Jump to content


  • Posts

  • Joined

  • Last visited


4,973 Excellent


Profile Information

  • About me
    Talks To Boosters

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. It sounds like rocket construction is an area in which you can improve further. You'd be surprised just how much proper construction matters. A launch vehicle of five hundred tons in mass should get you really, really far if you built it well. I bet I could get a direct Hohmann transfer to a low solar periapsis in less mass than that, no need for a bi-elliptic one. If you're encountering a case where adding more fuel to your rocket is no longer improving its dV, you are most likely adding that fuel to an already overloaded stage, thereby causing other stages to get choked by the added mass. The way rockets work is that everything you add on top affects everything that exists below. This may sound daunting - that's like, an unlimited number of variables to take into account! Good news though - it's much easier than it sounds. Because the way the math works out, there's only one single number that matters for each individual stage, and you can in fact eyeball it most of the time and it'll be fine, so long as you avoid going really far off track. Doing the math just helps you learn how to eyeball it. I've written about it here before. Apologies, it's kind of a wall of text. I have a regrettable tendency towards those. Trust me though, it'll be worth your time Note that this is very inefficient, due to something called the Oberth effect. It's a particularly arcane bit of orbital mechanics, and you had no way of knowing this beyond figuring it out through trial and error, so don't be hard on yourself over it This is what the forum is for. The way it works, in simplified terms, is that spending fuel is more efficient the deeper down you are in a gravity well. It's not exactly that, but that's what it boils down to in practice in KSP. What you have been doing is spending a small amount of fuel to get out of Kerbin's gravity well, then spending a lot of fuel to aim at your actual destination while you are not anywhere near a gravity well. Thus you spent more fuel than you needed to. What you should have been doing instead is spending all your fuel deep in Kerbin's gravity well - in other words, making the full transfer burn in low Kerbin orbit. Counterintuitively, the same amount of fuel - indeed, the same amount of dV - would give you a noticeably deeper Sun periapsis then. Or, well, you can follow Zheetan's suggestion and do a bi-elliptic transfer. But even then, you'd ideally do the full transfer burn to your high solar apoapsis directly from low Kerbin orbit. Escaping Kerbin before even plotting your transfer is always the least efficient method. But how do you get from this tiny circle around Kerbin to your destination in solar orbit? Well, imagine Kerbin wasn't there. Imagine if it was just your spacecraft in a solar orbit that happens to be identical to Kerbin's solar orbit. What would you do to lower your periapsis towards the sun? Burn retrograde to your solar orbit, of course. And if you wanted to get out to Eeloo? Burn prograde, of course. So that's what you do, except that you must do it while circling Kerbin. You are in a low orbit around the planet, but your goal is still to make a burn in the correct direction relative to Kerbin's solar orbit. For example, if you want to go closer to the sun, you want to make a burn on Kerbin's sunlit side, so you are ejected from Kerbin's SOI "backwards". In other words, you make a prograde burn (relative to your low Kerbin orbit) that ejects you retrograde (relative to Kerbin's solar orbit). And going out to Eeloo is the same, just on Kerbin's night side. You make a prograde burn (relative to your low Kerbin orbit) that ejects you prograde (relative to Kerbin's solar orbit). In this way, the burn to escape Kerbin's sphere of influence is at the same time a burn in the right direction relative to solar orbit, so you can just keep burning in the same direction to lower your solar periapsis (or raise your solar apoapsis) despite still being just a few kilometers above Kerbin's atmosphere. Of course, depending on the amount of dV you must spend and the acceleration your engines provide, making a very large burn in low Kerbin orbit can be very tricky. Because the orbit is so strongly curved, and you traverse a significant portion of the circle in just a few minutes, burns you make there grow less and less efficient the longer they get. If you burn at the maneuver node, you'll burn off-prograde for most of the time, whereas if you follow the prograde marker, you'll not burn in the right direction for most of the time. Rule of the thumb is that if your burn is longer than six minutes (three before the node and three after), you're starting to get inefficient. You can get around this by splitting the burn. For example, make one burn that raises your Kerbin apoapsis to around where the orbit of the Mun is. (Take care not to actually encounter the Mun, you don't want that here.) Loop around once, and as you come back towards your Kerbin periapsis, make a new maneuver node there and start a new burn in the same direction as the first one - basically continuing what you started. Once you have an escape trajectory out of Kerbin's SOI, you can keep burning until you have achieved your desired solar orbit destination.
  2. Does it specifically say the word "dock" anywhere in the contract? If not, then all you need to do is get them within physics load distance of each other - in other words, within roughly two kilometers. Note that the two spacecraft performing the rendezvous must be from different launches. You cannot put two probes on the same rocket, throw them at the Mun with slightly different trajectories to separate them, and later have them meet up again once there. That won't complete the contract. Also check the contract (and the app in the toolbar) carefully for mentions of requiring newly-launched spacecraft. This clause is common in satellite contracts, for example, and I'm not sure if it also exists for the rendezvous contract. If you also happen to have a "build a space station in orbit of the Mun" contract, you can do both at the same time. One launch to put the station there, and another launch to either just visit it, or to add whichever missing parts didn't fit on the first launch due to bulk or weight issues. The visiting spacecraft can also be a lander looking to touch down on the surface (or coming back from it).
  3. Try upgrading your tracking station. It improves the display of orbit lines, and additionally, unlocks extra data displays in one of the menus on the bottom left in flight mode.
  4. Nah, it's working fine. It is, in fact, working perfectly fine. Too perfectly, one might say. I've previously written about this here:
