wumpus

No solar panels? A bit risky for my blood. I like to unlock electricity first. This means solar panels (and I can hit Minmus first, while you *can* get to the Mun without solar panels, it is a mad rush to get back before your power runs out [not sure how turning off batteries works in 1.2]) *and* Probododyne OKTOs. OKTOs let you send Bill instead of Jeb or Val and get full science for every biome you encounter. Is the service module really needed? Even Jeb (and Val) can spacewalk out, take the science, and then bring it home for full value even if the instruments are burned up. And you *will* unlock spacewalking if only to plant that flag (you certainly want the soil sample: it has the highest science value of anything). If you have unlocked fuel transfer (I think it requires a science upgrade, so it doesn't buy you much else when funds are tight), you don't need both LV-909 engines. Just put one on top of the capsule (the side chutes are included in the original rocket) and keep pumping the top fuel to the bottom fuel tank. While it barely saves you any mass, saving mass in the second stage is always good (but likely not enough to justify upgrading the science building just for that ... although if you can stretch this into a multiple biome Minmus rocket it probably would be. Definitely check the delta-v delta from slapping additional thumpers (and attach them directly to the other thumpers, you don't want to pay the funds or the parts in adding additional decouplers). Finally, I would only suggest adding solar panels and the service module delete for new players. While spacewalking is tricky, this is the easiest spacewalking to do and a good place to start. Pumping fuel while getting into orbit probably isn't a good idea until you can achieve orbit in your sleep. Do not underestimate the shear thrust nor the cheap delta-v SRBs can provide. And once you unlock both kickbacks and AV-R8 winglets (the ones that give you the control you need) it is hard to justify using anything else as a first stage (unless recovered). [Hint: often you can get away with aligning two AV-R8's North and South (for East-West control). This lets you control the gravity turn and rely on SAS for North-South control [which should be minor]]. PS. Once simple trick is to use a single LV-T45 and change the rest to LV-T30s. This works even better once you unlock fuel lines and switch to asparagus staging (the LV-45 is slightly more efficient in vacuum, but I suspect the lower mass of the LV-T30 helps enough even without aspargus tricks.

Considering that Harvester started by writing a "simplified orbiter" (and the first discussions/announcements of KSP were in the orbiter forum), I would be painfully embarrassed if they deleted it.

Chia pet? [for those who didn't live during the era/area where these ads were broadcast, it was a plant+"flower pot" such that the plant assumed the shape of the pot.] I'm guessing the Russians don't have a solution either. I remember reading during the cold war how the Russians loudly broadcast all of NASA's failures, except the "space toilet". As bad as it was (NASA kept insisting that more "potty training" astronauts would fix the issues), the assumption was that the Russians were limited to classic "go in bags" and were having long term issues even with that.

That's pretty much the catch. Reactors are small, containment is bigger, shielding bigger still and finally cooling is massive. And even at 100% efficiency (Carnot says "Hi! Nice heatsink you have. Especially all that nice vacuum.") means that you need a cooling system (again, radiators in vacuum if you are in space) that radiates a Watt for each Watt of power you produce (and multiply that by the inefficiency when you take that into account). Earth cooling systems are bad enough (and typically only built with massive water supplies nearby), but space makes reactors questionable (for areas where PV solar is possible. And if you can build gold-foil cooling radiators you can build gold-foil mirrors to collect the sunlight).

Don't forget that the command module went into Lunar orbit. Only the lunar lander had higher delta-v requirements. So even adding a heat shield meant that it required more fuel, which meant more fuel+thrust to stage 2, which required more fuel and thrust for stage 1 (which lifted off with a TWR roughly 1.1 and simply couldn't afford *any* more mass above it). Then there's the mass of the parachutes (just look up the issue of spacex preferring powered landings vs. parachutes to know how much they weigh) and you start to see why this really isn't an option. Don't forget that JFK announced "We choose to go to the Moon" in September 1962 and Apollo 11 landed in July, 1969. Adding 6 more months to the schedule would result effectively in failure, and I'm sure NASA was cutting *everything* that wasn't needed off the schedule. Recovery wasn't needed, wouldn't lower costs significantly (assuming zero extra mass: this is pure fantasy. It would massively increase costs [thanks to requiring a different design for stage 1] to attempt to return the command module. Recovery of the F1 engines is far more believable, but probably wouldn't work). Much of engineering isn't about "doing x". It is managing the complexity that gets you from here to "doing x". The whole point of going through Gemini to Apollo 10 was about managing that complexity and proving each part did its thing. Recovering the command module was unnecessary complexity and wisely dropped. I would have thought that KSP taught that lesson pretty well (although things like just how badly recovery propagates complexity isn't well modeled).

