Northstar1989

Also, it's not specified on the original list, but the point we would be running the Fischer-Tropsch process to is to manufacture RP-1, which is comprised almost entirely of 12-Carbon alkanes (C12H26). This is the stoichiometric ratio we would be using to determine the mass-fractions of CO vs. H2. http://en.wikipedia.org/wiki/RP-1 Regards, Northstar - - - Updated - - - AWESOME! What do these entries in the changelog mean? In particular, did you make it so the interstellar fuel tanks can no longer hold HydroLOX (if so, why?) or just re-order the fuel-modes for the interstellar tanks? Also, which "merged resource changes" did you remove from the RealFuelsFix file? What exactly do you mean by that term? Regards, Northstar

Yeah- but the RealFuelsFix hasn't yet been updated to allow the RealFuels tanks to hold the new, re-named Nitrogen resource for KSP-Interstellar (since RealFuels has no native use for cryogenic Nitrogen- and its only Nitrogen is NitrogenGas for RCS- it doesn't have any native tanks for LqdNitrogen of its own...) I also posted new lines of code to add to the file to allow Nitrogen and CO2 to be stored in ServiceModule and standard (Default and Balloon) fuel-tank types. In hindsight, the "Fuselage" tank-type is functionally identical to a ServiceModule tank-type, except with higher impact-resistance and an even heavier frame the tanks fit into, and should also be added as a valid RealFuels tank-type to hold Nitrogen. Thus the code to add Nitrogen tanks to "ServiceModule" frames should also apply to adding the same tanks to "Fuselage" frames, as follows: @TANK_DEFINITION[ServiceModule,Fuselage]:NEEDS[RealFuels]:FOR[WarpPlugin] { TANK //Add LiquidCO2 to ServiceModule and Fuselage tanks. { name = LiquidCO2 mass = 0.00008 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -56 loss_rate = 0.000000000006 note = (has insulation, pressurized) } TANK //Add LiquidNitrogen to ServiceModule and Fuselage tanks. Values are based off of LqdOxygen. { name = LqdNitrogen mass = 0.00008 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -183 loss_rate = 0.00000000002 note = (has insulation, pressurized) } } FreeThinker, please add these tank-definitions (from this post and my previous post) to the next update as soon as possible, and raise the starting-points for the decomposition-curves of Water and CO2 to 2200 and 5000 K, respectively. Regards, Northstar - - - Updated - - - That was a typo, actually. I meant to say "Hydrogen" not Oxygen. The only sense Nitrogen can be "burned" with Oxygen is by using it in a ISRU Refinery to make N2O4, which is the oxidizer normally used with hypergolic fuels (MMH and UDMH- which are both Hydrazine with extra methyl groups tacked on, see my previous posts on why the reactions to make both should be added to our ISRU processes...) However, Oxygen *can* be used as an afterburner with either Ammonia or Hydrazine, to achieve a LANTR-effect (the same as is used to augment the thrust of Hydrogen with HydroLOX-LANTR, but with different Thrust and ISP...) by combusting Oxygen injected at the exhaust-nozzle with H2 in the exhaust-gasses from an Ammonia or Hydrazine Thermal Rocket (both of which produce a combination of Nitrogen and Hydrogen gas as exhaust gasses...) As I discussed before, the best system for code like that would be an adoption of Regolith. That has some tricky issues with drawing directly on atmospheric resources, however none of the new ISRU reactions except Solid Oxide CO2-Electrolysis and Methane Pyrolysis (which requires a source of hot CO2 to clear out the reaction chamber of the graphite produced) actually rely directly on any atmospheric resources... Still, although expanding the current system may be error-prone, I think it's the only way we could reasonably hammer out the new ISRU reactions before next Monday- unless you were able to draw RoverDude in to work with you on using Regolith-code (he doesn't like me very much, and we probably wouldn't work well together). So, I would suggest just hammering out the code with the existing system so we can get it done before 1.0 already! Too complicated. I don't have the time for that kind of thing anymore- as is I'm pushing the limited time I have available between my two new jobs (and one existing job) which are just starting up to write everything you've seen so far... Can we please just get to the ISRU reactions already? I really, really, REALLY want to get those out before the 1.0 release on Monday! Regards, Northstar - - - Updated - - - The ISRU Reactions may seem intimidating, but can actually be added quite quickly. After all, we have all the required resources already implemented (or part of RealFuels- in which cases we need only borrow the RealFuels definitions ad add them to our configs), I can easily provide you with the mass-fractions of each reactant and product for the reaction, and the relevant rates and power-requirements can be eyeballed (although I will provide you with information on where we need to balance them relative to the existing reactions, and provide some estimates for good numbers to use in each case). We can EASILY knock this out in a couple days of focused effort. The list, again: http://forum.kerbalspaceprogram.com/threads/111159-WIP-0-90-KSP-Interstellar-Extended-0-9-3-Updated-21-4-2015?p=1837855&viewfull=1#post1837855 Regards, Northstar

