-Velocity-

What if an (optional!) random failures system was implemented? You come up with even a decent rocket in KSP, and it will literally never fail. There is no chance for random failures. What's the point of a launch escape system? There used to be some random failures on some designs (I had a rocket that would randomly explode in a spectacular fireball about 1 in 20 launches), but with the stronger parts patch in particular, these kinds of things have dissappeared. (Also, fixes of Kraken-like behavior helped remove random explosions.) I think that KSP is missing some explosions. Real rockets aren't as dependable. I would propose a new system of random failures. It would have at least three aspects- A) Random failures. Engines can randomly explode. Parts under stress can randomly break. Decouplers can randomly decouple. That sort of thing. It would make flying rockets much more interesting, because now there could be a chance that something would go wrong! Your Kerbals would actually be risking their lives when flying into space! You might actually need that launch escape system! Quality Control- Random failures, by themselves, would suck, and most people would hate them. There must be ways of controlling random failures and mitigating losses besides just blind luck. So I propose quality control. As you advance up the tech tree, you'd get better quality control (reduced chances of failure). You could also apply quality control on an individual basis on rockets you fly, for an additional cost. For example, the same rocket could go fly inexpensively for unmanned payloads, but when carrying Kerbals, you would want to spend some additional funds on quality control to "man rate" it. And you'd spend an insane amount of funds on quality control for an interplanetary transfer ship, for example. C) Insurance- You could purchase insurance for your rockets, so that if they fail you are refunded- just like real commercial space launches! It might be difficult, however, designing a system that can accurately detect a failure. For example, if one of your rocket's fins fails, you'll probably be fine, but a blind insurance system, that just refunds you if there is a failure, would think your rocket failed. Perhaps the insurance could work like the "revert" button, allowing you to file a "claim", immediately ending the mission and refunding you. Your insurance payments would go up on future rockets if you file a claim, keeping you from abusing the feature. How that would work for manned flights though, I donno. Anyway, I think that random failures, and the features that would go with them like quality control and insurance, would be excellent additions to the game somewhere down the road when it goes off (new planned) feature freeze, or in KSP 2, if there ever is such a thing. IMO, KSP sorely misses the realistic aspect of rockets randomly failing.

BTW, as an example, the stock xenon tank (the "PB-X150 Xenon Container", not the radial attached one), scaled up to 2.5 m, would weigh 7.68 tons full, 3.2 tons empty, and store 44800 units of xenon fuel (one unit = 0.1 kg). You calculate these numbers by multiplying everything by 64, since the radius increases by a factor of four and these are three dimensional objects, so their volume and (and mass) increases by radius cubed. 3.2 tons, empty. The Rockomax X200-8 Fuel Tank, which has similar dimensions to a scaled up PB-X150, weighs 0.5 tons empty. These are xenon tanks intended to go on a spacecraft, not sit around in some lab somewhere, so they are designed to minimize mass. I can't see how it's possible to make a case that 3.2 tons empty is a realistic number for a spaceflight application. BTW, a 4X scaled up PB-X150 xenon tank would measure about 1.25 meters radius by, let's just say 1.25 meters tall (I can't remember the actual length, but I did know it at one time). The volume would therefore be 6.14 cubic meters. Liquid xenon has a density of 3100 kg/m^3. If the tank's volume was 100% utilized as storage for liquid xenon, it would therefore hold about 19000 kg of xenon- or 190 thousand units of xenon fuel. However, a scaled up version of the tank only holds 44800 units of fuel. Therefore, the stock xenon tank only utilizes 44.8/190*100% = 24% of its volume to store liquid xenon fuel. Again, is that realistic?! HELL NO. So the stock xenon tanks are doubly unrealistic- they weigh far too much, and they only utilize about a fourth of their volume to store fuel. So, what I did for my scaled up xenon tanks is design a better, more realistic tank. Let's be conservative and say that the dry mass is 1500 kg - the tank must be heavier because the fuel is more massive, and maybe the tank needs some extra thermal shielding. I donno. But, while less than half the mass of the scaled-up stock version, 1.5 tons is still three times the mass of the regular liquid fuel tank of the same size! Also, let's say that it utilizes 70% of its volume for storing liquid xenon. This sounds pretty reasonable to me. 70% of 190 thousand is 133000, which is 13.3 tons. So a realistic, scaled-up 2.5 meter xenon tank using the PB-X150's shape holds 133,000 units of xenon fuel, weighs 14.8 tons full, and 1.5 tons empty. ANYWAY, all that said, you don't have to use ion propulsion to go a measly 2.5 billion km in a reasonable time span. NTRs will work just fine!

