PB666

First off, let me just say that from a couple year ago when I first started building parts this group has come a l o n g w a y in terms of improvements. What I have done: We need however some just basic glossary of terms somewhere, and the term defined like raycasttransformed = (this is what it does, this is how to employ it). . . . . . alphabetized and stickied. It would be nice to see an index at the begin than a headed paragraph on each keyword. The KSP specific area that hung me up were these terms and thrustVectorTransformName, animationName, and raycastTransformName. Built a new, from scratch, ION drive complete with emmissive - would absolutely not have been possible without the tutorials. Built a new, from scratch, Solar panel (10 meters by 100 meters, no joke), extendable non tracking (on purpose) solar panel. - animation would not have been possible without tutorials and searches here Built from scratch a new set of lattice elements (including 5 meter long aluminun poles, corners, T, 30 angles, pole anchors. So here is the basic issue. Im trying to control the power input for my ion drive. So basically this is it, I want to burn 70 units of electricity a second (For my panels im equating a unit to a kilowatt, the ion drive needs to burn 70 units per 0.001 thrust the xenon gas used then needs to be used accordingly to the ISP which is 9000. How to do? Im not exactly sure how electric charge is managed in an ion engine.

You are talking about physics way beyond scope here, lets bring it closer to earth With chemical energy we want to improve ISP because the reaction masses momemtum is derived from energy bond breaking and formation and if it is not utilized for generating thrust it is wasted therefore we don't really care that our E to p ratio is great, the limit to this is internally controlled. The reaction has a certain amount of mass and that mass has a certain about of O-O, C-H, C-N, etc bond energies that can generate N-O, C-O and O-H bonds of lower energy. Once you have converted all that reaction energy to craft and gas energy your ISP cannot go any higher. Not the case with an ION drive, in the ION drive xenon has no bond energy to be derived from lower energy states and we are adding energy to strip electrons from the outer orbital. Consequently we can continually add as much energy as we want, 9000 ISP seems to be great, but then where does that energy come from, and then if we compare the kW of power generated in a unit space by chemical versus kW of power in unit space by solar or fission reactors on board space craft, then thats were the rate limitation creeps in. If we begin our mission at venus and travel to mercury the problem is much less severe (except for the low efficiency of solar cells and high radiation levels essentially fry them if they are not turned at an angle), but our mission begins at 1.1 kw/M (1.361 actually but measures the entire spectrum) and goes to 0.432 the earth value. If above earth we get 0.3 kw/M on mars we get 0.12 kw/M. The weight of xenon that you have on earth will not help you on mars, because you will need 2.5 the mass of solar panels to drive what ever ISP you decide on (as long as the power loss is minimal). Again I repeat the point, the problem is not mass, though if you have the luxury of having reaction mass to dispose of it helps. the problem is power, energy, juice, hv, amps*volts whatever you want to call it. He's arguing in the other thread that a post LEO mars mission needs 19,000 dV, ok so if your craft begins to saturate dV with a certain mass of Xenon and you are kicking out just double the E/m ratio, you are going to pour through that mass in a hurry but for no good reason, because the excess momentum per energy you obtain (with more ion drives and its associated mass) has to push more Xenon mass around. You don't win. The only win scenario that I see is to make use of static orbits like Earth L2 and Mars L1 to park gas and pick up, therefore not carrying the weight. A better Idea might be to park permanent bulky solar carraiges in space, made of less efficiency light weight panels that have masses of 0.1 or 0.05 kg per meter squared that a ship can dock into once in 'safe space' such as at L2 or L1 of mars. and then use that energy carriage to carry it back and forth. another 300 dV due to the non-perigee burn losses.

You are looking at the problem at the wrong perspective. To be certain there are microbes with an effectively zero mutation rate (at least at standard temperature and pressure, although they tend to live at higher temperature). Start by going backwards in time to about 700 to 800 million years ago, so you have a period prior to the cambrian explosion where the earth goes through some rather dramatic environmental swings. It goes from hot greenhouse state to a cold state caused by the great oxygenation event. Simple fission for bugs works well, and we do see perfectly replicating creatures, cloning oneself is effectively immortality from a microbes point of view, up until something massive changes, then its what we call an evolutionary dead end. Eucaryotes get around this issue by exchanging gametes, simple enough we could have an exact copy of mother and father inside our genome, but theres a problem because the genes sort dependently on linkage groups. To solve this problem eucaryotes more or less have a recombination facility known as meiotic division (and its presteps). This cause the genes on linkage groups to sort semi-independently, but consequently to be realized it must also create a new, different, individual something that cannot be a clone. Having two copies now allows for a higher mutation rate, the mess gets sorted out by the F1 generation (selection). It does not have to be like this but it tends to be that case that parent one creates a meiotic cell and parent 2 the same, and they combine these into filial X (with two chromosomes of every type with no single chromosome exactly like either chromosome of the parents). IOW parent cannot carry on by cloning themselves by fission. This is a wildly successful group survival scheme for complex organisms. So now you have progeny that are different and in selection with the parents, in a zero sum game, if parents cannot procreate at the rate of F1 then they are now consuming progeny resources, so selection does not favor immortality, instead it favors variation. There are other mechanisms, like balancing selection and heterozygous selection rates that favor diversity this allows populations to be older by showing more diversity than actually exists (offspring tend to select non-alike mates for certain critical traits like immunity). This has the benefit of allowing them to live longer and produce less progeny.