Another thing I noticed: - The boiloff rate for LqdCO2 in RealFuels (as set by RealFuelsFix) is completely off. Whoever wrote those configs based the CO2 loss-rate off the *uninsulated* loss-rate for Liquid Oxygen, which would explain why I've seen my Carbon Dioxide boil off far too fast... (Liquid CO2 boils off MUCH more slowly than Liquid Oxygen, *not* faster...) A BETTER config for LqdCO2 (one with a loss-rate that is more accurate- and thus helps to balance CO2, which has few advantages as a propellant besides being easily stored...) is the following: TANK //Add LiquidCO2 to Cryogenic tanks. { name = LiquidCO2 mass = 0.00006 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -56 loss_rate = 0.000000000006 note = (has insulation, pressurized) } The new loss-rate is slightly less than the rate for insulated Ammonia tanks at 1 atm (not "pressurized" in RelaFuels)- Ammonia at 1 atm has a slightly lower boiling-point than CO2 at 5-6 atm (I actually copy-pasted the rate for Ammonia and replaced the 7 with a 6...) The loss-rates decrease exponentially with higher boiling temperatures and molecular weights in both real-life and RealFuels... (that is, Ammonia has a boiling-point a bit more than double that of LqdOxygen in terms of absolute temperature, but only 1/5th the loss-rate for an insulated fuel tank in RealFuels...) and the new loss-rate is based off the exponential relationship already present in RealFuels plus a slight (less than 5%) further decrease in loss-rate to reflect reduced thermal leakage into the tank (what ultimately drives all boiloff) due to having thicker tank walls (see below...) I also increased the tank-mass slightly more than 5-fold compared to unpressurized but insulated LOX (or 6-fold compared to LqdMethane), as CO2 must be kept pressurized above 5.10 atm to remain as a liquid... (this is as the tank walls must be stronger to hold the increased pressure- and thus proportionally more massive/thick...) I assume an at least 5.1-fold increase in the mass of the tank in proportion with the increased pressure... (as pressure vessels generally have walls that grow nearly in direct proportion thicker with increasing pressure-differential with the environment...) These aren't all the changes I strongly suggest be made to the RealFuelsFix file, however. CO2 and Nitrogen should also be added to RealFuels ServiceModule tank-types (unlike Cryo and BallonCryo tanks, ServiceModule tanks are ALWAYS pressurized...) with the following additional lines of config (note that the tank-masses are heavier for the ServiceModule tanks than for other tank-types, like with all the other propellants in RealFuels...) @TANK_DEFINITION[ServiceModule]:NEEDS[RealFuels]:FOR[WarpPlugin] { TANK //Add LiquidCO2 to ServiceModule tanks. { name = LiquidCO2 mass = 0.00008 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -56 loss_rate = 0.000000000006 note = (has insulation, pressurized) } TANK //Add LiquidNitrogen to ServiceModule tanks. Values are based off of LqdOxygen. { name = LqdNitrogen mass = 0.00008 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -183 loss_rate = 0.00000000002 note = (has insulation, pressurized) } } Finally, insulating Nitrogen and (especially) CO2 isn't necessarily a requirement- especially for launch stages. What tanks which don't count as "insulated" in RealFuels simulate are tanks which are only lightly-insulated. Such tanks are often actually used for cryogenic launch-stages in real life, as there is no need to keep the fuels cold for long if they'll only be in the tanks a few minutes between launch and MECO (Main-Engine Cutoff, i.e. first-stage separation for most designs...) As such, there should also be the option to store them in only lightly insulated fuel-tanks, which would make for lighter stages (but have significantly higher boiloff-rates). The following data for these tank types is based off such tanks for other cryogenic fuels, such as LOX and LH2... @TANK_DEFINITION[Default,Balloon]:NEEDS[RealFuels]:FOR[WarpPlugin] { TANK //Add LiquidCO2 to standard tanks. { name = LiquidCO2 mass = 0.000062 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -56 loss_rate = 0.000000002 note = (lacks insulation, pressurized) } TANK //Add LiquidNitrogen to standard tanks. Values are based off of LqdOxygen. { name = LqdNitrogen mass = 0.000014 utilization = 1 fillable = True amount = 0.0 maxAmount = 0.0 temperature = -183 loss_rate = 0.00000001 note = (lacks insulation) } } Note that the actual tanks themselves are HEAVIER for their fuel-capacity: but the structure they are built into is much lighter, and this more than makes up for it. Thus a LOX Balloon tank stage is always lighter than a LOX BalloonCryo tank stage of equivalent capacity, despite the LOX tank itself being heavier, due to the lighter weight of the structure it fits within... The same balance is maintained here- the increase in tank mass is less than the decrease in the mass of the structure the tanks fit into... I know I've been suggesting a lot of changes lately, but they are all VERY IMPORTANT! Please try and incorporate these changes in the next update FreeThinker. Regards, Northstar

@FreeThinker Two more things I noticed when I loaded up the game tonight and from examining the config files: -The Atmospheric Scoop now scoops "LqdNitrogen" instead of "LiquidNitrogen" but the RealFuels tanks still hold "LiquidNitrogen" (they normally don't hold either- they only hold cryogenic Nitrogen thanks to the "RealFuelsFix" file we have under resources...) The RealFuelsFix file needs to be updated so that the RealFuels tanks now hold "LqdNitrogen" instead of "LiquidNitrogen". - You REALLY need to look at the power-requirements for the interstellar "flex-tanks". Currently, according to the config, they require the same amount of electrical power for every given fuel-type, despite each fuel-type having a separate entry for power-requirement that could be easily customized. The lower the boiling-point of a propellant the higher its power-requirement should be, and vise-versa. Also, the boiling-temperatures you set for CO2 and CO are flat-out wrong. I think the error came from how you converted Celsius to Kelvin, although I really have no sure idea why your values are so far off... The CORRECT boiling-temperatures in Kelvin are: LqdCO: 81.65 K (-191.5 C) LqdCO2: 220 K (just under -53 C, assuming moderate pressurization of the CO2 to about 6 or 7 atm- which MUST ALWAYS be pressurized to at least 5.10 atm of pressure to remain as a liquid) You currently have 191.5 for Carbon Monoxide (which I can only assume came from an improper unit-conversion from -191.5 C to Kelvin...) and 194.7 for CO2 (which I have no idea where you got that number- that's FAR too cold a boiling-point for CO2...) Regards, Northstar

