Ninety-Three

Oh let me tell you about the limit. This is how you get to the limit. The principle is that all the engines fire from the start. Fuel lines make sure the outside tanks empty first, and every couple seconds you stage out, ditching a layer of empty tanks. In this way, you can achieve 30 seconds of thrust while maintaining the TWR of a Mainsail carrying only 4 tons of fuel. If you have more time to kill in the VAB, you could even switch the fuel containers to 2 ton affairs, making it into twice as many, slightly more efficient stages. (Tip when flying this monster: Stage out just before a layer runs out of fuel. If you wait til after, that layer spontaneously converts into dead weight, which puts all sorts of unpleasant stresses on the ship).

I've always found that just hammering F1 does a decent job for anything short of colliding with the ground at Mach N.

I imagine Pursuedtank broke off the engine by getting the ship extremely close to the surface, and then rotating it. The engine smashes into the ground powered by ship rotation rather than gravity, and breaks off.

Any chance the thing can be launched in two pieces? It weighs so much that docking ports don't have the strength to support side-mounted engines, and when you try to thrust from the bottom, it gets a little... bendy.

I have a six engine plane (one fuel tank, two fuselages, three wheels, no extra weight) which parachutes safely and is theoretically flyable, but you have to fight the controls every step of the way. I made it to the KSC2, but I'm fed up with the thing, so it's shelved. The new project involves Mainsails.

Disclaimer: I don't actually know what I'm talking about, this is just me repeating something I read out of a guide which seems to work. The trick is to keep your center of lift slightly behind your center of mass. That, and flying with sensitive controls (Capslock).

Sure I can.

I gave my ship another run, came in a little slower this time (5:48), but with all my bits still attached. I think I'm going to try a six-engine confgiuration with splitters and see how that works out.

Asdier, here's the file for my parachute-based lander. Everything works off action groups. I keep tweaking it and trying to make it faster, but it's got three engines on one fuel tank and two empty fuselages, so there's not much more speed to get out of it. Also, because I don't understand how planes work, some flights when I take it back to KSC1, it's going 240 m/s, sometimes 250. Does anyone know what might account for 10 m/s change? I know it's not fuel, but that's all I can control for.

The wings tore off, but it could still drive around. Given that the challenge didn't specify a perfect landing, and that Jeb could walk away from it, I feel like it should count. Anyway, I'm trying the flight again with less fuel to see if a lighter plane does it much faster, I should have a proper landing shortly.

I did an all-stock run, landing at both runways, in 5:43. http://imgur.com/a/1BkV3 The craft, full mision pictures in the album above. I am really bad with planes, I've never done more than spin out the stock planes and build some ion gliders. So my plane design cribbed pretty heavily from the Aeris 3A. I knew I couldn't land a plane to save my life, so I made a little addition that, ended up saving a lot of time. Rather than lining myself up with the runway and braking, I just coast over the runway and deploy some parachutes. At under 60 m/s, they shouldn't tear anything off, and they'll instantly kill all speed, leaving the plane to float to the runway. My run wasted about ten seconds taking screenshots at the KSC2, and came back with something like 60% fuel, so emptying out some of that fuel for weight reasons ahead of time could make it faster.

Thank you, Alistone, putting it in terms of gravity drag vs realistic TWRs helped me understand it. I did a test with this... slightly overpowered launcher: I found that the "Straight up" method left me with slightly more fuel, but that was moving a 25 ton ship with four non-nuclear rockets. I can see how attempting that burn with a single interplanetary nuke engine would be a lot worse.

Just recently, I realized that I'd been doing my interplanetary flights the same way I do my Munar ones: Fly up, establish a 100 km orbit, burn at PE until your AP is where you want it (out of the SOI, or intersecting the Mun, depending on where I'm going). It occurs to me that if I'm going to say, Duna, it seems more efficient to just burn straight up until my trajectory is leaving Kerbin's SOI, without bothering to orbit first. However, I don't actually understand any of the principles behind efficient rocketry (I've sort of just been cribbing from youtube videos and memorizing the practices), so I thought I'd ask the forums: Is that the right way to go about it?

I don't know nearly enough about the spaceplane part of KSP to be sure about this, but could the sorcery that powers infinigliders be used to cheaply bring a ship up to a decent altitude?