Thanks for responding, I forgot to tabulate this So basically the current particle acceleration drive is 70 Kw/N (This number comes from NASA 35 kW/500 milli newton) cannae drive is ~30 Mw/N (30000Kw/N) photon drive is 300 Mw/N The problem is immediately evident: A meter of sunlight is 1.1 kw however at a 25% efficiency it pans out to about 0.3 kw per meter. To get one newton of power then you need 70/.3 = 233 sqm/Newton, This is the best. If we look at the Cannae drive its advantage, even for clearing space junk becomes evident 30,000/0.3 = 100,000 meters of solar per N. If we go by mass then this is 100000 kg, and that results in an acceleration of 10 uN or 1 ug of force. the photon drive is then 1 uN and its relative force is 0.1 ug. To make this more clear, we could improve the efficiency of the ION drive by a few percentage (14% maximum and the efficency of the solar panels 200% maximum and you still have no less than sqM/N. I have to remined everyone that the tiniest chemical thrusters are in kN of thrust, we are talking about 75 sq.meters of area to provide 1000th of that. You could lower the weight of the solar panels to 10 meters per kilogram, but you still have 1w per meter max to deal with, you still have to spread panels over wider space, not a problem if you have a very heavy load, but if the intent is to accelerate or you are using them in close orbits, you will have a stability problem that needs to undergo reinforcement problem. I solve this in the game by crafting new poles and joints, but there are practical limits. A stabilize wire structure has a problem with solar panels in that panels need space to track the sun. This is the limit I am refering to, for ION drives the efficiency limit basically sets the downstream limits (how many Kw needed, theoretically nuclear is limited by the heat exchange problem, unless there is a cheap way of direct charging; solar is limited by solar irradiation per unit meter of space and the technical mass requirements of reaching and filling that space) so this is the limit, the practical limit, it is the Mars problem. How do you get a fully fueled land and return vehicle to mars. What you came up with is an impractical limit, because it does not take into account the technological limitations. We cannot increase much the efficiency of ION drives, there is only so many Kw to begin in any unit area of space at any radius from the sun. We can lower the weight required, but that can only be done to a practical limit. For example suppose you use silicon Fresnel lenses to refract light, there is a limit on how thin the material can be (basically determined by the wavelength of green light) before you start causing it to do something else, like diffract. I will summarize at the end. In terms of manipulating the vacuum of space, again cannae might interplay in some unknown way, but currently we do nothing extraordinary to achieve this, but if we knew more about the field it might be possible to manipulate them to our advantage, I don't see it but the possibility exists. My point is this, it hardly matters, for deep space flight the problem is not momentum per say, its energy, and the cannae drive is not immune, if anything its magnitudes more vulnerable than ion drive. Priority should be finding better power sources for the ION drive, The cannae drive cannot compete with current ION drives, the reason is this: 1. The small amount of thrust it produces 2. The weight of the drive 3. The weight of the solar panels required to power the drive. 4. The force of drag acting in LEO 5. The fact that even junk would be difficult to catch with such low acceleration, or to state more precisely you could catch objects in geostationary orbit, but everything else is subject to variable forces So we can currently ignore both the Cannae and Photon drives. Our example is this, lets say we accelerate a kilogram of xenon and accelerate it to a 1 and the ship weighs 10000 kilogram m1v1 = m2v2 1/10000 = v2 ∂E1 = 1/2 ∂E2 = trivial 2 ∂E1 = 2 ∂E2 = trivial 4 ∂E1 = 8 ∂E2 = trivial 8 ∂E1 = 32 ∂E2 = trivial 16 ∂E1 = 128 ∂E2 = trivial Higher ISP result from higher momentum ejecta but at a much larger expense of energy required to generate it. The energy sources used to accelerate the mass are not even adequate for current transfer requirements from earth to mars for manned space craft, more ISP is not the problem, the problem is critically the supply of energy. This HiPep that they created is 31 x 46 cm, it requires 35 Kw, thats 245 times the solar radiance for that and produces 0.5N. ug here means 10E-6 earth surface gravities. Again we have here the practical limitations, so the equation is this. I will set a current of 50 ug of acceleration for a people carrying space craft, this is not practical for many space applications. The mass and the area of the ION drive is immaterial, find ways of increasing energy production of the spacecraft without raising the weight, it can include better construction materials, lighter solar panels, more efficient solar panels. I am not contradicting what you are saying, but when you say "Which tells you that to propel yourself efficiently, you want reaction mass with high E at low p." means that you energy production is not rate limiting, I completely agree that you want to limit p derived from m, BUT this means that you have available a relevant energy source to create a level of E that will achieve a desired dV/t My example here is that I have a craft with 38 2x6 meter solar panels (to be realistic I need 40 more) and 4N of ion drive and a _modest_ 1 human carrying 12000 kg space craft, it has F = 0.3333 mN at 9000S you can sit down and calculate how long it will take to realize the 30,000 dV available, then you understand the limit that you should be thinking about.

