DracovaXIV

That's an excellent question. Yes, they basically are. It's actually quite a bit worse than that: the fissile material that comprises the RTG's core has a property known as a half-life. The atoms of the core are unstable: they want to transmute to a lower energy state, which means turning from one atom to another one - decaying. As they do this they release various particles and immense amounts of heat. This process of radioactive decay happens whether or not you're there to capture useful energy from the process! So, if you were to pull the Plutonium core out of an RTG, you wouldn't be able to "store it for later" no matter what you do (well, other than doing all kinds of wacky impractical tricks with relativistic time dilation). The core will degrade with time. Plutonium-238 is actually kind of a bad source of energy IMO. Obviously it's good in the sense that it exists and it's a byproduct of other stuff; use it if you can. But it's an artificial element. With a half-life of 87.7 years, it essentially doesn't occur in nature; that half-life is like an eyeblink on astronomical timescales. You can't make it last longer, and you can't really make it give up the ghost any faster, in exchange for more energy. This is in stark contrast to Uranium, which you can moderate the decay of: you can make a Uranium reactor core burn white-hot if you wanted to. Uranium is also found in nature, in various ores, so if you have a Uranium-powered spacecraft, you can potentially mine the stuff on faraway worlds and enrich it for reactor use. But I digress. The main advantages of Plutonium-238 is that it's got a half-life that's long enough for human purposes (rather neatly seems to match human life expectancy), and it's very weakly radioactive. It's an alpha particle emitter. You can block alpha particles with a sheet of paper. Elemental Plutonium is extremely toxic, but Plutonium oxide is nice and inert. The main danger is how hot said samples are to the touch, really. Obviously, I have only a surface understanding of all this stuff, but I've learned quite a bit about the mighty atom so far. One more note regarding RTG half-life. Theoretically it's going to be the same as the core's half-life, but in reality, it can be quite a bit shorter than that because of the various other components of the RTG taking damage over time from radiation, heat, possibly mechanical damage (if it uses a reciprocating piston or something). The efficiency of thermal conversion with solid-state components is approximately 5% (more robust, cheaper: ~4%, cutting-edge tech: ~6% or so). If you use a mechanical piston, such as a Stirling engine or Brayton turbine, the efficiency goes up to around 30-40%. Generally, higher efficiency is possible if you use the core to drive a fluidic (gas or liquid) coolant. Such machines don't stand up well to decades of use, however. In case you're wondering, the theoretical highest-efficiency thermal cycle known to science is the Carnot cycle.

I've just updated the add-on. The new version is v1.1. This version contains two more reactors, using the texture provided by @sebi.zzr. I have configured these as Strontium reactors. Part costs have been balanced. Strontium reactors are somewhat radioactive, unlike Plutonium, which is safe enough to power a pacemaker implanted inside a person's body. Consider this when building your spacecraft (oh, who am I kidding! Radiation interference and lethality aren't modeled in the game yet). Strontium is also much cheaper than Plutonium. It's also not as power-rich and does not last as long, however, the power of an RTG is largely dictated by its heat radiator area. The core can easily match a desired power output by being made slightly larger.

I've got a few interesting (I hope) things to report. Pretty soon there's going to be a v1.1 update to this add-on. I've been tweaking the game balance of the reactors, mostly related to their in-game cost. I'm also most likely going to use the texture provided by @sebi.zzr to make two more reactors. Now: I've done a little bit of research regarding space nuclear reactors. There's a number of real-world isotopes to choose from for RTGs. I could put together a list from what I've found, but most of them are quite easy to eliminate for practical reasons. Curium and Americium are very expensive and require significant shielding; Curium-244 is interesting in that it has a power density of 2.84 watts/gram and a somewhat reasonable half-life of 18 years. That half-life is sufficient for space missions and the power density is better than that of Plutonium-239 (0.56 watts/gram). Polonium-210 has a fleeting half-life of 136 days and a massive power density of 141 watts/gram. It also only gives off alpha radiation, with very little gamma, which makes it generally safe to use in RTGs that get handled by crew. Besides Plutonium, Strontium-90 is of particular interest because it's extremely cheap (common "waste product" of nuclear fission), has a nearly identical power density to Plutonium (0.46 watts/gram), and a reasonable half-life of 28.8 years. It gives off beta radiation and bremsstrahlung, however, which makes it deadly to crew and harmful to sensitive electronics. So the question is: would anyone be interested in reactors using Sr-90 in KSP? The only real difference would be low cost, since radiation isn't modeled in-game yet. They wouldn't be any weaker (because RTGs' limiting factor to power generation is their ability to convert heat; a reactor core could easily be made slightly larger to give more power output), and perhaps the half-life might be an issue. Then there's the question of large reactors that use likewise large radiators. I'm using real-life and projected future numbers to come up with some ideas. The confirmed track record for space reactors is ~10 watts/kg. Realistic ones that are possible with modern-day technology can produce ~25 watts/kg. There's an optimistic projection for the near future that might produce ~100 watts/kg; and finally, Chang-Diaz, who's the current NASA shill for VASIMR, assumes 1000 watts/kg for his "39 days to Mars" figure. He expects to do this with solar panels (current state-of-the-art solar panels can produce ~300 watts/kg near Earth). I definitely think that VASIMR requires powerful nuclear reactors, not solar panels. Solar panels have some very significant scale problems; there are diminishing returns when it comes to power density, the bigger they get. With nuclear reactors it's the other way around: the bigger a nuclear reactor gets, the more mass-efficient it is.

