capi3101

You've got a fuel loop going on; if it worked for you before, that was luck. Check out MiniMatt's link for workarounds.

Push comes to shove and nothings working, try attaching a cubic octagonal strut (one of the little girder-looking things) to the central stack and running the fuel line to it. Cubic struts pass fuel (at least I think they do; barring that, use a BZ-52, I know those pass fuel but they weigh a lot more). EDIT: Hang on - for some reason I thought you were talking about radial decouplers; didn't realize the problem was with a stack decoupler. That's what I get for not looking at your picture sooner. Okay...try SCE to AUX. So what you could do here is ditch the fuel line entirely and in the VAB set up an action group with the decoupler to "Enable Crossfeed". Activate the action group as soon as the physics engine releases your rocket. Alternatively, you could try the cubic octagonal strut trick I mentioned earlier. And worst case, try a senior docking port - you wouldn't need a corresponding port above it. Again, you'd need to set it up to decouple as an action group. Might also try one of the large stack seperators to see if you get any improved results. I do have to question why you would want to set your staging up in that particular way. As a rule an engine in the center stack provides your rocket with some stability (meaning it doesn't spin around like a damn blender when you go to launch the stupid thing). If the idea is to conserve fuel for a later engine, you could get the same effect by putting the big fuel tank below the decoupler - it'd give you a much simpler setup.

I haven't had problems with fuel lines connecting to decouplers in 0.21 and I build asparagus fairly regularly, so it's likely to be a question of where you're attempting to make your connections. I usually steer mine well clear of the decouplers on principle. I will caution you never to try to feed a fuel line through the center of a Hydraulic Detachment Manifold...it may look like it connected to the target tank, but I guarantee you the game will count it as stuck to the decoupler...

@KerbMav - you could determine the time with a third-order kinematic equation, assuming full thrust on your engines and accounting for the target's gravity, accounting for the rate of change of mass of the ship (i.e. the rate of jerk), and knowing both the starting and ending elevations. Oh, and your initial velocity; final (desired) velocity is zero, of course. Yeah, there's a hell of a lot of math there. It's vector math too, I should add. At least it reduces to two dimensions...

To my knowledge, none of the actual anomalies changed positions with the 0.21 procedural terrain update...which was bad, because a number of them wound up buried (my understanding is that the ancient Kerbal temple is now a good 2-300 meters below ground). I think KSC2 is still there because someone asked about it a week or two ago, but I've yet to go there my own self (it was the target of my Storax Sedan 7 tests...none of which successfully put a rover on Kerbin). I doubt very much that the valley itself is still present.

@Vanamonde: ...or at least, little green guys. Last night I did the transfer and correction burns for the Storax missions. Owing to different ejection angles and a three day departure difference, Storax Sedan arrived at Duna a full 30 days before Storax Anacostia (which is still en route). Since Sedan is the landing site scouting mission, I had absolutely no problems with this. Went ahead and landed the Sedan mission. Despite all the structural failures with the payload coming off on chute deployment on Kerbin, the design worked exceptionally well on Duna. The final landing would've been 100% successful had I not landed on a slope...tilted the skycrane over and broke off the engines. Probably a good thing that one was supposed to be a one-way trip. So now I can add Duna to the list of worlds where I've deployed 'Hounds. My two 'Hounds, Malaise and Lack of Prospects, are currently searching for the anomaly indicated on the southern polar cap. I didn't have much additional time after the landings last night, but so far the two rovers have travelled about ten kilometers from the Storax Sedan landing site. Both have already popped a tire (front tire on opposite sides) and Lack of Prospects hit a bump hard enough to trash one of the sci-beacons she's hauling, and I've lost a few too many Negative Gravioli sensors, but otherwise things are going well and I anticipate arriving at the site soon (Lack of Prospects is currently at about 49Sx169W). By soon, of course, I mean "soon enough to mark a bullseye for Storax Anacostia", which is still thirty days off...

@Xeldrak: I'm beginning to wonder about that... Transfer's under way on the mission - pretty sure I'm going to get exactly no points for arriving early...

Gilly so far has been the only moon in the Kerbol system that I've had to thrust toward while trying to land...only takes 70 m/s of delta-V to land and launch again, easily within the abilities of a Kerbal space suit. Walking around on Gilly is...problematic. As for Pol, Johnno's given you the best advice so far - plan the mission backwards. Only other thing I could suggest (and this is just me shooting my mouth off here; I've sent exactly jack to the region near Jool) would be to stick a refueling tanker in Jool orbit as a separate mission. Your mission profile then becomes 1) launch, 2) transfer to Jool, 3) rendezvous with refueling craft to refuel, 4) transfer to Pol, 5) send down lander, do business and come back up, 6) transfer back to Jool, 7) rendezvous with the refueling craft to refuel, 8) transfer back to Kerbin. That's an extraordinarily rough sketch and there may be merit in putting the refueling tanker over Pol as well (to avoid having to transfer back to Jool before heading home).

