DMagic

Not each way. Coming back from the Mun does not take another 860 m/s. It should take only a little more than what's necessary to break Mun orbit. I don't know the value off the top of my head for the Mun, but from Minmus it only takes about 150-175 m/s to get from a 25km orbit back to Kerbin. If you're just getting back to Mun orbit, like the OP, that doesn't matter, but if you're planning to return to Kerbin you shouldn't need that much delta-v.

It could be. Does this happen right away? or during the later stages of ascent. If you have a lot of fuel at the top you can sometimes manually transfer it down to your lower stages to make it less top heavy. This can be a little tricky though, and that fuel is usually there for a reason. This could also mean there is an imbalance somewhere that is pulling the rocket off center. Being too wobbly can also make things tip over sometimes, too.

You're not quite doing it right. The 2 pink icons do not indicate the target's velocity vectors, they indicate the actual, current, position of the target. Pointing at the pink circle means you are pointed directly at the target. You need to switch the navball to target mode, click on the the little window above the navball until it says target. This is how you can see the target's relative velocity. If you point at the yellow x in target mode you can then reduce your relative velocity to 0. Then you can use the pink icons to move toward the target.

I think it would be really hard to go directly to a Laythe capture, I've had chance encounters with Laythe after enter Jool's SOI, but planning that ahead would be tough. And really it takes almost nothing to aerobrake at Jool first and then wait for a Laythe encounter (assuming you get a good orbit on the first attempt). All it takes to prevent another dip into Jool's atmosphere is maybe 5 or 10 m/s. And, at least for me, it never takes long to get an encounter with Laythe after that, usually 3 or 4 orbits at most. Depending on how close your subsequent Laythe encounter is, you may need another 100 or 200 m/s to get into it's atmosphere, but that's not too bad. That said, planning ahead to get a Laythe encounter before getting to Jool would be really awesome.

Now that I'm on my way to Jool we can take a closer look at the different components of my spacecraft. Here is the core module and one of the light Pol/Bop landers. You can see that the core is very simple, just a fuel tank and a big engine (that's the nuclear engine from the Kosmos pack, I used it just because I like the way it looks, it is no more powerful than the regular engine and it weighs a lot more). The trusses are actually very stable when accelerating, with just a little bit of flexing at the docking ports for the heavier landers. The big RCS thruster on top helps with turning and stabilizing the craft. On the right is the light lander, which is actually made up of four separate crafts. On the bottom is an extra fuel tank used to refuel the core stage after the transfer burn to Jool. This will be released with a few L of fuel and set to plunge into Jool, one on as steep a descent as possible, and the other on a bit of a slower path. On top there are two small probes that will be released upon achieving orbit around Pol/Bop. One is a small Sat Map probe with enough fuel to set up a wide, polar orbit. The other is a small lander that will be used to scout out possible sites for the manned lander. In the center we have the lander itself, with fuel enough to line up my orbit with the target, land, take off again, and meet with the carrier back in Laythe orbit, this time a lot lighter, with many fewer parts. Here we have the mid sized Vall lander, and the heavy Tylo lander. The Vall craft has the same two probes on top, the lander has a bit more fuel to compensate for Vall's much higher mass. The landing struts on the radial tanks give the small lander plenty of clearance, so it will be deployed after landing with the radial engines. The lander can then blast off again and meet up with the carrier. The Tylo lander doesn't have any Sat Map or lander probes, since I already launched those, but it does have a small Jool relay probe on top. This will be released during the transit to Jool and should arrive several days ahead of the other craft to act as a communications relay in high Jool orbit. It carries another rover on the bottom which will be released upon landing. The tall, radial fuel tank stacks will only be used for the descent stage, dropping off before the final landing. The radial engines are only there to give the final boost necessary for landing, and the first stage of take off. The central, nuclear engine should be able to finish getting the craft into orbit and to get back to the carrier around Laythe. Neither of these two ships have RCS thrusters on the final stages, so docking should be tricky, but doable. I found that a stack of I-beams work great when you need to have a really long ladder. The first Jool probes and the communications relay are released after setting up a reasonably close encounter with Jool. They are each set to arrive about a day apart from each other, and about 5 days ahead of the main craft. Just after reaching the Jool system I released the Bop and Pol landers. This far out they can perform most of the inclination change necessary to reach their targets without spending much fuel. This lets me keep the main craft on an almost flat inclination for the initial approach to Jool. This is what I call orbital spaghetti. The two probes are set to crash into Jool, while the relay probe arcs behind the planet in a highly inclined path. The two landers are at an inclination that will let them meet up with Pol and Bop, the orbits of which can be seen along the top. One of the landers looks like it will have a glancing encounter with Laythe, but it doesn't seem like it will have much of an effect. The three main craft are all set to aerobrake around 30 minutes apart, so I'll have to be careful about the timing. The two probes meet their inevitable demise, quickly at first, and then slowly, as they drift down in the increasingly dense atmosphere of Jool. The probe on the direct descent peaked at over 190 g's, while the probe on the more gradual path 'only' reached around 80 g's, valuable information for someone, I'm sure. The relay had a harrowing trip through the upper atmosphere but made it through alright. Laythe, Tylo, Vall, Pol, and Kerbol were all aligned during this stage, though you can only really see Laythe here. Up next I'll set up my initial encounters with the moons, map out the targets to determine suitable landing sites, and begin exploring.