I'll do that now, thank you! What I could do with this texture is, I could possibly set up texture switching (maybe using that B9 texture plugin) - but that would add an additional dependency, which is not so good. Another option is, I could use this texture to add a whole new part. I've been considering the possibility of configuring polonium RTGs. Polonium has astonishing power density: 140 watts per gram, as opposed to the 0.54 watts per gram that Plutonium can offer. There are two catches to this: first, polonium has a half-life of 138 days, as opposed to 87.7 years for plutonium. A half-life like that is much shorter than a voyage to the outer planets (if you play vanilla KSP, it doesn't have to be - but I really love playing with a 10x scaled KSP, as per RealSolarSystem). Second, a very powerful RTG core would require a commensurate increase in thermal radiators. The Korda reactors have configurations that I came up with after reading about the Topaz-I and BES-5 reactors, and the built-in radiators, like the louvers on the Iris-I and Iris-II I have assumed to be advanced carbon fiber. The plutonium cores in the coin-shaped RTGs could be bigger, but the radiator "real estate" is already being stretched to the limit. So, the realistic effect of replacing the core with a polonium one would be only a slight reduction in part mass and a slight increase in part electrical generation, as well as an unacceptably short core half-life. Additionally: Korda is here! Excellent! I love how the new reactor looks, too. Beautiful work!

Done as well. I'm hoping @korda will actually turn up in this thread - I'll contact him. He would have some development renders to show. As it stands, this add-on will focus on nuclear power and electric propulsion systems.

You're right! How silly of me to forget the license. I'll fix that right away.

Hi there. I'll cut straight to the chase and link you to an imgur gallery. Do you remember the Korda RTG parts add-on? If you don't, that's even better, because you get to see them for the first time. This is the revival of that add-on! I came back to KSP after a long hiatus, and started looking for all the various mods I made extensive use of, ages ago. Much to my chagrin, there was no way at all to find a download link to Korda's excellent RTG mod. It had entirely disappeared. So, I dug up my old copy of it, fixed the attachment nodes, and then went about trying to contact @korda in an effort to get his approval to revive the mod. Much to my surprise, he responded almost immediately by e-mail, and granted me permission to post a revived version, with significantly altered config files, and even some alterations to the part textures (as veterans will notice from the gallery). But that's not all. He's working on new parts, and I volunteered to work together with him to bring these parts to KSP. Here's a link to the Spacedock download. Current version: v1.1. Two more reactors have been added, parts have been balanced for cost. This is an incremental update - simply overwrite the existing one! The current iteration of this add-on makes use of the Near Future Electrical plugin by @Nertea. It won't work otherwise. The plugin is not included - please download it separately (it's a fantastic mod and you should use it)! I should be able to write ModuleManager configs that make these reactors function even without his plugin, but future iterations will almost certainly make much more extensive use of that plugin, because spacecraft thermal control is cool and fun.* Additionally, the backend part names have been unchanged from the original. This means that tech tree mods will correctly reference these parts, despite their new UI names. This is my first time posting an add-on to KSP. If there are any policies that I have not observed, please point them out and I'll do my best. Note: I define 1 ElectricCharge as 100 watts, not 1 kilowatt. Thus, 1ec/second is 100 joules, and not 1 kilojoule. This might cause confusion. Rest assured, the power values of these reactors are nicely balanced with stock, Near Future, and other mods. There's just some disagreement as to what the units should be called. LICENSE: This add-on is being distributed under the CC-BY-NC-SA license. * Definition of "cool and fun" may be subjective

I've come back to KSP after a multiple-month hiatus. Very cool additions to the mod, especially the science and command modules, can't wait to try them! By the way, I'm reworking my earlier engine configs for RealFuels, and there's some new content there - I've changed the propellants used to be appropriate for pressurized fuel systems. I'll see if I can figure out propellant switching (there's something really cool I want to implement), but either way, there should be an update soon.

That much is easy enough to figure out, but I was specifically wondering how to set it up in such a way that only the LV-1 model/texture are involved. There's a lot more content in the entire part revamp mod, which might be unnecessary for someone who just wants to overhaul those small engines. I'm guessing the texture for the new model is bundled together in the same .mbm as something else - that's quite efficient and commendable.

This mod has tremendous potential, I'll definitely keep my eye on it. I use Procedural Parts extensively - in fact, I've deleted nearly all vanilla tanks from my game. There have been many times in the past when I wanted to have an elliptical spaceplane body, or an airship envelope of a specific shape, but that was all but impossible. I'm surprised the mod hasn't had more attention - but then again, these things take some time to catch on.

I have a question! I love these models; I also use Alchemy Technologies which has a number of different-sized engines using the LV-1 engine model from Squad. I want to try Ven's superior model instead. I've got the model replaced successfully, but cannot figure out what the .mbm texture dependency for it is; it doesn't load a texture ingame. In exchange for this information, I could cross-post a guide and a ModuleManager config in the Alchemy Technologies thread. By the way, I'm the same guy who wrote RealFuels configs for those probe-sized engines some time ago. In any case, keep up the fantastic work, these parts (especially the various engines!) deserve their own parts set, I'd say!

This seems pretty much verbatim what RealFuels does. Would you go into more detail as to the comparative advantages this has with RealFuels?

I definitely hope it will. ORS is perfect for something of the sort. Don't forget, there are mods that use other gaseous fuels too: Near Future has hydrogen and argon as well as xenon (and the atmosphere of a gas giant is almost entirely hydrogen!), and there's also gaseous NTR fuels in RealFuels (methane, ammonia, etc; plenty of those should be in some of the Kerbol system atmospheres, like Eve for instance).

Really? That's fantastic, then! I haven't tried it yet!