly well known. Subsequent reusable vehicle designs have returned to the idea of staged rockets, with different engines for the first and second stages. It turns out that theoretical improvements are less important then tangible results. To bring all of this to a point, when you see an idea like that, dont think it's realistic based on the things that they talk about. Ask yourself if it's realistic based on the things they aren't seeing. What are the complications there that they dont have a solid grasp of? The physics of the Orion project check out. But the engineering? That's highly speculative. And the heavy launchers that were necessary to make it work weren't practical at the time. The next generations of heavy lifters could manage it but they are based on a different philosophy, instead of using futuristic concepts to avoid sending up hydrogen, just find a more cost effective way to send up hydrogen. |
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Post by Enderminion on Nov 1, 2017 12:50:11 GMT -6
heavy launchers? the Orion drive is best at taking off from planets, yes that involves detonating ~200 sub kiloton nukes but what's a little bit of fallout gonna do? also I happen to know nvm they found this post, He has good ideas that are impractical, mixing LOX/LCH4 and LOX/LC12H26 engines is a rather poor idea
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Post by director on Jan 21, 2018 23:02:02 GMT -6
I got into SevenEves by Neal Stephenson and was enjoying it up until this happened: the Earth will be destroyed, we need to get everybody off RIGHT NOW and environmental damage does not matter, and nobody even thought of Orion.
In the words of (attributed to) Dorothy Parker: "This is not a novel to be tossed aside lightly. It should be thrown with great force." And I did.
Orion would be great for achieving really high cruising speeds - you could get to Mars or out to Jupiter pretty quickly. If you had a way to ignite fusion bombs with lasers (or some method not involving fission bombs) then you could run it pretty much constantly. But for getting really big payloads off of the Earth's surface it is really attractive - as long as you don't care about the fallout.
For a fictional version done well, check out Niven and Pournelle's "Footfall" or Poul Anderson's "Orion Shall Rise".
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