Thanks for the info- I didn't know what it was called. As far as the xenon tanks, if making my own mod that adds new, larger xenon tanks and engines is cheating, then any mod at all is cheating. You're "cheating" too, because you use mods. It's all a matter of perspective, and in my view, it's not cheating if it's realistic. When I made my xenon tanks mod, I used the real density of liquid xenon and the physical size of the tank to determine the amount of fuel the tank contains. I make the mass of the tank only like 10% of the mass of the xenon because xenon is an extremely heavy gas- liquid xenon is like 3 times denser than water. I don't just make up numbers to fit how I'd like them to be, I make up numbers to fit how it should be. When I was done, I had large, realistic-capacity xenon tanks. And boy were they heavy! Xenon is, in fact, the heaviest stable noble gas, so full xenon tanks SHOULD be very heavy!!!

Obviously, you're still limited by your ability to generate electric power. Say you have a nuclear reactor that outputs 100 kW for 10 years. The current results are showing like 100 uN of thrust for like 16W input power. Say your spacecraft weighs 2000 kg. 100 uN for 16 W is only 6.25 uN/W. With 100 kW input power, that's still only 0.625 N. After 10 years, your delta-V is only about 100 km/s. That's good for solar system travel, but still far, far, far less than what you need for interstellar. Now, obviously, it's likely to that the device would be able to be improved once we understood how it actually works, but- improved enough to enable interstellar travel? Probably not. Nuclear pulse propulsion would still probably be better.

No, there is no one here like that. If there is independent verification by an outside reputable source, and we start seeing some peer-reviewed journal papers, minds will change. The skeptics are skeptics because they simply don't see enough evidence. A small NASA lab who hasn't published any peer-reviewed papers on this, and some small Chinese lab are NOT reputable sources. Also, the skeptics are skeptics because they are NOT the kind of people who let their hopes and desires interfere with what they believe. A proper scientific mindset removes your desire from the results, because the greatest desire should always be the TRUTH. And the truth is, as awesome as a reactionless drive would be, it conflicts with centuries of science. I may not be an expert in the field, but when confronted with the "explanation" on how these EM drives work, my understanding is that the real experts in quantum mechanics scoffed at the idea. I can't be an expert in every field, and so I have to trust in their judgement. I'm not one of those people who, even though I have very little (or no) education in a field of study, is dumb enough to question the judgement of the actual experts in that field, and think I could possibly come up with something that they hadn't already thought of yet. The people (not talking about any of the people in this thread) who think they can second-guess what scientists and experts have to say on a subject really irritate me. /rant off But I think that's why we're skeptics. Until strong enough evidence is presented and/or the experts start changing their minds, the most logical conclusion is that this EM drive does not in fact work, and that this small NASA lab is not taking some factor into account or has some kind of other experimental error. To get all excited over these results is only setting yourself up for what is almost certainly going to be a big let-down.

Just don't get your hopes up, EM Drive fans. This is almost certainly not going to work out. Just because NASA is testing something doesn't mean it's reputable. I've actually worked in government. It was depressing. A lot of people just trying to justify their jobs, basically. So NASA isn't exactly the beacon of science it used to be. There are people there who can't be fired, basically, and can do some whacky stuff. So the EM drive is supposedly making thrust in a vacuum. Ok, if that's actually true, now, move the metal walls of the vacuum chamber away. I'm wondering if it's possible it's inducing eddy currents in the walls of the chamber that are providing a "thrust".

