capi3101

If that gets too bad, I usually just time warp. That's probably cheating, of course...

I agree with pretty much what everybody else has said; you've got a lot of unnecessary lander. Atanar's design would work well. Be sure to start off with a probe chassis on top, that way the Command Pod stays empty for the trip. For the booster you probably could get away with two stages each with a couple of FT-800s, an LV-45 in the center and LV-30s on the sides (say six or so; I'd have to do the math to be more specific). Run fuel lines from the exterior tanks to the interior, add a couple of winglets to the outside and that should do it.

So when's the best time to adjust your trajectory to lower the periapsis close enough to aerobrake, assuming no piloting mods?

Short answer: practice with something a bit smaller than a space station first. -- http://wiki.kerbalspaceprogram.com/wiki/Tutorial:_Gemini_6A_and_7 The main trick is to get the orbits of the two objects you want to do close to one another first; that means having apoapsis/periapsis as close as possible and killing any declination in the orbits (ascending/descending node = 0). If the target's ahead, lower your orbit and vice versa. Watch the intercepts; when they get pretty close to one another, begin tinkering with your orbit to get it the intercept as close as possible. Once you get that to within 500 meters or so, you should be close enough to attempt the rendezvous. From there it's killing your thrust relative to the target (yellow retrograde), then thrusting towards the target (pink prograde) until you get within ten meters or so. Align the docking ports on both craft (preferably on torque thrust, not RCS), thrust forward and off you go.

Uh-huh.......yep................that's a nice space station core you've got there. For your first Mun missions, RoboRay's design is what you want to shoot for. If you want to go fancy with it, replace the center fuel tank with an FT-200, put three or four more FT-200s on the sides and hook fuel lines from the outrigger tanks to the center tank. Put your lander legs on the outriggers. This shortens the overall length of your lander and widens the base, which really helps when you're making Mun landings. Oh, and OKTO/4 PB-NUKS if you want to make a couple of unmanned practice missions first.

Let's play it conservative: Kerbin - Jool Intercept: 1915 Jool Orbit: 2630 Jool - Laythe Intercept: 1600 Laythe Orbit: 780 Landing/Launch: 2800 Laythe Orbit: 780 Laythe-Jool Intercept: 1600 Jool Orbit: 2630 Jool-Kerbin Intercept: 1915 TOTAL DELTA-V: 16,650 m/s There's a couple of fudge factors in there - you probably don't need to go back to Jool after you've lifted off of Laythe; that's 4230 you could apply for other purposes or ditch. You should take SunJumper's advice on the chutes; otherwise the launch/landing is going to take more than 2800 to pull off. Shoot for 120 km to aerobrake at Jool (that'll put your apoapsis close to Laythe's orbit) and 50k for Kerbin. I assume you could aerobrake with Laythe itself but I don't know the altitude off the top of my head. Caveat: I've never been to Laythe (as is obvious from my ribbons); take my advice with more than grain of salt. Good luck.

I've done docking maneuvers low and high; in my experience, there's not much difference in the particulars. That said, I like most people go for 100 km; it's a good standard orbit height, it gives you room to adjust your orbit both up and down and you don't have to plan for a large booster to get it where it needs to go.

If you're really interested in practicing without a live Kerbal on your lander, I'd suggest using a Probodobodyne OKTO probe with 4 PB-NUK Radioisotope Thermoelectric Generators attached as your command pod. Unmanned; nobody dies when you plow that thing into the Mun the first dozen times, and when you think you're ready you can swap it out with a Mk1 Command Pod - it's the same mass as the OKTO/PB-NUKs. If you go the docking/refueling route, I'd suggest practicing with the Gemini 6A/7 tutorial on the wiki. It'll teach you everything you need to know. Really, docking's no biggie as long as you take it slow.

Never thought of that...and it makes sense: something being pulled is inherently more controllable than something being pushed. Turning might still be an issue; then again it might not. Something new to try.

Yep. That's what I use.

