KerikBalm

1) Aerodynamics model: both the mass dependand drag, and that drag scales with the square of velocity, whereas lift is linear 2) ISP: thrust should vary, not fuel consumption. Relatively minor: ISP curves should be adjusted so that ISP drops even further in atmospheres over 1 atm (jool, eve) 3) Gravity/mass effects: Patched conics don't support lagrange points and such, effects of gravity are applied to the whole craft's Cg, rather than at each part, which has some minor effects as far as differential forces on long craft. (minor enough IMO, given that the simulation has limited resources).

The fuel consumption appears higher because of the wya KSP handles ISP, and the very poor atmospheric ISP of the LV-N. Its ISP is only 220 at 1 atmosphere, and the game lists the fuel consumption needed to generate 60 kN of thrust at 220 ISP. Use it in space, and you get 800 ISP, and your fuel consumption to generate 60 kN of thrust is much much lower. However, it weight 2.25 tons, while a LV-909 for reference weighs half a ton. So for the same weight, you could send up a LV-909 and 1.75 tons of full fuel tanks. Thus for small dV needs, the LV-N is not so attractive - but for craft that you will repeatedly re-use (by refueling), or craft with large payloads and fuel tanks (that can get away with poor acceleration), the LV-N will "catch up" and surpass all other engines (except ions)

I remember when the Ion buff came out, ion SSTO planes were tested for their ability to make it to LKO, and IIRC - they can, just barely, but unintentional infiniglide effects are also at work. They are mentioned when discussing Eve SSTOs (as the only thing not easily disproven with simple math), and IIRC, ion planes have been used as a first stage for the lightest eve ascent vehicles yet made (somewhere on the order of 15 tons). Laythe - well I haven't heard much, I presume its possible if Kerbin is borderline - the oxygenated atmosphere makes such a design fairly pointless though (combined with the 15x too high jet engine effective ISP) But Duna... I haven't heard any talk of duna ion SSTOs. I want to make my next reusable duna lander a plane, as so far they've all been rockets - but designing a workable plane for duna is hard enough using rocket engines I don't know what to do with ion engines. So far my Duna plane designs are nuke powered, but I still feel like there's no point in adding wings, as I could make a better conventional parachute landing, vertical launch LV-N powered rocket But Ions... they would only work with wings, their TWR is 3x that on Kerbin, so it should be relatively easy to construct, no? Can anyone give me tips for Ion powred planes on Duna? Ideally ones that can carry 2 kerbonauts in lander cans

I'm not sure this is ever a good idea, and if so, it is only in really limited circumstances. The problem with this highly eccentric rendevous (aside for the more challenging rendevous), is that you shift the dV requirements from the mothership to the lander Lets assume your "highly eccentric" orbit is going right to the edge of the SOI. In this case your lander will need enough dV to basically acheive orbit + escape velocity... which laregly negates the point in doing a rendevous in the first place (if you're only doing a single destination, and its near kerbin, such as duna). Such an eccentric orbit means the lander needs more dV capability, which means it must be bigger. I suppose if the orbiting "mothership" is much more massive (suppose it has habitats, life support for very long durations, etc), then it makes sense (similar to an aldrin cycler almost). With multiple destinations in mind, the mothership will have a lot of mass for fuel, and you probably have a lander intended for multiple moons, with large excesses for some. However, it is almost always a good idea if you add a 2nd rendevous*: Your mothership arrives in a highly eccentric orbit, and detaches a lander and a fuel depot (fuel tank+ docking ports). The lander engine places the fuel tank in low orbit around the moon, and then descends to the surface, then ascends, and rendevous with the fuel tank. The fuel tank then supplies enough dV to make the rendevous with the mothership that is in the highly eccentric orbit. No sense in carrying the fuel that you need to get that eccentricity down to the surface just to lift it up again. Of course, there is also no sense in slowing all your fuel down into a circular orbit, just to accelerate it again. You can save a lot of mass by avoiding situations where you decelerate something, only to accelerate it again *excluding cases where the savings are small, and the dV used to dock is likely to surpass the savings.