I think I've found the optimal strategy. Mainsails have the highest TWR. Because only about 0.1% (actual figure) of the mass isn't an engine-fuel component, when we stage out on this thing, TWR stays constant. So this is a craft that, as long as it has stages to spare, maintains a constant TWR of Mainsail/10 tons. A more patient engineer than I could switch in smaller fuel tanks and more stages, probably shaving off an extra second or two. Nineteen seconds. I missed a great shot of the lower stage on fire, so this is all I have. Parachuting safely to the ground. Edit: For the record, the name of the ship was the Ultrasparagus.

Take a look at my submission. You can't have a kiloton of dead weight without either a lot of fuel, or a supercomputer to handle the lag. Having fuel left over lets you do some pretty extreme things.

Clearly I think differently than you, because I hadn't even been planning to leave the atmosphere, let alone get far from Kerbin. In light of the updated rules, I changed my plans slightly, but found they still worked fine. You seem to be maximizing speed. I assumed that the atmosphere would bleed my speed down to terminal regardless of how fast I came in, so I set out to maximize mass. Yeah, it's pretty silly. For the first minute and a half (before the first stage was jettisoned), time was dilated by a factor of four or five due to lag. But it was worth it. I burned straight up, and here I am taking a jaunt out of the atmosphere to satisfy the rules. I forgot to get them in shot, but I've got some RCS tanks and a million side-mounted thrusters that I used to get myself pointing down while in space. I waited until I was fairly close to ground to start burning, figuring it'd just waste fuel to start sooner. And here I am about to crash. The screenshot is further from ground than I'd have liked, so I'll deduct a bit from my fuel to account for the fact that it should have gotten a little lower. Calculating the mass: 19 engines * 6 t/engines = 114 t 4*18+5 dry fuel tanks * 2 t/tank = 154 t 80000 liquid fuel and corresponding oxidizer * (1/90) t/fuel&oxidizer = 888.9 t 128 RV-105 RCS units * 0.05 t/RCS = 6.4 t 2546 monopropellant * (1/250) t/monopropellant = 10.2 t 4 large dry RCS fuel tanks * 0.4 t/tank = 1.6 t Command Pod Mk 1 + SAS = 0.9 t Total: 1176 t Ek = 0.5*1,176,000*(218.3^2) = 28.02 GJ Boom.

I thought I was done with this challenge, but a little voice at the back of my head wanted to to do it again without crashing, and seeing someone get a higher score than me spurred me to action. I built it in the plane hanger for the use of plane symmetry, and didn't know how to move that to the rocket hanger, so I had to build a rocket in the spaceplane hanger, using 2d symmetry only. That was a fun challenge. Check out the rover. Eighteen wings of 15 panels each, powering a whopping fourteen ion engines. The rover assembly probably weighs in around 16 tons. Those are asparagus-staged jumbo engines providing the majority of my thrust, and they prove remarkably effective. Check out what I put into orbit! I was amazed at how well that worked. Once I had it in orbit, it was time to bring up the crew. Two ships got within a kilometer and EVAed four more pilots to me. We're off to Minmus. I'm still amazed that this balances so easily. I tip it down and I'm off. Around 150 m/s I tilt sideways again. Hopes for a recovery are dashed when my controllable area is reduced to a cockpit with a wing attached. So I try again. This time I put on SAS, just to see if it helps, and start rolling. After a while, something strange happens. I looked at my front wheels and saw them doing that, sitll under SAS control. Pretty quickly I realized it was perfect: the rover can't start bumping around if it's only on two wheels. As I kept going, the SAS drifted up, so every now and then I'd disable SAS for a moment to let it drift back down. Eventually I figured out why: The curvature of Minmus was making me rotate relative to where I'd been when I set the SAS. Science! I accidentally let the SAS drift a little too high, maybe ten degrees, and when I tried to let it drift back down, it stayed exactly where it was. Then I slowly took off. Apparently I'd gotten enough speed. I leveled out, and continued to rise. Orbit any moment now. For some reason the camera does a perspective-switchy thing when you achieve orbit. Handy indicator. I clear the hills and it's back to Kerbin. Somehow I always end up in that area. Reentry shots are still pretty. It starts spinning when it gets low. I realize that those parachutes could have been better placed, and start praying that they're not going to tear off when they deploy. They made it. Corfrod, Neilfrid, Shelwig, Gregsy (not pictured) and Will (not pictured) Kerman have returned, each convinced they were the one piloting the return in their own cockpits.