I think the 7km/s to Laythe was from LKO, not the surface. But still, that is way more than you need. If you get your timing right for the burn from LKO to Jool it should take no more than 2km/s, and then another 500 m/s or so for orbital corrections, and lining up aerobraking right.

That depends on what you mean by slingshot. If you are talking about a passive gravity assist, where you simply fly close to the planet, then no; how far away your starting point is doesn't matter. If you are talking about a powered maneuver, where you wait until you are as close as possible to the planet (and going as fast as possible), then igniting your engines, then yes, you can; this is what people are talking about when they refer to the Oberth effect. Flying out to Minmus first won't help by itself, but if you do what you are planning, refueling in Minmus orbit, then it can definitely be useful. You will lose about 150 m/s getting out of Minmus orbit, but after that it will only take another 100-200 m/s to get to Duna.

It's not that the delta-v has a greater effect, it's that it takes less time to achieve that delta-v. Your engines produce a constant force for as long as you burn them (assuming you are at full throttle the whole time), the faster you are traveling, the more energy this imparts on spacecraft in a given amount of time. The energy imparted by your engines is calculated by W=Force x Distance. Force is constant from your engines, and it takes less time to travel a certain distance if you are already going faster. There is, of course, a Scott Manley video on breaking Kerbin orbit from Minmus directly, vs returning to a low Kerbin orbit first before burning. It definitely saves fuel to do it this way, but it's trickier to pull off as others have said. But I was talking about the gravity slingshot, or 'assist'. That doesn't have any effect here. Although, you might be able to first return from Minmus, then pass close behind the Mun on the way out and save a small amount of delta-v that way, and use that to alter your direction for a more optimal transfer to Duna. That would be hard though, and really awesome.

You do have a very high orbital velocity at your periapsis when you return from a moon, but you could achieve the same effect by making a 2-step orbital transfer. Burn once from LKO to a highly elliptical orbit, then the second time around burn until you hit escape velocity and set up a Duna encounter. The difference is that this 2-step burn doesn't include the delta-v necessary to enter and leave orbit around the Mun/Minmus. That said, I do have an orbital fuel station around Minmus, and I think it's cool to do more complicated maneuvers like this, just not necessarily better. And the 'gravity boost' from Kerbin doesn't have any effect here. Just think about it, if a highly elliptical orbit somehow gave you a boost in your orbital velocity then every time you went around Kerbin your orbit would get a little higher. There are other threads that go into this more, but it's not as simple as it is sometimes suggested to be.

Actually, I think more like 2 m/hour is more realistic, at least for unmanned rovers. The Mars rovers crawl along, stopping to check and make adjustments constantly. Opportunity has been on Mars for over 9 years and has only moved about 35km, which is about 10 meters per day. That said, if you want to keep from tipping over or veering off course make sure to do everything in docking mode, that way you aren't pitching to the sides when you accelerate or turn. And for low gravity situations, like Minmus, you just have to accelerate slowly, just tap 'w' until your speed gets up. And be careful slowing down and turning, too, if you don't have a wide wheel base it can really be easy to tip over if you're not careful.

