KerikBalm

Nope.... hohmann burns aren't possible with real ion engines at the given power levels*, so instead they do brachistochrone trajectories. You shouldn't be trying to do something that isn't possible. Because of the way ion engines work in KSP, we're always doing hohmanns, and never doing brachistichrones... its a shame. *sure, in theory you could perapsiss kick for your outbound, but that would take far too long, and you wouldn't be able to do a burn for capture at the destination... you'd go whizzing by, and fail your hohman transfer. With the OP'd "ion" engines in KSP, yea, you should do Hohmann's to maximize efficiency. But the point is that a real simulation of flight with an ion engine would have you doing a brachistichrone trajectory, not a hohmann transfer.

Don't you mean a payload pretending to be an engine?

The point is that you shouldn't be doing hohman burns at all with ion engines. What we need is an engine that works during time warp/affects "on rails" calculations. As it is now, the ion engine acts like a perfectly efficient ion thruster in the 40 MEGAwatt power range, (or more realistically, an ion thruster at 50% efficiency, with a power consumption of 80 megawatts). Good luck getting 10's of megawatts of power output from solar alone...

Umm, no.... "Deploy them as early as possible of course." This can cause problems if you are still significantly faster than terminal velocity - like rip your ship apart problems. Doing a full deplot of main chutes at 2500 vs 500 meters won't change your touchdown speed. I can't think of a scenario where 500m is not enough time for your main chutes to decelerate your ship, where an earlier opening would have helped rather than ripped the craft apart. Full deploy your drogues if your G meter reads less than 1 G while you are within 5km of the surface Full deploy your mains when your meter drops below 1 G again following the drogue deployment. "Even in the deepest valley of Duna with 20+ parachutes, you'll "land" at 10+ m/s. You always have to use your engines at least a little bit." Not true, I've done many completely unpowered descents. In some cases everything was fine, in other cases, my kerbals had to repair the landing legs. I've also dropped lightweight 1 way probes with no engines at all. However... if your craft does have engines, it may actually be better to use them, than to add more chuts and landing struts - its often better to spend 5-10 m/s of lander dV on touchdown, than to haul the extra mass of the chutes and struts to Duna. I never really considered using wings on Duna, as you can't use air breathing engines... but recently I was making an Eve mission, where I was going to deliver the ascent vehicle, and a science rover separately - and I figured... I should add wings to the science rover to make landing near the ascent vehicle easier. And... the wings would jsut get in the way when roving around, so I added decouplers, and attached the wings to those. Now it occurs to me, that using wings on Duna could remove the need for drogue chutes. Lacking the ability to use jets, any ascent would be a vertical climb and gravity turn as if there were no wings, so I don't think I'd bother with making a spaceplane design (not to mention a horizontal landing would require very careful landing site selection). So next I'm going to try out using wings on decouplers... as I figure it: My lander will be coming in pointing retrograde, with the landing chutes at the top, so I design my wings to be aerodynamically stable with the lander flying "backward" (I'll use and inverted small probe core, so I can click "control from here", and fly it without the reversed controls) - I should be able to pitch up and slow it down/flare, then pop the chutes and then quickly decouple the wings. It should be even easier than my Eve rover, as I was trying to land that thing still facing horizontal, and my parachtues weren't at the retrograde end.

Standard parachutes semi-deploy at almost exactly 9km on Duna. Drogues semi-deploy at almost exactly 10km on Duna. Of course you want them semi deployed ASAP to slow you down more before full deployment - drogues again help a bit here because their semi-deploy drag is 4x higher than the other chutes. The first chutes that open should be on the heaviest parts of your craft - ie if you have a full fuel tank, you should have some chuts on it, not on a part that is attached to it (as this will likely rip that part off your fuel tank). Even drogue opening can be a shock if you come in fast and deploy at 5km. I'd say full deploy on the drogues at 2.5 km, full deploy on the rest can come at pretty much any point after your drogue(s) open(s). If not using drogues, then stagger the openings, again starting with the chutes attached to the most massive parts first. This game really needs the radial drogue chutes to be stock parts....

