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Kerbal Space Program

Discussion in 'Space Games' started by DarkUnderlord, Sep 21, 2012.

  1. DarkUnderlord Professional Throne Sitter

    DarkUnderlord
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    After having loads of fun blowing up spaceships in the demo, I'm trying to buy this but the website is almost as bad as the Codex. It's being a slow-ass piece of shit that won't even let me complete the buying process.

    http://kerbalspaceprogram.com/ (Sometimes, it won't even work!)

    It's making me wonder whether it's not actually worth it. Anyone else got this and had fun with the current update?
     
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  2. potatojohn Arcane

    potatojohn
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  3. Spectacle Arcane Patron

    Spectacle
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    Designing and launching rockets in KSP is pretty fun, but we need some kind of navigation system. As it is getting the right trajectory feels too random.
     
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  4. Rhalle Magister

    Rhalle
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    I haven't played it since the first thread, but there's lots more to the game, now, right?
     
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  5. potatojohn Arcane

    potatojohn
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    Try the interplanetary calculator: http://ksp.olex.biz/

    also, mechjeb.
     
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  6. Turjan Arcane

    Turjan
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    This thread brought me to at least download the demo. Suddenly, it was 3:30 am. My work performance suffered somewhat.
     
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  7. DarkUnderlord Professional Throne Sitter

    DarkUnderlord
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    I finally got their website working long enough to be able to buy this today.

    Yeah, I'm finding that. Building rockets and getting into Orbit is actually the easy part. The hard part is figuring out quite when and where exactly to fire your rockets - just at the right time to get the right angle that gets an orbit that's not too slow but not too fast.

    I can reasonably consistently get into Orbit around Mun but so far, I'm having a bitch of a time slowing down enough so as to actually land on the damn thing.
     
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  8. potatojohn Arcane

    potatojohn
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    I imagine the release version will have some sort of trajectory tool like orbiter's transx where you can input time of departure, delta-v, etc and it shows you where you'll go.

    How so? Try to keep your speed at 1/100 of your altitude. I.e. 600m/s at 60km, ... 1m/s at 100m.
     
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  9. DarkUnderlord Professional Throne Sitter

    DarkUnderlord
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    But that requires fuel to slow down and usually, I've used all my fuel trying to get into damn orbit with the thing because I have no reference point to know which heading I should use to get to the Mun efficiently once I'm in space (beyond "pointing at the thing" which is less than optimal).
     
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  10. Hamziz Learned

    Hamziz
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    I carried over a lot of skills and intuition from "Orbiter" (a painfully realistic space flight sim), and might be able to help you a bit:

    1. You always want to launch straight upward, until at least around 20k ft, then s-l-o-w-l-y turn through the second half of your launch burn to heading 90 degrees (straight east). If you get the timing right, you can have a nice, neat circular low kerbin orbit without having to do any adjustments. The rotation of the planet is the same as earth, and heading east gives you a speed boost that helps get you into orbit by burning less fuel.

    (what follows is a very rough description of a hohmann transfer - you can look it up for more details and a better explanation)

    2. After you've established a low, circular (even, as in your apoapsis and periapsis are roughly equal) orbit around Kerbin, wait until your craft is on the opposite side of the planet from the moon you want to get to. That is to say, you want kerbin to be exactly between you and your target.

    3.NOTE: When doing orbital transfers you always want to burn facing either prograde (the direction your ship is already traveling), or retrograde (the exact opposite direction). This is because with the exception of changing the inclination of your orbit, burning in any other direction is very inefficient and ineffective. Prograde to speed up/increase altitude of orbit, retrograde to slow down/decrease altitude of orbit. The gimbal in KSP has indicators (green circle for prograde, green circle with an x through it for retrograde)

    4. Depending on the orbital speed of the moon you're shooting for, it's distance from you, and how fast you plan on getting there, you will perform a prograde burn just after passing the opposite side of kerbin. (up to 1/4 past the opposite side, depending on the above factors). This is where it takes experience with your individual craft and your acceleration capabilities to know the most efficient time to fire. Switch to the map view (m) to make sure your orbit is aligned with your target, and to know when to stop firing.