Docked ships act as one craft. You will need to shut down any engines you don't want to use during your burns manually and make sure your control point is in the direction you want to travel; if you start your interplanetary transfer burn and notice your speed going down, it's because you've got a control point that's pointed in the opposite direction you want to go. Pick another one ("Control from here"), reorient your ship and try again. Couldn't tell you how many times I've done that one. The RCS thrusters will act as one while your craft are all docked with one another to turn the whole shebang in one go. Keep plenty of fuel in each RCS tank and you should be good to go. Incidentally, RCS is a good way to make subtle but significant changes to your transfer burns; it can make all the difference between aerobraking in Eve's orbit and landing on it by mistake... Parts connected by single docking ports will have a tendency to wobble under thrust; bear that in mind if your design gets to be long. Most folks get around this by sticking more than one docking port on their parts; that can create its own headaches. Good luck.

Alright...so rendezvous isn't a problem; it's the actual docking. Here's how I do it: 1) Close to within 20 meters. Bring the relative velocity down to zero. 2) Aim towards the target. Accelerate to 0.5 m/s and return to zero when you're at ten meters. 3) Switch over to the other ship. Target your first ship and turn to face it. Try to do this on command pod torque if at all possible; RCS may produce undesired relative velocity. 4) Switch back to your first ship. Make sure you're facing the target (again, do this on torque thrust if at all possible). When you're facing the target, accelerate to 0.3 m/s relative. 5) If it looks like you're going to miss, slow to zero and realign. Be patient. 6) When you get within a meter or two, the magnets will start attracting one another and pull the ships together (provided they're facing outward; also, shielded ports need to be opened well before you get to this point). At that point you just need to sit back and relax; it may take a while but the ships will finally settle down. Other than that, all I can say is good luck and keep trying. Might try an F5 quicksave when you get to your final approach; if you screw it up, hold down F9 to try again.

Count I've heard is 15 PB-NUKs to power 1 Ion Engine. Problem with ion propulsion is the lousy thrust. Just as an academic exercise, add up all the mass of everything you'd need to keep an ion engine running. Take the thrust you'd get and divide it by that mass; what results is your acceleration in m/s^2. You'll find it sucks. Badly. Like leave your computer on overnight to perform a transfer burn kind of suck. You'd probably be better off with LV-Ns unless you're planning to have a very small probe for your payload.

There's a good tutorial that goes over how to rendezvous and dock on the wiki, the Gemini 6A/7 Tutorial. Someone a little while back also posted a ship design whose purpose was solely to practice docking; I don't remember where that is and I'm hoping it didn't go down in the Great Coffee Spill last month.

Alrighty: found the problem. I had put the interior fuel ducts in the open space in a set of Hydraulic Separation Manifolds. Game wasn't counting them as connected to the interior tank. Moved 'em up a bit and they worked fine. Next UVD from the wobble getting too severe and causing the center engine's lower fuel tank to break off. Struts solved that one; things worked a bit too well after that - the second stage tanks still had gas in them at SECO, so I kept 'em on for the orbital insertion burn, despite the fact I had made no provision for steering with those tanks still attached out outside the atmosphere. I had sufficient RCS thrust available to get turned for the burn. Tanks in the second stage ran dry during the OEB; the subsequent attempt at stage separation caused the next UVD. I'm out of time to make another launch attempt tonight; next chance I get I'll shut off the second stage engines and separate them when I'm supposed to. If I get another UVD from that I may attempt the orbital insertion burn with them still attached; see what that does. Anyway, thanks for your help, y'all.

I've done a successful landing on Duna with a fifteen-tonne lander using three Mk16s. You do need to apply some thrust on your descent stage to get it slowed down; not generally as much as you would for a Mun landing, though.

I'm positive they're flowing the right direction; I include fuel ducts with almost all of my desigs, so I am pretty well versed in how they function. I did the math on that one. TWR at Stage 2 seperation is 1.2 with the Mk-55s and 0.9 without; it's the whole reason why I included them in the first place. I actually had given that idea some thought; I've noticed a lot of wobble in the central engine during takeoff, no doubt due to the plethora of gimballing engines I've got on the design. I haven't crunched the numbers on putting in a cluster yet; might be worth investigating. I am familar with Temstar's heavy booster designs; whole reason why I'm trying a 120 tonne payload. I finally know it's in the realm of possibilities... "Onion"-staging, huh? I'll remember that. Meantime I'll do what y'all have suggested and report what happens.

