Spacescifi

Well I like linear wedge shaped shock intake. cones because then they match the linear wedge aerospikes. Plus it is is a bit of scifi that is actually a reachable goal to strive for... unlike FTL or warp which is more a necessary plot device.

You misunderstood it. I meant that if you translate within 100 kilometers of a planet... whether that means it's atmosphere OR in the case of having none, it's crust. Slight Edit: Really the drive is more practical for us if we forget trajectories and have ship point where it is translating. 100 kilometer lock radius is fine, since it is easy for a ship to travel 100k from a planet's atmosphere. If you mess up, you lose the main ship to translation, which is why warp staging (multiple detachable vessels with warp drives) is needed. Meaning you lose the big ship and start translating again. Can only do it so many times before ee run out of spare warp ships, and they get progressively smaller too. Matching planet speed after translation is nothing that an antimatter upgraded pusher plate orion with airbreathing nuclear aerospike SSTO shuttles could not handle. In other words, use the orion as as an orbit to orbit vessel. Use the airbreathing shuttles to ship payloads betwern the planet and the orion orbiter mothership.

We are firmly in fictional territory here. So the easiest thing to do is ignore it and just let all ships warp anyway. Now if I wanted to delve into the how's and why's of fantasy, it is utterly vain for me to do UNLESS it is a plot point or will be later. And if it was... even then a discerning reader could pick it apart, so why bother? I mean I could say the ship travels translates through a narrow tube of warped space that stretches 7 lightyears in each direction. And any ship making it's own would have to not cross tubed or cancel each other out. But realistically... probably would'nt be a plot point anyway... so a wast of time for me. Making stuff plausible is a fool's errand unless we have a possible idea of how to do it.

Yes... I knew of other antimatter schemes that are more efficient, variants of project Orion among them that combine high thrust with high efficiency of fuel (bombs). As for AM thermal rockets, like all rockets their main limit is running out of propellant, which leads to a lot of thrust and drift. Which is not exactly good for crew health, even if you have FTL or what have you. Somewhat off subject, but I discovered that if you had both fictional constant acceleration and warp or spatial translation, you would not need artificial gravity or spinning of the ship at all. See, if the ship is moving space without actually moving, if you engage your engines you go nowhere,but since you're moving through space that is moving, it is like you are running on a treadmill. You feel the workout (gravity) but you go nowhere. Until you drop out of warp. Neat little trick.

I see... so again reality proves those unwanted spaceship scuffles in orbit as pure fiction. If I don't want to be caught up with or be fighting with another spaceship in orbit and it has similar specs to mine... I won't. It is not a forced sitiation after all. Now launching suborbital craft or missiles to hit an orbiting craft actually could force the orbiter to run out of fuel, but that is another discussion.

So you are saying that because of the extra mass of heat exchangers and radiators required, antimatter rockets won't be greater by a large margin compared to nuclear? That would be funny: Captain 1: My ship runs on AM and propellant. Captain 2: Mine runs on nuclear and propellant. Let's race to the moon roundtrip to see who gets back to Earth first! I have a feeling the nuclear actually has a chance of winning, since unless the stuff required to store the AM is small or lightweight, it will probably be on par with a nuclear for weight or greater. Weight matters not in space, but weight means mass and mass does matter. Meaning more mass requires more thrust to change speed quickly. More thrust means you run out of propellant faster, which is the difference between a controlled landing and a crash landing, depending on how much you have. Or worse yet, missing the planet entirely with zero propellant.

How to chase and rendezvous with another spaceship in orbit? The most I learned first hand was playing a clone of the original 2-D Space War. I used the star in the middle to orbit, and I found orbiting head on toward my target was one of the fastest ways to intercept. In real life we do not have infinite fuel, so I was thinking... how does one chase down a spaceship in orbit that does not want to be caught up with? Provided both ship's have similar specifications? My guess? Try to fly as close to the planet as possible and then speed up to fly over and avoid diving into atmosphere. That will at least give you a gravity assisted boost to orbit faster. Go too deep and you eat atmosphere though, while also killing your speed. I guess this will result in a tie if both ships have the same specs, since they can evade each other forever until they run out of fuel. Playing dirty is another way by littering orbit with debris, but there is a fine line between destroying and disabling a spaceship.