A single one by itself isn't terribly strong, true. That's why in pre-0.21 you had folks with docking ports mounted on tri-couplers all the time. Of course, the tri-coupler came with its own set of headaches (namely the fact that it wouldn't sit flush with a big fuel tank on the narrow end, necessitating additional struts - and the additional headaches associated with docking more than one port at once), but at the time it was still the best option. The n-adapters that came with 0.21 go a long way towards fixing the extra strut issue. And then there are Seniors - I'm not entirely sold on them, to be honest, but then again it's been a while since I've launched a proper interplanetary mission.

Yep. Screwed up this one myself recently... Here's what you do: 1) Before you go putting the adapter on for your rockets, you want to build the bottom first. Stick a tri-adapter on your stack, then attach three Clamp-O-Trons on that. 2) Pull the adapter off the stack, flip it over and set it aside for the time being. 3) Stick another tri-adapter on the stack. Add your engines (you're working with LV-Ns, so watch how you line them up!), stick decouplers on the bottom of them, then docking ports on the bottom of the decouplers. 4) Pick up the bottom piece you built earlier and attach it via the docking ports. It's the old "extra rigidity through multiple docking ports" trick. When you get out to the pad, the game will only count one of the ports as attached, but as soon as the physics engine releases it the other ports will suck each other in and lock down. The addition of the decouplers allows you to jettison the whole thing as a normal stage when the time comes.

@Space_Pirate_R: the 9.81 m/s figure is used as a conversion constant for specific impulse into effective exhaust velocity. You can read up on it at Wikipedia. In how it's used, it is measured in respect to the effect of surface gravity of Earth on objects in vacuum (a concept known as standard gravity). Beings on other planets would probably use their own standard gravity values - whatever floats their boat, right? Of course, it'd make no sense for them to use meters and seconds; they'd have their own designations. But they would still have their own units of measure for distance and time, and that's really what matters. There'd be conversion factors - just like there are on earth between metric and Imperial units, for example. Kerbals use metric. That's kinda suspiciously convenient, like they're actually under the control of a game company based in, say, Mexico or something...

Didn't do much. Built test rockets to prove myself right on how adapters work...managed to prove myself wrong in the process. That was pretty much it; had other things going on last night. Began thinking about how I want to go about doing the Eeloo challenge.

I usually ditch mine with the lighting of the second stage. At least that's the way I set it up with the Storax Anacostia 7 rocket (the treehugger Apollo-style Duna mission I've got in progress); with the Castle Romeo 7 (Munar Apollo-style), I forgot to ditch the thing entirely until I was in orbit... All stock; just a decoupler, a modular girder adapter and twelve Sepratrons tied in with the Abort action group (the decoupler in the action group is the one holding the CM to the rocket; there's a second decoupler that will jettison the assembly from the stack). A second action group jettisons the tower post-abort and a third activates the descent chutes. I have pictures of the system in action, come to think of it: Damn good thing I put it on the Storax Anacostia - the second and third launch attempts suffered RUVD during the first stage and I'd have lost my three musketeers for sure without it.

Built a couple of test rockets last night; tests showed y'all were right. Certainly explains why the decouplers were exploding... My apolgies, y'all. I wouldn't have argued the point if I hadn't thought I was right. PetWolverine's solution is probably the correct one...I didn't test it out last night. Probably what you could do is go ahead and build the bottom part first - the adapter with the ports - then take it off your stack, flip it over and set it aside. Go ahead then and build the upper part - adapter, engine, decoupler, port - then grab the bottom part and stick it on. The ports give you the connection; the decouplers let you slough the whole thing off as normal. Like I said, I haven't tested this configuration out and I've already proven myself wrong in this conversation, so take this advice with a big grain of salt.

6,089 is right in vacuum, yes. And at launch, you'd have 4,684 m/s (because the 909's Isp is different in atmo).

Well, I'll check my designs again, because I have done this. Twice. Is there no difference between an n-coupler and a n-adapter? I'm talking about using adapters...

Beg to differ with you on that - You can put a docking port below a decoupler or seperator and it will attach... Wait, that not what I said in my original post, was it? My apologies. If you're using docking ports to hold the ship together, you will need to put something above them like a decoupler or seperator; it will give something for the docking port to couple to and generate a fairing for the engine. Time comes to cut it lose, you can just right click and "decouple node" and off it will go. You can later right click to remove the decouplers/seperators and the fairings they generated manually. I mainly just mentioned docking ports as an option; they will attach to other bits without a docking port above them - they just won't reattach if they get cut loose. I get the impression I'm not explaining that well...look at this. And know that yes, you can get that narrowed back down to a single stack. I've done it myself, but as they say, pics or it didn't happen, and I don't have any at the moment...

Wilt57's got it. Only thing I'll add is that to get into position for aerobraking, you might need to consider radial burns once you hit Duna's SOI. The earlier you do them, the less delta-V you'll have to expend. Yes, I know radial burns are inherently inefficient, but if the choice is between achieving orbit and getting flung back out into interplanetary space...