40 kv, lol. The 29,000 base dV he gives is not the most efficient. he is basically establishing a minimal escape (he doesn't care about time) orbit after which he establishes a mars transfer orbit. Its better to get all your transfer velocity at minimal earth perigee. In fact the horizons space craft did its escape burn before achieve a stable earth orbit. This is because most craft kill engines to mount the apogee before circularizing, but if the apogee trajectory is in line with the desired escape orbit you do not have to waste as much gravity versus time (hoovering, very minute at this point in the flight) losses simply burn an escape vector along the prograde. Why are we seriously discussing these high g-force accel and decel from orbit, we don' have the energy, we have nothing even close to the energy. To stack rockets you have to essentially add 4 times the mass in each subsequent stage, so you could not simply stack rockets, you would have to create a pyramid structure. The argument here is not simply getting to Mars, we've done that. In the 3 year period you have to keep humans alive and return them, you have a mass, the longer the journey the more that mass increases. Lets get a little dose of reality, the voyagers are moving at something like 20km/s alot of the v came from oberth effects and body hopping across the solar system. They are light weight spacecraft. We are talking here about manned space station like objects so the mass is a to two magnitude higher, and then talking about direct dV a couple of times what these craft had. This is something like 20 to 100 times more N*t than any craft that we have managed to produce.

I gave up the notion that information could not be transferred a couple of years ago. I don't even think FTL is a limitation for entanglement since for quantum states speed and time have much less meaning.

