Northstar1989

I know. And that's not a gravity turn. It's just... stupid. A *REAL* gravity turn should be begun much more gradually, and increase in small increments as the rocket climbs: i.e. 90 degrees up --> 86 degrees --> 80 degrees --> 72 degrees --> 60 degrees --> 48 degrees --> 34 degrees --> 20 degrees --> 10 degrees --> 2 degrees etc... Note the DECREASE in the rate of turn at the very end. This should *always* be performed towards to the end to avoid overshooting the horizontal, and aiming too far below the horizon... Indeed. You *could*. But it's more worthwhile at this point to continue using the sustainment engine from the middle stage than to drop that stage... You want to have your upper stage be as light as possible- which means small engines AND fuel tanks... Most players (including even myself at times) make the mistake of having an under-engineered sustainment stage, and an overly-large upper stage relative to the size of their rocket... The MAJOR exception to this rule being if the upper stage is an orbital tug for something much heavier, or an Asteroid Redirect Mission... *OR*, you could just make the final part of the gravity turn quickly and early enough. Just as most players begin their gravity turn much too late and much too sharply, they also make the final part of their gravity turn much too late and don't level out quickly enough. By about 38000 meters, you should be burning straight horizontally. It should also be noted that there is often significant advantage in aiming for a higher orbit than 72 km x 72 km or something like that... While it will take more Delta-V *from the launchpad* to reach a higher orbit (say 250 or 350 km), it leaves room for phasing orbits for orbital rendezvous *UNDERNEATH* whatever heavy payload you're launching to orbit (space station, interplanetary mission, etc.), rather than above- which enables fuel tankers to reach your payload without having to waste a large amount of fuel phasing at a higher orbit... It also takes less Delta-V from the parknig orbit for interplanetary transfers *IF YOU USE A MUNAR GRAVITY ASSIST*, if you depart from a slightly higher orbit... That's because your Delta-V for a transfer hits a "sweet spot" based on the size of the ejection burn. If the ejection burn is shorter (less Delta-V) due to use of a Munar gravity-assist, then your parking orbit should be higher. A higher parknig orbit also safely lets you make an accurate/precise ejection burn with a lower TWR- which allows you to save on engine mass (thus increasing your rocket's Delta-V budget). Regards, Northstar

Actually, the United States' national debt is MUCH smaller compared to its GDP and population in comparison to, say, Italy or France. And a lot of space program funding actually ends up feeding back into the economy- as the profit margins and salaries are very high in the defense and space sectors (which also creates room to cut out a lot of fat if politicians can make up their mind to try and bring down costs...) And who do you think owns most of that debt? It's the Chinese, actually- which comes seriously in handy for preventing future wars and encouraging good relations between the US and China (China knows if they ever ended up at war with us, they would never see a cent of that money...) Regards, Northstar

We can do it intelligently and reliably if we start NOW- it's just going to take some serious funding... Honestly, the best thing would be for NASA to cooperate HEAVILY for financial and technological/engineering support with the ESA on this, and portray it to the public/politicians as a triumph of Western innovative spirit and intellectual freedom over the oppressive forces of Communism (China) or corrupt "democracies" really run by totalitarian leaders (Russia). Regards, Northstar

We seem to have no trouble preventing Hydrogen from passing through solid aluminum cans on Earth; or O2 supplies from outgassing from the ISS. Why would fuel storage in space space be any different? For the matter of using propellants with lower vapor pressures (don't forget that even RP-1 undergoes limited evaporation at STP), we're going to have to move to them eventually anyways. It's only a matter of time before to get anything truly useful done in space (such as setting up robotic ISRU infrastructure on the Moon and Mars), we're going to have to rely at least in part on orbital fuel depots to move our heavier payloads... We should be focusing more on technologies and design solutions for orbital fuel storage, ISRU, and propulsion technologies in the present- rather than sending robotic probes for Planetary Sciences. It's only so long that you can analyze a planet with sensors and rovers before you start running out of useful things to learn with unmanned missions... Eventually, we're going to have to start paving the way for manned interplanetary exploration, investigation, and colonization... (with a particular focus on ISRU, reusable launch systems, and colony self-sufficiency to bring down long-term costs...) Regards, Northstar

The danger with focusing on reaching "scope complete" is that they will abandon many useful or necessary features in order to get there, and because they feel the need for optimizations and bugfixes breathing down their neck... If, on the other hand, they get many of the optimizations and bugfixes done first, then they feel a lot less pressure to an arbitrary line with features. So, counter-intuitively, focusing on bugfixes and optimizations early on actually leads to *MORE* features in the final product... Regards, Northstar

