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  1. Hello! After seeing krafpy's really cool multiple gravity assist planner, I was inspired to remake my KSP Transfer Illustrator app using Typescript. The result is a much more responsive app with a much better user experience! Links: https://kerbal-transfer-illustrator.netlify.app Kerbal Transfer Illustrator Description: The basic idea for the Transfer Illustrator was to take alexmoon's Launch Window Planner and add a few useful features – interactive 3D visualizations of transfer trajectories, additional transfer options, the ability to enter fully customized parking orbits, and a way to optimize transfers for highly-accurate in-game use. I think (and hope!) that this combination of additional features could make the app useful for KSP beginners and veterans alike. The Flyby illustrator is modeled after the Multi-Flyby Maneuver Sequencer in KSPTOT. It's not exactly a direct port, since there are a few differences both with UI and under-the-hood calculations, but my intention was to make something similar that could be more easily accessed over the web. Note that unlike krafpy's MGA Planner, it does not consider deep space maneuvers between unpowered flybys, but instead makes use of powered flybys. For this reason, the Flyby Illustrator and MGA Planner might give vastly different solutions for any given sequence of flybys. The Flight Plan Viewer is sort of a browser version of the in-game maneuver node editor. With a starting orbit, you can create and edit maneuver nodes and see the changes to the resulting trajectory in real time. You can also copy and paste orbits, maneuvers, and flight plans from the Transfer and Flyby pages! The System Editor lets you load and edit custom solar systems. You can upload Kopernicus configuration files to load your planet pack of choice! Plans for this project: I've re-implemented most of the features from my Python app, but there are a few that are still left to take care of: reading craft orbits from KSP save files (done!) loading/creating non-stock KSP solar systems (done!) exporting downloadable HTML plots (instead, save/share plots by storing data in the URL!) more departure/arrival trajectory options (e.g. Oberth maneuvers) (done!) For the Flyby Illustrator: Add additional UI options (multi-rev transfers, bounds of transfer legs, etc) Implement some of the departure/arrival options from the Transfer Illustrator (done!) Add "refinement" of trajectories by minimizing errors at SoI changes (done!) For the Flight Planner: Add more options for plots (show apses, maneuver nodes, ascending/descending nodes) Add surface textures to planets Any comments, contributions, or ideas for new features are appreciated! The Kerbal Transfer Illustrator is licensed under the Creative Commons Zero v1.0 Universal license.
  2. Hello, in this challenge you are going to do a mission similar to that of Voyager 2. Voyager 2 was an interplanetary and interstellar mission and passed through four planets of the solar system (Jupiter, Saturn, Uranus and Neptune) taking advantage of the positions of Jupiter and Saturn made the famous 'gravitational assistance' where Jupiter and Saturn would propel the ship to reach Uranus and Neptune and after leaving the gravitational pull of the last planet it would become an interstellar-type mission. This challenge is going to be more difficult since you will have to go through all the planets of the kerbol system(flying over) (except Eeloo) (it is not necessary to go through the moons but if you prefer you can go through them) and use the 'gravitational assistance' so that you do not spend a lot of fuel. You also have to return safely to Kerbin. The instructions are as follows: You must arm your interplanetary satellite. The maximum height for the satellite is 30 m You must arm your rocket and take it off Go through all the planets of the kerbol system (except Eeloo) using the 'gravity assist' Return safely to Kerbin Post in this post video or screenshots The rules are as follows. Visual mods allowed The use of mods that guide the ship to the destination such as (MechJeb 2 and MechJeb) is not allowed The use of the cheat menu is not allowed, if it were used they would be disqualified Refills are not allowed Greetings from Mexico
  3. I've been having trouble rapping my head around slingshot maneuvers. Enter Sphere of Influence (SoI) and exit SoI with changed velocity. It basically breaks down to four maneuvers. A and B are from a higher (faster) orbit, C and D are from a lower (slower) orbit. A and C are leading the object, B and D are trailing. There are some hints in https://wiki.kerbalspaceprogram.com/wiki/Tutorial:_Gravity_Assist It shows C and D. but what about A and B? Which ones will increase my exit velocity? C Which ones will decrease my exit velocity? D
