DoctorEvo

Please do. Even though I don't use Milkshape, being able to actually SEE the non-modelling steps (such as using the SDK) should help me better understand what else I need to do. Why would you want to sculpt a rocket part, anyways? Sculpting is more of an organic rendering thing, and rockets usually aren't very organic.

Only one issue here; most of the heating during reentry and high-speed flight is due to rapid compression of the nearby air, not friction. But yes, for aerodynamic heating to be dissipated, it must be either be radiated (either directly, or indirectly through some kind of coolant loop); or dumped overboard in the form of ablated materials (or, in the case of the SR-71 or X-30, burnt fuel). Otherwise, it must be absorbed or 'soaked' by the craft itself - which will result in overheating if prolonged for too long.

Nnnnnnnoooooooooooooooooooooo........... Sorry, man, but you're wrong. I'm certain of this. I explicitly remember being taught that escape 'velocity' is a misnomer, but gets used anyways out of habit. Kinda like how kinetic energy is generally expressed in terms of velocity, even though it doesn't matter one bit what your direction is.

How is requesting that multiple different proposals of widely-varying design be developed NOT competitive?! The Air Force was, quite literally, putting Martin and Convair head-to-head not only during the preliminary proposal process but all the way to full-scale deployment. Convair, having much more experience under their belt with extensive postwar studies into ICBM concepts (see MX-774), was much quicker to the punch and had Atlas ready within MONTHS of the R-7's first test; and on those grounds, they 'won' unchallenged business from the Air Force (eager to avoid a 'missile gap') for nearly two years. Then Martin finished the Titan, late to the game but with a product much better-suited for the deterrence role, and gradually took the lead as the Air Force phased the larger, much more survivable, and faster-responding Titan into service. I dunno about you, but that seems like competition to me. Yeah, well I hardly think the comparison of Nova and UR with Apollo-Saturn is representative of the norm. Both were exceptions to the rule - the Soviets' caused by hesitant and indecisive leadership by the bureaucrats that were responsible for the central planning, and the US's caused by a wide variety of reasons, but mostly that no single contractor was willing to take on the massive development costs of such a large project by themselves (and with good reason). Pretty much the ONLY solution, it seemed, was to try and use existing hardware as much as possible, from multiple manufacturers. Of course, ABMA was the only team that was interested in or capable of organizing and heading-up such a project. Thus, the Saturn family was born. And, while the Russians WERE secretive about their space program, I think the development teams themselves were all pretty well-informed what other bureaus were up to. How could a spacecraft with braking rockets attached to its parachute lines POSSIBLY be a deathtrap? Well, there IS something to be said for having options. But Saturn was not the right rocket to be using for frequent launch services. Keeping it around for occasional heavy launches (much like the way Proton is used) might not be unreasonable, but even still, a Saturn IB would easily cost several times what a Proton does simply because its design is NOT well-suited to high-volume production. In general, scrubbing Saturn in favor of a more modest and flexible rocket would've been the most sensible answer - for instance, taking advantage of the massive groundwork laid by the cancelled MOL project and using evolved Titan rockets as an interim solution. And I still hold the opinion that the Shuttle COULD have crushed expendable boosters in terms of per-launch costs if it hadn't been crippled by expensive and constricting post-Challenger safety measures. The very nature of the Saturn rocket's design made it horribly suited for a proper assembly line (unlike, say, Soyuz or Proton or pretty much anything that was a missile once upon a time). Again, think of the Boeing plants. They churn out one 737 EVERY DAY out of Renton at a bargain price of around $30-40 million apiece from two parallel assembly lines. Over at Everett, they're shipping in fuselage sections and all sorts of other components from different manufacturers all over the world, bringing them in and trying to fit them all together on a slow, makeshift non-moving assembly line. They get roughly two out per MONTH, for about $200 million apiece. This is very closely analogous to what you're looking at when you compare Saturn's complex production scheme with any single-manufacturer, horizontally-assembled rocket. There's just no comparison. Retrofitting Saturn for partial reuse would be an interesting (and probably expensive) prospect. Overall, I think launches of Saturn V would not be frequent enough to warrant it all by itself. If INT-21 somehow did replace Saturn IB outright (which, contrary to what you claim, does NOT seem to be the intention of the study), then I could see it possibly being worth investing in. Then again, maybe a reusable S-IB would make more sense if the ultimate goal is cost savings. The technology was fine. The industry wasn't. Now I don't KNOW if some big industry player such as ULA or Krunichev or even an up-and-comer like Space-X could pull it off nowadays on their own if a space agency offered them a contract, but it's certainly conceivable. I saw a write-up on a blog where some guy judged it'd be possible for a solo astronaut to ride a Space-X Dragon atop a Falcon-9 Heavy through a free-return trajectory using mostly-existing equipment. Perhaps the industry IS finally prepared to continue such bold endeavors.