20 of those panels feed an ion, and there's 15 per wing. The only magic is how efficient the OX-STAT tiny panels are. And the bloody lag that 300 of them creates. I only discovered that technique tonight, during a run of a new rover I'm about to post. God does it make things easy. Depends how you count. That was my first try with that model of rover, I thought I was sunk when it tilted and crashed, but tried to stabilize for the heck of it. Shocked to find it worked. Using an earlier rover with wheels closer together, and not knowing the SAS trick, I tilted to my death four times before redesigning.

The rover has twelve engines, and weighs almost exactly ten tons. Theoretically, it also has exactly enough solar panels to power all those engines. I say theoretically because my math says exactly but I was able to run it at full throttle without draining the battery even when panels were only providing 94% power. Misc lessons learned: On my decently powerful machine, 320 OX-STATs generated a noticeable but manageable amount of lag, and it was pretty much just dropped frames, rather than time dilation. While I was still in thin atmosphere, I noticed that the SAS was doing a surprisingly good job of keeping me level, and even generating an unwanted amount of lift (luckily I shut it down before overshooting the continent). I imagine that if I hadn't been missing two wings, and had any idea what I was doing when it came to planes, the plane made entirely of control surfaces could have been taken on a glided landing. I had some pretty severe problems with left-right unstable rovers before switching to the design you see with wheels two wing lengths away from the body. I'm guessing the bouncing I encountered could be helped by putting more distance between the front and back wheels (and maybe evening out the centre of thrust). Incidentally: How in god's name did you keep that stick of a rover stable? I was having a nailbiting time with my giant slab, I can't imagine doing this with something that snaps off all its solar panels the instant it leans left.

Continuing my rather picture-dense accounting of this challenge in a second post. Flying ion engines is both fast and exciting. Remind me to never, ever make my probes Ion based. Have you noticed that my plane doesn't have any re-entry mechanisms? I sort of missed the part of the contest where you're supposed to return your Kerbal alive, until I was in my Minmus exit orbit. Oh dear. Still, let's come in for a landing. Re entry shots are pretty. Pretty quickly I start spinning out of control at 60 revolutions per minute. The re-entry on my xenon tanks looks pretty though! The ground's getting awfully close and flooring the A key isn't stopping my spin. I don't think this plane is going to land. Luckily, I remember the wording of the challenge. Get the Kerbal back to Kerbin. The ship is disposable! This plan is seeming a bit weak. OH MY GOD HE BOUNCED. Ladies and Gentleman: Neilfrid "Made of Rubber" Kerman. How do I get home?

Well I've done it! Sort of. I've documented my journey below. It turns out that using a slightly lag-inducing number of OX-STATs gives plenty of TWR, despite my earlier worries. My rover landed on Minmus. I set it down at about 2 m/s and was surprised to find that stable. Landing's the tricky part, deploying is just a matter of nudging the SAS controls. Once I got the rover on its wheels, I zoomed out to identify a long stretch of Minmus to drive along, and fired up the Ions. When you get going fast, your rover starts moving around a bit more than you'd like. If you were thinking "Oh my, that seems like quite a bit of air your wheels are getting", yes. A bit too much air. About a second after that screenshot, my rover hit the ground a bit sideways, snapped off part of a wing, and threw itself into the air spinning madly. Unfortunately I didn't get any screenshots of the chaos, but when I had more or less stabilized, this is where I was. Still pilotable, though it now drifts slightly left. So I pointed myself perfectly at the horizon and soldiered on. Hey, my engines have only been providing horizontal thrust, it still counts! Suddenly my camera changes orientation and I go to the map screen to check. We have an orbit! We're going to clear those cliffs, right? Phew. From there I'm headed cleanly away from Minmus. Now it's just the tedious matter of flying a fixed-panel ion plane with a wonky center of gravity.

I've been experimenting with this, and the theory behind achieving orbit at an altitude of 0 is certainly sound. Currently all my rovers have been flying out of control around 80 m/s (I need to make them wider, it seems), but Minmus's massive perfectly flat stretches provide plenty of space to accelerate, and Minmus friction on rover wheels is negligible: in several seconds, at 50 m/s, my speed didn't decrease at all. I'm a little worried about getting a decent TWR. Even on the quarter-of-the-planet flat runway you get from Minmus, you have to have an at least reasonable TWR to avoid running out room on your quest for 242.61 m/s. With an infnitely powerful computer I'm sure it could be done, but without the ability to plaster a thousand OX-STATs on one rover, some care has to be taken. Alternatively, if you bend your interpretation of the rules, you could get enough Ion power to hover, and then just have one engine push you forward until you eventually hit escape velocity sideways, but that seems like cheating, so I'm going to keep trying for the fair way.