Also, I've said this before, but the decomposition-temperature values are still off for CO2 and Water... More appropriate values would be: CO2: 5000-7000 K (also, CO2 acts to CLEAN soot below 3200K- the temperature at which you currently have it start decomposing) Water: 2200-4200 K (currently it is 2000-4200K, but even using a Gaussian curve 2000 K is still far too low to start the curve at...) In the case of Carbon Dioxide, decomposition starts occurring at far lower temperatures, but it's not until you get around 5000 K that the decomposition-times start being measured in seconds, and not minutes or hours... Regards, Northstar

Erghh, I think I reported the wrong one. It was LqdCO2 that was duplicated (there are two identical "LqdCO2" entries as well as a "LiquidCO2" entry and a "LiquidCO2Cleaning" entry). I know combusting Hydro/LOX in the stoichiometric ratio may seem appealing, but it simply won't work in a thermal rocket. The ratio we currently use is already near the maximum LOX-injection you can have with LANTR- much more and the extra LOX fails to receive exposure to Hydrogen (due to the surface the reaction occurs along only being the inside of the rocket nozzle and necessarily incomplete-mixing) and simply sits there, likely building up as a cryogenic liquid on the inside of the rocket nozzle (the energy it takes to heat a liter of LOX is so much greater than the thermal energy stored in the small amount of exhaust that comes in contact with it that much of it will probably remain liquid) and eventually sloughing off in liquid form- producing no additional thrust whatsoever... In short, you *COULD* add more LOX to the reaction, but it would produce almost no additional thrust at all. Much better to simply carry some extra Hydrogen in pure form (with cryogenic cooling) or in the form of Ammonia (which is actually a denser storage-medium for Hydrogen than Water- and has the advantage of also producing Nitrogen, which makes an *excellent* electric propellant for final stages or a thermal propellant for landers...) The Nitrogen from Ammonia-electroylsis can not only be used to burn the surplus LOX from Water-electroylsis: it also can be saved and use as a feedstock to produce hypergolic fuels (*cough* if we ever get around to focusing on expanding ISRU) when you get somewhere like Duna where Carbon and Hydrogen are plentiful (MMH and UDMH are composed of nothing but Carbon, Hydrogen, and Nitrogen), but Nitrogen is almost nonexistent... Or barring that, Nitrogen also can be used as an RCS propellant in real life and with RealFuels installed (if you install the RealFuels "ModuleRCSFX" module...) Regards, Northstar

e-dog, I'm still hoping to see the new tech-limits I laboriously drew up implemented: http://forum.kerbalspaceprogram.com/threads/39512-0-90-Procedural-Fairings-3-11-manual-shape-controls-%28December-17%29?p=1795833&viewfull=1#post1795833 holyfeld, Regarding the term "Gesundheit", I'm afraid you didn't understand your college German class correctly if you thought "sind" is used to mean "to go" in the sense you use it. You are mis-understanding the use of predicative nouns and predicative adjectives: http://en.wikipedia.org/wiki/German_verbs#Predicative_nouns_and_predicative_adjectives In everyday usage "sind" has a meaning that more closely means "to be", as in "Der Bienen sind Insekten" (the bees are insects). Thus, "Gesundheit" means "good health" or "[to return to] good health again". I guess my high school AP German teacher really *did* know what he was talking about back in the day, although cramming 5 years of material extending all the way from the basics as far as predicative nouns and past participles and such into just 4 years (it was a special "advanced" class) made my head want to explode back then! (and my own knowledge of the subject apparently closely aligns with Wikipedia- not always good...) Regards, Northstar

OK, a few quick notes on the EnginePropellants file in the latest version: - The temperatures at which CO2 starts breaking down at a noticeable rate in a thermal rocket is still too low. It should be 5000-7000 K, not 3200-7000 K. - We need some way for CO2 to only deposit soot at very high temperatures (above 5000 K). Below 3200 K it actually tends to CLEAR soot out of the rocket (between 3200 and 5000 K it deposits it- but at a rate so slow as to not be noticeable in the timeframe of a thermal rocket...) - There are duplicate entries of some fuels. I'm not just talking alternative names of the same thing or the obsolete and new versions of some fuels- some fuels are actually listed twice with EXACTLY the same name and data (as in "LqdNitrogen" and then "LqdNitrogen" again a little later...) Gotta get to work now. Regards, Northstar

Hey guys! Sorry I've been out of the loop for a while! I've made a good bit of progress since my last update, but the screenshots had been piling up on my computer- with it becoming a more and more arduous task to upload the ever-growing pile... OK, so first of all, my Minmus Probe-Lander captured into Minmus orbit: After which I made several landings- including one that completed a contract milestone for a contract to perform seismic surveys on Minmus! (THAT was a particularly difficult precision-landing) After which my Minmus Lander ascended back to orbit and rendezvoused with my Hypergolic Tug: And then returned the whole thing to Kerbin- where I performed a propulsive landing of both the tug and lander... Of course, this wasn't all I was up to... I also launched a tanker to refuel my Munar-1 Lander: This was actually a particularly difficult launch to get right, as I was having some problems getting the right TWR on the launch and upper stages for this mission... Anyways, like almost all my launches, it involved recovery of the launch-stage: The upper stage then proceeded to rendezvous with my Munar-1 Lander, dock, and refuel the lander: The intention of this was originally to see if I couldn't land the Lander on Kerbin, but several "simulations" (reverted attempts) revealed that a Kerbin TWR of 0.9 was simply not enough to safely land a Mun Lander back on Kerbin... I was able to recover the tanker with a parachute-assisted propulsive landing, though: The two tiny parachutes were Tweakscale scaled-down variants of the stock radial parachute applied in 2x symmetry on the top of the interstage... Regards, Northstar

