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FTL ... build ship with X parts, launch into orbit, then fight with ship as in FTL where layout corresponds approximately to the X parts used. Initial mass of crew pod and weapons determines overall cost of launch, # of crew, and the weapons themselves. I'm sure there's other things to add to this.

Oh right, here are the categories: -- No Need to Improve: Land your rocket on Duna exactly as it was when it left Kerbin, launchclamps excluded, (applies once all transfer and landing stages are removed) - +800 I'm not sure if I understand that one. Does it imply SSTO? Or does it imply not using the payload rocket for any purpose along the way? If the latter than I did that one otherwise obviously not. -- Moar Struts? No.: Have no struts leading from the launch, transfer and landing stage to the payload - My only struts were from launch to launch. -- Nuclear Non-Proliferation: No nuclear engines or RTGs - +50 -- Limited Size: Use only 1m parts (or less) - +200 -- Landing on Engines: Drop your return rocket onto Duna by landing on at least one engine - +200 (Does not stack with No Need to Improve) (though doesn't stack if I got first one) -- Homecoming: Return to Kerbin by landing at KSC - +100 -- Slowing Down the Hard Way: Complete the challenge without making use of a single parachute during any stage of the challenge - +500 ------------------------------- So the ones you didn't mention are struts, land on engines, and no improve (if applicable).

Here is my entry, the design of the original craft inspired by Ravenchant's (rocko+small tank+light legs): Original craft mass was at 100% = 6053 kg. I did quicksave and reload several times to aim the landing back at KSC as I have no idea how to do that otherwise.

tavert I copied your idea of using the super light top stage but otherwise tried to extend the record: I may also have to copy the all half-orange idea if that's truly the fix. A failed launch isn't normally a big deal, but it takes several minutes to go from VAB to launch to T+ 5s. Then when I click a part back in VAB and move the mouse, the laggy mouse event handler decides retroactively that I clicked an entire assembly, but after I put it back (30 seconds later of trying to get it to snap), it's like by the way everything's rotated and your struts don't connect anymore (undo doesn't help and takes about the same 30 seconds...). I may give up on this one...

tavert I don't understand those calculations but it's bed time so maybe tomorrow I'll figure it out..but the part about ~200 m/s difference is interesting.

If enough other people do, sure. It goes hand-in-hand with optimal ascent, and leads to the best overall craft I guess.

I too have an entry for a light-ish deltaV craft: The half-high orbit was me being lazy and not wanting to figure out how to get 0.25 TWR into standard orbit, so I just climbed entirely too high while I had the thrust to buy time to circularize. I forgot about min TWR but the one screenshot shows it pretty close to it since not much fuel was used by the nuke post-rocko-burnout. The keen observer of our entries sees that we burned far over 4500m/s to acheive orbit (due both to horrible takeoff TWR and usage of nuke at low Isp), and so the deltaV figures given are sort of padded by using lots of fuel to maintain a hover more or less. edit: Is it better to lift the nuke with more tiny rockos for a couple thousand feet? I know in general one wants to use all engines where possible but the nuke becomes far more efficient pretty quickly so intuitively it seems like if one waits a bit then activates it...I mean does 0.3 mass of rocko really lower the dV beyond what is saved by not burning through nuke fuel for the first minute?

Oh right I forgot about drop tank method....so my math is wrong for max possible...what's your delta V in this setup?

I prefer brute force myself, so weighing in at just under Jool: I have a nitpick with the staging award, because for max deltaV per stage you would want serial/onion staging. The award should perhaps be "fancy staging" for users of asparagus. Just messing around in the editor it looks like a nuke can break 15k but for overall part count reasons I didn't go all out. I only used 4 stages too, so 15k+15k+15k serial then 2 for liftoff, or as suggested, 1 for liftoff (absolutely ridiculous number of mainsails needed....) you could do 4*15k or more in nuke stages. Max deltaV could approach 70k but my computer seems happy with 23-24k for now. edit: Cool design tavert...super small for such deltaV!

By the way minor tip: if you rebind it to a multi-key combo e.g. shift-backspace instead of backspace, you can avoid canceling a perfectly good launch. Now if only there was some auto-turn-on-staging-again functionality for when I'm about to land...

How do you decide proper fuel size tank? edit: And I agree, max fraction depends on the payload size.

There's definitely some upper limit (well obviously it's not infinite). One could set up a recursive program or equation if so inclined to figure out how much each additional pair of best-sized rocko stage adds to the overall solution's mass, and then map this equation onto a range of payloads and take the max. Maybe I'll work on that when I'm lucid.