  4. Hello ! I released an online tool that allows for automatic planning of interplanetary trajectories with multiple gravity assists. https://krafpy.github.io/KSP-MGA-Planner/ The tool provides an interactive 3D replica of KSP's solar system where you can zoom on planets and moons. It also provides a time selector to see the KSP's system configuration at a specific date. The trajectory calculator works in two steps: Generation of a planteray sequence : configure the origin and destination body, and constraints on the trajectory (maximum number of swing-bys...). The sequence generation calculates a set of possible sequences that respect the constraints you've specified. Trajectory optimization : once you've selected a sequence, you specify an earliest and latest departure date, and a parking orbit radius around the departure body. The tool will then run an optimization process to calculate a possible optimal trajectory with the given sequence and departure conditions. The details of the nomenclature and each settings is detailed in the "How to use" section. The calculated trajectory will be displayed in the solar system view: interplanetary orbit arcs as well as flyby orbits of each planet encountered. The date and ΔV along each axes of each maneuver are displayed. The trajectory can be vizualised step by step, and you can click on the date of each maneuver to set the system view to that date. Important notes and current issues : Despite the precision of the maneuvers details, it is very unlikely that following them will give the exact same trajectory in game. They do however result in a similar trajectory to the one calculated by the tool, and most of the time only some fine tunings are needed at each maneuver. There is no guarantee that the calculated trajectory is the best one. Since multiple gravity assists problems can only be solved using iterative optimization algorithm (here it's a differential evolution algorithm which is implemented), the result only approximates the best solution. It is totally possible that a better trajectory than the one calculated exists. A calculated trajectory may be unfeasible (more likely because of unfeasible flybys) in game due to the implementation not (yet) considering some parts of KSP's physics. A calculated trajectory may be complete non sense and absurd because of constraints implemented in the optimization process (this is very likely to occur when you look for trajectory between moons like in the Jool's system). These problems may be solved in the future. I hope this tool may be useful and I'm open to any feedback. Thanks !
  5. Wayfinder https://github.com/Muetdhiver-lab/Wayfinder Wayfinder is a python based Multiple Gravity Assist search tool for KSP, including support for the JNSQ planet pack. It allows for efficient search of gravity assist sequences using state of the art tools using pykep/pygmo packages from ESA. At the moment it's a set of python scripts with no GUI. Requires python 3.6 or 3.7 How does it work : Wayfinder uses a job batch system with the results of said jobs saved in an xslx format for storage and readability. Jobs can be added with the desired parameters (fly-by sequence, insertion type, search space bining, optimizsation level and so on). Once added, jobs can be run in batches, and results will be saved. Once results are saved, the results can be searched and accessed with a few utilites as : - finding the best result in a given set (sequence + launch dates) - display several sequences for comparison in terms of DV cost and Time of flight. - compare different sequences in a DV cost vs launch date line plot - display a job result as a flight plan in a text format References and thanks: This work would not have been possible without - pykep : https://esa.github.io/pykep/ - pygmo : https://esa.github.io/pygmo2/ - transfer planer for JNSQ : https://github.com/LouisB3/ksp-lwp-jnsq - the original transfer planer : https://github.com/alexmoon/ksp Special thanks to ESA to make those package available to the public, it's awesome. An other big thank you to the Jool5 Caveman Challenge , as it kickstarted the whole project.
  6. How do I plan a gravity assist using Kerbin similarly to how Juno used Earth to get to Jupiter?
  7. I planned a jool transfer node and can't find a encounter with tylo that slowed me into orbit without spending ridiculous amount of dv , does anyone know how to do it?(I'm going to laythe)
  8. This idea came to me while doing a challenge from discord, which was to launch 5 different sattelites to 5 different celestial bodies, where of 2 of them are different planets, in one launch. So of course, I said to myself, lets launch sats to every single planet and moons, but I taught too : if this was possible in one ejection burn from LKO...., and it is !! But it was kinda a headache haha Because of the sick flybies, and launch windows. As this is quite a long mission report, I'll split it in multiple posts, to avoid having a 47 km long one, but for those who wants, here is already the complete mission, with minimum set of mandatory pics (was for the challenge submission) : https://imgur.com/a/ogUlZKJ So here's the rocket, pretty simple: And the upper/transfer stage, with sats stacked on top of it The plan is to launch all this stuff to Eve, and when needed, release some Sats along the way, so they can follow their own path to their respective destination. the mission uses the following general path: K - E - K - K - Jool (same as Galileo) for Eve sats, obviously, only K - Eve. for Duna sats: K - E - Duna. for Moho: K - E - E - Moho. (Same as Messenger, but without the multiple Moho flybies, unuseful in my case) for Dres: K -E - K - Dres for jools sats K - E - K - K - Jool. And for Eeloo, K - E - K - K - J - Eeloo (with insertion in Jool orbit to wait for the Jool-Eeloo window) Next post, I'll cover the mission from launch to Eve arrival