Thank you. I thought so... just needed confirmation. I have found that real life science actually allows more variety for spaceship shapes than media scifi. Since media scifi vessels are more often than not inspired by fiction/fantasy rather than reality, so that limits the choices of shape to arbritrary choices that are only governed by the rule of cool. So in conclusion, I have learned that a proper SSTO can look several ways, and an SSTO with heavy payload is NOT an optimal aircraft... you wanna get that thing into orbit ASAP. So SW odd looking ships dog fighting like fighter airplanes is very much fiction, since to optimize for that a ship has to have the shape for it and preferably wings. Meanwhile if your vessel is mainly for space... why dogfight? Get to space already!

Namely... metal embittlement is a concern if you use hydrolox for your spaceship overtime, plus it has it's advantages simulated that we know, plus the disadvantages (huge tanks required). Methalox, RP1 etc... how hard would this be to simulate? It is doable is it not? It's a lot easier than trying to simulate damage per acceleration or speed (like in real life) which is why games typically rely on DPS overtime instead. What you think?

Alright... I will make it simple. EDIT: Forget the trajectory thing. Point starship's nose in the direction you want to translate and translate. While translating you go in a linear path, lightspeed or a lightyear per hour are your options. Unlike my first iteration, you will continue to translate forever UNLESS you come within 1 lightsecond radius of a celestial body (planets, stars, etc) with a gravity of 1g or greater. The other option is to abandon ship while it leaves you at luminal warp. Better? I like it. So once again warp engine staging seems to be the safest way to go, at least until a star system is mapped out. Inertial navigation can handle the rest once they have a map. Orbits are predictable. Answer regarding methane: What other propellant would you suggest? IRL hydrogen and oxygen is king since it requires less propellant for efficient thrust, but the massive fuel tankage and pipes required tend to negate that at liftoff because of gravity. Methane would require more propellant burned to get the same thrust that hydrogen and oxygen does, but it is easier to store than hydrogen. If you had a starfleet would you prefer less vessels using LH because it is difficult to handle, or more vessels using methane, which is easier to handle? I am not arguing. I only want suggestions. Elon seems to like methane. Would you suggest RP-1? Or better yet, just write 'Rocket propellant mix' without naming what is actually used and leave it to the reader to guess? Slight EDIT: A bimodal propellant mix seems to work best: was just wondering about Nuclear Methalox... Discussion Is this possible/worth it to use a (closed cycle) lox augmented nuclear methane engine for on-earth and off-earth missions? I know there would be political issues but how would it compare to nuclear hydrolox? Reddit answer: You see to be talking about nuclear engine with afterburners. These engines operate in two modes, one where the propellant is heated by the reactor and expanded through a nozzle (achieves high efficiency) and one where the hot propellant has oxygen injected to burn it and provide additional thrust (higher thrust but much lower efficiency). In general, if you increase the molecular weight of the propellant of a nuclear thermal engine, you lose efficiency but gain thrust. NERVA was an engine in the 50's that used hydrogen at ~950 Isp and had a thrust to weight ratio of 5, however a much more modern study into the technology predicted that with new methods and materials we could build hydrogen-fueled NTRs with thrust to weight ratio around 20 to 30 and slightly improved Isp compared to NERVA. Using methane as a propellant in an NTR engine that achieves 1000 Isp using hydrogen gets you ~600 Isp, which still makes it much more efficient than a hydrolox chemical engine. It also increases the mass flow considerably, so an engine that achieves 25 TWR using hydrogen may achieve 50 TWR or more using methane. This is comparable with an average chemical engine, while still performing much better in terms of Isp. Now, an after-burning NTR can't get as efficient as a chemical engine using the same propellants, simply because the NTR cannot achieve the same chamber pressures as a chemical engine. After-burning mode is tailored towards increasing the TWR significantly in order to get off the pad and fight gravity losses quickly, until such time in the flight profile that it can be shut off and the remainder of the delta V be supplied without using any oxidizer. Using an after-burning design makes more sense if your primary mode supplies a very low TWR, like NERVA did. However, if your NTR can achieve 20 or 30 TWR using hydrogen, and comparable TWR as a chemical engine when using methane, and the entire time gets you an Isp roughly two to three times higher, then a bimodal methane-hydrogen NTR makes more sense IMO. In short, after-burning NTRs are an old idea brought about to give nuclear thermal engines a high enough thrust to weight ratio that they could be useful during all phases of launch, and not only as upper stages. However, improvements in materials and nuclear science in the decades since NERVA suggest that nuclear thermal engines can achieve useful thrust-to-weight ratio for launch without afterburners, and that a bimodal engine that can switch in flight from using methane to using hydrogen would be superior to any after-burning NTR of any propellant combination. Read More 39 Reply

So we know about shock cones. Used with intakes to slow air for turbofans or turbojets to use. It had me thinking... could linear wedge shock cones work? I do not see why not. Linear wedge aerospikes do, and they are arguably harder to make anyway. Now I know some might say DRAG. Yah. I know. But if one puts the spaceship on a rail and accelerates it to ramjet speed and launches it into the air, then even with the drag if one has a nuclear airbreathing engine and some suitable rocket propellant, there should be a way to keep it flying with as much propellant savings as possible. So what say you, are linear wedge shock cones viable at all?

