Zhetaan
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Are you planning on going to Duna and then continuing to Jool as a sort of little grand tour, or will it be two separate missions?
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@canisin: You can add a CLS module to the reaction wheel or turn CLS off when you're at that station, I suppose. I know that CLS has an off button mainly intended to let you evacuate old stations if you decide to install CLS in the middle of a save, but nothing prevents you from using it at any other time. Given that this appears to be CLS doing exactly what it was designed to do, it all depends on the point at which you think you go from setting the parameters of your play style to cheating at solitaire. For what it's worth, if you're going to play this game, then you're going to have to roll with the punches. The fact that you effectively punched yourself in this case just means you should have a good laugh and move on, whether you decide to bring the large construction crew, de-orbit the module and send a replacement, or do what @bonyetty suggests and suddenly remember that you meant to install it that way--OH&S is important, after all. You wouldn't want wild goo just floating about in the crew compartment.
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@HebaruSan: True, but if that happens, the solution is to back up a step and refine it again. The point is to break up the transfer into manageable pieces; however, just as everything else in KSP is an approximation, so too is breaking up the transfer planning. There is no single action you can do that affects only one variable, so the only way to break the problem into manageable pieces with the tools at hand in stock is to work out a way to limit the effects of those changes on all but one of the variables and then make corrections to the approximation. It's Newton's method, in space.
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Not necessarily: it's fairly easy to set up a node to go efficiently to any planet's orbit without using mods. For example, let's go to Duna. Start with a spacecraft that's in a low Kerbin parking orbit. It doesn't have to be the interplanetary vessel, though of course that would help. Create a node there and stretch the prograde modifier to get a transfer orbit that reaches Duna's orbit. It's helpful to know whether you need to start your burn on the daylight side, but if you set up the node and start pulling on prograde, you'll figure that out on your own very quickly. Tweak the transfer orbit by sliding the node along your low Kerbin parking orbit and reducing prograde to keep the apoapsis at Duna's altitude. This can be done in two stages: slide the node and observe whether the apoapsis rises or falls. If it falls, go the other way. If it rises, go until it reaches a maximum and then reduce your prograde to drop the apoapsis back to Duna's orbit. This will get you close, but changing your prograde burn will require you to slide the node a bit more. Keep doing these two steps to refine your burn delta-V until you cannot reduce it further without dropping the apoapsis below Duna's orbit. Now you have your transfer time and delta-V. Then it's just a matter of clicking the +orbit button on that node so the arrival time at Duna's orbit occurs when Duna is at that point on the orbit, and you've found your window. I'll grant that it is tedious, I'll grant that it solves for both phase angle and ejection angle without telling you the values for either, and I'll even grant that it doesn't do anything about inclination corrections, but it does find the window--and since the solar system always starts in the same configuration on Day Zero, you only need to find the transfer window once. The trick to it that makes it difficult for people to do it is that they usually don't separate the idea of reaching Duna's orbit efficiently from the idea of reaching the planet. They try to encounter the planet first and then play with the node to make it more efficient, or else launch first and tweak later, but that's not really how it works. The important thing to remember about interplanetary encounters is that transferring to the orbital altitude you want is all about the initial burn; timing doesn't matter because if you do it correctly, then you will reach the correct orbital altitude whether or not you intercept anything there. Intercepting the destination after that point--once you have a burn that puts you on the correct orbit--is then a matter of timing alone because you already have the burn. To illustrate with an example that is in Kerbin's sphere of influence (and thus easier to see without a lot of zooming), I don't know how any of you set up encounters with the Mun, but the way I do it is to set up a node to go to the Mun's altitude first, and then slide the node along my parking orbit until I get an encounter. I may make minor tweaks after that but for the most part, initial burn setup is done before I have the encounter. The equivalent to the less-efficient way most first-timers try for interplanetary is to start with a node that gets the encounter and then start tweaking that encounter (by both changing the amount of prograde and sliding the node) until the required delta-V stops decreasing. That can work sometimes but it involves solving for two variables at once (burn start time and total burn duration) and it gets confusing--especially if you hit the right value for one variable but not the other, and you don't know which one is correct. The way the original poster tried for Eve is equivalent to burning for a transfer that takes you up towards the Mun's orbit (possibly one that gets close to an intercept, though that was not made explicit), waiting for an hour, and then trying to get an encounter. I'm not saying that can't work but it's horrifyingly inefficient.