  9. I'm trying to plan a mission to Moho. While I have MechJeb's Delta-V gauge to tell me if I can or cannot fly directly to Moho - fleet construction and organization is another problem - it does not tell me if I have enough Delta-V to do an Eve Gravity Assist to Moho. Here's the story. While planning transfer orbits for my Eve Fleet two months ago, I saw that the planned maneuver would have taken me in an escape trajectory out of Eve and into a somewhat low circular orbit around Kerbol - I forgot the specifics of the orbit, but it would have enabled me to put the crafts in some designated path for a contract. Now it got me thinking "Hey, maybe I can do that for a trip to Moho." If that's the case, here's my plan for a Eve gravity assist to Moho: Wait until the next Kerbin->Eve transfer window to escape Kerbin's sphere of influence (I have Kerbal Alarm Clock) As soon as I reach Eve's SOI, set my periapsis to 100-125 km and (possibly, it's been months since I was last at Eve) get in an escape trajectory out of Eve. Low periapsis requires less delta-V. Anything lower than 90 km will be dangerous (atmospheric burn-up, aerobraking messing up my escape trajectory, etc.) After leaving Eve's SOI (and in solar orbit), set up a Hohmann Transfer to Moho. On one hand, I get to do a really cool physics-based maneuver and (possibly) save delta-V (I don't say "fuel" since it's not the only factor used in MechJeb's Delta-V gauge) on my way to Moho. On the other hand, here are some numbers that may convince me that flying directly to Moho is just as good as using an Eve gravity assist. DIRECT FLIGHT LKO to Moho's Surface = 5490 m/s LKO to Low Moho Orbit = 4530 m/s EVE GRAVITY ASSIST TO SURFACE LKO to Eve Intercept = 1140 m/s Eve Intercept to Moho's Surface = 4350 m/s 1140+4350 = 5490 m/s TO LOW MOHO ORBIT LKO to Eve Intercept = 1140 m/s Eve Intercept to Low Moho Orbit = 3390 m/s 1140+3390 = 4530 m/s NO DIFFERENCE, IS THERE What do you think I should do to save Delta-V? Should I just stick with direct flights to Moho, or do you recommend I use the Eve Gravity Assist? If the direct flight is the best bet, fine. If the Eve assist is the best bet, then: How do I time it right to have the most efficient flight? Remember: I have Kerbal Alarm Clock. Any instructions for such a flight, or does my plan sound solid? Either way, off to the drawing board (I mean V.A.B.) for me. Your input is greatly appreciated. Thank you.
  10. So I am trying to get to duna with as little delta v usage as possible. Is there an efficiënt and doable way to use gravity assists to get to duna? I know of the oberth effect (sorry if I misspelled it). I just need to know how i can do an efficiënt gravity assist to duna. thx Edit: thanks for the comments so far. But to clarify, I do not want to refuel. An idea: would it in theory be possible to get myself in a 10% slower orbit than kerbin and then use a kerbin gravity assist. And would this even be feasable .
  11. Hello! I’ve been playing KSP for a while now and have become quite confident in my abilities. Although, I’m still having trouble with gravity assists. Is there an equation of some sort that I can use to calculate my speed after the slingshot/brake? Ex. Before assist craft is going x m/s, after the assist the craft is going y m/s I also would like to know if there is an equation I can use that will tell me the orbital velocity at a certain altitude above a body. Ex. At h meters with d degrees of inclination, the craft must be going x m/s to maintain a circular orbit If you have any other useful equations that would be nice, thanks!
  12. or does i can do this with mechjeb? How i can use Duna to reach Jool?
  13. I'm planing a manned Jool mission for my career save. The focus will be on extracting as much sweet, sweet science as possible from the Jool system before returning home to Kerbin. I'm going to use a NERV powered main mothership with 3 daughter landers to cover all the moons. (The Tylo lander will be an unmanned one-way trip!) Since this will be my first visit to Jool, I'm not sure what to expect for dV requirements after I capture into the Jool SOI. For a conservative estimate, I could simply add up all the numbers from the KSP delta-V map to get intercepts with each moon including the plane change amounts. This assumes (1) that the parent body will be Jool every time (2) no gravity assists from the other moons and (3) no daughter vehicles. With this in mind, do people have a ballpark number for the delta-v requirements to encounter all Joolian moons? I'm looking for rough estimates as a gut-check for my planning purposes, preferably from those who have done similar missions. I should also mention that I'm not planning to do any resource extraction, but I might need to if the dV requirements are too high.
