Snark

So, your real problem here isn't the Vernor engines-- it's that your craft is not aerodynamically stable. When you're taking off in the thick soup that passes for an atmosphere on Eve, aero forces are king; they're so large that they swamp everything else, and a few Vernors wouldn't help you even if they were working properly (which they won't be, at those high pressures). The problem with flipping rockets is basically the same problem as if you try to throw a badminton birdie with the "feathers" end forward: the center of mass needs to be in the front. This is a fairly common problem with Eve landers. You don't want the ship to fall over when it's standing on the surface, so for stability, you generally want it to be low and squat, with the center of mass as low as you can make it. Unfortunately, that's precisely the opposite of what you want for stable flight when you're ascending back to orbit: to climb up out of the atmosphere, you want tall, and skinny, and as top-heavy as possible, with the CoM near the top of the rocket. (Tall and skinny to reduce drag; high CoM for aerodynamic stability.) Adding fins to the bottom of the rocket can help... but the effectiveness of fins is directly proportional to how far behind the CoM they are. So if you have a rocket with a CoM down near the bottom, adding fins on the bottom isn't really going to help. So, what can you do? Well, a few things. Don't make your lander too low and squat. The taller, skinnier, and more top-heavy you can make it for ascent, the more efficient and stable it will be. It can't be too skinny and top-heavy, of course, because then it would fall over when you land, which would ruin your whole day. But don't make it any lower or squatter than it has to be. Make sure the front (top) of your craft is as streamlined as possible. Nice and pointy, avoid anything draggy up there. Don't start your gravity turn too soon. The hardest, most grueling part of an Eve ascent is those first few kilometers climbing through the soup. By the time you get above 11 km or so, the atmospheric density is down to Kerbin levels and it's not so bad; but those first 5 km or so are just murder. During that part of the ascent, you're not trying to build up lateral speed for orbit, you're just trying to muscle your way vertically out of the soup as fast as you can. So here's my advice: For the first few thousand meters of ascent, set your SAS to "hold mode" and don't try to turn at all, just climb perfectly straight up. Here's why that helps: In "hold mode" when the navball is set to "Surface", what SAS will do is point you directly straight up. SAS has faster reflexes than you do, so it'll do a pretty good job. If it can hold you very close to perfectly straight up, then that means that even if there is some instability in your design, hopefully your engine gimbal, control surfaces, and reaction wheels can compensate for a while. Furthermore, precisely because that part of ascent is so brutal, you're gonna burn a lot of fuel, meaning that your big heavy boosters down on the bottom of your craft will be dumping mass and getting staged away-- which will raise your CoM and make you more stable. Hopefully, by the time you've climbed above 10 km, your CoM will have moved upward enough that your craft will be more stable and you can start your gravity turn without flipping out. Use active fins. Use fins that are active control surfaces, such as the AV-R8 winglet. These really help a lot with aerodynamic stability. However, be aware that until/unless your CoM raises high enough above them, they're not going to help you much, thus the advice above about not starting the gravity turn too soon. Climb fast, but not too fast. The higher your TWR and the harder you accelerate, the lower your gravity losses will be, which is generally a good thing. However, if you go too fast too soon, while you're still low in the atmosphere, then aerodynamic drag will build up really fast, and you can end up losing more to aero drag than you save on gravity losses. Furthermore, if your craft is aerodynamically unstable for the first part of ascent, then hitting too much drag too soon can overpower SAS as it tries to hold . So, what's the right balance? Skipping over a bunch of math, basically it works out that the optimally efficient vertical ascent is when you're traveling at terminal velocity the entire time. What that means is that you want a (local Eve) TWR that stays as close as possible to 2 while you're on the initial vertical part of the ascent; don't go higher than that. Since Eve surface gravity is 16.7 m/s2, that means the ideal acceleration power of your rocket during that part of ascent is double that, i.e. 33.4 m/s2. Lower than that, and you'll be wasting fuel to gravity losses. Higher than that, and you'll be wasting fuel to aerodynamic drag, and also making your instability problems worse.

Congratulations on your success! (And welcome to the forums.) Would you like to post a picture of your plane so we can admire it? (How to do this: Take a screenshot with F1. Post it to some public image sharing site. Any will work, but most folks use imgur.com because it's easy to use and doesn't require you to make an account. Once the pic is posted there, just right click on the image, choose "copy image location", and then paste that URL here in the forum and it'll be automagically converted to an in-line image in your post.)

