GoSlash27

All this, and you should probably add some parachutes as well to help simulate the the density of Eve's atmosphere below 10 KM. If you're looking to test your lander/ ascent without building an analogue, the easy solution is to hyperedit it to Eve orbit in sandbox and give it a go. Best, -Slashy

Actually, using KER would not be preferable since it would require you to actually build the vehicle just to see if your adjustment is workable. Only takes a few minutes to run the equation by hand, whereas it would take a good deal longer to fire up KSP and actually build the vehicle. As a bonus, I don't actually have to be sitting in front of my home computer to design a mission. That means that when I *am* playing KSP, I'm spending less time mucking about in the VAB and more time flying. Again, not telling you that you "should" do things any way other than the way you want, but doing the math gives players very powerful advantages that KER can't match. No way I would be able to build vehicles as cheap and efficient by trial and error in the VAB. As a bad analogy, mods like KER are like a basic set of hand tools. Nuthin' wrong with using them if that's your preference and you can get by just fine with them. But the rocket equation is like a machine shop. People who learn to work with it can create much more powerful tools than the ones that come in the KER kit, which allows them to do things they couldn't otherwise do. Not everyone wants to be a machinist, nor should they... but those who express an interest in how the machine shop works should not be dissuaded from messing with it. Best, -Slashy

Actually, it's the opposite. Calculators and spreadsheets will give you incorrect answers to a very high resolution. Slide rules will get you within .1% of the correct answer and not tell you where the decimal is supposed to go. Best, -Slashy

You must've missed posts 17, 34, 45, 62, 74,79, and 81. If you'd read them, you wouldn't be asking this question. -Slashy

Wanderfound is "the man" for interplanetary spaceplanes. No, you don't have to intake- spam to make it work. Really, you can lift spaceplanes at any scale economically into orbit with just .015m^2 of intake per engine. You have engineering challenges that come with making bigger spaceplanes such as asymmetric starvation, floppy wings, etc, but other than that, it all scales linearly in my experience. Best, -Slashy

No, it will, if done right. Doubling the mass of the spaceplane means doubling the fuel for your LV-N. Actually more than doubling it, since a lot of your core components like the cockpit and LV-N don't get doubled. But before any of that can happen, you have to be able to double the mass of a spaceplane without losing your gains. You double the wings, double the engines, double the intakes, and double the payload... but almost all of that additional payload is fuel for your LV-N. Best, -Slashy

It doesn't. Ignore DV for your jet- powered portion of the ascent. You just want 150 units (one LV tank) of jet fuel per turbojet engine. For the insertion portion, you will need to budget 150 m/sec from your LV-N, which is the engine you will be using for an interplanetary spaceplane regardless of size. Best, -Slashy

If you're not suddenly losing yaw control, then it's not the problem I figured you were dealing with. But yeah, not scaling the wings, engines or intakes linearly would cause you to run out of steam early. Having to go to rockets early will erase any gains you might have from scaling. Best, -Slashy

We're getting somewhere Are you still hitting the same speed before you have to go to rockets, or are you going to rockets earlier? Are you losing yaw control and spinning out?

^ There's that, but I'll set it aside. Solid spaceplanes scale. What is going wrong with your spaceplanes that they're not scaling? What difficulties are you running into with big spaceplanes that you're not seeing in little ones? -Slashy

That is actually the core of the most fun part of the game for me; knowing when to "ad-lib" from the script due to special circumstances such as the ones you've provided here. In those cases, having knowledge of how the math works from experience and being able to work the problem on-the-fly on a napkin is actually *more* valuable to keeping you on track, not less. You just say, "yeah, that engine is better, but I have to use this one because (insert reason here), and I'll need *scribble, scribble* this many engines and this tank to pull it off." Then you just plug in the numbers and move along. That's actually how I made my 52 ton Eve package work; the maths said I needed to go a different way for best results, but the aspect ratio wasn't workable and I didn't have a spreadsheet for the situation. Thankfully, I had experience working the math the hard way. KER wouldn't have helped me there. Best, -Slashy

Honestly, not so much IMO. The game is already as difficult as it needs to be in stock form. Doing that would make the game less enjoyable for everyone, whether they are personally doing the math or relying on a mod to do it for them. Doing that would force me to either a) pad my requirements to cover the errors or gin up ways to pin down the correct numbers on my own. Either way, less time spent making rockets go all 'splodey'. Best, -Slashy

^ What he said. In addition to reducing the leverage needed to get the nose to rotate and increasing the force you have available to get the plane to rotate, don't forget to have the nose higher so that the wings aren't planting your aircraft into the runway. Best, -Slashy