I'm not so sure about the "useful as a propellant" part (unless you're referring to the CO/O2 rockets I mentioned earlier- which have an ISP in the 200 second range and are only really useful as they can be refueled with nothing but the atmosphere of Duna/Mars and some electric/thermal power...), considering its molecular weight (28) makes it interchangeable with Nitrogen for Thrust/MW and ISP, but it isn't nearly as easily collected from the environment. Actually, its Thrust/MW and ISP should be almost *exactly* the same as for Nitrogen- it's a propellant with the same molecular weight and even heat capacity (29 J/mol*K) as Nitrogen, making it an essentially identical propellant. Except for its storage characteristics- Carbon Monoxide is slightly easier to store as a cryogenic liquid than Nitrogen (its boiling point is -191.5 C vs. -195.8 C for Nitrogen)- CO has absolutely no advantages over Nitrogen as a thermal rocket propellant. Even its cost is much higher (I'm getting wholesale figures no lower than $20/kg for compressed CO gas- compared to as little as $0.07/kg for compressed Nitrogen gas...) than Nitrogen... Anyways, if you wanted a resource config, it should be: RESOURCE_DEFINITION { name = LiquidCO density = 0.000790 unitCost = 0.0021 flowMode = STACK_PRIORITY_SEARCH transfer = PUMP isTweakable = True } This is based on a cost a bit less than $20/kg in 2015, with 1965-->2015 inflation taken into account, and is probably even a little over-optimistic... For a Thermal Rocket config it should be identical to Nitrogen: BASIC_NTR_PROPELLANT { name = LiquidCO guiName = Carbon Monoxide ispMultiplier = 0.3273 PROPELLANT { name = LiquidCO ratio = 1 DrawGauge = True } } Regards, Northstar

I know I sound like a broken record, but when are we going to get to THIS list of ISRU reactions? A quick recap of the list: * Sabatier with internal propellants (already implemented) * Reverse Water Gas Shift Reaction (CO2 + H2 --> CO + H2O) * Direct/Solid-Oxide CO2 Electrolysis (CO2 --> C + O2) * Fischer-Tropsch Process (CO + H2 --> CnH2n+2 + H2O) * Methane Pyrolysis (CH4 --> C + 2 H2) * REAL Anthraquinone Process (H2 + O2 --> H2O2) * Monopropellant --> Hydrazine production with RealFuels (and CORRECT chemistry: H2O2 + 2 NH3 --> N2H4 + 2 H2O) * Hypergolics Production (MMH: N2H4 + CH4 --> N2H3-CH3 + H2, UDMH: N2H3-CH3 + CH4 --> N2H2-2(CH3) + H2, NTO: N2 + O2 --> N2O4) Numbers 2-8 still haven't been implemented yet. Numbers 3 and 5 are exceptionally useful on Duna with current reactions, fuels, etc. Numbers 2 and 4 are amazing with RealFuels installed (you use the reverse Water Gas Shift Reaction to get CO and water, then react the CO and Hydrogen to get Kerosene and water...) Reaction #6 is useful without RealFuels, but even better with RealFuels because of its synergy with Reactions #7 (producing Hydrazine instead of MonoPropellant with RealFuels installed) and #8 (producing hypergolics from Hydrazine) The *only* new resource any of these need is Carbon Monoxide (the rest already exist in KSP-I Extended, or in RealFuels where appropriate)- which could be skipped if we coupled the Fischer-Tropsch Reaction with the Reverse Water Gas Shift Reaction automatically, although I would not recommend that as it would take away a lot of flexibilit from how players implement their ISRU... Carbon Monoxide is also usable in the interesting reaction: 2 CO + O2 --> 2 CO2 Which can be used for a chemical rocket with low ISP directly... (and is particularly useful for suborbital "hopper" designs, and two-stage Duna ascent-vehicles using this for the first stage and HydroLOX propulsion for the second stage, when coupled with the Reverse Water Gas Shift Reaction) Regards, Northstar

The KSP-Interstellar mod already includes the Sabatier Reaction (using realistic chemistry) as well as actually a lot of ISRU reactions (and several more I'm seeking to add, in the latest branch I help develop- KSP Interstellar Extended). We'd love to have your help over there, actually! I've got a long list of ISRU reactions to add to KSP-I, but don't personally have the coding expertise to add them (as it involved modifying the KSP-I .DLL file instead of just configs) and FreeThinker, the other modder/developer who does, seems more interested in crossing other things off his to-do list first... Take a look at THIS list, and maybe it'll whet your interest a little to help out... Items 2-8 on that list still haven't yet been implemented in KSP-Interstellar Extended. Note that some of them are actually multiple reactions (such as the ones to produce hypergolics out of Hydrazine and Methane...) Here's the link again: http://forum.kerbalspaceprogram.com/threads/111159-WIP-0-90-KSP-Interstellar-Extended-0-8-16?p=1790377&viewfull=1#post1790377 Urea Electroylsis (discussed in the update at the bottom of that list) is also a desired reaction, that specifically only activates when both KSP-Interstellar Extended and TAC Life Support are installed- and would allow recycling of WasteWater (from TACLS) into Nitrogen, Hydrogen, and Carbon Dioxide... Regards, Northstar