Dude, what? If you hit escape velocity and stop thrusting, you're never coming back. Period. Direction is irrelevant.

Not really. The only REALLY centralized American rocket projects that didn't see a large amount of competition were the Apollo-Saturn, and to a lesser extent the Shuttle. All the ballistic missile development was highly competitive on both sides of the curtain, but on the US side this competition spilled over into the space launch business as well. Convair, Martin, Douglas, and Von Braun's ABMA with Chrysler all eagerly threw their hat in the ring for the chance at these high-dollar rocket contracts. And really, it DID show. The Russians had all of ONE operational manned rocket design (the R-7 family) throughout the space race and even to today, and that very same launch system gripped a large portion of the Russian unmanned launch industry as well, with only Kosmos and Proton really even coming close. Meanwhile, the Americans put astronauts on Redstone, Atlas, Titan, Saturn rockets and the Shuttle, and launched satellites on all of these (or derivatives) as well as Vanguard, Scout, Thor/Delta, and several others. Chelomei's flyby proposal and Korolev's landing were BOTH batted around a bit, but eventually Korolev's route WAS selected. And really, I don't think having OKB-52 contribute to the N-1 project would've helped them win at all. It MIGHT have helped things go smoother after Korolev's death and perhaps keep the project from getting cancelled after Apollo's victory, since Chelomei would've been there to take charge, but that might have backfired as well if Chelomei was as bitter as Glushko seemed to be (I don't know enough about the man to make that judgement). Now, the other way around, having OKB-1 help out with the more modest flyby proposal... now THAT probably would've worked out, and they probably would've beaten the Americans to it there. I don't think Saturn was nearly as cheap as you think it was. It was a finicky design that required an order of magnitude more manpower to build than contemporary missile-derived launch vehicles. It could not be elevated whole, and thus required vertical assembly which again requires more labor to work on. It relied on several different manufacturers, and if you've ever been to the Boeing Everett plant and looked at the 787 production line vs. the 747 line, you can easily see why this can be extremely problematic for large-scale production. And of course, there's always the chance that it would end up going the route that the Shuttle did, with some fatal disaster occurring SOMEWHERE down the line (which is sorta bound to happen after you start racking up dozens upon dozens of launches), resulting in a big hearing and a whole slew of expensive and unrelated safety measures that drive your per-mission costs through the roof, and also inflicts a prolonged period of downtime as well.

And your point? There's a REASON moons are larger on average than other minor planets in our solar system, and it would be just as relevant in any other system.

It's something of an exaggeration, but the high weight of LFEs is not well-suited to large, multi-stage designs. For most of the rockets I build, this eliminates the viability of liquid-fuelled design schemes. I certainly KNOW the point where liquid-fuelled rockets gain the advantage over lighter and more modular solid-fuelled schemes, but due to various reasons including my inability to cope with slideshow-esque framerates, I can never reach this optimum in any practical form. I just can't build a rocket that lofts that fuel-heavy, 7-tank liquid upper stage, and for lighter upper stages, solid-fuelled schemes have a lot more delta-V. Plus, heavy liquid-fuelled rockets tend to be ridiculously tail-heavy, and I don't like having to cope with that. So yeah, given all my practical limitations, my solid-fuelled designs generally outperform my liquid ones.

Hey, that's some mission-critical weight savings you're criticizing there.

Well, all I know is that I tried to figure out that friggin' interface and couldn't get anywhere without hitting a brick wall. Sure, I managed to take a sphere and kinda stretch it into a deflated blob of an engine nozzle, but then I couldn't figure out how to do things like... add more nodes to expand my mesh and form a combustion chamber, or to form a set of nodes into a radially-symmetric form after diverging, or EVEN FRIGGIN' UNDO A MISTAKE. And now, the fact that I'm on a MacBook seemed to aggravate things, seeing how I have no MMB and have to use my num-pad to look around, and that half the supposed keyboard commands didn't work (including said undo shortcut). And THEN I found out that Blender 2.5 and onward was supposed to be the version with the NEW AND IMPROVED INTERFACE. My response was quite predictable: Then I downloaded Google SketchUp 8 and life got a million times better. I could now build the thing EXACTLY the way I wanted - structuring the general outline from a few 2D jigs, placing nodes EXACTLY where I wanted them instead of having to stretch them from some arbitrarily-generated primitive, connecting nodes where and when I wanted, deleting or hiding faces at my own whim so that I may work unobstructed behind them, going up to the toolbar for most things and to a conventional menu for more advanced features... and in no time at all, I'd made myself a glorious reproduction of the Atlas V's RD-180: So, yeah. I know I can export it as .dae, but the issue is I don't know much of what to do beyond that. I don't know how to go about making a separate collision mesh and tagging it as node_collider, and I don't know how to go about UV mapping or texturing. But I'm way closer than I was when I was trying to navigate Blender's labyrinthian excuse for an interface.

