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  1. Rough is correct, for reasons mentioned above. Terminal velocity is dependent not only on the characteristics of the atmosphere, but on the characteristics of the craft, and can change dramatically over the course of the flight (as a case-in-point, this is how parachutes work, though I admit that I do not know whether this is how their simulation works in the game). I can give you an explanation. That chart was an attempt to provide information that would be useful to players who had to work with few mods, few stock indicators, and a weird atmospheric model. None of those things is still true. It comes from this challenge: If you're not familiar with the Goddard problem, the short version is that it is an efficiency problem. The slightly longer version is that it is the question of how best to control a rocket to get the most altitude out of its propellant while taking into account the drag and atmospheric characteristics. It's of practical use because more efficient control means getting more out of a given load of propellant, but because of the reasons mentioned above, it's very specific to a particular rocket in a particular atmosphere. It's also only useful for a particular trajectory: straight up. Reaching maximum altitude is rather useless when the goal is to achieve orbit: the principles are different and the optimum solutions have almost nothing to do with one another. That being said, KSP is great for simulating these kinds of problems because it offers true reproducibility. It's also terrible for getting practical results from simulating these kinds of problems because it's not simulating other real concerns such as unavoidable variations in manufacturing the rocket, changing atmospheric conditions, or a fully-accurate aerodynamic model, among other things. However, at the time that it was made, that chart did provide some useful information. I'll provide details in the spoiler, mainly because it discusses completely outdated game mechanics and I don't want to create confusion. That being said, I think that this is actually a very interesting piece of KSP history, because this is from 2012 and people were still trying to figure out the mechanics of the game (and for a lot of them, spaceflight in general). Have a look at these cutting-edge graphics: Note the lack of lights, gear, and abort action groups. Also note that SAS was in the staging and had a finite capacity. Note the lack of info panels and KSPedia. Suffice it to say that there once was a time when people got to orbit by launching straight up and out of the atmosphere, then turning over and burning horizontally to make orbit ... hopefully before falling back into the atmosphere. At the time of this challenge, the atmospheric model was something like ten times more dense than what it ought to have been. Eventually, people settled on a hybrid approach to ascend in something (very) roughly approximating a gravity turn. What you see here is some of the experimentation that the players performed on their own to try to figure out those optimal ascent and control profiles. The terminal velocity table came from that. It worked at the time, so it made it into the wiki. After version 1.0 and the new model, someone noticed that a table of terminal velocities and altitudes no longer made sense for general use. It's not a matter of updating the table with new values for Eve: general values simply don't exist. An atmospheric density table would be nice, but density varies with temperature, which varies a lot with latitude and time of day, as well as altitude, so a table probably doesn't make much sense compared to an equation, or at least an algorithm. More pragmatically useful would be a list of good landing locations that combine high-altitude plateaus for launch with proximity to multiple biomes for research. Eve's rotation period is nearly four (Kerbin) days, so there isn't much to be gained from landing at the equator (55 m/s of eastwards rotational velocity instead of Kerbin's 175 m/s), but landing four kilometres above sea level is useful to avoid both the density and the heat of Eve's lower atmosphere. There is the idea that, given Eve's greater and more constraining challenges, the kinds of rockets needed to ascend from Eve's surface will be much more generally similar than the many and varied vehicles that come from Kerbin. In such a situation, you can make simplifying assumptions about the nature of these rockets to get a generally applicable range of solutions to the optimal ascent problem. However, those solutions are still dependent on the type of rocket, not on the planet itself, and so still wouldn't really fit on the wiki. But if you wanted to make a tutorial thread, however, then that would be a fantastic idea.
  2. There's a lot of factors at play here, the biggest of which is probably your gravity turn profile. The time you spend in the lowest parts of the atmosphere should be short either way, and the amount of time you wait till beginning the turn can make a big impact on dV margins. I think either Matt Lowne or Stratzenblitz came up with this technique for getting consistent turns, but a good way to repeat the same gravity turn profile consistently is to turn to five degrees on your navball right after launch then set SAS to prograde at a certain altitude (or speed, I cant remember but the latter may be better for low TWR launchers). Experiment with when you begin the turn and see what works most efficiently. Addendum: It was Stratzenblitz (3 parts to Duna, Ike and Minmus) and they began the gravity turn at 80m/s. That was for their particular vessel though and it resulted in the vessel intentionally overheating so you may benefit from experimenting with the technique.