You're limiting yourself by saying "stock only". The modding community of KSP in an AWESOME asset (call it self-aggrandization, I help develop/maintain two mods myself), and you'd be wise to take advantage of it to spice things up a little... Bored with standard rocket launches? Try a mass driver! Want to fly around on Eve or Duna? KSP-Interstellar Extended Thermal Turbojets work great for that! (as do Firespitter propellers) Until 1.0 comes out (which IMHO is going to happen far to soon unless they release another update first- to allow bugs to be discovered/fixed that QA/Experimentals missed, and really ought not to come until they've at least switched to Unity 5 and made a performance/polish pass in my humble opinion...) you can keep yourself plenty busy with mods. I *strongly* suggest giving it a try... Regards, Northstar

At high concentrations (such as in laboratory or industrial waste), yes, Ammonia is toxic to aquatic life. But at the low airborne concentrations not broken down found in Ammonia Thermal Rocket exhaust, it is completely harmless (the worst it could do is cause irritation to the eyes and other mucous membranes of workers at the KSC not wearing adequate safety gear- whereas the CO from a Kero/LOX rocket could knock them unconscious or kill them if they don't wear proper breathing equipment...) especially considering the dilution-factor when it enters nearby lakes or the sea (agricultural runoff of Ammonia is a much bigger problem- and would contribute a much greater mass of Ammonia to nearby water bodies...) Most aquatic organisms already excrete Ammonia as their normal form of nitrogen-excretion (unlike terrestrial animals, which excrete the less toxic Urea or Uric Acid...) and there are already specialized processes among aquatic plants and bacteria to break it down and utilize the nitrogen... Trust me I'm a biologist in real life- the low levels of Ammonia coming out of a Thermal Rocket aren't going to be a problem compared to even the exhaust of a Kero/LOX rocket, Ammonia-containing industrial waste, or the runoff of much greater quantities of Ammonia from nearby farms. Regards, Northstar

Uhhh, LiquidFuel and Oxidizer should still be valid fuels produced from Water electrolysis when you don't have RealFuels installed... The way we made it to produce LqdHydrogen with RealFuels should have only triggered when a RealFuels installation was detected... If I'm not mistaken, NearFuture Technologies also triggers a MM patch that leads to the production of "Liquid Hydrogen" (the RealFuels version is "LqdHydrogen", only NearFuture Technologies uses "Liquid Hydrogen") instead of LiquidFuel. Are you sure you don't have NFT installed? Regards, Northstar

Awesome! Ammonia isn't really all that toxic, though except in very high concentrations. Unlike with Hydrazine, the *small* amounts that will leak into the environment from a Thermal Rocket aren't going to do any noticeable damage. The Carbon Monoxide from a conventional Kerosene/LOX rocket (not all of the Kerosene gets fully-oxidized, hence the smoke-trail behind a Kero/LOX rocket...) is actually much more damaging to the environment, and we don't (and shouldn't) give Reputation penalties for stock rockets... So I would *STRONGLY* suggest removing the penalty on Ammonia altogether. As for Hydrazine, it's definitely realistic- but it could easily be (and probably currently is based on the description, although I haven't had the chance to play-test it yet) over-done. I would suggest giving it the Reputation penalty Ammonia currently has (Ammonia shouldn't have ANY reputation penalty, its toxicity is so light compared to other fuels like hypergolics and Kero/LOX, it is actually a comparatively *clean* fuel) such as to not be overly-harsh on players. After all, this is a game (and Reputation is much more valuable than you think, as it can be burned for large quantities of Funds or Science...) Further, how do you actually scale the Reputation-penalty? Is it on a per-launch basis (which would unduly penalize very small rockets) or based on the mass/volume of Hydrazine used below a certain altitude on Kerbin? (other planets don't matter) If the former, I would suggest switching it to the latter... Last, but not least, how do you inform players that they've actually been subjected to a Reputation penalty for using Hydrazine/Ammonia in-atmosphere? (although I *strongly* recommend removing the penalty for Ammonia entirely) Do you just subtract the Reputation points without telling them (probably a bad idea), or do you give them some sort of pop-up or message that tells them exactly how much of a penalty they suffered and that it was for using Hydrazine below a certain altitude... I would advise providing players with a pop-up message. And keeping the penalty very small- not more than 5-10 Reputation points (which, with the appropriate strategy, can actually convert to quite a few Science points on a mission- or quite a large discount on a new tech-node at R&D...) for most larger/heavier launches (and less for smaller ones). This is because, after all, Kerbal is a game- and Kerbals are little green men who likely place much less value on their lives and the environment based on all the existing lore (through stock part descriptions and such) and options the game gives you. I would strongly advise keeping the penalty very small to maintain the !FUN! value of KSP... Regards, Northstar

Ummm, sorry for the necro guys, but has there been any news about cycler ships in-game recently? That is, has anybody actually attempted to build one recently? Cycler Ships should be possible in KSP- you basically just need an orbit that leaves Kerbin, passes close to Duna, and comes back to Kerbin a bit further along in its next orbit with a small adjsutment-burn near apoapsis (not exactly the same as a Cyler Orbit in real life due to the restrictions of two-body physics, but close enough...) Is anybody crazy enough to actually give this a try? Regards, Northstar