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I just experienced this one and wanted to mention it to the forum before I submitted the report on the bug tracker. Since my first-pass search didn't give me any results, I assume that it hasn't been raised before. It's also important to note that I'm using a modded install; I don't want to cause trouble for the devs if this is a mod problem rather than a stock problem. I'm still on v1.2.2, so I do not know whether this has been fixed in v1.3, but I saw no mention of it in the release notes. I had one tourist contract for a Minmus flyby mission and sent up a craft to complete it. While that craft was in flight, I had another tourist contract for an orbital mission, so I sent up a craft to complete that, as well. I recovered the orbital mission, switched to the flyby mission, and noticed after the flyby that the mission parameter did not complete; further checking showed that this was because one of the tourists assigned to the flyby was not present on the vessel. Since I verified that all required Kerbals were present before I took off (I made that mistake exactly once--it was a Jool visit), I was perplexed until I looked even deeper to discover that one of the tourists on the flyby shared the same name as one of the tourists on the orbital mission. It's fairly clear that what happened in this case is that the name generator (I assume by pure random chance) returned the same name twice. Since Kerbals appear to be indexed in the persistence by their names, when I took the second contract, the game created that tourist Kerbal in the Astronaut Complex and effectively erased the original from existence. My question is to ask whether there is some kind of check against duplicate names in the stock generator--hence my preliminary fact-finding here in the modded support forum. If not, then I'll add it to the tracker and let the devs handle it. Obviously, reproduction is an issue, though I suppose it could be done with a heavily-redacted generator file.
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You know, that anomaly near Jool in the Kerbahashi Maru did look a bit like a marshmallow.... 'There is no Duna; there is only Jool!' Then in the sequel, Our Heroes tap into the good feelings of the Positive Forum Movement to defeat the Big Bad! Where's @Deddly for this? It works on so many levels!
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- totm mar 2024
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An additional, comparatively minor argument for refining on the ground is if you are doing any orbital manoeuvring and need monopropellant (which is likely since you're running a lander back and forth), then although the large ISRU will still take one unit of ore to produce two units of monopropellant, the monopropellant itself is less dense at 4 kg/L rather than liquid fuel and oxidiser's 5 kg/L. This makes the refined product substantially less massive than the raw ore: twenty percent mass savings is plenty of reason to refine on the ground.
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Interplanetary transfer from the Mun
Zhetaan replied to Lunar Sea's topic in KSP1 Gameplay Questions and Tutorials
@Cpt Kerbalkrunch, @HebaruSan, @Lunar Sea: @OhioBob did a rather exhaustive analysis of savings for various starting orbit altitudes. I know it's not the original question, but since the discussion is turning that way, I thought I'd supply the reference. It's something to consider if any of you want to make a serious effort at understanding the physics behind orbital refuelling stations, advanced interplanetary transfers, and the like. This also talks about the subject, if you're interested, and it has some very interesting mathematical plots (including ones that choose the best of either a direct prograde transfer or an LKO dive). -
Ultimate Moho 6 Expedition
Zhetaan replied to antipro's topic in KSP1 Gameplay Questions and Tutorials
@antipro: One thing I'll add that I did not see anywhere else in here is that the contract says to land on Kerbin. This means that you have to land on land; splashdown does not count. I've seen a few posts in the Gameplay Questions forum from people who did ultimate tours, returned to Kerbin, and found that the contract did not complete because the game considers the KerbinSplashed state to be different from KerbinLanded. Of course, this only came up after the craft was recovered, so I'm sure there have been more than a few ragequits over it. I don't know whether they've fixed that in new updates, but it's better to be safe than sorry. I'm sure that goes for Eve, as well, but since you're generally looking for a mountaintop landing on Eve, it's not really something you'd need to concern yourself with. -
@Chads: The numbers are bi-directional, as others have said, but you were correct, too. The other tricky part about these is understanding that most of the maps are Kerbin-centric, which is to say that they are easiest to understand from the perspective of going from Kerbin to another planet. With a little work (mostly craning your neck), you can grasp the necessary return delta-V (the trick here is knowing that you're not necessarily starting from the surface of the visited body; you may be starting from orbit), but assists and moon-to-moon transfers can't be read from the basic map. Keep that in mind if you ever decide to try for a grand tour or multi-planet flyby. For example, let's say that you want to go from the Mun to Minmus (or vice versa), perhaps to train a crew or for a couple of tourist contracts. The delta-V map you have doesn't have good answers for that transfer: you don't want the LKO-to-flyby transfers because you're not starting from LKO, but at the same time, the flyby-to-orbit numbers are based on an orbit that begins at LKO. Either way, it appears on the map as though the transfer should take up to 500+ m/s, but in reality, you can get a Mun-Minmus transfer every eight days or so for between 210 and 220 m/s. Does that sort of issue arise very often? No. But that's how it trips you.