Uh.......I'ma thinkin' this needs to be in Fan Works......

You mean an adapter engine sandwich? I've gotten them to work with some success (the decouplers have a tendency to explode when they're activated but so far all that's done as been to blow up fairings, leaving engines intact. Here's what you do: 1) Stick the adapter on the bottom of the stack. 2) Set your symmetry to match the adapter type and make sure snap-to is on. For example, if you're using a quad adapter, use 4x symmetry. 3) Attach your engines. Use shift-Q and shift-E if they don't want to snap on until all engines turn green. 4) Slap the decouplers/seperators/docking ports on the bottom of your engines. (Use struts later if you go with ports). 5) Flip the other adapter upside down (WASD, twice on the same key you pick) 6) Attach it to the decouplers. I'm actually using this at the moment on my Apollo-style Duna mission; I haven't taken screenshots yet but I can take some later tonight and post them if it'd be at all helpful to you.

If you've got the figures, you just plug them into the equation. Okay, practical example time. My Fireball 7 rocket on the pad has an Isp of 225 (RT-10s only in that stage to keep things simple; there are seven of them but of course it's the same engine all around so 225 is what you use). The rocket weighs 104.1725 tonnes before the stage is lit at 81.44 when it's dry. So plug it in: delta-V = ln(104.1725/81.44) * 9.81 * 225 = 543.3844 m/s. Thus my launch stage has 543.4 m/s of delta-V. Next stage: after sloughing off the SRBs, the rocket's next stage is 77.47 m/s full and 29.47 dry. She's using LV-30s/45s at that point, which have an Isp of 320 (bit higher than that but I use the low end for planning purposes). Plug it in: delta-V = ln(77.47/29.47) * 9.81 * 320 = 3,034.093 m/s. Add that to the previous stage and so far the Fireball's got 3577.478 m/s. Just keep doing that for all the stages of your rocket. Easy peasy. That natural logarithm (ln) might be tricky...you'll need a scientific calculator to figure it up unless you happen to know how to calculate it (which I don't know if anybody does in this day and age). MS Excel also has the command =LN() which will do the same thing.

Question for the sake of clarification - if I launch a space station to Eeloo, does it need to go on the same rocket as the Kerbals? Or can I launch a bunch of payloads, assemble them over Eeloo and call it good (provided it meets the criteria of a space station as laid out in the rules)? I can only land one manned flight on Eeloo, is that right? Is there a limit on the number of unmanned flights I can put on Eeloo? Seriously thinking about doing this challenge....it sounds hard yet fun. Plus Eeloo's one of those places I have yet to visit.

Yeah, the parameters for Kerbol are all over the place; even the wiki mentions that there are no fewer than four possible stellar classifications into which it could based on its parameters (G-type, K-type, M-type, or sub brown dwarf). Kerbin orbits at a distance of about .09 AU from Kerbol and is habitable - that would be consistent with an M8V star, which would have an ecosphere from about 0.077 to 0.113 AU (11.55 to 16.95 million kilometers) give or take. You probably could just go ahead and use those figures and no one would be the wiser. Jool/Laythe are at .458 AU, incidentally... Bear in mind I'm swiping this information from an RPG, so take about the appropriate amount of stock in those figures. It's a well-researched RPG, if that helps. Frost Line at .159 AU, Roche Limit at .009 AU (Moho's safe at .035), Outer Planetary Radius at 10.56 AU.........Tidal Lock Radius at .463 AU...................

Without being able to look at your screenshot, I'd suggest taking another look at the way you've got your fuel lines connected in the VAB. Make sure they're all making contact between the proper set of fuel tanks; if one's connect to something like a wing or a side tank, you'll get un-even fuel drain. Also make sure they aren't being connected "through" another part; I had this problem happened to me once and I was able to trace it back to me trying to run a fuel line through the center of a Hydraulic Detachment Manifold (game counted it as attached to the Mainfold when it looked like it was attached to the tank). Imgur ain't all that bad, just sayin'. I was skeptical about it myself at first but it's really quite easy to use.

Launched Storax Anacostia 7 completely after two failed tries (had some structural issues with the orange tanks that didn't happen in last night's launch attempts). As I'd figured, a slow burn with the third stage was sufficient to get the craft into orbit. It would be nice to figure out how to make a quad-adapter engine sandwich that didn't blow up when you decoupled the lower adapter piece but the ship is intact and everything looks operational. Four days to the optimal transfer window. If Bill doesn't play his Enya CD over the loudspeakers again, all three Kerbonauts might be headed to Duna in a few days. Got started with the Baja Munar Challenge. All I can say is that I don't like the rover design...a definite Mun buggy with a high center of mass. Good thing Jeb and Bill keep a portable Goodyear tire shop in their spacesuits; they've definitely been racking up the frequent flier miles this time around. Probably a good thing this challenge isn't on Minmus... Started eyeballing the Eeloo challenge. That one looks quite difficult and yet fun at the same time.