2.5x10^12 meters? That's not very far at all. Most things in KSP are like 1/10th scale; 1/10th scale to Alpha Centauri is still 4x10^15 meters! It seems to me they made this "Stella" more than one thousand times closer than would be realistic, even AFTER taking into account everything being shrunk in KSP by a factor of ten. Anyway, if you REALLY want to depart the solar system at very high speed, the trick I use is to fly out to the outer reaches of the solar system, then cut my transverse velocity to Kerbol almost down to zero (which won't take much because you're out pretty far). You deliberately put yourself into an almost sun-grazing orbit. At perihelion, your solar panels work ridiculously well, and you can generate enough power with one to power several ion engines. So at perihelion you fire your ion engines and zip away with most of your solar orbital velocity, plus like 40+ km/s. You can easily get 100 km/s final antisolar velocity with enough ion stages. Maybe something less extreme could be used if you really want to cut down on your flight times. Also, it's not hard to make your own xenon tanks and upsized xenon engines. The xenon tanks in the stock game are freaking horrible, only like 50% of their weight is fuel. It's very easy to edit some part files and make some bigger ones, with 85%+ fuel by weight. I've done them before, but they had the skins of the regular fuel tanks. Anyway, with big, efficient xenon tanks, a mulit-staged crewed electric-ion ship with 100 km/s dV is probably reasonable, but it will be very massive, a few thousand tons. If not 100 km/s, then close to it.

Ouch. Only 9% higher? So it's not very white at all, just lighter in color than the dark rocks/dust around it.

Your question can't be answered because you didn't give enough information. Is "27 km/s" the object's initial velocity or final velocity- remember, you have to eject something at greater than escape velocity for it to escape, and if I remember correctly, the escape velocity of a Milky Way-like galaxy is a few hundred km/s. If that's the initial velocity the object is ejected at, then we'll need to know how massive the galaxy is. I don't believe it would lose velocity from the universe's expansion, unless the expansion was accellerating. Yes, I know it actually is, but I don't think it would be a major effect at all between two relatively nearby galaxies. This would be an interesting point for me to research to make certain, because even if I'm correct in how the expansion of space works, I'd still probably learn something new. Unfortunately, I don't have the time right now, and I'm probably right anyway. If the expansion of the unvierse was capable of robbing objects of velocity, then galaxy clusters that were gravitationally bound would slowly come apart, would they not? Our orbit around the Sun would be slowly expanding. I do know for a fact though that Hubble's "law" breaks down when the distances are "very short"- like the distance between the Milky Way and M31 (the Andromeda Galaxy). At distances of like 10 million light-years and less (depends on how clustered matter is) individual galaxy motion becomes more important that Hubble's Law. Only at longer distances does Hubble's law really become dependable. A good case in point IS M31. It's moving towards our galaxy (at something like 200 km/s if I remember correct), and so its light is actually blue shifted, not red shifted. An object escaping M31 and moving towards the Milky Way will get here some time before M31 collides with us.

I do wonder, what is its albedo? Ceres is much dimmer than Vesta in the sky, so that probably means it has a much lower albedo, since it is about the same distance as Vesta AND angularly larger. So how white is the spot? I've been kinda assuming it's some patch of ice, but if it's simply, like a 40% albedo feature on the surface of an object that has an average albedo of like 10%, maybe it's not ice. Ice I think generally has an albedo of what, 90%+? Well, we won't have long to wait, at least! Maybe we should start a betting pool! Hmm... you know what I'm HOPING- because it would be fascinating- is that it's ices from some kind of eruptive feature (geyser or cryovolcano) that have settled back down to/flowed on to the surface to make a white coating. Maybe it's a recent impact crater that punched through into an icy mantle? Could it be ice that just happened to settle into a crater? If so, its latitude is awfully low for that, you'd expect that more by the poles- I think that surface ice would slowly sublimate at Ceres' distance,or no? I don't know much about sublimation.

Yea, that's what you think. But I know the truth- put on your tin foil hat so they don't wirelessly erase this knowledge from your head- they used a battleship to defeat an alien invasion a few years ago near Hawaii. They made a documentary from top secret footage Snowden leaked about it. I read about this on the internet, so it's true.

That is an incorrect unit for the expansion of the universe. The Hubble Constant is given as km/s/Mpc- that's kilometers per second per megaparsec. 1 Mpc is 3.26 million light-years. So if a galaxy is 100 million light years away, that's roughly 30 Mpc, and so it would be expanding away from us at 30 Mpc * Ho = 30 Mpc * 70 km/s/Mpc = 2100 km/s. So whether an object ejected from another galaxy will reach us or not is a function of how fast it is ejected and how distant the galaxy ejecting it is.

