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Post by bigbombr on Aug 20, 2017 16:22:45 GMT
Maybe adding luminosity to CelestialBodies.txt should help a lot in implementation of solar panels and thermal control systems for spacecrafts operating near hot objects. Also adding something about solar intensity in orbit.
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Post by Rocket Witch on Aug 20, 2017 17:21:04 GMT
Does the WFNA stats include an inhibitor compound? I don't think the game models tank corrosion and stuff or fluorine would never be used as rocket fuel! Awesome thread btw! <3 You should add aniline and aerozine 50! It isn't inhibited, for a few reasons I would say. One tends not to find hard data sets for properies of mixtures, just comments like "reduces freezing point". For the same reason, while one could make aerozine 50 by averaging the properties of hydrazine and UDMH, I don't know if this is really appropriate as it tends not to reflect the actual properties the mixture is desirable for. And, RP-1 had its real composition when the game released, but this lead to abnormally poor ingame performance so it was changed to pure n-dodecane. Making a proper IRFNA would probably suffer the same sort of issue, but since someone modded iodine in recently I might try making the AK-20I mixture. I'll also make a stab at aniline and let you know how it goes. Certain metals will passivate in contact with pure nitric acid. In particular I've defined elgiloy, which is made of cobalt, chromium, nickel and iron, all of which resist nitric acid, and it has good strength for propellant tank use: childrenofadeadearth.boards.net/thread/1692. You can also use the stock nichrome (nickel chromium iron) and waspaloy (nickel chromium cobalt). Far as I know, fluorine tanks could be made of nickel alloys and/or lined with something like PTFE, but I don't know to what extent it's feasible to then start getting heated up by lasers or pumping the stuff around. Combustion chamber would probably have to be made of aluminium nitride, which the core fluorine-hydrogen rocket design is.
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Post by RiftandRend on Aug 20, 2017 18:53:23 GMT
Radar has to fight hard against the inverse square law, limiting its practical range. You can mask a ship against radar. It is near impossible to mask a ship from IR and its acquisition range is extreme. I never said early warning would be done with radar. Strategic interplanetary detection of hostile space vehicles has to be done with infrared telescopes, because of the extreme range like you said. But you need radar too, in case anything is against the background of a bright planet, or lost in the glare of the sun, or so dim you won't be able to even make it out until too late. It may have to fight against the inverse square law but radar still works out to a long distance based on the size of your antenna, and big ships can afford big antennas. At the practical range for laserstars, a big telescope will see a blob of pixels for a target, and be super inaccurate, but attach a radar to it and you can see individual modules to shoot at. Plus for active radar homing missiles and drones at least it's not even an issue considering how close they get to the target! Stealth coatings and shape really don't work very well, it's just another in a long list of ECMs, but a highly skilled pilot aways beats advanced ECM. It's not like an unbeatable shield. For equally skilled pilots whoever has more advanced systems has the upper hand in the EM spectrum thou, but that doesn't make radar obsolete even a little IRL. Either way, it would be simple to add - design an antenna and just check to set it from passive to active (adding a radar set) and I think weapon accuracy would go way up, and you could resolve their orbit way faster Stealth coatings and shape are very effective against powerful radar at relatively short ranges. I believe at the very long combat ranges this will make radar irrelevant as a detection system. It is far easier to improve the resolution of a telescope than the range of a radar system. Additionally, telescopes are significantly lighter and require far less power than a radar system. I don't know what you were meaning by pilot skill beating ECM. Pilot skill should not be relevant as no human should be directly controlling the ship. Some kind of computer would be plotting random doge maneuvers
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Post by princesskibble on Aug 20, 2017 19:26:08 GMT
I never said early warning would be done with radar. Strategic interplanetary detection of hostile space vehicles has to be done with infrared telescopes, because of the extreme range like you said. But you need radar too, in case anything is against the background of a bright planet, or lost in the glare of the sun, or so dim you won't be able to even make it out until too late. It may have to fight against the inverse square law but radar still works out to a long distance based on the size of your antenna, and big ships can afford big antennas. At the practical range for laserstars, a big telescope will see a blob of pixels for a target, and be super inaccurate, but attach a radar to it and you can see individual modules to shoot at. Plus for active radar homing missiles and drones at least it's not even an issue considering how close they get to the target! Stealth coatings and shape really don't work very well, it's just another in a long list of ECMs, but a highly skilled pilot aways beats advanced ECM. It's not like an unbeatable shield. For equally skilled pilots whoever has more advanced systems has the upper hand in the EM spectrum thou, but that doesn't make radar obsolete even a little IRL. Either way, it would be simple to add - design an antenna and just check to set it from passive to active (adding a radar set) and I think weapon accuracy would go way up, and you could resolve their orbit way faster I don't know what you were meaning by pilot skill beating ECM. Pilot skill should not be relevant as no human should be directly controlling the ship. Some kind of computer would be plotting random doge maneuvers it's like when Serbian SA-3 operators shot down a F117 in 1999.
