Northstar1989

Where do you ever get the idea of a LASER launch system??? I never said lasers, I said *microwaves*. There's a BIG difference, because high-powered microwave beams are MUCH cheaper and more cost-effective... (they also suffer far less atmospheric absorption) There's also no need for miniaturization. Of the satellites, anyways. What I'm talking about is a launch system that can EASILY launch current-sized satellites. If FACT, Microwave Beamed Power systems work BETTER the more you scale them up, because a larger rocket has a larger thermal receiver as a target for the microwaves, and thus you don't have to focus the beam quite as well... You would have no issues launching humans with this system- in fact in many ways it could be safer to sit atop a Microwave Thermal Rocket than a chemical one, as there might only be a single fuel type and no oxidizer aboard (LOX *can* be used for an afterburning-effect if desired, to greatly increase thrust at the expense of a sizable hit to ISP, however...) and far fewer parts likely to fail... No, you wouldn't have an assortment of chemical rockets. If microwave beamed power were implemented on a sufficient scale, you wouldn't have need for them anymore... Microwave Thermal Rockets are still rockets. In fact, it's right in the name. I think you have a DRASTIC mis-understanding of how Microwave Thermal Rocketry actually works. Here is are two media articles I suggest you read to enlighten yourself: http://www.cnet.com/news/rocket-scientist-aims-to-relaunch-propulsion-technology/ http://nextbigfuture.com/2014/02/escape-dynamics-and-microwave-power.html And if you want more detail and scientific/engineering explanation, read this scientific paper from the Caltech library: http://authors.library.caltech.edu/3304/1/PARaipcp04b.pdf - - - Updated - - - The standard, often-cited figure is 10 km/s to LEO. 9 km/s is spent fighting gravity and gaining horizontal velocity+altitude, and 1 km/s is lost to atmospheric drag. Don't know why you brought that up though. And the figure varies GREATLY according to rocket size (larger rockets experience proportionately less drag due to the Square-Cube Law), TWR (slow ascenders experience less atmospheric drag), shape, and ascent profile. Not to mention spaceplanes- which would be one of the single best uses of Microwave Thermal Rocketry (because you could use the atmosphere for propellant in the beginning via Thermal Turbojets, and get off the ground and all the way to orbit with a TWR significantly less than 1) experience significantly more atmospheric drag than rockets... (but lose less Delta-V to gravity) Regards, Northstar

You're forgetting one critical thing. The Rocketdyne F-1 engine had an ISP of 263 seconds at sea level, whereas the Raptor would have an ISP of 321 sl (363 s vac), according to the current figures on Wikipedia (your source for the thrust figures). Plug that into the Rocket Equation, and you'll find you get a DRASTIC reduction in rocket mass. And that's BEFORE you consider that we can now achieve MUCH lower dry masses for the same payload thanks to numerous advances in materials science and composites since the 1960's... Regards, Northstar