After setting up a base and communications relay around Laythe I decided to conduct a manned survey of the other Jool moons. I'm planning on making a single carrier ship to ferry landers for the 4 other moons. Landers for Pol, Bop, and Vall were designed based on, um, ground-based observations of the Jool moons, but I decided I needed to take a closer look at Tylo and its massive gravity well before finalizing my lander for that moon. I'll try to stitch together some of my images to avoid putting up unnecessarily long posts. Here is my Laythe base, Quad-Mega Base 2.0, which will be conducting operations on the Jool side of things. This is the launcher and a shot of the probes sent to Tylo. The less said about the ill-fated lander the better, but the orbital Sat-Map probe, visible underneath the lander, worked fine. I was able to map everything up to about 70 degrees north/south of the equator. My next lander design worked out much better. As expected mechjeb failed miserably at landing, running out of fuel about 500m above the surface. But I was able to bring it down myself with plenty to spare. I landed at a fairly high region, about 8km up, using about 3000m/s of delta-v. With this information in hand I finalized my Tylo lander design and finished launching the components of my mission. From left to right, we have the core vehicle, Endurance, the identical Bop/Pol landers, the mid-sized Vall vehicle, and the heavy lander for Tylo. Rendezvous and orbital refueling took place at my Minmus orbital fuel station. Most of the mod parts come from the Kosmos pack, with a few fuel tanks from KW, radial engines and command pods from HOME, and a few Sat-Map probes. The assembled vehicle is about 225 tons, made up of 364 parts, with a crew of 11 Kerbals, and a total of 16 different crafts, including the core carrier, and the landers, rovers and probes. This picture clearly shows that I'm a no-talent hack, who just threw together some parts and clicked the 'fly-mission' button. Or, no, I mean it shows my exit from Minmus, and shows the flaw that should be obvious from the previous picture, that my vessel is severely unbalanced. The heavy Tylo lander is about 75 tons, while the Vall lander is only 45 tons, meaning the whole thing will pull towards the heavier side. With a full fuel load and no way to balance things out or set engines at different throttle levels, I have to use the Vall booster engine to adjust my heading. Activating and deactivating it allows me to, more or less, stay on course, but it's pretty tedious. Once I got back down to lower Kerbin orbit I activated the radial engines to take as much advantage of my high velocity as possible. I still had to play around with balancing thrust levels, but it wasn't quite so bad at this point. After a few minutes of this I deactivated all but the 3 nuclear engines and carried out the rest of the burn, and I was able to finally balance the load enough to stay on target and successfully set up a Jool encounter. Another crucially important bit of information that I learned, which in retrospect should have been head-slappingly obvious, during these burns, was that the amount of delta-v required to move from a moon, back to a low orbit of the the planet is only slightly more than what's necessary to break orbit around the moon. I had been thinking that returning from a moon to a low orbit around the planet would take a delta-v equal to that required to get to the moon in the first place. Which is of course, dumb; that's what it would take to get back to low orbit, and then circularize my orbit at that point. So all of my landers were designed with 1000-1500 m/s of extra delta-v that I was planning on using to get from the outer moons down to a Laythe orbit. So this should simplify some things, allowing me to set up encounters of Bop and Pol, the two small, highly inclined, moons without dragging the whole vehicle along for the ride, and maybe ensure that I actually have enough fuel for the return trip. It's amazing how many things there are to learn after 200 hours of playing. Next up I have to optimize my Jool encounter, launch some of the initial probes, and figure out the ideal way to launch and set up encounters for the Bop and Pol landers.

This is a good idea, small probes are really easy to get into orbit and fly to the Mun with. This lets you focus on learning how to do orbital insertions and land without having to spend so much time worrying about having enough fuel or how to make complex, multi-stage, descent and ascent vehicles. And docking is definitely one of the more difficult aspects of the game; there are different issues to consider with almost every different craft you make. Getting the RCS thrusters properly placed around, or at, the center of mass helps more than anything, I think. But it can be tough to figure out when you only have a partial fuel load, or you are moving several components around. My only other advice is to do everything with CAPS lock on, and always work in the chase view so that your movements are always consistant and predictable.

I docked two components together on the surface of Minmus only to watch the whole thing do a slow motion somersault. But somehow nothing was damaged and I was able to hit time warp as soon as it landed back upright. I did this with another identical component, but nothing happened. That's the only time this kind of docking weirdness has happened to me.

Yep, at least they look like they are. I think you have to retract and extend them again to get everything working again after reloading. And even better, those upper panels tend to crumble after a reload. The first time I loaded this base 4 of the 6 central panels fell apart. As a precaution I just retract everything before I leave anything with the Kosmos solar panels. The HOME modules do the same thing sometimes, too. I do like the Kosmos pack for base and station structural components though. They look better than the default parts, and they offer a lot of variability to how you can connect all your components.

It really does, and planning a successful land-and-return trip is even harder. In some ways I think Minmus is an easier target. It takes a little bit more to get there, but it's so easy to get into orbit, land, and take off again. But I rarely see anyone trying to achieve that before going to the Mun. It seems so much further away, that might be part of it, and that inclination can be tricky, but it really is a lot easier in my mind.

Assuming that there is air inside the rocket then he's not really disconnected from it.

Actually, this thread, a little down the list has a really great chart for this. http://forum.kerbalspaceprogram.com/showthread.php/26393-Handy-interesting-graphs-charts

http://wiki.kerbalspaceprogram.com/wiki/Kerbin This doesn't take into account how much delta-v is required to get into orbit, just how much it takes to get to the planet. But Jool has an atmosphere so it shouldn't really require anything beyond a little for orbital adjustments. 8.4 km/s is enough to get you there and back twice at least.

I don't think that's how multi-core processors work. They are constantly balancing the load across all of the cores, there are probably lots of reason for this, but one of them is even heat dissipation.

