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Spacescifi

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  1. Wow. The more I learn the stark realities of rocketry the more absurd using rocketry in space opera or soft scifi seems. No matter fission, fusion, or antimatter, the propellant challenge will bite you in the butt. Only the hardest of hard scifi stories can really do the realities of rocketry justice. As it is, even if I had an LH tank, refueling the easy way would involve extracting water from a moon or asteroid. Which is nontrivial since that implies I also launched a large empty tank along with my LH tank into space. And weight we know is the main reason we rely on staging our launches. Just launching a big spaceship in one go reduces the payload siginificantly as most all the weight will need to be propellant just to launch the rest of the propellant. Not to say I can't make scifi with rocketry, but when I do not ignore how rocketry works, which is virtually similar no matter if antimatter or solid propellant, it is story and plot breaking. One cannot expect a bunch of diverse missions for ONE explorer vessel. If anything rocketry favors sending out mulitiple explorer vessels, each with a specific mission, since launching and refueling are hardly trivial. For example, as kerbiloid mentioned it takes power to split hydrogen from water. What he did not mention was the time it will take. Depending on how much LH we were filling up and how powerful our nuclear or other reactor is at powering the process, it can easily take several hours at least, while several days is even more possible. So while it is theoretically possible to use warp induced gravity assists to change travel vectors and velocities, and it is possible to to refuel propellant, neither is conveinient for human space travel since they both involve waiting and waiting costs food resources. In fact, the only way a large human or humanoid presence in space seems justified is if the travel times can be reduced by a lot. I just do not see many signing up for missions that they know a robot could do better. In other words, Star Trek would make a lot more sense if robot ships did the exploring, and humans on ships came later. Because let's face it, the only things humans can really interact with is an Earth environment. If it's not that then you may as well send robots UNTIL you have made an outpost both suitable and comfortable for an extended human stay.
  2. Don't need to. The easiet way to tell is by talking to a chatbot. Not the brightest entity to speak with by any margin. Your pet dog cannot speak, but he or she STILL has far more reasonsing capacity than chatbot programming spitting out repetitions. Dogs actually have goals. Short-sighted perhaps, but they have them. Chatbots? No. Other than provide google extra info on users for ads and marketing.
  3. #%@^%! Yeah... I feel like that in my frustration, but thanks for adding some clarity to the scenario. I guess it turns out that using chemical rocketry on it's own is not very practical for refueling, since you NEED very specific fuels AND you have to refine them Best bets are in this order: 1. Some variation of nuclear thermal... no pesky LOX required. Since cleaning harvested fuel for a an LOX tank would require painstaking efforts to avoid combustion when it finally goes in the tank. 2. Some variation of fusion. It can be pulsed fusion, since that is a lot more possible and practical than having a sustained mini star onboard while trying to shed constant waste heat. 3. Some variation of antimatter thermal. And constant acceleration I think is overrated. Super high pulsed TWR is easier and better I think. Just launch everything up without the crew, and send crew to dock in orbit later. Crew ships will be slow by necessity, but prep need not be. With super high pulsed TWR with bo crew, we could have robots build a base so it will be ready abd waiting when the slow humans DO show up on Mars or the Moon.
  4. I think the answer is both yes and no. Example: Say your rocketship launches with methalox, and you find some ice in space and refuel with LH and LOX. I think you can use the same tank, just move what's left of remaining methalox to a holding tank, and put the fresh LH/LOX in the main tank. I know some chemicals react badly so you don't want to put new ones in a tank that has vapors of another gas. Corrosives are also to be avoided. But at least in some combos, the overall concept can work. What do you think? EDIT: I know chemicals have separate tanks before mixing to burn. What I am asking is if you can put a different chemical in a tank after pumping reserve chemical out. Their may still be vapor of the last chemical but nothing more. My guess? ONLY put oxygen with oxygen, and the more inert liquid gases we can probably reuse the same tank for without serious issues.