  3. This is an in-depth tutorial, but still directed to beginner-intermediate players, on how to do a proper launch and gravity turn with the new aerodynamic model introduced as of version 1.0. This tutorial works for versions 1.0 to 1.3. More than giving a script or set of instructions, my goal with this tutorial is for you to gain an understanding of the factors that affect your rocket's behavior during launch, so that you can apply it to any rocket you fly. For that, you'll need to go through the entire post, but I'm also including a TLDR as a "cheat sheet": TL;DR (courtesy of @kBob) 1. Turn ON SAS and set throttle to give TWR of ~1.5. 2. Launch! 3. When your speed reaches 50 m/s, perform a pitch over maneuver (tip towards the East until pointing between 5° to 10°). 4. When SAS stabilizes (i.e. the control input arrows on the bottom left are all centered), turn it OFF. Avoid control inputs and use only throttle to control your gravity turn (throttle up to turn slower, throttle down to turn faster). 5. When your altitude reaches ~40 km, turn SAS ON. Start pitching down manually towards the horizon and adjust throttle to keep your Ap around 45 seconds in front of you. 6. When your Ap reaches the desired altitude, cut your engines, coast to Ap and circularize. ========================================================================================== General Notes on Gravity Turn You all probably know by this point that to get into orbit you need to go up, above the atmosphere, but you also need to go sideways (i.e. horizontally) very fast. To do this, we could launch straight up until we're out of the atmosphere, then point sideways and accelerate to orbital speed. But that would be very inefficient. We want to launch in a way that we gradually turn sideways while we ascend. This is called a gravity turn. The best way is to do a real gravity turn; that is, a turn caused by gravity and aerodynamic forces, rather than one achieved by actively turning the rocket. It is important to keep this in mind. Design Items Before even launching, you need to take these design items into consideration when building your rocket: TWR: Your thrust-to-weight ratio (TWR) at launch should be relatively low, around 1.5. A higher TWR at the beginning of the launch makes it harder for your rocket to turn naturally, as gravity will have less influence on its trajectory, making it fly straight and screwing up your gravity turn. Keep in mind that drag losses are almost negligible in the new aero, unless your rocket is shaped like a brick or you are going extremely fast in the lower atmosphere. Thus, a slightly higher TWR of around ~2.0 in theory is more efficient, but only if the launch profile is flown correctly. The drawback is it makes your rocket less forgiving in terms of control during ascent, and it shortnes your widnow to make a pitch-over maneuver. What usually ends up happening is that you have to force the gravity turn manually, which does generate significant drag (because you expose the sides of your rocket to the airstream anytime you deviate from your prograde vector), and causes steering losses (Dv wasted on changing direction rather than gaining velocity). This reduces overall efficiency and defeats the purpose of having a higher TWR to begin with. A higher TWR also causes increased stress to the craft, inducing wobble and risking a RUD, especially when trying to maneuver. You may experience heating issues too. For these reasons, in my experience, a TWR of ~1.5 is a good sweet spot between efficiency and controllability of the rocket. Smaller and lighter rockets handle higher TWR's better than big and heavy ones and each craft will have its own sweet spot; you are encouraged to experiment. If you find your TWR at launch is too high, either use a smaller engine or just throttle down, and vice versa. As a final note, all rockets will have their TWR go up as the launch progresses due to shedding weight by burning fuel. This is normal and you should manage by reducing throttle throughout the ascent as needed (more on this below). You can check your TWR with the Kerbal Engineering Redux mod (KER) or with MechJeb, or if you're running a stock game, the G Force meter roughly doubles as a TWR meter (if the G Force meter is pointing at 1 your TWR is roughly 1, and so on). Aerodynamic Stability: You want your rocket to be aerodynamically stable. That means that it will have a natural tendency to fly straight, instead of, say, sideways. Any object that flies through the atmosphere will naturally orient itself with its center of mass (COM) facing forwards relative to its trajectory and its center of drag (COD) facing backwards. You can see this in darts, arrows, badminton cocks, etc. Similarly, you will want to have your rocket's COM in front of your COD. To ensure this, add 3 or 4 winglets or wing surfaces with radial symmetry at the base of the rocket, and if possible cover your payload in a fairing to make it more streamlined. If your rocket insists on flipping, you need to add more/larger wings at the bottom. If that still doesn't fix it, it means your COM is shifting back too much as fuel is burnt. The heaviest part of a rocket in KSP is usually the main ascent engine(s), so the COM will tend to move back as fuel is spent. The easiest way to fix this is to add a small fuel tank at the top of the stage that's experiencing the problem and lock the tank in the VAB (right click on the tank and select the green arrows for both fuel and oxidizer). This fuel tank will act as ballast keeping your COM forward. You can unlock it manually in flight when the rest of the stage's fuel is gone so as to not waste it, and then stage as normal. Ascent Profile Once you've implemented the above design items, follow these steps for your ascent: 1. Turn on SAS and set your throttle to whatever will give you a TWR of ~1.5. 2. Launch! 2. As soon as your speed hits 50 m/s, perform a pitch-over maneuver to begin your gravity turn. To do this, tip your rocket towards the East slightly, until it is pointing between 5° to 10°. Don't start pitching over before your speed is ~50 m/s, otherwise you will likely find yourself horizontal within a few seconds, as your winglets won't be biting into the air hard enough to provide stability. The higher your thrust, the more you need to pitch over initially, because higher thrust makes the rocket want to go straight. If you're using a TWR higher than 1.5, your pitch-over should be to at least 10°. 3. As soon as your SAS stabilizes (i.e. the control input arrows on the bottom left are all centered) turn off the SAS. Watch closely for this moment, as you will have only a small window of a few seconds at most before the SAS starts trying to resist the gravity turn. Turning SAS off while it's trying to steer will cause your rocket to become unstable and lose its heading or possibly break up. You should be done with your pitch-over maneuver and have your SAS turned off by the time your velocity is around 100m/s. If you take too long and your rocket is going too fast by the time you're done, it won't want to continue turning (fast rockets like to go straight, remember?) and you'll have to force the turn manually, which is inefficient and causes stress on your craft. As mentioned above, a gravity turn should happen on its own and not as a result of control input. For particularly unwieldy rockets, you can lock SAS to prograde instead of turning it off during this phase. However, stock SAS is far from perfect and it's best to let gravity and aerodynamic forces do the steering for you. If you do use SAS, be sure to disable it before you hit 35 km to avoid you craft from jolting down suddenly when the navball automatically switches to orbit mode, which happens at around 35 km. 4. Enjoy the view while your prograde marker gradually sinks towards the horizon; your rocket will follow on its own thanks to gravity and aerodynamic forces. Try to avoid control inputs during this phase (i.e. no AWSD), just let it fly. If you need to make adjustments, use throttle. Remember, lower thrust means the rocket turns more, higher thrust makes it want to go straight. At about 10 km altitude, you should be pointing roughly to 45° and your speed should be around 500 m/s. If at 10 km altitude you're still pointing above 45°, your TWR was too high and you went too fast and/or your pitch-over maneuver was too gentle. Next time throttle down more or make a more aggressive pitch-over maneuver. On the other hand, if you're pointing below 45° at 10 km, you went too slow and/or your pitch-over maneuver was too aggressive. Next time use higher thrust or do a gentler pitch-over maneuver. If your rocket flips on its end at any point, it's not aerodynamically stable enough. See above under "Aerodynamic Stability" for possible solutions. 