The default maneuver node editor is really tough to use for fine tuning transfer orbits like this. It tends to close and be hard to reopen, it hard to make very small changes (sometimes 0.05 m/s changes make a big difference when you are so far away), and, like you mentioned, when you have closely overlapping orbits you have to be careful to set the node for your current orbit, not the next one. But in general I just try to get an encounter with the initial burn. Usually I am a little above or below the planets orbit, so there is an ascending or descending node somewhere along the way. That's a good place to do your correction burn (if it's not too close to the target planet). Sometimes just a tiny adjustment in your inclination can get you much closer to the planet. Sometimes when I get tired of dealing with nodes I just do little random burns to get as close as I can. Just point in a random direction, throttle up to maybe 3-5% and see whether your periapsis around the target planet increases or decreases, it usually increases. I generally only do this with RCS, or ion engines, but if you are careful and persistant you can get really close.

A lot of the time I just start putting something together in the VAB. Sometimes I'll go back and redesign something even if I can already get it into orbit, just to make it smaller, or to make a few changes. But sometimes I go all out in planning. This was the first step into putting together what I showed in the base thread. The final version actually turned out pretty close, except for 1 component that I added because I didn't quite understand how Kethane refining worked. The numbers written everywhere are part counts and estimates as I refined things.

I finally finished all the parts of my MinMus base and orbital refueling station. Here is the orbital station, it's all stock parts. I put it together with just 2 launches of identical parts. There are 10 orange fuel tanks for 28000 fuel, and 8 large RCS tanks for 6000 units of monopropellant. I wasn't stingy at all with parts, there are a ton of aesthetic touches, like the fuel lines, and the docking ports (6 large and 4 small) could have easily been stuck directly on the fuel tanks, but I think this looks better. After 7 or 8 refueling trips I filled it up, the fuel lifter is slowly drifting into the darkness at the top of this picture. And here is the ground base. Lots of mod parts, from HOME, Kosmos, KW, and Kethane. It was put together with 8 launches. Except for the central component and the fuel lifter everything was built with detachable wheels and landing systems used to move everything into place without adding to the total part count (around 250 parts with the lifter docked). After filling up the orbital station I have another 9000 units of fuel, 1000 units of monopropellant, and 14000 units of Kethane. I'm still not completely happy with it. The central component is poorly designed, the main section is just a useless Kosmos part, so it doesn't hold nearly as much fuel or kethane as it could. And the lifter could hold a lot more fuel. But overall I think it's pretty good.

From your diagram that's not really asparagus staging, that's just one stage feeding directly into the each inner layer. The wiki has a diagram of what it should look like. I assume that when you drop stage 1 all 8 outer engines fall off. In asparagus staging you should only be dropping 2 at a time (from opposite sides). So instead of 3 stages you should have 9, I think. It's a little bit trickier to set it up like that; things can be very unpredictable, but I have made a launcher with 4 layers of asparagus staging, you just have to be careful with ordering the stages. To better track your fuel flow try right-clicking on the fuel tanks during ascent. The inner tank should not decrease at all until all of the outer tanks have been dropped (assuming that the inner engine has the same fuel flow as the outer ones, which yours does). If it starts going down before that then something is off.

Another thing to keep in mind, at least with mechjeb, is that the delta-v values it gives are for atmospheric flight (I assume that means at sea level on Kerbin) and vacuum, but not in between. I can't remember the exact numbers off the top of my head, but I think it takes about 3000-3200 m/s delta-v to get your initial apoapsis up to about 70km (assuming a good ascent profile). A lot of that initial delta-v takes place in the atmosphere, so I design my initial stages to deliver a little bit less than 3000 m/s of atmospheric delta-v. The circularization stage takes another 1200-1400 m/s delta-v, but that's all at vacuum, so it's easier to calculate. I have a few sat-map probes that work out almost perfectly for calculating this. The first stage is just enough to get up to 75km, the second stage is just enough to circularize, the 3rd stage is just enough to get to Duna, or Eve, and the all the fine tuning after that is done with an ion engine. I'll try to launch one of those later today and see just how much delta-v is needed for each part of the ascent. I assume there is an easy way to calculate this based on atmospheric density, ISP, and TWR, but it seems just as easy to monitor how much delta-v is expended at each step.

That's strange about the orange tanks being less stable than multiple gray tanks. I've always found the opposite to be true too. While trying to launch a fuel depo, essentially 5 orange tanks strung together, I tried dozens of times with 10 gray tanks and 5 mainsails on the first stage. Nothing I did could ever make the thing reliable, and different components were failing almost every time. No amount of adding, adjusting, or removing struts (sometimes more struts can make things worse) helped, but just replacing the 10 gray tanks with 5 orange ones worked on the first attempt. Do you always put a small gray tank below the orange ones to avoid overheating? Maybe that is less stable than using 2 big gray tanks.