Is that plane yawing sideways? "Whatever crap" is a little vague. If it's yawing, I've had numerous problems like that. I will have perfectly stable aircraft that, at a certain altitude, just starts yawing sideways. I think it has to do with a thrust imbalance as engines begin to flame out or something. It's really annoying. The only way I "fix" it is to learn for each specific aircraft when it will usually start happening and switch to rocket engines before it starts. Oh, another way to fix it- and this only works for very small space planes, of course- is to just use a single jet engine

This is what I do. Only for Eve missions have I ever built a rover that is not in fact also a rocket powered lander capable of flying back into orbit. In KSP, it's so easy to get into orbit and wheels are so lightweight that it's pointless to separate the functions of lander and rover, except on Eve and maybe Tylo, but I've even built rovers capable of landing on Tylo and flying all the way back into orbit again, all in one stage, and using only stock parts. Only for Eve is that not possible.

One time, running low on my overall fuel budget, I decided to use some of my fuel on my lander just to reduce the altitude of my orbit around Tylo. This put me further behind on my total delta-V budget than I realized. On ascent, when my lander flamed out, I still had like 200 m/s delta-V left to go till orbit, and no saved games from before I made my landing! Jeb had to bail out, grab all the science, and use his EVA pack to take him the rest of the way into orbit.

Agreed. Also, fuel based on volatiles is not expensive if you can mine it in-situ. For example, I'm pretty sure we're about to find out that Ceres has a lot of ice. Ceres would have extremely low launch costs, as it has no atmosphere and very weak gravity. It could be the best fuel depot in the solar system, because it's not TOO terribly far from Earth and is likely to have easily-accessed volatiles in great abundance that can be cheaply put into orbit around the Sun. We could make a series of robotic NTR fuel ships that ferry volatiles from mining bases on Ceres to places all over the solar system. That is, if Ceres really has volatiles in abundance, and there aren't any "pesky" subsurface lifeforms there to raise contamination and ethical concerns.

Magnets don't work like gravity. They are dipoles, so in the far field the strength falls off with 1/r^3, and their fields are not spherically symmetrical. (The extra 1/r comes in there because the farther you are away from magnet, the closer and closer the two poles get relative to your distance away from them.) It would be far better to do this experiment with balls with opposite electric charges. You could make those work exactly similar to gravity, since the equation for Newtonian gravity and Coulomb's law is essentially the same. If you put them in a vacuum chamber, you could make them orbit each other indefinitely.

Oh and a final note, you might want to separate your crew quarters and your lander. What I mean is, Kerbals always wear spacesuits in space, so why do they need a pressurized living area on their lander and ascent spacecraft? Just throw a 50 kg command chair and that, plus the (40 kg?) EVA'd Kerbal means you only have to have a mass of (90 kg?) for each Kerbal. No need for a crew cabin that weighs tons. If you want a living area for your Kerbals to live in, then separately land a living quarters that stays behind on the planet's surface after the Kerbals leave. Heck you can even revisit it later if you want. Substituting command chairs for pressurized crew cabins, you can make some incredibly small Tylo landers. I'm trying to remember the weight of my smallest one, it might have been only 10 tons. It's also possible to make some really nice and cheap Eve sea-level-to-orbit spacecraft this way. I made one that could take four Kerbals from Eve sea level to like a 500 km circular orbit, and only massed 300 tons or so. I did put a "windscreen" (a 2.5m - 1.25 m adapter) over their heads to shield them from the atmosphere during ascent. Do be warned though, there is a problem though with quick-saving and quick-loading while Kerbals are in command chairs. Sometimes they get kinda screwed up, and when you try to disembark from the chair, the Kerbal can clip into the vessel and be ejected from the area at a few hundred m/s, or even cause the vessel to break up and explode. However, if you do some experimenting back at Kerbin, utilizing the save game and load game features, you can make spacecraft that are largely immune to this problem. Oh and also, if the mothership that launches the lander has RCS, there's no reason to put RCS thrusters and fuel on the lander. Omitting RCS can give you a few hundred additional m/s of dV.

