Rune

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About Rune

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    Flight Director

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  1. Dude, you tamed Eve. And you did it using Rhinos! Mad math skillz there, many kudos deserved! Rune. Not seeing nukes in there was the most disconcerting thing of it all.
  2. Hi! Well, RCS blocks do have a few things to keep in mind. First, they are physicsless parts, IIRC, which means that, on their own, they generate no drag. Or rather, they don't generate drag on themselves, but they do add to the drag (and weight and so on) of the part they are attached to. Which means, you could probably exploit that, place them on a shielded part inside a cargo bay, move them outside with gizmos, and unless I'm mistaken you would have drag-less RCS ports. Not that I actually do such things, but it's the way I think that would work. Now, what I do, that's different. First, I eat the drag as a small inefficiency, just like I sometimes place parts for aesthetic purposes only. Once you design an ultra-efficient prototype, you can tape more stuff on to it, to make it also practical. And of course, I never use the four-way RCS block on spaceplanes. Temp. rating is a measly 1500°, and it looks very wonky in any case (IMO, YMMV, and all that). Instead, linear RCS ports can be hidden quite flush, and both them and the uber-powerful (and expensive!) Vernors have temp. ratings of about 2000°, which is much more reasonable to handle your typical reentry. Besides, you can try some weird ways of getting six-degree control authority that way, and some of those can actually tailor your RCS subsystem to you plane's actual moments of inertia on each axis (a long plane has big moment of inertia in the yaw axis, but a small one in roll). A few more parts than the 4x RCS blocks radially spaces 45° that we always use, but a nice change sometimes! Rune. Experimentation is encouraged.
  3. His won't be the only requirements met, good idea all around! Rune. Ain't feedback cool?
  4. If that does what I think it does... dude. That's complicated. How many independent craft while on operation? Rune. Totally useless, but in a very spectacular way.
  5. A lot of people bring this up when I talk about the RAPIER being the only sensible solution for SSTO... and it's completely irrelevant. We are talking about Single Stage To Orbit. Not Tylo, not Layhte, not Minmus, and not Duna. Obviously the RAPIER is not the best engine for in-space travel. The nukes are. So count your nuke as part of the payload fraction of your mostly-rapier-powered plane-thing, and you have yourself the longest-range single stages in the game (I am intentionally ignoring ions, because that is not the point I'm making). And if we are talking about SSTAnywhere and Vectors... well, I have this. No intakes. Rune. And I have an even better one without wings. But that's untested.
  6. Backup the backups. In triplicate. Rune. Close calls are IT's way of saying "when was the last time you saved everything to a backup disk?".
  7. I like the idea, but stability. It's the one thing that also irks me about ITS, how the heck do they control the attitude during reentry. The CG/CP positions must be very tightly controlled for such a thing (forget forcing things propulsively if you are trying to brake aerodynamically), and you have, at the very least, a cargo bay that might or might not be full. You need something ballast-y on the nose to balance the engines, but you need that to stay put and maintain its weight. Oh, and you need to account for varying fuel levels, or a tank at the CoM. And last but not least, it would be nice if the thing more or less stays rigid during reentry, which means it is capable of maintaining shape when empty and decelerating laterally at some 3Gs or more. Or with a full payload bay and doing the same, which would be more impressive, if you want downmass. I mean, if you can work it out without too many structural efficiency sacrifices, yeah, great concept. But I would like a full structural/thermal/aerodynamic load analysis before assigning a mass fraction to that stage, unless I use a "fudge factor" of about 2. So you'll excuse me if I take your numbers with a grain of salt the size of some metaphorical houses. Oh, and the thing about single-staging to the Moon and back from LEO... you are aware that is 6km/s each way, right? At least nine for the roundtrip, and that's with a high-velocity reentry directly from the Moon, several times harder than any LEO reentry. How much dV do you want to pack in this stage, again? Actually, as has been said already, high surface area is nice, because it lowers peak heating. A big ballistic coefficient is always nice on reentry. And if you can use "only" ceramics and high-temperature metallic alloys, you might have a reusable non-ablative heatshield like the shuttle. Which will be much safer because it sits on top of its first stage, not at the side and facing it. Rune. That being said, I believe reusable TSTO is doable, even in an economical way, at least for launches to LEO.