Meh, you don't need to find all the anomalies or visit all the biomes before moving on to Duna. IMO, it gets a bit tedious to just do the same basic mission over again, just different landing sites - although trying to get to the canyons is cool- as is sending a rover near the intersection of 3 biomes, and roving around to get full science from all 3 (I think I did one in a crater, by a canyon entrance- get crater science, go into canyon, get canyon science, go back to crater, ascend torim, get highland science, return to ascent vehicle and transfer data). Once you've gone to minmus and landed and returned from the mun, why not go out further? As already mentioned, you can also go to eve, but anything that does more than dip into just the top of the upper atmosphere is going to become a 1 way mission real fast.... An eve orbiter/gilly explorer is quite feasible to do next. But IIRC, the Duna launch window opens before the Eve launch window, so I'm sticking with my Duna recommendation.

Well, with 23.5, there are near kerbin asteroids ot rendevous with, but I haven't tried that yet, it may be quite hard, I'm not sure. The next step is ussually Duna - it doesn't take much more dV to reach than it takes to get to Minmus (but you need to wait for the transfer window, and the transfer is quite long - in game time ofc, time warp makes it trivial). It has very little inclination, relatively low gravity/escape velocity - and best of all, it has an atmosphere- which helps a lot for capture (ie orbital insertion, so you don't just go whizzing past Duna) and landing. Yet the atmosphere is thin enough that it doesn't cost you all that much dV on ascent. Its pretty much the opposite of mar's atmosphere - mars has too little atmosphere to ignore (spacecraft can burn up if they come in too steep), but too little to be of much use (even with parachutes, a spacecraft will be going far too fast, and needs relatively powerful retrorockets). Duna's atmosphere allows you to land with just parachutes, assuming you brought enough, and land in the lowest depressions (where the atmosphere is thickest) - but you don't need to worry too much about it on ascent (although you should still ascend at terminal velocity). For most incoming trajectories , you want a perapsis between 10.5k and 12.5 to aerocapture into Duna orbit (it should give you an apopasis outside the atmosphere, and you burn there to raise your perapsis outside the atmosphere, or for a lander - do nothing and let the orbit degrade for no additional fuel use). Due to the added dV of taking off from Duna again, you should do it "apollo style", and use a lander that will launch and rendevous with the inter-planetary stage (or at least leave some fuel in orbit). - No sense in deorbiting the fuel you need to get from Duna back to kerbin, only to have to haul it back into orbit again. So in Kerbin orbit, perhaps you should practice orbital rendevous

The total amount of data you can get from each body is not reduced by transmitting data. But that doesn't mean the next return will be as much as the first return would have been without transmission. Ie, suppose you get 100 science for a return, or 20 for a transmit, and its possible to get 140 science total from repeated returns. You land, and transmit 20 science. There is now 120 science remaining to be gained. You do a return mission, this one gets you roughly 86 science, not 100 science. 86+20 >100 Of course, if you did 2 returns, instead of 1 transmit, and then 1 return, it would be something like 100 for the first return, and 29 science for the 2nd return - for a total of 129. Either way, you can keep sending missions to do returns, but the science gained will diminish each time. Its sort of like an infinite sum... 1+1/2 +1/4+1/8+1/16+1/32...... ... sums up to 2 science. Each return will give you a % of the remaining science to be gained. A transmission detracts from the remaining science to be gained, but the total amount is not lowered

There is no stealth in space. Blackbody radiation will be a dead give away

So... I'm contemplating installing this mod, but I see this statement: "wing pieces at wingtip make less lift and more drag than ones at wing root" This makes no sense to me? Making high aspect ratio wings will perform worse than low aspect ratio wings? 0.o ?

Or just match its inclination before even starting the transfer maneuver.... This doesn't work for other planets, but it does work for minmus. Set Minmus as a target, place a maneuver node at the "ascending" or "descending node", at that manuver node, set a burn normal or antinormal (ie pointing "up"/north, or "down"/south) until the ascending/descending node reads 0.0/ NaN/ starts to move (the more precisely placed your maneuer node is, then the closer the point where the asc/desc nodes start to move is to when you'd have perfectly matched inclination, if you placed it perfectly, then the nodes will suddenly swap as you make your burn a bit longer) *execute the burn*, possibly repeat if your inclination is still off by more than say... 0.5 degrees (ie look at where the asc/desc nodes are post burn, do another correction burn at that point) *transfer to minmus as you would to mun with a simple appropriately time prograde burn, and retrograde capture burn.

A 1kg iron weight falls as fast as a 1000kg iron weight, all you need to do is see if these fall up or down.