  5. So the instructions are easy. 1. Make up a title for a movie with a rating. 2. The next user says what movie would be about, the rating, and any other details they wish, like the director, and whether the movie would fail or suceed wildly at theatres. Since I am starting this I must make a movie: Batman VS Gandhi Plot in brief: Batman views Gandhi as the leader of a nationalist movement, with suspected ties to Ra's Al Ghul. Presents a saintlike image and is widely respected, but Bruce has a nightmare dream of him as a totalitarian monster nuking entire civilizations on a whim. Like this: Batman easily triumphs on a physical level, and maybe learns an important lesson on picking fights and prejudice, as this 'brutal warlord's' people rush to tend to their vanquished ruler even after being told they are free by Batman. Rating: PG-13 for obvious reasons. Should make a lot of money because of Batman being more absurd than usual. Zack Snyder is the director, because he's already done something similar Batman vs. Gandhi, would you go and see it? Title of next movie for the user below to describe: The History Of American Fried Chicken Rated PG-13
  6. Right. Assuming there is no water and you just want to mine metals, an airless low gravity moon or planet is a good choice. Yet refueling is the problem. So if there is no easy way IRL, we could just deal with it. If we have warp ability, we just carry enough propellant and resources for a single mission and return home at warp. Which means every mission is a round trip home. To refuel and restock, even though they carry enough to do the landing and relaunch off the destination. Because warp alone won't match velocity with landing spots, unless you warped repeatedly and dropped out for gravity assist, which still requires propellant for landing. So unlike Star Trek, we outfit for one mission and warp back home. Outfit, do it again. Can't just go hop from planet to planet since refueling is such an issue.
  7. I would argue that the main value of using dirt, whatever it's composition, is that it is far more plentiful than anything else. Ice is great, but it is not as common as dirt is in space. Not every planet even has H2O ice, although they may have CO2 ice. The advantage of dirty drives is that you can literally refuel anywhere. I guess the biggest change is that ships would have to refine the dirt into it's liquid components and use that as as propellant. Or refine the dirt into a powder for the solid rocket, which would be probably harder than just extracting chemicals from it for propellant.
  8. Good points, so I would have to compress the dirt before shoving it in the propellant tank. So drop it in the compressor filled. Problem solved? I wish lol. Well. Did not know rocketry was so hard. Copious amounts of stored antimatter still requires a fuel processor of propellant if you ever want good thrust once initial fuel runs out. Other solution: Use an antimatter powered laser to burn the dirt out the nozzle to provide thrust. Has waste heat issues but the idea is workable in principle. Could use dirt as a heat sink and shoot it out the nozzle.
  9. Heating up the air enough is an issue, a non trivial issue. In theory you could launch Elon's StarshipX with an antimatter thermal air rocket.... assuming we did not melt the engine trying. More heat/energy required to provide the momentum transfer for stuff that weighs less (air). Dirt would require less AM thermal energy for thrust, since the mass flow will be higher. As for diverse solid propellant,I do not see at as a problem because there are solutions. Send a probe down first to sample the soil. Good? Okay, land the whole ship and use chemical engines to slow for landing. Then refuel dirt propellant and chemical if possible. Launch again. Chemical propellant can be pulse or constant. Whereas solid propellant burns constant till it runs out. Thus the use of chemical propellant for landings. It is a good idea to have at least two engines on an explorer. One for powerful for launch, and another for orbital maneuvering. In my example, chemical engines do double duty as orbital and landing engines. As for numbers.... not my strong suite.
  10. You suppose I have not already thought of the other implicatiions? Easy antimatter production also means efficient storage and failsafes otherwise crews would never use it. Dirt propellant is the difference between using just air and AM, which may not provide enough thrust. Mixing tech levels? If I wanted to make explorer spaceships that can land,, refuel, and relaunch, this is the quickest solution I can think up.
  11. If antimatter ever becomes more efficiently produced, would not dirt as propellant be sufficient to reach the Karman line and then use chemical rockets for orbital insertion? The catch is that we are igniting the dirt with a liberal amount of antimatter. The whole reason for this idea is cheap and easy refueling. Just land, take out the tractor. Scoop. Dump. Liftoff! Of course it's going to be bunch of ashy black exhaust but that's the price we pay. Liquid propellant is best used for spqce anyway where efficiency matters most. What do you think? Take the size and mass of starshipX (Elon's) as a rough estimate to calculate from. Could dirt and antimatter be enough to loft it into space? Not orbit, as the chemical AM thermal enginea do that. On the moon it seems VERY viable. Earth I can only hope so.