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Post by RiftandRend on Aug 21, 2017 0:59:27 GMT
I don't know what you were meaning by pilot skill beating ECM. Pilot skill should not be relevant as no human should be directly controlling the ship. Some kind of computer would be plotting random doge maneuvers it's like when Serbian SA-3 operators shot down a F117 in 1999. That's a very poor analogue to CoaDE. An F117 relies entirely on its stealth and has no active defences, such as lasers or railguns. The Serbians used specialized low frequency radar only suited for detecting stealth aircraft. Additionally, the F117 is an outdated aircraft by modern standards and it's stealth technology would be laughably outdated in the setting of CoaDe. While it's unrealistic to assume that only stealth would improve and not the radars it's hiding from, radar still has to fight vary unfavorably against the inverse square law for detection while telescopes do not. In my opinion, that fact combined with it's higher weight and power requirements radar make radar entirely unsuited for use in space combat.
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Post by princesskibble on Aug 21, 2017 1:26:23 GMT
it's like when Serbian SA-3 operators shot down a F117 in 1999. That's a very poor analogue to CoaDE. An F117 relies entirely on its stealth and has no active defences, such as lasers or railguns. The Serbians used specialized low frequency radar only suited for detecting stealth aircraft. Additionally, the F117 is an outdated aircraft by modern standards and it's stealth technology would be laughably outdated in the setting of CoaDe. While it's unrealistic to assume that only stealth would improve and not the radars it's hiding from, radar still has to fight vary unfavorably against the inverse square law for detection while telescopes do not. In my opinion, that fact combined with it's higher weight and power requirements radar make radar entirely unsuited for use in space combat. Actually I meant that to be an example of how a weapon that is worthless in the hands of some operators becomes deadly in the hands of very skilled operators. Anyway nothing can do what radar can do! Within a short range (but not THAT short like people keep saying) it can detect everything no matter how cold, find exactly where they are and determine their exact shape and therefore their exact orbit. Active sensors are a tactical asset in every form of combat. In space, active sensors can control a laser to fire on individual modules, or guide a KKV to an exact collision, or discover tiny cold shells from a cannon to direct defenses on.
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ndeo
Junior Member
It's not a flashlight... It's a High-frequency relativistic boson cannon
Posts: 67
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Post by ndeo on Aug 21, 2017 3:29:12 GMT
In atmosphere RADAR may be better, but LIDAR would be superior in space due to its shorter wavelength
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Post by thorneel on Aug 21, 2017 10:36:55 GMT
That's a very poor analogue to CoaDE. An F117 relies entirely on its stealth and has no active defences, such as lasers or railguns. The Serbians used specialized low frequency radar only suited for detecting stealth aircraft. Additionally, the F117 is an outdated aircraft by modern standards and it's stealth technology would be laughably outdated in the setting of CoaDe. While it's unrealistic to assume that only stealth would improve and not the radars it's hiding from, radar still has to fight vary unfavorably against the inverse square law for detection while telescopes do not. In my opinion, that fact combined with it's higher weight and power requirements radar make radar entirely unsuited for use in space combat. Actually I meant that to be an example of how a weapon that is worthless in the hands of some operators becomes deadly in the hands of very skilled operators. Anyway nothing can do what radar can do! Within a short range (but not THAT short like people keep saying) it can detect everything no matter how cold, find exactly where they are and determine their exact shape and therefore their exact orbit. Active sensors are a tactical asset in every form of combat. In space, active sensors can control a laser to fire on individual modules, or guide a KKV to an exact collision, or discover tiny cold shells from a cannon to direct defenses on. Radar can be defeated/mitigated by varied techniques. Even today, we have radar absorbent material with inter-reflections to absorb as much as possible of it, radar transparent material, deflection toward other directions where (hopefully) there is no enemy detector... It doesn't make radar useless, nor completely stoppable, though. How effective would it still be for short-range targeting/guidance? Also, IR/visible detection can be completely defeated by hydrogen steamers. I wonder how radar-hidden you can make a hydrogen steamer (and vice-versa)?
