ginsweater

Huh, actually the LKO capacity of my "standard medium lifter" that I use all the time is just about 60 tons. You can see it in this album lifting a 54-ton spaceplane into a 350/90 elliptical orbit - those craft files are over in its thread if you want to see how it's put together. If I need a bit more capacity I can add another half-height tank to the seven main stacks and it still lifts off without trouble. ...yeah, I call it my "medium" lifter. Do I have a skewed view of these things? When 0.17 first came out and I assumed I would need insanely huge landers for other planets I built this 1200-ton tower of lag and explode which, on the rare occasions when it holds itself together for an entire launch, pushes 130 tons to solar orbit. (Not posting the .craft for that one because someone might download it and I don't think I could live with myself if that happened.)

Yup. I think it's because a rocket without gear or ladders doesn't look wrong - unlike a rocket without, say, engines. And so I end up flying lots of "Apollo 10" missions - get there, get within a few hundred meters of the surface, then say "never mind" and go home for more parts.

I humbly submit my Laythe-roundtrip detachable-wing spaceplane and its little nuclear brother. They're in a thread over on the Exchange: http://kerbalspaceprogram.com/forum/showthread.php/24069-Detachable-wing-spaceplanes-capable-of-Laythe-roundtrip-the-Icarus-and-Nuculus

