SchroedingersHat

start of a config for realfuels: https://drive.google.com/file/d/0B8Z4f0VPlFhzYU1ndVRITGgySG8/view?usp=sharing

Looks consistent with everything else. I approve. Note that I may not be an entirely representative sample as I play stockalike configs/normal sized kerbin, and have slightly mixed feelings about the low densities and masses of everything in realfuels. Getting some rockets up seems a bit on the easy side, but I also like the consistent/coherent masses/densities of things so I don't want to change it -- maybe I'll just lower the Isp another smidge.

They are much heavier than cryogenic or unpressurized tanks, but (once they get over a very small size) they seem to have mass ratios on the order of 8:1 or higher Another example from a satellite http://thebulletin.org/sites/default/files_legacy_files/NASA_White_Paper.pdf 1000lb of hydrazine and 100lb dry. Bearing in mind that these are modern-alloy, non-structural tanks, a mass ratio of 5-8 to 1 seems about right (like a stock LFO tank) -- even the stock mass ratio would make it a viable choice. As it is, there's this weird situation where servicemodule tanks are an excellent choice for a main propellant, and RCS tanks are useless. As an aside: How does one get RCS thrusters to use other propellants? I only just noticed that this is (allegedly) a feature of realfuels, but I cannot seem to get it to work. Is there an example config somewhere?

Is it just me, or does the basemass for RCS tanks seem a little off? Example: A long RCS tank weighs 0.83t when full and 0.23 when empty for a ratio of around 3.6 (even worse than the stock ratios). This improves slightly with Hydrazine, but not by much. Real (modern) tanks range from about 4.5 for something tiny (http://cs.astrium.eads.net/sp/spacecraft-propulsion/propellant-tanks/39-litre-hydrazine-bladder-tank.html) to 9 for something about as big as the stratus V (http://cs.astrium.eads.net/sp/spacecraft-propulsion/propellant-tanks/177-litre-hydrazine-propellant-tank.html) Couldn't find a source anything larger that wasn't composite at the same pressure (although slightly lower pressure bi-propellant tanks have ratios up to 30 or so). They're also way off of the mass ratio of any part of the servicemodule type. My solution was to reduce the RCS tank empty weight by a factor of 3, and increase the weight of the servicemodule empty weight by a factor of 3 so they are closer. I do like to play with the same configs as everyone else though, so any thoughts?

My point was that it seems like there should be some kind of limit to the receiver, perfectly understandable if this isn't in the mod (it's already so huge and complex) but still yields odd results when abused and this was enough to make me question whether it was intended or some bug/interaction between mods. A test using my setup with a single power plant to illustrate: I have a single 8GW power station, beaming to a 1.25m receiver. To confirm that it is indeed using most of the power: This nets 1800kN of thrust at a vacuum ISP of 519. p = mV or thrust = dm/dt * V where V is exhaust velocity. This means dm/dt is 1.8 * 10^6 / (9.8*519) ~ 350kg/s. E = 1/2 * m * V^2 -> power = 1/2 dm/dt * V^2 = 175 * (519*9.8)^2 ~ 4.5GW Thus my engine is producing about 4.5GW I have no idea about real world efficiencies of a process like this, but they're usually not 100%. If we assume a fairly generous 90% of the heat leaves in the fuel, it means that the 1t, 1.5m^2 thermal receiver is somehow dealing with 450MW through radiation and other means. If we assume radiation (again somewhat unrealistic, as you could dump it in the liquid hydrogen, but still demonstrative) it would have to be at over 8000K and wouldn't be a solid anymore. There's also the issue of Jeb sitting less than a metre away from an 8GW microwave beam and being perfectly fine (but then again, he's Jeb, so he would be). I reiterate that I'm not complaining, it was just a behavior that was far enough from my understanding of what would be plausible in a near future setting that I wanted to confirm it wasn't a bug or unintentional exploit.

I'm getting some odd behaviors or bugs (possibly interactions with realfuels, but I can't seem to find the relevant configs that cause these two mods to work together). Firstly, the vista always consumes 101.80 LiquidH2 per second no matter the throttle setting. I gather from the fluff that it is meant to consume constant power, D and T, but H2 should depend on throttle setting, the net result is it's merely an okay engine, a bit better than the chemical ones but that's about it. Secondly, thermal rocket + ground based nuclear plant + keosynchronous relay is giving me obscene thrusts for a thermal rocket engine. The 0.625m engine on the small thermal receiver is producing 1600kN. Is a max power a feature still to come or is my install bugged?

I think that, if anything, the monoprop or other hypergolic engines should have a higher TWR than ignited engines on account of simplicity -- although one has to account for the fact that most of the KSP engines have poorer TWR than real world ones. Matching them to the LV-48 seems about right though.

One thought about an alternate/additional antimatter collection method: Make it manufactured rather than gathered and require gratuitous amounts of energy. This will make for some awesome low orbit solar collection arrays.

It does help a lot for people trying to use multiple mods. Also I think I saw someone mention they'd done a modulemanager version of your configs over in the FAR thread at some point. I can't seem to find it at present, but if anyone else reading this knows of it, perhaps the person who did it would be amenable to you building on that to save some work.

This mod keeps getting more and more awesome. Have you thought of adding doors to the fuselage? Or doing something like this for a reusable payload faring?It would probably have to eliminate the ability to surface attach things (unless you used or recreated mumechlib)

I gather the intent is for H2/LOX to be more useful for upper stages. The reduced mass (and improved thrust and therefore fewer engines) of a H2 upper stage makes your first (liquid fuel) stage a lot lighter. I agree that the H2 tanks are somewhat absurdly heavy, but I also note that all KSP tanks and structural components are. I think my preference for how this is to be resolved would be for the non-cryogenic tanks to have a much higher boil off rate and be similar weight to the other tanks (for LOX) or even somewhat lighter (for H2). Also some kind of cube-squared benefit to larger tanks (you spend a much smaller mass on insulation per-volume on large tanks) would be nice, but as I don't have the skills/motivation to program it myself I can merely suggest it and hope that ialdabaoth implements it.

