Ivan Ivanovich

I\'ll try to answer what I can answer. SLINGSHOTS Your orbit looks a bit like it is not quite 'in sync' with the Munar orbit. I.e. tilted towards it. Of course the Mun will only 'catch' you if you are close enough, just being as far away as the Mun, even if your viewing angle looks like you\'re right 'on' it won\'t suffice. Are you perfectly sure that you were REALLY close to the Mun, not just on the same side of Kerbin? LIFTOFF There is actually a chart (it was posted here), where atmospheric drag outweighs impulse gain from max thrust. As a rule of thumb, this seems to be the case at a TWR (thrust-weight ratio) of roughly 2:1. So far, I didn\'t manage to build a Mun-capable rocket with a TWR coming even CLOSE to 2:1 (mine usually have a TWR of about 1.2:1 to 1.4:1). So I guess as long as your rockets are 'too heavy' to be near 2:1, full throttle it is. ORBITAL INSERTION There is no absolute answer to this, it depends on too many variables. It IS in general more efficient to keep the engines on and on full throttle (at least as soon as atmospheric drag is no issue anymore) due to the law of conservation of momentum, but that may not be in your interest since it might burn fuel to get where you don\'t want to go (e.g. it would lead to a high Apogee opposite of your intended flight direction). My usual approach is to cut the engines when my apogee is high enough to stay out of the atmosphere even after I leave it (as long as you\'re in the atmosphere, your apogee will fall due to drag loss) AND I\'m certain I will have enough thrust to keep the AP ahead of me when I turn them back on. Hence I tend to bank rather early in the flight and get to a mostly horizontal thrust well before leaving the atmosphere (usually I have about 2200 m/s when my engines get turned off, most of it horizontal movement). ORBITING It is modeled that way and yes, you need less fuel orbiting towards 90°. HOHMANN TRANS MUNAR INJECTION The 'fact' that you burn at rising/setting Mun is due to how fast the Mun revolves around Kerbin and how far away it is from Kerbin. I\'d guess the game was built that way to make the trip there easier. Personally, I burn based on the overview map, because then it is (mostly) independent of my actual altitude when initiating the TMI. I burn when I fit the Mun in the fully tilted orbital map right into the upper right corner of my screen (at the correct zoom), with Kerbin as the target and my craft right 'below' Kerbin on the overview map. That puts me a bit ahead of Kerbin, despite aiming for an Apogee that\'s a bit short of the Mun orbit. I guess it\'s about the least fuel consuming option I have. The reason for this is simple: Your Apogee will be opposite to where you initiate the TMI. Since your previous Ap/Pe pair was insignificant compared to the target Apogee (about 70km vs. 11.000), you WILL be at Perigee when you shut the engines off. In other words, you will fly towards wherever your opposite end of the orbit is pointing. Add that the trip to the Mun takes approximately 1/6 to 1/4 of a Munar orbit around Kerbin and you know why you burn at Munrise/Munset. MUNAR LANDING Personally, I get into a Munar orbit first. It\'s not necessarily a stable orbit, more a result of the way I get there. First I install a Perigee of about 5-10km, then at that perigee I bring down the Apogee (which then turns into the Perigee, of course) to the ground a bit behind my intended target area. That usually gets me in position for landing at about 2000 meters. There I do a burn to kill lateral speed, put my rocket upright, zero the lateral speed with RCS and then, well, land. Personally I think there is no easier way. LEAVING THE MUN Easy as pie. Start, bank towards 90° and get into an orbit. Altitude doesn\'t really matter, just keep it low to conserve fuel. Keep an eye on the overview map, it\'s VERY easy on the Mun to suddenly end up with an Apogee of 20+ km and you don\'t know where it came from. Just put enough thrust into it to get an Apogee that\'s a bit ahead of you, switch to the overview map and keep that AP ahead of you a few meters until you have a more or less stable orbit. Then wait until you reach the 'orbit line' of the Mun around Kerbin on the 'front' of the Mun (i.e. the side the Mun is going to. It\'s where your flight indicator points towards Kerbin. There, throttle up to about 900m/s. Yes, that results in an escape trajectory from the Mun that points to the 'left' of Kerbin. No problem there. You see, as we move, and Kerbin does, it will catch us. You will end up in a very elliptical orbit, but that\'s no biggie. Now, depending on how much fuel you have left, either lower your Apogee a little to enable a smooth landing or, if you\'re low on fuel, wait until you\'re at Apogee and lower the Perigee down to Kerbin\'s ground (or at least about 30km above, give or take depending on your Apogee, the higher the Apogee, the lower you\'d have to get the Perigee unless you don\'t mind taking another round around the marble). Note that in 'reality' you would want to get a low Apogee to ensure a smooth reentry. The higher your Apogee, the faster your reentry speed, resulting in very high g-force and (as soon as it is implemented) the risk of burning up in the atmosphere. But for now that\'s not really an issue. And yes, it\'s very possible to do a reentry with 2.5g and less.