For the sake of our CPUs, the large engines should be on equal footing with the small, ones, lest we balloon our part count. The new NASA parts have multiple nozzles, but only count as one part, which is good if you want clusters for visual purposes. The issue with the poodle is that it is simply too heavy, or too low thrust (take your pick), its TWR is abysmal. I think it has sufficient thrust for its obvious uses, so I'd just make it lighter. Only the nuke and the ions have a lower TWR. Even the LV-909 is too weak, in almost every case, substituting a 48-7s is better. The skipper on the other hand: I'd make it like a big LVT-30/45, give it 370 vacuum isp I've modified the stats on my game such that the skipper gets 370 ISP, the poodle is half a ton lighter, and I swapped the ISP values for the mainsail and the 48-7s -> I think its much more balanced that way

I typically use ions for this, when they buffed ions, my control became less precise Of course, even the simplest ion system weighs more than the simplest RCS system, and can often be hard to set up as far as placement of the ion thruster. I only use them on my re-usable interplanetary tugs that have high payload fractions. Basically, after I reach a limit with playing with the nodes, I point my ship in a direction I think I should go, light the ions, see if it gets better or worse, keep doing that until it starts to get worse/I hit my desired orbit. Ion ISP allows for trial and error, and the low thrust is good for very precise maneuvers. My tugs also have significant dV reserves in the form of Xenon gas, for when they need to deliver a large payload, and don't have enough liquid fuel to make it all the way back to LKO (which is where the buffed ions really save time)

I would call them male humans. Think about it: we must find a "host" (female) to inject genetic material into in order to reproduce. Injction with that genetic material causes parasitism of the host whereby host nutrients are used to replicate another male (50% of the time). Yep, males are viruses, or rather, sperm are viruses, and males are carriers of the virus, and females are the host in which it replicates... or something like that. Change "handshake" to "sexual intercourse", and you've got what you want. Also, while a significant portion of our genome does contain integrated viruses, I hope you guys are not including transposons or retrotransposons, because then you're oversimplifying the continuum of what a virus is - its not so clear sometimes (particularly when it comes to degenerate cells like mycoplasma, and simple nucleic acid molecules like retrotransposons or viroids).

At depends if we get working fusion reactors or not. If not, we're not going anywhere, we'll be too busy fighting amongst ourselves (we might still do that with fusion, but we'll go places to fight )

This question makes about as much sense as a questions about making a Franchise business model - Hindenburg airship hybrid. If your question about hybridization is simply limited to combining any part of a human's DNA with any part of a Virus's DNA, then I've done it with Adenovirus and human promoters. No, there were no signs that the virus was sentient. Or are you talking about males in general?

It is possible, but very difficult. You could use a virus/virus like vector. You could extract adult stem cells, modify them, re-inject said modified stem cells, that over time replace all the cells in the grown organism (since almost all cells are replaced fairly frequently).

"Contributes to reactive movement" is just non specific BS. It is correct, but it does not explain where the forces are acting, only what the effect of those forces are (conservation of momentum) There is a force that accelerated that gas, there was an equal and opposite force on the rocket/spacecraft. If you had an electromagnetic coil gun, the magnets would be pushing off of the projectile, and vice versa. In the case of a chemical rocket, there is physical contact. Its just the same as an orion drive: sure, the nuke going off sends a lot of stuff backward, but its the stuff going forward hitting the pusher plate that pushes the rocket forward. In the case of a liquid fuel engine, where the fuel ignites at the very narrow base of the nozzle/in a combustion chamber, the gas pushes off of itself (just a bunch of balls bumping into each other) The stuff going backwards initially leaves the rocket without directly exerting any force, while the stuff going forward hits the rocket nozzle/wall of the combustion chamber, and pushes the craft forward. I will conceed that I should have specified that the gase pushes against the walls of the combustion chamber in addition to the nozzle, and the combustion chamber can be quite large and distinct from the nozzle in a solif fuel rocket like so: Where the expanding gas is produced far outside the nozzle, the force is not just applied to the nozzle, but also to the interior wall of the "top" or "front" of the rocket. I should have specified the nozzle+combustion chamber, which in the case of a solid fuel rocket is quite large. In the picture above, you have a high pressure gas in a tube basically. If that tube is sealed in all directions, its exerting a force against all the walls of the tube. The forces are equal and cancel out, no net force. When you put a hole in one of those walls, you have a force on one side, but none on the other as the gas freely escapes, and a net force is produced. You can easily ignore this and just use equations like M1V1 = M2V2 (numbers should be subscript). But that is skipping over where the force is actually being exerted, and just showing the net effect of that force. Chemical Rockets are pushed by the pressure of the gas - period The net effect is of course that the gas is reaction mass.