That's weird. Which one? There were two demos released. One was based on the .18 version (basically the last free edition, presumably altered to not accept mods and a few other limitations) and another based on the 1.0.0 release. I don't remember the 1.0.0 demo being unplayable (I think I landed on Minmus), but I do remember some nasty bugs when the main release dropped (some of that might have been steam bugs, I think there was a nasty conflict between stale code and new code that made parachutes unusable. Completely redownloading fixed that).

Why should you go to a parking orbit and not a direct escape? Easy, parking orbit because you can't create a maneuver node on the launch pad. If you want to determine the differences between direct "escape" and parking orbits I would suggest testing via munshots: they can be easily planned without maneuver nodes (just use them for fine tuning and adjusting your encounter). This should let you determine if the delta-v savings are worth it (let alone having to manually time your launch). [I think this second paragraph belongs in some other thread]. Note that while TWR appears to be confusing, I'm fairly sure you shouldn't throttle engines down to achieve your "ideal" TWR (unless it is over 2.0 or something extreme). I'd recommend adding kickbacks (the biggest SRB) until you have the TWR you need and leaving them all at full thrust (if you have 5 kickers at 80% thrust, you nearly have to do better to only light 4 on the pad [at full thrust] and then light the last when you stage the 4. But 2nd stage SRBs so rarely make sense that I suspect you would be better off with simply 4 at max thrust and use liquid rockets for the rest).

I would expect a lot of the "old knowledge" is either still present or in tutorials. The stuff you don't see anymore is obsolete due to more accurate physics models. Ignored stuff that still works: Asparagus staging: While it is often more efficient to simply use a larger rocket, asparagus staging was used to build large, efficient rockets without massive parts. The key thing to learn about this is that you need not always stage vertically, and that drop tanks still come in handy (our fuel tanks are considerably heavier when empty than in real life). One reason asparagus staging was so popular was that due to a trick of the atmosphere, you wanted to keep your TWR=2.0 pretty much through your entire ascent. Having equal sized asparagus staging made this work. For multiple asparagus staging (i.e. more than two tanks+engines) it is almost certainly more efficient to at least double the number of fuel tanks on the stages dropped earlier. - One useful trick in the early game that comes from this idea is to put a fuel tank (roughly twice the size of your "last stage" tank) on top of the capsule (via staging couplers). As you burn the "last fuel" tank keep pumping fuel from the top tank [if you are in career mode you will need to have at least the science building upgraded, I'm less sure about the requirements each revision]. This basically gives you a "free staging" without the need to buy or carry an extra engine. Solid rocket boosters [SRBs] still work. In the current game, they seem to exist for the first two-three career mode launches, and are only seen again for efficient designs with the kickback boosters. Nevertheless, they not only have cheap delta-v, they have even cheaper thrust when you need it. In general, you will still fire all your SRBs on the pad (although missions that simply specify "escape Kerbin" might be ideal for a second [one size smaller] SRB stage). In earlier editions it was possible to get to the Mun via multiple "layer cakes" of RT-10 "hammers" (the then smallest booster possible), but I doubt that it is possible to stabilize such a system now (although you wouldn't need nearly the struts). Before career mode there were these suggestions for exploring KSP: http://wiki.kerbalspaceprogram.com/wiki/Campaigns Many players have been frustrated by career mode and feel it was a bad move. Being aware of the old campaigns gives you more options. Note that since the whole point is to skip the bits in career you don't like, don't bother with docking if you really want to go to the Mun (although I strongly recommend going to Minmus first, once you adjust your angular inclination it is much easier to get to*, land [the purple bits are all flat: this is important], get off, and get home). * technically it takes about 100m/s more delta-v to get to Minmus, but you save that in landing/relaunching issues. One "lost art" is the munshot. My guess is that it predates maneuver nodes, but I wasn't around for that. Simply wait until the Mun appears on the horizon, and then keep burning towards it (like going to orbit and keep burning until you get an intercept). Expect to stop and create a maneuver node correction once you get to space (you should be well on your way). This is *slightly* more efficient than a parking orbit, but typically only used to get to the Mun since you can't create a maneuver node on the pad (a significant bug, but apparently baked deep in the code). Don't sweat too much over it as you don't gain all that much by not using a parking orbit (NASA typically used it for probes, but I think stopped with New Horizons. I wouldn't be surprised if NASA probes to Mars (and closer) still use parking orbits). And of course, signs you are watching an obsolete tutorial: Player flies straight up for at least 5000m to get to orbit (sometimes much, much, worse. But there may have been reasons to go even 15,000m before .90). Rocket is covered with struts, or built like a flying pancake. Player throttles down the engine. This is somewhat controversial as some data shows that launchpad TWR should be roughly 1.3. But typically if you are paying for the weight of a more powerful engine, you need to get all the thrust out of it. Throttling the engine was crititcal in <.90 play as you wanted to maintain the "ideal TWR=2.0" through the atmosphere. Don't do that now. Player simply smacks into the atmosphere without carefully lowering PE to some reasonably value (I like 30,000m). Before .90, you could simply set up a return from the Mun that was a collision course and the souposphere would slow you down enough to stop you. Player hits the parachutes at the last second, slowing from ~2000m/s to 5 m/s in a second. Sometime after 1.0 [main] parachutes are destroyed if deployed faster than ~250m/s (drogues can be deployed much faster, and quickly take you down to safe parachute speeds).