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Yes, I recall that it was extremely obscure; several million places in base-11, and it was nothing more than a raster of a circle. Though what was specifically hinted at was that the answers are in the transcendentals, of which pi is only one. In fact, it can be proven that most numbers are transcendental. That raises interesting questions regarding the sines of weird angles and natural logarithms of the entire integer set--the very idea of answers hidden in transcendentals itself is almost enough to make most sane people quit right there. What if we had chosen to adopt tau instead of pi? It's maddening--and it's a good thing that Contact is fiction. Edited to add: Now that I think about it, though, it does put the whole SETI search into perspective. Maybe Fermi was wrong and there is no paradox.
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Thank you. I was trying to figure out what else this was tickling in my memory, aside from the obvious. Though I think @Cydonian Monk would be better served following the film rather than the book; eighteen hours of recorded static would be much easier to do in KSP than finding rasters in the millionth place of pi, what with double-precision numbers ending at--what was it, sixteen places?
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The thing to remember about that warp drive is that it conserves your velocity; you can go anywhere quickly, but to be able to stay there requires finesse. Imagine, for example, beginning in Kerbin's orbit and then going to Jool--but when Jool is on the opposite side of the sun from Kerbin. Kerbin is moving with an orbital velocity of about 9.2 km/s, and Jool is going to be moving at 13 km/s relative to that. So far as Alcubierre warp fields are concerned, the overall effect is essentially the same as popping from Kerbin to Jool via teleportation, which means that you will get to Jool's system and then stay there very briefly as you fly out of it at 13 km/s. To cope with that velocity, you have to essentially split the magnitude from the direction and manage them separately. For the example, Jool is going at a slower speed (because it is farther from the sun) but in the opposite direction (because it's on the other side of the sun from Kerbin): if you went directly there, you'd need to stop for 9.2 km/s, turn around, and accelerate by the 4 km/s you'd need to match. You can do this much cheaper and faster if you only need to shed 5.2 km/s and can change direction. The warp drive cannot do that--its essential function is to separate the vessel from the normal rules of spacetime--so that means you will need to use a combination of normal flight with superluminal flight to achieve your goal. However, warp drive can change location very easily--this is, in fact, its only selling point--so if you can use a gravity well to alter your trajectory, you'll get where you need to go so long as you go to the gravity well first. More gravity makes a quicker change, so that means going to the sun. Make a note of Kerbin's tangential velocity direction with respect to the sun and warp to a point above the sun's surface (not too close, of course) where that velocity vector points straight radial out with respect to the sun. This is going to be a line that crosses Kerbin's orbit around a quarter of an orbit ahead. The idea is that if you warp to a place where your velocity carries you directly out from the sun, then the sun's gravity will slow you down without changing your direction. Since gravity drops with the square of the distance, you may want to keep warping back down in order to get the quickest deceleration rather than let your speed drop in one long coast. Once you've lost 5.2 km/s, warp to a point near (again, not too near) the sun such that you are directly between it and Kerbin. Now your velocity is no longer pointing straight radial out; instead, you want it pointing prograde. Orbit the sun until your direction is parallel to Jool's direction, then warp to Jool. Now you will have matched both direction and velocity with Jool, and any further corrections should be fairly simple. You may want to change direction first instead of magnitude; you'll have to try it for yourself. To return to Kerbin, the situation is reversed; warp to a point high above the sun, but falling directly radial in; you'll pick up speed as you do. Keep warping back out before you broil yourself until you've built up the needed speed. I leave the matter of inclination changes as an exercise for the student. You may note that a typical Hohmann transfer accomplishes this effect by combining the direction change and the speed reduction over the course of one very long flight, and for roughly the same amount of speed change (an ideal Hohmann to Jool is about 5 km/s). Since the warp drive won't allow that, you have to get creative.