We have been having a running discussion in this subforum for the last year or more concerning a type of energy that does not require an apparent mass to generate momentum. Although energy can be converted into light which has momentum it has very little momentum given the energy contained within, and so finding something that has a magnitude more momentum per input energy created alot of discussion. In the end here I hope to show that it really matters little. To start off this analysis lets imagine the settlers of the mid 19th century American west. To accomplish their journey they had wagons with supplies and draft animals to pull the supply, this carried them across an expanse that was devoid of trade goods to either feed themselves or their livestock. Along the way the live stock feed, and because high energy foods spoiled they would kill animals and butcher them for meat and fat. There was a thing called winter, at which point unless you had settled in, it would not be a good thing to be in space. Conceptually speaking all major exploratory journeys are like this, if we imagine the discovery ships, they had to have supplies to last them several weeks, they might stop at islands to pick up water and supplies, and they would not want to be caught in a hurricane. Therefore the concept of expanse, resource management and risk have been dealt with. So now lets consider the trip to or any planet. Our Mississippi river is the LOE, we first have to get our ship up across the problem of drag and its desire to fight orbits. During this phase of the journey we cannot rely on any space resource and so it is a given that the initial state provides the energy and mass to create momentum. Once we have a semi-stable orbit we then can examine the problem of space. Space is a name, it has a sort of implicit meaning that it has no stuff in it. Actually space has alot of stuff, at least our local space, relative to the vast expanses of emptiness between galaxies. The stuff in space however tends to get concentrated into inertially defined bodies. Between these bodies are gases and for a traveler these gases are always in motion and because the gases are almost always charged (that means gas is a mixture of plasma and gas), the gas is maintained in a rarefied state by momentum and electromagnetic energy from the sun, as a consequence it can at times be non-inertial. To be clear here, the density of gas, even in the atmosphere of the sun, is so dilute it is of little practical use. That is to say in the time frame of our journey their is neither the time or a relevant volume of space to collect this an use it. The material state of vacuum space is more than an annoyance if anything, in LOE it creates drag and in interplanetary space it carries ions that can damage equipment or injure travelers. The bodies in our space fall basically into three categories. The smallest of these are asteroids and comets. Asteroids are the left overs from planetary genesis, the gas from our sun slows down and hits things out in the outer system, cools, and gases and dust that did not form large bodies eventually coalesce into dirty ice balls that get tugged by our planets and burn up, eventually. The planets clear orbits and thus are clearly inertially defined in their motion, since they are no longer colliding. Finally you have the bodies in which atomic conversion is a major character of the bodies visible appearance, at high enough energy these also emit gases. To our traveler these are the resources of space, so lets define these as such 1. Asteroids and Comets. Resources - Mass (Carbon, Oxygen, Hydrogen, Nickle, Silica, Aluminum): sub resources (metal for building, water for drinking or fuel cells, carbon for food or electronics, all for momentum), trivial amount of inertia, and transitory or impermanent destination. 2. Planets and Moons. - Inertia (as in they warp space), destinations, and the resources of #1. 3. Stars - Electromagnetism, Inertia, trivial emission of Gas and Plasma (as such also a source of electric charge) 4. Not 1 to 3 above - Quantum space - Non-zero rest energy of fields that permeate our universe (which of yet we are not fully aware or know how to exploit). So basically above we can define space as a list of virtual items, in this we can then rank them to our Space traveler. My ranking may shock but . . . A. [Quantum] space - this is the most important resource of space because it permits long distance travel and because its fields make it possible to establish travel strategies. The physical distance between destinations is in the >109 meters, traveling in drag affords speeds of 100s of meter per second, therefore matter just slows down the process. Matter also creates lots of other problems like gravitational collapses and complex body problems. B. Destinations (virtual and physical) - travelers will eventually need resources or a travel interest. C. Electromagnetic radiation - discussed below. Essentially EM is the purest source of energy, that is not to say it is the sole source of energy, but rest mass as an energy source has an investiment cost (in space this translates into mass). D. Inertially derived warping of space time - for the occasional Oberth effect. E. Mass - E = mc^2, p = m * v These are the resources what are their costs. A. Space - Not suitable for biota, no push-off mass, all* momentum must be derived within (*the status of the rf resonance cavity thruster goes undefined), energy required to reach space and return, energy taken by contamination within vacuum space. B. Destinations represent almost always a non-inertial logic, a dV required to reach them, we talk about space-time, we also have to consider dT. Destinations may have other problems like too much or too little of some other resource (Namely light). C. EM - heat dissipation with too much, energy conversion for use in propulsion and systems. D. Oberth masses - Friction or obstructions, space-time (see B). E. Mass - collection, landing, mining, conversion (not to mention cooling equipment) So basically we have a list of issues for our traveler. Breaking this down much of traveler concerns are non-inertial movements in space-time which require energy and for the most part momentum derived from mass ejection. The above is not the intent of the article, it simply breaking things down into abstractions that the next part can deal with. So what is the problem of traveling (not the traveler). If you are not going to something that cross the same space-time (in some relevant timescale) point dV needs to be applied somewhere. We derive dV Light - almost never used, but requires no mass (we have to assume at this point that the rf resonance cavity thruster is not this type of drive) Chemical - the fuel becomes the ejection mass - limited to bond breaking partial bond formation energy of the fuel. Basically at high temperature unfavorable bonds break the most stable reform as the cool. There is a finite limit on how much energy can be obtained from a chemical bond, it is defined in calories per mole and typically is in the form of O-O, H-H, N-O, N=O, C-C, C-H, C-N, C=C, C=N. Electrodynamic - the mass becomes energized by the input of energy and accelerates. (Ion, plasma, VASIMR, Hall effect, rf resonance*) Atomic - a source of heat is used to rarefy gas or liquid which then expands like chemical energy drive. We can see we need energy to produce light, we need to carry mass to produce chemical energy, we need to carry a nuclear reactor or we need to accelerate ions. Unless you want to carry all the energy with the craft there is a limitation of space, right now its solar power, (given the high mass issues with nuclear and cooling issues) Space gives effectively about 1N of thrust for every 233kg of solar panels (C). This gives a maximum 4.2 mm/s2 of acceleration (0.0004g), with that one needs about 233 meters of space. You can assume that a manned spacecraft this will be 10% of the mass so you are effectively limited to about 0.04g. I have created new ion drives and panels in the game to reflect this (HiPep design thrusters). The major problem is orbiting, this designed requires another source of accelation and is not suitable around low hv objects. Nuclear is worse, the reactors cost as much as the panels in terms of weight but much more in terms of cooling. if we argue that solar is kg per sqm then any means of reducing this improves the portability of the system. Modern age silicon lens are light weight and can focus light on a panel of much lower size and weight. This type of system works great in interplanetary flight, however only at a tangent to orbit, so inefficient transfers are not optimal unless the lens are placed on tracks that can move their positions. They also do not work well in non-inertial manuevers close to inertial bodies, this is because the incident angle shift with prograde motion. The mass of the ion drive is trivial (the most efficient drives of a few kilograms will easily consume all the energy we can currently produce), at 9000 dV the mass of the fuel becomes trivial (because you cant produce enough energy to eject it), the mass of energy production facility is just about everything. Find a way to lower the mass of energy production and Manned missions to (but not landing on) are possible.

Having rebuilt quite a few vacuum pumps its a bit of a different situation, Vacuum pumps actually create a dynamic equilibrium, which would not work well except most good lab pumps have dual stage. The vanes on a vacuum pump aren't really designed to capture all gas, just most of it, as the gas finally reaches the second stage it cant get back to the first, and once it is expelled to the second stage the gas is heated, expands floats up and effectively its not capable of reversing. The reason these pumps work like this is that rotary pumps can remove alot of gas before kicking into the second stage, and BTW is you put your hand over the outlet, it will get sprayed with oil, on most of the pumps I used for flash evaporation I had to build a muffler to trap the oil, oil may not be volatile, but when you are through putting couple litters a second it is quite atomizable. If you turn a vacuum pump off without releasing the vacuum, the oil and some gas will go back up the tube, thus the application of energy is essential to keeping the vacuum. In this space application the separation of pressure needs to be more passive, but I suspect they probably have a secondary seal and a pressure monitor with a backup evacuation system (along with pressure doors somewhere close by). Technically speaking the ISS setup does not even need to hold pressure while turning, the could simply pressurize the bearing while stationary transfer the naut and close the pressure doors on both sides, then depressurize the ring seal. That toroid needs a ballast anyway, just put a purificaiton system in there. Non-inertial or not that vessel is not an effective barrier cosmic radiation and x-rays. We had a vacuum pump that was just barely able to boil water at ambient, it got to the lyophilization limit, when I took it apart I found one vane had a rusted inelastic tensioner spring and the other vane was stuck. Not ideal of course, but just goes to show that a good position dynamic equilibrium (that is turning those vanes rapidly enough). The biggest bane to vacuum pumps is moisture or acids in the vanes, they swell up either freezing the pump or freezing the vanes in the retracted position. The way to prevent this is to every now an then dump a couple cups of vacuum pump oil down the inlet to sort of wash god-only-knows-what through the pump, then turn it off quickly, wait a while and drain the heavies from the bottom of the pan. Things like ether rapidly reduce the viscosity, on the low pressure side they can bind to the oil despite high volatility and vacuum pump is nothing if not viscous. The vacuum pump on an ultracentrafuge is a diffusion pump, it is almost completely a dynamic process, horribly inefficient but reasonably compact and suitable for circumstances were limited through put of volatile fluids is expected.