Some content has been redacted and/or removed, due to folks making various personal remarks about each other. Folks, lively debate is fine-- but please don't let things become heated to the point of making personal remarks. And please remember that this is the "Suggestions" subforum, meaning that literally everything posted here is an opinion, pretty much by definition. I assume we all know what an "opinion" is, but it would appear that perhaps a refresher is in order: People have different opinions. And that's okay. (For one thing, if we all had the same opinion, then the forum would consist of people just sitting around agreeing with each other and would be a lot less interesting, don't you think?) Because of this, it means that any opinion you post, people are going to disagree with you. And that's okay, too. Therefore, a brief guide to what is or isn't okay: It is okay to... address the post (not the poster), i.e. respond to the idea they're proposing. E.g., say "I like / agree with <opinion> because <reasons>", or words to that effect. say "I dislike / disagree with <opinion> because <reasons>", or words to that effect. say "I like <different idea> instead, because <reasons>", or words to that effect. It is not okay to... make personal remarks (i.e. don't address the poster) insult people take out your anger on people because you're annoyed that they disagree with you tell other people what they should or shouldn't do Please remember that everyone has a right to their opinion, and nobody is in a position to tell anyone else that "my opinion is better than yours". Everyone is entitled to their own opinion, because they're simply stating what they like. Arguing about opinions is as silly as arguing which flavor of ice cream is better, vanilla or chocolate. (Chocolate.) Please remember that we're all pals here, and that we have come together as a community because we all really, really like KSP, and therefore are passionate about it, which is why our opinions are strong. We agree that we care about KSP, even though we disagree about aspects of what we like. Let's hold on to that, and remember to keep things friendly, and not make it personal, please. Unlocking the thread. I trust we can comport ourselves like civil adults? Thank you.

Hi @BonsaiDen, and welcome to the forums! We're sorry, but we've had to snip the log file. Please don't past gargantuan swaths of text into the forum. Even if it's "hidden" in a spoiler, people's browsers will still download the entire contents even if the person doesn't expand the spoiler, and this can cause all sorts of problems for people (especially folks on mobile browsers-- it can really jam things up). Posting logs is a great idea, but please don't do it here. If you've got a large file like that, please post it to some third-party sharing site (there are lots of free ones around the internet), and then post a link to it here, instead. That way, the folks with the bandwidth to help you can do so, and the folks who don't, can just skip the link. Again, welcome aboard!

Some content has been removed. Folks, it's fine to have a lively debate. But let's please keep it friendly, and not descend to personal remarks. The following points are self-evidently obvious, but it would appear that perhaps a refresher may be in order: People have opinions. Not everyone has the same opinion. That means that some people will have a very different opinion from yours. And that's okay. You are not in any position to tell anyone that their opinion is wrong, or that yours is better than theirs. Because they're just opinions. It is, of course, fine to explain why you have a different opinion from someone else. But please do not do so in a way that's insulting to others. Naturally, just because you explain the reasons for your opinion doesn't oblige anyone else to agree with it. Similarly, if someone disagrees with your opinion, it's entirely inappropriate for you to take it personally. It is never appropriate to make personal remarks. For example, claiming that someone else doesn't understand things as well as you do. Please address the post, not the poster. I trust that we can all comport ourselves like civil adults? Thank you for your understanding.

Fair 'nuff... but this conversation is from over three years ago, and everyone involved has presumably long since moved on. Accordingly, locking the thread to prevent further confusion. If someone has a question or suggestion about KIS, probably the best place to ask would be in the KIS thread.

Moving to Gameplay Questions.

Moving to Gameplay Questions.

Some content has been redacted and/or removed. Folks, please don't troll or mock others. This is a friendly community and we're all pals here (right?), and it's never okay to try to build yourself up by putting someone else down. If you see someone making an argument that you think is silly or wrong, then by all means dispute them-- friendly debate is welcome. But please, do so in good faith by explaining the reasons you think they're wrong, not by trying to ridicule. It doesn't solve anything and just makes the forum less pleasant for everyone. Or, if you think making a reasonable counter-argument would be too much trouble and can't be bothered, then just stroll on by. Unfortunately, there was also some unavoidable collateral damage. Some posts by blameless participants also needed to be removed, as they were innocently responding to the removed content and their posts no longer made sense with the referents removed. To those thus affected, we're sorry. Thank you for your understanding. Unlocking the thread now-- I trust we can all play nicely?