If I\'m not mistaken your table calls for a TWR of about 2, maybe a bit lower at the start (provided some dead weight can be jettisoned during ascent). A TWR of 2 (or close to it) is pretty hard to achieve with a Mun-capable rocket. My Mun rocket has an initial TWR of 1.2:1, actually. My Mun return craft weighs 7.6 ton, which is dead weight during ascent. Given that I have 6 + 1 engines thrusting initially, giving me 1375 thrust, for a TWR of 2:1 my ascent stage may only weigh about 61 ton, which is basically 14 tons for the engines and 18 fuel tanks. That\'s not enough for a Mun shot.

I would not recommend doing such a thing, it would require you to spend a prolonged time in the denser atmosphere. Instead I would suggest getting to a sensible height, pushing the apogee to where you want it to be, shut off engines and reignite them when you\'re at apogee to push perigee up to it.

http://kerbalspaceprogram.com/forum/index.php?topic=4137.0 It is a bit outdated by now, but it should still give you an idea.

Umm... maybe I get you wrong, but how about keeping RCS off while ASAS is on?

Included my current Mun craft, the MunCraft XI. Yeah, it is actually already my 11th design. Admittedly a fairly conventional design, consisting of two main stages where the first stage, the one that takes you to the Mun, is further divided in three stages. As you move towards the Mun, you keep tossing away the outer legs, three already during the primary ascent, the next three usually during the TMI, which leads to very few debris littering your orbit, the first three legs crash down onto Kerbin, the latter three normally disappear into deep space or get into a highly elliptical orbit that doesn\'t bother you too much during your next missions. The final part, the center piece, has enough power and fuel for Mun orbital maneuvering and putting you into a landing position before you toss it down onto the Mun just before landing. The landing stage is also the return stage, and with 3 half size fuel tanks it has more than plenty of fuel to get you home. The single RCS tank is enough to make landings on the Mun very easy and is mostly used to zero lateral movement during Mun descent and the ASAS is quite capable of keeping the rocket stable during all phases of the flight. Try it out, it\'s easy to use.

Mun? MUN? We would have killed for a Mun! We had nothing. Nothing! We pretty much had to carry those rockets all the way to orbit ourselves. And THIS high was the snow! And we didn\'t have any fancy moon boots, nossir! There was no overview map. No hitting M and suddenly all magically you get to see where your Apogee and Perigee will be, we had to whip out our trusty calculators and go to town on orbital mechanics! You wanted to know whether your Perigee is high enough to stay above the atmosphere? Well, you better know what speed you need at the height you\'re at! No time warp. No such thing, we had to wait for half an hour or longer for our ship to make an orbit. You wanted to land near the space port? Well, better get a good book with you, because you\'re in for at least 22 minutes of waiting. And then you better know that planet from space and know when the port is about to appear! No RCS. No fancy shifting sideways, you wanted to fake dock? Well, turn that rocket \'round, sonny, the only kind of thrust you have is coming from your main engine! No ASAS. Today, switch on ASAS and it takes you to orbit. Not for us, we only had the piddly crap SAS is, and we were GLAD we had it! No fancy rocket options, we only had one main tank, one main engine and boosters. Yeah, that\'s it. No gimballed engine, no half-sized fuel tanks, no cute little engine for smaller thrust, we had to be able to push our rocket very, very carefully. Because it sure knew how to overheat and blow up! No saving feature. You wanted to see your rocket land, you had to sit it out, with no time warping! You don\'t even know how good you got it. And now get offa my lawn!