6500 m/s dV is overkill; you only need something like 5000-5100 m/s dV for a Tylo lander, though I always have at least 5500 m/s just to be on the safe side. You always want a considerable margin for safety sake. Your TWR can start fairly low, like 1.3, as in the beginning of the descent you are not acting against gravity, but the TWR needs to rapidly climb as you slow down. With the fully reusable Tylo landers I build, I usually start with a TWR of like 1.4 - 1.5, I usually have a dV of like 5700-5900 m/s. Perhaps the way you're descending towards planetary surfaces is your problem. You want to burn retrograde, continuously at 100% throttle, until you touch down. It's basically an inverse gravity turn. Now, because that's very difficult to time, especially on Tylo, you start your burn a little early. Consider if it takes 5100 m/s to land and take off, and your lander has 5800 m/s dV, then you've got up to like 90 seconds of hover time on Tylo. That's quite a cushion for error. Now, what's the right time to start this burn? IRL, they solve a calculus problem and figure it out. In KSP, we have something that is far easier and far less time consuming- quick save and quick load. Do you really think that someone would have the technical expertise to build a liquid rocket engine, but not calculate the right time to start a de-orbit burn? - - - Updated - - - No, aerospikes are a very bad idea for Tylo, and the 48-7S is the best lander engine for Tylo, bar none. The TWR is incredibly high, and the ISP is respectable. The high TWR means that almost none of the mass of your lander is engines. The aerospikes are awful in comparison, and should never be used unless you're in a thick atmosphere. TWR is critically important on Tylo because you have to have very high thrust to efficiently land, and the 48-7S allows you to achieve that thrust without weighing your lander down with a huge engine mass. IMO, the 48-7S is so good that it needs to be nerfed for gameplay balance. It basically represents a nearly massless way to fairly efficiently convert fuel into a high amount of thrust.

Well, how did you calculate the center of pressure? That would be my guess as to why it's actually stable, you're using the wrong assumptions for how drag works. Think about the incredible vortices that the big rectangle creates as it flies through the air. The conventional assumptions for drag may not apply. Now, I am not an aeronautical engineer and it's been a long time since I had a course on fluid dynamics. I'm sure there are more knowledgeable people on these forums for this topic than me. But think about this- if that big rectangle generates a huge amount of vortices behind it, shouldn't that mean that the air there is moving faster? Shouldn't that, through Bernoulli's principle, mean that you form a large low pressure area behind your rocket? That would mean that there is a large force applied, through the differential in air pressure, on the surface of the rectangle. Because this force is behind the center of gravity, and points away from the center of gravity, it acts to stabilize the rocket. Even without the action of vortices, there should be a difference in pressure anyway, just from the air being compressed in front of the rectangle by its forward motion, and expanding behind it to fill the void left by the rectangle's forward motion. That pressure acts against the huge surface of the rectangle, and stabilizes the flight of the rocket. Anyway, I think that something like that is responsible for the stability of the rocket. Anyway, I'm impressed your rocket actually flew and remained in one piece! A long time ago, I went to this high powered rocketry event near Huntsville, AL. One of the people launching rockets that day had built a small rocket with HUGE forward-slanted fins as his rocket for H and I motor qualification. On launch, the fins sheared off- leaving just stubs glued to the rocket- almost before the rocket even managed to leave the launch rail. As the fins came slowly fluttering back to the ground, the rocket, freed of the ridiculously oversized fins, zipped away almost horizontally into the far distance. (Luckily, all the fins sheared off, evening out the drag, before it could turn more than 90 degrees.) I couldn't stop laughing at it. In my defense, I was only 13 at the time, but that probably made it even worse for the guy, to get laughed at like that by a kid. Though... it was a pretty dumb rocket design

So you ignore all my truthful statements and instead focus on a specific interpretation of a mostly irrelevant part of what I had to say, and try to point out a flaw in the reasoning of the irrelevant part. By the way, that is not an argument method that leads to any kind of intelligent discourse, or that is used in an intelligent discussion. It's a distraction "tactic" used by people who don't have a real counter argument, and who don't want to address the real topic of discussion because they don't understand the topic or know they would lose. To address your pointless nitpick, work is a quantity of energy. The units of energy are Joules and the units of work are Joules. If you interpret my statement of "Energy = work" as being all energy in a closed system, an interpretation no reasonable person would make, then of course that is not correct because globally, energy is conserved, and so this interpretation tells you nothing. No one with a technical background would make the nitpick you did, because it's silly and pointless, and everyone (else) knows exactly what I meant by it. Anyway, I'm not wasting any more time on you, you are a case of someone who refuses to learn.