5. At around 40 km altitude, turn SAS back on and start steering manually; use pitch and throttle to keep your Ap around 45 seconds in front of you. Any time you're burning above the horizon, you're wasting part of your thrust to gravity instead of gaining horizontal speed; this is called gravity losses or gravity drag. In the initial stages of the launch, you can't help incurring gravity loses because you need to gain vertical speed to get out of the atmosphere. The atmosphere also means you can't steer away from the prograde vector without inducing aerodynamic drag, steering losses and/or destabilizing your rocket. However, by the time you get to ~ 40 km, you'll have enough vertical speed and the atmosphere will become negligible. Thus, at this point you want to begin gradually pitching down towards the horizon. During this phase, you will also start adjusting your time to Ap. It's most efficient to perform your orbital insertion burn right at Ap, so you want to keep it "hovering" only a few seconds in front of you. Of course, you don't want to it to get too close either, otherwise you risk passing it and falling back down into the atmosphere. A time to Ap of ~45 seconds is a good rule of thumb to balance safety and efficiency. To control your time to Ap, use pitch and throttle. If your time to Ap is more than 45 sec, throttle down a bit and point more horizontal, and vice versa. Avoid pitching below the horizon. Continue adjusting pitch and throttle until your Ap reaches your desired altitude, at which point you can cut your engines, coast to Ap and circularize. Note that as you approach orbital speed, there will be a point when your Ap will begin shooting away even if pointing straight at the horizon and no matter how much you throttle down (unless you cut the engines of course). If you reach this point, just let it go until engine cutoff; any efficiency gains from keeping your Ap near you will be negligible by then. Advanced Mode Try doing the ascent and orbital insertion in a continuous burn. This is the most efficient profile (citation needed) and it's extremely satisfying. Easier said than done, though. To pull it off, you need to allow your time to Ap to creep closer and closer during steps 4 and 5, while not allowing it to get higher than your intended orbital altitude. You do this by reducing throttle and lowering your pitch in a more aggressive manner. The closer you are to orbital velocity, the closer you can allow yourself to get to your Ap. You want to hit orbital velocity exactly at Ap. There will be much trial and error and the exact procedure will vary from rocket to rocket, but give it a try!
  4. I ask those with experience in real solar system how the gravity turn goes. in the stock game, you generally want to turn very fast, starting already around 50 m/s, being down at a 45° angle already at 500 m/s. that because in stock you orbit at 2200 m/s, you want to be horizontal at that speed. in real solar system, at 2200 m/s you still miss over 5 km/s to orbit. I had experiences where I did start angling down early, and I had to pull up later. on the other hand, I am now trying to go straight up until around 15 km altitude, and while this enables a proper gravity turn afterwards, going straight up at 700 m/s doesn't feel right. it can't be optimized, can it? and orbital launches in rss last way too long for me to want to go by trial and error. any good tip on when I should start turning?
  5. I'm attempting to build a massive SSTO rocket but when I attempt to start turning in the air my rocket instantly explodes. I'm using part clipping to get the diameter of the rocket smaller but from what I understood that shouldnt affect the physics of the craft. The flight log says that there was a structural linkage failure between two adapters high up on the rocket in a random spot. If it helps I'm using vector engines attached to an engine plate onto a 5m fuel tank.
  6. Build it like any other rocket, though you may want to preserve the aircraft shape by linking it to the launch stack by the belly rather than the rear, like the space shuttle. The only real problem is that the lifting surfaces the aircraft needs will strongly draw the rocket "upwards," and you'll need to account for that. Give the ship lots of control authority and maybe rotate it so that this trend works in your favor and helps make the gravity turn. Or you can use the really messy fix of making the craft symmetrical by copying the plane part on each side.
  7. I have been working on this EVE SSTO for a couple of days. Exploring how aerodynamics work in EVE atmosphere has been a lot of trial and errors. So far, I can get to 12km above sea level using propellers, and from there I switch to the rocket engines. The best I got is about 77km (AP). I have successfully built several SSTOs for Kerbin and Laythe, but EVE is just on a completely different difficulty level. How can I perfect this prototype into an actual EVE SSTO? More dv? Alternative engine setup? Aerodynamics? Better gravity turn? Drag seems to be a major problem the mk2 cargo bay can generate a lot of drag, but switching to service bay also generate quite the amount of drag too. (Don't worry about the change in the center of mass, I have altered how fuel gets drained from each parts. The center of mass doesn't change until the last fuel tank starts draining.) Nov 28 Update: I done did it! Thanks to all your tips, I made it to the low Eve orbit. Scroll down to see the pics and download link
  8. yes, of course it is. the terrier quadruple its deltaV in vacuum - though i don't understand how you can have 2 stages both based on terrier engines with similar twr there, unless it's some mod to rescale (i checked, only the terrier has that atmosphere Isp). anyway, this leaves you with 2300 + 2300 + 1200 = 5800 m/s. you should actually go to orbit and have half fuel left in the second stage. if you don't, then there are two possibilities. maybe the rocket is a lot more draggy than you think - just because it looks aerodinamic, it doesn't mean it is. aerodinamic is glitchy. or maybe you are not doing your gravity turn correctly
  9. I designed a basic rocket and it performed quite well. It even got into the gravity turn without need of steering input. Then I decided to try to explore the limits o the design a bit and among other thing I wanted to look how it behaved without the basic fins. To my surprise, it don't flip but also don't get into the gravity turn by itself. Despite being launched with more tilt than the original craft it went up. And is not that it didn't turn at all, rather it osculated slightly west-east, as if there was some sort of self-righting mechanism. Just I have no idea of what it might be. There is the craft file if anyone is interested in trying it for himself: Strange and a picture
  10. I have seen some guides say throttle down if it the turn goes too fast, but in someone else says no, do 5 degree force turn for adjustment. But which is actually better?
