Northstar1989

Sorry for the delay since the last update. I was working on trying to fix an issue related to accidentally pre-deploying a parachute (for some reason, KSP doesn't give you a way to cancel pre-deployment) and losing a vessel as a result by editing the save file to set the parachute back to "Stowed". Eventually I figured it out... Anyways, the news is, Jebediah Kerman is now dead! Although my rocket was able to withstand the high G's of this re-entry and landing (except the Science Jr., which crumpled on splashdown as the landing legs were unable to protect it during the 8.4 m/s ocean landing...), Jebediah's fleshy body was not. The G-forces just barely exceeded maximum crew tolerances. Too bad there's no way to give Kerbals with a "badass" tag like Jebediah 1 or 2 extra G's worth of tolerance (or a few more seconds beyond the limit- which is all it would have taken for his survival...) Even with my best efforts to bleed off speed high in the atmosphere (by deploying the landing legs and turning the craft sideways), nothing was effective- and Jebediah now rests in an honorable grave (the capsule was safely recovered, even though the pilot was dead), a martyr to the cause of Kerbal science... He will be remembered. Future generations of Kerbals will sing praises in his honor. Regards, Northstar

This. Awesomeness. I figured out on paper that this was possible AGES ago, but never had the time to actually attempt it. It's nice to know that it actually works... Regards, Northstar

Yes, my mistake, I was thinking at least partially of the N-1 (or Energyia, perhaps). But my main point was that LH2/LOX were NOT used on the LEM/CEM- so you guys have missed the main point of my post- the gold foil tanks on the LEM were used solely to hold hypergolics, *NEVER* LH2. Regards, Northstar

That's what's meant by the term "boil-off"- the leakage of molecules through the tank walls into space. The Hydrogen doesn't actually have to be in GAS form to boil-off, it just does it much quicker in this state than when it's a liquid. Also, the cooler it's kept, the more slowly this occurs, even when in liquid form. Methane, as you mentioned next, is composed of larger, slower-moving molecules- so it experiences much LESS boil-off at the same temperatures and pressures (virtually ALL fuels experience boil-off, even Hypergolics- it's just a matter of orders of magnitude as to how fast it occurs...) This is why the Boeing/ULA proposals to build fuel depots at the La Grange points relied on Meth/LOX as the stored fuels instead of LH2/LOX. That being said, it still would have required an active cooling system... That's a known problem for Nitric Acid, but not really a significant problem for LOX or N2O4 (though I think very small amounts of N2O4 actually do break down into Nitric Acid over a period of YEARS). LOX, in particular, isn't going to react particularly corrosively with an aluminum tank- aluminum actually becomes MORE stable when it's covered by a thin layer of (non-reactive) Aluminum Oxide at the molecular surface... No, fuel aren't necessarily going to do *either* of those things. That was the whole point of Hypergolics (aside from those systems using Nitric Acid)- they can be (and have been, in the case of nuclear missile silos) stored in sealed tanks for YEARS at a time without consequence... And if you add an active cooling system, you could actually easily freeze many Hypergolics into their solid states- which would be *incredibly* stable over long periods of storage in a cool, dark, isolated fuel tank in space... The main issue with Hypergolics is their toxicity- which only becomes an actual problem is something goes terribly wrong- like when the Apollo-Soyuz astronauts accidentally left a certain air vent open during re-entry that allowed N2O4 fumes to seep into the capsule... http://en.wikipedia.org/wiki/Dinitrogen_tetroxide#The_Apollo-Soyuz_mishap O.o I may have mixed that up. I'll have to double-check my facts on that one. I know there HAVE been numerous fuel transfers in space, however- as was already pointed out with Soyuz and the Russians... Regards, Northstar