Raising/lowering Apogee/Perigee To lower Apogee: Burn against the flight direction at Perigee. To raise Apogee: Burn towards the flight direction at Perigee. To lower Perigee: Burn against the flight direction at Apogee. To raise Perigee: Burn towards the flight direction at Apogee. Moving Apogee/Perigee along flight path To move Perigee against flight direction: Burn towards flight direction when you are past Perigee OR burn against flight direction when you are before Perigee. To move Apogee against flight direction: Burn towards flight direction when you are past Apogee OR burn against flight direction when you are before Apogee. To move Perigee towards flight direction: Burn against flight direction when you are past Perigee OR burn towards flight direction when you are before Perigee. To move Apogee towards flight direction: Burn against flight direction when you are past Apogee OR burn towards flight direction when you are before Apogee. Note: This will also change your Apogee/Perigee, depending on where you execute the maneuver. The closer you are to either position, the more the other one will change. Tilting flight axis At Apogee/Perigee, burn towards the direction you plan to shift your plane to, normal to the flight plane. Note: As the plane shifts, the direction you burn towards has to change as well.

Ah yes, forgot decouplers. That works too, but I\'m a fan of RCS tanks. They really help a lot when landing on the Mun

Thanks for all the replies, I will try to keep the rockets updated. Though I\'m not entirely sure whether I should update to the 'pay' version or whether new rocket enthusiasts would probably benefit more from a version that uses the free version, considering that most people will probably try before buying... decisions, decision. In the meantime, fuel lines. ... I guess I\'ll start a new topic about that, here it\'s probably going to be lost too easily in the static. You can find it here: http://kerbalspaceprogram.com/forum/index.php?topic=8368.0