It would be nice if, before they added Mk3 internals, they fixed the Mk3 cockpit's offset from normal 2.5 meter attachment nodes (causing it to hang below the main fuselage of spaceplanes in a weird sort of way...) Actually, I think they could take a serious page out of B9 Aerospace's book, and redo a lot of the spaceplane parts entirely to be bigger and heavier... Coupled with a procedural/stretchy system for generating fuel tanks and even structural fuselages, and wings, they could actually REDUCE the total number of parts in the stock game, while simultaneously giving a lot of heavier spaceplane and rocketry tech the "Stockization" treatment... Currently spaceplanes are far too lightweight/small and buggy in the stock game. Building large wings out of 50 parts each (which by necessity forces design of smaller spaceplanes), when they could easily be created out of a single "Stockized" procedural wing part, and having Mk3 cockpits that have a screwy offset from other 2.5 meter parts doesn't help with either point... I would like to see a day where, with both spaceplanes and rockets, players don't need to make use of 120 stock parts to build heavy lifters- they can build the same designs with 40 or 50 parts... (easily possible with "Stockization" of some of the features in the Procedural Parts and Procedural Dynamics mods...) This would make the game run a LOT smoother for most players, and could be balanced budget-wise by making larger procedural parts cost more money... Regards, Northstar

I just *DEMONSTRATED* that's not true to you with a working, economical Scrapper Ship system I have been using *FOR THE PAST 6 MONTHS*, and yet still you insist on that assertion. Are you mad, man? Insanity and faith/religion are the only possible explanations I can think of for denying a fact when it's starting you right in the face... Regards, Northstar

Stock aerodynamics.

Yes, the explosive airburst or impact force is also based on the composition. Metallic asteroids (only approximately 8% of all asteroids) are *MUCH* more dangerous (as they are more than twice as dense), for instance. The figure I gave in the footnote for the explosive force in the lower atmosphere (not the asteroid's kinetic energy at atmospheric re-entry, which is higher) of a 100-meter asteroid was based on the density of an average rocky asteroid, according to Wikipedia... A metallic asteroid would be a LOT more than twice as deadly relative to its volume! (due to its higher density, it would experience less drag relative to its mass...) Regards, Northstar P.S. Based on the decreases in the surface area exposed to drag with increasing size, and relative to mass with metallic asteroids, it appears that moderately-large metallic asteroids actually could easily reproduce the kind of spectacular flames in the lower atmosphere for a meteor that are normally only seen in Hollywood and fiction... (We also see flames like these during re-entry of smaller asteroids, most of them the size of grains of sand, in meteor showers... However they only flame like this in the uppermost reaches of the atmosphere- due to their small size they either burn up or slow down long before reaching the lower atmosphere...)

Haha, yeah- something like that came to my mind too... And you posted your reply before I fixed a math fail in my calculations- see the fixed estimate of how tall a Kerbal would stand on Earth! (7 meters tall, not 3!) Regards, Northstar

I know this may actually seem counter-intuitive, considering their small size, but Kerbals are actually giants compared to their environment... I was doing some math to try and figure out estimated worst-case scenario casualties from a direct impact of a Class C asteroid into Kerbin (as luck would have it, one of the first asteroids I ever tracked turned out to be a Class C on a 60-90 degree re-entry collision course entering Kerbin's SOI in about 57 days...) To do this, I actually had to figure out what Kerbal population densities might be relative to Earth's, based on their physical stature in regards to their planetary radius. And, as it turns out, Kerbals are HUGE... Some numbers I was working with: - The Kerbol system (Kerbin and the other planets) is a bit less than 1/10th scale the real solar system. Kerbin has a radius of 600 km, whereas Earth has a radius of 6,353 km) - Stock Parts, are at 64% scale of their real-world counterparts. The Kerbals themselves, however, only stand at about 0.75 meters tall according to the Wiki- which means there are 42.23% the height of the average American male in his twenties (177.6 cm), for a comparison. So, rounding down a bit as Americans are a little taller than the average human (due in large part to the average height in Asia), let's say Kerbals are about 40% the size of a modern-day human male... Therefore, Kerbals are a bit over FOUR TIMES the size of a human relative to his environment! If a Kerbal were scaled to Earth, he would stand over 7 meters (22.97 feer) tall! This meant for my asteroid-impact casualty-estimates, I needed to divide casualties by 2.5- as larger creatures have lower population densities... It also mean though, that despite Kerbals appearing cute and tiny, they are actually HUGE compared to their environment! Regards, Northstar P.S. Oh, and by the way, applying the 10x scale to a Class C asteroid, you get a 70-100 meter asteroid instead of a 7-10 meter asteroid. The Tunguska asteroid was in this size range (60- 190 meters according to Wikipedia, http://en.wikipedia.org/wiki/Tunguska_event), and it wiped out trees over a land area of more than 2,150 sq. km! It also entered the atmosphere by a *VERY* shallow re-entry trajectory, and so its explosive force when it airburst was "only" that of 10-15 Megatons of TNT, instead of the average of 38 Megatons for an 100-meter asteroid entering at a 45-degree angle (http://en.wikipedia.org/wiki/Asteroid_impact#Frequency_and_risk). You might want to re-think just how "harmless" a Class C asteroid is next time you see one hurtling towards Kerbin! P.P.S. With the laughingstock that is the current aerodynamics model, asteroids of any size aren't actually that dangerous- since drag exerted on them scales with their mass instead of their cross-sectional area in the stock model. If you're running FAR on the other hand, the larger asteroids should be able to reach the lower atmosphere at realistically enormous speeds, as big spheres of rock have very little cross-sectional area compared to their mass... With FAR, asteroids also become exponentially more dangerous as their size increases, like in real life- as the larger ones experience a lot less drag from the atmosphere relative to their mass...

