Troberg

Easiest way: Install MechJeb and see how it does it. Once you've seen it done a couple of times, you'll know how to do it.

How do you place the stacks with such precision? Also, how do you keep it from falling apart?

Engineering challenge: Get five orange tanks (full) into a 100 km orbit with the most remaining Delta V in 500 parts or less. One launch, no docking allowed. Or, if that's too easy, just increase the payload until the rocket starts to fall apart...

When I use the 3x aerospikes, I still use mainsails for the thrust, especially on the first stages. However, once I'm up to speed and at higher altitude, the thrust from the aerospikes is sufficient, especially as I need to carry less fuel. As for control, I still have a few mainsails on the construction, so they provide the needed control. Just for clarification, so I understand you right: If you put decouplers and docking ports to keep stuff together, when you decouple, the docking ports between the parts automatically release as well?

I have thought a bit more on the subject, and I feel that it would be nice with radial decouplers made for long stacks. Have a really sturdy (and proportionally heavy) decoupler that runs the length of an orange tank. That'll be on my wish list for some upcoming version! It's really hard to build large constructions when it feels like the entire construction is made out of rubber... Larger parts of a Duna base. In the future, multiple lander interplanetary missions. Also, I like to have some spare Delta V on my interplanetary missions... That could be part of the problem. On my earlier lifter, I used stacks of grey tanks, as I had problem getting the orange tanks to connect to the radial decouplers. I'll make some experiments later. As far as I can see, performancewise, the grey tanks are equals to the grey tanks. It looks like a very sturdy construction. It could probably be made even sturdier by using hexagonal symmetry, as there will be six sets of docking ports instead of four to hold it together. However, how do you decouple the docking ports to drop stages? Right-click would be too slow. Is it set up for asparagus staging? By the way, try using three aerospikes instead of mainsails on some of the inner stacks. That gives better Delta-V at higher altitude when you don't have to accelerate as much any more. That has been successful for me. Just make sure you keep it symmetrical. Anyway, it seems like Jeb likes it simple: http://rpglab.net/nobackup/fyf5.jpg

I have made a lifter that can lift around 100 tons, give or take. Now, I'm trying to do something that can take a heavier load, say around 200 tons, preferably with enough Delta V left for a planetary transfer burn. However, whatever way I do it, tall or wide, the construction just tends to collapse. The radial decouplers are too weak, and struts does not help (not even lots of them, intelligently placed (I'm an engineer, so I know hot to place struts...)). if I use several radial decouplers to hold the stacks together, it behaves as if only one of them actually couples. If I build it high, the joints between tanks wobble until they fall apart, even with strut reenforcements. I've tried using beams to make it more solid, but it doesn't help. Most of my tries has been with stacks of two orange tanks, usually with two "circles", an inner circle with 6 stacks and an outer with 12. Engines has been either mainsails or a combination of mainsails (for T/W ratio) and tricouplers with aerospikes (for Delta V, when T/W ratio is sufficient). Asparagus staging is used, but they seldom have time to stage before falling apart. Typical take-off weight is around 1500-2000 tons. My old lifter is similar, but with one orange tank stacks, and it works, if one is careful. I've rebuilt various configurations over and over, from the start, so there is no standing oversight/messup in the construction. What am I missing? Some of the constructions, which are about as solid as I can make them with stock parts, fall apart even before the clamps are released, and most fall apart before even reaching 1000 m. This is starting to seriously frustrate me, I've had about 20 failed launches (but no kerbal lost). Is it simply that stock parts are too weak to build vessels of that size? So, hints? Tips? Tricks? Sample working vessels of that capacity that I can examine?

Docking ports or struts, as mentioned above. Then use sepratrons to make sure the unneeded parts moves away from your satellite. I always use sepratrons on stages I suspect that I will abandon in a position where they might follow the main ship. I once had a nasty incident when burning retrograde with a trailing stage ripping off a radially mounted nuclear engine... Just in case, put a small tank and a small engine on the satellite. Problem solved.

It was a 20 minute burn, from a 250 km orbit. What is the "safe burn time"? Is there any rule of thumb for making this gradual change, and will MechJeb still work from an eccentric orbit? Or, should I just add another fuel tank and a Mainsail?