The "(nvm)" was me making no sense due to a mistake on my spreadsheet that I caught. I disagree about fuel costs being low because one carries more fuel than engine mass in a launch intended to reach orbit+. edit: nvm again...I need to sleep more.

Hmm you're right...now that I look at it, the aero doesn't surpass the rocko until ~1750 dV, by which point you are at a height where the aero has no chance. However (!!) the aero generally uses less fuel, falling the tinniest bit behind in full vacuum at higher dVs, but overall, not having attempted the calculation, I suspect the aero uses less total fuel to reach orbit, using whatever stages are optimal to do so. This is important because in reality (in game reality, or real life I guess), you attach a parachute to the engine and then you don't have to buy it again. So considering refueling, even if you want to strictly go by payload fraction, then the mass over repeated missions is minimized by aeros because the equation changes from payload/(total mass) = payload/(fuel+engines+etc) to payload/(fuel*#(missions)+engines+etc). I would argue that using less fuel *is* using less mass. Implicitly, it costs less over time which to me is the real goal, i.e. if person X builds rockets according to this challenge and person Y builds rockets with aeros, person Y will accomplish more with equal resources. edit: (nvm)

numerobis when you say your deltaV and TWR with aero such and such ... are you comparing at sea level pressures, vacuum, both? Because if they seem comparable with vacuum stats then in truth aeros are better overall.

But why would they make it 9.82?! This throws off everything. I don't even know which way is up. Launch angle = -pi/2 from now on.

Detached unparachuted booster DIRECTLY UPWARDS after re-entry. Did not think it would actually strike the command pod and vaporize Jeb. There's always that 0.01% not-directly-upwards type thing because it's not like I can aim perfectly. Sorry Jeb.

Thanks I've got most of it now, but I'm ignoring centripetal and Coriolis for the time being. By the way, I wasted a lot of time figuring out why my algorithm got progressively worse over increasing iterations and generally performing horribly until I realized that I was returning the minimum instead of maximum performer at the end. (WHY DOES MAX HEIGHT ARE ZERO?!?) True story... edit: Found another problem...incorrect fuel calculation was causing excessive fuel burn. I was using altitude-dependent real g instead of 9.81...survival of the fittest now produces nearly perfect throttle genes. Now that this garbage works, I'm going to try to evolve genes for a neural net to fly it instead of directly encoding throttle. Hopefully this results in a brain that can fly any craft instead of the specifically-solved-for one

I'm working on the exact same thing. Currently in the testing phase for 1d motion to confirm that my algorithm comes up with terminal velocity ascent.

Which is why you should *always* use such panels, only augmenting with extendable ones where necessary. No reason to risk failing a mission depending on whether you time warp your 4k energy per second sputnik probe because you forgot to press 1, or because you forgot to press it a second time when you descended into Eve.

My preferred method for solving this would be random search, either by explicitly doing something like random walk or using a genetic algorithm. The math seems a bit complex to "solve" but a computer flying millions of variations of the path per second can probably come up with a near-optimal solution fairly quickly...so if we can live with knowing what gets us 100.0002% of best fuel usage, I believe the problem is simple enough. If I can find enough info on the physics within KSP I shall make one today (seems to be the hardest part).

I suggest a slightly different approach...you see in theory you just would use 100% payload fraction and not bother with engines to be perfectly efficient, but of course this is not possible (pending teleportation...), so it's kind of odd to use payload fraction as the independent variable. The payload fraction is actually set/capped for a payload by available engine and fuel tank designs. What you are REALLY using for input parameters to your optimal rocket building function is payload, TWR, and deltaV--i.e. the rocket has to carry so much, so fast, and so far ("so fast" because "actual v" is not deltaV when you lose 100% of it at TWR 1 in a hover over Kerbin--farness depends on fastness). Certain engines are better at certain deltaV and TWR combinations for various payloads, so given a payload, there is some proper engine choice to accomplish the mission, and you get whatever payload fraction you get. If you want a higher fraction, you're going to have to invent a better engine or a lighter fuel tank. edit: Stand by for a mod from me to figure engines and fuel given a mass to lift... edit: Done! But spaceport is down

Are you building the first Reaper (Mass Effect)?

Hold down windows key and press num+. Then press crtl+alt+i. Do it.

Make sure they don't activate on your takeoff stage ....................... Similarly, make sure your launch support things DO activate on your takeoff stage ...................... Similarly, make sure your engines ALSO activate when the tower detaches .............. Otherwise...spend 4 hours designing ultimate rocket of perfection....press spacebar and blows up on the launchpad. I mean, really??