Answer 1: The same direction the ship would go if it actually were accelerating as fast as it translates. I called it a slingshot for that reason, since it is virtually the same concept, only moving space instead of actually accelerating. Dropping out of warp puts you out at the same trajectory only at your normal speed. For all intents and purposes, your vessel will follow a linear path during translation, so orbiting or thrusting to change trajectories just sets up your shot.

I well know the point of background music, it adds to the drama, and for some movies makes up for lackluster plot. For example Tron Legacy I best remember as an extended music video. The original had more character and plot, even though the big bad was as generic as can be; everything else in the concept was executed well. Interestingly, the original Tron had far less music, and was also more immersive for it I think. So I am curious... take away ALL the background music to the last movie you saw and tell me how good it is now? Or if it was good at all? It is my opinion that without music to lean on, it forces directors to have to compensate somehow... hopefully with better plot and acting. The only music that can be retained is ACTUAL in movie music playing in the background that characters also hear. So that totally eliminates epic sounding music like this playing as the heroes approach the villain's lair. Unless he is a total nerd who likes to blast that stuff on his speaker's outside his place. So what now? Do you still like the last movie you saw?

Clever. Nice. Here I thought I had a really tough scifi drive. There is one caveat though. The reason your mass lock is 100 kilometers is because that is the radius of your warp field. In other words, once you drop out of warp via detachment, youe warp drive section will be 100 kilometers away... at a relative stop to you since you were traveling together at first. No problem... your antimatter thermal rockets with propellant can handle that easily. Time is all that matters really, faster recovery equals more methane propellant spent and vice a versa. EDIT: Still... changing your trajectory using propellant alone will be costly. The cheapest way to go would be to use mix of propellant and gravity assist, then finally engage the warp to get where you want to go. No matter what you will need to keep an eye on how much propellant you have left, since if it is too low you would have either find a way to ISRU on some barren world or find a way back to your home system and call for help to get refueled after detaching the warp drive. At the very least... it gives an opening for pirates if nearby (lightseconds away).

Could work actually. Warp staging... who knew LOL. I am still wondering if any of you are witty enough to figure a way to acomplish single stage warp. Doing it in the home solar system is straightforward enough Light years away with light lag coming into play? Hard.

This a fun scifi scenario with some relation to reality: You have a scifi starship in orbit fully fueled with propellant and cargo, using antimatter thermal rocket engines with methane propellant. Yet to to reach planets and star systems in a reasonable amount of time you use: Slingshot Translation (ST) drive: Which moves space past your ship, translating your ship across space without acceleration. Similar in function to a warp drive. It has two speeds only. Lightspeed and a lightyear per hour. The catch is how the ST drive works... it will translate indefnitely without refueling UNLESS you are within a 100 kilometer range of a mass that has more mass than your vessel. Trust me, that is generally not a good thing, since the only way to stop translating would be to leave your starship. With shuttles or escape pods, which would be stranded in deep space while the starship continues merrily chugging along translating/warping space. If you start translation across space the direction you translate/warp to will be the same direction as your current trajectory. In other words, if you are orbiting Earth and turn on translation then to viewers you will appear to shoot out of orbit at lightspeed, even though you are moving space... not your ship. If you went out at max translation (LY per hour) they would just see you gone in a blink. Results: Careful planning is required, since you need to know the trajectories and speeds of target destinations BEFORE you arrive. Otherwise you will travel indefinitely at warp, leaving with you with two options: 1. Adjust your warp speed to lightspeed when passing through solar systems and hope a mass greater than your vessel's mass drops you out of warp. But space is BIG, and the radius to mass lock (drop out of warp) your warp drive is relatively small (100 kilometers). 2. Abandon ship inside a solar system while warping near a planet at lightspeed. Your starship is gone but maybe you can make it with shuttlecraft to this alien planet over there? Main question for discussion: Without FTL sensors... how in the world do you navigate to places you have not been before? Assuming you have not sent ships to scout ahead of you. You are the scout! Your mission, if you choose to accept it, is to seek new resources for your civilization, discover new worlds and cosmic phenomena, and boldly go where no human has gone before. Bonus question: Where do you choose to go? You have a total of 3 solar systems to explore before returning to Earth, alternately you can trade one solar system visit to explore cosmic phenomena (black holes, novas, pulsars etc).