Since gravitational attraction is a property of mass, and anti-matter still has mass, why wouldn't there be a gravitational attraction. Antimatter is essentially the same set of particles, with opposite charges, right (perhaps this is oversimplified), but I can't imagine why there would be gravitational repulsion, unless we were talking negative mass-mass. Furthermore, can't such things be measured already?

The concept of getting gravity assists from the point of launch seems weird to me... it seems like a losing proposition, can you actually get more dV out of it than the dV needed to set up the maneuver?

Thats why some shows get around it by having people view "one possible future" You know, parallel universes, exponentially increasing in number with each interaction (either at the quantum level, or a less well defined level based upon the decisions of conscious individuals). Thus many possible futures exist for any given time... of course in such shows its typically only 2 (despite the disclaimer), the one that will happen if the "vision" is ignored, and the one that will happen if the "vision" is followed. Or its only 1 - the one that happens while trying to avoid it (as in Oedipus Rex)

Let me sumarize: Hurr durr, I don't understand what I'm watching video 5 Video 5 shows an offset gyro rotating about a plausible CG. The purpose of the experiment is to show that it rotates about the CG, the only misunderstanding is on your end. You claim to do the experiment, but offer no proof. So I'll just claim to have done the experiment 1000x more than you, and generated data disproving your position

Its too hard and inefficient for me... I just build SSTO lifters. Its easy enough to build a SSTO spaceplane that can lift large payloads (my most recent was 83 tons) My "fully reusable Zero Debris" to duna missions involve: * Large spaceplane lifts an LV-N powered interplanetary transfer stage and a SSTO Duna lander. * Large spaceplane lands, Interplanetary stage goes to Duna * Lander + IP stage begins aerobraking as one unit * Lander separates and lands while, Interplanetary craft circularizes into low Duna orbit. * Lander launches, docks with IP stage, and refuels * Lander remains in orbit for future use, IP stage returns to kerbin * IP stage aerobrakes and circularizes. * Large Spaceplane refuels the interplanetary stage Everything is reusable, but trying to move them all together as one craft is... IMO wasteful and inefficient I could bring the Duna lander back with the IP stage.. but what is the point? Much more elegant IMO, to leave a fully fueled lander ready for use by the next mission (so the next mission can simply bring a fuel tank to set up a fuel depot, rather than another lander) For sure, I can get my spaceplanes to the mun, or to Duna... getting them back is another story... No spaceplane I send to laythe returns. Every SSTO lander I make, I leave in orbit (preferably fully fueled, or at least fuelled enough to de orbit and then get back to orbit) rather than carying it back (I'm assuming spaceplanes are the most mass efficient SSTOs for use on Laythe, I also like that they launch themselves, and I only need to launch additional fuel for them/something to push them to laythe [some have enough fuel left over to reach orbit from laythe's surface, and thus for a single mission just need a boost, not a refuel])

I'd also say it happens at engine cutoff, and ends upon reentry. I suppose for suborbital flights, it could possibly be more gradual, if the engine cuts off while there is still noticable atmospheric drag(of course this would result in going from positive Gs to slight negative Gs, and theb back to zero as the craft ascends through the atmophere and out into space) - but that wouldn't happen on an orbital flight, so engine cutoff would occur last.