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Interestingly enough, Heinlein never really got to the point of discussing cooperative, interactive fiction, such as would be found in any kind of a role-playing game. Total chaos is my best guess for what those places would be like. Can you imagine a world where griefers are flesh-and-blood people? I imagine that the only artefacts recoverable from such a place would need to be stored behind leaded glass on account of the radioactivity. Personally, I'd like to see what happens with the 'choose your adventure' stories. However, yes, by that interpretation, Emiko Station would be stuck in limbo if you didn't complete it--this point was discussed. One of Heinlein's characters met a story character that she created (how's that for surreal) and, having met him, shaken his hand, and known him for being a living, breathing person, had a problem with the idea of continuing to write the story, which of course was building up to an heroic sacrifice where the hero died defeating the villain. Who wants to write about the death of a main character after learning that doing so is incontrovertibly murder that results in very real death? However, it was also pointed out to her that if she didn't do so, then she was denying that character the fulfilment of his great purpose in life and dooming him to a stagnant existence where he does nothing but exist, which would be the worse crime of imprisonment without dignity. Also, denying the hero his victory would also deny the villain his defeat, and since the villain was in on the truth as well, that meant that he continued to be a very real threat to the world. More than anything else, the burden and duty of an Author (always with a capital A) in Heinlein's World-as-Myth is to finish the story. Of course, we're not Heinlein characters, so go take care of your cat.
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Heinlein did something a bit similar at the end of his career: he introduced a concept that he called 'World-as-Myth' (as opposed to 'World-as-Logic') wherein every reality is the work of fiction of another reality, and the solidity of that reality was largely rooted in the readership and the retelling, which was the myth part. In other words, if I write a rubbish piece of fiction for my creative writing homework, the reality exists, but it's tenuous at best. On the other hand, if I write an award-winning, long-running soap opera with millions of viewers, then that reality exists just as much as yours and mine...and is hideously predictable, but it exists. Of course, this meant that the most beloved and enduring stories were not only real places, but that they were also the most likely places that one would visit: hence holiday trips to the Land of Oz and the like. This also meant that for any given set of characters who were in on the truth, there were three totally different classes of antagonists after them: there were the competing groups of people who, like them, were in on the truth but had different views on how to apply the knowledge; there were the Big Bads from all of the stories that everyone's character was a part of (Oz was favoured for holidays because its stories had run through the bad guys; it was a fairly peaceful place that enjoyed the serene tranquillity of Happily Ever After); and there were the Authors themselves, in the sense that no one has plot armour, and in this case, such would need to manifest as literal armour (Oz was favoured for this reason, too, but unfortunately, it also meant that Oz was going somewhat stale). It was an interesting concept that was mostly explored in The Number of the Beast and fleshed out further in The Cat Who Walks Through Walls. For my part, aside from the fact that it was interesting, I thought that it wasn't really thought through--not to needlessly disparage Heinlein, but deliberately introducing a system that is by definition logically inconsistent is going to make holes in the story that cannot be plugged. One example would be characters who are brought into World-as-Myth and then rant about superstition ... that, because it is believed, makes it true, which would reinforce that belief, but of course that point did not make it into the story. Another would be the unanswered question of pretty much anything Lovecraft and where it fits into the larger world, given that so much of Lovecraft's work ends rather badly for the world. One may imagine a grand effort to burn all horror writing in order to save the world ... and anyone who knows anything about Heinlein knows how he felt about book-burning (hint for the uninitiated: he was not a fan). That being said, on the other hand, it all came down to Heinlein's ideas on solipsism, so I suppose perhaps that anything inconsistent in the world only goes to show that the human mind has to process logical inconsistencies all the time. This time, it's all writ large because those inconsistencies are projected onto the very fabric of reality--but this is all why time travel and the like gives me a headache. On the gripping hand, there are some hilarious ideas in there, too. One could imagine the original E.T. universe at war with the remastered version over which one was correct, and of course the original would win that fight because they have shotguns, whereas the remastered characters are armed only with walkie-talkies....