Actually, and I say this more for the OP's sake than anyone else, that's a *TERRIBLE* TWR to have. You ALMOST NEVER want to go *that low* on your TWR. The penalty for doing so, in terms of Delta-V to orbit, is *much* higher than the drag penalty for going up at a TWR that's a bit too high... I actually wrote quite a bit on this once in an early thread, but the ideal TWR isn't 2 all the way up either... You want a TWR that is AS HIGH AS SANELY POSSIBLE until you almost reach terminal velocity from liftoff (this doesn't take very long to reach, and stock SRB's last quite a long time- so it's actually best achieved as a compromise, with a liftoff TWR of between 2.2 and 2.4), followed by a TWR a little bit *below* 2 for a period of time as you climb straight up, as any steering losses or tail fins on your rocket will reduce ideal TWR. TWR should continue to rise again as you gain speed after dumping your initial SRB's (use drop tanks that were attached to the SRB's to accelerate the rise of TWR if possible- a full rocket gains TWR proportionally faster than one with extra tank mass...) Once you start your gravity turn (which should be started low, and be carried out gently/slowly), ideal TWR begins to drop off again as your path length through the atmosphere lengthens, and your climb rate begins to eventually fall off a bit- but then rises again as the atmosphere becomes thin enough that these factors cease to matter as terminal velocity becomes impossibly high (by a bit over 35,000 meters, terminal velocity is, in fact, higher than orbital velocity at that altitude). If, AT ANY POINT, your rely on active turbojet or RAPIER engines in atmospheric mode in any part of your launch platform, you ideal TWR goes *DOWN*. This is because these engines have a velocity curve- which means thrust and ISP both decrease with increasing speed- and the air intakes necessary to use them also generate a LOT of drag at high speeds... (their drag coefficient increases with speed, up to a maximum value of 3.0) If you use ion or NERVA engines (or their more realistic KSP-Interstellar equivalents: called "plasma thrusters" and "thermal rockets", but which are actually the same technology in real life, but more realsitically/accurately balanced in-game) in-atmosphere in order to bring up your rocket's TWR during ascent (by utilizing upper-stage engines early- which is actually a good strategy for decreasing the fuel requirements and increasing the payload fraction of any launch...), then your ideal TWR goes UP, as these engines increase in ISP *very rapidly* as the atmosphere around them thins... One last thing- and this isn't about rocket TWR. I noticed your design has a *LOT* of Monopropellant aboard... This is generally one of the most common mistakes among KSP players- especially new players (I used to do it all the time myself). You don't need that much Monopropellent for your missions normally. Ideally, you want your Monopropellent supply to run out just as you are finishing the mission's very last RCS maneuver. I'm guessing you have 7, 8, or even 9 times more RCS fuel than you need in that rocket, unless you are *VERY* inefficient with your use of RCS... You can save a LOT of extra mass by cutting down on RCS- generally a couple radial tanks will suffice. Also, you don't necessarily need any RCS at all on most rockets- even if it is going to dock with a fuel tanker (I prefer use of KAS instead, as I can almost always get close enough with tiny rocket engine maneuvers alone to use the winches for fuel transfer- eliminating my need for RCS thrusters and Monopropellent entirely...) It is almost always more advantageous and fuel-efficient to dock the lighter craft with the heavier craft during docking- and in 90% of cases your fuel tanker should be the lighter craft of the two... (it should contain, at most, just enough fuel to refill your mission vessel, plus a tiny bit of extra fuel to de-orbit it so you don't leave debris...) Your tanker should be much lighter due to its lack of any payload, so it should do all the maneuvering to get into position for docking, while your mission vessel remains entirely motionless (other than possibly some gently torquing of your mission vessel with SAS wheels...) Regards, Northstar P.S. I'm glad some of these players were already to help you get your payloads to orbit. Always remember to give "Reputation" points to players who gave answers to your questions you found helpful... (when they took the time to answer your "Question" thread) You can do this with the star-shaped button in the lower-left corner of a player's post...