*You* personally didn't and I never claimed that *you* did. *You* merely raised a point in this thread and I responded to it. If the shoe doesn't fit, then just chuck that sucker aside. And no, such things cannot be addressed in the threads in which they are raised without hopelessly derailing them, which is why this thread is here. Best, -Slashy

Nobody's saying you have to. *You* are free to play the game in whatever way you enjoy it the most. All's I'm sayin' is that the fact that *you* don't want to mess with the math (which is perfectly valid) doesn't mean you should tell others to avoid it if that's what they're interested in. Best, -Slashy

With that correction, I am 100% fully in agreement with everything you've said here. I have no interest in trying to convince others to mess with aspects they'd just as soon not be bothered with. I'm just saying that we also shouldn't discourage people from messing with aspects that they *want* to be bothered with. Best, -Slashy

Expanding on that thought (and this *is* definitely bragging, but dammit... I'm proud of it!)... My first Apollo style moon shot was accomplished without any spreadsheets at all. I optimized the design on paper and ran all the calculations using a slide rule; a Pickett 120 like this one: Did I enjoy doing that? You bet I did! It's one of the neatest things I've ever done! Best, -Slashy

Honestly, I allowed myself to get sucked into the discussion of which approach is "better" and that wasn't the point of why I brought this up. You set your own criteria for which is the best way to play the game for you. It's not my place to dictate that to you. Me *personally*, I get the most enjoyment from this game by achieving the most difficult goals in the most efficient manner possible with no guesswork, trial and error, or failures. Turning the tables on that thought, would you find the game more enjoyable by not using KER and having no idea what your DV is, or less enjoyable? Some people actually prefer playing that way. Your mileage may (and should) vary Best, -Slashy

^ A very simple example to illustrate the point... You are designing a mission to Duna and currently assembling the transstage. Your payload for this stage is 35 tonnes and you need to impart 1,500 m/sec at 1G acceleration. To keep it simple for this example, we will just use 1 stage to do this job and assume vacuum Isp. The question: What combination of parts will accomplish this task with the minimum stage mass? KER won't answer this for you. How long will it take you in the VAB to answer this question? A spreadsheet can answer this instantly, tell you exactly how many engines to use in the stage, how many tanks of what type to use, and tally up the stage mass and overall mass to apply for your booster stage. Best, -Slashy *edit: double ninja'd!*

The difference in this approach is that you can simulate the process of trial and error in the VAB that would take weeks or even months instantly with a spreadsheet. Rather than simply telling you what a rocket you have already built can do (which is all these mods are capable of) it can instantly tell you far more important things, such as "which engine is best for this stage", Exactly how much mass this stage will have using the selected engine, and exactly which staging scheme is the least massive, or cheapest, etc. Learning/ applying the math and using spreadsheets instead of mods allows you to design an optimal vehicle for a mission in a matter of minutes before you even get into the VAB. No trial and error, no assembly and disassembly, no nuthin'. Just plug in the requirements, pick your options, and you know exactly what you need to build before you start. That's the power of using the math instead of a mod. Best, -Slashy

Well, thanks... I guess :/ Inasmuch as it did spark a discussion, it wasn't the discussion I was intending. The relative merits of doing the math yourself vs. letting KER do it isn't the point. How other people prefer to play the game isn't the point. I'm just saying that calling the process "hard" and steering people towards a mod is kinda absurd. It would be the same thing if someone asked a question about flying planes and people were to say "flying planes is tricky. You should just get a mod with an autopilot". Uhh... flying planes really isn't all that tricky; a lot of us do it all the time. Not bragging, not belittling those who have trouble flying planes. Not telling everyone else that they shouldn't use autopilots. Just sayin' "Maybe people who are asking for help in piloting would be better served with assistance in learning to fly a plane than they are by being immediately steered towards an autopilot mod." Best, -Slashy

All of this to get this^ point, which is what I've been trying to say. Thank you! -Slashy

"Only", he sez... Great job! Best, -Slashy

Tsevion, Sorry. Couldn't pass up the opportunity Cheers, -Slashy

I understand and appreciate that, but it's not what I'm saying. I'm not a super math whiz and all the folks who have piped up in this thread and said it's not hard are not super math- whizzes (presumably). It just plain doesn't take a super math whiz to run this equation. And yet... whenever somebody posts a help thread asking about DV, somebody will invariably come along and post (and this is a *direct quote*) "Calculating delta V is very tricky and it's best to get KER." I would cite specific examples, but I believe it's bad form to call out other members personally. My point is that it's really not "tricky" at all and it's doing a disservice to the guy asking advice to tell him it's hard and he should get a mod to do it for him. People learn by doing, right? Why dissuade somebody from attempting to learn? As several people here have pointed out, doing the math themselves opens up possibilities that they just plain wouldn't have with mods. Best, -Slashy