GoSlash27

That must be what it is. I'm running 25.0.642. All of my old gliders were broken due to the gear. I balance beamed them and they weigh half a ton each! That's why my latest entry uses no landing gear, just angled wing stubs to serve as skids. I'm so close to orbit now, I may as well just tough it out. Best, -Slashy

Aand ol' Slashy is officially on the board. 37,082M at 1,858M/sec. No control surfaces at all and +10% no battery bonus. I think I'm gonna make orbit! Spirit of Kerbin City .craft Flight profile: Launch eastbound at dawn Pitch up until best speed is achieved, then engage SAS. At 27 Km altitude, pitch to maintain 5-10 m/sec climb At 20* pitch, maintain 20* pitch until fuel exhausted. -Slashy

MabDeno, I got the leaderboard updated. Are you still running .24? Those landing gear pods are worth like a ton and a half with .25 update. Best, -Slashy

Laie, You definitely want enough wing to clear the wall, but any more than that is a liability once you get past it because it's dead weight. MabDeno, Cingratulations! You just broke the 1K barrier! I'll get the leaderboard updated in a bit, gotta head out to work. Best, -Slashy

Rocketeer, Actually, the wings do not have the same drag. They have unique induced drag numbers as well as parasitic drag and the induced drag is a quadratic function of speed. The swept wing was clearly the way to go in .24, but... This is complicated by the new offerings from the .25 update, which contains some wings that look very promising on paper (hint, hint)... The Kollier trophy challenge is almost completely an engineering exercise. All the exciting stuff happens before the plane is placed on the runway, and the actual flying is about as interesting as watching paint dry. Right now, the competition is just to be the highest and fastest. But speaking from experience, it's not a linear slog to orbit. The first 10 km takes forever with seemingly no gain other than altitude. Then 25 km happens in the blink of an eye and you're going so quick you have stability issues. 25-30 KM is like a wall, where you are seemingly unable to gain any more speed or altitude. If you get north of 35 km, you're almost assured orbital velocity *if* you have enough fuel and daylight left. Best, -Slashy

Labhouse, So we're talkin' an exact duplicate of the launcher complete with fuel and all? Basically a LV with payload fraction equal to or exceeding 50%? Crazily, I think I know how to pull this off without glitch exploiting. For sure I can do it *with* glitch exploiting. Best, -Slashy

(edit) Nevermind. After re-reading the rules, I spotted something illegal about my proposed entry; "no part clipping". I was gonna take a kraken drive infiniglider and have this challenge done in no time -Slashy

Viragos, Any mod which does not alter the performance of the stock parts or physics would be fair game. So long as your craft *could* be constructed and flown in a 100% stock installation with 100% stock parts and get the same result, you're good to go. Best, -Slashy

Something that's so self-evident that I'd never really thought much about it: Lift/drag is equal to the inverse of t/w in cruising flight. This is because in level flight where you're not accelerating, lift equals weight and drag equals thrust. It should be a fairly straightforward task to fly in various regimes and empirically determine the lift- to- drag for various components and see if the math lines up. Best, -Slashy

I'm trying to come up with a linear "figure of merit" that scores all the engines in KSP for t/w, efficiency, and price. Clearly, Isp and price are easy to pin down, since they are linear to relative worth. All things being equal, an engine that does the same thing for half the price is twice as good. Likewise, all else being equal, doubling the Isp doubles the worth of an engine. But this is not the case with t/w ratio. Doubling the t/w of an engine won't make it twice as good. Depending on where it was to begin with, a doubling could have a much more dramatic effect or no noticeable gain at all in the performance of the vehicle. Basically, doubling the t/w is saying I'm carrying half the mass of engine for the amount of thrust, leaving more payload and fuel, but that won't be twice as much. For it to be truly linear and scalable, we'd have to take a natural log of the (engine mass+full fuel tanks+payload)/(engine mass+empty fuel tanks+payload) The question is where to set fuel vs. payload and where to set the sum total of both for an apples-to-apples comparison. Would setting the fuel+tanks in a stage equal to payload at 1G generate a useful ballpark datum for Kerbin launches? Open to suggestions, -Slashy

If that were the case, they'd be bluish, not green. Best, -Slashy

All due respect, but I definitely can. with a 4k screen, you can't even see that the image you're looking at was rendered with pixels. You can't see the pixels in a 1080p display, but you can still see the loss of detail that results from rendering. You can't see that loss of detail on a 4k screen. It doesn't seem like a big deal until you see it in person. Best, -Slashy

I noticed that about some of the new control surfaces; some of them are ridiculously drag-free... at least on paper. I haven't worked out a test rig yet to verify the behavior in-game. Best, -Slashy