What you're asking doesn't make any sense. There's already extensive proof that compressed (as a side-effect of pressurization) fuels have been used in space programs (especially with pressure-fed rocket engines). You want me to get inside the rocket designer's heads, and provide their logic for designing things the way they did? With some notable exceptions, a lot of that reasoning isn't exactly flaunted out in the open- only a few key reasons are given for any design choice. And like I said before, LH2-compression is a design trade-off: it comes at the cost of reduced mass-fractions (a CRITICAL design factor in upper stages). It's usually not even a worthwhile benefit for the increase in tank-mass: but is very important to simulate for a stage that is going to be highly-pressurized anyways (such as one attempting to re-create a real life rocket design with a pressure-fed upper stage). Just go and look up the compressibility factor of LH2 if you really want to see how compressible it is, by the way. First of all, sources on the #'s would be helpful. Second, did you even bother whipping out a calculator when you cited those #'s? That may SOUND like a low utilization, but that's actually 94% utilization- quite impressive really! EDIT: Calculations based on the Shuttle's External Fuel Tank volume and LH2 mass reveal only a 0.16% increase in fuel-density due to pressurization (based on a density of 70.85 kg/m^3 at STP. And it turns out the LH2 tank is pressurized at roughly 2 atm, rather than the average pressure of 1.5 atm for the whole EFT- as the LOX is much less pressurized...) So I guess I was wrong about the External Fuel Tank, entirely. Still doesn't mesh with the figures I've seen on LH2-compressibility, though... Perhaps the stated volume on Wikipedia includes the pressurant as well? (which would throw of ALL attempts to calculate how compressed the LH2 is...) The source page yields a 404 Page Not Found- so there is absolutely no way to figure out from the source what the Wikipedia figures actually refer to (the stated LH2 mass seems suspiciously low just based on expected increases in density from temperature alone, for instance, as STP is a *much* higher temperature than the LH2 tank's operating temperature...) - - - Updated - - - Not at all. More likely, you're overestimating how drastic I think the effect is. A 400% utilization at 40 atmospheres of pressure (a # I simply made up before) is 1/10th the fuel-density of an ideal fully-compressible liquid, for instance. And has 10x more fuel tank mass relative to fuel mass (40x tank mass but only 4x fuel mass) to boot! I never said that pressurization is some sort of magical cure-all, only that it's an important factor we need to accurately simulate (by allowing utilization to exceed 100% for highly-pressurized tanks. We're talking 2-digit atmospheres of pressurization here for very small increases in fuel-density...) Both chilling and pressurization increase utilization. Chilling increases thermal leakage into the tank (which ultimately drives boil-off) however, whereas pressurization actually reduces it (by requiring increases in the thickness of tank walls- thus improving the insulation provided by the tank walls themselves...) So they're different approaches with different consequences. That being said, chilling *IS* the much more mass-effective solution. Any real attempt to significantly increase LH2 fuel-density would almost certainly make use of both, with a *very strong* preference for chilling, however... (if you're using composite materials for the fuel tank, rather than steel or titanium, the tank material itself has reasonable insulative qualities if thick enough. So it makes some sense to pressurize so as to gain the extra insulation from the thicker tank, and reduce the burden on the turbopump if you're not using a pressure-fed engine to begin with... Honestly, chamber pressure and turbopump considerations are the only real motivations for LH2-pressurization...) That link has nothing to do with it. I'm intelligent enough to know the difference between gaseous hydrogen and LH2. I *suggest* you actually question your own assumptions before jumping to the conclusion that I must be wrong. You'll find plenty of evidence out there to support the fact that LH2 *is* indeed significantly compressible. A wise solution to increasing LH2-density? Probably not (the mass-penalties in tank-mass are enormous). But an important factor to simulate for stages that are already going to be highly-pressurized anyways (such as a service module attempting to re-create a real life pressure-fed stage). Regards, Northstar P.S. If you're wondering why chilling increases thermal leakage into the tank, it's because it reduces the surface temperature of the stage's outer skin (if tank temperature is reduced without a corresponding increase in insulation). This alters the balance of thermal energy leaving vs. entering the tank via thermal radiation. The temperature drop may seem small in further cooling LH2, but thermal radiation follows the Stefan-Boltzmann Law- radiation is controlled by the FOURTH power of temperature. So even a small drop in temperature means a relatively large drop in thermal radiation. The colder an object is in space, the faster in gains heat from the environment (even space can be thought of as having an ambient temperature, of sorts, due to the average levels of infrared radiation passing through it), the hotter it is the more slowly (and if heated to a sufficient temperature, any object will *lose* energy to its environment rather than gain it).

Interesting. But the TWR of later-generation NTR's reached as high as *30*, with much higher total thrust than NERVA as well. The Timberwind NTR designs, for instance, had the following design stats... (these were taken directly from the Wikipedia article) Timberwind 45 Diameter: 13.94 ft (4.25 m) Vacuum thrust: 99208 lbf (441.3 kN) Sea level thrust: 88305 lbf (392.8 kN) Vacuum specific impulse: 1000 s Sea level specific impulse: 890 s Engine mass: 3300 lb (1500 kg) Thrust to Weight Ratio: 30 Burn time: 449 s Propellants: Nuclear/LH2 Timberwind 75 Diameter: 5.67 ft (2.03 m) Vacuum thrust: 165347 lbf (735.5 kN) Sea level thrust: 147160 lbf (654.6 kN) Vacuum specific impulse: 1000 s Sea level specific impulse: 890 s Engine mass: 5500 lb (2500 kg) Thrust to Weight Ratio: 30 Burn time: 357 s Propellants: Nuclear/LH2 Timberwind 250 Diameter: 8.70 m (28.50 ft). Vacuum thrust: 2,451.6 kN (551,142 lbf). Sea level thrust: 1,912.300 kN (429,902 lbf) Vacuum specific impulse: 1,000 s. Sea level specific impulse: 780 s. Engine mass: 8,300 kg (18,200 lb). Thrust to Weight Ratio: 30 Burn time: 493 s Propellants: Nuclear/LH2 Even higher engine TWR's could have theoretically been achieved by replacing the LH2 with Methane... Regards, Northstar