  12. A fusion torch itself is a thorn I believe. How you gonna cool it? The more heatsinks you put on you lower overall thrust, unless you start feeding THAT as reaction mass, which means your dead after you exhaust them all. Radiators need to huge, and in atmosphere that's a bad idea. So honestly,I hate to say it, but if scifi writers wanba go hard with gas giant refueling, you need some kind project Orion/rocket SSTO hybrid that scoop the gas as it does reentry. The orion pusher plate will provide tge thrust to retutn to space, while rockets will alliw for safe initial launch and landing.
  13. Not sure I can handle this. I still have PTSD from playing 3-D asteroids. Like it's so bad that even if you gave me a scifi spaceship for free but told me the controls are ONLY manual... I would likely turn it down. Which is sad. I mean that game is ridicuously manual. It's like they put all the RCS on max thrust so that ever push you overcompensate for and have to correct.
  14. Very nice. Now I wanna see a solid booster transparent. Or what I really want is a reusuable bipropellant solid/chemical booster. Best of both worlds!
  15. I do appreciate when you call out an idea that would be lethal. Usually happens when I try to use real science, for I have little need for science when I make up everything on the fly. So thank you. I really thought I had a good thing going with the magnetic field, but did not take into account the g-force from air impact. It's ironic really, since for all the slowing when astronauts come down dyring reentry they are pulled back into their seats, not pulled forward, right? Since the air is slowing gradually as they continue to fall along a curve. But if they took a steep or head on dive... yeah... that's braking on steroids and fiery death. As for making stuff up, I do think it is fine considering implications so long they have an effect on how things hapoen in the story. All the contrivance in the world of a fictional device is an absolute waste of tge reader's time if it does not have some or a lot of bearing in the plot. In my opinion. I am not someone who thinks knowing the A to Z of a fictional empire is something that needs the reader's attention. Unless it bears on the events that happen in the story. Otherwise do not do that. Or at least I won't in my SF.
  16. Orbital weapons are mainly good for attacking incoming space fleets from other planets... which is a very dated idea by the way to assume aliens far more advanced than us would be vulnerable to our weapons in space at all, let alone even needing to do more than fly past and through weapon satelites without us ever knowing, laughing as they do.
  17. I see.... well you make interesting points. Namely that the point I put an idea to paper it is either beyond anything we know how to do or will require answers to questions we have not even asked in earnest yet. Thus using fiction is totally justifiable and I tend to agree. I am aware that doing scifi stuff by it's very definition will allow all sorts of stuff I cannot even imagine. Namely warping of space vacuum according to current science requires on paper negative matter... which only exists on paper that we know of. And dark energy is so mysterious that we literally call it that because we assume it must be a force we just are not aware of. At any rate I think the key to ALL scifi tech lies in small manipulation rather than big. The better one is at sewing the better garment they can make, rather than tying knots and calling it good. Interestingly, a single fish is far more a conplex creature than a star, which is just a bunch of mass inducing a fusion reaction. I do not know the future tech at all, but I take ideas I wish we had that I like and incorporate them.
  18. Well that is why the tech must be futuristic. Interestingly.... liquid magnets are possible to make, and may allow for much stronger magnets that won't break. https://www.google.com/amp/s/www.sciencealert.com/scientists-have-printed-droplets-of-permanently-magnetic-liquid-and-boy-is-it-trippy/amp If we ever make electromagnetic fluids we can switch the field on or off that will be a game changer.
  19. Well deceleration does make sense. The one thing I had not considered. I am not sure which is better, shooting rockets out of cannons for orbital insertion burns once they hit vacuum, or magnetic vacuum tube acceleration. Likely the cannons are easier to make. It's actually not a bad idea at all. Make an array of launch cannons, firing cone shaped tungsten nose rockets into space. Once an insertion burn is performed the craft can circle in orbit while crew only is sent up to rendezvous in rockets. Everything else can be launched via cannon. That's actually a feasible starfleet orbital cobstruction program. Even easier if you mount the cannons off a mountain. A mix of nuclear and or chemical power is all you need to power the cannon to pull this off. EDIT: Diamagnetic field is still good for reentry so long ship has internal heat sinks (LH tanks suffice).