You don't seem to understand that you are talking about the same thing. Its like saying "some of the effect is due to X, but a great deal of the effect is due to X" All the force comes from the expanding gas pushing against the rocket nozzle. It is the rocket nozzle that shapes the exhaust and allows you to throw stuff in one direction, instead of omni-directionally (which would produce no thrust). Again missing the point. As I explicitely said "A gas will always expand" I was referring to if it was possible to have a gas be denser than water, without turning it into a plasma. Yes, some would freeze, but assuming the case of a glass of water at room temperature, the vast majority would boil off in seconds (if not shorter), and you'd have very little cooling and ice, I doubt you'd even get a core of ice, but rather some ice "dust" And as far as "radiative transmission... low enough or absent" - I already addressed that "ignoring sublimation from solar heating when it is in the sunlight" - obviously that means if there is sufficient sunlight (ok, it could be another source of radiation, other than the sub), it will sublime, if not, no sublimation.

The coconut has inertia, and will resist if you push against it, you can thus push against it, accelerating it (and yourself) in the process Not really. The rocket has a nozzle, the fuel/propellant has mass, and inertia, and a lot of energy, as it expands, it pushes against the walls of the nozzle, pushing the rocket forward. At very high pressure, ie right at the moment of combustion for a standard chemical rocket, the gas is pushing against itself, yes, but certainly not the exhaust emitted half a second earlier (which will be hundreds if not thousands of meters away by that point). A rocket would produce thrust even with instantaneous pulses, not by continuously pushing against its earlier exhaust. You could even have soldi fuel pellets/ explosives like a firecracker. Set of a firecracker in a cone in space, it will push the cone forward when it goes off. A rocket works the same way, just continuously. The exhaust pushes against the nozzle. Nope, as the gas dispeses in all directions, some contacts the nozzle, and pushes against the nozzle, longer nozzles = better in a vacuum In all directions, according to the speed of the molecules within it. Null. Nothing, no power. Having something at 1 ATM surrounded by a vacuum is exactly the same as having somethin at 2 ATM surrounded by a gas at 1 ATM. All that matters is the pressure differential. Its not "how powerful is the vacuum?", its "how powerful is your pressurized gas?" A glass of water would not freeze, it would boil without the pressure to compress it into a liquid state. If you let it cool down enough to freeze first, then it may remain as ice (ignoring sublimation from solar heating when it is in the sunlight). People speak of space as cold, a perfect vacuum is neither cold nor hot, its nothing. You will cool down due to black body radiation, but that takes time, its certainly not like dropping something in liquid nitrogen - and thats ignoring the sunlight of course (so it will get very cold on the night side of the moon, and very hot on the day side, but its not space per say that is cold, it is space that allows it to heat up or cool down as there is no other matter for it to transfer heat to/from it) I'd have to check, but i'm pretty sure its possible. I know its possible if you include plasmas, but non ionized gas... I need to check. A gas will always expand, by definition, its got nothing to do with density, at least not until you get to a mass similar to the gas giants where its own gravity is sufficient to contain it (in this case its a combination of a density *and* total mass). The only way you'd get a gas to be denser than water is by putting it under intense pressure (and cooling it down to just above its freezing point, so you'd want something with weak interaction forces to have the lowest freezing point), and that pressure means.. a pressure differential, as I mentioned above... it would produce a very powerful expansion if placed in a vacuum (or even a pressure of 1 atmosphere)

That does sound logical, but thats not the way the English-Scientific language has evolved. Now the meaning of organic basically means carbon containing. There are many "organic" compounds that were never made in a biological organism. Likewise, there are some compounds produced by organisms that are not considered "organic" http://en.wikipedia.org/wiki/Organic_compound http://en.wikipedia.org/wiki/Organic_chemistry I think it would be best to ask if it is possible to have non-cellular life. Ie, life that does not consist of solvents enclosed in membranes, wherein the metabolic activity takes place on or inside the membrane

I'd say its definitely possible if we're willing to modify our genomes

You want the highest frequency/ lowest wavelength that you can focus (X rays with grazing incidence mirrors basically), this reduces beam dispersal. Approaching hard X ray wavelengths.... if you had say... a 20 meter diameter focusing array (or a phased array of about 20 meters), and a laser output of a few hundred terawatts (we've made peta watt lasers already), then you could still explosively vaporize targets dozens of AU away with a pulse of only about 2 gigajoules. I did all these calculations before using an online calculator. Ranges of nearly 1 light hour are feasible. You don't want a continuous beam, you want a pulse that will vaporize the target, ie the target's surface will literally explode. Abalative material and spinning like mentioned above would work well against a continous low intensity beam... but a few gigajoules of laser energy delivered onto a small area in a thousandth of a second... the surface detonates, explodes, sends a shockwave through the vessel that will not react kindly with its occupants. In practice, it is easier to make lasers with longer wavelengths more efficient. So you'll have less energy wasted going into heat when firing them (at close ranges, at long ranges, there is much wasted due to the beam diverging), and heat buildup would be a major concern for a spacecraft firing gigajoule level laser pulses...