Okay, I am so inordinately proud of this ship that I can't bear to leave it hidden in the challenge thread - even though it's kind of tricky to launch, and it turns out to have the most common name in all kerbdom, I'm going to give it a thread. This is a spaceplane that detaches its jets and wings just before orbit - hence I decided that this would be my Icarus, because it flies high and loses its wings. By staging, it manages to bring just enough delta-v to Laythe orbit to get the cockpit home to Kerbin. Here's the full imgur album of its maiden flight: http://imgur.com/a/8rN6i#0 In order to manage a strict "no nukes" policy, the base craft has a very underpowered final stage and so it requires considerable luck to get home from Jool. And so I am also introducing here - the Nuculus I! In abject defiance of mild environmentalist protests and massive outraged games-should-be-hard-dammit-ist protests, the Nuculus offers a NERVA engine and well over 3 km/s of delta-V on the final stage - enough to allow an easy return from Jool at the cost of a 7% weight increase and correspondingly more difficult landing and takeoff. Trainer versions (plane only, no boosters) of both planes are also available - so you can try them out and practice your landings on Kerbin. (Or just crash the Nuculus trainer on Moho - it has a pretty good shot at making it there all by itself!) I used my weird customized Kerbal Engineer Redux for design and flying, but I (think I) removed the parts for posting, so the .craft files below are all stock. Watch out for the Space Cthulhu when you're on the pad. I decided to make this a freestanding rocket (no space for the towers) and it often loses an engine or two if you timewarp before launch. (Just end the mission and restart.) The Jool transfer window happens when Jool is 96.58 degrees in front of Kerbin. (Thanks, ksp.olex.biz!) Your ejection angle if you go into an 85-90 km parking orbit is 114 degrees from Kerbin prograde. Note that Jool moves about .12 degrees per hour, so if you launch when Jool's right at 97 degrees, that'll give you a couple hours to get into orbit and escape Kerbin. I like to launch just before sunset, both because it's pretty and because I achieve orbit at about the right spot for my escape burn. 1) Landing gear up. SAS on. Throttle to full. 2) Launch. 3) When the first stage SRBs burns out, stage once to drop them and again to light the second stage SRBs. 4) Stage again to drop the second stage SRBs. 5) At 10,000 meters, begin a gravity turn to 45 degrees. BE CAREFUL. If you turn too fast, the spaceplane wings will catch the wind, and you'll lose control. 6) When the liquid boosters burn out, you should have an apoapsis of 85-89 km. Cut the engines and begin your coast. 7) Stage to separate the liquid boosters. MAKE SURE the throttle is at zero when you do this, otherwise you're likely to crash into them. Puff your engine (tap Shift, count to two, press X) to help clear the spent tanks. 8) Pitch to horizontal. Throttle back up about 30 seconds before apoapsis. Achieve orbit. 9) You'll have a little bit of fuel left - I suggest firing it off when you pass your ejection angle; it'll raise your apoapsis to 300-400 km. 10) Stage to drop the orbital insertion booster. 11) The interplanetary stage is four strap-on boosters - they should have plenty of fuel to get you to Laythe if you aerobrake at Jool. (119.5 km Jool periapsis should do the trick. I can't give you advice on a Laythe aerobraking altitude - it seems to be between 20 and 25 km. You can do a direct descent if you have to but it's really scary.) MechJeb can almost fly this craft to orbit, but it doesn't know that it has to throttle down when detaching the liquid boosters or it'll hit them with the main engine. So to fly using MechJeb, I recommend the following: 1) Edit path, set Turn End Altitude to 40 and Final Flight Path Angle to 40. 2) Set Orbit Altitude to 85km. 3) Auto-Warp Toward Apoapsis to OFF. 4) Launch - you can stage the SRBs manually or let MechJeb do it. 5) When MechJeb shuts off the engines to coast to apoapsis, there should be only a tiny bit of fuel remaining in the boosters. Stage manually to drop them during the coast. 6) Fly normally. 1) Stage to drop your interplanetary boosters. Don't wait too long; if you do this in the atmosphere they're liable to hit something. 2) Set the plane at an angle of attack of 20-30 degrees and switch on SAS for re-entry. Once you hit atmosphere, don't touch the controls until you get under 300 m/s - the plane will be very unstable. 3) The jet engines will have switched on when you dropped the boosters - if you're going to hit water, you can always throttle up and fly to a continent to land, but you'll have that much less fuel for liftoff. 4) Continue to glide until you start to see your shadow, then flare to a 30- or 40-degree angle of attack. Try to get your surface velocity under 45 m/s if you can. 5) At the last moment, let your nose start to come down so you don't lose your jets when they hit the ground. 6) Don't hold down the brakes or you'll tip over; tap them to slow down gradually. Re-engage the SAS, or don't - it's up to you. 7) Good luck. 1) Throttle up your jets. Release the parking brake if it's set. Try to find a liftoff direction that sets your wings level - it makes it a lot easier to recover from bumps. 2) Be alert for bumps. You can recover - especially if you have a joystick - but you need to be quick. 3) At 100-120 m/s, start to pull up. If you go over a ridge at this point, you'll be airborne - be ready. 4) If you're not already heading east, turn. Pull up to 45 degrees and set the SAS. 5) Wait until your surface velocity stops increasing, then stage to fire the central engine. 6) The jets will still have a bit of power before they're totally useless. Wait until your vertical velocity starts to fall. 7) Stage to drop the jet engines. The plane's nose will jerk down from their backwash - don't worry, let the SAS recover. 8) Wait until the two side rockets burn out. You should be in a high suborbital trajectory. 9) Cut your engines to coast, and stage to release the wings. Use the final engine to establish orbit. 10) If you're using the nuclear final stage, you should have enough fuel to leave Laythe orbit, descend to a low periapsis over Jool, and burn to a Kerbin intercept. If you're using the LV-909, you'll have to be creative. Good luck.

I like this landing site: It's close to the equator, reasonably flat for a long way, and once you're down you can drive over to one of the nearby lakes to do SCIENCE! The easiest place to land, though, seems to be the polar ice caps since they're totally flat.