@Boris I am a co-creator (honestly, Dreadicon did most of the coding) of a KSP-I/RealFuels integration config that worked back in 0.25, but I haven't had the opportunity to test for 0.90 yet due the KSP-Interstellar not being updated for 0.90 (I only *just* came across your work here). I was wondering if by switching from ORS to CRP if any of the resource names, or harvesting/conversion modules had changed. Any changes to either will break the config. My laptop is breaking down, and I haven't had the chance to switch over to the replacement yet, so it would also be AWESOME if someone (preferably experienced using RealFuels) were to test the config out by going and installing this updated version of KSP-I and the latest version of RealFuels in the same save (the integration config comes standard with RealFuels now). Also, I could use fresh set of eyes looking for potential problems... Regards, Northstar

OR, you could just increase the Funds rewards (the main limiting factor on progression- due to the cost of facility upgrades) through Custom difficulty instead of playing on Easy mode. Personally, I play on a Custom Difficulty every time- with a large bonus to starting cash and tweaks to Funds rewards/penalties based on whether I'm playing with Real Solar System (RSS rockets are much larger, and therefore more expensive- NECESSITATING an increase to Funds rewards for a reasonable progression rate...) Regards, Northstar P.S. Still working on getting that Flying Duna challenge done. I was making rapid progress towards it before, but then I accidentally corrupted my save, and on top of that my laptop began to fail soon after I started over (with RSS 6.4x and upscaled Funds rewards/penalties the second time around- though upscaling the Funds penalties commensurate to the rewards turned out to be a HUGE mistake as it increased facility upgrade costs as well, when my goal was FASTER progress). I've got a replacement laptop just today, but haven't even unpacked it yet... P.P.S. I've said this before, and I'll say it again- RSS scaled versions of Duna actually make landing a plane there easier, as it makes the landing sites proportionally larger... The extra Delta-V requirements don't bother me, as I've literally designed rockets that can send 100+ tons to Duna without refueling in the stock game before... (so getting a 10-ton plane there in RSS 6.4x is easily within my capabilities)

You problem boils down to this- you TWR is too high. That's why you're having problems with making speed too early. Simply pile a few more fuel tanks on the rocket. You'll increase your Delta-V budget AND reduce your TWR. Or, just use less powerful engines- but that's the less Kerbal solution. The cheapest way to complete this contract and still make orbit would be to just use the T-45 as the launch engine (activate and deactivate it with Action Groups so you can still activate it via staging), and add or subtract fuel tanks until you hit the correct TWR to hit speed *just* before you leave the altitude bracket. If you haven't unlocked action groups yet, then radial engines and/or a single Rt-10 SRB with an appropriate-sized (read: comparatively LARGE to the SRB) rocket placed on top of it will work... You will have to appropriately (read VERY small/light) size your payload to make orbit with nothing but a single RT-10 as your launch stage though (with a T-45 kicking in as a sustainer in the contract window). Regards, Northstar

I don't think you understand the point he is making. He is talking about mass-leveraging: using mass you bring to a destination (such as Mars) to make an even greater mass of fuel (or anything else, for that matter). If you bring along 4 tons of Hydrogen to Mars, you can convert it into 16 tons of Methane (the mass-leveraging factor is approximately 1:4) using the Sabatier Reaction with CO2 readily-available in the Martian atmosphere. Combine that with the fact that 80% of the mass of a Meth/LOX fuel mixture is Oxygen (more if you burn oxygen-rich), which can be electrolyzed from Martian CO2, and you end up with a 1:20 mass-leveraging ratio. All this is why he used the term "effective ISP" rather than the actual ISP on any engine you'd be utilziing. For what it's worth, Mars' atmosphere is also significantly rich in Argon- which could be utilized to run a VASIMR engine. If you wanted to get REALLY ambitious, you could start collecting THAT from the Martian atmosphere, and use it for your return-journey to Earth (of course, running a sufficiently powerful VASIMR thruster for a manned mission would almost certainly require an onboard nuclear reactor or Microwave Beamed Power). Regards, Northstar