Fuel lines are often misunderstood and even more often used wrongly. And I guess I, too, didn\'t quite get them fully yet. But this guide should give you a first clue about the dos and don\'ts of fuel lines. How and where to attach them - the basics Fuel lines are the yellow thingamajigs in the third ledger, first item (always assuming you didn\'t install any add ons). Fuel lines work a bit like struts, i.e. they have two connection points which have to be 'visible' for each other, unobstructed by any other part of your rocket. If there is something in between them, the connection will end at the blocking item. Unlike struts, fuel lines have a direction. The tiny arrows on it indicate the direction the fuel will flow. Note that the fuel will ONLY flow in this direction. You decide which way the fuel goes by the order in which you attach them. The first tank you attach them to will be the tank FROM which you want the fuel to flow. The second point (where you attach the rubberbanding fuel line) will be the receiving end. Note also that fuel lines can ONLY flow from fuel tank to fuel tank. You can NOT attach a fuel line to an engine, to a SAS module or to the capsule. Well, you can attach them, but they\'re useless there. As a rule of thumb, make certain that your fuel lines are connected to a tank. RCS tanks DO work as targets, but afaik they\'re not good as sources. If they are target of a fuel line, whatever is below them will receive the fuel. This is the only way I know of how you can power an engine without an engine fuel tank on top of it. Whether your fuel line 'works' can be seen when the rocket is flying on the staging list to the left. If the fuel line is lit (in blue, like a powered engine or a not-empty fuel tank), it 'works' (i.e. fuel is running through it). If it is gray, it\'s dry and no fuel is flowing through it. This can of course be the case when the 'from' tank has been drained (then it should be gray), but if fuel should flow but it\'s gray, something is wrong and you should reconsider your setup. First test Build this rocket: Capsule (with parachute, if you insist in your Kerbonauts to survive) stack decoupler (ASAS if you\'re lazy) 1 fuel tank Engine 3 radial decouplers around the fuel tank 2 fuel tanks on every radial decoupler 1 engine under every radially attached fuel tank 1 fuel line FROM the lower radially attached tanks TO the tank in the middle. Rearrange the stages so all engines fire simultanously (but keep the inside tank separate from the outside tanks so you can see what\'s happening) and launch the rocket. You will notice that four engines are firing, but only three tanks are being drained. The reason for this is that the radially attached tanks also fuel the central engine since the fuel lines funnel fuel from the tanks outside to the engine inside. All the six outside tanks will be drained eventually and the three outside engines shut down while the inside tank is still completely full and the inside engine has a full tank to draw from. Fuel lines are like real estate. What matters is location, location, location Let\'s alter the setup a bit. Now, move the fuel line to link FROM the UPPER radially attached tanks to the tank in the middle and launch again. At first, it will look like the first attempt. Three tanks will get drained, four engines are firing. But as soon as the first outside tank is empty, an important difference gets visible: Now all remaining tanks are being drained. How the magic works Think of it as a matter of gravity. As long as there are full fuel tanks 'above' the place where the FROM fuel line link is placed, fuel will flow. As far as I can judge, it does not matter whether you place the fuel link on the bottom or the top of a single tank, what matters is the tank\'s position in the stack. How to profit from it There are two things that you can benefit from this: First, to drain throwaway tanks quickly and carry as little dead weight as possible, and second, to level out fuel consumption over your engines. Sucking few tanks dry to leave the rest full The first idea is to slap a few 'booster' liquid stages radially to the rocket, pump the fuel from them to the inside and throw them away as soon as they\'re dry, sacrificing an engine but keeping all the remaining engines and tanks full. To do this, attach a fuel line from the bottom outside tanks to the inside tanks. You can stack them radially, i.e. if you have three 'layers' of tanks radially attached, you can pump from the outside tanks to the middle tanks and from there to the inside tanks and fuel ALL engines from the outside tanks. What will happen now is that the tanks will drain VERY fast since they have to supply quite a few engines (I once built a setup where 12 engines sucked from a single tank, it was dry in 5 seconds), but you can easily gain a lot of height that way, dump the outside attached fuel legs and still have a fully fueled rocket at your hands with zero dead weight. Evening out the consumption The other idea comes into play when you 'suffer' from engines that drain their fuel at different speeds (like the gimballed engine and the more powerful but less controllable one) but want them all to run the whole length. If you simply place, e.g. 4 tanks on top of a gimballed engine and 4 tanks around it on normal engines, the normal ones will have run dry by the time you still have 1/2 fuel tank left for the gimballed one. Now, you could of course just toss the powerful ones and putter about with the thrust from the gimballed engine, but if you\'re not in orbit yet, this might not be an option and you\'d have to toss the half full tank and stage to your next full complement of engines. Here, the idea is to even out the fuel consumption over the engines. Now, the gimballed engine consumes 7/8th the fuel of the powerhorses, which means that you COULD in theory put 7 fuel tanks on the gimbal engine and 8 on the powerful ones, but since that couldn\'t even remotely take off, it\'s no option. The easiest way to even this out is to combine it with the first idea. Build this (as the power stage): 3 fuel tanks on top of a gimballed engine. 6 radially attached fuel stacks, 3x3 and 3x4 fuel tanks tall, each with a powerful engine below. A fuel line from each of the topmost tank of the 4 fuel tanks tall legs to the 3-fuel tall ones. I.e. 3 fuel lines running from each ot the 'tall' stacks to one of the 'short' stacks besdides it. That means that the topmost of the 4-fuel tall stacks gets drained by two engines, from there downwards, every stack gets drained by its own engine. That way, each 'powerful' engine has 3.5 fuel tanks to draw from while the gimballed engine draws from 3 tanks, resulting in a simultanous (ok, not quite but almost) shutdown. Now, what does and what does not work The obvious idea of drawing fuel from the upper stages to 'even out' fuel consumption or 'top off' the fuel hungry powerful engines doesn\'t work for a simple reason: Tanks are drained top to bottom. I.e. you\'d end up draining your upper stages before the lower stages are even being touched. I haven\'t found a way to get around this, sorry. If it\'s possible, feel invited to post it. You also cannot use fuel lines directly to engines or SAS modules. So a lander consisting of ASAS with an engine below and two tanks attached left and right does NOT work. You CAN attach fuel lines to RCS fuel tanks, though. Hence, my Mun lander consisting of parachute capsule decoupler ASAS RCS engine 2 tanks attached left and right 2 fuel lines from tanks to RCS tank DOES work. Fuel DOES pass through a stack decoupler, so upgrading the above setup by adding a decoupler between RCS tank and engine DOES work. But it gets quite heavy. That also means that you can jettison spent tanks 'above' the ones you\'re using. I.e. if you radially attach a tank stack at the bottommost tank and stack tanks above it, you can, e.g. insert a stack decoupler every 2-3 tanks and toss them. It is definitely NOT recommended, though, for ascent stages where you can\'t simply shut off your engine for a while to toss them, navigate past them at leisure and continue your flight. Consider: They are tossed ahead of you. Now guess where you\'re going in powered flight... I would recommend getting a decoupler with negative ejection force for something like that, though. Just a warning...