For sure, most of those hydrocarbons involved biological processes. Hence the key word "all". The question is if you can get relatively long chain hydrocarbons abiotically, and if any such abiotic hydrocarbons are still present on Earth. For example: http://www.osti.gov/scitech/biblio/7052010 There are abiotic hydrocarbons on Earth - in the specific case above, that abiotic methane is only 0.02%... but it is there. I will agree the consensus is that a biological origin is the predominant origin. But on a lifeless world, where the much faster biotic process is absent, could an abiotic process still produce significant amounts of high MW hydrocarbons? As I said, Titan may be a nice test case to see what sort of complexity you can get in hydrocarbons without biological processes. Of course, #1) It will be very hard to see anything that is not on the surface or just a short distance below it #2) Due to its lower mass, the pressures will not be as great #3) Its much lower temperatures will also affect this. #4) There's a chance that biological processes are at work on Titan, and that would be so cool that nobody should mind that our test case is inapplicable Yea, I was being too imprecise, I'm mainly just talking about generic "hydrocarbons" Well, I'm not sure why you mention this. #1, I didn't mean to imply that the microbes would be synthesizing compounds at the same place that the petrol is being formed. I shouldn't have specified deep underground at all - however, in the case of a "lush world" bs a world where the surface is sterile (as is likely the case on mars), you could have a deep biosphere responsible for the presence of the petrol, but the world would be far from "lush" #2, cyanobacteria, and not forrests may concentrate and synthesize the hydrocarbons - so accepting a biological origin, hydrocarbon deposits do not mean a world once covered in forrests, it could be "slime" covered. (again, a not so "lush" world) #3, the abiotic origin hypothesese have the petroleum form, then migrate upward, where bacteria then feed on it and alter it. Its then a question if the hydrocarbon originated from within the earth, or from buried biomass. No bacteria would be involved at the origin. Additionally: http://www.pnas.org/content/99/17/10976.full Clearly a) Abiotic hydrocarbons exist (Methane, Ethane, as on titan) At sufficient pressure, abiotic hydrocarbons can form alkanes up to at least decane, and also forms alkenes and various other variations. Evidence for a biological origin does not exclude a parallel abiotic process. The biological process may be much faster and dominate, and it may also "reprocess" the abiotically produced hydrocarbons, obscuring the origin. The biomarkers are clear, but abiotic origins are still plausible, and thus for the purposes of this discussion, if Eve had hydrocarbon lakes, we could not conclude a history of life (particularly given that Eve's gravity would result in even higher subsurface pressures)

Light isn't needed, but it is a very abundant energy source. Its also worth noting that we cannot resolve extra-solar moons. So we can't see anything that may be warmed by tidal flexing. We can't deterine core composition, so we don't know if a planet has a hot core, kept warm over long periods by radioactive decay. The only energy source we can be sure of at the distances involved, is light. We can see the "parent" star. We can't see the rest of it. So naturally, that is where we look. I would very much like for more focused missions to be sent to mars, and missions to be sent to Europa/Enceladus. I have a suspicion that we will find both to be quite sterile (or at least lacking alien life*)- yet potentially habitable. The conditions neccessary for life to start, are not the same as the conditions that life can survive in. I can't help but look at mars, and think... where is all the evidence of life? Its hard to look at this map, and not think that Mars had an ocean: http://upload.wikimedia.org/wikipedia/en/1/1d/Mars_Map.JPG Or you can look at pictures like this: http://upload.wikimedia.org/wikipedia/en/9/94/Eberswalde_delta_plain25.jpg Curiosity came across a streambed that was flowing long enough to have pebbles rounded by erosion Numerous sedimentary rock formations have been found Water was flowing, there were large amounts of it, no question. Rather old craters in the martian highlands still appear crisp http://en.wikipedia.org/wiki/Hesperian - from the time period when wars was drying up, but still seems to have had standing water Even old riverbeds are still there... so it seems likely that erosion isn't so much that fossiles wouldn't still be around. http://en.wikipedia.org/wiki/Geology_of_Mars#Inverted_relief Some of those riverbeds, do however seem to have been affected significantly by erosion - in that apparentyl everything around them eroded, but they remained resistant to erosion, due to the clays and such being cemented together by exposure to water. Our rovers have encountered numerous places where water was obviously present in the past. Now... I'm not expectng us to find some fossil fish like thing, even if they were there, 3 rovers could easily miss signs as rare as those. If one looks at old seabeds and such on earth, the signs of life are easy to see. Before the cambrian explosion, microbial mats and stromatolites were everywhere. http://en.wikipedia.org/wiki/Microbial_mat http://upload.wikimedia.org/wikipedia/commons/9/92/Runzelmarken.jpg Now stromatolites and microbial mats are only in a few places: http://upload.wikimedia.org/wikipedia/commons/1/1b/Stromatolites_in_Sharkbay.jpg http://en.wikipedia.org/wiki/Microbially_induced_sedimentary_structure - because more complex organisms eat them And then there are the old banded iron formations http://en.wikipedia.org/wiki/Banded_iron_formation If photosynthesis ever evolved on mars, given that no higher organisms would be around to disturb them (ie direct consumption burrowing action, covering them and blocking access to resources, etc), then basically everywhere that had standing water should have been covered with a microbial mat or stromatolites.... and conditions on mars are such that there isn't much appreciable erosion... Where are the banded iron formations? Where are the stromatolites, where are the fossilized microbial matts? If our rovers are looking at ancient lakebeds, assuming no higher organisms evolved that ate mats of cyanobacteria like organisms, and the lakebeds were habitable all the way up to the point that they started drying out, if photosynthesizing bacteria were there, it should be obvious. Photosynthesis evolved very quickly on earth, and it would be strongly selected for.... so I'd guess the same would be true on mars if it had life. Yet I still have an idea... what if those "inverted relief" features aren't simply clays cemented together... what if the feature that makes them resistant to erosion... is that the riverbeds and deltas were covered in a massive microbial mats, which are now fossilized and at the top of these inverted relief formations? These same microbial mats are what seem to have preserved almost all the fossils of pre-cambrian multicellular life. One explanation for the disappearance of fossils of almost all the precambrian multicellular life in the cabrian and higher, is that the microbial mats were gone, and thus the main method by which these fossils were preserved is also gone. If it were up to me, we'd send a rover to go investigate an inverted relief formation... say in an old delta. If we don't find fossilized microbial mats there, we'd stop looking for life, and conclude that the requirements for conditions to support life are much less stringient than the requirements for conditions to start life.