This simply HAS TO happen... Let's see, the facts: - This set of planetary alignments happens less than once every 100 years - The sun will be in the middle of a solar minimum (once every 3 years) - The sun is starting to go a potentially long-term (decades or centuries) increase in the amount of cosmic (extrasolar) radiation it allows to penetrate this close to it- which will SIGNIFICANTLY increase radiation exposure during interplanetary missions further off than 2021. This change could possibly be permanent, according to some scientists... So, we won't see another opportunity like this for at least a couple centuries- possibly longer if the solar minimum doesn't line up next time- and there might be higher levels of radiation to contend with when we do... It sounds like now is the best chance we're going to get to launch a mission like this, pretty much EVER. The scientific benefits maybe be... questionable. But the space race it could set off- that would be immensely useful to the future of space exploration. We probably wouldn't have *ever* left LEO if not for the Space Race (politicians would have been forever calling it too risky and expensive) IMHO... Regards, Northstar

Also, could somebody explain outgassing to me? I still don't understand it... How can you have loss of a propellent from a sealed fuel tank? Even if a stored liquid turns into a gas, in a closed container, that gas should just stay in place, and accumulate until the increased partial pressure of that liquid prevents further evaporation... How are you losing mass from a sealed container, without any reactions occurring inside? Doesn't that violate the laws of physics? I guess the containers must not be so tightly sealed- but in that case, isn't the solution just to create an airtight seal on the tanks, and make sure the tank walls can withstand the pressure of the vapors at thermodynamic equilibrium? Regards, Northstar

Don't forget that, with a NTR, lower ISP means higher thrust... You can also store a greater mass of denser gasses, such as Nitrogen (N2) or Carbon Dioxide, in the same tank volume under the same pressure- which reduces the Dry Mass of your rocket... Now if only I could convince FractalUK (the KSP-Interstewllar mod creator) to go an include CO2 and N2 as harvestable/storable resources, and allow their use in KSP-I's NTR's... (go bug him to do so for me, if you want to help me out- more voices have a better chance of being heard than just one...) Regards, Northstar

Also: I'm not saying they shouldn't do anything about stuff like the lack of IVA's, the "Precooler" parts that don't-actually-do-anything other than add deadweight to your spaceplanes, or the need to add more planets or re-balance many stock parts (like the NERVA's, as I mentioned before- which aren't OP'd compared to real life- until you consider they require absolutely no heat radiators...) Only that those changes should take a lower priority than *BIG* things like massively improving the running-joke aerodynamics module (in fact, the current model ought to be thrown out the window entirely, burned and trampled upon, and used as a doggie chew-toy - and then the aerodynamics model rebuilt from the ground up to resemble something like FAR...), or actually adding budgets (which is, thankfully, what they're doing now...) Regards, Northstar