    5. Somewhere around the middle of your journey from Kerbin to your target, you will want to do a correction burn to put you on a much closer course. The lack of gravitational resistance is why we wait until the mid-point. Since there is no atmosphere on the moons, you can shoot for a much lower pe, somewhere around 20k for mun is good, if I remember correctly. At this point you can fire in any direction, not just pg or rg, and will most likely need to do so to optimize your approach. The mechanics for which direction you will need to face in order to adjust your approach are beyond my ability to explain, but a little trial and error (and maybe light reading) will usually suffice. You want as small a pe as possible, but not one that will have you crashing into the planet.

    6. Once you reach pe, fire retrograde only to reduce your velocity and be captured by the target.

    I can write more, but I'm tired and afraid i'm not being very clear. Hope this as least helps you save some fuel getting from a to b.
     
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  11. Turjan Arcane

    Turjan
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    Thanks, this was already very enlightening. Actually, I should have know some of this if I had used my brain, but as you probably know, that's an optional feature.
     
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  12. potatojohn Arcane

    potatojohn
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    To get to the mun,

    1. get into an approximately 100km circular orbit
    2. wait until you see the mun come over the horizon
    3. go into map mode and burn prograde until the mun catches you.
    4. as you get closer to the mun, adjust your trajectory so it goes through the mun. Preferably so it's normal to the surface.
    5. when you get to 60km above the surface, start keeping your speed at about 1/100 of your altitude.
     
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  13. DarkUnderlord Professional Throne Sitter

    DarkUnderlord
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    Ok, I am once again in gravitational pull of the Mun. I have a Mun Periapsis of 780,000m and a Mun Escape in 2 hrs.

    What is the best (most fuel efficient) way to adjust my trajectory so that I get an orbit of the Mun in a way so that I can land?

    I believe I am at this point in the instructions:

    What should I be reading? Should I basically point at the Mun to reduce my pe?

    screenshot0.png screenshot1.png

    This is usually the point where I blow all my fuel trying to land on the fucker.

    Shit cock. I hit the end flight button by mistake instead of saving it and leaving it where I was. Tits. Still, what would be the best thing to do in that circumstance I was in?
     
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  14. potatojohn Arcane

    potatojohn
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    You burn retrograde (opposite the direction you're moving, marked on the navbal) to lower the periapsis to whatever you want. Then you coast to the periapsis and burn retrograde again to circularize the orbit. Then when you're over a good spot to land, you burn retrograde again until you're falling straight down. Then you burn down (retrograde) slowly to land.
     
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  15. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    Assuming you are in elliptical orbit around the moon and just want to slow down for landing, do the burn at apoapsis. That's much more fuel efficient.

    If you want to get into a proper lunar orbit first, it may be more complicated. But orbiting around the Moon doesn't need so much fuel, so you can do it.

    Just make sure that you understand this:

     
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  16. Hamziz Learned

    Hamziz
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    Okay, from looking at your pictures, I see a couple of problems:

    1. You only have one liquid fuel tank left. Ideally, you want about 2 in order to decelerate, land and then take off again and make it back to Kerbin. But that all depends on -
    2. The engine you have looks like one of the more underpowered ones, that doesn't provide a good thrust/fuel consumption ratio.

    The thing with KSP is that because you build your own space craft, yours will have a different weight and power profile than mine. The trick is to experiment with different numbers, types and configurations of stages so that you can get a craft into orbit that is powerful enough to do what you need it to. Unless you're using mods, the torrus (i think that's what it's called) or one of the mid-range liquid rockets usually has enough 'umph' to do the job, but the hard part is getting all that equipment into orbit in the first place.