Boom?

Nice. I see they went to sleep with smiles on their faces. Animals are smart for what are they are capable of... taking our stuff among them. We take their stuff, they take ours. Balance. It defines existence.

Well... that narrows things down quite a bit... does'nt it? Instead of a plethora of scifi SSTO shapes like this... this... and this, we get something that actually is designed to be an SSTO rather than look like a scifi derivative trope. This: Only with a cone that was sharper and more oblong and with a more convex bottom. That is the optimal SSTO shape with a shock cone intake. Thank you for helping me find it.

Nah... just the first one. I love the scene where they launch a nuke and... surprise, surprise, no SCIFI SHIELDS! Yet seeing the alien ship repair the damage so rapidly was far more scary than a typical scifi alien invasion. These aliens are seemingly inspired by horror movie monsters who cannot be stopped... only stalled.

Battle Of LA Personally, I found the Skyline movie (first one) aliens far more scary. Humans actually lose for a change. They go down swinging though, which is admirable.

There is also magnetohydrodynamics. Ion-propulsion within the atmopshere essentially, plus other ways too. Not sure if it is the same principle (doubt it), but there are a variety of ways to fly big stuff... really good MHD will unlock flight in ways that should exceed mechanical turbines. This is weak... but we should get better later on. http://news.mit.edu/2018/first-ionic-wind-plane-no-moving-parts-1121 https://www.google.com/amp/s/www.theverge.com/platform/amp/2013/4/3/4178708/ionic-thrusters-more-efficient-than-jet-engines-says-MIT-study Once we scale it up... fun times. Just need power on scifi scales. Which I have... in scifi.

Even so the ship is still going to have pointy shock cones sticking out of it, and trying to put nacelles on wings is a bad idea due to shear wind force ripping them off. Honestly... I think to make ANY shape fly we need a type of field control to suck enough air into the engine that the mass flow rate is on par with chemical rocketry. Not possible I know, but it may be via EM shenanigans or something else one day. This won't be a NTTR per se, it would need to be something more, as mere fans probably cannoy handle that. Shock cone still might come in handy. I dunno. Nonethless, if one really could suck and blow out that much air, anything nearby overhead would get sucked toward the engine. Think vacuum cleaner on steroids. The thrust would be dramatic to say the least... rocket like, only with air, likely a plume effect due to compression.

LOL. I do not have the heart to write such a scene even though I could. At most I might have such a character who has done such cruelty, trying to actually become someone who does NOT do that. Which would be hard... but possible. Not to mention dealing with survivors who know exactly what the character has done. I guess what I am getting at is that seldom is it the case that a hero in war is simply a hero who saves lives. Others would consider them a war criminal. You know the statement that one man's hero is another's villain? That is more true than I even believed my early days. I used to think that was something smarmy villains said on star trek (*cough* Dukat), but in reality that is VERY true. Being cruel is cruel no matter who is doing it l, be it the 'good guys' or the 'bad guys'. I would attempt to give that some clarity, and if there was an alien race noble enough to not go around doing whatever they liked to conquered females and prisoners, I would guess on some level their adversaries would respect them, even if they did not return the favor, they may at least be more willing to surrender knowing the victors are not going to go Assyrian on them.

My experience with scifi is mostly from TV, namely Star Wars, Star Trek, and Babylon 5. Of them all Babylon 5 inserts the most realism, but even then, it does not come even close to how atrocious war is IRL. Often war is glorified as noble and righteous, but IRL it rarely if ever is. Revenge upon revenge leads to atrocity after atrocity. I won't get into detail... as it is beyond forums rules, you can look it up if you wish. The conquest of Berlin did not go well for the women. In some cases they resorted to getting in relationships with one conquering high rank officer simply to avoid assault by large groups. Other times they tried to disguise themselves as men or very old women. Neither did things go well for prisoners in the pacific front. Let's just say some people were running low on food and leave it at that? Visual media scifi never really seems to go this dark, neither am I suggesting it should. At the most, I do like it when war is presented as it truly is... which is usually a lot of carnage and wrongs that cannot be justified even if one tries to. No, I don't suggest graphic recreations, but I would at least mention it offhand in conversation, or tell instead of show. Since there are some things that really do not need to be seen. I just am tired of war being sanitized as if it is cleaner and not as damaging as it truly is. In scifi.