  11. hi, after several launches Gravity Turn gave me this values: This is the probes launcher: These are two videos that show the same thing: as soon as the first stage detaches, the launcher no longer can maintain the alignment with the prograde direction and for some seconds it pull up its nose in a non-aerodynamic fly. I just would like to understand why of this behavior? have any ideas? I don't know... too long fairing? Full launch: https://www.dropbox.com/s/69kj8n4zjilhxyy/launch.mkv?dl=0 Short launch: https://www.dropbox.com/s/ey9wt7hvsla5qcz/short launch.mkv?dl=0 Screenshot: (look navball aligment)
  12. Hello, Yesterday I was trying to launch with a proper gravity turn. My vehicle was a mk2 shuttle with an external tank and its TWR was a little low after the separation of SRB’s (about 0.8-0.9). However I noticed that the AP continued to rise even with such a low TWR. I then continued with a launch profile where I tried to keep the AP within a minute away. I had the TWR in about 0.9-1.1 during much of the ascent. All the time my AP was rising. I assume this is because as I increase my horizontal speed the ground “falls” away from me even if my TWR is below 1.0. Is this the way it works? Anyway, I got a stable orbit around 95km but I was wondering that such a low TWR during a ascent is probably not the most efficient way of launching (previous test run with about 1.5 TWR gave a 250km orbit). What kind of ratio should I aim at after the separation of SRB’s? Even if it wasn’t the most efficient profile it was a real pleasure getting a nice orbit with such a low TWR! And if nothing else, it had me cracking my brain for the rest of the evening, so all in all a massive success!
  13. pitching or yawing is only a matter of how your rocket is rotated on its axis. completely irrelevant. just aim for 90 degrees. it's not different from orbiting kerbin. what do you do when orbiting kerbin? as soon as atmosphere is no longer a concern, you aim 90 degrees. unless you want a polar or retrograde orbit, but let's not make confusion. on mun is the same, except that there is no atmosphere and so you can go for a much steeper gravity turn. also, with the lower gravity you need a lot less speed to orbit. incidentally, as long as you pick up horizontal speed, any direction will give you an orbit. 90 degrees is just more convenient for inclination
  14. your burn is too long and you start it too late. if the burn goes too long, you will reach apoapsis and then start going down. and since you are taking a very steep ascent, you go down fast. you need to ensure to finish your burn at apoapsis, hence you should start the circularization burn earlier. you should also make a much stronger gravity turn, because the way you are doing it, orbiting is a lot more difficult. you should be at least at 1500 m/s when coasting to apoapsis, possibly more. if you still make a mistake and end up with a low periapsis in front of you - your periapsis is in front of you, like in figure 4 and 5 - you can burn radial (away from the planet) and fix things. if you keep burning prograde, what happens is that you also raise apoapsis, which is why your apoapsis went way up in your last successful attempt. in general, if you burn prograde at periapsis, you raise apoapsis. if you burn at apoapsis, you raise periapsis. but if you burn in any other place - which is what you are doing, because your trajectory is so steep that you are only near apoapsis for a very short time and your burn is longer - you are going to raise both apoapsis and periapsis. so what happens to you is that you pass apoapsis while still burning, you move forward, and from then on your burn is used to raise both periapsis and apoapsis. and the further you go from apoapsis, the more your burn is used to raise apoapsis instead of periapsis. eventually you get to the point where you have a 500 km apoapsis and still a 40 km periapsis. and by now you're so close to periapsis that burning prograde does little good. this is why, in contradiction with what suggested by @James Kerman, i recommend finishing the circularization burn slightly before apoapsis (his advice still applies to most maneuvers). it's a lot easier to recover from errors like that. i set up for a 65 km apoapsis, and then burn prograde a minute or two before that. burning before apoapsis will also raise apoapsis, so i will finish out of the atmosphere once the maneuver is done. the advantage of this is that burning before apoapsis is going to retard your apoapsis. you look at the corner of the screen where is your time to apoapsis, and you will see that at some point, the countdown will revert and the time to apoapsis will start going up. at this point i stop the burn. wait a bit, then burn again. apoapsis is getting closer, closer.... the moment it starts getting further, i stop the burn and wait a bit more. until i enter orbit 10 seconds from apoapsis or so. very self-correcting. another way is to use a radial component. to orbit you burn prograde, which means parallel to the planetary surface. but you can also burn radial, which means perpendicular to the planet surface, in this case pointing upwards. it has the effect of raising orbit in front of you, but lowering it behind you. so, you are at apoapsis, and now you'll fall down towards periapsis; but if you burn a bit above prograde, you can raise orbit in front of you as fast as you are falling, therefore staying at apoapsis indefinitely. and it's not even expensive, it's only a small deviation over prograde; in fact, i think it's one of the most effective ways, though the main difference is for a proper gravity turn (again, i reinstate, you could save at least 500 m/s by making a better gravity turn). anyway, the way to do that is to press alt-f12, go to physics, then aerodinamics, then display aerodinamic window in user interface. it will open a window will a lot of aerodinamic data, which will be of little use to you because you're in near vacuum anyway, but one of those data is ascent speed. before apoapsis, you are moving up, so ascent speed is positive. after apoapsis you go down, ascent speed negative. when you reach apoapsis and ascent speed goes down in the negative, point your nose a bit above prograde, and ascent speed will start increase again. gradually it will become positive again, as apoapsis is again before you. you can go back to burning prograde at this point, or perhaps you can even burn downward if needed to compensate for too much ascent speed. anyway, by pointing your nose just above prograde and making small corrections, you can stay at the same altitude during all the circularization burn. this is also a very self-correcting technique. in fact, making the circularizaton with a maneuver node is a very uncomfortable way of circularizing. i have no idea why some people prefer it, cosine losses are going to mess you up. i always use one of the two self-correcting techniques i described above. p.s. your rocket has extremely high values of twr, especially for the upper stages. you could be a lot more efficient by using smaller engines, you'd cut down on your dry mass a lot. of course, with lower twr ascent is more difficult, so you should improve on that before lowering twr.