Whooo, whoooo, here does the tangent train through yet another station! Seriously, though, if you're going to discuss LEO Propellent Depots (the whole reason I even brought the subject up was to point out it could have been a major secondary use of the Energyia rocket besides Buran- one that was never available to STS due to is passive external fuel tank...) then at least bother to read the articles you're posting. The Wikipedia article, for instance: https://en.wikipedia.org/wiki/Propellant_depot IF any of you had actually read through the entire article you were posting, you would have noticed two overwhelming trends: (1) Almost all of the engineering challenges presented were also matched with solutions- many of which had already been developed and proven. (2) Almost all of the discussion on Wikipedia focused on use of Liquid Hydrogen and Oxygen (cryogenic propellants), rather than storage of Hypergolics. If you consider the article as a whole, it quickly becomes apparent that the main issue with LH2/LOX is boil-off (these fuels DON'T degrade), and that it can be easily be overcome by simply actively cooling the propellant- that is by running a heat exchanger to keep the fuel cold, instead of simply relying on passive insulation to do the entire job (which would require ignoring all the laws of Thermodynamics- any temperature difference between the fuel and the environment is bound to eventually even out without some sort of energy input to maintain that difference). If you don't want to bother with this, the solution is even simpler, USE HYPERGOLICS. Aerozine 50 (a 50/50 mixture of Hydrazine and UDMH), one of the simplest and most common hypergolic fuel-mixtures ever developed, solves the whole problem of boil-off quite elegantly: its boiling point is higher than room temperature (gasp!) so that boil-off isn't such an enormous issue. It also is storable for YEARS at a time without significant degradation or boil-off, due to the particular stability of UDMH (a hypergolic fuel which is more stable than Hydrazine- but also less dense and more prone to boil-off) and the boiling-point elevation by including Hydrazine in the mixture... Aerozine 50 was what they once used for nuclear ICBM's, because it is easily stored for long periods of time without degradation/boil-off or the requirement for maintenance of cooling systems. And, like most Hypergolic fuels, it is MUCH denser that LH2/LOX, which means you can pack a LOT more Delta-V into the same fuel tank mass *despite* its lower ISP... Hypergolics were what they used for Apollo's LEM/Service Module, back when they actually wanted to GET somewhere- instead of just fooling around in Low Earth Orbit with LH2/LOX to make the United Launch Alliance piles of money... (from a cost AND performance standpoint, KeroLox and/or Hypergolics as vastly superior for most other purposes, due to their lower boil-off and higher fuel-density...) The toxicity isn't really all that big of an issue, when you consider the astronauts are already sitting on top of a giant carefully-controlled bomb. And it's REALLY NOT an issue AT ALL when the hypergolics would be stored in an unmanned fuel depot (the only astronauts going anywhere near it would be in sealed EVA suits, for maintenance duties if ever needed), and that fuel depot would mainly only be docked with by GEO unmanned satellite transfer-stages. Oh, and Sky_walker, you think fuel-transfer has never been performed through docking ports before? With all due respect, you couldn't be more wrong. Not only did they make *extensive* use of it on the Apollo missions (in fact, the explosion on Apollo 13 was initially attributed to an issue with stirring the fuel tanks before transfer between the LEM and Service Module), it was also performed between two UNMANNED craft for the first time in 2007, according to the link which was already cited before on propellant depots, and which I linked to again earlier in this post just for your convenience... Regards, Northstar

So, any news on if this works in 0.25? Also, I have a problem with a craft that has its parachute pre-deployed outside the atmosphere, that I need *not* to be pre-deployed (it keeps opening too high in re-entry and killing Jebediah from the G-force shock- and then quickly burning up from re-entry heat, causing the capsule to strike the ground at terminal velocity later on). How would I go about editing the parachute back to the "undeployed" state? Regards, Northstar

And here is my second mission- a suborbital manned mission for !SCIENCE! Regards, Northstar