  5. First thing to check: that node towards Duna, does it ask you to burn right now? Or in XYZ days? Due to Kerbin's circular orbit around the sun, the direction the node sends you in changes as time passes. The direction doesn't need to be correct hundreds of days ahead of the transfer window; it only needs to be correct at the time you need to execute the transfer burn. The tool should place your node in the correct position for the alignment to match properly at the time of the burn. Second thing to check: are you playing via Steam? If so, let it do a file verification on the game. If not, completely uninstall everything, download the game fresh, and reinstall in a clean folder. Then, see if your alarm clock issue perists. If yes, please give us a number of steps which for you lead to to this issue reoccuring every time, which anyone can do for themselves. As in: start new sandbox save, spawn Kerbal X, launch into orbit, etc, etc. If it only happens in one specific savegame, provide that savegame for download, and explain whether it is a new save you started in 1.12, or an older save you've carried forward.
  6. I have never seen anything like it. Can you take a screenshot or video of the effect?
  7. For the limitations of the current implementation, see the link below. Meanwhile, if you can actually produce a situation in which the transfer tool creates a node that literally does not work (like not even leaving the SOI), then please try and see if you can find a way to consistently reproduce it. Like, a series of steps going "load this save file, go fly craft XYZ, use tool to create node to destination ABC". If you can find such a reliable reproduction method in a save completely without mods, please create a bug report with it at https://bugs.kerbalspaceprogram.com and then link to it here. I'll make sure it gets seen. Provide all the information you can, such as a save file for download, and precise instructions on what to do with it.
  8. See here: Same effect causes the transfer tool to tell you to wait multiple days for a simple Mun transfer.
  9. The Advanced Grabbing Unit (also called "the klaw") is a part that can latch onto another ship and establish a docking connection without the need for a docking port on the target ship. Though, note, I'm not sure if certain difficulty settings might not interfere with fuel transfer across the klaw. Even in that case, though, you can still use the engines on the ship with the klaw to pull your Eve return craft's orbit down to intersect with the atmosphere. After that, it's just a question of aerobraking until you reenter.
  10. @Termopsis Is that in an existing save, or did you start a new one? Also, did you mean update 1.12? You wrote 1.11, but that was the previous one. The one that just launched (on PC, anyway) is 1.12.
  11. The alarm clock app gives you the time of the start of the transfer window. Not sure how the size of the window is defined, but it's a period of multiple days. The best possible second to launch will be different than the time the alarm gives you, because the alarm only tells you when the window starts, and the best possible time is somewhere in that window. In practical application, for all bodies other than Moho it doesn't really matter if you're a day or two off of 'perfect'. You'll still get an encounter just fine. The transfer app, meanwhile, searches for the mathematically perfect solution to create a maneuver node. This means that it often decides to give you a node for a transfer window far into the future, because that future transfer would be mathematically better than the best the current window has to give you. This obviously doesn't help if you want a transfer for this window. This has already been raised as feedback during prerelease testing and acknowledged; but sometimes, a week or two before release is just not enough time to research and implement a fix and then run it through the entire proper test-QA-release process. The tool will likely be improved in a future patch. Probably. I'm not a dev, I'm just a volunteer
  12. The transfer app requires building upgrades. After all, you already need to upgrade a building to even make a maneuver node by hand. It would be silly to give you a tool that would make nodes for you even before that, right? The fireworks launchers are parts, and like all parts in career mode, are somewhere in the tech tree. If they are not in the tech tree, that would be a bug.
  13. No, that's not quite it. You wait until you see the Mun rise, and then you burn straight prograde. Not at the horizon/the Mun. In general, never burn directly at the destination you want to go - that's not how orbital mechanics works Only when you're trying to meet up with another spacecraft and have managed to get within 10 kilometers of it. Then, and only then, you can go straight towards it. When you look for the Mun rising, feel free to start burning immediately as soon as you see it. The perfect moment would actually be slightly before it becomes visible, but of course you can't see that moment. So you simply wait for it to peek over. EDIT: And if you still want to practice with maneuver nodes as well - here's a post I once made with a step-by-step guide about how to get a good Mun maneuver node. Not sure if it's what you're looking for, but I did include a video that shows the process in practice.
  14. I don't know. Can you? In all seriousness, the answer is "yes, if you have a docking port, and the skill to perform a rendezvous and docking". It's a perfectly valid strategy, and people have built entire motherships out of 10+ individual launches in orbit. The main difficulty is the inherent wobbliness of docking connections. If you want to move a 700 ton vessel, you have to bring either a lot of thrust or a lot of patience, and if you pick the thrust option, that poor docking port is going to struggle. So my recommendation is: bring an engineer and an inventory full of struts. Once docked, the two vessels are considered a single spacecraft, which means you can strut from one to the other in EVA Construction Mode to stiffen it up. The struts will later automatically disconnect upon undocking.
  15. So long as it flies as a rocket (as in, thrust dominates all other forces), a vessel shouldn't care much about where its center of lift is. It's the center of aerodynamic pressure that must be behind the center of mass for the vessel to be stable. CoP and CoL are not the same thing, and the little blue ball in the editor only ever shows CoL. You can pretty much ignore it 100% of the time in the VAB, unless you're specifically designing something that is meant to do aerodynamic flying at some point. In which case you only pay attention to it for that specific stage. As there's no way to see CoP in the editor, you have to eyeball the stability of your rocket. OP's rocket did not strike me as overly unstable from the image, and since both he and others have successfully flown it into orbit, that first impression appears to hold out.
  • Create New...