Laie

Yup, same here. Well, not quite, I do bother sometimes, but for me it's unintuitive and hard to plan. A key aspect is that you don't simply gain or lose speed (strictly speaking you don't: if you just fly past Kerbin, your speed as you leave the SOI will be just the same as wen you came in), but that your trajectory gets bent by a few degrees (which can result in quite a noticeable difference after SOI transition). For gravity assists to work, it's not enough to do a close fly-by, but you have to come in at the right angle as well. My usual screenshot: That's two maneuvers ultimately leading to Duna, one of them using a munar assist for ~90m/s gain. See how I'm approaching the Mun's trajectory at nearly a 90° angle, but fly off at about 60°? Although I can't really explain the how or why, I know that this is what makes the magic happen. Flying out "more parallel" than you came in is what speeds you up.... I think. Did I mention that I haven't entirely mastered the topic myself? On interplanetary trajectories the angles can be much less conspicuous. For your Kerbin encounter (which I can't really see in the screenhot), it seems as if you're coming at Kerbin in a somewhat hohmann-ly fashion, flying nearly parallel at the time of encounter. That's why you lose no matter which side you pass it on.Try to make it so that you approach it at a small angle, that is, your PE is a little inside Kerbin's trajectory and you encounter it on the way out.

Wing and cockpit are SXT. The concept is stolen from @sevenperforce; for what flying wings are capable of in stock aero, see Cupcake's excellent video. Alas, I have to rely on the MJ clicky-thingy for control... I could confirm that even this large and heavy beast can flare and come to a full stop on a dime, but I would have to plan my approach from like 10 miles out. However... after having had a look at the islands, with two of them I wonder if I can even stand there with brakes engaged, or if i would simply slip off.

Today, I went off a cliff:

Yes, but. You're starting small and are content if you can get to orbit and back. Which already is a bit of work: Be honest, designing your plane was a lot more effort than coming up with a rocket to serve the same purpose. Flying it also is more difficult than a rocket & ballistic return vehicle. A lot of people only get into spaceplanes once they have a need to regularly ship large and heavy payloads and/or want to get to faraway destinations right away, which exposes them to a lot of problems, many of which you're not having yet, all at the same time. That is indeed a steep hill to climb.

Half of the deal is knowing what a good assist looks like -- schematics showing a 180° U-turn are misleading, like @5thHorseman it didn't click for me until I got an accidental assist. Before, that, I've tried it from a wrong angle (heh), getting me nowhere. Example of a munar assist saving ~90m/s: In order to set it up, I like to use a "marker" probe that has an ordinary direct burn for a maneuver. My trajectory, post- assist, has to run very nearly parallel to that of the probe; this allows me to do most of the tweaking without constantly zooming and and out on the map. For the benefit of @MisterKerman: that's a totally different problem. If you start from a munar orbit, going through a low Kerbin PE is indeed the way to go, that's true. But it has nothing to do with gravity assists.

Yeah, alright. But I take this as an opportunity... folks, pay attention where exactly you pick up your software. Recompiling free software with some barbs and/or bundling it with malware is a business model. My GF once got some unwanted functionality when she DL'ed stuff from project-name.com (rather than .org). The website looked good and everything, I can't blame her, really. The larger projects (like e.g. Firefox) have resources to fight these copycats, but not everyone does.

That's a neat design! I like the gap in the center stack (and how you follow up with an intake -- for drag reduction I presume?). But, in all honesty, I wonder if it's really worthwhile: personally I'm under the impression that a service or cargo bay is mass well spent. Yup, same here

Well, that's an outgrowth of "biggest vessel wins"... Yup, though that's no longer a "vessel" but a system. It's what reminded me of the Laythe Capitalism challenge which was fun to do but a PITA to score. -- I've meanwhile done this with a single vessel, a large plane similar to what I posted above. The most difficult part, by far, was takeoff on Laythe under a full load. Even after carefully picking as level a track as I could find, I had to get off the ground at ~80m/s or it would break up -- no runway, see? I probably shouldn't complain, 80m/s is quite a ludicrous speed for going cross-country... For testing purposes: if your vessel can break the sound barrier on Kerbin with a full ore load, it can make space on Laythe (fuel permitting, of course). A direct Laythe->Kerbin Transfer cost me about 1100m/s. However, I had to use my engines for a 500m/s slowdown on Kerbin approach in order to survive the aerobraking.

On first impulse, I'd say "weak springs, strong damper". Though from what you write I guess you already tried that.

So, for what it's worth, here is an excellent savegame for this challenge (and presumably others as well): 12% ore density on Laythe, at least on the spot where I'm landed above, also on the small island to the east. On top of that, concentration is 14% on the runway, which makes for easy testing of refinery designs. Savegame is fast-forwarded to the launch window in Year 3.

I'm afraid you'll be disappointed no matter what. As Foxster said, the atmo is soup, the drag is horrible. You won't get very far (or fast) until fuel runs out. If you're patient, you can glide a fair bit -- but then, average speed will be not all that much faster than a rover.

First off, you can periapsis-kick however often you like (or need to) in arbitrarily small increments, until AP reaches the edge of the SOI. But then, for a halfways dV-efficient transfer your last kick has to provide for all the remaining dV, all in one kick. That's where I see a problem. If that burn is going to last longer than a couple of minutes, you'll have a problem , both with planning and with needing more (possibly much more) dV than with a standard maneuver. I haven't checked, but 1400m/s doesn't leave much headroom, does it? Would it even suffice if you could do an instantaneous burn?

I don't believe in the "making room" theory, if only because it's bound to become a PITA when judging challenges. AFAICT, the no clipping rule serves two purposes: help with making a craft understandable, so one can conceivably rebuild it from pictures. if you bring lots of stuff you vessel has to be as tall or wide as the game says it needs to be. Don't put five items in one place than brag how it fits into a small cargo bay. The easiest rules to follow are those imposed by the game, however, even Ziv himself hasn't be too poophole about this (EDIT: another example of the profanity filter not helping at all). Structural parts could be pretty much clipped at leisure. In the case at hand, I'd consider the radial engine mount to be such a piece. KSP engines typically consist of little more than the bell itself, anything beyond has to be structural.

Ok, so I'm being a pest. I can't help it. I love the premise of this challenge, but don't think the scoring system is really up to it. But, let me start with what I have. SSTOs capable of going to Laythe and back with ISRU aren't particularly hard. It's just a question of scaling it up a little to carry substantial payload: The above vessel can take off from Kerbin and proceed to Laythe. I haven't tested the return trip yet. However: being able to SSTO without oxidizer, this one has what I consider to be excessive TWR in the nuclear department. At least for interplanetary purposes. It could, at least in principle, move much more than one cargo bay full of payload between the destinations: No docking ports yet, but you get the idea. It's supposed to aerobrake on either end of the trip, the ore tanks will be protected from the worst heat by the wings. Outrigger tanks remain in space, the vessel shuttles five times on either end of the trip. But once you take it so far, one has to wonder why the plane is supposed to go there and back again. After all, all you need to do is move some ore, which is easy: This can shuttle between Kerbin and Laythe; you could probably join at least seven and start several bundles per launch window. It then becomes a question of how many you can fill on any given year. I also wonder how it's supposed to put into any weight class. By the way, have you ever heard of Laythe Capitalism?

I'm in the middle of craft design and notice that there's a point I'd like to have sorted out... will ISRU be okay? I mean, of course I'll have to mine for ore on Laythe, but can I bring a converter and make fuel for the return trip? If so, can I make (and use) oxidizer as well?