Computers can solve this problem these days. Some of the ion thrusters I have seen weight a fraction of a pound such that on a large station they can be located just about anywhere. The other thing is simply despin the station, make the correction and spin back up. BTW since thrusters don't burn oxygen, the can be set on a part of a ship that does spin, so that for off axis-DV the thruster can simply rotate to were it needs to be on that axis and fire.

The problem is the distance from the sun. If you have a serious platform in space, you can beam specific RF frequencies at mars and see what frequencies of RF are emitted on the cool down. Obviously you cannot do this every were but you could start by looking at 1, 8, 64, and so on places until you have a map. There is also a depth limit, and mars dust mucks the whole thing up.

But keep in mind that these are not used that much, on the teflon seals in the lab, they eventually wear down, so if the toroid constantly rotates the seals will begin to leak.

In the lab we use a teflon disk sandwiched between two absolutely flat glass pieces to create a vacuum, under vacuum the disk seal, but the teflon disk has a lubricating feature. It generates a considerable amount of friction. I bet the bearing has a gas recovery system that secondary to the primary seal BTW I can see they will have a problem with hunchback astronauts soon. Have you ever tried to conduct calisthenics in your attic?

You can launch your manned spacecraft slightly out of transfer window while packing somewhat more fuel, land, plant a flag on Mars, come back slightly out of transfer window, then return to Earth. It's possible to do a short fifty-day mission to Mars currently- NASA makes it the baseline for a "short duration" Mars Mission. Is it worth the effort of getting there in the first place? That's the real question.... 39 days is not just slightly out of the transfer window. So 40/200 is about 1/5 th. Lets see transfer from kerbin to the mun in 3 days, try to find the most efficient transfer that gets you to the Mun 3 kerbin hours compare that with the 850 dV it takes you to get in an efficient transfer. (Dont for get, to be really efficient your munar circularlization needs to be as close to periapsis as possible. Now lets make it fun, instead of using a 1g*mass thruster, lets use a 0.0001 g* mass thruster, 0.001g * mass thruster, 0.01g * mass thruster. I actually made a ship that did this, I cut the travel time to the mun by 80%, it used 3200 dV instead of 850, it was a tiny ship, only fuel, but in required 4 ION drives to accomplish the feat, because breaking kerbin orbit would have to be done starting way before the manuevering node. When I reached the Mun SOI, I had 16 minutes until reaching the other side and 29 minutes required to circularize, most of the fuel was actually spent slowing the craft down, it missed the periapsis circularization point by about a 2000 kilometers, required extensive negative radial burning to get a periapsis, which would not have saved any time, I would have been performing a Dawn ceres like manuever to gain orbit. To minimize the time to land I simply took out all the horizontal velocity and thrusted toward the Mun, the negative surface velocity at the suicide burn point to land. The total time took 2h 44min. Of the 7000U of fuel and 10500dV of fuel that I started with I had 38U and around 100 dV left at the end. You guys need to sit down and actually calculate out all the dV you need to accelerate, decelerate, recircularization manuevers, etc to get to Mars. When you launch using a transfer window the planet is basically chasing the space craft, if the two planet orbits are relatively close together the craft will make a nice loop around the planet and affords a very nice window to decelerate with ION drives, if you come at the SOI at 3 or 4 times that velocity your craft is going to be heading in a strait line most of which is distal from the planets gravitational energy and therefore useless for the reverse form of the oberth effect. This can be corrected in the game had I started decelerating short of the SOI, which I have done many time when heading to MoHo (ion drives are really good idea for inner most planets). And moho is an example where cutting corners actually can save alot of time, given that you have to power so much into the change of orbit, change of inclination, making the periapsis smaller than moho's orbit generally affords a fast intercept. But Mars is not Moho, the ion drives require alot of kW of power, the panels are not near as efficient, and Mars is far from the sun and Moho is very close to kerbol. A radical game for mars is not rational, a conservative game is however, provided the energy problem of the previous post are dealt with.

Err, meant to say fusion, there are no Mc2 losses without fusion, except heat released from gravitational collapse.