Nope, all engines pointing properly backwards, and it was a controlled burn, it was not spinning or something like that. MechJeb had set the target on the navball about 20 degrees off retrograde. Yes, I should have noticed that, but I have grown kind of lazy and trust MechJeb. Heck, with a ship manned by MechJeb and the real Jeb Kerman, what could go wrong?

I was trying to use MechJeb to transfer from Kerbin to Duna. It set up a manouver node which looked just fine, so I told it to execute it. Then, as it would be a long, slow burn with nuclear engine on a heavy ship, I went and cooked dinner. When I come back, I see that it's burning more or less retrograde, where it should have been burning more or less prograde, so I'm in a steep descent towards Kerbin at some 80 km altitude. I just barely managed to fix it. If I had been a somewhat slower cook, Jeb would have been toast. So, what went wrong, and more importantly, how to avoid it in the future?

FAR? The only mods I use are MechJeb, HayStack, Subassembly Loader and Docking Struts.

I use that a lot, but it also tends to mess up the staging a bit. All Stage 0 from all parts get mixed up as one Stage 0, et cetera. A bit annoying when you have a very complex 79 engine asparagus setup (with separatrons for each stage), as it takes a bit of time and is pretty error prone to sort it out. I would have prefered if the stages from the subassemby were simply added after all the other stages. Then I maybe have to drag them around, but I don't have to sort out every single part.

OK, I thought termainal velocity, in this case, was the intended orbit velocity. Still, I have a rocket with a 2.5 - 2.7 T/W ratio in the first stages (it's intended as a heavy lifter, but most lifts I do aren't very heavy...), and it reaches 200 m/s quickly. Still, it continues to run full throttle (or rather, 95 % to prevent overheating), even with "limit to terminal velocity" active. If I run it on manual, the same rocket can keep a steady 200 m/s on 30-35% throttle, no problem. So, in my head, things still don't add up. I'll do some tests with a lighter rocket, so I get a framerate that doesn't look like a slideshow and see what happens.

OK, but no way to limit by ascent speed and atmosphere? It seems a bit fiddly to continually change %. Acceleration is not what I want to limit. Terminal velocity is not what I want to limit either, I just don't want it to keep trying to push above 200m/s at low altitude.

First of all, apologies if this has been asked before, I have not read the entire 153 page thread (that's about a typical novel...). Is there a way to limit thrust on the Ascent Guidance module? As it works now, I have a rocket that can easily manage at 1/3 of full throttle through the thicker atmosphere at lower altitudes, but MechJeb insists on going as full throttle as overheating restrictions allow, wasting lots of fuel simple pushing air out the way, without actually gaining much speed. It would be nice if the rate of ascent was limited by atmospheric density.

Yep, that's pretty much how I did it.

Sorry, no screenshots, and I kind of made a very precise orbit (in other words, crashed into it) when I was going to rendezvous with the station to add another module, so it'll take a while to get the things in space again, especially on my underspeced computer. Maybe later. I had some fun, though, trying to save two surviving EVA kerbals (the station was pretty destroyed and the command capsule in a decaying orbit, so I sent Bill and Jeb EVA and launched a rescue mission). Managed to pick up Jeb, Bill tried a suit-only re-entry and failed.

I've tried to do stuff like that, using a heavy lifter rocket (I would guess that beast can bring a payload of some 200-300 tons into orbit. Weighs around 800 tons without payload and a T/W ratio of about 2.5 all the way up into orbit, with a delta V of about 14000 or so without payload. Only problem is that it takes over an hour to orbit, due to computer performance problems...) to launch multiple vessels at once, such as a space station section with four small ships docked as escape pods, or a larger interplanetary vessel with several heavy landers (the idea is that they should be able to go to most of the easier places, land, start again, return to the "mothership", dock and transfer the crew, abandon the landers and then go home). However, I run into a problem. The staging gets messed up. It can't keep track of the staging separately, so, for example, when I launch an escape pod, all the stages have been joined into one. Instead of just: 0: Parachute 1: Decouple tank/engine 2: Start engine, fire separatrons (to blast it clear from the station) I get: 0: Parachute, decouple tank/engine, start engine, fire separatrons Now, that's not exactly what I wanted, and certainly not what I wanted to fiddle around with in an emergency. Now, if I first send up the space station part, then the pods one by one and dock them, it works. But, when I build it all in the VAB, it essentially becomes one vessel, and when decoupled, starts to behave strangely. How to fix it?