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Post by bigbombr on Aug 21, 2017 10:58:17 GMT
Actually I meant that to be an example of how a weapon that is worthless in the hands of some operators becomes deadly in the hands of very skilled operators. Anyway nothing can do what radar can do! Within a short range (but not THAT short like people keep saying) it can detect everything no matter how cold, find exactly where they are and determine their exact shape and therefore their exact orbit. Active sensors are a tactical asset in every form of combat. In space, active sensors can control a laser to fire on individual modules, or guide a KKV to an exact collision, or discover tiny cold shells from a cannon to direct defenses on. Radar can be defeated/mitigated by varied techniques. Even today, we have radar absorbent material with inter-reflections to absorb as much as possible of it, radar transparent material, deflection toward other directions where (hopefully) there is no enemy detector... It doesn't make radar useless, nor completely stoppable, though. How effective would it still be for short-range targeting/guidance? Also, IR/visible detection can be completely defeated by hydrogen steamers. I wonder how radar-hidden you can make a hydrogen steamer (and vice-versa)? Aren't hydrogen steamers big and cylindrical (max volume, min surface to leak heat), while radar stealth is achieved by being small and angled (absorbing radar or deflecting it in any direction that isn't your foe)? Cylinders are known for being very unstealthy shapes, and are avoided in any type of stealth aircraft or warship (look at the railing on an Arleigh Burke class destroyer for example). So I'd say you'd have to pick between IR stealth and radar stealth, you can't achieve both to a satisfactory degree in a single design IMO. Also, in space there is no horizon to block IR view, nor an ionosphere to bounce radar of. Any imaging radar can do, IR can do too, without broadcasting your position or swallowing such large amount of energy. Identifying individual external modules with an IR camera is possible, and probably (shorter wavelength!) at higher resolution, assuming diffraction limited optics. Radar would (IMO) almost exclusively be used defensively, like the detection of inert projectiles, but mostly meteorites and for looking through clouds. However, IR can also detect debris, projectiles are very hot, and meteorites heat up by sunlight and are therefore hotter than background radiation. In conclusion, radar might be a backup for IR, but IR will outperform it in almost any circumstance.
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Post by thorneel on Aug 21, 2017 11:20:46 GMT
Radar can be defeated/mitigated by varied techniques. Even today, we have radar absorbent material with inter-reflections to absorb as much as possible of it, radar transparent material, deflection toward other directions where (hopefully) there is no enemy detector... It doesn't make radar useless, nor completely stoppable, though. How effective would it still be for short-range targeting/guidance? Also, IR/visible detection can be completely defeated by hydrogen steamers. I wonder how radar-hidden you can make a hydrogen steamer (and vice-versa)? Aren't hydrogen steamers big and cylindrical (max volume, min surface to leak heat), while radar stealth is achieved by being small and angled (absorbing radar or deflecting it in any direction that isn't your foe)? Cylinders are known for being very unstealthy shapes, and are avoided in any type of stealth aircraft or warship (look at the railing on an Arleigh Burke class destroyer for example). So I'd say you'd have to pick between IR stealth and radar stealth, you can't achieve both to a satisfactory degree in a single design IMO. Also, in space there is no horizon to block IR view, nor an ionosphere to bounce radar of. Any imaging radar can do, IR can do too, without broadcasting your position or swallowing such large amount of energy. Identifying individual external modules with an IR camera is possible, and probably (shorter wavelength!) at higher resolution, assuming diffraction limited optics. Radar would (IMO) almost exclusively be used defensively, like the detection of inert projectiles, but mostly meteorites and for looking through clouds. However, IR can also detect debris, projectiles are very hot, and meteorites heat up by sunlight and are therefore hotter than background radiation. In conclusion, radar might be a backup for IR, but IR will outperform it in almost any circumstance. The ideal shape for a hydrogen steamer is a needle-like double cone (optionally with a central hole for reflecting part of the incoming sunlight behind it though mirrors), which gives stupidly high endurance as long as you aren't going too close to the Sun, and the ship is big enough (endurance scales up with ship size). However, if you are ready to compromise on endurance, it can be any shape you want. The less Sun-cross-section to volume, the better the endurance is (hence the ideal double-cone shape). So the question is, can you make a decent stealth shape while not taking too much of a hit on endurance?