    Also, be sure you have landing gear equipped that extends below the base of your descent engine, so you don't break it off or blow it up on touchdown. If you're anything like me, you'll want to use it again to take back off. (fun fact: the apollo program lunar lander descent stage stayed on the moon, and only the top half of the lander took back off to rendezvous with the command module in lunar orbit. I haven't been able to do anything similar in KSP, because unless you burn all of the fuel in the descent stage that you plan on leaving behind first, the engine exhaust from the ascent stage causes it to explode, killing everyone.)

    With regard to burning prograde and retrograde only, the exception to that rule is when doing mid-course corrections. Depending on what exactly is 'off' about your approach, short bursts at other directions, either close to prograde or retrograde, or closer to perpendicular to your direction of movement can be very effective, and help save on fuel. You will need to experiment and intuit a bit to figure out where the third axis needs to be - to do this, pick a direction and press 't' to hold your craft there, (i recommend not using rcs thrusters, because the autopilot burns through those way too quickly. instead, leave it on atmospheric control, and it will still do a relatively good job of holding your attitude - a glitch, to be sure, since there is no air in space and this should not technically work, but i digress...) then, add a very small amount of thrust and go to the map view and see how your burn is affecting your orbit. Switch back and forth between the map and main views, changing your orientation each time until you find the direction that seems to be giving you the best results. Then you can increase thrust a bit, comfortable knowing you aren't wasting fuel.

    Let me know if you have any questions, and once you get a good lunar orbit we can focus on actually landing the thing. The idea is to start with a lunar orbit then lower it until it shows you will intercept the planet (although not at too high a speed), then as you get closer to touchdown, you burn retrograde to decrease both your horizontal speed and your rate of descent, slowly 'pitching over' to follow the retrograde indicator, which you want to be in the center of the sky on your gimball when you are 30ish feet from the ground, and at that point have zero horizontal acceleration and zero vertical acceleration (ie, you're not moving at all). Then you decrease thrust to softly touch down. I'm oversimplifying it, but learning to fly by your instruments will help immensely, and you will start to notice that you can 'push' the retrograde indicator across the gimball by firing in a direction a little off from the retrograde indicator, but in a direction 180 degrees opposite from the direction you want it to go. This is how you 'push' the retrograde indicator to the center of the sky on your descent burn, an indication that corresponds with decreasing speed, while at the same time increasing and decreasing thrust to slow your descent. Practice will allow you to perfect the technique. The first time I zeroed out my horizontal speed I was 3,000 feet high, so there's a lot to be said for trial and error.

    As for reading, I believe there are some good tutorials somewhere floating around for both KSP and Orbiter that explain all of the above much better than I can. Da google, I guess.
     
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  17. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    I really recommend you test your lander at the launchpad and practice until controlling the landing becomes second nature, and you get more confidence. Once you did some landings, it's not that hard.

    Your first lander should be simple, consist only of one Advanced SAS Module (will keep the lander upright and still allow control), one tank and the capsule. You can add RCS (ASAS will use it) but it's not necessary. Also, a low construction and more legs with the widest possible base prevent your lander from tipping over (i.e. four is better than three, six is even better). You can also use winglets instead of legs, the construction is sturdier, but also harder to test because they add aerodynamic lift (on the ''Moon this is irrelevant however).

    But really, you should develop the lander first and only afterwards add the main rocket, which is developed seperately. There is only one snag, which is that a lander that behaves ideal on Kerbin is too powerful on the Moon. In the worst case you will be hovering up and down because the engine will not allow the fine adjustments of the throttle that you need, under the lower gravity. Therefore I test with a more powerful engine, but there are some problems, with the size mostly. It's easier to to this with modded parts of course, where you have a larger variety of small engines.
     
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  18. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    An easy way to fly to the moon is to get into orbit and accelerate when the moon rises over the horizon. That way you will hit it every time without fance calculations.

    I have a question myself. Has anyone landed on Duna? I ask because I want to know if the athmosphere is dense enough to allow landing by parachute. A combined parachute / powered descent is of course another option, but it would be better to come down the safest possible way, considering the problems I have to get there in the first place.
     