I hate to necro an old thread, but this is still an interesting topic to discuss, and I feel it would be a huge waste to start over with an entirely new thread... So, any takers? Anyone have any more thoughts/ideas on this? I want to take this opportunity to add in a few new thoughts/pieces of information. First of all, not content to merely TALK about mass drivers, I went out and searched for a functional mod with them. Eventually, I was lucky enough to stumble across an old/outdated mod that had a working part (which wasn't broken by updates)- the Stanford Torus mod. I've went and re-released the Mass Accelerator parts from this mod in keeping with its open source/ open re-use license... (see the mod's pre-release thread for more details) Second, I wanted to ask about Electrodynamic Tethers. Supposedly, these are devices that can push off Earth's magnetic field using an electric current running through a rotating wire to generate force (the Earth acts as the reaction mass- but is moved very little due to its enormous size). Are these credible? Has anyone else here ever heard of them before? If they're real, I'd imagine maybe there would even be a way to exploit this on a smaller scale inside of a spacecraft to construct a vehicle that accelerated orbit purely by pushing off the Earth's magnetic field... It's not magic propulsion- there is still reaction mass (the planet itself), it's just not contained inside the spacecraft. Is there something I'm missing here. or would this actually be possible? I'd assume Microwave Beamed Power could be utilized to provide a sufficiently lightweight/dense power source to run such a propulsion system... Regards, Northstar

Raptor, I've seen you mention this several times, but I'm curious- where exactly are you getting mass/TWR figures for the NTR's? Are you using figures from the old, (comparatively) low-tech NERVA program, or are you using designs from the much more advanced Timberwind and BNTR (Bimodal Nuclear Thermal Rocket) programs? The Russians also continue to work on NTR designs under a veil of semi-secrecy, from what I've heard. And NASA has an entire team dedicated just to keeping older designs up-to-date with newer materials and minor engineering refinements. So it probably wouldn't be unreasonable to assume even lower masses than the ones from Timberwind or the BNTR programs for the most modern NTR designs... Regards, Northstar P.S. You may never have heard of Timberwind of the BNTR programs. The BNTR program, which also goes by other names, refers specifically to the US/Russian join-program in 1992-1993 referenced in this article and in one of the NASA Mars Design Reference Mission documents. Project Timberwind was a top-secret government program that was developed for the Star Wars program from 1987-1991 until it was shut down by an anti-nuclear whistleblower in 1992 (you may have even noticed me making snide remarks about said man, Steven Aftergood, and his overblown fears of nuclear rockets on certain threads on this forum...)

Great work Nebu! Perhaps I could convince you to release a version with Eeloo's orbit already fixed? I, and a lot of other players, really don't want to risk mucking around with the planetary orbits in the config files by hand... Also, would installing this over RSS and editing Eeloo's orbit apply retroactively to my current save? Or would it break it? (keep in mind I currently have no vessels outside Kerbin orbit). Would I have to start a new save to play with awesome 6.4x scale outer planets? Regards, Northstar

@Ferram4 So, I guess my praise/flattery/attempt to get you to approach Squad about helping overhaul aerodynamics (if you haven't already) went completely unnoticed? I really hope you'll give it a try. KSP could really use great work like yours in the stock game. Keep in mind they'll probably be willing to pay you for your work (as I understand it, this is what they've done with other modders like PorkJet). Probably not a ton, mind you (Squad's not exactly loaded), but every little bit helps, right? Regards, Northstar