The first rule of Kerbal aerodynamics is: More wings are always better. (The second rule is: as long as they're behind the center of mass.) Control surfaces count as wings for the purposes of "should I add more" - they're a compact way to get lift even if you don't need them for control. But if you have too many horizontal control surfaces, your plane will respond to your input so enthusiastically it may be hard to keep upright. I recommend a relatively small plane, with the center of lift well behind the center of mass. That will make it stable, and stability counts for more than maneuverability if you're just designing the plane to land - it will be less likely to tip over when it inevitably hits a bump. I was able to get my own plane down to about 45 m/s for its landing by flaring (pulling to a high angle of attack) right before touchdown; that speed is a tough landing but not impossible. This guy managed to land and survive at 70+ m/s but IMO that's insane. If you're not planning to return to orbit, you'll have an easier time the less fuel you take along; a bit of jet power is handy to avoid a water landing but I wouldn't take a whole rocket tank full of fuel. 100 liters or so is plenty.

After many, MANY failed attempts, and with, I confess, a considerable amount of savescumming, I MADE IT!! I used a spaceplane that dropped off its wings just before achieving Laythe orbit, becoming a more-or-less standard "one tank return pod." That way I could return about 1700 m/s of delta-V to Laythe orbit without needing a huge heavy spaceplane. I scouted a flat surface near the equator: and after MANY attempts, I managed to land. As a bonus, the landing site was near a lake, so I drove over (thankful for my past Mun rover experience) and Jeb took a dip. The full album: http://imgur.com/a/8rN6i#0 This isn't a claim to have accomplished the challenge as I used Kerbal Engineer Redux (actually my own customized version of the 0.2 release - I added inflight delta-v, mass, and planetary angles myself) both to design the ship and for information display during flight. No automation - it's all hand flown (using an X360 controller for the tricky parts) - and it doesn't affect the flight properties of the ship, but it means the rocket has one non-stock part. On the other hand, the design uses no nukes and no aerospikes! So I can still claim personal triumph. Craft files attached (with the nonstandard Engineer part removed so they're all stock) if anyone wants to try them. The "trainer" is just the spaceplane by itself - I practiced flying and landing it on Kerbin before taking it all the way to Laythe. Pad weight is 433.71 tons (244 parts); the spaceplane stage is 23.2 tons; the Kerbin return stage is 7.1 tons and (in this mission) achieved Laythe orbit weighing 6.36 tons.

Project "Spaceplane On Laythe" is not going as well as I might like (NEED MORE LIFT! NOW MORE FUEL! NOW MORE LIFT AGAIN! ) but damn if it isn't producing the prettiest KSP screenshots I've ever taken.

Second the recommendation for Intro to Space Dynamics. Orbital Mechanics by Prussing and Conway has very good coverage of patched conics (the method KSP uses to simulate orbits) if you want to get really deep into the math. It's way too expensive on Amazon, but if you live near a university with an engineering program their library will probably have a copy you can look at. There's also this ebook at www.astronautical-engineering.com which is also way too expensive, but you can read 10-page samples of each chapter and they're fun reads. I'd particularly point to Chapter 7, which has a discussion of the optimal speed at which to ascend out of an atmosphere with the minimum drag losses - I actually managed to save few hundred extra m/s of delta-V getting my interplanetary lifter into orbit by applying the math in that sample. One of these days I swear I am going to sit down and write a plugin to set up Duna/Eve slingshots.

I'm away from my computer this week, so it's been a while, but I still want to answer - That's the fourth stage, which takes the ship from a high suborbital trajectory to Kerbin escape or just before. (Aerospikes feel less cheap now that the nukes are out. Still considering switching them for T45s and just living with the lower performance.) When I get attachment privileges, I can post the .craft file if you like! Dropping the first set of really big liquid boosters without hitting them and exploding does take a bit of practice, though.

... double post, sorry...

The pad weight of the full stack is 1295 tons. It doesn't quite get the lander into transfer orbit; I have to burn a little bit of the descent stage's fuel to get to Duna. It's turning out a pretty capable ship - I took a Kerbin -> Eve -> Jool -> Kerbin trip with it last night, but didn't think I had enough fuel left to land on anything.

I went to Duna today! Made a powered landing, left behind a descent stage, and returned safely to Kerbin. My lander weighs 140 tons fueled. Nothing like that feeling when, after many explosions, you finally touch down, switch off your engines, and everything goes quiet.