Right? Giant floods, enslaved apes, I disagree with Scotius (or his demonic end of the world planning cat, lol), Im having a good laugh here. Every planet had a different orbit at the beginning of our solar system, not factoring early and late bombardment phase . . . its called the N-body problem. You don't need mystical alien worlds. Also, the sun has lost at least some of its mass due to fission, and there has been an appreciable contribution of various and sundry kuiper belt objects to the orbits and mass of the outer planets.

http://robwaugh74.tumblr.com/post/138272238309/people-are-saying-the-new-planet-9-is-going-to If you are going to have a virtual planet you might as well have virtual race of earth destroying aliens on it. hmmm, mythology, theoretical astrophysics, religion . . . . . I think I may have hit a common theme here.

The HiPep Thruster produces 0.5N of thrust with a specific impulse of ~8100 ISP the kerbal dawn thruster produces 2000N of thrust at 4200. The thust to weight ratio is 8 for dawn and .1 for HiPep, with a ratio of 80:1. The Dawn thruster has a foot print of about 0.2 * 0.2 * pi meters or about .12 meters squared. The HiPep is 31 x 46 cm or about .12 meter squared. The Dawn produces its thrust/sa over 0.5/2000 or 1/4000 the surface area of HiPep. So now we have major axial crossection problems. you can fit 8 0.5 N thust per meter. Thrust density of 4N per meter. So how many meter is the standard crosssection Kerbal - FF1 = 1.2 -----> 5N Kerbal - FF2 = 4.8 -----> 20N Apollo service module (1.95d) = 12M^2 -----> 48N Orion (2.5d) = 20M^2 -----> 80N (Assume 10kg per thruster that is 160 thrusters at 1600 kg). Orion weight 10,500 kilos, this means maximum acceleration is 0.008 m/s This is not to much of a problem because you also need area to dissipate power heat production, so lets say we could some. The weight of the thruster is not to bad, but wait, were is that power coming from? Breaking it down into detail, assuming HiPep numbers . . . . 70kw power input per newton. BTW current Ion drives are 60 to 70 percent efficient, so VASMIR does not lower this, VASMIR only lowers its space required and its mass required. Solar Panels 233 kg/N 233 M2/N If you wanted 80N on your orion, you would need 18600 kg for solar panels, over about 2 hectacres of space. That 0.008 m/s now falls to about 0.003 m/s So basically solar power at its current best is useless. Nuclear Power MMRTG produce 2000 watts of heat and 110 watts of power or 0.11kw. They weight about 45kg, they take up less space than a solar panel, but 1900 watts of power needs to be dissipated somewhere. You would need 636 of these per N of thrust, at a weight of 45 each adding 28600. There are thermovoltaic systems that are more efficient, but they don't last as long, you could get that down to 10000 kg per Ion N. But that orion produces 80 so thats 800,000 kg, Those 80 would produce 2000 x 636 x 80 watts of heat 101MW of heat, and thats not going to go away by passive radiation so . . . . nope. Of course if we are more carefree, like the Russians we can use nuclear fission. A 6kw reactor weighs 1000kg and you would need 12000kg of them for each and 80 also around a million Kg. Again more efficient than RTG but you still have a megadensity of heat to dissipate. They have a relatively high failure rate, the space watchers believe that one of them actually exploded. If you have 1000 on board you cannot risk the failure of even 1. RTG are much safer. So. . . . . . The big problem here is not the ION drives, its the energy production. Your solar panels take up about 0.7 hectacres (about an acre) for every millimeter/second of thrust, the RTGS will need more area for heat dissipation As I said you have these big floppy launches laden with panels and decay-driven devices. Battery Assist Ok as seen above thruster weight and surface area is not the way major problem, the thrusters could be telescoped like panels. For making a transfer, you need a pulse at AtPG of between 200 and 160 efficiently, kicking, but driving a retrospiral orbit wastes. Since near earth orbits are on the order of an hour, and you are in that ~10 to 15 % percent of the time thrusters are active and 85 to 90% of the time they recharge (50 if in low earth orbit). The other problem is that beyond 170 degrees the earth is blocking solar panels, this means more kicks with solar panels. But once a escape trajectory is achieved, power can be ramped down to energize the transfer, it can take days. So what to power productions look like with batteries. So now assuming that the density of Lithium Ion batter is 2 a liter of battery is 2kg one can achieve a nice 650Wh/L or 325 Wh/kg of battery (higher a conservative estimate), If we are using that battery .15h then they can produce 2166 kw and we only need then 32 kg of battery per N of thruster 2560kg of battery per 80N thus we are much better off stocking up on batteries than panels. This takes now our solar panel to about 0.1 hectacre per mN of thrust, but we are going to spend many orbits kicking out our space craft. So 540 seconds at say 0.002 m/s gives us 1 m/s lol. and to break earths orbit we need to add about 7000 kicks, actuall much less because as eccentrecity grows so does time spend in the kick zone. Of Course at Mars, recharging batteries will take 3 times longer. UNfortunately if you are going to use alot of lithium Ion batteries you better have an integrated cooling system to prevent them from overheating. Liquid fuel Oxygen assist We can see now that adding a few dV close to earth just to get the ship away from the earths shadow is advantageous. One possibility is an ION drive LEO/HEO shuttle system, something driven by VASIMIR might pick up ships and carry them an earth radius out and then let them enjoy longer orbital periods and longer times burning, this means adding some battery weight and thruster weight. Of course VASIMR not really a prototype transport system, so for now a good kick of LfOx into say high earth orbit, then let it burn continually into escape trajectory and on to Mars.

