Starman4308

Nein. It should be asked in the RealFuels thread, because it is a RealFuels question. There are probably other storable fuels out there. You might just barely be able to get away with kerosene/LOX (LOX boils at -183, ambient temperature in space is about -200C from what I've seen), kerosene/HTP should work, and liquid methane and ammonia have high boiling points. There are also cooling fins, although I haven't used them and am not sure how they work. I personally use MMH/NTO and Aerozine 50/NTO mixes for anything expected to be restarted after more than a week in space, though I might dabble in liquid methane/ammonia once I get to nuclear thermal rockets (the LV-N and similar).

Are you possibly using RealFuels? Liquid hydrogen, liquid oxygen, liquid ammonia, liquid methane, and other cryogenic fuels will experience boiloff if ambient temperature exceeds their boiling point. The three fuel mixes I know of offhand which are 100% storable are Aerozine 50/NTO, MMH/NTO, and hydrazine. Also, pressurized tanks aren't going to reduce boiloff; cryogenic tanks (the Jumbo-64 or cryogenic procedural tanks) will. RSS itself does not touch fuels, engines, etc, it just scales up planets.

Ah, thanks: I'd forgotten about that, because I never needed such precision before. In any event, my best guess is ~28-30L, by playing with a procedural tank until it looked right. Doing a bit of research into fuel cells, using the space shuttle fuel cells as my reference. Either I'm missing something, or the Space Shuttle fuel cells were fuel-inefficient, achieving only ~14.5% efficiency, which does not square with modern PEM fuel cells, which get 50-60% efficiency (more for industrial fuel cells which utilize the waste heat). I'm not 100% sure how I want to implement the fuel; I think the best way to go about it would be to use the TAC: Life Support resources and implement a Hydrogen resource; that avoids problems like "how do I create a tank which won't boil off LH2/LOX". I imagine there'd be some way to have in-house H2/O2/water resources over-ridden if TAC:LS is installed? Fuel cellshttp://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/eps/pwrplants.html Space shuttle fuel cells: 14"x15"x40", 255 lbs (0.3556 x 0.381 x 1.016 m, total of 0.1377 m^3 = 137.7 L, mass of 115.67 kg) Provides 7 kW continuous, 12 kW peak (60.5 W/kg continuous) Takes "only a few minutes" to flood the fuel cell At liftoff, fuel cells produce 220 A using 4 lbs/hr LOX and 0.6 lbs/hr LH2, probably ~30 V. Produced 11 kg/h of water at 7 kW (http://www.braeunig.us/space/specs/orbiter.htm and http://science.howstuffworks.com/space-shuttle.htm/printable) http://spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/eps/storage.html The oxygen tanks were double-walled (33.43" interior, 36.7" exterior diameter), with a volume of 11.2 ft^3 and 781 lbs of O2. Dry mass 201 lbs, storage temperature -285F The H2 tanks were 41.51" interior, 45.5" exterior, storing 21.39 ft^3, for 92 lbs LH2 (216 lbs dry). Initial temperature -420F Up to five tank pairs/mission CRC Handbook of Chemistry and Physics lists 141.8 MJ/kg energy capacity of hydrogen, and 286 kJ/mol (roughly square with each other) Calculations Produced 25200 kJ/hr 11 kg/h water would be 9.78 kg/hr LOX and 1.22 kg/hr LH2. Theoretical generation: 173.31 MJ/hr. Approximate efficiency is 14.54%. Either space shuttle fuel cells were terrible, or I'm missing something. Hybrid cars using PEM cells get ~50-60% efficiency

Wrote up a RealFuels config for NecroBones's fuel tanks, duly assisted by the volume of a sphere, as well as a tweak to get . I also almost finished my 6.4x Apollo-like mission. I got to the Mun, planted my flag, took off, switched to the command module to check something, switched back to the lander for rendezvous, watched the Kraken smash it to the ground in three seconds flat... and I had no save file since before I'd even launched the mission. So very frustrating.