EDIT: Sorry guys. I accidentally corrupted the save for this game while making changes to my installed mods. As such I am going to have to close the thread down and start afresh (next time with more starting Funds/Science so I don't have to repeat so much of the initial effort). I'm at it again! I'm making a Career Mode thread documenting my progress, and adding in a healthy dose of writing/explanation/narrative... This time, though, I'm going to try and keep it much shorter and more to-the-point. Expect only screenshots/videos/live broadcasts of the more interesting missions- no more frivolous contracts! (unless something particularly hilarious happens) And, keeping that tendency in mind, here are the screenshots for my first flight (yes, a *FLIGHT*- I started with enough Science to purchase the Aerodynamics tech node, and am running Firespitter) The plane was called the "Griffon" because I had thoughts about re-using it. However FAR is acting *extremely* weird (with all sorts of phantom forces and instabilities on many perfectly good designs- rockets and planes are a LOT less stable they should be, or were in 0.24.2, with the first 0.25 release), and refusing to allow itself to be controlled either with MechJeb2 or its own Flight Assistance system- so I decided to shelf the idea of performing lots of plane flights after the tedium/annoyance of having to constantly manually correct this plane's Angle of Attack... My mods (subject to change/addition) Active Texture Management Ferram Aerospace Research Deadly Re-Entry: Continued Kerbal Joint Reinforcement Atmospheric Trajectories Flight Manager for Reusable Stages NovaPunch2 (fairings deleted) RealFuels + "Stockalike" config (engines ONLY- using stock RCS for KSP-Interstellar ISRU ability to manufacture Monopropellent) Procedural Parts Procedural Fairings Procedural Dynamics (aka. "Procedural Wings") KSP Interstellar Near Future Solar Precise Node Firespitter MechJeb2 Regards, Northstar

They're definitely accurate. MechJeb clearly indicates the maximum TWR the lower stage is even capable of with the set thrust limits is 2.04 when I select "All Stats" (talk about taking it slow and careful- this was the LAST spacecraft I would ever expect G-force deaths on...) and the rate of velocity gain on the navball was in line with the TWR only being 1.7 by the time Jeb died... Here are screenshots of the launch vehicle, if it helps you try and reproduce the problem any: I'll be attempting to reproduce the bug on my own install in just a second... Regards, Northstar EDIT: Just added an image showing the MechJeb2 "All Stats" screen so you can see the TWR isn't capable of exceeding 2.04 based on the rocket thrust (and when the G-force death occurred, the rocket was flying straight up at moderate speed- so it shouldn't have experienced excessive aerodynamic forces either) EDIT #2: Strange, doesn't seem I can reproduce the bug either. I had my rocket fly through its entire first stage without issue this time around... I guess keep an eye out in case this kind of thing pops up again though.

Or, you could use an Energyia rocket to launch the fuel. Without the docking hazard of sending a million small rockets to the orbital fuel depot, and for less Delta-V than the small rockets would have consumed. Giving Energyia an actual, real use besides just launching the Buran shuttle or Mars/Moon-base missions... Which was kind of my point here... We've probably gotten too far off topic if we're talking about nuclear politics on a Buran/STS thread. My point was just mainly that Energyia could be used for efficiently launching large quantities of fuel to orbital fuel depots, and fuel depots add value to reusable nuclear tugs (which otherwise have to dock directly with a fuel tanker every time they need refueling- which is inefficient if the tug doesn't need a full fuel load for a given mission, but the tanker is designed to carry a full fuel-load for the tug...) Microwave Thermal is better than nuclear. Better because you can actually achieve the same specific impulse (700-1000s with Liquid Hydrogen) for a lot *less* engine-mass (you don't have to push around a heavy nuclear reactor), without any of the political hazards of launching something nuclear to orbit... And since the tangent-train has clearly already run the station... Microwave Thermal may not have any working flight-prototypes (although the related craft of a Lightcraft *has*), but it's been the subject of countless feasibility and engineering studies proving it is a realistic option, as well as a LOT of media attention: http://core.kmi.open.ac.uk/download/pdf/4871859.pdf http://www.cnet.com/news/rocket-scientist-aims-to-relaunch-propulsion-technology/ http://physics.le.ac.uk/journals/index.php/pst/article/view/190/106 http://www.astrobio.net/news-exclusive/beaming-rockets-into-space/ http://callcenterinfo.tmcnet.com/news/2011/04/30/5477779.htm http://nextbigfuture.com/2011/05/beam-powered-space-propulsion-work-from.html Note the first link in particular, which calculates an actual ascent trajectory for a Microwave Thermal Rocket easily within the reach of current technology... Regards, Northstar

