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Terwin

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  1. This is less a suit and more a small pod with arm and leg waldos. Not sure if you can pull your legs into the pod, but clearly you can pull your arms into the pod for operating controls or the like.
  2. For a chemical rocket, the larger the better. The fuel mas increases based on volume, and tank mass only increases based on area, giving a higher fuel fraction the larger you go. While available thrust is also limited based on area, you can always go with a wider diameter to mitigate this. Side-mounted boosters are also a good way to increase thrust-area, even if they may not have as much of a benefit as increasing the diameter. (Falcon heavy shows a good example of this) I am pretty sure that the only reason to have a first stage the burns out within a few hundred feet of the launchpad is if you are limited to pre-existing rocket parts assembled in a lego fashion(like KSP) and your vessel is on a much larger scale than the parts. While w have not yet figured out how to make engines larger than a specific size(thus limiting per-engine output), SpaceX is a good example of using lots of reliable engines in tandem for huge thrust. There may come a point where engine reliability limits your ability to increase the TWR of the engine section of a given stage, but increasing engine reliability can push that point out to ridiculous extremes. No, if you want a pulsed fusion powered engine, you want to make every pulse relatively small(as in grams of TNT equivalent per pulse per engine), so that you can have chamber walls of a reasonable thickness and thus a reasonable twr.
  3. In the release version, you need to have specific transport containers to count for vessel transport capacity.
  4. Compared to a pure-fusion Orion as advocated by that article, a fission Orion is likely a better choice, as it is much simpler. On the other hand, the article was advocating for a deep-space fusion Orion because it could refuel from ice or any other hydrogen source. Should the technical hurdles be over-come, there is the argument to be made that a pure-fusion Orion would be superior to a fission Orion with regards to ISRU. On the other hand, compared to a more realistic use of fusion for propulsion(mini-mag, fusion torch, micro-pulses, etc.) any form of Orion is the lesser choice. A 50g fusion pellet will not have the same out-put as a 100lb fission bomb. Then again, a 100lb fission bomb weighs more than 900 50g pellets, so even if the pellet has two orders of magnitude less impulse, it may still have a higher isp. To the best of my understanding, we have not yet successfully demonstrated a sustained reaction in a tokamak style reactor, but we have demonstrated fusion pulses(NIF). While it would be an awful design, we could theoretically put a NIF style ignition, powered by an on-board fission reactor, to super-heat the reaction mass for a deep space(low-thrust, high ISP) vessel. This would not require anything we cannot do today, so I would argue that a fusion micro-pulse propelled spacecraft is possible with today's technology, but a continuous fusion torch is not yet in our grasp.
  5. Sort of replacing the combustion of a chemical rocket with little bits of fusion? If you have sufficiently rapid small-scale fusion events, that sounds a bit like a fuel-rich fusion torch set-up when running. When using an actively cooled chamber/nozzle, I do not think that the heat is the greatest problem, but the pressure-wave caused by the fusion blast would very much be a limiting factor, as the stronger the blast, the thicker everything needs to be to contain it without popping like an over-filled balloon. Ablative cooling works, so long as you have ablative left, but it does not help much against pressure waves. I think pressure waves would be a bigger issue than straight-up heating.
  6. Fission does not scale down below critical mass, while fusion can scale all the way down to 17.6 MeV (2.8 x 10^-12 joules). The only reason to use a pusher-plate is if you have no materials that can contain/redirect the blast out of a nozzle. As a thin layer of balsa-wood is plenty strong enough to contain the 'blast' from a single pair of hydrogens fusing into a helium, you would need some serious handwavium going on for a fusion powered pusher-plate vessel to make any sense. Because anything less than 42 gigajoules(10 tons of TNT, aka smallest fission bomb yield and roughly 2x10^13 times the size of the smallest workable fusion yield) will attract the giant space-beavers that will eat your crew-cabin, then use the rest of the rocket to build their space-dams.
  7. Why? This gives you all the complexity of pure fusion(which can scale down to single fusion events) with the scaling problems of fission(minimum impulse size limited by critical mass). Instead of a single large impulse every X seconds, do 100 impulses of 1% of the large impulse at a rate of 100 per x seconds. This lets you reduce the strength of just about everything involved by at least two orders of magnitude, greatly reducing engine weight and improving TWR. Take this to the logical extreme and you have a drive that is either continuous or has very small discrete fuel 'pellets' igniting many times per second. Also, with fusion, you do not need pre-packaged pure-fusion bombs, but can instead use the same ignition source and just pump in the hydrogen you want to ignite(possibly in a magnetic bottle or some such). Why would this form of engine create mushroom clouds when other engines that also shoot out super-hot gas do not? There is no huge fireball to ascend into the sky and provide that mushroom shape(unless something goes very wrong, and at that point your ship is no longer reusable). With fusion, you do not want discrete bombs, you have a single reusable means of igniting the fusion that you use either continuously for a torch drive, or for small discrete packages of fuel for a pulse drive. Ideally, your fuel is a large tank of hydrogen that you can refuel anywhere with easily accessible hydrogen.
  8. Also, all of that extra detail is something that should only even exist if it will be a significant plot point. With science fiction, the needs of the story drive everything else. Everyone needs air to live, but how often does a story mention a character breathing? Only when it illustrates or extends something directly important for the story, the rest of the time, it is a useless side-bar that usually detracts from the story as a whole. If pusher-plates come up as a critical dramatic point in the story, then you have pusher-plates, even if they make no technical sense. If they do not serve as a critical dramatic point, then the reader should be completely ignorant of those drive details. If the story requires that an apollo stack can get to alpha centari in less than 5 years, then it can. If the story does not come first, then nothing else matters because no one will read it.
  9. Orion only works in atmosphere if you are ok with melting the whole thing and irradiating your cargo while you do so. (Atmosphere can reflect both heat and radiation, space not so much. This is not even considering the atmospheric shock-waves) All of the hardest parts of fusion rocketry are also required for a pure fusion orion. If anything they are made harder by having more space and an extended pusher-plate between the ignition sources and the ignition target. Fission is generally safer then fission, yes, but you may still have more radiation because your nuclear reaction is not inside of any sort of containment vessel.
  10. I was referring to liftoff, but an atmospheric retro-burn would likely be at least as bad, especially once you get sub-sonic.
  11. And this is why you cannot launch using ORION: anything strong enough to get it off the ground will melt your ship to slag. A pusher-plate will *not* shield you from atmospheric heating.
  12. They are in the save file. But it does not save modules, just the effects of the modules. So you will need to manually reverse the effect of any modules you want to 'remove'
  13. 5th percentile female is 4'11" 95th percentile male is 6'2" Just another place that being a statistical outlier is annoying (6'6")
  14. General relativity says that there is no absolute frame of reference. Everything is only relative to a specific point of observation. I had a physics professor that claimed he would define his house as the center of the universe. It may make some of the math more complicated, but it all works out. It is also just as technically valid as any other possible 'center-point'. That is also how you define an immovable object: that object is your reference point, so no matter if it is closer to Earth or Jupiter, it is still your origin point, and thus, by definition it has not moved.(but the math on the rest of the universe may get a bit complicated if a force is being applied to your immovable object...)
  15. Due to expansion, this would allow multiple objects that are at 'absolute rest' even though they are traveling at close to C relative to each other if they are far enough apart.
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