How do you think the pressurization on a liquid fuel tank works, exactly? The pressurant gas itself never (or rather, isn't supposed to) enters the engines- the pressure is transmitted through the *liquids* (which, by the way, are initially pressurized in the fuel tanks of pressure-fed engines with high combustion chamber pressures- in those cases the pressurant is only used to *maintain* the initial pressure by replacing lost fuel, rather than to create it). Some liquids, such as water, are basically incompressible and will simply transmit this force, but other liquids will increase in density in response to pressure, and a few can even be compressed all the way to a solid state... Liquid Hydrogen, one of the most important cryogenic fuels, is known to be *particularly* compressible for a liquid. Like liquid CO2, it can be substantially compressed (unlike CO2, it is difficult to compress it all the way to a solid, as the melting point of Hydrogen is so low). If you don't believe me, I suggest you do a simple Google search for "liquid hydrogen compressibility". This means that fuel tank with LH2 under pressure *will* contain substantially more fuel mass than one at 1 atmosphere of pressure. I don't know off the top of my head how compressible N204, LOX, or any of the Hydrazine-derivatives (UDMH, MMH, Aerozine), but at least *some* liquid fuels/oxidizers are compressible to quite a substantial degree. Arguing about a basic fact of physics (that some liquids ARE compressible- LH2 in particular) distracts from my point. Pressurization enables masses of liquid to be stuffed into a tank greater than what could be achieved with 100% utilization at 1 atmosphere of pressure, thus *effective* utilization can greatly exceed 100% in highly-pressurized fuel tanks. (at least when the fuel tank contains a compressible liquid- such as LH2) Regards, Northstar - - - Updated - - - I hate to contradict you NathanKell, because your modding work is so brilliant and you clearly have a strong background in physics and some fields of engineering, but some liquid propellants *are* compressible. If you compress Liquid Hydrogen to hundreds of atmospheres when you first put it into the tank (this requires very powerful compressors), then you can easily fit *many* times more fuel mass into a tank of the same volume. It's no free lunch though- the tank mass scales with pressure in a pressure vessel (due to the requirement for thicker/stronger walls), and you end up getting an inferior fuel fraction in the tank (as 100 Liters of LH2 at 100 atmospheres pressure will contain less than 100 times the mass of fuel due to its compressibility factor). This is why most pressurized LH2 tanks are only pressurized at a few atmospheres of pressure (anywhere from 4-5 atm to as low as 1.5 atm for the Space Shuttle External Fuel Tank) if the goal is merely to reduce the volume of the fuel tanks (while holding the same fuel mass) rather than to feed a pressure-fed rocket engine. OK, so then this principle just needs to be extended to compressible LIQUID fuels (scaled accordingly for the fuel type- some liquids, such as LH2 or Liquid CO2 are highly compressible, while others such as Water are basically incompressible) to attain an accurate balance. Like I said before, this is one of the advantages of Service Modules- they can compress more fuel mass into a compact form. The downside is that they have an inferior mass fraction- which is already accurately accounted for in RealFuels. Regards, Northstar

@swamp_ig, NathanKell This is highly similar to a post I made on the RealFuels thread, but as it is an issue that is primarily of concern when both RealFuels and Procedural Parts are installed (although it also rears its head with combinations like NovaPunch2 + RealFuels), I thought I'd point it out again here... Procedural Parts currently fails to properly model pressurized fuel tanks. That is, stage types that could have fuel tanks sufficiently pressurized that their fuel volume capacity actually exceeds what could be held at 1 atmosphere of pressure, are never capable of holding more fuel mass/volume than what equates to 100% utilization at 1 atmosphere of pressure in Procedural Parts. This mainly holds true of Service Modules (which can reach an average utilization of 400%, 500% or more compared to tanks a 1 atmosphere- through high pressurization in real life), but also could be thought to apply to other tank types to a limited degree, as other tank types are often pressurized at a lower level (the Space Shuttle External Fuel Tank was pressurized to 1.5 atm, for instance) This mainly affects Service Module parts from the Procedural Parts mod, but also affects a few mod "Service Module" parts such as the NovaPunch2 "Yawmaster Service Module". All of these parts have MUCH lower volume capacities than they should for their size, as real life service modules often exceed 400% utilization (and can reach 500% or more) compared to 1 atm through highly pressurizing the fuel tanks. Even ordinary fuel tanks are often pressurized- the Space Shuttle External Fuel Tank was pressurized to 1.5 atm, for example... The mass of the fuel tanks should be scaled with the volume capacity- i.e. a Procedural Parts Service Module with 500% utilization should have slightly more than 5x the tank mass of a BalloonCryo tank of the same size (Service Module tanks are also insulated in Procedural Parts, and there doesn't seem to be a way to create Service Modules with uninsulated pressurized fuel tanks for hypergolic...) I say *more than* 5x the tank mass because service modules often include more structural mass than standard fuel tanks in real life (the Procedural Parts mod already accounts for this with an inferior mass-fraction). The primary advantage of service modules is that they hold a lot more fuel mass for their physical size due to pressurization (thus creating a much more compact aerodynamic profile with a higher ballistic-coefficient, or fitting inside smaller fairings, among other benefits) but strangely, this advantage is NOT reflected in the Procedural Parts- making them just heavy fuel tanks with inferior mass-ratios compared to all the other fuel tank types (they do have the capability to store ElectricCharge, but this is only a minor benefit for their much higher mass...) There is no easy way to simulate the other main benefit of pressurization in KSP besides a higher space utilization- the ability to efficiently use pressure-fed engines that are simpler/cheaper/lighter to design and manufacture compared to those relying on turbopumps... Regards, Northstar P.S. Turns out that fuel tanks are often even more highly pressurized than I thought. Any pressure-fed rocket engine requires *higher* tank pressure than chamber pressure, and the Kestrel pressure-fed rocket engine of the Falcon 1 had a chamber pressure of 930 kPa (9.18 atm), for instance. Which means, the fuel tanks of the Falcon 1 upper stage were pressurized to at least 930 kPa as well... P.P.S. Just a note for anyone trying to look up tank pressures on their own: often, the tank pressures must be devised by inference from the chamber pressures of pressure-fed engines (and is often not available at all for turbopump-fed engines). For some reason, space agencies aren't exactly eager to publicly share the pressure levels of the fuel tanks in their rockets...