And your power supply? A mega toroidal dueteron-triton fusion reactor or a compact waterless fastbreeder reactor, or s superspammed 60% efficient superthin solar panel. Shrink VASMIR to 1/100th its current size, then you have enough power, just not enough thrust to go to mars in 39 days. So from Ion drives we have a more efficient magnesium (or sulfer any number of similar atoms) that can basically run circles around the currently used (not comparing with available, because there are alot of ion drives available that are more efficient than what is being used) but n this case the magnesium drives don't destroy the electrode quite as quickly. Metals can be packed much more densly. In the image I have spammed to Xenon tanks, but limited to the size of the tank (inefficiency of tank scale ups for pressurized gases) but because of this I have permanent infrastructure for the lattice. The thing about ION drives is that you do not have to come up with a new power supply, just select the most efficient for the task versus negations from their added weight and heating. The alternative is to shrink humans, if you could get their mass down to say 30 kilos, reduce their height and their sustenance requirments. IOW reduce the amount of mass spent on people, then you can reduce the amount of fuel, the amount of power spent on life support, while keeping power and energy constant. I think what people are doing here is this Someone said to mars in 39 days, but without saying how to get the humans back, so this has become the goal. Its a false goal, simple as that Mars is one Hohmann transfer which is about 200 days. Then Earth and mars go out of phase, so you have to wait about 2 years to go back into phase again, then another 200 days to transfer back. So if you are not talking about a plan that sustains a mission of 3 to 4 years, you are not talking serious. Taint no power supply capable of getting humans to mars in 39 days and back in 39days. VASMIR is great I think, it could be used for trash pickup operations and shuttling supplies back and forth to the moon where you are basically bursting power for short periods. Even hauling asteroid mining stuff should be a good mission.

Yep I know, the kerbal ION drives are ____way____ over powered, but they are also way under ISP. It makes landing possible but it undervalues the potential dV. However, I look at ION drives as way underpotentiated, based on latest research, even what is being used is about a half as powerful and a quarter as efficient. In fact Ion drive systems are the only deep space propulsion that actually works (proven unlike the RF resonance drive) that is as underpotentiated in terms of its current use. The Nerva, for all its worth lacks testing in a repeat use scenario, its basically been tested on a single burn, not a repetitive burn scenario after the engine is idled for 2 years. SO lets say thrust is a tenth, and of course earth has a GM/r at minimal orbit 10 times that of kerbin, if you can break orbit in a quarter of a pass then you could break orbit in 25 passes at perigee. This lack of power has more than just inconvenience, looking at Mars entry one has to do a near perfect transfer out of earth, otherwise dV would be to high to reverse a flyby trajectory, this removes 39 day scenarios, unless alot of gas is spent on pre-SOI burning. So this basically removes ION drives from consideration from short trip scenarios, this is why I keep saying, for the technology that we currently have, a mars trip is 4 to 5 years. It gives very good reason for separating the transfer processes Few people, lots of supplies, a small thin craft of the design I put forward. from the landing processes/reorbit processes. You may note that I went with a single person capsule and a halfweight crew supply package, it would be about the size of a cross over SUV on the inside, which means only 1 crew. The power supplies dissipate heat at the square of the radius whereas power density increases by the cube. This also has connotations, you can not scale up in 3 dimensions, a power package can get longer, not wider, which means craft take on extremely long dimensions, or excessive weight additions for radiators. So it is not smart to send crews in one big ship but many smaller ships. This can be considered an exploit, because you may note that NASA stacks the TNGs and you would have to have huge areas of TNGs running in a wide spanning lattice to power the craft without generating so much local heat as to destroy the power unit. I have a system of piping crafted now to do this, but its an exploit to launch it, because it has impractical drag, The only way to practically use TNGs is to build the lattice in space, and each unit needs to have a shield to protect the crew. Thereare are ways to do this, you can radiate the TNGs away from the capsule. If you have to bridge the TNG over several 100 meters of axial crossection, then its better to use expandable panels. The undeveloped technology is to embed the TNGs into the retractable radiator, the only problem there is keeping the cool until you get into space. So the basic problem is very simple, ION is great, wheres your power supply. But the basic idea of using ION power works, but my point is that its not one ship, its multiple ships to complete a mars mission.