  15. I've been playing a bit of RP0 lately, and I am having a bit of trouble figuring out how quickly I should make my gravity turns. I especially have trouble with low TWR upper stages, such as ones using an RL10. Does anyone have a heuristic for doing gravity turns that could apply here?
  16. So, when I look at the Delta-V chart, going into LKO must "use" 3400 m/s of Delta-V. But me when I get to orbit I "use" approximately I use at least 4200 m/s of Delta-V. I know it's quite impossible to do as the Delta-V chart say but I find that I use too much Delta-V for LKO and I think that the problem is from my gravity turn. So do you have some tips to do an efficient gravity turn ? Thank you Fly safe
  17. Since the original got lost, I thought I'd revive the old FAQ thread. I think I found the most up-to-date version, but please let me know if anything is missing. All credit goes to the original authour for the time and effort spent in creating and maintaining the original list, so a big thanks to him for that. As with the original thread, please don't ask questions here, but feel free to suggest frequently-asked questions that can be added if needed. Frequent Asked Questions KSP in general. Q: Why is my game constantly crashing? Especially on scene changes. A: Most likely you're simply running out of memory. The 32 bits KSP version can't use more than 4GB. (The windows version dies at about 3.3-3.4GB on average, the OSX version at only about 3GB.) Loose some mods or switch to the 64bits version. On PC it's also possible to use -force-opengl. (Success not guaranteed but many people have had great results with it.) Q: I have 8GB RAM on Win7 64 bit. Why does my game keep running out of memory. A: As with the answer above. 32bit KSP can't use that extra memory. And even a 64bits game can run out of memory when too many mods are installed. Q: My computer has X cores, yet KSP runs at a low framerate. / KSP uses only a fraction of my CPU. What's going on? A: KSP runs on the unity game engine. As a result KSP physics are still single threaded. The physics calculations will jump from core to core but you can only only use one out of the X cores at any one time.. More cores will end up meaning you are using a smaller fraction of your processing power. Also, bear in mind that depending on what's slowing you down, the bottleneck might not be your CPU at all-- for example, your graphics card may be having trouble keeping up with visual f/x. Q: Can I de-orbit a moon? A: Short answer: No. Long answer: No. All planetary bodies are 'on rails'. Their orbits are fixed and can not be changed by in-game physics. Q: But what if they were not 'on rails'? Then you can de-orbit a moon, right? A: Still no. In theory it would be possible but the volume of fuel tanks required would be roughly the same size as the body you're trying to de-orbit. The game engine will not permit craft of that size. Even if the game engine would allow such craft it would take many decades to burn through that amount of fuel even at 4x physics warp. (YouTuber Scott manley 'tries' to de-orbit Gilly.) Q: I'd love to use mods, but that's not the way Squad intended it to be played, right? A: Did you notice the weekly showcase of mods by Squad on Modding Monday, and the six subforums devoted entirely to mods? The mods are there to enhance the game as you see fit! Q: How do I install mods? A: See "Running KSP with mods / add-ons" section, below. Q: Is MechJeb (or any other mod) cheating? A: The object of the game is to enjoy it. If you enjoy the game more using MechJeb (or any other mod), do so. If you enjoy the game more by not using it, don't use it. Don't let anyone tell you what the 'true' way of playing KSP is! Q: Is [modname] compatible with KSP version x.x.x A1: Search the forum for the relevant [modname] thread. Don't just browse through but actually READ the title, the first post and the last 2 pages. If you're still not sure check the dates of the last few posts and the date the OP was last edited. When the posts are all older than a few months or when a lot of posts just ask for updates you're probably out of luck. A well maintained and up-to-date mod gets at least a few posts per week. Also check the mod creators forum activity. Hover your mouse over his/her avatar and check the 'last visited' date. If the mod creator has not visited the forum in a long time the mod too is most likely abandoned. A2: When in doubt the easiest (and often fastest) method of getting an answer is to just go for it. Just download and install [modname] and see what happens. As usual you should make a back-up of your current game or create a separate install to keep your current game safe. A3: If all else fails, ask in the relevant [modname] forum thread. That's the place the [modname] users hang out. That's where they know the answer. Q: What is the official name of the Kerbal currency? A: It's called Funds () as in "The rocket costs 100,000 funds". Q: I don't understand why the game doesn't include [feature x]. It would be so much better with it! A: There is an entire sub forum dedicated to suggestions. However, make sure your request is not included in the 'Already suggested list', or on the 'What not to suggest' list. Keep in mind that being on the 'what not to suggest' list doesn't mean it won't be implemented; female Kerbals were on that list, for instance. It just means that Squad is aware of these requests but can not guarantee such a request would be implemented or even entertained. Also, while stock might not offer your feature, it's very likely that there's a mod for it! Q: When will the next update be released? A: Soon™ SQUAD never gives release dates to avoid disgruntled users when deadlines aren't met. Q: "The barn" What is it? Where is it? Why isn't it? A: The barn as it was shown in the previews was generally not received in a positive way by the community for various reasons, and thus left out in Career mode. Most complaints where about bad quality rendering (especially the textures), out of style with the other buildings and haphazard use of objects that didn't make sense (roads leading nowhere, etc). One of the most recent discussions about it can be found here. Launch, lift-off and orbit. Q: Why does my rocket flip when I turn 45 degrees at 10km? The tutorial says that's what I should do. Ashort: The tutorial you're looking at is outdated. Since v1.0 