Good insight as always. We're missing one MAJOR feature of real-world fuel tanks though (well, one more besides the problems I mentioned with how the Square-Cube Law affects boil-off before...) Pressurized Fuel Tanks. That is, stages that have fuel tanks sufficiently pressurized that their fuel volume capacity actually exceeds what could be held at 1 atmosphere of pressure. This mainly holds true of Service Modules (which can reach an average utilization of 400%, 500% or more compared to tanks a 1 atmosphere- through high pressurization), but also would likely hold true of spaceplane parts (although with the volume factors reaching as high as 13x the LFO capacity for existing spaceplane parts in KSP, it seems that a roughly 3 atm pressure level with less than 100% space utilization is already accounted for...) This mainly affects Service Module parts from the Procedural Parts mod, but also affects a few mod "Service Module" parts such as the NovaPunch2 "Yawmaster Service Module". All of these parts have MUCH lower volume capacities than they should for their size, as real life service modules often exceed 400% utilization (and can reach 500% or more) compared to 1 atm through highly pressurizing the fuel tanks. Even ordinary fuel tanks are often pressurized- the Space Shuttle External Fuel Tank was pressurized to 1.5 atm, for example... The mass of the fuel tanks should be scaled with the volume capacity- i.e. a Procedural Parts Service Module with 500% utilization should have slightly more than 5x the tank mass of a BalloonCryo tank of the same size (Service Module tanks are also insulated in Procedural Parts, and there doesn't seem to be a way to create Service Modules with uninsulated pressurized fuel tanks for hypergolic...) I say *more than* 5x the tank mass because service modules often include more structural mass than standard fuel tanks in real life (the Procedural Parts mod already accounts for this with an inferior mass-fraction). The primary advantage of service modules is that they hold a lot more fuel mass for their physical size due to pressurization (thus creating a much more compact aerodynamic profile with a higher ballistic-coefficient, or fitting inside smaller fairings, among other benefits) but strangely, this advantage is NOT reflected in the Procedural Parts or NovaPunch2 mods- making them just heavy fuel tanks with inferior mass-ratios compared to all the other fuel tank types (they do have the capability to store ElectricCharge, but this is only a minor benefit for their much higher mass...) There is no easy way to simulate the other main benefit of pressurization in KSP besides a higher space utilization- the ability to efficiently use pressure-fed engines that are simpler/cheaper/lighter to design and manufacture compared to those relying on turbopumps... Regards, Northstar P.S. Turns out that fuel tanks are often even more highly pressurized than I thought. Any pressure-fed rocket engine requires *higher* tank pressure than chamber pressure, and the Kestrel pressure-fed rocket engine of the Falcon 1 had a chamber pressure of 930 kPa (9.18 atm), for instance. Which means, the fuel tanks of the Falcon 1 upper stage were pressurized to at least 930 kPa as well...