  14. So I was watching this car jump from Minmus and noticed that a pass in front of the Mun tightened the resulting orbit considerably. Then I send my Iktomi explorer to Duna, and managed to pass in front of Ike, or rather, I crossed Ike's orbit just ahead of it. The insertion resulted in a wildly elliptical orbit, but it only cost me about 280 m/s. Then I take a look at what I can do out at the new apoapsis, and found that passing in front of Ike again would tighten the resulting orbit a lot, with the new apoapsis matching Ike's altitude, and only for a cost of 5 to 10 m/s. I imagine I could then tighten the orbit further for only a few m/s more at Duna periapsis, but didn't get a chance to investigate that yet. I want to understand what I'm seeing. I've read about and watched a lot of gravity assist examples on YouTube, but that car jump video had a very clear and beneficial example that I was then able to replicate. I remember that the assists are really directional changes at the body you're doing the assist at, but the new direction would instead represent some delta-v difference relevant to the parent body. But I'm wondering if a comparably simple rule would help me, something like, "pass ahead of a moon to slow down, pass behind it to speed up." At least in the two dimensions the typical orbital plane is in. --
  15. as the title says, it would be really nice if we could have a helper with gravity assists, like KER (is that going to be updated for 1.2? if ever?) but for gravity assists, so you could do gravity assists and missions like voyager, so you didn't have to have that much Delta-V on your rocket, so you can have more for the mission and moving around to adjust your orbit so you could make a mission like Cassini, resulting in more science, and more places you said you went to
  16. With the current excitement around the Juno mission approaching Jupiter after its earth-gravity-assist journey there'll be a lot of people playing around in KSP with similar goals. One thing that always holds me back in my interplanetary craft design is an efficient transfer as I always feel it is something akin to blind luck whether a planned assist will actually be useful or not since it is very difficult to set-up with options we have. Before launch we can use an orbital satellite say to set-up a practice node, and we can even edit the set-up files to show a couple more SOI changes in the patched conics but how do we set-up an encounter with Kerbin from within the Kerbin SOI? For reference this is the Juno gravity assist & an awesome video filmed from Juno of the earth fly-by Two years after launching and heading out beyond the orbit of Mars Juno returns to encounter earth again giving it the extra Kinetic Energy required to reach Jupiter. I know that there are a lot of complexities in achieving this, and KSP is just a game after-all, but so much has already been achieved with the 'Map' screen in making previously impossible concepts easily visualized and achievable that I wonder if there is some way I don't know. I've seen some videos of people setting up elaborate gravity assists that take 10's of years and minimal burns using precise node and Mechjeb ... but what can we do in stock (or near-stock)? Are there any tricks I don't know about? Improbable 34 stage wobbling skyscraper rockets screaming their way obnoxiously through atmosphere are fun and all ... but a trim efficient design can be much more satisfying.
  17. Hi everyone. This isn't a first for me. I tend to sling mission together with little regard for tolerances, especially when I am headed somewhere for the first time. So my situation is this: Orbiting Dres (first time visiting Dres yay!) with about 1067m/s Delta V left in the tanks and a requirement to Kerbin from Dres of around 1.3 km/s. I'm a little short as they say! The mission has gone perfectly up to now with a successful landing, and planned canyon skydive being completed, as well as a rove. I don't really want to get out and push as while possible, I did that the first time I went to Moho and want to try something different. I'm thinking Gravity assist would be the best way. I can get to Jool for around 700m/s by the looks of it so what do I do from there? Do I swing round Tylo (I've heard you can get a free ride home from there under the right circumstances) or has someone got a better solution to get me home within the 1km/s budget? Answers muchly muchly appreciated - I've never really got into Gravity assists so I'm a little out of my depth! EDIT: @Zhetaan wow that's some superb information there so thanks for pretty much dropping an education on my sorry mission to Dres! I will explore this in depth this weekend and report back for you. @PLAD thanks also for your input SM
  18. Hello! I'm trying to get a gravity assist to get into Jool orbit. I've never done this before, and I'd be happy to hear any tips! Here's what it looks like: These are my primary questions: How can I see whether I will be in orbit after I've exited Tylo's SOI, before I've entered it? How can I figure out where I need to enter Tylo's SOI, and at what angle, to be captured into orbit? I can easily provide more info if it's needed. Thanks a lot!
  19. The challenge: Once in low-Kerbin orbit and you've matched planes with Minmus, position a maneuver-node to allow you, with only one burn, to put your spacecraft on a free-return trajectory around minmus, BUT! also get an encounter with the Mün between escaping from Minmus and Kerbin periapsis. Bonus points if you can have the Mün encounter slingshot you in a way that allows even more gravitational assist maneuvers. Basically, start in low Kerbin orbit matched with Minmus' orbital plane. From that plane-matched low-Kerbin orbit, perform ONE engine-burn with as many gravitational encounters/escapes as possible without any extra engine-burns.
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