Somebody did, I think.

...You know what it's missing? Cupholders. Who would buy a spaceship with no cupholders?

Orbiter is EXTREMELY capable if you know C++. But for people like me, KSP is much more capable. I can't build my own rockets in Orbiter; I can't do any engineering in Orbiter; all I can do is pick one of a narrow selection of pre-made spacecraft and go fly it somewhere. To me, that takes half the fun out of it.

Dwarf planets, barely BIGGER than the average Moon? Pluto, Charon, Ceres, they're all SMALLER than Earth's Moon. I mean, I guess Earth's Moon isn't exactly 'average,' but Pluto, Charon and Ceres aren't either. In general, moons are much LARGER than minor planets. Mass just accretes better during solar genesis in a sporadic high-density region such as a planetary sphere of influence than in a vast, distant, unperturbed region such as a distant belts of random jumbled minor planets.

Boosters. Always boosters. Liquids are boring for anything but dinky rockets with just one or two stages. (I bet you think I'm joking, too.) Well, you also gotta realize that he and Thiel were pretty much the ones who made liquid-fuelled rocketry practical in the first place, and he was VERY proud of that fact. And as for that little statistic there... http://en.wikipedia.org/wiki/Solid_rocket_booster SRBs are actually quite a bit more reliable than liquid rocket engines, owing mostly to their rugged simplicity. They do fail much more spectacularly, though. I find that using a single engine is usually more appropriate for SSTO, unless I have more than about 6 fuel tanks. The engines just weigh too darn much to bother with unless you absolutely have to.

'Scuse me? Keep shaving those seconds, pal. You haven't passed me yet.

Unrealistic, yes; overpowered, maybe not. Their specific impulse is ridiculous, but their mass fractions are somewhat low... Perhaps this is a question best saved for the other addon developers. Changing the .cfgs would be easy, but ultimately it would be their choice whether it's worth the trouble modifying their existing parts to comply or not. Sure. Gimme a minute and I'll average a bunch of basic (I'm thinking gas-generator-cycle) engines in each propellant. That'd make a good 'generic' baseline. *edit* LH2/LOX: 4145 m/s (four engines, gas-generator cycle) RP-1/LOX: 2775 m/s (four engines, gas-generator cycle) Hypergol: 2917 m/s (one engine, gas-generator cycle) Weighted engine type efficiencies: Pressure-fed: ~90% of gas-generator, ~80% of chart value (one engine) Gas-generator: 100% of gas-generator, 79-94% of chart value (four engines) Expander: ~107% of gas-generator, 95-102% of chart value (three engines) Staged-combustion: ~109% of gas-generator, ~94-100% of chart value (lots of engines) And overall, it appears that hydrogen achieves closest to theoretical performance most often, frequently exceeding 100% of chart value amongst staged-combustion and expander cycle engines. RP-1 and hypergol propellants never reach the chart value, and their proportionately-lower performance can be seen by the propellant-specific Ve values above.

Really? Because if anything, I get the OPPOSITE feeling. Heck, even when he was at his most hands-on during and prior to WWII, he STILL had someone else (mostly Thiel) do most of the engineering for him. I feel like Von Braun was a visionary, an idea man; and a great team leader, and not much more than that. Oh, I dunno. Any ambitious project such as a space program needs both idealists AND pragmatists. Chelomei was much more pragmatic than Korolev, and this is a large part of why the Proton became so much more successful. I tend to view dual-use technology as a good thing, since it better-economizes development costs of various technologies, often being the very thing which makes these megaprojects possible in the first place. In a way, I feel like the divergence of military missile technology from space launcher technology was a large part of the reason the space race came to a halt. Besides, I kinda feel like the military applications of UR-500 were doomed from the start. By that time, warheads were ALREADY getting smaller and lighter, response times were becoming ever more urgent, and it was pretty clear that solids were soon becoming the preferred propulsion method. Again, I think it was largely a sign of the times. Manned spaceflight is expensive and risky, and since it was no longer a matter of national pride, it got dropped in favor of more practical projects. The Shuttle was intended to make manned spaceflight useful and inexpensive so that it'd be a worthwhile investment again, but the tremendous reaction to the Challenger disaster utterly crushed both those notions.

I'd need to see the .cfg. It also depends what fuel tank you're using with it... I'd need to see that .cfg too. This is part of the reason why I wish the addon developers would adopt a standard .cfg spec for propulsion components. That way, it'd be easy to tell if an engine or fuel tank is unrealistic right off the bat, and also ensure that mixing parts from different sets or developers wouldn't cause ridiculous performance (in other words, guaranteeing parts behave exactly as they were designed to no matter what other parts you use them with). Of course, it sounds to me like the E-series is just plain overpowered in general, no matter what fuel tank it drinks from.