So here's one I don't understand...I've got "ringed" asparagus staging going on between my stage rockets if I understand the term correctly; the third stage feeds off the second stage which feeds off the first. 8 mainsails in the first stage, 8 mainsails in the second stage and the third stage (the central stack) is one mainsail with 8 Mark 55s (without which the third stage TWR would only be 0.9 if I've done the math correctly). I've checked the fuel ducts and they're all running in the right direction. Launch at 80% thrust and the first stage runs out of gas just before 10k following a fuel-optimal ascent profile; I eject it and throttle up. Twice now, when I get to about 14,000, the center engine shuts off because it's out of gas. You know, my third stage - the one that's supposed to make the orbital insertion burn and should be drawing off the fuel supplies of 16 mainsails. Any ideas on what might be happening? I'll try to post the .craft file and some screenshots in the near future; still haven't found a repository I like yet. Maybe some crappy ASCII art would be helpful? â–‘ â–‘ â–‘ ââ€Ëœ ↓ ââ€â€ â–“ â–“ â–“ ââ€ËœÃ¢â€ “ââ€â€ â–‘>>â–“>>â–ˆ<<â–“<<â–‘ ââ€Â↑ââ€Å’ â–“ â–“ â–“ ââ€Â ↑ ââ€Å’ â–‘ â–‘ â–‘ â–‘ STAGE 1 â–“ STAGE 2 â–ˆ STAGE 3 EVERYTHING ELSE IS A FUEL DUCT

You really shouldn't try to jinx yourself like that... show-off

Quick note for a substitution - assuming you've got a Mk-I on your rocket right now, a Probodobodyne OKTO and 4 PB-NUKs have the same mass; swapping one out for the other = no net effect on delta-V or TWR.

http://wiki.kerbalspaceprogram.com/wiki/Controls

So here's one I don't understand...I've got "ringed asparagus staging" going on between my stage rockets if I understand the term correctly; the third stage feeds off the second stage which feeds off the first. 8 mainsails in the first stage, 8 mainsails in the second stage and the third stage (the central stack) is one mainsail with 8 Mark 55s (without which the third stage TWR would only be 0.9 if I've done the math correctly). I've checked the fuel ducts and they're all running in the right direction. Launch at 80% thrust and the first stage runs out of gas just before 10k following a fuel-optimal ascent profile; I eject it and throttle up. Twice now, when I get to about 14,000, the center engine shuts off because it's out of gas. You know, my third stage - the one that's supposed to make the orbital insertion burn and should be drawing off the fuel supplies of 16 mainsails. Any ideas on what might be happening? I'll try to post the .craft file and some screenshots in the near future; still haven't found a repository I like yet.

With the great forum nuking last month, the boards currently do not have attachment functionality. You'll have to put your materials on another site and link them in on the forums here. A lot of folks are using dropbox and imgur.

Pretty much what I said earlier; payload's just under 120 tonnes. I've designed a TSTO booster for it using the orange tanks - looking at TWRs of 1.75 on the first stage, 1.68 on the second, and 1.24 on the third. total mass at launch is looking at a little over 1500 tonnes with about 4601 delta-V. So...I've built this design at this point and I didn't know you could stitch the tanks together, so as y'all can imagine I've been treated to some fairly spectacular unplanned vehicular disassemblies this evening. I think my record for skipping a Standard Canard across the KSC is maybe half a dozen bounces so far. You know it's bad when the TT-18-As get knocked over; yet the Probodobodyne OKTO sitting at the top of the third stage survived. Even still had a PB-NUK attached. Actually did get the design into the air once and it did pretty well up until first stage separation. That's when I realized I hadn't put any control surfaces on the second stage... Good thing that A) the designers have yet to account for radioactivity from exploding PB-NUKs and LV-Ns and I was doing all this in the "Construction Basics" tutorial, so I didn't clutter up my persistent game with moar junk...

Okay; I've actually got several stacks of two planned in my design... When you say I should "be prepared to add a dozen struts", is that between the two tanks or between them and the tanks surrounding them? I.e. can you put struts between two tanks with one on top of the other? I've tried and haven't had much success in that regard.