  8. Pretty cool! The Jool system really is the paradise of a good navigator, and the reason many of us end up learning how to grav-assist. And four moons without mid-corrections sounds sick! Well, braking into a Joolian orbit using Tylo may be much more common than it once was, but it's still a pretty big accomplishment! Think about it, in the real world, it took NASA until the seventies to use the trick, with Mariner 10, to get it to Mercury. And you learned how to do it with a videogame! So yeah, welcome to the club of people that think planning complicated maneuvers is fun. Rune. Any other navigators out there?
  9. Dudes, watch it a little, please! There is a person at the other side of all those notifications. Yes, he lied to people, and he got caught. Bad on him, but he must be feeling pretty excrementsty already. And it's not like he lied while running for an election or something! This is a game, and whatever benefits he can get from his youtube account, a pittance at most. I'm just saying, put things in perspective, even if you like your daily dose of drama. Rune. Be slow to anger, so that when you do get angry, it's for the right cause.
  10. Cool one! That's, what, RSS? Care to explain the particulars of the situation, so we can be properly awed? Rune. And perhaps learn something while we are at it!
  11. You are welcome! I had a feeling it was something like the node thing that was thwarting your efforts. One of those non-intuitive KSP things where it's not how you see it, it's how the aerodynamics model sees it. Rune. Always glad to be of help.
  12. Ever felt like Kepler and Newton where sitting on your shoulders, whispering as you plotted a maneuver? Maybe you managed to plot a course that seemed impossible, and got your kerbals back home with the last drop of fuel. Perhaps plotted three gravity assists with a single node? Circularized around Jool with RCS and Tylo to await rescue, because you had horribly misjudged your dV, but are a heck of a navigator? Well this is the place to show off those navigational skillz! It's amazing what this game teaches us to do, so let's show off our intuitive understanding of orbital mechanics, and those feats of orbital maneuvering that made us feel like we were the guys at JPL. I'll start with the one that prompted me to write this post, so you see what kind of thing I'm talking about. See, I was wrangling this asteroid, with not a lot of time (or engines), and I just managed to stop it at close approach, in a very weird 50º inclination (in my defense, I didn't see it until it came into kerbin's SOI, else I would have corrected the trajectory in solar orbit with plenty of time). Trouble is, the rock is about 1,700mT, and I only have four puny nukes on the ship tugging it. Even with a lot of fuel tank space for them, I can only get ~150m/s out of the tanks before I dry them and have to process more fuel, so I am limited in what I can do in a single burn. Changing that inclination and altitude by brute force, in any case, would take ages. So, what to do? Easy, just catch a ride on the Mun! I highlighted the important bits so you can admire the thing, plotted in all its glory. Just two maneuvers totaling 67m/s! And you can't see it from there, but take my word for it, the resulting orbit is not only a lot lower (16,400x78kms vs 39,300x9,800kms), it also has pretty much zero inclination (the game won't tell me, but I did the trick of moving the camera to make it coincide with the Mun's orbital plane). Yay me! I totally felt like like a pro when I plotted that. The key is that Munar encounter, where I fiddled with the node more or less by gut feeling until I got closer and closer to what I wanted (use a gravity assist to kill my vertical motion and thus make my inclination 0º). It came out to around 51kms altitude, so I could actually gone a bit lower if I needed more change in velocity. Turns out I also go out on a very useful orbit, where I can move into an aerobrake to go lower down, or use another Mun encounter afterwards to circularize at around the Mun's altitude, with further small corrections. Isn't it awesome what you learn to do in KSP? And it's all done by Mk1 eyeball, not even precise node! For completeness' sake, here's the "vehicle" I plotted this for, just before the very long capture burn that got me the initial "wherever it falls" Mun encounter. Tip: to make good maneuver screenshots, you can make highlights persistent in map mode by right-clicking on stuff (manuver nodes, Ap/Pe nodes and all that stuff), and move the PoV around without clicking with Tab. Rune. Now show me how you did it!