Pull request sent! The only decision I made not mentioned in the pull request was the kitchen-sink decoupler, which combines a 1000L RCS tank with a 2.5m decoupler and 2.5-3.75m adapter. That, I gave a base mass of 0.55t (0.4t for the decoupler, 0.15t for structural element). EDIT: To remove any possible confusion, this did not include the ion engine tweak, which should not be in RF proper, and is not complete yet. It's just the tanks.

You simply don't have enough ion engines. What is this "part count limitation" that you speak of? For myself, I don't have any huge examples, but my latest Apollo-style mission used the S-IVB equivalent to achieve low Munar orbit before giving up the ghost and switching to the service module's engine.

Doesn't help that stock engines have hilariously narrow gimbal ranges. RCS Build Aid could be used to help visualize CoM/CoT and net torque both full and dry, but in general I steer away from space shuttles due to "Why did NASA ever think this was a good idea". Horizontally-launched SSTOs work perfectly well in stock, and it shouldn't be too difficult to get significant rocket recovery in RSS (possibly using StageRecovery for first stages).

Hohmann transfer is what you're looking for. One thing which wasn't well-explained is that, by default, MechJeb will transfer you straight at the target, which is useful for rendezvous, but not useful for lunar injection, because your target orbit will send you plummeting straight for the center of the Mun. You will need to edit the maneuver node: a low-velocity, later burn will get you an efficient cis-lunar insertion, while an earlier, more powerful burn will get you a trans-lunar insertion. A special case of trans-lunar insertion is the free-return trajectory, which will send you on a figure-8 around the Mun and back into Kerbin's atmosphere; the first Apollo missions did this, so that if the Service Module's engine didn't ignite, it would simply return to Earth. It also makes a wonderfully efficient lunar flyby trajectory. Regardless of whether or not you use Mechjeb to set up the initial transfer, I would still recommend playing with the maneuver node to see what effects various modifications to the burn have on your trajectory, and try to figure out why those happen.

I assure you, put enough vertical boosters on something, and it will fly. It might not fly long, but it will fly. If you want help figuring out if it will fly long, I would strongly suggest pressing spacebar.

I've only been playing since 0.24.2, but I am 95% sure command pods have never passively drained electricity. Anybody who has had manned missions run out of juice is either using a probe core, lights, a mod like TAC: Life Support, is using SAS during physical time warp, or otherwise has some other source of power drain going. EDIT: I can't read (in reference to Overfloater's post). Still: command pods will not drain electricity in non-physical time warp, because SAS cannot function, and (unless modded) has no passive drain associated with it.

I suppose maybe it's bigger than it looks, but here's an image for comparison. The procedural tank is, again, 46L. I'm pretty sure the appropriate scaling would be <=40L*; the cylindrical stack tank is 70L, and that very neatly coincides with the stock volumes of 400/700 xenon. In any event, should I kick any further MRS-RF development questions to a separate thread? I wouldn't want to clog up RF or Raptor's thread with things not related to RF or RF-stockalike engines as they currently are. *On playing with the perspective a bit, the 46L tank is much too wide for valid comparison. I can't quite get the sizes to line up (the xenon tank a bit wider than 0.25m, and a bit longer than 0.5m), but it might be closer to ~25L. Unfortunately, I don't know what tools could be used to measure the volume accurately.