It depends a LOT on the specifics. Theoretically, a slingshot can be a lot more effective- it can add up to twice the orbital velocity of a planet around the Sun or a moon around a planet to your spacecraft, *if approached from the correct trajectory and angle*. However, achieving the angles and velocities necessary relative to the Sun for that kind of an assist are so difficult and/or expensive in terms of Delta-V that you're MUCH better off with an aerocapture. In practical terms, an aerocapture is much easier and should be more than enough. For instance, if you aerocapture into an elliptical orbit around Duna with a periapsis *just above* the edge of Duna's atmosphere (you'll need to perform a *slight* prograde burn at apoapsis to achieve this periapsis), and an apoapsis at the very edge of the SOI; then you could theoretically gain up to the escape velocity of the planet (which for Duna is 1372 m/s) towards your next leg of the journey further out, if your target was far enough out that your escape burn ensured you lost almost no velocity on the way out from Duna... (this would mean a burn for a transfer to a different *star system* however- in practical terms, your gains are more likely going to be limited to around maybe 700 or 800 m/s) However, as I stated before, aerobraking at Duna to get to Jool would actually cost *more fuel* if you looked strictly at Delta-V costs (you would have to travel to a destination significantly further out than Jool for a Duna aerobrake to save Delta-V directly: think a trip to the Sentar system in Krag's Planet Factor...) The main benefit is that you can perform a much more ACCURATE pair of transfers this way than if you just went directly to Jool- which means you can use lighter engines (which increases your total Delta-V budget) and subject your rocket to fewer G's of acceleration. And the equation changes ENTIRELY if you're using ISRU- in which case the total rocket mass you need to launch from Kerbin orbit becomes MUCH smaller (than a direct transfer, or refueling around Duna using tankers) if you can build a reusable fuel infrastructure around Duna... Oberth efficiency is related to gravity gradient in not one but two ways: The first is, of course, the potential amount of fuel you can save using the Oberth Effect. That is positively related to the strength of the gravity field, and thus the velocity of your starting orbit. The faster your orbital velocity, the more energy you gain for each each second your engines are firing... The second is how much of that potential you can actually reasonably harness with a given rocket design. This in negatively related to the strength of the gravity gradient. The stronger gravity is, and the less sharply it falls off as you leave the planet (a larger planet with a lower density and the same surface gravity is more challenging in this regard- hence one of the many reasons Real Solar System is so much harder than stock despite Earth/bigger Kerbin having EXACTLY the same surface gravity as stock Kerbin...), the more kinetic energy you'll lose from the start to the finish of the burn. This is due to two factors: stronger gravity fields are less forgiving of long burn times, and your burn time will need to be longer in order to escape the gravity field in the first place. The first of these there is nothing you can do to change, other than launching from a lower orbit around a more massive body. The second, however, you can somewhat counteract by giving your rocket more powerful (and thus heavier) engines, and performing one or more "periapsis kicks" so more of your burn is performed at greater orbital velocities... Burn time basically is negatively related to your TWR around the body you are orbiting, and the stronger the gravity, the lower your TWR with that planet, and the longer your burn time for the same rocket design. So a two-part journey that makes a pit-stop around Duna has the advantage of shorter ejection burn times BOTH due to the lower Delta-V requirements for each burn, AND the higher TWR your rocket will have with the same engines when orbiting Duna due to the weaker gravity... Regards, Northstar

Read the explanation carefully. Aerocapture increases your velocity relative to the *SUN* in the situations described (at the terminal end of a transfer orbit), NOT relative to the planet. The planet is moving faster than you relative to the Sun when you are in its SOI- and your velocity relative to the planet is actually its velocity relative to you (from the frame of reference of the Sun, you're moving slow and the planet is moving fast). So anything that decreases your velocity *relative to the planet* in that situation increases your velocity relative to the Sun. I'm not sure what you're trying to say here. You can make a slingshot relative to the Sun around any planet orbiting it, given the right velocity and angle of approach (conversely, you can also perform a gravity *brake* instead of an assist, if you pass the planet on the opposite side from an assist...) Gravity slingshots are NOT an artifact of the Patched Conics method of predicting trajectories used by KSP- they're a thing in real life. In fact, NASA used a whole bunch of them for the Voyager and Galileo missions: http://www2.jpl.nasa.gov/basics/grav/primer.php Regards, Northstar