aerodynamics have drastically changed, drag has become a serious factor that can no longer be ignored. To avoid flipping start your gravity turn very shortly after lift-off and be gentle. If you get Mach effects in low atmo you're going too fast. Along: Drag pushes the rocket backward, while inertia keeps it going forward (along with thrust). The different parts of the rocket provide different amounts of drag and inertia: heavy parts provide more inertia while wings, airbrakes, and parachutes provide more drag. Since engines are heavy, their inertia will cause that part of the rocket to continue forward, while the drag on the rest of the rocket will pull it backward. Once the rocket tilts, this causes it to be forced into an orientation where the heavier end points forward - in this case, upside down. This is a real problem rockets have to deal with. The simplest solution is to add parts that provide a lot of drag (wings or airbrakes) at the back end near the engines. If this is not enough, even with careful flying, use the right-click menu to disable fuel in the tanks near the front until the tanks near the back are nearly empty, so as to keep the weight of the fuel near the front of the rocket and due to the above physical effects keep it pointed the right way. Q: My contract won't complete. A1: Are you sure you're orbiting in the right direction? Watch how the highlights on the target orbit are moving. You should be going in the same direction. Also check the AN and DN markers, if they are close to 180 you are orbiting in the opposite direction. A2: The contract system still contains a few bugs. If you are confident you've met all the contract requirements don't despair, Quicksafe [F5] and exit the game. Restart the game and return to the craft that failed to complete. Almost guaranteed now the contract will complete without a problem. Q: Why is it so hard to make a shuttle? A: Because shuttles are really, really hard. One of the hardest things to build in KSP. There are all sorts of off-centre thrust issues to cope with, which change quite radically as the SRB's then main tank separate. There are also lots of drag/lift problems with wings on a rocket. Almost any other way to get to orbit can be designed, built and flown more easily and efficiently in KSP. While you can easily find the parts to make a craft that looks like NASA Spaceshutle, that craft will not behave in the same way given the differences in mass, drag and thrust distribution. Q: Can you make a rocket as efficient as an SSTO spaceplane? A: Yes; build a rocket that uses a Single Stage to get To Orbit. It is exactly as efficient as an SSTO. It IS an SSTO. Spaceplanes aren't efficient because they are spaceplanes, they are efficient because they use air-breathing engines. The second factor that makes SSTO Spaceplanes economically efficient is that they are relatively easy to land back at KSC. The closer to KSC you recover your craft they higher the refund value. Landing back on the runway or launchpad will result in a 100% recovery value. But of course SSTO rockets can also be de-orbited and landed at or near KSC for full recovery. Q: SAS won't activate. Even though I have a Kerbal in the cockpit KSP says I do not have a pilot. A: Your 'pilot' might not be a pilot. Kerbals come in 4 types; pilots, engineers, scientists and tourists. All types have their own use and abilities (except tourists, they're just high-value seat fillers) and only pilots can use SAS. Higher level Kerbals have higher skills. To use more advanced SAS features either use a better trained pilot Kerbal or higher level probe core. Q: [.] (period) toggles the visibility of the NavBall. How do I permanently keep the NavBall visible in the map screen? A: Go to the main menu and open settings. Under the "General" tab uncheck the option to "Autohide Navball in Map View". Q: What is Delta-V / dV / ΔV? A1: dV literally means 'change in velocity'. Basically what you can do depending on the amount of fuel you have, the total weight of your craft and the efficiency of your engines. A2: Mathematically, delta-V is calculated with the Rocket Equation - it takes the form: delta-V = ln(M/Mo)* Isp *go Where delta-V is the change in velocity (a vector that's a dot-product of the scalar component of speed with the vector component of direction), ln is the natural logarithm function (look for it on a scientific calculator, or use =LN() in MS Excel), M is the full mass of the rocket stage, Mo is the dry mass of the rocket stage (i.e. what it weighs when all its fuel tanks are empty), go is standard gravity (9.81 m/s2regardless of what body you're orbiting/launching from) and Isp is the specific impulse of the engine (a way of measuring the engine's efficiency). It's importance, as has been mentioned, is in determining the total magnitude of the changes the rocket may make to its velocity before it runs out of fuel; in the process it determines where a rocket may go given a certain mission profile. There are three main ways of increasing a rocket's delta-V: 1) improving propellant mass fraction (i.e. moar fuel) 2) increasing specific impulse (by selecting an engine combination that increases this value - the main reason nuclear engines are recommended for interplanetary flight) 3) staging (shedding mass that's no longer needed, which has the effect of improving the propellant mass fraction) Atmospheric flight, rovers and surface activity. Q: My rover rolls over on low gravity planets/moons. A1: Widen your wheelbase and lower your centre of gravity. A2: Remap your controls to IJKL or use docking mode in order to steer independently from the reaction wheels. A3: Right-click all reaction wheels and toggle them off. (Most pods and command modules also contain reaction wheels.) A4: Toggle soft controls with [Caps Lock]. The orange pitch/roll/yaw markers in the lower left hand corner turn blue. Q: Why won't my parachutes deploy trying to land on Mun? A: No atmosphere = no parachutes. Parachutes only work on Kerbin, Eve, Duna and Laythe. (And Jool, but it is unlikely your ship will survive long enough to use them.) Q: My jet engines won't work on Duna/Eve. A: Jet engines need oxygen. Only Kerbin and Laythe have and oxygen atmosphere. Q: Why is my plane uncontrollable in flight? A: Planes that actually look like an real life aeroplane usually fly best. Although it is slightly outdated this tutorial will