GoSlash27

Zarakon, Simply having horizontal control surfaces is enough to give you some infiniglide advantage, whether they are locked or not. It is as you said; drag becomes thrust whenever the AoA is greater than zero. Also FWIW it's cheaper in terms of real-estate to carry solar panels instead of batteries for the flight duration required to reach Kerbin orbit. Best, -Slashy

My first entry: 1,550M/sec @35,034 M altitude. It's got minimal control surfaces and 2 xenon canister drop tanks. 201 parts (mostly solar panels), exact mass unavailable, but extremely small. No RCS on this aircraft, so DV for ions is 100%. Oh, and 100% stock KFP 24 installation. IONosfear1.craft -Slashy

I strongly disagree with this. Real life aerodynamics are radically different from KSP aerodynamics. My advice is to let form follow function. Build whatever works best in KSP and don't worry about what real hypersonic spaceplanes look like. Best, -Slashy

Kerbal Propulsion Laboratory. You can design and build new non- stock parts (wings, engines, etc.) through a virtual "KPL" facility, but here's the kicker: The add-on generates the final part through your experimenting with parameters in the interface. You could have a virtual materials lab, virtual wind tunnel, etc. The better you understand the real world physics, the better parts you can make.

For a "failure", this is an awfully good one! Way to go! -Slashy

Just to be clear, is this an SSTO challenge, or are we permitted to drop dead weight? Best, -Slashy

Yeah, it's all good -Slashy

We're doing it through very careful attention to weight and balance (especially weight!!) and a ridiculous amount of trial and error with recordkeeping. These things accelerate painfully slowly in the lower atmosphere and don't really make much speed until they get up above 20KM or so. If you can beat this challenge, you'll be well on your way to making something that'll work on Eve. Good luck! -Slashy

Yes. Everything that is attached to it on the surface must remain attached all the way to orbit.

Your CoL was also a hair below your CoM, which creates a torque moment when you encounter air at high velocity and low AoA. For best results, try to get the CoL directly behind the CoM. -Slashy

Ion planes are the one method that has kept us from declaring this outright impossible. They can work in theory... but in practice so far we have yet to make Kerbin orbit with one that doesn't infiniglide. But perhaps an ion glider coupled with something else? *shrug* Best, -Slashy

Godranus, No, all of the control surfaces still infiniglide. The small CS is just the most efficient at doing it. I can't comment on how they behaved before 23.5, since I wasn't playing KSP back then. Best, -Slashy

I'm also pretty sure it's impossible using stock parts without cheating. And I also agree that it's not all that much fun to bang your head against a challenge that doesn't look even close to doable. But this challenge is about answering a question, not having fun. As for the Kerbin Ion glider, I have posted a challenge for that. http://forum.kerbalspaceprogram.com/threads/85728-Ion-glider-collier-trophy! That one is maddeningly close to possible, but hasn't been beaten yet. It's fun, but burns you out... Try your hand at it -Slashy

Certainly not calling you that! I really want somebody to succeed at this, and whoever does will have a rightful place in KSP Valhalla. Best of luck! -Slashy

Reaver, Hydrogen balloons would probably be ideal for this job... if they existed. As for the rest of it, it would negate the entire point of SSTO. The idea is to create a vehicle that could make round trips to the surface of Eve and back to orbit without needing anything other than fuel. Staged landers/ ascent vehicles aren't a challenge. We've already figured out how to do that. The entire point of this challenge is to attempt to answer *definitively* whether an Eve SSTO is possible with stock parts and without resorting to cheats. Best, -Slashy

Really, your best bet (assuming you're using wings) is to use engines that have the best Isp in atmosphere coupled with the best Isp in vacuum at the top end. Happily, these are both the same engine; ion thrusters. They beat the stuffing out of everything else in the game for pure Isp. Which is a good thing, 'cuz using wings means that your Isp requirement is going to be much higher than a pure rocket due to the drag losses. Of course... nobody has (as of yet) created an Ion SSTO from Kerbin, let alone Eve. At least not one that doesn't infini-glide...

Well... the rocket equation still holds. An infinitely large liquid rocket will never exceed 9:1 Md/Mw due to the tanks themselves. This translates to 21.6 * whatever Isp you throw at it. 17,244 M/sec at the absolute limit. Assuming that you hold the LV-N to .5G at Eve (injection and circularization), you're looking at 7.2MT total mass. 4.5T of this is the LV-Ns themselves, so setting aside your skipper, payload, and the fact that you're carrying largely-empty tanks, that leaves 2.7T of fuel. This yields (and I must stress that the actual value would be a lot less than this) 3,689 M/sec DV. Now remember that your Skipper is 3 tons, which means that as a practical matter you couldn't inject a skipper into orbit using 2 LV-Ns even with no fuel tanks whatsoever and infinite fuel turned on. But for the sake of argument, we'll let that go. You still have to make 4,800 m/sec from your Skipper to get the LV-Ns to the point where they can finish the job. Skipper's 3 tons. The LV-Ns are another 4.5 tons. Crunching the numbers yields 4.61 mass ratio. 42 tons of fuel, not counting the tanks themselves. This is well- over the mass a Skipper is capable of lifting at even 1G from Eve. So even taking all those liberties, this doesn't work from either end. It's too heavy to get off the ground, doesn't account for the mass of the tanks, and if it did get far enough to kick in the LV-Ns, there'd be no fuel left and the LV-Ns would be too weak to inject it into orbit anyway. This isn't counting the payload. But still... you might stumble across something we've missed and the math *could* be wrong on this. KSP, after all, isn't a perfect model for real life. Sorry to be the bearer of bad news! -Slashy

Yeah, that thing's kind of a beast. This one's 55 tons fully loaded and is designed to traverse rough terrain to the launch point and refuel on the surface using rovers. Best, -Slashy

Found it almost instantly. Perhaps if the lighting was at a different angle, it would've been harder to spot.

Unfortunately, yeah. The DV isn't additive like that. Best, -Slashy

/me glances at leaderboard, eyes TheKutKu suspiciously... teehee, -Slashy

Mahnarch, If you imagine a 2 dimensional plane parallel with the target docking port, I'm talking about getting on the proper side of it so's not to have a fender-bender in orbit. I always do that step first, before I begin translating to line up with it. Best, -Slashy

'Zackly. Infinigliders aren't technically illegal, but I still consider them cheating. Still and all... we're talking about carrying a ton of payload as high as possible without expending any fuel, so the concept itself is a cheat. I don't know how to make a kraken drive. I bet that'd get the job done handily!

I cheated like crazy I recommend using lifting surfaces for rotors instead of wings. They actually provide *negative* drag. And make them vertical instead of slightly-inclined. Best, -Slashy

Affirmative. Best, -Slashy