  20. Yes but the risk does not justify it. I don't know about in KSP, but IRL a mere wind gust can be the difference between docking and colliding. And it's not as if they are planes and get plenty of retries to dock. Rockets stay in the air only a shot while before they reach space. Margin for error is lower than normal launch. That's why they don't do it. Try it in KSP.
  21. This is definitely a futuristic discussion, as the energy required to make magnetism diamagnetic is not trivial. Yet the principle is sound... at least I think so. Step 1: Send a rocket down a magnetic vacuum tube and accelerate it fast enough that it will reach space upon release only needing to do an orbital insertion burn to reach orbital speed. Usual Problem Solved: Normally a ship would be obliterated from impacting the air at that speed. Solution? Diamagnetism. A magnetic forward hull so powerful that it literally blocks air and plasma from touching it. What happens? Upon leaving the tube you likely see a ball of fire, as with railguns, but the ship will come out so fast all you will see is a small fireball in the distance as it ascends into the sky. Reentry: Also solved. Thr heating problem: Can be solved with internal heat sinks, since powerful magnets generate heat, so being a bulky vessel helps here. Granted it may not be an SSTO, but at least it can land in one piece if it had to. Bonus landing: If you can make the ship belly diamagnetic as well you could hover over the ocean, or even do a hovering ocean landing, using the water compression against the belly magnetic field to slow you down like a virtual runway. What do you think?
  22. Casualties in space should also be low or none, given that robot ships can do most of the fighting. All crew are to an enemy is hostages. And the whole objective of the war, if merely to take territory, whether a space station or a resource outpost on a planet, involves not blasting whar you want to bits. If you do that, it's just a button pushing affair and sooner or later the bombs will be coming for ya. To be honest I find wars of annihilation to be... kind of cliche. Like IRL wars of annihilation are often because religions or ethnic hatred, which is rarely the case in popular scifi since religion is like supposed to not be around or is ignored or something (B5 is an exception even though they scified by saying it was aliens all along). What I am saying is that going on extermination mode simply fir territory is a rather extreme act to take, and should be far less popular than it is in scifi, at least if going for realism. Ignore or have zero rules of engagement and sooner or later everyone will take you down. Don't believe me? Look what happened to the Assyrians. After a costly civil war they were ganked by their many enemies. End of empire.
  23. I think perhaps posters are sidetracked. The rules are not for your creations. The rules are ones that YOU as the creator will not have the power to break unless you wipe the slate clean of all you made with your handy dandy universal eraser. By the way... as fascinating a concept as it is, if anyone offers a human godlike powers, the safer option is to simply refuse. Played a video game where the character fought battles, solved puzzles and mazes, all to get some all powerful macguffin, only to reject when he understood it's true power. It did not give the player the choice to choose to accept the offer. Which sounds about right. It was a star trek game, and it is not Trekkian (at least the TNG abd DS9 era not the abomination of Picard) to accept godlike powers so as to take over the rest of the Alpha Quadrant. Which I was partial to doing. Random ships attacking you the whole game forcing you to make repairs kind of makes ya vindictive after a while.
  24. Logistics? You mean how efficiently they can transport supplies for tge war effort? I suppose. The only real counter to that is pure numbers, which because of the high orbital plus speeds involved, usually means that all out offense is both the best defense and offense. The closest thing to a defense is faking high value targets with hollow ships with engines and padding only. Or even better... shield ships. Ships full of water that can take a beating and even reseal the hull breaches with ice spray. EDIT: Full quote by Tzu: "All warfare is based on deception. Hence, when we are able to attack, we must seem unable; when using our forces, we must appear inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near." Sun tzu, The Art of War Tags: deception, strategy, tactics Too bad scifi villains are idiots too often. Never read Tzu.
  25. Are you talking about the recent radioactive disaster involving several deaths and a missile of theirs? Perhaps. Even so, do you not think we can do better with current tech? Lighter, faster, harder?
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