show you the basics. A more up-to-date tutorial can be found here. Q: Even at over 100m/s my plane won't take off before the end of the runway. A1: Your rear landing gear serves as a fulcrum. It's placed too far behind the CoM (Check one of the two tutorials). Another method is to design your plane to sit in the runaway with a slight pitch up angle instead of parallel to the surface. A2: With a Centre of Lift (CoL) too far behind the CoM your control surfaces might not be strong enough to push down the tail and lift the nose. Either move the CoL further forward by relocating the wings, adding canards or increasing the effectiveness of the control surfaces by increasing their size, deflection angle or distance from the CoM. (Or any combination.) Q: My plane violently veers off the runway. Why? A1: Your landing gear is misaligned. Make sure you don't have any toe-in or toe-out. Even a tiny, invisible misalignment can cause this problem. It can happen due to the curved shape of the part you're attaching the landing gear to. One way to fix this in the SPH is to select the rotator widget ("3" key), turn on absolute snap ("F" key), then wiggle the landing gear one notch out and back to parallel. This guarantees perfect alignment. A2: You are wheelbarrowing. Too much lift too far behind the centre of mass (CoM). The tail of your plane is lifted off the ground before the nose and it starts to fall over making it steer either left or right. A3: Your connections are too weak. Connections between parts are always a bit flexible. Use (auto)struts to shore them up. Q: Do I have to bring those science experiments back? I left them on the Mun and didn't get credit for reading them. A: No, all you need to bring back is the experiment data. If you have Astronaut Complex 2, you can get out of your ship. Once outside, get near the experiment, right-click it and remove the experiment data. Then get back in the ship and the experiment will be stored. You can also run the experiment again. Doing this over and over can get you a lot more science on a mission than you were getting before. With the release of KSP v1.2 a new part was introduced; the Experiment Storage Unit. In addition of storing science like any other crewed pod it can also be used to 'pull' all science data into storage. NB. The Goo canister and Materials bay are single use experiments. After data removal (through EVA or transmission) the experiment will be inoperable. To use it again you will need a Scientist or Lab to clean/restore it. Running KSP with mods / add-ons Q: How do I install a mod? A1: Download your mods from Curse, Spacedock, Kerbaltek or any other source you desire. Most mods come in .zip format. Mods will have to be installed in the GameData folder. Search for the GameData/ folder and open it. At the dame time open the .zip you downloaded. Some mods already contain a GameData/ folder. If yours does, open it. Drag and drop the contents into the GameData/ folder. Here's a useful discussion about the details. A2: As an alternative to this manual installation, there's a utility called CKAN that some folks like to use, which is an automated "mod manager" that takes care of downloading, installing, and updating mods for you. (Not all mods are available on CKAN-- it's up to the mod author-- but many are.) Q: I'm looking for a mod that <does thing>, how do I find out whether there is one and what it's called? A: Best way is generally to post a question in the Add-on Discussions forum. Q: I have a question about a particular mod. What's the best way to get help? A1: Usually the best place is to find the mod's release thread in Add-on Releases, and then ask there. That's where the expert users (and author!) of the mod generally hang out, so it's usually the best place to get answers. If your question happens to be a "tech support" kind of thing (e.g. "it's not working!" or "I keep getting a bug!", etc.), then you might want to review the How to Get Support thread, beforehand, for an idea of what kind of information people are likely to need from you. A2: Alternatively, you could just post your question in Add-on Discussions or Technical Support (modded installs) as a new thread. Usually you get more "bang for the buck" by posting in the mod's thread, though.
  18. I finally managed to build a reasonable craft for Eve Space Program that can get to Eve orbit with about 1300-1400 m/s dV left. In career mode, with only Tier 3 and 4 parts. Craft file here, uses OhioBob's Eve Optimized Engines. After several attempts, my best effort is in this video here. The biggest challenges of the current incarnation of the Eve Space Program mod are the lack of biomes outside of the KSC, and the distance of most survey contracts; the KSC is a quarter of a world away from where the game puts those surveys. This leaves part tests, science grinding around KSC, and a full fundraising campaign strategy (25% of reputation going to funds) to pay for building upgrades. Otherwise I'd be using a lot better parts for this craft. As it stands, the only remaining source of decent science is Gilly, and I can't reach that and get back on 1400 m/s. I didn't do any dV math really; just tried plotting to Gilly's orbit needing 1425 or so m/s, and came up short just by 20+ m/s. That being said, I remember someone saying that ascending from Eve's surface to orbit needs a launch profile that goes straight up for a large part of the ascent, then starts the gravity turn very high up. With this craft I find I can start my turn just around 20 km, and also before staging away the last of the Adam engines and going to my first non-EoE; the Swivel, close to 35-40 km. Then some careful throttling and I can get to about 1400 m/s orbit speed before staging away the Swivel and going to my Terrier, finally closing my orbit with maybe 2/5th of my fuel. What would be a better ascent profile for launching into Eve orbit? Where to start turning away from vertical? At what altitude and at what speed should I have a pitch of 45 degrees? If you try this craft, note that Eve Space Program's launch pad is only at 450 m altitude, and I'm using tank priorities and decoupler fuel crossfeed to use a hybrid of onion staging and asparagus staging, so watch the tank levels on ascent. [Update 15 APR] There's so much good advice here I can't mark any one answer as correct. I upvoted all of the good answers and gave out likes.