But I already used all my laughing gas as rocket fuel...

I saw boosters and got excited, but then I saw that an SAS was required - in the FINAL STAGE, no less. LAME. (Also, you're right - the weight of added decouplers kinda defeats the purpose of optimizing gravity- and aero-drag, since it increases both anyways. A certain amount of moderation and staging is beneficial, but it's important not to overdo it.)

Yes, but they had THE SAME EXACT JOB, which in a way makes it ten times worse. At least Glushko and Korolev needed eachother's services to finish their own respective jobs rather than being in direct competition... Actually, I kinda feel like Glushko would be more agreeable under Von Braun than he was under Korolev. Von Braun was a lot more charismatic than Korolev, and seemed to be much better at getting what he wanted out of his colleagues. Also, Von Braun was more pragmatic and conservative (as opposed to Korolev's idealistic and bold innovation), and in a way that would help keep Glushko (an ambitious and proud innovator) from developing the inferiority complex that eventually led him to sabotage Korolev the way he did. Also, Glushko never got Von Braun thrown in a gulag.

I kinda figured that was your reasoning. But that just means that the LFT is ridiculously overpowered. Also, it means it involves more math (i.e. another arbitrary conversion factor) for anyone who wishes to adopt this system. Also, are you sure it's not 25 kN*s/unit? I went back and figured what it'd be if you wanted to make the stock tank behave like a proper LH2/LOX tank, and I got roughly 19 KILOnewton-seconds per unit (of course, this is presuming that the game units are tons and kilonewtons - and seconds, of course). 'Simple math' to you and me is still another step for other developers who might want to use these standards. Developers who, more likely than not, are just looking to make a simple, fictional, generic-yet-functional part. And if we can make it so these generic parts are NOT inherently unbalanced and overpowered, I think there's something to be said for that. Also, the 'chemical potential' from that chart is in no way absolute. Alright, but do you agree that the numbers could afford to be knocked down a bit to represent more 'typical' than 'ideal' figures? Because as it is, it appears that if you use any of those values from the table outright without penalizing your engine, you've already got unrealistically efficient performance (in fact, I can't find a single I can only find one real engine that exceeds the performance listed in the table, despite the table's somewhat low combustion pressure of 1000 PSI).

Says the guy who suggested a 'quantum veil...' This thread is turning into a cheesy Syfy movie.

25 N*s/unit, huh? ... Oh, I see. You made it compatible with the stock engine. That actually means it is NOT in-spec with the RD-180 parameters you derived in the other thread, since those were in compliance with a 1 kN*s/unit spec that would satisfy the thrust=consumption condition. So yeah, not EXACTLY what I had in mind (I was thinking just the straight 1 kN*s/unit for the sake of simplicity, and perhaps retroactively edit the stock parts to comply), but I guess it's not TOO difficult of a conversion. The only other issue was that if I had to pick one of the stock parts to be 'broken' or unrealistic, I wanted it to be the engine and not the fuel tank, since it's TWR is all out of whack anyways (actually offsetting its absurd ISP and ultimately making it 'balanced' anyways, whereas by the 25 N*s/unit spec it is seriously underpowered). But, I dunno. I'd love to hear your thoughts as well. Also, one more thing - I think I'd like to knock down the propellant Ve values a little more than what's on that chart I showed you, as they seem to be significantly more than real engines actually get out of said propellants. I'd like a generic engine with an exact-to-spec fuel consumption to actually be representative of real-world performance and not overpowered if possible. I'm thinking: LH2/LOX = 4200 m/s, RP-1/LOX = 3000 m/s, Hypergol = 2800 m/s as a starting point, based on performances of typical engines using these propellants (for instance, despite the higher performance of hypergolic fuel relative to RP-1, hypergols are generally used in pressure-fed orbital maneuvering rockets rather than in main engines, and thus achieve lower ISPs in their most common role), and engines that achieve exceedingly-high efficiencies may be modeled as such on their own. *edit* Actually, scratch that about penalizing hypergolic fuel based on the performance of pressure-fed engines; it's better for gameplay if we have all the various engine types cross-compatable with different fuel types. Generic fuel tanks could be designated by their fuel type, and generic engines can be designated by their engine type (with pressure-fed engines being the lightest but least efficient, and staged combustion being the most efficient but somewhat heavy). Then allow players to mix and match to their liking. Though it DOES appear that I can't find any high-ISP hypergolic engines whatsoever... not even the Viking from the Ariane or LR-87 from the Titan II seem to match RP-1-fuelled rocket engines (RD-275 is the best I can find). Maybe 2900 m/s would be appropriate... even THAT is a little high.