That would work too. I already play-tested and confirmed that the "is LFO" code is *indeed* active. I don't know why, but it leads to fuels overwriting each other if only some fuel-modes have it. As such, can we just go and get rid of it from the Hydro/LOX fuel-mode? All the other fuel-modes have it removed... Regards, Northstar - - - Updated - - - Ahhh, a Gaussian Function. I thought you were just going linear, which is why I suggested the higher start temps for the curves... What questions do you still want answers to? I don't see any new questions... Regards, Northstar

OK, so with recent code-changes to KSP-Interstellar Extended, the Propulsive Fluid Accumulators now work up until about 250 km above Kerbin in stock (I haven't determined exactly how high they work up to in RSS 6.4x) as the Thermosphere of Earth extends about 500-1000 km high in real life. As such, I moved my Propulsive Fluid Accumulator up to a 240 km orbit. This should allow it to easily transfer to a fuel depot in an even higher orbit, and will make it easier still for spacecraft to phase into position with the fuel depot (or for reusable fuel-tankers to drop down to meet with spacecraft just above Kerbin's atmosphere...) Regards, Northstar

Hi FreeThinker, OK, so the changes to the Thermal Rocket fuels... Can we get a reversal of the ordering of the ISP at least? It took me about 5 seconds of cutting and pasting in my own config file to do this, and I imagine it should be extremely easy to order fuels from lowest to highest ISP in the official config file as well... (which would make it MUCH easier to switch to the propellant with the next-highest ISP during a rocket ascent) In addition to that, could we get a removal of the "is LFO" line from the Hydro/LOX config like I mentioned before? The temperatures that Water and CO2 start decomposing at are currently excessively low for propellants rapidly passing through a heat exchanger. On the other hand, Hydrazine and Ammonia really need much lower decomposition temperatures, or preferably to have this code removed for them entirely. And CO2 should not be depositing soot at the temperatures of a fission reactor- it should be removing it, regardless of whether the rocket is in "CO2 Cleaning" mode or not... Finally, the decomposition-curve for Methane needs to be fixed as well. See my post here again for more details: http://forum.kerbalspaceprogram.com/threads/111159-WIP-0-90-KSP-Interstellar-Extended-0-8-9?p=1824821&viewfull=1#post1824821 Regards, Northstar

Welcome aboard EpicX, although I have no idea what this business about buttons is! Regards, Northstar

Also, some eye-candy to make up for my recent grumpiness a bit: This is the Hydrazine-propelled Nuclear Thermal Spaceplane I designed and flew to orbit in RSS 6.4x that I was talking about needing the Hydrazine fuel-mode for before (well, technically, this is a later redesign of the version that was waiting when I wrote that...) It is shown here de-orbiting after a successful mission to deploy part of the Propulsive Fluid Acccumulator shown earlier... (I launched the probe core, heat radiators, and additional LqdNitrogen tankage in a separate launch) It won't work anymore if Hydrazine is made to (unrealistically) not fully-decay in a 2750 K nuclear reactor though (the temperature of the main reactor after a bit of WasteHeat accumulation). Hydrazine is already routinely used in RCS thrusters that operate at a fraction of that temperature (and basically rely on catalyst beds to reduce the activation energy), and once can rapidly and fully thermally decompose Hydrazine by around 1000 K even without a catalyst (remember, its flash point is a mere 52 C). There's no need to include a Thermal Decomposition curve for either Hydrazine or Ammonia in KSP-I Extended... Especially considering the colder NTR's might well include metal catalyst-surfaces somewhere along the propellant path after the heat-exchanger: Ammonia, Hydrazine, etc. breakdown are easily catalyzed by Iron alloys, for instance... Adding a thin layer of high-temperature steel alloys along the exhaust pathway is not particularly difficult... Regards, Northstar

OOPS! That I did! It appears my previous estimates were quite a bit off, and I refined them after doing some more research... (my more recent estimates are probably more accurate- as they are based on more data) Sorry about that! 50,000 K? Ummm, show me those documents... I really need to see these documents. Is it 5000 K or 50,000 K (50,000 K is halfway to the 100,000 K at which nuclear fusion first starts to occur!) Ammonia isn't an exotic propellant. It's considered one of the most likely propellants for NTR's in real life, and appears in SciFi as far back as the sequel to 2001: A Space Oddessy. It's easily decomposed, and along with Hydrazine, should be fully-decomposed in almost any reactor in KSP-I (except the "experimental" fission reactors that only operate at around 1600K- they might not decompose a very small fraction of the Ammonia or Hydrazine they heat, but will still break down the vast majority...) Glad to know it's fixed, because it turns out the PFA's don't actually work in time-warp at ANY altitude in 0.8.09: Here my PFA was, near the maximum altitude they should work at in stock (250 km) although less than the appropriate cap in RSS 6.4x (around 325 km) and it still wasn't working in time-warp! Actually, the cooling-cost for a tank is completely unrelated to how full it is. It is related to one thing only: the rate at which heat leaks into it (which is entirely determined by the surface area). For that matter the rate at which cryogenics boil off when NOT cooled is also related almost entirely to the surface area (bigger tanks tend to boil off a bit more slowly due to their thinker walls- a tank with 8 times the volume will have 4 times the surface area and walls twice as thick- for exactly the same ratio of tank mass to volume... But thicker walls act as better insulators... All this means that it can sometimes be more effective to split the same amount of fuel into a larger number of smaller tanks, even though each of the smaller tanks requires more electricity relative to its volume (I hope this relationship between tank volume and electrical requirements being non-linear is still represented with the new tank types, as it was with the Nitrogen tanks), if some of the fuel will be used earlier in the mission and some later- so you don't have to cool as much tank volume later in the mission... There is already a way to reserve a certain amount of other uses, and always has- simply forbid certain tanks before performing a burn by right-clicking them and clicking the appropriate arrow next to the fill-gauge for that tank... As for auto-switching, what auto-switching? I've never had my fuels automatically switch during flight- I always have to toggle it manually... AWESOME! Distilling water might increase its cost maybe 10-fold, if that. It isn't exactly an expensive process- I was trusted to operate a small distiller as a TA in my high school chemistry lab back when I was in high school... The equipment to do it isn't hugely expensive- and gets much cheaper for the capacity the more you scale it up... The cost of Water in TACLS ($5.76/liter) is already more than 100x what it should be based on real life costs. The value KSP-I uses is fine if we assume highly-expensive filtering processes were used. Hmmm, indeed there does seem to be a mis-match between the radiator "surface area" value in the config and the actual size of the physical model. It's not that they radiate too much heat for their surface area (according to the part config), those values are realistic for all radiators as I explained before- it's that the model is too small for the surface area we assign it... But yeah, a decrease in the assigned surface area to match the model, or an upscaling of the model to match the surface area might be in order... Interesting. Cool. Regards, Northstar