Both of those are in mechjeb, and separately as kerbal engineer (which does a few other things, too) and I can't remember the name of the separate node editor. That said, more variety never hurts.

Wow, looks fantastic. Re. poly count, 6600 sounds completely fine from my brief fiddling and looking at other models that work well. You'll want to keep the poly count on the colliders much lower, though (notice how the B9 stuff has straight lines and polygonal shapes where possible when there is an internal cargo bay). The RCS stuff requires setting up some empty transforms where you want the thrust, IIRC, but is quite doable. Re. Making it fly, I'd just make the model (I think the origin of your model will be at the CoM/CoL, again not sure) then use the masses as a degree of freedom to get it airworthy (move mass from one part to another until CoM is right on top of CoL with a full fuel tank and a small payload, then it should be almost stable when full and you'll just be able to keep the nose up when empty). One thing to note is the body won't produce lift correctly, so you may have to do something like make the wings fit in under the body further.

Things to try: Bring two things up and dock in orbit, or make things you can undock and rearrange in orbit, install novapunch for some massive tanks/engines and use procedural farings to make something even bigger than that (8m is doable). Put tail fins, or for larger rockets full sized wings, with control surfaces on the bottom end to stabilize. Install realfuels and use a H2+LOX first/second stage, then store the LOX at the top end of the stage to move your COM up -- If it looks like a dart, and balances like a dart, it'll fly like a dart. Quantum struts may be needed to stabilize it.

What FAR is doing is inherently fairly performance intensive, and frankly I'm amazed at how little it impacts performance -- especially as it is a plugin written in a high level language. Once your craft are completely out of atmosphere it shouldn't be doing as many calculations and should not impact performance as much.

Maybe an inconsistency with which standard gravity is used for what? I seem to recall that KSP doesn't use the real-world standard gravity for some/all of its calculations. See if the ratio 9.81/9.82 is meaningful in the differences.

[quote name=sumghai;537587 ASIDE: It seems that Innsewerants hasn't been on the forums since 5 June 2013. Now' date=' if only he had made the source of his X4r1 available with a licence, one of us could in theory look into this...[/quote'] There is source for earlier versions kicking around. Does anyone know what the licence was?

Afaik it's png textures that don't have the memory bug. tga's are meant to be well optimized, but there is something wrong with the way the current version of ksp/unity handles them (don't take my word on it though if you have a good source, I can't remember the threads it was discussed in so I'm working mostly from memory and what I've seen in my ksp folder lately)

As far as I know, MMH and UDMH are usually added to make it slightly safer, improve cooling, and will (marginally) decrease density and Isp of the fuel. None of these things sound very Kerbal and the heat system isn't that complicated (yet?) so my thought would be to just have 'hydrazine' and leave it at that.

It does nothing and you can't get rid of it. The thing it is modelling is your nuclear engine has a big lump of uranium/plutonium/whatever; as it decays some of it turns into other elements/isotopes and is no longer fissile (but is still largely part of the same lump of mostly-metal). Once it is all gone the engine would require reassembly with new fuel. I wouldn't worry about it too much as you're unlikely to run out. If you are going to be implementing a system for altering thrust, might I request the addition of a velocity/pressure 2d curve for jet engines? Something like: thrustCurve { pKey = 1 0.1 0.01 0 // Pressures as fractions of sea level pressure on Kerbin vkey = 0 1 0.5 0.2 0.1 // A velocity followed by the thrust multiplier at each of the pressures listed vkey = 500 0.67 0.3 0.1 0.05 // As above vkey = 550 0.44 0.1 0.04 0.01 vkey = 605 0 0 0 0 } Then the same for Isp The alternative would be some kind of 2d table (much easier to read/edit) but I don't know if that's possible. Either way, I believe making max thrust a function of pressure and velocity and Isp an independant function of pressure and velocity should allow for much more realistic air-breathing engines (as opposed to the current state where Isp is a function of pressure and velocity (because the velocitycurve modifies thrust and not fuel use) and thrust is a function of velocity). Then I can do some reading and fiddle with nasa engine sim and learn what parameters to actually set (or Ferram or Taverius or someone can use their existing knowledge to do it much more efficiently)

Source I can't seem to reconcile this with anything Edit: Never mind, you were talking about modularfueltanks not stock

@iadabaoth I've been fiddling with adding some life support resources and I figured out that a utilization > 1 can be used for things such as Oxygen which I want uncompressed in habitable pods and compressed in tanks (without adding extra resources and converters). Might I request that this behavior either remain and not wind up being fixed or be formalized with some kind of compressionratio parameter in the event that it is removed?

Oh, I get it now. By burning pure horizontal you can accelerate down quicker than you would otherwise (even after steering losses) and spend less time (as gravity loss is a pure function of time and horizontal speed) accumulating gravity loss. I'm guessing then that the ideal is going to be somewhere in between and would depend on the altitude which you decircularized from.

Firstly is that TWR standard gravity or gravity on the relevant body? Isn't a zero lift turn still going to be more efficient? I usually go for a zero lift almost-suicide burn. Set my periapsis at a bit past my landing spot then wait a bit until almost 0.5at^2= distance to landing spot and burn pure retrograde.

Or posts 1 through 249, I think most of them mention it either by asking the question or responding to someone who did.