Well, I'll pick it up tomorrow/whenever I have time. I'm pretty sure I have the right way to rescale electricity consumption: take the electricity consumption per kilogram (180 E/kg for stock), multiply by the density of xenon gas, and then multiply by whatever scaling factor you want: that ratio should be 0.00106092 for a stock rescale. I also remembered to tweak mass to ~1/3 stock, roughly in line with the other engines. To the best of my understanding, the absolute ratios can be arbitrary, but the relative ratios determine how much gets spent (for example, you could have 50 LF + 50 O, or 0.5 LF + 0.5 O, and they would be the same). Problem is I need to figure out how to properly write the config file so it modifies an existing propellant instead of adding one; I had the amusing sight of adding a 50% Xenon/50% Xenon mix to the fuel tanks when I tested this. @MODULE[ModuleEngines] { @atmosphereCurve { @key,0 = 0 4200 @key,1 = 1 200 } PROPELLANT { name = ElectricCharge ratio = 0.00106092 // Calculated as such: stock PB-ION consumes 180 E/kg xenon, mutliplied by density of RF xenon. } PROPELLANT { name = XenonGas ratio = 0.1 // Just realized I might want to set this to 1.0, because the above electricity ratio is E/unit, not E/0.1 unit like stock. } }

I'm pretty sure Near Future Propulsion has a bunch of configs for ions, so I can look there to see how to tweak electricity usage. I don't know if you want me to tweak the ions past "get them back to stock-ish", which should require only tweaking thrust/fuel flow and electricity/xenon ratio. If it were my own config, I'd probably take a crowbar to the thing, reduce Isp to 1800s, decrease thrust a bit (probably to 1 or 1.5 kN), and set the electricity usage to ~3-4 Gigantors' worth. I know Nathan pointed out that, for 2 kN, it really should require 12,000 Gigantors, but I think most reasonable people will agree that we shouldn't be forcing players to use 12,000 Gigantors. In the meantime, I'll try and find if there are any part packs with larger RTGs, because if you do want to go through the route of increasing electricity consumption, you'd need a forest of stock RTGs to keep up. EDIT: By the way: much thanks for the patience and help. First time writing any mod, even if it's just a config file.

Well then that makes NecroBones's xenon tanks really simple, because they are spheres. The stock xenon tanks are, upon a closer look, mostly correct, although the radial tank seems to be made mostly out of hyperspace (contains 200L; a procedural tank of slightly larger size is 46L). If you're interested, here's the project so far, although I've only got basic functionality going yet. His fuel cells are probably something which should be incorporated into the engine configs, because they're dependent on what electricity unit is being used (the stock Who-Knows-What-This-Is unit or the RO-style kJ). For the stock unit, I'll probably assume for now that LF/O is RP-1/LOX, and scale the chemical energy of that to LH2/LOX. I'm not sure if other fuel types are used for space vehicles, but LH2/LOX has an advantage in that, with a bit of coding work, it should be possible to store the resulting water, and then see if I can borrow TAC:LS's water splitter to regenerate the fuel. EDIT: Change to repo location

Draft 1 with all the easy bits are done: take all the LF tanks, multiply LF+O+MP by 5, give them the appropriate tank type. I almost missed your decoupler/monopropellant/kitchen sink hybrid, but that got turned into a monopropellant tank. The remaining things: Determine if RF does anything with intake air Handle the fuel cells. Determining how to scale it's going to be fun: there are no delta-G values available for the combustion of these "liquid fuel" and "oxidizer" substances, though draft 1 might just be assuming they're equivalent to RP-1/LOX. Potentially tweak the dry masses and solid-fuel capacities of the launch escape system and Flingatrons to be more in line with other RF SRMs. EDIT: Xenon tanks scaled, being 110 and 880L capacity (assumed spherical and 86% volume utilization, rounded up a bit). I don't think RF does anything with intake air, but I wouldn't hold my breath. EDIT #2: Pull request sent to Nathan. You may or may not be able to view the repo (GitHub seems to think I'm a robot); if you're desperate for the tank configs, grab the config from there. The "dev" version also includes a little tweak to bring ion engine electrical consumption back in line with stock. One little thing I did for giggles was to turn the mini-orange tank into a cryogenic tank, much like the default RF config for the Jumbo-64 tank. EDIT #3: The repo has changed to here due to silliness with GitHub rules (why they prefer me to have a shell organization instead of a second account, I will never know).

If you are using a vessel which only has manned command pods, it is possible to have 0 electrical consumption. If you are using a probe core or other electricity-leaking part, though, I don't know what's going on; I've always had electricity deplete through timewarp on the dark side of moons, though that might be a consequence of one of the mods I use.