Jebediah definitely died. His portrait in the corner disappeared and everything. Fresh install of KSP with 0.25, hadn't even heard of that screen before now. So *I* definitely didn't change any of the settings... Yes, Jebediah *IS* on top of an SRB. In a 1.25 meter crew capsule on top of the "MassiveSRB" from Stock. Separated by a (not yet staged) DRE decoupler. But it doesn't matter what the potential thrust of an SRB is, only the ACTUAL thrust. And the MassiveSRB was not yet activated at that point- only 3 (thrust-limited) BACC SRB's in the stage below it. The TWR was only 1.7 at that point in the flight, as the flight log correctly indicated. The craft was EXTREMELY simple. Basically a 1.25 meter Command Pod (with a reduced amount of AblativeShielding and no Hydrazine) on top of a MassiveSRB (seperated by a DRE decoupler) which was not yet activated and sitting on top of 3 thrust-limited BACC SRB's under a tricoupler, with another decoupler between the bottom of the MassiveSRB and the tricoupler. A basic understanding of physics would dictate VERY LOW forces on the Command Pod. Since all the heavy parts were below it, basically there should only be enough upward force left after gravity on the parts lower down to lift the Command Pod at less than 2 G's- with a little drag on it from above (FAR was installed, and the speed wasn't that high: so not a lot of drag) which shouldn't have been a very big deal... OK, maybe that's NOT as simple as it sounds. I'll try and get a screenshot up of the rocket in a second. Regards, Northstar

Yeah- that one's a load of !FUN! Is it currently filed with the Squad bug tracker? It REALLY needs to be fixed in a future update. Regards, Northstar

I have a major bug to report: Crew members are dying at unreasonable G-loads. As in Jebediah dying from less than 2 G's, DURING LAUNCH... I've no idea what might be causing this, but I can look for any hints in the game log next time I find it... Regards, Northstar

LH2/LOX wasn't *used* in the Apollo landings. It was Kero/LOX (Saturn V lower/upper stages) and Hypergolics (LEM, CEM, etc.) all the way. The only place LH2/LOX has actually seen significant use is for launch vehicles to LEO- which is where it makes absolutely the LEAST sense... (you *lose* Delta-V for the same tank volume compared to Kero/LOX or Metha/LOX due to the lower fuel density in that Delta-V range...) I think some people get the wrong idea because they see the gold foil used on the Apollo landers, and automatically assume that was used to hold Hydrogen. Actually, that was used to hold Aerozine/N2O4: http://en.wikipedia.org/wiki/Apollo_Lunar_Module Regards, Northstar

How come it works for you??? I just installed RSS 6.4x, and the KSC appeared hovering over the water near the coast instead of at the proper altitude. What ModuleManager version were you running? Were you running a dev version of the 6.4x config files? (I was running the latest dev build, which might have been part of the problem- but it wasn't working *at all* with the latest release last time I tried...) Regards, Northstar

Surprisingly, you're right. It took some research of my own to confirm what you were saying, but apparently because the structural stresses on a fuel tank wall increase in proportion to not only the pressure, but also the volume of the tank, the tank mass does indeed scale linearly with fuel volume. Notice that there is no place in the equation for the weight of the propellant- a fuel tank at STP will weigh the same regardless of whether it's holding 2 tons of LH2 or 16 tons of CH4, for instance... (which would have exactly the same volume and pressure) Of course, the 16 tons of CH4 will be worth a lot more Delta-V, even with the lower ISP from burning it or using it directly in thermal rocketry... (and the operating pressures using methane will be lower for the same thrust due to the higher molecular mass- meaning you can save weight on the engine or achieve much higher thrust for the same chamber pressures...) Makes me wonder why ANYBODY in their right mind would ever use LH2/LOX instead of hydrocarbons (CH4/LOX or Kerosene/LOX) for propulsion in the Earth-Moon system... The higher ISP of LH2/LOX doesn't become worth the lower fuel density and/or higher tank mass unless you are transporting them a TRULY large Delta-V gap- like to Mars or Jupiter- in which case boil-off is a serious issue... And Kero/LOX or Metha/LOX rockets will be SMALLER than LH2/LOX rockets, thanks to their higher fuel density- which means they will experience less atmospheric drag losses during ascent thanks to their better Ballistic Coefficients... Regards, Northstar