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PB-NUK Radioisotope Thermoelectric Generator
Zhetaan replied to Eagleye's topic in KSP1 Gameplay Questions and Tutorials
@Eagleye: For some more detailed information, the RTG works in the code by having electrical output but requiring no input; it just creates ElectricCharge from nothing. As far as how to use it, it has nodes at the round ends and it also surface attaches, so it can go anywhere on your rover. Just stick it on and it will work. It is heavier than every stock solar panel but the Gigantor, and its power-to-mass ratio is the worst of any electrical part. It's extremely expensive--though you play sandbox so that's not a problem for you--but the point is that the comparatively free power is the only advantage of an RTG over other generators. Solar panels work with 43% of their LKO-rated output at Duna, 11% at Dres, 4% at Jool and 1% at Eeloo. They get better as you get closer to the Sun, going to 191% at Eve and 668% at Moho, but you may want RTGs there, too, because solar panel output drops as the temperature goes up or as the atmosphere gets thicker, so you won't see anything like double output on Eve's surface. Moho's night lasts for nearly 62 days, so for a rover there it makes a lot of sense to be less dependent on solar power. Personally, I tend to use RTGs as supplemental power units to take the edge off of the solar power requirements. For example, a Gigantor at Jool still produces 57 EC per minute (the RTG produces 45), but when used in combination with a solar power system, you have to consider that the RTG nullifies some of the battery requirement for the night side, not just the solar panel. For example, let's say you're in low orbit of Jool, which has an orbital period of close enough to one hundred minutes. If I have electrical equipment that requires, say, 100 EC per minute to operate, then I use up 10,000 EC per orbit. Two Gigantor solar panels, at .3 tonnes each, will provide that power on the daylight side, but for the night, I need 4,000 EC of storage (the darkness time on that orbit is about forty minutes). A Z-4K provides that at .2 tonnes, for a total electrical mass of .8 tonnes. But wait, that's not the whole picture! Two Gigantors produce 114 EC per minute at Jool, but my equipment uses 100 of that, so I'm only devoting 14 EC per minute to charging the battery on the day side. That gives me 840 EC in the battery when I go to the dark side, not 4,000. Adding another Gigantor gives me a total of 4,260 EC per daytime per orbit to charge the battery. This means that we need another solar panel whose only job is to charge the battery, and the total needed mass is 1.1 tonnes. If we use an RTG, we get 45 EC per minute forever. This means that we can figure the electrical needs based on a 55 EC per minute requirement. One Gigantor provides that at Jool (with only 2 EC left over), and the reduced load means I only need to store 2,200 EC to last the night. Two Z-1K batteries and one Z-200 give this for .11 tonnes. A second Gigantor (plus the 2 EC left over from the first) provides 3,540 EC every daytime per orbit; the total electrical system is now .08 for the RTG, .11 for the three batteries, and .6 for the two Gigantors, for a total of .79 tonnes. If I use two RTGs, then I can switch the batteries with a Z-400 and get rid of one of the Gigantors, for a total mass of .48 tonnes--this is less than one half the mass of the solar-only system. Also on the subject of Jool, remember that every one of Jool's moons is tidally locked, so the nights get quite long on Bop and Pol. Any surface rover will need you to think about the means of power generation if you want to use it at night. When we go to Eeloo, note that a Gigantor still provides 33 EC per minute, so it does have some use there, but Eeloo is past the point where the stock RTG outperforms the stock solar panels. At Dres, on the other hand, a single Gigantor provides over 162 EC per minute. At a 12 km orbit, you have an orbital period of approximately 45 minutes. The darkness time here will be in the order of 15 minutes. This requires 1,500 EC of battery if we're using the same 100 EC per minute rocket we sent to Jool, which we can get for .075 tonnes. RTGs mass at .08 and you're already down to one solar panel, so there's no way to improve on the solar-only system with a hybrid as far as orbiting craft are concerned--but three RTGs will power the craft on their own at a mass of .24 tonnes, rather than the solar system's .375 tonnes. It will also cost sixteen times more to save 135 kg, but that's not a problem for you. -
So long as it can't make orbit, the landing part will happen pretty definitely anyway.