Well, first and foremost, of course, is that if it works well for you and does what you need it to do, then that's all that really matters. That said, I'd suggest that you could do with significantly lower TWR in 3rd stage. If you've got over 2500 m/s in your 2nd, then that means by the time the 3rd stage kicks in, gravity loss is simply not a thing anymore. You could have a TWR of 0.5 or below-- even 0.25 would probably be fine-- and save quite a bit on engine weight. Also: If your first stage is currently SRBs-only, then depending on how you have them arranged and what engine you have on your 2nd stage, you might be able to squeeze some extra performance out of this, with just a small design tweak, as a sort of "poor man's asparagus." Details in spoiler, if you're interested.

If you look at any given contract in Mission Control, it'll say when the contract expires (usually within a few days). If you don't accept the contract within that time frame, then it'll go away and be replaced with another one. So it varies, but "several days" is typical. The exception is the "World Firsts" contracts, which don't expire. They hang around until either you accept & complete them, or supersede them (by fulfilling their requirements outside of the contract).

"Reasonable" launchpad TWR is generally in the 1.2 to 2.0 range. You can fly well, and "efficiently", within that range-- though the design strategy would differ depending on where in that range you fall. Lower TWR means higher gravity losses, which is less "efficient". So a higher TWR is "better" in that regard. But... higher TWR also means bigger engines, which are more expensive than fuel. A lower TWR rocket can get away with cheaper engines, it's just going to have a bigger launchpad weight and have a lot more fuel to burn. It's "wasteful" in that sense... but it's not as though KSC is gonna run out of fuel, and fuel is cheaper than engines. Lower TWR rockets can also get away with being less aerodynamic than high TWR, since they get up to a higher altitude (where the air is thinner) before they get going fast. So if you have an awkward payload that's difficult to streamline, a low TWR can be useful. In other words: both high TWR and low TWR can be a valid design philosophy, you just gotta suit the rocket design to the TWR. You generally don't want to go any lower than 1.2, because then your gravity losses blow up. You also probably don't want to go much higher than 2.0, since then aerodynamic losses really go through the roof, and you end up losing more to those than you save in reduced gravity loss. Also, TWR > 2 generally means you're probably carrying way too much engine, meaning a lot of unnecessary dead weight, which will eat into your dV. Note that all of the above discussion is for the launchpad. Upper stages generally have lower TWR, because they're going mostly horizontally and gravity losses aren't much of a thing. (For my own designs-- which are usually three stages to orbit-- I go for TWR 2.0 for the launchpad, 0.7 to 1.0 for the 2nd stage, and something really low for the 3rd. Doesn't mean that's some sort of "ideal", it's just how I roll.)

Yes, it does take staging into account. Another new feature of the burn indicator, which came in at the same time as the "percentage" control that you started this thread with, is that if the burn will extend across more than one stage, then the "dV meter" will have a little line drawn on it at the point where staging needs to happen. So, one more indicator of "stage awareness".

Moving to Gameplay Questions. It's from the base game, and is a feature that got added a few KSP versions ago. What it does is exactly what @jimmymcgoochie said. And yes, the default setting of 50% is, in general, the best choice. It means that the countdown timer will be arranged so that half the burn happens before the node and half is after.

It seems to me that Nertea has given a pretty firm "no" here with respect to Making History, and was admirably polite about it, too. Even gave his reasons, though he was under no obligation to do so. I also note that he's been doing this for a while and knows his business pretty well, so I think that it's safe to assume that he's aware of his options and has reached his conclusion (firm "no") taking that into account. Accordingly, considering what he's given us all (and continues to give us), I'd like to think that the polite thing to do is for us to take "no" for an answer. Yes, I realize that a lot of folks really like Making History and would love to see an overhaul there. But since anyone else who cares enough could do the work themselves and release it, perhaps best not to hector the guy who's doing plenty of other sterling work, for free, and who has already indicated he's not interested.

Yeah, that looks pretty close. I would think that you'd probably also want to get rid of this part, @ScaledVersion { %Material { texture = JoolBiomes/JoolColor.png } } ...but if you've found a combo that works for you, go for it.

Ah, okay. In that case, moving this topic over to Add-on Discussions, since it's a problem with a mod and not with the stock game. Note, however, that if you have a problem with a particular mod, the best place to ask is generally in the mod's release thread under Add-on Releases. Have you asked your question in the Global Construction thread?