Current thermal radiation is based on real-world performance: we even reflect the approximately 70% higher thermal emissivity (compared to any normal material) that is possible with graphene through meta-material properties... Regards, Northstar - - - Updated - - - I missed this before, and only came across it now by a search... Yes, it does appear my information was outdated- I know that TACLS did at one time use a different density (most likely by not assuming 1 units = 1 liter). It appears it has been using the correct density for some time now, however, and the only real issue with it is the absolutely insane cost it has of $0.80/liter in 1965 dollars (using the 1 Fund = $1000 1965 USD convention...) making it come out to $5.96/liter in 2015 dollars- which is more expensive than bottled water! (which is sold at ENORMOUS profit ) Regards, Northstar - - - Updated - - - @FreeThinker, It appears there is currently an issue with the way Propulsive Fluid Accumulators work, introduced by your recent increase to the max altitude they work at: Propulsive Fluid Accumulators no longer work below 100 km! (testing by raising this satellite's altitude revealed that to be the cut-off point...) It appears you also introduced a minimum collection-altitude, possibly intentionally? This is not actually realistic- while in real life, PFA's operate at a minimum altitude of 100 km, Earth's atmosphere is much taller than Kerbin's! (and indeed the proper "atmosphere" extends slightly ABOVE 100 km in full-scale RSS!) They only operate this high up because drag rapidly increases below the Thermosphere, making it difficult to combat it effectively in the thrust-range of an electric thruster... (with a powerful enough electric thruster, you *can* collect below the Thermosphere, just as you can do in KSP-Interstellar within the proper atmosphere given enough electric power available to a plasma thruster...) The "edge" of an atmosphere in KSP is the best analog to the edge of the Thermosphere, being at approximately the correct pressure for the point at which drag rapidly increases and the Thermospehre ends (when descending)... Thus, there is NO NEED for a "minimum" altitude for Propulsive Fluid Accumulators in KSP- and it also creates potential problems with trying to collect around planets other than Kerbin (such as Duna, for instance) where the atmosphere begins at a different height (Propulsive Fluid Accumulators could operate much lower around Mars, for instance, due to the thinner atmosphere and lower orbital velocity...) At least PFA's still currently work quite well within the actual atmosphere (in RSS 6.4x it starts at 91 km), if you can find enough power to combat the drag, which is realistic... The problem with this being, of course, you cannot use time-warp within the proper atmosphere. Summary: - Please remove the minimum collection-height (as long as a PFA is above the "atmosphere" in KSP it should be able to collect in extra-atmospheric mode corresponding to scooping inside the Thermosphere...) It is both annoying for players and unrealistic. Regards, Northstar