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- totm mar 2024
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Given the state of affairs at the end of chapter 19, I for one am intensely curious about what you're going to put in the interlude. I will say this, however: if you're going to call them 'Our Heroes', then you'll need to write those recaps in the style of old radio serials. This could be fun: '<Zzt> When last we left our heroes, they were held in the grip of the evil Ship. From. Outer. Space!!! <Organ suspense notes> As they stare danger in its scruffy face, we wonder: Will this be the end? Will Bill code another miracle? Can Valentina lead her crew to a new dawn out in the cold light of Jool? Find out on today's episode of Kerbfleet in the 1/25th Century! <Orchestral fanfare> ...And now a word from our sponsors. <Zzt>' Public sector, eh? Does that mean that if you keep climbing the ladder, one day we'll refer to you as Kuzzoner?
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- totm mar 2024
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We should all probably be cautious when someone who calls himself Mad Rocket Scientist starts citing other mad science stories, but I do want to make one point: one of the thematic elements in Strange Case of Dr. Jekyll and Mr. Hyde was that while Mr. Hyde was pure evil, Dr. Jekyll was both good and evil--he was by no means perfect, and it was the desire to suppress the evil part that drove him to create the potion that transformed him. Rather than suppress the evil and thereby make him good, it only gave life to the evil (and while the evil part was awake, the good-and-evil part of Jekyll was suppressed). The fact that he didn't split into a perfect side to complement the evil side was one of his main sources of anguish, and while it may be easy to read into that that humans really are inherently evil, another way to read the story is to say that there's no magic potion that will make people inherently good. Morality has to be taught and goodness must be practised; there's no circumventing the work.
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- totm mar 2024
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Hmm. *Pulls out the wit sharpener* I've been thinking about how to reply to this for a solid three weeks and I will say to you right now that it has been difficult to find the right words--admittedly, this is not so much because they don't exist but rather because it wouldn't do to cross swords with a moderator and violate 2.2(b) in the process. Discussions of human nature of themselves (as contrasted against discussions through the lens of the Kerbfleet story) may well come too close to being ideological in nature; I will endeavour to be as careful as possible to avoid falling on the wrong side of the line, first because I haven't received any warnings yet and, as I treasure my meagre offering of a reputation, would prefer to keep it that way, and second because if the opinion you gave is truly what you believe, then we disagree so deeply that I fear there can be no conciliation. Nevertheless, if that Philmont patch in your signature means what I think it does, we do share a lot of the same values, including courtesy, so if it seems to you that I am attempting to particularly ruthlessly eviscerate your point, then please let me know and we can remove the discussion to another place, or drop it altogether. Additionally, I began what I thought would be a quick retort and it turned into a term paper, so I put the bulk of it in spoiler tags to spare the eyes of the uninterested. Point the first: Point the second: Point the third: Point the fourth: Point the fifth: If, given the chance, we would be like the Kerbulans, then I offer the final point that unlike them, you do not accept this, and even more unlike them, you recognise that that sort of behaviour is wrong. The Kerbulans don't know or don't care, which makes you morally superior--but that may well be more a burden than a blessing. The worst that I can possibly do to them is pity them ... but they would not understand why. P.S.: If that other picture in your signature means what I think it does, then you have my condolences about your dog.
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Oh! I was given to understand that you had a different payload for your Mun orbiter. My apologies.
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@Solis: At first glance, it looks as though you have too much booster or not enough payload. You said that you used this launcher for a Mun orbiter, but if you're only going for Kerbin orbit, it appears that you have about twice as much rocket as you need.
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Duna Mission: What's it take?