Then the airship still doesn't matter. Even if it only moved the airship ~1000 ISP is lousy for a jet [read high bypass turbofan]. And it won't operate without the airship (or until at least one stage with TWR>1 launches it into a relatively long-duration flight).

You've taken this thread so seriously you stated that Skylon is an aircraft. When it flies I'll call it an aircraft. Right now it is as much a paper airplane as any other SSTO. Skylon (and the especially the SABRE engine) is only interesting between mach 2-6 in the atmosphere. Once it breaches the atmosphere (or possibly just hit mach ~6, although atmospheric separation remains an unsolved problem and is dangerous to test) it is likely to launch the payload. Also, just how much oxidizer do you think you will need to carry the concorde from service ceiling to out of the atmosphere (at no more than mach 2). Take the amount of fuel needed to get to 40,000ft, multiply it by a factor of 5 (which *still* isn't out of the atmosphere, but 200,000' is impressive), then multiply it *again* by a factor of roughly 16 (the factor of 5 was for your fuel. The factor of 16 is for the oxidizer). You aren't getting to space in the Concorde. It isn't built for it (this is ignoring the whole issue of replacing the engines with things that can run with either air or oxidizer. My guess is that the time you can run on air is so limited to not even bother, which would be a serious nail in the coffin for the entire concept of Skylon if true).

Pretty much the only time you will see a difference is when you are tracking one object with a background moving in a different direction (or some other combination of two sources of reference). In KSP that is likely only going to happen during docking (in chase view) and the occasional eclipse (which are sufficiently impressive that you don't want to notice framerate issues while they occur). There's a reason why flight simulators and driving games only "need" to be ~30fps and first person shooters (especially when circling enemies) need to be ~60fps. I always hated the opening for Oblivion (a wildly open fantasy role playing game): it pretty much needed ~30fps for its relatively slow pace, but the opening includes a slow pan of city/castle that shows a few towers passing in front of the city. The game needs ~30fps, while the introduction needs roughly 60fps, and the difference is blindingly obvious. Don't even ask about VR. You might not need to update *everything*, but the "virtual screen" had better at least show what the headset is looking at (with the latency of a 90fps screen). Finding new and interesting ways to cheat at this (and still "look" right) will make or break VR.

I'd be shocked if vaporized material turbines don't convert heat into electricity wildly more efficiently than pretty much any other proposed conversion (although I wouldn't expect water steam to be the final vaporized material, and I suspect at least a cascade between two materials (water as the first, followed by freon)? There's also sterling engines, but I suspect that would be for the "smallest reactor we could build" type solution. RTGs might use peltier-type junctions or thermocouples, but I suspect that they want ultra-simple operation for years without maintenance, and are willing to sacrifice power for it. Once you start bothering with full blown reactors, I'd suspect that standard heat engines will be used.