But there are two mods that simulate N-body physics in KSP: http://forum.kerbalspaceprogram.com/threads/70881 http://forum.kerbalspaceprogram.com/threads/68502-WIP-Principia-N-Body-Gravitation-and-Better-Integrators-for-Kerbal-Space-Program Regards, Northstar

All my poor Kerbals are trapped on Kerbin- except one who is stuck in LKO. I dropped my laptop, and now it sounds like it wants to explode (leading me to immediately power it down) every time I try and run KSP... New laptop in the mail, to arrive SOON . But its specs are even worse than my current laptop (2 GB of RAM instead of 4 GB RAM, although it does have a significantly more powerful CPU...) Regards, Northstar

Which price is the base price? I don't really want to go and look up the payload of TESS right now and use that to back-calculate expected prices... Regards, Northstar

My laptop had a little bit of an accident (I dropped it), and now it's not really very capable of running KSP without going wacky (or even running without random crashes). So screenshots of daytime launches using the Mass Accelerators might take a little while (possibly until I get a replacement laptop). But, in the meantime, I still want to hear how this mod is working out for you guys. So feel free to post your progress reports here. Regards, Northstar

Hi Ferram, I'm sure you've heard this suggested over and over lately, but have you considered approaching Squad to see about having FAR included in the aerodynamics overhaul that is being (or will soon be) worked on for KSP? I think that your skill+experience and prior work on the KSP aerodynamics problem would go a LONG way towards helping Squad understand some of the choices they make with overhauling aerodynamics (I highly doubt anyone at Squad has much background in the subject). It might also be possible to convince them to include some or all the code from FAR, which would be awesome, as I think it's currently a GREAT solution for KSP's aerodynamics... Regards, Northstar

Is that really so ridiculous? If the vertical velocity is less than, say, 2 m/s, I would think it's entirely reasonable to "skip" off the surface of the water for an extended period of time... Water *is* softer and safer to land in than land at the same velocity in real life, and you can already land at 150 m/s on land in stock KSP... Also, have you considered approaching Squad to get this mod added to stock for future versions of KSP? I *really* think that something needs to be done about the stock buoyancy system... Regards, Northstar

Merry Christmas! (depending on your time-zone) I'll have to dig out some daytime photos soon. Considering most of my rocket launches are night-launches, though, I might have to take some new ones from my current save, which uses 64K Real Solar System... RSS causes some *occasional* bugs with anything left on the launchpad when you exit phyiscs-range if your terrain detail isn't turned up, by the way. I suggest turning Terrain Detail to the highest setting you can tolerate CPU/RAM-wise to avoid this, as losing a Mass Driver stack to a physics bug could get QUITE annoying and expensive. I also suggest installing Kerbal Joint Reinforcement, as it helps a bit with buffering the game's physics against some of the random motions upon loading that can simply decimate a 70-unit Mass Driver stack... Merry Christmas and a Happy New Year everyone! -Northstar-

Actually, Eve landers become EASIER with realistic aerodynamics, as realistic drag-modeling DRASTICALLY reduces the Delta-V to orbit... Due to Eve's high gravity and scale height, vehicles that reach high-supersonic/hypersonic speeds in-atmosphere (such as spaceplanes) also become much more profitable with realistic aerodynamics, as drag falls off *sharply* after breaking the sound barrier... Merry Christmas and a Happy New Year! -Northstar-

There is a third option you didn't consider. One that's vastly superior, and I'm sure you can see the wisdom of... Nerf the ISP's (possibly replace them with real world ISP's and fuel-densities, as all real fuels are either lower-ISP or lower-density than stock KSP). This way it requires the same sized rocket to get to orbit as before, and makes the game slightly more realistic/challenging once you get to other planets or moons... See the related discussion thread: http://forum.kerbalspaceprogram.com/threads/104061-Should-Specific-Impulse-%28ISP%29-be-nerfed-with-improved-aerodynamics Merry Christmas and a Happy New Year! - Northstar-

Merry Christmas to you too! I actually just really hope they bring in Ferram. He's the only modder who seems to have a sufficient knowledge of how to model aerodynamics in KSP that he's created not one, but TWO working systems (FAR and NEAR). I think they can work with him to iron out the wrinkles of which particular features to include and not to include, and perhaps even collaborate to find ways to IMPROVE his code so it uses less memory, etc. And, for the record, I would also like to see a lot of the data screens like in FAR (should require opening "Advanced Mode" in the VAB/SPH like with the parts catalog)- I find KSP just doesn't provide enough informational displays in the stock game in general. As long as the displays don't show up by default, and have to be "enabled" by clicking a button or setting an option, it shouldn't be too overwhelming for new players... Regards, Northstar P.S. The informational displays in FAR aren't technically NECESSARY to build a plane/rocket- they just give you data about the expected performance of your vehicle, so you can make changes to it BEFORE you set it out on the Launchpad/Runway... Merry Christmas and a Happy New Year to everyone! -Northstar-