You seem to be willing to have an open mind if someone just reasonably explains stuff, so I'll have a go- Energy = work = force*distance. A force can be manifest but do no work and create/require no energy, as long as the object its acting on does not move. This is why it takes no input energy to continuously magnetically levitate something. In fact, you don't even need superconductors to demonstrate magnetic levitation. Materials that are strongly diamagnetic will generate an opposing magnetic field to an externally applied one, and some are strong enough to levitate over rare-earth magnets. This occurs at room temperature. And yes, an object resting on a table is, in a very real way, being levitated electrostatically over the ground by the table. Remember how negatively charged electrons are located on the periphery of the atom while the positively charged protons are in the center? Remember how like charges repel? Well, when two surfaces come into "contact" with each other, what's really happening is that the surfaces get so close that the relative distance between the outermost electrons in the electron clouds in the surfaces of the objects is much less than the relative distance between the nuclei of the outermost atoms. Because the outermost electrons of the two surfaces are much closer than the outermost protons, a net repulsive force results, repelling the two surfaces from each other and giving the "illusion" of solid matter. Atoms very much have local, un-neutralized electric fields, and these fields are not uniform either due to electron orbitals, and from this arises all of chemistry. Oh, and by the way, in something mind blowing that even most electrical engineers don't know about (even those that study EM field theory!), is the connection between electromagnetics and Special Relativity. Magnetic fields arise from electric fields through length contraction of moving charges, and so, in very real way, are nothing but electric fields themselves. All of electromagnetics can be derived from Coulomb's law and Special Relativity. In fact, I think I read somewhere that one of the things that inspired Einstein was his conviction, eventually proven correct, that electric fields and magnetic fields were in fact the same phenomenon. BTW I am an electrical engineer myself so I know what I'm talking about.

This was my gigantic heavy lifter. The top part is a ~1800 ton test payload. Test payload in orbit- I'd load some pictures of it launching my interestellar probe, but it takes the game 10 minutes to load it on the launch pad, and half the time the game just locks up and crashes. The probe had too many parts for the memory allocation scheme to easily handle. If only they'd make some bigger xenon tanks...

And how did Earth's hydrocarbons get concentrated in sedimentary layers in the crust? Answer that. Also you don't understand one of the key differences between Earth and Titan. Earth lost almost all of its volatiles (such as water, methane, etc) during its formation. Titan did not, in fact, a huge fraction of Titan IS volatiles. So Titan is an iceball, composed largely of volatiles. So it has a lot of primordial methane and ethane, SIMPLE hydrocarbons. I don't believe there is any evidence that Titan has oil. Earth's interior, on the other hand, is so hot these hydrocarbons cannot exist, at least in significant quantities. Volcanoes would emit massive amounts of methane if this were not the case, but instead methane is just a trace gas. So we see that the majority of all of Earth's hydrocarbons are concentrated in the crust, in sedimentary rocks dating back to a few hundred million years. So where did it come from? There is only one reasonable answer, and it's the answer that is well supported by centuries of established science and evidence.

They've already invented this, it's essentially a flywheel with magnetic bearings. You don't even need superconductors. Yes, flywheels do work, they can store a lot of energy in a rapidly spinning wheel. This energy can be extracted easily electromagnetically, and fairly rapidly. Flywheels can be a competitor to, or superior to, capacitors for storing up large amounts of energy for rapid release, depending on the application. I haven't studied them in detail, I just know general facts, but I do know that I remember the Navy was thinking about using a flywheel to provide the high power pulse needed to fire a rail gun. I donno where that effort ended up going. There are, however, limits. With a high enough speed, the centrifugal forces will tear the flywheel apart. So there is a maximum speed set by the maximum materials strength of whatever the flywheel is made out of, and that means you can't even get remotely close to an energy density high enough to notice any relativistic effects. Solid matter is held together only by the small, un-neutralized, near-field leftovers of the electric force holding electrons around atomic nuclei. It can't be indefinitely strong.