It doesn't: the effects are a result of RF scaling the xenon, and Raptor's config not scaling the electricity/xenon ratio, because he doesn't touch it. I'm just figuring I'll try to tone it back down: it presently consumes the equivalent of 8.2 Gigantor XLs of electricity, due to a calculation which has to do with scaling issues and no deliberate thought on anybody's part. EDIT: For all I know, 8.2 Gigantors might be 100x less than what real-world ion engines would need for 2 kN of thrust. I'm cognizant, however, of that ion engines really do need to be out-of-line with real-world performance to not make them boring to use (though 4200s Isp is a little crazy).

There might be some aesthetic similarities here and there, but KSP engines are, as a rule, far heavier and lower-thrust than realistic engines. Isp is a complicated bag of kittens, because that depends on what fuel type you're using. They'd make hideously inefficient LH2/LOX engines, but they're better than any other fuel mix I see (better than RP-1/LOX, Aerozine 50/NTO, etc). If you're interested in making KSP replicas of real rockets, I strongly suggest Realism Overhaul, which comes prepackaged with many real engines, as well as realistic fuel tanks. Those 9:1 full:dry KSP fuel tanks are more or less lead weights compared to real tanks: the Space Shuttle fuel tank was about 96% LH2/LOX by mass, for example.

If it were to be sent to the ISS, you could include a heatshield with the payload, and have ISS personnel fix the heatshield onto the bottom before sending it home. I suppose one might be able to make a robotic system to do the same, but it's a complicated procedure to take something from the top and secure it to the bottom.

Hey Nathan, I've been writing up a RF config for NecroBones's Modular Rocket Systems*, and I noticed a few oddities with the ion engines/tanks along the way. The small radial xenon tank has a capacity of 200L, and the cylindrical stack tank has a capacity of 70L: empty masses are unchanged from stock. NecroBones also has some xenon tanks, so it would be helpful to know how to scale xenon volumes. It'll also help with the ion engine config: I'm pretty sure what happens with the PB-ION as-is in Raptor's config is that it appropriately adjusts the xenon consumption, but doesn't touch the ratio of electricity to xenon, and as a result consumes a hideous amount of electricity. I figure that, for now, I'll try to wrangle it to return to stock performance, and let Raptor decide if he wants to nerf it down to something less outrageously unrealistic. Aside from all that, the only goofiness I see is that procedural tanks let you store outrageous amounts of electric charge when using stock electricity units, and there's a simple fix to that: don't use procedural tanks to store electricity. *Is the standard procedure just to send pull requests on Github when finished? EDIT: For clarifications, Raptor's config does not presently touch the ion engines: this was me saying "knowing the xenon scaling ratio will help me figure out how to whack the electricity/xenon ratio back in line with whatever Raptor wants".

Hey NecroBones, do you mind if I try writing up a RealFuels config for your fuel tanks and sending it Nathan's way, so it can be incorporated into the next RealFuels version? Also, if I do get the green light: would you have any preference for tank types? I figure the jet fuel tanks should get the Fuselage type, most tanks the Default type, but that little probe fuel tank, I'm not sure on whether to set it to Default or ServiceModule.

You could try imitating the logic from the Trajectories mod. As I understand, it's likely to involve a lot of numerical integration of differential equations, and is not going to be simple to write.

Well, if you really miss wobbly rockets, you can always make a rocket out of 256 10mm-thick fuel tanks from Procedural Parts, and watch its best Slinky impression. For myself: wobbly rockets are evil, and I wish there were better ways to keep thin payloads stable on the top of rockets.

Please look at the last posting date before you post. This question was answered a year ago, and you are not helping anybody. If you're unaware, posting in old threads is called "necroposting" and is generally frowned upon unless you have something important to add.

Bottom of RealSolarSystemSettings.cfg are the warp rates. Change them back to stock.