OK, FreeThinker, having just taken a look at the new EnginePropellants file for the first time, some IMPORTANT thoughts/comments on the REAL fuels (ones with real-life counterparts, i.e. I completely ignore LiquidFuel, LFO, Kethane, and the older NearFuture version of Hydrogen with an arbitrary density- as these can all have basically any stats you want to give them without corresponding to reality...) (1) The fuel-modes seem to be somewhat ordered in terms of DESCENDING Specific Impulse (starting with LqdHydrogen, which has the highest, and working down to LqdCO2 Cleaning, which has the lowest), but you want them to be ordered in terms of ASCENDING Specific Impulse (that is starting with Lqd CO2 Cleaning and working up to LqdHydrogen). This is because the normal, fuel-efficient way to use a thermal rocket is always to start with the lowest-ISP propellants first, and work through that list to get to the higher-ISP propellants, as you get MUCH better Delta-V for the same spacecraft when you consume your less efficient fuels first... With Thermal Rockets you add in the factor that the lower-ISP fuels generally have better Thrust (and the spacecraft will be heavier at the beginning of a mission) and you have even more incentive to move from lowest to highest ISP... (2) The "Hydrolox" fuel-mod still contained the "is LFO" code even though ALL the other fuel-modes had it removed. This needs to be removed for the next update of KSP-Interstellar Extended as it messes up the intended ISP and TWR, and causes issues when some fuels have "is LFO" defined and others do not (causing one fuel-mode to overwrite another's intended Thrustmultiplier and ISP...) (3) The new thermal-decomposition code assumes that Ammonia must be heated to an excessively-high temperature to fully-decompose. The code assumes a 7000 degrees Kelvin heat exchanger is necessary to fully-decompose Ammonia, whereas in reality Ammonia is easily fully-decomposed by a mere 1100 degrees Celsius (1373.15 Kelvin). You need to fix this, and, I suggest, remove the decomposition-curve entirely as it will fully-decompose with *ANY* heat exchanger in KSP-Interstellar Extended (the coldest ones it KSP-I Extended being the experimental fission reactors for CTT which operate at around 1600 K...) (4) Similarly, Hydrazine fully-decomposes between about 800 and 1000 Kelvin in real life, meaning it will fully-decompose with effectively any nuclear reactor of Microwave Thermal Receiver in the game. But you have it not fully-decomposing until about 6000 Kelvin, which is COMPLETELY unrealistic... I don't think a decomposition-curve is necessary for either Hydrazine or Ammonia (as both fully-decompose at temperatures below the coldest heat exchangers in KSP-Interstellar), it only needlessly complicates the config file... (5) The temperatures you assume that Water (2000 K) and CO2 (1000 K) start decomposing at are excessively low. In practice, no observable decomposition of either will occur in the very brief time the propellants spend at this temperature before exiting the rocket below at least 3000 Kelvin or hotter... In short, you got nerf-happy with using the Thermal Decomposition curves to in effect, reduce the Thrust and ISP multipliers for a number of fuels. You need to remove these curves entirely for Ammonia and Hydrazine (as full-decomposition occurs by the temperature of ANY heat exchanger in KSP-Interstellar) and increase the decomposition temperatures for Water and CO2- the latter of which would be used to CLEAN soot off nuclear reactors, not be something that *deposits* it (which is the effect you produce by giving LiquidCO2 a positive SootFactor and a minimum decomposition-temperature of 1000 Kelvin...) When chemicals start having the OPPOSITE effect of what is expected based on reality (depositing soot rather than removing it, for instance) you know there's something wrong with the balance... You're only going to upset both realists (such as myself- also one of your co-developers...) and veterans used to better fuel-mode performances with these unnecessary and unrealistic nerfs to the fuel-modes through the new Thermal Decomposition curves... Please correct the values as I noted in the 5 comments above... Regards, Northstar P.S. I suggest you actually go and carry out some interplanetary missions in Real Solar System 6.4x or larger before you start assuming things are too powerful. *IF* they are in Stock, it's SUPPOSED to be that way- as KSP Interstellar always is and has been a mod based on introducing essentially realistic technologies and performance into KSP, even if some of them (such as the Warp Drive with which it started) seem over-powered. I've noticed this again and again with any developer who gets their hands on KSP-Interstellar, they keep trying to fall into the trap of nerfing the performance to seem "balanced" compared to the arbitrary standards of stock and NearFuture performance, the former of which is entirely fictitious and the latter of which is excessively-weak compared to reality when you look at anything they do with nuclear reactors, and considered "useless" even by a great many stock-veterans who have spent much time using that mod's nuclear reactors, including myself... (I can also point you towards some rather derogatory comments about the utility of the excessively-nerfed NearFuture mod by players like Geschosskopf, after his experiences with the "Argonian"...) Trust me, the nerfing-trap is NOT one you want to fall into. Stick with the realistic performance, and let REALITY dictate your balance- you'll end up getting something that is both fun and believable in the end, regardless of how "balanced" it seems compared to stock performance... (if players want to fly around a miniature solar system with little green aliens, then who are we to tell them they can't have realistic rocket performance? Players can already impose their own arbitrary restrictions or nerfs with the tweakable parts of the KSP-I Extended config if they want, but imposing realistic performance is MUCH harder to do after-the-fact without extensive research by players if the mod wasn't already designed that way to begin with...) - - - Updated - - - Ergh, correction, CO2 doesn't thermally decompose until temperatures of at least 3200 K, and only then at pressures approaching 100 atm (such as on the leading-edge of a capsule during re-entry...) In practice not until at least 5000 K at the pressures of a Nuclear Thermal Rocket, with an upper temperature of 7000 K seeming appropriate: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCQQFjAA&url=http%3A%2F%2Fwww.researchgate.net%2Fprofile%2FMatthew_Oehlschlaeger%2Fpublication%2F241688099_Carbon_Dioxide_Thermal_Decomposition_Observation_of_Incubation%2Flinks%2F00b4951ca0124e1e66000000.pdf&ei=gScjVceJH8SHsAWZrIDoBQ&usg=AFQjCNEXucnCWbdaWOAWt4_UGXWhCmXaPg&bvm=bv.89947451,d.b2w&cad=rja Water, on the other hand, thermally decomposes a bit colder- starting to rapidly decompose at about 2200 K (it slowly decomposes much colder), with more than half of the molecules decomposing at 3000 K... However this is after PROLONGED incubation at these temperatures. When rapidly moving through a nuclear thermal rocket, you're probably not going to see appreciable decomposition in that brief time-frame below about 3000 K, and not full-decomposition until at least 4200 K or so... http://en.wikipedia.org/wiki/Water_splitting#Thermal_decomposition_of_water Finally, Methane isn't going to require temperatures of 15,000 K to fully-decompose. It should be fully-decomposed by around 3000 K, considering you can quite rapidly decompose it after about 1000 K... So, it's only not going to fully-decompose in some of the coldest heat exchangers in KSP-Interstellar... It's frankly kind of silly that it currently doesn't start decomposing until a higher temperature than CO2 in the mod... (1500 vs 1000 K) Summary of appropriate decomposition temperature-ranges for Thermal Rockets: CO2: 5000-7000 K (NO soot deposition below 5000 K! CLEANS soot below 3000 K...) Water: 2200-4200 K Methane: 1000-3000 K Regards, Northstar