Awesome- but the mod isn't released yet... Any ETA on the first release? Regards, Northstar

You're not listening to the arguments I made again. The whole problem with larger launches in launching satellites is that you have trouble matching multiple satellites into a single launch. However when using a large launcher to lift a single monolithic payload (like 100 tons of hypergolic fuel to LEO), you don't have that problem at all... What you DO have is the Delta-V advantages of larger rockets (larger rockets require less Delta-V to make orbit because they lose less Delta-V to atmospheric drag, due to their better ballistic coefficients...) as well as the cost and mass-savings of needing fewer total control/guidance systems (the recurring cost of building a control/guidance system for a single 100 metric ton lifter will be a lot cheaper than four separate control/guidance systems each rated for a 25 metric ton payload-capacity rocket, and four guidance systems are heavier than one...) The points of Aquarius were two-fold: one was to take advantage of mass-production of rocket parts and simply build lots of small lifters (like I said before, you will NOT benefit from mass-production when you are talking 25 vs. 100-ton lifters), the other was to build rockets to much looser engineering and reliability standards (which would hurt rocket reliability, but save a lot more on the costs of actually building the rocket- which would allow you to more than afford to compensate for the failures by launching !MOAR! cheap/unreliable rockets for cheap/easily-replaced payloads, such as fuel...) Aquarius also would have benefited from making aquatic launches (hence the name) rather than land-based launches, but that's another story... As for the nuclear tug, it would have greatly reduced the mass you need to launch to orbit in the first place- and is entirely separate from using large, Big Dumb Boosters to launch huge payloads of fuel into orbit in monolithic Sea Dragon style aquatic launches (THIS style of Big Dumb Booster is still highly reliable- just built with looser engineering standards AND much greater safety margins...) or using something like the Energyia rocket instead. Speaking of which, back to the topic at hand- the whole point I was making is that Energyia is superior because for a fraction of the development cost of the Space Shuttle, they also got a Heavy Launch Vehicle with a greater payload capacity than the up-and-coming SLS out of the deal... All you had to do was rip off Buran, add an upper stage, double the number of liquid-fueled radial boosters (Energyia was specifically built to allow for all these modifications) and you could easily lift 175 tons into Low Earth Orbit. And, it was a highly-reliable rocket, nothing like Aquarius- which meant you could also use it for manned missions to Mars, or even to construct a long-term Moon base... Regards, Northstar

Actually, the KSP-Interstellar .CFG was called "MFS KSPI", so it doesn't start with "KSPI"... Anyways, I came up with some ModuleManager scripts by basically copying-and-pasting the scripts already used in that file and changing the resource names and relevant numbers to do some of the same things for MethaLox NTR fuel and Ammonia NTR fuel, as well as making the Ammonia tank modular. Some work could still be done in limiting the Ammonia tank to just holding LqdAmmonia (note it needs to hold the RealFuels "LqdAmmonia" rather than the old KSP-Interstellar "Ammonia", which is why I just went and made the tank modular as a temporary fix), and in making LiquidWater the right density and one of the modular fuels with KSP-Interstellar installed. Still, it's progress... Here's the link to the RealFuels/KSP-Interstelalr Integration Config thread (specifically, to the post with the new scripts) where my progress so far can be found: http://forum.kerbalspaceprogram.com/threads/95671-RealFuels-KSP-Interstellar-Integration-Config?p=1459379&viewfull=1#post1459379 Regards, Northstar