Ion driven, 0.6 m/s2 post orbital transfer acceleration. 44 xenon tanks, This particular example 16 stock dawn (which are not particularly good state of the art drives, ISP is low) the central drive kicks out about 4 times the thrust. In the game is shows about 30,000 dV, each of the spherical xenon tanks has a scaled down decoupler, and so as tanks are emptied they are ejected into space, greatly reducing the weight. Basically its designed to go from 200 km earth orbit to minimal mars orbit and back to earth again, no means is provided for re-entry, provided the naut reaches a return trajectory he can transfer to the ISS or get a pickup ship for reentry. This craft has enough power to break kerbin orbit prograde in one orbit from 70k, starting at about angle to prograde of 250. Habitation, single lander and a stretch version of lander capable of holding 2 people, but for supplies and space for 1 person for 3 years. Energy. 15 oversized thermonuclear generators, capable of producing 120 times the PB-NUK amount of power, six solar panels provide to 100% power at mars orbit. As you can see even distantly spaced panels do not effectively gather sunlight at critical points. I have solar driven versions of this, but I had to add a whole series of aluminum framing pieces to get the needed solar panels. Eventually it becomes a launch stability issue. (IE 60m/s at 0MSL maximal to about 160m/s at 15000 kerbin meters) The Nucs are about 20 meters from the crew compartment are shielded by a lead-embeded metal disk, and 44 xenon tanks which scatter xrays. During interplanetary flight the panels can be close and the craft can be spun to generate centripetal acceleration, of course only about 0.3g, supplimental weights can be worn by travelers to increase stress on bones and muscles. The lander is sent in advance, a separate Ion drive at mars aids in the deceleration and loss of about 30% of the reentry energy, the lander has to provide the other 60% and fuel for take off and docking. Upon Mars orbit the lander docks with the transfer ship, and pilot boards, lands and when in orbit transfers back to the transfer ship and returns to earth. This ship comes with an additional docking port that can hold supplies from automated resupply ships from earth. However the travelers quarters are cramped, for a human this would be akin to living in an oversized coffin. Not really room for two people unless they are African pygmies. It also has the potential to provide a hub for a space station if a suitable return ship can be sent. Unlike other models the pilot does not need to move back and forth to special pods during solar storms, the craft is simply pointed head first at the sun. The shielding for the TNGs suffices to absorb and radiation the sun produces. Pros Do-able with alot of technology already available, as long as one does not have hopes for a return trip, see below. Cons Requires 3 or 4 craft Can only support 1 or 2 (pushing it) nauts The handwaving is in an ion-drive system that is both capable of slowing down a mars lander and returning itself to Mars orbit (otherwise it will be lost). Because as of right now there are No space ships capable of landing on Mars and returning to orbit. The more fuel one has for reorbiting, the less drag/mass is produced by that mars atmosphere. The lander weight needs to come down and some means of slowing down the lander so that it can retain adequate fuel for reorbit. I have made ION drive craft capable of landing on Mun (at very great risk) about 0.2g is the limit before a whole lot of things pile on top of each other. However is a small amount of fuel one can get enough momentum vertically for ion drive to capture orbit, again the fuel adds a hell of alot of weight. To circumvent this problem propose a martian moon as target. You ask a bunch of amatuers in a games chat room to tell you how to get on mars, don't expect rocket science. In case you are wondering: The lander extension is a blender craft (it weight almost 2 tons), it has a built in solar panel, because if stranding a craft dead out of electricity teachs a pilot anything, always keep that power flowing. The ion drive adapter carries two large Xenon tanks (total about 12K units) and has its own built in battery. The more efficient capacity is a trade off for the fact it is a single function item, it can only be used for ION drives. The spherical Xenon tanks are a blender craft. Each tank carries 7000 units. Presumably the drives could be replaced by a scaled down VASMIR (then nukes are not powerful enough) require much less gas (argon instead of xenon). Vasmir however is very heavy compared to ION drives. The sphere tank lattice is made up of 6 pieces (for scalability and because of the non concave collision mesh restriction for single parts) Every thing else that is not stock is a scale mod, there are no exploits, 2x rescale Factor get 8 mass, but on 4 fold power (e.g. ION Drive, or solar panels), Other than a trim of empty mass here and there for more efficient part design. One point the ION scale mod is primarily used for launch stability, so its better coupled to a 2.5 meter decoupler for the next stage.

Only 99.995% more of the 100000 signatures required to go. Im going to start a US gov. petition to name the undescribable fuzz deep in my belly button something, how about Smeelloo

I think you should have searched the archives, this is not even an old discussion and it has been discussed ad-nauseum (with all kinds of pukey noises to emphasize) here.

false dicotomy, ignored

pixie dust, hmm. At least if you are going to berate it, do so mindfully. Vasmir is powerful, unfortunately its heavy. and needs lots of power, we don't have source.

energy = mass times c ^ 2. The combination of e and m bend space time. Sounds wierd but this bending creates orbits, gravity is an observation. Its the same think as color being created by the eyes and brain, they are otherwise just hv. So to less precisely answer the question an orbit is a inertial reference frame, that precisely means that, discounting drag, i dont need to add kinetic energy of remove kinetic energy to keep the object in its orbit. Imagine that i am playing basketball on the moon, i shoot, the ball appears to be moving, accelerating toward the moon, this is how gravity appears to us. Instead the moons surface is accelerating toward the basketball. If i were to move all the moons soil from its path, it would be in orbit. The electrons of the moons soil are pushing the soil in the direction of the ball, the ball then hits the electrons and the ball is then in a non-inertial frame. Centripetal force is also a faux force, its actually the force of a rotor holding an object as the rotor spins. This is were newton primarily screwed up.