  19. I've been doing a lot of testing with landers this past week, and would like to share a landing technique that I've figured out in the process. Not sure if it's already commonly used or has a different name. If so, please let me know. The two most common landing techniques are the "suicide burn" and "zero descent rate" approaches. The suicide burn is a reverse vertical ascent-then-circularization burn. On the plus side, it can drop you in the neighborhood of where you want to be, but relies on perfect timing, high thrust to weight, and is hugely wasteful of fuel. The zero descent rate approach is the most efficient approach and doesn't require a high thrust to weight. It's the reverse of an immediate prograde burn to orbit. But on the downside, it's highly inaccurate AFA final touchdown point, and may smack you into terrain if you're not careful. I call this the "reverse gravity turn approach" and it has advantages over both of these techniques. It has medium efficiency, works with low t/w ratios, is very easy to execute, and will drop you right where you want to be with no fuss. I will demonstrate what you need to use this technique, starting with the vehicle: We are going for Tylo in this example, and this is our lander. DV is twice the "perfect" DV for Tylo according to WAC's DV chart In the case of Tylo, it says 2270 m/sec, so we'll double that to 4,540. T/w should be at least 1.2 at the body you wish to land on. No harm in going a little higher to start with, but keeping a low t/w will make your touchdown less twitchy because you have finer throttle control.
  20. Hello there. I've been designing a LKO tourist vehicle, and my latest version has begun to hit some strange snags. Despite the COL being below the COM at all times, this rocket tends to flip over whenever I begin my gravity turn. Even the slightest nudge east causes it to spin. Any suggestions?
  21. I'm having some serious issues with rockets flipping right when I start my gravity turn. I didn't have this problem pre 1.0. I just recently upgraded to 1.0.5 and the issue started. At first I thought it was due to the fairings bug, but this last rocket has no fairings. Mechjeb has the same problems, only earlier in the flight. The only mods I have are KER/MJ. I also cannot figure out how to attach an image right now but this seems to happen with almost anything I design. Please help because this has become extremely frustrating. Thanks in advance. http://imgur.com/sXfZXTX
  22. Yes, there are a bunch of oldtimers who are going to moan and say "not this issue again!!?" Tough. Each new group of newbies needs to be exposed to the argument. If you don't want to see it, don't read any further. But I hope several of you will try to show me the error of my ways. @foamyesque & @Spricigo? So, I'm in the direct ascent camp. The gravity turn zealots make wild assumptions about how wonderfully efficient it is to do it their way. I say the gains are minimal at best, and it depends on whether you are calculating "efficiency" on the price of a kg to Munar or Minmus orbit, rather than deltaV. So let's try a competition. It only works if we all launch the same upper stage. So here's the one we are going to all use: http://www.virtualrealitytoursllc.com/pix/scan_sat.craft Here's a pic. Note the price = 16720 kredits. The rules are: you can add anything to the upper stage that you want to make it fly your way. You can try as many times as you like to be as efficient as you can. You can use MechJeb to fly it for you. Put the upper stage in (approximately) a 10 x 11.5 km orbit around your destination celestial body and report your total launch cost, the time it took to reach the destination, your remaining fuel, and the price per kg to reach that orbit. However, you may not remove anything from the common upper stage. Only additions allowed. Now, this is supposed to be a test of gravity turns. So SSTO spaceplanes are really not in the competition. But if any of you want to launch the upper stage as cargo in an SSTO and report the numbers, that would still be interesting. And I made it easy for you. I launched mine by eye. I didn't use any tools or maneuver nodes or anything. You can beat me by a bunch if I do that, right??! I even gave you a break on the time. I started a new game at Day 1, 0:00 and waited several hours for a launch window. Here's my launchable version of the rocket (note: grand total price = 30690 kredits): So my total cost to launch the upper stage was 30690 - 16720 = 13970 kredits. Proof that I got there -- and my mass in orbit = 7610 kg. Total flight time = 8 hours, 7 mins. With 675 fuel remaining. Cost per kg in LMO was 13970 / 7610 = 1.84 kredits per kg. And then I also did Minmus for fun. The numbers are almost identical. 1.85 kredits per kg. Total flight time (including waiting for window) = 6 days, 4 hr, 36 mins.
  23. So basically whenever i launch a rocket, E.G a rocket to haul a space station up into orbit, it tips over. After the roll, i initiate the pitch, but then quickly loose control and my space ship literally tips over facing the ground. I tried MechJeb, Manual flight, but nothing works. Any help would be much appreciated.
  24. Hey, How should optimal gravity turn look like? I mean when to start pitch and how much? I have my vessel at the edge of launch pad capabilities (mass 140 tons) and I count every m/s so I want to avoid pointless "pumping-up" my apogee (going to steep) or fighting through the atmosphere (going to flat). I saw some profiles on the internet but those are lacking precise values.My second stage burn is around 5 minutes.
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