I put quotes in for a reason. I assumed that had it really been all that easy, somebody would have done it (if only as a mod, and probably part of the real gravity mod) already. My guess was that somehow Squad's implementation made it much harder than I thought (the implementation *has* to be pretty weird: it relies on keeping the active "physics bubble" at the origin of the coordinate system and moving the rest of the solar system in some sort of Ptolemaic system around it). Unfortunately, I think ion engines are too important to simply ignore (and they are probably the key to exploring the solar system, especially by caching fuel at higher delta-vs for human exploration). Although it wouldn't necessarily be wrong if they were only useful with the real gravity mod, 3-body gravity tricks are pretty much the rule with such slow orbital progression.

A lot depends on what you want, and how you can build it. Shielding in space can easily be limited to a single direction (mostly shielding crew, and possibly using fuel as shielding if you are willing to eject your reactor before burning the fuel). Cooling is probably the biggest issue, and is proportional to power. Don't think of things like nuclear subs flowing through arbitrary amounts of cooling water, think more like Chicago Pile-1 (step 0 of the Manhattan Project: create *any* nuclear reaction) which didn't appear to have any cooling whatsoever (nor shielding). What you have is more like an RTG with a bit more control of when the radioactive fuel is emitted ("real" RTG's simply take the power as plutonium decays at its fixed rate). Building a reactor on the Moon or on Mars is still wildly different from in space. You get at least *something* of a heatsink there, in vacuum you are limited to radiating heat into space. Don't be too surprise if your Heat->electric power conversion is so inefficient that you wind up carrying more radiators (that are heavier) than solar panels (assuming you are within Mars or so).

Basically, for the simplest case blimps and dirigibles should, at least in theory, scale better than airplanes (read stratolaunch and to a lesser degree the L-1011/Pegasus system orbital makes. It should have the same advantages: Less "delta-v" to orbit since you aren't wasting power fighting the atmosphere as much No wasted fuel for inclination changes: just start from the right latitude and you won't need the inclination change the "right latitude" can be right on the equator for maximal free delta-v due to Earth's rotation. And it will likely fail because it is easier to stretch the gas tank that little bit (1-2k delta-v?) to cover all of the above instead of building a complicated blimp-to-orbit system. Especially one that involves blimps docking with blimps, and passing things as heavy as a rocket. It might mean a rocket half the size of a sea-level launched rocket, but it is still cheaper to design and build rockets twice as big as such an air-based system. Note that such a system almost certainly will compete with the "new guys". Rocket lab and Firefly Space System each picked up a few million from NASA for small satellites, I suspect that any air launch would compete with this and not with Soyuz, Spacex, and Orbital. The real key is that even if you can get the money will be trying to build *both* the airship and rocket with a few million dollars (note that the scaling issues are *nasty* for such rockets, and why Pegasus succeeded at all).

Just how different are Kerbal Ion engines from VASIMR engines anyway? The key point is that all KSP engines (except SRBs) can be throttled. Also KSP Ion engines already have wildly more power than any ion engine should (which *still* isn't enough to really work in KSP, they need to allow "physicsless" engines that include thrust (note that they are already accelerating thanks to one gravity source in the SOI, they "just" need to allow slighly different acceleration). SABRE made sense thanks to KSP's silly small planet. Making such an engine should be easy for Kerbals, harder for us.

If NASA can get talks through that successfully included projects and use of the NASA name and graphics, I'd be shocked if there weren't any talks between Squad and Estes. My guess is that both side valued their side too high and they quickly drop the whole idea of a deal (I'm reasonably sure no cash changed hands with the NASA deal, I'd expect Squad to be paid for a such a Kerbal deal, and presumably Estes wouldn't pay enough (possibly because the money wasn't there and largely comes from old hands). Don't hold your breath (although Estes might rethink it if they saw LEGO KSP products in the hobby stores they sell from).

Do you have more than 4GB of RAM, and are using 64-bit KSP? Then the amount of RAM all the mods are taking up isn't an issue. I'd be a bit wary about all the lines of code that might be there, and especially assuming that the mod coders were unlikely to test their mods against more obscure mods (a mod that interferes with mechJeb or KerbalEngineer isn't likely to last). Even if you run into memory issues, the old tricks (wasn't OpenGL one of them?) should still work to restrict stock memory usage in KSP-64 (even though the 2GB limit won't be hard anymore).