I'll give my 2 cents here real quickly, and then move on to other things, because I have an asteroid redirect mission design process waiting for me in the game (which is currently open/running in background- it doesn't hurt to let my interplanetary transfer inch towards their destinations while I write...) First of all, I'm perfectly happy with the PACE of development. It's good for Squad to take its time to get things right, no arguments there. However I *AM* worried that some absolutely necessary features will get left by the wayside, or relegated to the realm of mods, given the current development pattern... Improved aerodynamics, resources, and (this isn't even on their list- but it absolutely should be) a procedural way to generate fuel tanks and wings to improve design flexibility, and reduce the clutter and catalog size of existing stock fuel tanks and wing parts, all feature highly on this list... On the last of those- it's already been proven through mods that parameters of procedural parts can be limited by tech tree progression, to prevent this breaking Career mode... The system currently being developed by "Procedural Parts" mod should *STRONGLY* be considered for "Stockization", as should an aerodynamics module similar to FAR for the basis of the new aerodynamics system, and some of the ISRU concepts from mods such as KSP-Interstellar for a resources system... I'm not whining for feature after feature. In fact, if they delivered the promised features for 0.24 (Contracts and Budgets), implemented these three features, and delivered a sound and smoothly-working multiplayer and science system, I wouldn't have much to complain about (that wouldn't stop me from still hoping for further improvements as icing on the cake- this game has a LOT of still-unmet potential...)- except for a need for code optimizations and bugfixes of course... If I were to really look far ahead, I would say they could also do with re-working the NERVA engines into something a bit more balanced (possibly with the need for extra parts for heat management) and actually resembling a real nuclear thermal rocket (which is what they actually are in real life), and throwing in a few more planets- but none of that is critical, and the game could even do without those improvements- even if I think including them *highly* advisable... I haven't been around long enough to see the earliest versions of KSP (I came in during 0.20.2), so I couldn't comment on how the pattern of updates has changed from the past; however I HAVE seen a change in Squad's latitudes towards the future of KSP. It seems like as time goes on, their goals keep becoming less and less ambitious, despite the continually-expanding player base... With the exception of announcing multiplayer (which I know is HUGE), what new *big* features have they announced plans for recently? I can't remember any in 10 months I've been playing KSP... They created the game, so they should have bigger and more creative ideas than the players, right? On the other hand, I haven't seen many optimizations since the 0.21 update less than a week after I downloaded the game for the first time- most updates since have been dedicated to implementing what I understand were already-planned features. So let me get this straight- they focus on adding planned features, but don't announce nay new ones except multiplayer for further ahead? And they don't do many bugfixes/optimizations either? It seems like they're toning DOWN their ambitions when they should be toning them UP given KSP's runaway sales success... Regards, Northstar P.S. I can understand the dangers of becoming the "Indie game that never gets finished"- but that trap often results from the extremely limited resources available to Indie development teams... At this point, given KSP's sales figures, Squad should have resources available for this game closer to the level of a small development studio that's turned out a number of games... They can raise their prices even further as time goes on if they have to in order to hire more programmers for KSP without compromising their other goals- most gamers won't hesitate to purchase a game this great for a bit more $- especially since they're NOT engaging in any of the kind of filthy, dirty money-mongering that dominates major studios like SEGA, where every little feature (even ones that are half-baked and poorly-developed, or were already a locked part of the game at shipment, *cough* Total War: Rome II's "new" factions, *cough*...) costs you $5 or $10...

I was also thinking about asteroids a lot lately... (after in my ongoing Career save I discovered a Class C asteroid on a direct collision course with Kerbin in approx 58 days... As a fraction of Kerbin's diameter, that's the same relative size as the asteroid responsible for the Tunguska Event was relative to Earth...) @FractalUK What would be the possibility of adding limited harvestable quantities of water-ice to some asteroids? (you could represent it as "Water" if you re-named "LiquidWater", as ice is a form of water after all...) It's already being done in the "Asteroid Cities" mod- even if they didn't do a good job (in my opinion) with many of there other premises and balancing decisions, you could still how they implemented it in their code... It could be present in only a random subset of asteroids, rather than all asteroids, if you could figure out how to code that... (Asteroid Cities inaccurately makes all asteroids contain water) Regards, Northstar

After reading up on Universal Storage, utilizing its fuel cells to create "LiquidWater" would be inadvisable, even if KSP-I renamed its resource to "Water". This is because Universal Storage converts separate "Hydrogen" and "Oxygen" resources into Water and ElectricCharge- rather than the entirely more useful system of converting stock "LiquidFuel" and "Oxidizer" into "Water" and "ElectricCharge"- which would allow you to use the much more readily-available and widespread stock resources to create water, and was kind of the point of my suggestion... (additionally, KSP-I currently harvests LiquidFuel in places you harvest hydrogen, as the two are assumed to be the same thing- such as when harvesting from Jool's atmosphere with an Atmosphere Scoop...) Note that it would still be possible to run fuel cells off Kerosene and LOX, if that's what Universal Storage took LiquidFuel and Oxidizer to represent- one would simply produced Carbon Dioxide (which would be useful for a Sabatier Reactor- *nudge, nudge* FractalUK alongside the Water and ElectricCharge... Regards, Northstar

What about creating a pack and wedges for KSP-Interstellar resources? Specifically, LiquidMethane, Ammonia, Hydrogen Peroxide, and Lithium? It needs pointing out that KSP-Interstellar (probably accurately) assumes that LiquidFuel is actually liquid Hydrogen- since most real rocket upper stages use Hydrogen/LOX rocket engines. It also eliminates the need to have a separate "Hydrogen" resource (one just balances resource capacities to consider LiquidFuel's density), and enables the products of water (or in the case of KSP-Interstellar "LiquidWater"- though they should probably eventually change it to "Water" to allow crossover with other mods) electrolysis to be burned in stock and stock-like rocket engines... (whereas your "Hydrogen" and "Oxygen" resources cannot) I can understand if there is a desire not to follow KSP-I's convention of LiquidFuel representing liquid hydrogen, but it is a point to keep in mind if attempting to create a KSP-Interstellar crossover pack. Utilizing methane as "LiquidFuel" in this mod is also an unrealistic idea- in real life, rocket engines need to be specifically designed to burn Methane/LOX rather than Hydrogen/LOX or Kerosene/LOX... Regards, Northstar