  13. As I said in the post @Angel-125 quoted, not only do they have one of the worst tankage ratios in the game (full weight/empty weight), they have horrible drag values. The short Mk1-Mk2 adapter, in particular, is murder. It has around... ¿four times? ¿more? Can't remember off the top of my head, but something horrendous... anyhow, several times the amount of drag of a similarly-sized Mk1 tank. And their lift values are nothing to write home about. Rune. Check the thing I said about aerodynamic data in context menus, it's very informative.
  14. Actually, SSTOing in 1.2 is so easy once you know a couple of rules, I'm pretty sure I can cover anything important in a single post: The key is to hit the right TWR and drag. Once you do that, the ascent profile is as easy as going in a straight line and switching the RAPIERs to closed cycle when appropriate! Basically, you go flat-ish at sea level until the RAPIERs hit the magic 400m/s (the point when their thrust curve gets to its sweet spot, and the RAPIERs continue increasing thrust as you climb), then just watch as your vertical speed increases as the planet curves down under you and you keep going in your straight line, until the air is thin enough that the RAPIERs start giving out. Can't be any simpler! You just have to make sure that your ship is able to hit those magic 400m/s at level flight at sea level, and the rest will take care of itself. And I seriously mean that, I need many more manual control inputs when grav-turning a rocket, than flying a SSTO to orbit, where I just have to take off and set the initial "climb". Since rocketry is all about ratios, here are a few for you: the optimum TWR at takeoff should be around 0.5-0.7. About 33% of your takeoff mass must be fuel (at least), and I usually budget about 400-500 LF units for the airbreathing climb, per RAPIER, with the rest being LFO mix. I only use RAPIERs, of course (they are the best by far, so why use anything else). And always remember that your upper limit of payload to LKO is up to ~50%, but 25% is much more doable with some aesthetics flair, or inefficiencies, or just plain margin. Small or big your design might be, those ratios will hold, so make sure to check the final numbers in your design, make a few divisions and multiplications if need be, and change things accordingly. You can't cheat physics! (I mean, you can, but it is cheating, and it's done with the cheat menu ) And the other half of the equation are aerodynamics. This is more of a "how the game engine likes things" kind of thing, in order to be able to hit those 400m/s, with a TWR as low as 0.4 (but normally a bit more), to have that nice >25% payload ratio. But some simple rules will help a lot: -Leave no open nodes. Front or back, that's important: no matter how it looks, if you have an open node somewhere, the game thinks that is a flat surface against the wind. The drag will be horrible. -Also avoid unshielded surface-mounted stuff. These days, it pays to put everything inside cargo bays and/or fairings. You can check if a part is being shielded or not (and how much drag it gives) with the debug menu, by enabling the aerodynamic values to be displayed int he right-click menu. The arrow visualization tool is crappy, and will mislead you. This will teach you a lot, if you use it. -Use just the intakes you need. Frontal surface is the main thing that will limit your drag, having more intakes than absolutely necessary will increase your drag without giving anything in return. One shock cone per two RAPIERs, or a single precooler per RAPIER, is more than enough. Yeah, the ideal designs usually turn out very, very long and skinny that way. That is why we end up going to Mk3, for the added diameter with the same frontal surface (after a few adapters). -Mk2 fuselages are crappy. If you want to build Mk2, make sure your TWR is above 0.6, and that will hit your maximum payload, since you still have to be >25% fuel at takeoff, and you need proportionately more engine weight. The best drag/tankage ratios are the rocket parts, with Mk3 a close second. But Mk2 is still perfectly doable, of course, just with a lower payload fraction. -Wings are necessary for flight, but dead weight in the climb to orbit. Less is more, but you have to have enough to take off when full and get to that level speed run at sea level. BigS wings are cool, because they double as LF reservoirs, and thus their mass hit is smaller (even though as fuel tank only, they are rather crappy). Rune. Yup, that's pretty much it, the rest is just making it stable and capable of taking off, but that's airplane-building.
  15. My phone does weird things. Disregard! (And delete if appropiate).