You're not listening to what I'm writing, at all. What I SAID was that you could launch the satellites, and their transfer stages to GTO, empty. You would then fill them up with their transfer-stage and station-keeping fuel BEFORE sending them to GSO for the first time. Obviously, this would require a slight re-design of satellites to allow them to be fueled up in-orbit... There was no discussion of refueling satellites AFTER they had already reached GSO with additional station-keeping fuel, and unless we could find a way of getting fuel to LEO or GSO cheaper (such as LEO atmospheric-accumulators, Lunar IRSU fuel production with a reusable transfer infrastructure to LEO/GEO, or higher-ISP propulsion systems reducing the overall needed fuel mass), it probably wouldn't make economic sense... Nuclear Thermal Rocket tugs have been technologically viable since the 1970's. Although an entirely DIFFERENT issue than setting up LEO/GSO fuel depots (which work just fine with specialized high-efficiency, low-cost tankers: which could also be much less reliable than those lifting expensive payloads, for big cost-savings, via the Big Dumb Booster and Aquarius concepts of the exponential relation between engineering margins and reliability in rocketry and cost...), they do benefit strongly from having them already in operation. They can use some of the same propellants as chemical rockets (H2 or Methane), and simply get better Specific Impulse from them. Also, a single reusable Nuclear (or with modern technology, Microwave-powered) Tug could replace the cost of launching potentially DOZENS of single-use GSO transfer stages, leading to large cost savings- especially if those transfer stages were refuelable upon first reaching LEO, which would add significantly to their cost (even while greatly bringing down overall mission cost, as the fuel could then be launched on much cheaper launch vehicles... Aquarius rockets could achieve launch costs less than 1/20th current costs-per-kg, for instance: though at the cost of a 33% launch failure rate...) Regards, Northstar