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  19. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    This is probably not the best solution, but I would have just decelerated (in the opposite direction / the crossed yellow marker) until you are in an elliptical orbit, then wait until you reach apoapsis and decelerate again until your trajectory gets you close to the surface. You still had almost one tank left so imo it would have been more than enough. I presume you still waste too much fuel with course corrections. Also your craft looks quite heavy, try a smaller one (one man capsule) if you have such fuel problems. After a while you realize you don't need a lot fuel for landing on the Moon.
     
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  20. Hamziz Learned

    Hamziz
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    Holy crap, I didn't even realize duna existed....I was so proud when I managed to land on mun and then the other, farther moon, all in one trip and still return safely to kerbin. Now I have a new mission, and my productivity just gave me the finger on the way out the door.
     
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  21. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    Unfortunately they keep removing really nice features. For example persistence: In the previous versions it was possible to switch the camera to floating debris and watch the game from there. Really nice if you have placed something on the Moon or in orbit. Now the debris is cleared automatically before you can really do something. In fact multi part missions as I did in my LP seem to be impossible now. I just found out when I tried to build a special athmospheric mini probes (decoupler + parachutes), to drop from orbit and deploy on other planets.

    Another thing. The game has always been a bit heavy in superfluous submenus, but they keep adding new ones. Thanks to the "amazing" speed and responiveness of the Unity Engine, even the simple act of clicking though the start of a new game becomes an absolute chore. Start New Game - click - lag for 2-3 seconds - Continue Saved Game - click - lag for 2-3 seconds - select game from much too small window - click - lag for 2-3 seconds - Click on vehicle Assembly - lag for 2-3 seconds - loaf ship blah blah blah etc. Go to launchpad - five seconds lag before the game starts responding. Or just pay attention to how long it takes to even exit the frigging game, compared to a "normal" program written without Unity.

    The new version adds some nice features, but Unity sucks. We can only hope it's C#, that WL2 and games are possibly written in C++ and more responsive, otherwise the new age of gaming will be a chore because of the fucking engine.
     
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  22. potatojohn Arcane

    potatojohn
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    Huh? Mine doesn't clear debris. I still have stuff up there that's been orbiting for years. In fact lately I've begun dropping stages so they crash into planets to avoid littering the space too much.
     
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  23. potatojohn Arcane

    potatojohn
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    Some screenshots

    This is my rocket. There are many like it, but this one is mine. My rocket is my best friend. It is my life. I must master it as I must master my life.
    [​IMG]

    The Jool orbiter went hyperbolic while I was waiting for a launch window. Either a bug or orbital interactions with the moons threw it out.
    [​IMG]

    Asshole moon decides to get in the way
    [​IMG]

    Parachutes work great on Duna
    [​IMG]
     
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  24. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    I built a mini probe (consisting of a parachute, a decoupler and some other part like a nose cone), and I had planned to follow it on it's descent to Eve (in fact I planned to drop several of the things) while my capsule stayed in orbit.

    What I did was I test dropped the stuff from ca 8000, the parachute opened, but it dissapeared quickly, and I could not switch the camera to the objects.

    Perhaps I was too hasty & it's different if I drop it from orbit, but so far it looks like the experiment from my 0.15 LP cannot be replicated. I had dropped several dummy astronauts on the Moon and followed them until impact (near the bottom in the Kernd Rosemeyer Mission).

    Now I thought with an athmosphere and parachutes this could be used for nice multiprobe missions.

    [​IMG]

    [​IMG]

    Another explanation would be that the parachutes did open but do not slow down the objects because there is only partial physics on the debris?
     
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  25. Burning Bridges Enviado de meu SM-G3502T usando Tapatalk

    Burning Bridges
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    Gawd, I can't figure out how to rendezvous with a planet.

    I just ran the sim in 100K time compression, hoping Duna or Eve would catch me but even if they come really close - even after years - nothing ever happened. Compared to that the flight to the Moon is an absolute piece of cake.

    I'll try one more time with the correct planetary phase and ejection angles, then I give up.
     
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