It's not. At least, not without glitch exploiting. I've gotten closer to Eve orbit than anyone using ion gliders, and I wasn't close. Heck, we haven't made an Ion SSTO that works on Kerbin yet, let alone Eve. Gyroplanes simply can't match the altitude capability of ion gliders, so they would fare worse. Best, -Slashy

I started on the demo version. I pretty much followed the NASA progression for spaceflight. I didn't have a lot of failures because I went after the math first. Best, -Slashy

What, exactly, do you mean by "no cheating"? -Slashy

I'm thinkin' your booster wasn't optimized to your payload, so the effect of doubling the payload was heightened. It doesn't take a 92 ton vehicle to put 1 ton in orbit, even SSTO. For example, you could do that job with a single aerospike and the total vehicle mass would be about 11.3 tons. Building the same lifter for a 2 ton payload would be about 16 tons. In this case the 1 ton increase in payload created a 4 1/2 ton increase in total mass. And that's just one stage. The more stages you use, the more the effect is exaggerated. Best, -Slashy

Also, the KrakBadger 2.5. http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/KrakBadger A kraken drive infiniglider that uses no fuel. I took off from KSC, transited to Eve, landed on Eve... and that's when things began to get hairy Landing near my Eve Express base caused a severe lag that gummed up my action group to trigger my kraken drive, forcing Jeb to activate and deactivate it manually using a monkey wrench. All hopes of flying a precision return were out. Limped back into Eve orbit and got a rendezvous home. Narrowly avoided splattering Jeb on the Mun and got an ugly reentry on Kerbin with no harm done, but I was a long way from home. I infiniglided back to KSC and landed on the runway. Close call, but I made it! That should be worth an advanced pilot precision award and expeditionary astrokerbal distinction (Eve). -Slashy

Please review this one for my first "gatecrasher" award. http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/ULS%202_0 It's called the Utility Launch System 2.0. Advanced pilot precision award and utilitarial distinction for docking 15 tonnes of payload with an SSTO that only weighs 13 tonnes empty. "HTOL is *so* 2013!" Best, -Slashy

It's gonna work out to roughly 2^(N-1) X 2Mp where N is the number of staging events and Mp is the mass of your payload. If you look at the 2Mp part, then yeah it's linear. But the 2^(N-1) part makes it exponential. The upshot is that saving a little mass at the pointy end saves a lot of mass at the hot end, so it's in your best interest to design each stage to be as light and efficient as you can make it. Best, -Slashy

Kraken attack. That's a bummer. Best, -Slashy

RoosterWing, Why would they be unable to stack due to docking ports? Can you share a pic of the landers? Best, -Slashy

Jouni, It is, indeed exponential (though I can understand why you'd think it wasn't). Doubling the payload of a stage will double the mass of the stage to generate the same DV. And while I'm saying here what you just said, this is an exponential progression back down the ship. Grossly simplifying the math to illustrate... You have a 1 ton package to deliver to orbit from the surface of a moon. That means your ascent stage is 2 tons, your descent stage is 4 tons, your transfer stage is 8 tons, your injection stage is 16 tons, your transstage is 32 tons, and your booster sitting on the pad is 64 tons. If you double the mass of that payload, then you've doubled your launch vehicle to 128 tons. So 1 kg increase in the mass of your payload has cost you 128 kg on the pad. Keeping things small, light, and efficient pays huge dividends back up the chain. Best, -Slashy

This is an odd objection IMO. What if he'd been doing this all along in order to donate rides to "make a wish foundation" once the venture was up & running? Your attitude seems to be that "putting rich folks in space for thrills" is somehow immoral; like rich folks don't deserve to go to space merely because they can afford the trip. This is how all the transportation technology we have today started out. Automobiles were playthings for the rich in the beginning. Rail travel, transoceanic passenger liners, commercial air travel... same thing. Electricity, telephones, home PCs, the internet, cell phones, and flat screens were all once status symbols for the rich. Eventually the advancements in technology (which the rich folks paid for) and competition (for the rich folks' money) got us to the point where everyone has access to this technology. So yeah, I write off this crash as a necessary evil in the pursuit of space. Just because they weren't pursuing it in a way you approve of doesn't mean they weren't pursuing it. Best, -Slashy

Numerobis, Yeah, I mean on the pad. But my point isn't that you can score a few seconds of Isp by building a taller rocket, but rather that your rocket spends so little time in the "atmospheric" regime that you may as well not even bother worrying about Isp (atm) figures in your calculations, at least for vertical lifters. Just do the math for the whole launch assuming vacuum numbers, and you'll be pretty much dead- on. Prior to this, I was designing my lifters on the assumption that everything short of orbital injection was atmospheric figures and the injection was mid-way between atm and vac. In truth, the boost phase prior to gravity turn is midway between atm and vac, and all of the rest of the lift is vacuum. Best, -Slashy