DISCLAIMER: Here follows a LONG tangent on the expansion of ISRU, specifically to allow production of the more advanced RealFuels propellents: If you're interested, I'm looking to see if I can't round some people up to attempt something TRULY ambitious- the addition of a realistic set of new ISRU reactions to KSP-Interstellar that are only activated when RealFuels mod is present... These would allow players to actually make some of the more useful fuels in RealFuels mod- Kerosene for Kero/LOX engines and Hypergolics for UDMH/MMH/Aerozine engines (which all burn in combination with N2O4) via In Situ Resource Utilization... This is a (somewhat edited) re-paste of a message I wrote to a guy PM'ing me about a KSP-Interstellar/RealFuels integration config (and specifically, about expanding the ISRU system). So bear with me if it seems like I'm going a little off-topic or addressing questions that were never asked: If you want to ADD more ISRU reactions to a KSP-Interstellar/RealFuels config, now might be a good time to approach FractalUK about adding them to KSP-Interstellar's existing (but IMHO still rather skeletal) In Situ Resource Utilization system. He's currently in the process of re-writing (the new GUI, for instance) and possibly expanding the ISRU system in a coming update (probably one of the first 0.25 ones, since 0.25 will require a major re-write anyways) so now is the PERFECT time to start preparing the way to work with him to add more reactions to ISRU when the time comes... I started a thread explicitly on ISRU quite a while ago- feel free to use it as a public focus for more discussion on the topic... (that way, we might draw more people/information into the discussion) http://forum.kerbalspaceprogram.com/threads/68797-In-Situ-Resource-Utilization-Useful-Reactions Regarding the Fischer-Tropsch Reaction, AFAIK it's really only *marginally* heavier than a Sabatier Reacton, and should be perfectly viable in space. They used to use Sabatier Reaction and Fischer-Tropsch all the time back in the 1800's in relatively small/simple and lightweight chemical refineries in order to produce Kerosene/Methane for street lamps and early cars and such back before the Oil Industry really began to hit it big... The Germans also relied on Fischer-Tropsch (as well as Coal-Liquification) back in World War II in order to produce fuel for their tanks/airplanes when the Allies cut off their access to oil from the Middle East/ Baltics, if my memory of history serves me correctly... Anyways, both Fischer-Tropsch and the Anthraquinone Process (Hydrogen Peroxide from H2 and O2) coupled with Hydrazine production (Hydrazine, not coincidentally, is also the main substrate for the production of some of the most common Hypergolic fuels, such as UDMH, MMH, and Aerozine; which only need to be combined with N2O4 to burn) can be used to make more advanced and easily stored fuels for RealFuels mod to use... Both Oxygen (in the form of CO2) and Nitrogen (in the form of atmospheric HNO3, and likely, vast subsurface deposits) are readily available on Mars. So, in that environment, it's possible to produce anything that's made of Carbon, Nitrogen, and Oxygen (and a little Hydrogen- which is confirmed to be present on Mars, and theorized to be indicative of subsurface ice deposits). Duna is, of course, KSP's Mars analog, so the same should hold there... http://beamartian.jpl.nasa.gov/towhnall/question/15076/is-there-nitrogen-on-mars http://yly-mac.gps.caltech.edu/Reprintsyly/A_RecentPapers/Boxe%20et%20al%202012.pdf http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=191609 Keep in mind that "readily available" is a RELATIVE term- the atmosphere on Mars is rather thin, and obtaining high concentrations of any of these elements without long periods of atmospheric filtration and cryogenic storage (much more easily done than you might think) would require digging down into the Martian soil/subsurface... Duna's atmosphere is quite a bit thicker, however, so atmospheric filtration should be more practical there. The Moon (Luna) also has large deposits of Nitrogen (regolith air bubbles), Aluminum, Oxygen (Aluminum Oxides), Argon (regolith air bubbles), and even a little Carbon (graphite), Hydrogen (water ice in polar craters), and Xenon (regolith air bubbles) in its regolith/craters... So the "Mun" analog in KSP could be assumed to have minable deposits of those as well... This may all seem like a tangent, but it's NOT. What I'm pointing out is that there are MAJOR opportunities for expansion of the KSP-Interstellar ISRU system, which is currently only limited to the best-known of the possible ISRU processes (such as water-harvesting from ice on the Mun's poles and in the soil of Mars...) ESPECIALLY when RealFuels is also installed. Water is important for life-support and all, but the best FUELS that can be produced from ISRU are actually those that are Hypergolic- since they don't require cryogenic temperatures and can be stored for long periods of time without boil-off (unlike LiquidHydrogen or LiquidOxygen). They also have the highest fuel-density of common chemical propellant mixes, meaning you need the lowest tank mass/volume for a given amount of Delta-V (the ISP is lower, however, which makes them suboptimal for the upper stages of high Delta-V voyages... That being said, Hypergolics were actually what they used on the Apollo Service and Lander Modules- due to their high density and easy storage...) Their main/only disadvantage is that many of them are highly toxic in sufficient concentrations, and could potentially poison astronauts in the case of a leak... (as actually *DID* happen with the N2O4 during one Apollo mission- resulting in several hospitalizations) Adding reactions to produce Kerosene (Reverse Water Gas Shift Reaction followed by the Fischer-Tropsch Reaction) or Hypergolics (Anthraquinone Process --> Hydrazine Production --> Hydrazine methylation with locally-made formaldehyde to produce UDMH/MMH/Aerozine) would be a particularly valuable addition to a RealFuels/KSP-Interstellar integration config: right now the only way to produce Hypergolics through ISRU is through Karbonite's RealFuels Integration Config... http://en.wikipedia.org/wiki/Unsymmetrical_dimethylhydrazine http://en.wikipedia.org/wiki/Aerozine_50 http://en.wikipedia.org/wiki/Monomethylhydrazine Finally, note that MMH is just single-methylated Hydrazine, UDMH is di-methylated (double-methylated) Hydrazine, and Aerozine is a mixture (usually 50/50 or 70/30) of Hydrazine and UDMH... Regards, Northstar

IF you copy tree.cfg into the SAVE directly, it should work. Right? Right???? Regards, Northstar

@Ferram4 As one of the people who successfully ran KSP 0.24.2 without any issues whatsoever (aside from with context menus), I was disappointed to see how unstable the 0.25 build was (I kept getting crashes every time KSP loaded up). I can understand why you wouldn't want to try and support FAR on such an unstable platform. But, hopefully, you'll keep an eye on it to see if it gets any more stable for x64 in future versions? It's got to improve *eventually*- Unity is constantly evolving and changing, and sooner or later Squad's got to update to a more recent version of Unity as the basis for the game... Maybe that version of Unity might actually work perfectly with Windows x64. As a player with experience using Linux, I *strongly* recommend installing Ubuntu or another free version of Linux in parallel to Windows i your computer can handle it. If not (like with my current laptop- which I think would explode under the extra strain for having two OS' installed), then just wait patiently until x64 becomes stable agian in a future build, and play x32 until then. Hopefully we can convince Squad to update Unity when that time comes... Regards, Northstar