Not only is it feasible to recycle orbital debris, but I've already actually done it in-game, and, posted it to this forum some time ago... (links and images below...) First Design- 6 months old: http://forum.kerbalspaceprogram.com/threads/57509-Kerbin-and-Beyond-a-Maturing-Space-Program?p=774155&viewfull=1#post774155 Latest Design- 2 months old: http://forum.kerbalspaceprogram.com/threads/57509-Kerbin-and-Beyond-a-Maturing-Space-Program?p=1051518&viewfull=1#post1051518 I used the "Recycling Bin" part from Extraplanetary Launchpads, as well as RocketParts storage modules from Orbital Contsruction Re-Redux (due to their higher storage capacities than any of the RocketParts storage parts in Extraplanetary Launchpads- though I find the OCRR parts can store unrealsitically large masses relative to their volume. Ideally, I would like it if there were an extension to ProceduralParts that let me store lots of RocketParts in HUGE containers...) I use the salvaged RocketParts to, in turn, build things in orbit (like solar farms, modular components for moon-bases, Kethane scanning-satellites, probes, bigger space stations, tankers, and enormous interplanetary vessels to give some possible examples...) The economics are a bit low-margin, and require use of a stock NERVA engine or better (I used stock NERVA for simplicity, but better ISP can be obtained with KSP-Interstellar or NearFuture mods- with a bit more infrastructure...) What I basically would do is rendezvous with each and every piece of debris I wanted to recycle, and then fly at it at VERY slow speeds (under 5 m/s for safety) with the Recycling Bin active... This would recycle the debris into an equivalent mass of leftover fuel (if nay were present) and RocketParts- usually at 100% efficiency, although occasionally I experienced bugs where a craft were recycled and did not give me any RocketParts (I consider this realistic since real-life recycling would not be 100% efficient). What makes this worthwhile economically is that it takes a ENORMOUS amount of energy (fuel) just to get something into low orbit. It takes an *EVEN MORE* ungodly amount of energy (fuel) to get something to an even higher-energy position, like Low Munar (or Lunar, IRL) Orbit, or worse yet, around Duna/Mars or Jool/Jupiter... Therefore, every single kilogram you can avoid having to ship into orbit (by re-using mass already in orbit) pays for itself with interest- usually it costs a lot less fuel to get the fuel to orbit to rendezvous with a LARGE/MASSIVE/HIGHLY USEFUL piece of debris in orbit (relative to the size of the Scrapper Ship/tug- the more massive the scrapper ship, the more massive/useful the piece of debris has to be to be worth chasing) than it does to ship an equivalent mass to orbit. The economics improve (both in-game, and would in real-life) the more infrastructure you have in place to support your scrapping operations. I.E. if your Scrapper Ship is powered by a Microwave Beamed Power Satellite that feeds a Thermal Receiver on the Scrapper Ship used for thermal rocketry, your scrapper ship can get more Delta-V from a given fuel mass, and thus spends less fuel harvesting the same debris... If your fuel is produced off-planet through In-Situ Resource Utilization (such as from electrolyzing water-ice or regolith on the Mun/Luna for Hydrogen-Oxygen mix or combustible ratios of Alumina and Oxidizer...), you don't even have to ship any fuel to orbit for the recycling operations, and the operations become *MUCH* more worthwhile. (Essentially, for the beamed power bit, you heat up a specially-designed heating-coil with large amounts of beamed microwave power from a solar farm or nuclear nuclear reactor on in a stable orbit or on the ground of a planetary body or moon, and passing propellant over the heat, use the thermal expansion of the propellant for high-ISP propulsion, and high thrust with enough beamed power, without any of the mass for energy-generation having to be located on the ship. A variety of propellants can be used in a thermal rocket, including Water, Methane, Liquid Hydrogen, LFO mix- which can be combusted as well as heated by the thermal receiver for additional thrust/ISP, Ammonia, and potentially harvested/stored atmospheric gasses from Kerbin/Earth and Mars/Duna using Thermal Turbojet nozzles in-game...) Obviously, in real-life (and if running a Life Support mod in the game), without a supporting greenhouse module on a nearby space station to process wastewater, CO2, and fecal matter back into Oxygen, potable water, and food; you really ought to run such a scrapper ship as an unmanned drone. Even with no need to ship up supplies for crew life-support, such a scrapper ship is best run unmanned due to the slow/monotonous nature of the work and high radiation exposure to cosmic rays when performing such operations in higher orbits... In the version I utilized in my game, there was a single Service Module which could hold a crew member, which allowed me to use KAS winches just to drain leftover fuel rather than recycling the entire piece of debris (using any KAS ports already on the debris, or "drilling" an access port into the duel tanks through attaching a KAS port by KAS' EVA minor construction functionality...), or to pull individual components off the debris via EVA that could be removed with KAS, such as External Command Seats, Ox-STAT solar panels, and the smallest stock radial batteries... Torn-off parts could either be re-used on another ship, or recycled individually rather than recycling the entire ship. It should also be noted that recycling the ship with the Recyclnig Bin would automatically deposit any leftover fuel in the scrapper ship's fuel tanks... My scrapper ships were all designed before the 0.23.5 update. With the update, it might be more "realistic" (and with *extremely* large pieces of debris that would require MASSIVE storage modules to store all the resources from recycling the debris on-the-spot inside the ship, more mass-efficient) to actually grab onto debris with the "Claw", and haul them back to a space station (I regularly drop off salvaged RocketParts at a space station anyways- to avoid wasting fuel hauling them all over the place to future scrapping operations), where I could feed them to a Recycling Bin there instead of on the ship, and assume from a role-playing perspective that the debris would be more tied down and more slowly/carefully disassembled and recycled by either crew or remote-controlled robots, rather than magically being instantly processed into "RocketParts" that could be stored inside the ship by the Recycling Bin... Once again, the economics do work, both in real-life and in-game. The technology is feasible (though obviously IRL it would take a bit of engineering to adapt salvaging techniques developed for things like sunken ships to space). And I've actually *DONE IT ALREADY* in-game. So, everybody else, no more calling it "impossible", or "useless", alright? Regards, Northstar