An extra 1,000 dv lets you get most of the way to orbit, then about and land again, and then go back to orbit... sure its a nice capability, but its also going to mean I'll need to arrange for a lot more fuel shipments for my lander to visit the various places I want to go (I don't use hyper edit). I think I'll just set my design dV to be an even 1,500 m/s, not including the RCS fuel for docking

Hmm, I hadn't realized the rotation of Duna was so slow... 31 m/s is nothing.... -Just checked, it takes 3x longer to rotate than kerbin does... combined with a smaller radius = meh... about as irrelevant as landing on the Mun IIRC drogues pop at 10k on Duna, and the mains pop at 9k. That should mean that any landing site under 8km should be accessible without using much dV to cushion the landing. I know that Eve's problem is mainly the atmosphere, but the high gravity also matters... For duna, I suppose I'll just use m*g*h = 1/2 M * v^2 -> g*h = v^2 g= 3 m/s (roughly), so a difference of 5km in landing site should be a difference of 2*3*5,000 = v^2 -> v^2 = 30,000 v= 173 m/s So a rough estimate is 170 m/s less dV needed to ascend from a 5km higher starting location. I guess I could have calculated the surface velocity too using the wiki... (I didn't feel like throwing together a mission in a new snadbox, and going there to observe it). I guess I'll just set the design goal for 1,400 m/s to have a nice error margin, then decide about the crew and composition of the rest of the lander(s) - I used to always try and put enough chutes on for an unpowered touchdown, but now I'm seeing that they are easily costing me more fuel/dV on the ascent than a quick thrust before touchdown would cost - although thats not a problem on non-reusable landers where I can jetison the chutes along with the first empty tanks on ascent. More tricky will be seeing if I can save any fuel using modded electric fans on an duna plane... they're dead weight, and don't get it going very fast, nor can it fy very high in that atmosphere... I'm not sure how much my Kerbin testing will translate to duna (sure, I can correlate an air pressure on Kerbin to an altitude at duna... but Duna's got less gravity, so I could fly at a lower AoA, and thus a higher speed).

Yea, check my edit. By using the value for ISP in seconds (800), rather than exhaust velocity (roughly 8000), I got a figure about 10x too low - 8,000 m/s is about the upper limit, not 800. I guess I can ask another question... how much dV do you need to get into a polar orbit? How much does dV vary between the lowest point and the highest point (I hear people talk about this often for Eve, where the difference is very large... but I'm curious about Duna)

Yes, I'm aware of all that.... I've seen those engine charts before, and I'm making my own graphs (so that I can see how much dV adding x mass in parachutes costs my lander, so I can optimize how many chutes to use, since using engines to brake also costs dV). The "problem" with those charts, is they show mass optimal, not fuel optimal. If I have a 48-7s, weighing .1 tons, vs a LV-N, weighing 2.25 tons, for the same mass craft, I get to carry 2.15 tons of extra fuel&tanks if I use the 48-72. There is a certain desin dV, where both a 48-7s and a LV-N powered craft would weigh the same to acheive that dV. Below that dV requirement, the 48-7S is mass optimal, above that, the LV-N is mass optimal. However - at that dV, the 48-7s is burning 2.15 more tons of fuel than the LV-N. Go slightly below that dV, and the 48-7s craft can weigh less but it will still burn more fuel than the LV-N because it can start with 2.15 tons more fuel. When looking at the mass optimal charts, its fine if I don't want to re-use a vessel. I want to look at fuel optimal, the craft that can get me to and from the surface of duna using the least fuel per trip. This is not neccessarily the lightest craft that can make the trip. My graphs can show me which lander uses more fuel to acheive a given dV. I just need to know.... do I really need 1380 m/s to get to orbit from Duna, or if I make all my landings equatorial, can I use a craft capable of less dV (thus less fuel use, thus less resupply missions to the Duna orbital fuel depot)