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Post by bigbombr on Aug 21, 2017 11:51:14 GMT
The ideal shape for a hydrogen steamer is a needle-like double cone (optionally with a central hole for reflecting part of the incoming sunlight behind it though mirrors), which gives stupidly high endurance as long as you aren't going too close to the Sun, and the ship is big enough (endurance scales up with ship size). However, if you are ready to compromise on endurance, it can be any shape you want. The less Sun-cross-section to volume, the better the endurance is (hence the ideal double-cone shape). So the question is, can you make a decent stealth shape while not taking too much of a hit on endurance? Intuitively, I'd say not. Hydrogen steamers already are hard to make without their cost and size spiraling out of control. Their heatpumps require energy and produce waste heat. This has to get rid of, requiring more energy and waste heat. I'd suspect that even if they were possible, they wouldn't be economical or competitive. Trying to make them evasive to radar is making a hard (and expensive) work of engineering even more so, while reducing their performance even more. Imagine a massive target with little payload, the delta-v of a NTR-warship and the acceleration of a MPDT-propelled craft.
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Post by thorneel on Aug 21, 2017 15:59:09 GMT
The ideal shape for a hydrogen steamer is a needle-like double cone (optionally with a central hole for reflecting part of the incoming sunlight behind it though mirrors), which gives stupidly high endurance as long as you aren't going too close to the Sun, and the ship is big enough (endurance scales up with ship size). However, if you are ready to compromise on endurance, it can be any shape you want. The less Sun-cross-section to volume, the better the endurance is (hence the ideal double-cone shape). So the question is, can you make a decent stealth shape while not taking too much of a hit on endurance? Intuitively, I'd say not. Hydrogen steamers already are hard to make without their cost and size spiraling out of control. Their heatpumps require energy and produce waste heat. This has to get rid of, requiring more energy and waste heat. I'd suspect that even if they were possible, they wouldn't be economical or competitive. Trying to make them evasive to radar is making a hard (and expensive) work of engineering even more so, while reducing their performance even more. Imagine a massive target with little payload, the delta-v of a NTR-warship and the acceleration of a MPDT-propelled craft. The heat pump is not necessary. Some variants have it, but it may not actually be worth it. The simplest version is simply boiling off cryogenic liquid hydrogen, keeping the ship surface at 20K. You can use cryogenic solid hydrogen to gain some heat sink capacity and very slightly more density (if it isn't eaten by extra plumbing), for some extra autonomy. You can use already liquid hydrogen as coolant loop with the hull, slowly melting the solid hydrogen, with some of it evaporating to make room for the now less dense liquid. Such a design has an ideal idle autonomy measured in months or even years for good-sized ones. A stealthier but much less enduring version has a helium coolant loop and super-cold solid hydrogen to keep the hull at cosmic-background 3K (though even 20K is already ridiculously hard to detect). This is where the heat-pump intervenes: you can put a heat-pump so you can dump heat from the hull even when hydrogen is at 3K already. Heat pumps are ridiculously inefficient at that, so you will have to dump much more heat into hydrogen than you are extracting from the hull. Still, even if it means dumping dozens of times more heat and considerably increasing complexity, going up to boiling hydrogen may still be worth it in order to, say, double or triple autonomy. Even then, such ship would probably have "hot" and "cold" modes, with normal 20K boiling hydrogen operations to increase autonomy, and 3K cold run for critical moments - not unlike a WWII diesel submarine. Using boiled hydrogen as thrust is both rather inefficient and ludicrously low-thrust, so any non-ballistic steamer would have additional engines. You can go for solar-thermal, which offers good performances but requires a bulky lens, which itself may be too complicated or inefficient to hide/cool. Nuclear-thermal seems a better choice. It has slightly lower dV and add a bit of heat even when idle, but is much simpler to integrate. (A drive with purely radar-transparent material is left as an exercise to the reader.) Any drive would have a massive expansion ratio for its nozzle, and a configuration so the chamber isn't visible from the outside, but this shouldn't be a big challenge for any mature spacecraft maker at this point. But the base design is actually rather simple, and most of the mass is hydrogen. With today's tech, the expensive part would be the superblack coating (Vantablack is expensive, and so far can't be made at such a scale) and developing an adequate nozzle. And developing a nuclear-thermal drive in the first place, but after 50 years it seems NASA is finally starting to think about it again, so worst case we should have one in 50 more years. So as the cost of the 20K version is, as far as CoaDE tech is considered, pretty low, the question is one of performances: what is