Zhetaan replied to grafdog1138's topic in KSP1 Gameplay Questions and Tutorials
Timing is important, but one you know the correct time, getting it is as trivial as hitting the time warp button: obviously, you have to know when to stop the warp, too, but there are enough tools for that and others have covered that far better here. An uncrewed Duna rover that stays there will be far different from a crewed land-and-return, but if you've landed on the Mun (and returned) and you want a dead-simple Duna mission, take your existing Mun lander, add parachutes and a heat shield, and give it a bigger transfer stage. About one thousand metres per second more delta-V should do it. Just by glancing at the map, I can tell you that Duna requires about 1500 m/s more than the Mun for a one-way trip, but because you can aerobrake both going to Duna and coming to Kerbin, you don't really need to take that much. Depending on your configuration, you may need to get more powerful engines, but Duna's gravity is only twice the Mun's and most Mun landers have better than 2 thrust-to-weight (respective to Mun gravity; that won't even tip over on Kerbin), so unless you're right at the edge of that value, you probably don't need to bother. You may also need to use engines to soften the landing; parachutes are nice but Duna's atmosphere almost isn't there; keep that in mind so you don't crash. It is interesting to note that (albeit only with very careful flying) the stock Kerbal X can get to (but not back from) Duna. You can use that for some ideas if you like, though I will warn you that the Kerbal X has some problems with it (all the stock craft do; part of the challenge is tweaking them so they work better). I'll grant that it will not be the prettiest of missions, but unless you're playing with a life support mod, you can stand to keep your Kerbals in a can. If you want to visit Duna, the best piece of advice I can give you is to build a rocket that is enough to do the job and just go. Don't let it get bogged down in development hell by trying to design the do-absolutely-everything Duna mission. For Kerbals, time is cheap. For Kerbals in Science Mode, so are rockets. You aren't planning on visiting Duna only once, are you? And if you mess something up, so what? Deal with it and make the mission succeed anyway--you'll have more fun that way. If that's not possible, then fix it and do it again; you'll still have more fun doing that than spending the next six months in the VAB. -
@Solis: If your flight path has you pointing a few degrees east and then forcibly turning your rocket to forty-five degrees at ten kilometres altitude, then you can get some more efficiency out of it by taking a smoother ascent. If possible, you can help yourself a lot by letting the rocket turn slightly but constantly so that you start a few degrees east (as you do) and then sweep through the angle so that you happen to be pointing at forty-five degrees at about ten kilometres altitude. By the time you reach thirty kilometres, you should be pointing almost horizontally. Those points are just rough thumb rules, though, so don't feel the need to go crazy over them, and a lot will depend on the rocket itself. If you design it correctly, the rocket can actually fly itself to orbit with nothing more than a little nudge at the beginning (to point it the first few degrees east) and a bit of throttle control (to keep your apoapsis the right distance ahead of you). That's a true gravity turn, and there are a few example craft scattered about the spacecraft exchange and tutorials to show you how to make a rocket that can do this--though you're honestly fairly close with what you have. One of the Scott Manley videos also mentions switching to map view occasionally and keeping your apoapsis roughly a minute ahead of you until you're almost circularised. This advice is still good and can help you see what you want the trajectory to do. Having it widen is a good thing because it means that you're raising your periapsis and making an orbit rather than a dive-bomb. One of the things to remember about orbits is that the key is horizontal velocity, not vertical velocity. The thing that keeps you in the sky is not going up but rather, in the words of XKCD, 'going sideways really fast'. When you start off you need to go up a little because you have to get off the ground, get out of the atmosphere, and fight gravity for long enough that you can build up enough horizontal velocity that you don't need to fight gravity any more, but in order to save fuel and effort, you also need to start tapering off the vertical component in favour of the horizontal one right away--which is what you do when you nudge it a few degrees east and sweep through the turn. When you get to landing on and returning from Mun and Minmus you'll find that you can take off and then turn nearly horizontally almost as soon as you leave the ground, so you're actually learning the more difficult ascent first, on Kerbin. Congratulations on making orbit--now you're halfway to anywhere. Have fun.
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I traveled to Eeloo's surface and back using 1 fuel tank
Zhetaan replied to JacobJHC's topic in KSP1 Mission Reports
*Stops the video* *Replays the video* *Replays again* Wow! I have a few questions: 1. What's the story behind that wing profile? You added some weird admixture of dihedral angle and I-don't-know-what for stability, obviously, but I would have expected a lot more flexure from that many wing parts. Autostrut, I assume? 2. 311+ years? I'm interested to know why you picked the transfer windows you did. I'll guess that the reason has to do with Eeloo's eccentricity having a more pronounced effect on the efficiency of certain transfer windows over others, but I'd like to know what you have to say on the subject. 3. I really liked your landing leg solution to take-off. I was wondering whether you were going to try to stand the thing up on the engine bell and just jetpack up and down, or do something else, but I wasn't certain whether your reaction wheel module had enough torque to move that thing around. What gave you the idea? 4. How was your final?