Wait... what? HOW? Is Docking in place and nobody bothered to call me? Grumble...

And again new crafts to reflect the 0.13.1 changes to fuel lines.

Umm... do I have to return with a standard reentry or can I make a powered return? The latter should be rather trivial.

In general, it doesn\'t matter what stage the struts are in (hmm... it might maybe be an idea to make them hideable so they don\'t clutter the staging list... maybe a suggestion to make...), they are 'always on', just like fins or fuel lines, and they will detach automatically when the couplers that hold the stage they secure blow.

In more detail, you need at least one RCS fuel tank and a few RCS thrusters attached somewhere on your craft. They need not be attached to the tank. To activate the RCS thrusters, press R. Now they will support the attitude changes you execute with wasd, their main reason to exist is, though, their ability to move 'sideways' with them and forwards/backwards with ijkl and h (forwards) and n backwards). They are also controlled by your ASAS module, so they are usually quite useful during Mun landings. Just turn on ASAS and RCS and have your ASAS balance your craft.

Welcome back, hope your vacation was better than mine. And you know that you now started the rumor mill, yes? I hope you\'re happy, now I can\'t sleep, wondering just what .14 is gonna get us.

Time and again, my experience, adding people to a late project makes it later. But seriously now. \'tis wonderful to see people being added to the project, gives me the feeling they want this to succeed and see it as something that will. Since there\'s not any release moment pressing down their necks, adding people to a project usually means that they see it as something that will be a success and either generate a ton of money or that allows them to mark their territory in the game market. Either way, I\'d take it as a good sign.

It seems that the fuel lines got turned around, i.e. instead of the connection direction '1 click \'to\', second click \'from\'' it\'s now reverse. Since it seems that also works for the existing designs, rest assured I had my moment of Kerbalism when I took off and jettisoned my \'spent\' tanks, only to watch the spent tanks and the engines attached to them pass me upwards since THEY were the tanks with the fuel. Not the dry ones I had left on my rocket.

Actually, the engines need at least one 'fuel transporting' part on top of them. This can be pretty much anything from the stock setup but ASAS modules. My standard lander config consists of parachute capsule decoupler RCS tank engine 2 tanks attached left and right to the RCS tank and a fuel line from RCS to fuel tanks. Gives you a fairly 'short' lander, making it quite stable. I tried 3 fuel tanks around the center module but that made it kinda heavy, and you only need two to get back with plenty of fuel to spare.

ASAS doesn\'t have more effect, actually, it has a different effect. ASAS steers your craft actively and is, essentially, nothing more than an autopilot trying to use the controls to keep you on course. SAS on the other hand is a passive module much like a gyroscope that keeps you on course by virtue of inertia. ASAS is superior in most situations, at least as long as steering can actually compensate the unwanted movement of your rocket. As soon as you\'re constantly steering at the maximum and still cannot compensate, a SAS module (or a few of them) might help.

What exactly seems to be the problem?

So lemme get this straight, just peppering the Mun sky with sats (or stations, which I\'d prefer) is going to be enough? No need to, say, put them into different orbits? Gimme a sec...

A few questions to clarify: 1. Do we have to achieve an orbit first, or do you want a simple 'hop to the pole'? 2. Do we have to shed everything but the lander before getting there (i.e. shed everything but capsule and parachute, for a 'standard' reentry landing)? If not, it should be trivial to float and slide about until we get to the right spot...

Did you get to orbit on two tanks or just beyond the atmosphere?