the best autonomy we can have with a stealth-shaped design? I don't know enough about radar-evading stealth in space to answer that. Are there good resources online on the subject? All that said, I think detection is so far out of scope for CoaDE, and will probably stay that way for a long time. Even flares and the lobotomised missile targeting feel like placeholders we could do without at this point. What would be interesting, though, is a more detailed precision system, taking into account vibrations and turret precision for example, particularly for lasers. And with that dropping max range completely and allow for attacks to be carried from the strategic view, but this is quite longer-term at this point. Things like non-electric cannon reloaders (using similar systems to today's automatic guns) would be nice, and maybe other turret types would be nice. Would hydraulic systems make sense for a turret, for example? Showing the equations, some way to simulate, details on what exactly happens during combat, save ship sections, armour configurations, more pointers to how the ship is supposed to work so the AI can use them, some way to abstract volumes of fire so combat doesn't turn into a powerpoint slideshow, tandem staging, more layout options, all those are also probably more urgent as any detection system. And renaming conventional to chemical while we're at it
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Post by princesskibble on Aug 21, 2017 23:23:10 GMT
Radar can be defeated/mitigated by varied techniques. Even today, we have radar absorbent material with inter-reflections to absorb as much as possible of it, radar transparent material, deflection toward other directions where (hopefully) there is no enemy detector... It doesn't make radar useless, nor completely stoppable, though. How effective would it still be for short-range targeting/guidance? Also, IR/visible detection can be completely defeated by hydrogen steamers. I wonder how radar-hidden you can make a hydrogen steamer (and vice-versa)? Identifying individual external modules with an IR camera is possible With IR or TV you just get a picture, but with radar you resolve objects in 3D space, plus a radar antenna doesn't have to be kept cool to look at dim objects, real IR astronomy spacecraft quickly run out of coolant, and they couldn't look toward the Sun or any other bright object Anyway adding sensors is a must, whether we get active detection or not! <3 <3
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Post by bigbombr on Aug 22, 2017 5:28:52 GMT
Identifying individual external modules with an IR camera is possible With IR or TV you just get a picture, but with radar you resolve objects in 3D space, plus a radar antenna doesn't have to be kept cool to look at dim objects, real IR astronomy spacecraft quickly run out of coolant, and they couldn't look toward the Sun or any other bright object Anyway adding sensors is a must, whether we get active detection or not! <3 <3 Not all IR cameras require coolant. If you look up thermal images in a military setting, you'll see you can discern jet engine nozzles, cockpits, wing edges and even curves in the frame. Range can be determined with a laser rangefinder. You can use a spare laser turret for a closer look (after detection) at a signature for identification. So I'd imagine effective range for detection is much larger, and if you use a spare laser turret as telescope, the identification range would also be greater. As for the identification of external modules, a 2D-image with heat gradients seems better than a 3D-image. While operational, thermal leakage can assist in identifying the purpose (and energy flow) of a system. Overall, I consider radar a backup to IR+laser rangefinder.
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Post by princesskibble on Aug 22, 2017 16:14:15 GMT
With IR or TV you just get a picture, but with radar you resolve objects in 3D space, plus a radar antenna doesn't have to be kept cool to look at dim objects, real IR astronomy spacecraft quickly run out of coolant, and they couldn't look toward the Sun or any other bright object Anyway adding sensors is a must, whether we get active detection or not! <3 <3 As for the identification of external modules, a 2D-image with heat gradients seems better than a 3D-image. While operational, thermal leakage can assist in identifying the purpose (and energy flow) of a system. Overall, I consider radar a backup to IR+laser rangefinder. A laser rangefinder does the same thing as radar (bouncing off a target i mean, weakening quickly with range), only it has to be aimed at a target, instead of finding range for every object in a radius! In the military there is a distinction between acquisition and fire control. Acquisition devices have to try to catalogue every hostile in range, what they are, and where they are going. You could try to do that with IR and a laser rangefinder but it would take forever to keep pointing the laser at each possible target and back as their orbit changes and you have to determine it all over again in an endless cycle (and I still don't think heat gradients could be better than a 3d image) If laser rangefinders are longer range than radar for the same antenna size and weight, than they could definitely be used for fire control thou! Althou they would be more expensive too
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