Good point. I wasn't aware of that until your post. Could you provide a link to the post on fuel cells on the Universal Storage mod thread? A quick skimming of the OP there didn't reveal anything about it including Hydrogen-Oxygen fuel cells (although I might have been looking at the wrong thread- the one I saw looked more like a WIP dev blog...) @FractalUK What are the chances of convincing you to rename all "LiquidWater" as "Water", to be compatible with the Universal Storage mod and TAC Life Support? Regards, Northstar

@FractalUK I wanted to add in one other idea, but separate it into a different post, as I am less sure as to its scientific plausibility than in passing cyrogenically-stored CO2 through a nuclear thermal rocket (which all research indicates should be possible). What of the possibility of harvesting and storing atmospheric Nitrogen (as N2, not as ammonia), and (this is the uncertain part) being able to use it as propellant for Plasma Thrusters, as well as for Thermal Rockets (the latter should be perfectly feasible from an engineering/scientific standpoint). This would also pave the way for being able to use LiquidNitrogen as a harvestable resource for the Haber Process, which could be transported to orbit and processed there, instead of having to refine it into Ammonia on-planet; and for players to be able to make use of atmosphere-skimmers in Kerbin's upper atmosphere to harvest both Oxidizer (already doable with the Atmospheric Scoop) and the new LiquidNitrogen, as well as trace amounts of LiquidFuel and LiquidMethane (trace amounts of both H2 and Methane can be found in Earth's atmosphere, although they are unstable in an Oxygen-rich atmosphere, and eventually slowly decay in the same reactions as they are "burned" in...) I suggest being able to harvest LiquidNitrogen mainly to increase the feasibility of atmosphere-skimmer type ships. Currently, such designs are not really feasible on Kerbin or most other planets; as too large a fraction of the atmosphere is unusable for it to be worthwhile (the Nitrogen in the atmosphere still creates drag, even if it cannot yet be used as propellant, for instance). Being able to use captured Nitrogen as a propellant would increase the feasibility of such skimmer ships everywhere- but especially on Kerbin. I was inspired by a real-life proposal to harvest Oxygen using a satellite in Earth's upper atmosphere, for combustion with Hydrogen shipped up from launch centers, as well as for life-support; that would rely on Nitrogen-capture and a Nitrogen ion engine/ plasma thruster to provide the thrust necessary to make up for drag, and would rely on beamed microwave power from solar satellites in higher orbits... (I wish I could remember where I read up online on this proposal...) Regards, Northstar