Fair enough, but I still can't tell for sure-- are you commenting about some behavior that's specifically about how the mod behaves? Or are you just running into difficulty with the stock docking ports, and you just happen to be using the mod? (It kinda sounds like you may be talking about a problem with the mod... but you keep mentioning "docking" which is a thing in the stock game, so I can't quite tell.) (I ask because Gameplay Questions is a good place to ask about the stock game-- problems with mods themselves have other places to address them, but I didn't want to get into that without knowing whether you were specifically having a problem with a mod itself.)

Hi @DareDrop, I'm having a little trouble understanding what you're referring to-- "container"? "orbital workshop"? Are you referring to issues with a particular mod, or something?

It does not. Where the engine is, relative to the CoM, does make a big difference to how effective engine gimal is at holding bearing-- that's because it has a bigger lever arm to work with if it's farther from the CoM. But it doesn't matter where reaction wheels are. At all.

This is not a bad plan, in this case, since the target orbit is so high. If you're in an extremely eccentric orbit with an Ap waaaaay up high past Minmus, and a Pe down by Kerbin, then your orbital velocity at that point will be so low that the plane change will be very cheap. Also cheap at that point to raise your Pe. And then doing a burn at Pe to drop your Ap will also be cheap, since your Pe is still really high. (This would not be a good plan if the target polar orbit was much lower, like a couple thousand km, because then #3 and/or #4 would be more expensive.) The alternate approach would be to just launch directly to a polar orbit. You'd launch just slightly to the west of due north. (The slight westward bearing is to compensate for Kerbin's rotation. If you actually launched due north, you'd end up in an orbit that is almost-but-not-quite polar and would need to do plane correction later.)

That's... not how it works. The location of reaction wheels has no effect on their effectiveness. Detailed discussion here, for anyone who's interested. TL;DR is that it doesn't matter where you put the reaction wheels. Actually, it's the other way around, in terms of aerodynamic stability: top-heavy is good for stability. It's being bottom heavy that can be a problem, though it's not clear to me whether the OP's problem here is aerodynamic instability versus just having an autopilot mod that has issues with the TWR of the craft. I kinda get the impression that it's more about mod behavior than aero stability per se. Where's the CoM of the second stage? It looks pretty bottom-heavy to me. If the CoM is way down near the bottom, then adding fins there won't help much-- they won't have much lever arm to work with because they'll be too close to the CoM.

Glad you like it. ...Out of curiosity, is there any particular reason you've got that 88-88 stuck on there, as well? It's not really doing anything. Is it just for looks?

Moving to Technical Support.

Yeah, what happened here is that they changed the part from being a mere structural adapter to being a fuel tank. KSP fuel tanks tend to be heavy: they typically have a dry mass 1/8 as much as the amount of fuel they can hold. So for gameplay balance, it's appropriate to increase the dry mass of the part. What you're running up against is that you want to use the part as a simple structural adapter... and using an empty fuel tank for that (which is what the part now is), is not very efficient. Interestingly, the old (lightweight, structural-only) version of the part is actually still in the game-- the newer version is actually a different part, not an alteration to the older part. (This is what they typically do, when they alter an existing part, since they don't want to break backwards compatibility for folks whose games already have ships with the older part in them.) The old part-- i.e. the one that you want-- hasn't been deleted, it has only been hidden. And it's possible to un-hide it, if that's what you want. Assuming that you have ModuleManager installed, then all you need is a snippet of config to un-hide the part and make it visible in the VAB. I believe that what you need is this: @PART[Size3to2Adapter] { @TechHidden = False @entryCost = 8800 @category = Structural } ...I haven't actually tested that, but I believe it ought to work. Just create a new text file somewhere in your GameData folder, whose name ends in the ".cfg" extension, and paste the above text into it. Assuming that you have ModuleManager installed, then the next time you start up KSP, I believe you ought to be able to see the old lightweight part show back up in the VAB. A cautionary note: Just because Squad has chosen to leave the obsolete version of the part in the game up to now, doesn't necessarily mean that they'll leave it in there forever. Maybe they will... but it's also possible that in some future version release of the game, they might eventually delete it for good. If they ever did that, then any ships you have that include that part would break (be unplayable, the game wouldn't be able to load them), either in the editor or in flight. My guess is that probably you'll be fine for a good long time, but I don't actually know that, so caveat emptor.