I am unconvinced(and there is scientific dissent) that the oil on Earth is actually all a result of "fossil fuel", especially if we are talking multicellular life. Titan shows us strong evidence that small hydrocarbons can exist abiotically. We already know the heat and pressure of Earth's core can form carbon into very large covalently linked molecules (indeed, a diamond is a single molecule). I see no reason to think that primordial hydrocarbons could not be turned into larger hydrocarbons abiotically. Sure, rapid forrestation, and then burying of forrests, as in the carboniferous, would lead to large concentrations of buried carbon, and could result in more being formed. Also, microbes deep underground could synthesize larger compounds to accelerate the process. - But I doubt lush forrests, or even life at all, is required to make various heavy hydrocarbons - ie "oil" A "curiosity" type mission to Titan would be very interesting, as would a submersible on Titan.

Am I the only one whom is reminded of arguing with creationists? One side brings many facts and sound logic, the other side blatently misrepresents the facts and uses bad logic. He's still talking about a video where you can clearly see the tower revolving about a point between it and the gyroscope, as expected. The only thing that changing the relative masses of the tower and gyroscope will do, is move the point that the tower revolves about - either closer to the tower, or closer to the gryoscope. Thus light vs heavy tower would only change the radius of the revolutions of the tower. The video used masses such that the radius is easy to discern - it doesn't much matter if the radius is 1cm, or 10 cm, both can be clearly seen (but if it was 10mm, it would be too hard to see). Many labs weren't even interested in debunking the "arsenic life" paper, because the conclusion was on such a shoddy foundation. I'm surprised a lab at cambridge (note that its not as if the entire university oversaw this) would even bother to put any effort to debunk this. Why... they might as well be trying to debunk some quack claim of alchemy. Its Russel's teapot all over again. The burden of proof is on you Momentus. Showing us a video of a tower of unknown mass revolving around a point that is quite plausibly the CG does not support your claim. Referring to an experiment of a tower with legs quite capable of digging into the ice it is sitting on, does not support your claim. We have no reason to believe your claims, and no burden to disprove them.

Well, we can speculate, as in the wikipedia link, on other solvents, other types of chemistries, etc. You made a specific claim about life forms we had already identified, and that is what I have an issue with. I have no problem with speculating about life that uses ammonium or methane as the solvent, for example

"Temperature, light, pressure, moisture, etc" You still have not provided any examples beyond the commonly accepted limits

Actually, our understanding of how life got started is much better than it was even 10 years ago. The RNA world hypothesis has come together nicely with recent findings of RNA ribozymes, which have been getting (or rather, the forms we have evolved recently) more and more advanced. We now have RNA ribozymes that can copy other RNA sequences longer than themselves. As to your link, all of those cannot "survive without one or more of the commonly-accepted 'prerequisites' for sustaining life." They all require H20, and C, H, O, N, and P. I challenge you to point out something that they can survive without, that you would consider a "commonly-accepted pre-requisite for sustaining life" For anything you point out, I gaurantee I can find papers showing it was well known to the scientific community that it was not a pre-requisite. Also: http://scienceblogs.com/webeasties/2010/12/05/guest-post-arsenate-based-dna/