Correct, I would model it as the only rocket engine in the game where ISP decreases as it approaches a vacuum. It would have a very high ISP (greater than the nuclear engine) in the atmosphere, and a much better TWR than the nuke engine. In a vacuum.... lets say 370 ISP? something like that. I would incorporate the intakes into the 3d model, and have it not use any other intake parts. The only thing is... it might make the aerospike engine even less desirable - so to compensate for game/balance reasons, the Aerospike should have a better TWR. Although... it would be really nice if thrust scaled with atmospheric pressure, rather than fuel consumption, to match the ISP curve. It would also need a bit of a velocity curve, since it is very similar to a ramjet, it won't get much air augmentation at very low speed (ie, at T=2s after liftofff, for example) In that case, I'd have the air augmented rocket have superior TWR to the Aerospike in the atmosphere and close to the "soupy" terminal velocity. So we could imagine an Aerospike booster to get velocity up*, then the air augmented rocket fires for most of the rest of the ascent and gravity turn. It works in a vacuum, but due to its weight, you wouldn't want to take it beyond LKO unless your destination has an atmosphere. *I wonder if you could combine the desing with an aerospike design, ie the core rocket is an aerospike, and then once you get to speed, you get significant air augmentation of thrust....

Ok... FAR is proving to be a challenge... but I really can't tell what is going on. I can make small basic jet SSTOs, and small turbot jet SSTOs. Then I try to make a large payload carrying SSTO, and for some reason between mach 1.2 to 1.4, it just pitches up, no matter how close to 0 I try to keep the AoA, no matter mow much fuel I shift forward. I tried a complete wing redesign (from a forward and aft wing design, with the engines on the forward wing so that it would balance when tanks were empy) to make a large delta wing.... Still, No luck violent pitch up at mach 1.4 What gives?

So I was playing around with the rocket equations and a graphing program, so I could optimise eninges for various purposes (mainly least fuel used for a given lander + engine, for designing reusable landers that dock with orbiting fuel depots). And I realized, according to the rocket equations, the Aerospike engine can't get much more than 800 m/s of dV (assuming a lander can, engine, and tanks... legs and chutes drops it even more for practical fuel amounts) without shedding fuel tanks. I know I've made duna landers before using just aerospikes.... but the dV map shows that I need 1380 m/s to get to orbit. Given the thin atmosphere and relatively low gravity, I doubt there is such a difference if one lands at 0 meters or 4,000 meters elevation. I'm also guessing that this figure doesn't take into account the planet's rotation... ie 1380 is what you need at the poles, but not the equator? What is a realistic dV design goal for an equatorial duna lander? Using the 1380 figure, it seems that nukes are the only way to a duna SSTO, but I know that is not the case (although at any rate, it seems I'll be using LV-Ns for minimum fuel use per mission, unless the real dV needed is really low) *edit* oops, was using ISP rather than exhaust velocity (it, off by a factor of 9.8) *edit* The question still remains though

Yes, I know, water based life may not be the only type... http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry but, they all have some problems that may or may not be insurmountable. H20 is pretty common throughout the universe. Maybe we are looking too narrowly, maybe we're not. If we're not, we may have a solution to the Fermi paradox. If these other biochemistries were viable, we'd expect there to be a whole lot more life out there. We have no evidence to support these other biochemistries being viable. I can't prove they aren't viable, but I also can't prove that there isn't a teapot orbiting pluto. I'm not saying other life isn't out there, but I am saying its likely it rarely makes it to our level of technology/spaceflight, and probably (within our galaxy) has not mastered fusion power (or even more advanced... bussard ramjets and antimatter production/storage) Yep, I think we're on the same page here. As I said, life on Earth is already 80% of the way through the usable lifespan of our star. If we blow it, there probably won't be time for another civilization to arise. And we sure look like we've got a good chance to blow it. Of course, if there were billions of planets with life out there in our galaxy, and they all blow it at about our stage... then it seems likely that we are doomed too. I hope the 99.99% filter isn't occuring at about our level, but rather its spread out across multiple stages (such that there aren't billions and billions of earthlike planets), and the mere fact that we're multicellular animals means that we are past most of the filters, and that we are sentient means we are on the cusp of being past all the filters and to interplanetary(or whatever you call colonizng moons and asteroids) colonization and eventually interstellar travel Well, the biofilms should be very widespread. Microbial matts once covered almost all of earth's seafloor, even with much more active weather and geologic processes, much of it has survived. Other evicence, like banded iron formations, is very abundant. The evidence should be all over the place on mars without an active hydrological cycle, or subduction and active geological processes... There are inverted relief formations... which basically form when old riverbeds are more resistant to wind erosion that the stuff surrounding the riverbead. One explanation is simply cementing due to water... but I wonder if inverted relief formations on mars are really massive biofilm fossiles from old riverbeads choked with microbial mats... But on the other hand... we have sent rovers into the old seafloor, to places that had standing water... no rocks displaying banded iron formations (so no oxygenic photosynthesis evolved?), no fossil biofilms mats.... I'm pretty sceptical

These require no liscence at all in the US