@FractalUK I'm glad to see you eventually incorporated the Haber Process before, and I've still got my fingers crossed for addition of the Reverse Water Gas Shift Reaction (for harvesting LiquidWater from any CO2-containing atmosphere, provided you have an adequate supply of LiquidFuel. The reaction again: H2 + CO2 --> CO + H2O) I would like to continue my suggestion from before of adding Hydrogen-Oxygen Fuel Cells, to allow players to convert LiquidFuel and Oxidizer into usable LiquidWater and ElectricCharge. Currently the only way to get ElectricCharge out of LFO mix is to burn it in a rocket engine with an alternator... I would also like to point you in the direction of another mod, which initially began as looking to add greenhouses to TAX Life Support, but recently has started looking into possibly using KSP-Interstellar for ISRU options to provide inputs for growing Food (namely for Water and CO2 harvesting). Is there any chance you could help them out with that? (advice/pointers on how to best use KSP-I code) http://forum.kerbalspaceprogram.com/threads/79603-0-2-35-CELSS-Greenhouse-%28TAC-Life-Support-Add-On-Version-0-1-beta%29 Last, but not least, I saw an interesting suggestion on that CELSS Greenhouse mod thread, which I would like to repeat here- and suggest be added to KSP-Interstellar as a base functionality (I take no credit for this idea, it is not my own) What if players were able to harvest *and store* CO2 using KSP-Interstellar atmosphere scoops? While this was specifically suggested on the CELSS Greenhouse mod thread as a way to harvest feedstock for greenhouse food production, and there discussed storing the CO2 in TAC Life Support modules, it could just as easily be utilized in KSP-Interstellar for several different purposes... I was thinking, first of all, CO2 (as a new cryogenically-stored LiquidCO2 resource) could be used in thermal rockets as a potential fuel. Possibly also is Plasma Thrusters... This would be useful for atmosphere-skimmer ships working off any CO2-containing upper atmosphere to harvest and store one more type of useful propellant. Currently, the only atmospheric gas that can currently be used in this way is Hydrogen (in the form of LiquidFuel), harvested from the atmosphere of Jool... Second, and more importantly, CO2 harvested in this way could be fed as feedstock into the existing pipeline of ISRU reactions- being usable for the Sabatier Reaction instead of the reaction having to be carried out in-atmosphere. This would enable small landers or atmospheric skimmer ships to feed inline refineries in a larger orbital mothership (itself incapable of entering the atmosphere or landing) with CO2, enabling a player to carry out the Sabatier Reaction in space. Even if CO2 (LiquidCO2) were not enabled as a propellant in and of itself, LiquidMethane and LiquidWater both would be. Further, players could always then electrolyze that LiquidWater for a higher-thrust solution than using LiquidWater in thermal rocket nozzles; and the ability to use the LiquidFuel component in Plasma Thrusters, and the Oxidizer component to combust the LiquidMethane in chemical (rather than nuclear) rockets. In short, a lot of interesting ISRU opportunities could be opened up simply by enabling players to harvest and store CO2 from CO2-containnig atmospheres, and use it as a feedstock into the Sabatier Reaction (which then would have to be added to inline refineries, in a version using LiquidCO2- and also preferable to the landable versions, under the same button if possible, to increase the flexibility of their potential usage...) Regards, Northstar

Absolutely. Cargo Throttle increases thrust by 50% (to 150% of Normal Throttle, the default) on all Firespitter propellers and helicopter rotors. It also increases electricity or fuel consumption by 50% as well- though due to the reduced thrust values propellers/rotors achieve at higher altitudes, they consume less fuel/electricity as your craft climbs, and thus Cargo Throttle shouldn't be a problem if your ElectricCharge budget is tight as long as you don't throttle up to maximum on Cargo Throttle at sea-level... I can understand not wanting to attempt night-landings, but I can't see the purpose in not wanting to fly on Duna at night at all. It shouldn't be a problem as long as you are flying above the highest mountains, as there is no risk of colliding into anything, and if you use Cargo Throttle I would guess your craft should be capable of climbing to 8500 meters- at least long enough to make a temporary/unsustainable climb to cruise over the highest peaks... Thanks. I've never tried using maps to guide any of my missions before (I generally like to look at the facts on the ground below and in front of me, rather than a map), but after seeing how ridiculously easy it is for everything to just blend into one giant, red blur on Duna at midday or at night, I might want to give the maps a try to find a good landing spot... I also hadn't thought of trying to get out and "push" on EVA- although I have realism qualms with that (real-life EVA packs can carry at most around 50 m/s Delta-V, in the case of NASA's retried MMU- *NOT* the 600 m/s of EVA packs in KSP...) The only problem with landing is, I need to find a spot with a *LONG* approach vector at low altitude, due to the Eagle's current difficulties turning (as well as climbing/diving) with the magical extra reactor fuel weight at the back. Right now, it has an *ungodly* turning radius (in fact, I haven't even tried turning it more than 50 degrees off its re-entry heading yet), so I'm not sure of the feasibility of a South Pole landing... I suspect I won't have nearly so many problems after I load some LFO mix, and possibly also some Hydrazine (Monopropellant) to the front service module. Although it might not perform as well as it was designed to, resulting from its increased weight and drag (since stock aerodynamics, unrealistically, make a full fuel tank have more drag than an empty one- if you repeated the famous/mythical experiment of dropping a wooden and an iron ball off the Leaning Tower, in KSP they would fall at the same rate...) it will still perform better than it's been doing so far... Regards, Northstar