Policy decisions by turf battle. How all the critical decisions are made (then again, do you want Congressmen making arcane details about patents? Reality and public perception have almost no correlation). It's nice to know that paper wasn't terribly serious (and presumably the guy who wrote it new either that MP3s are lossy, and/or that they aren't reversible [enough for genes]). You obviously can register such a copyright, enforcing it is another battle.

According to wiki: "The telemetry system relayed data back at an estimated rate of 9.6 gigabytesper second on 320,000 channels on 14 frequencies. Commands could be sent to an ascending N1 at the same rate.[19]" Is this remotely correct? It would be fairly impressive even during the 90s internet boom, let alone with discrete transistors during the 60s-70s. While Seyour Cray might have had been dealing with more data in the CDC6600 and CDC7600 at the time, they didn't need to strap 30 rockets to it and blow up a N-1 to test it. I wouldn't claim that Cray* could get that to work. * actually Cray (nor Chen) got any of their machines to work on their own, all of their working machines were finished by the same guy (possibly Thorton, but google has let me down).

The big catch is we know that reactionless drives exist in this universe: put a big old spotlight on the back, and you will generate thrust. One big difference is that it is fairly easy to note that the momentum changes (due to the doppler effect) as you speed up wrt to outside observer, so it doesn't appear to be capable of perpetual motion. While Scott Manley posits a "break point" where an em-drive would be capable of such motion (a bit premature since we know even less about why a drive has measured thrust than that it if it has measurable thrust at all), it isn't clear that it wouldn't scale along with relative velocity to have no such break. The other thing that even if such things exist, right now they have no other use than interstellar probes (and probably a second stage at that). Ion engines are so more efficient that em-drives are of value only in proving their existence and questioning the importance of momentum (and the conservation thereof*).

I'm willing to believe that for anything past the moon (and not limited by life support), chemical rockets are rarely the answer. Once you get to 4 digits, don't be surprised if ISP isn't so important (unless you are constrained by the price/availability of Xenon). This can be pretty bad. Using NERVAs with water would reduce ISP from >=800 to no more than hydrolox (and likely worse as that assumes hydrolox temperatures in the nozzle (which is presently the limit of our technology, then how do we contain the reactor that heats the water up hotter?)). Presumably you could get better than chemical ISPs out of helium (and presumably the James Webb telescope will pioneer holding liquid He indefinitely), but expect a big, big hit. But it is the only known high power (compared to everything else with a high ISP. Don't compare it to a real rocket) interplanetary engine.

I've given up on knowing what a "true gravity turn" is. Especially if it relies on atmospheric conditions and not gravity. The optimal path on Mun, Minmus, or any other body without an atmosphere basically involves defining an orbit slightly higher than the highest mountain and then following the flattest elliptical path to that orbit that avoids the surface (i.e. mountains and such). Of course, even then there is no way to do a "gravity turn" without the necessary atmosphere. Maybe you can ask Norcalplanner, he was the one I was replying to.

Elon Musk seems to be also pushing for an advanced "irridium-like" space communications network. If you are building a constellation of ~4000 satellites (or even 400), then something like the Falcon Heavy (or better yet, the BFR) looks ideal. These would pretty much require more birds per plane than such a rocket could lift.

One huge issue with VASIMR is that it uses hydrogen as a fuel. This makes "long, slow, efficient" burns less efficient if all the hydrogen escapes before it is used. Ion systems tend to use Xenon, which has the unfortunate property of being unbelievably rare. It *could* be replaces with argon (more common than CO2, but that would cut the efficiency by roughly half). I'm pretty sure NASA launched a probe with three ion engines, but I suspect that the goal was reliability not more power (they are typically limited by the energy source, not the engine). For any large probe/cargo run, I'd assume that you can either scale up an ion engine or simply spam plenty of them Kerbal-style. The real catch is you have to provide power for all those engines, and that won't be light/cheap. Don't forget modern gravity tricks (not just slingshots, try fuzzy boundries), such things come into play when using extremely slow spacecraft (unfortunately you can't really use Obereth unless you have something like VASIMR).