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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. July 2022 Update: How to add solar systems The tool can now support different solar systems from mods. Follow these steps if you want to use the tool on a solar system that is not supported: Fork the project from its github repository (https://github.com/Krafpy/KSP-MGA-Planner) and create a new branch for your solar system. Create a new folder in the `data` folder where the solar system data will be stored (e.g. data/some-system). Copy the `config.yml` and `bodies.yml` files from the `data/stock` to the folder you just created and edit them with your solar system data. `config.yml` stores the global configurations of the tool. These parameters must be changed depending on the properties of the solar system (e.g. duration of a day, camera clip distances for large solar systems...). `bodies.yml` stores the description of each bodies in the solar system. Follow rigorously the edit notes. If the solar system uses Kopernicus' .cfg files for configuration, you can directly convert them into a `bodie.yml` file on this page : https://krafpy.github.io/KSP-MGA-Planner/tools/cfg-to-yml/ Add an entry to the `data/systems.yml` file, following the template. Test the tool on your computer with your system. You simply need to run a HTTP sever on the repository folder (I use VSCode live server). Create a pull request to the github repository for me to merge it (only for mods, not personal solar systems). 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 !

Kerbal Transfer Illustrator Link: https://kerbal-transfer-illustrator.netlify.app Description: The Kerbal Transfer Illustrator is a set of mission planning tools inspired by alexmoon's Launch Window Planner, Arrowstar's KSPTOT, and krafpy's MGA Planner, among other things. It consists of 4 interconnected pages, which each make use of pretty, interactive 3D displays of the solar system: Transfer Illustrator: Generate porkchop plots and calculate trajectories for any starting and ending orbits in a solar system Optimize trajectories for accurate in-game use Optionally use Oberth maneuvers for arrival and departure from celestial bodies Flyby Illustrator: Search for efficient multi-gravity-assist missions with powered flybys Optionally make use of deep space maneuvers between flybys (work in progress) Optimize trajectories for accurate in-game use (usually reasonably accurate, work in progress) Flight Planner: Visualize trajectories for multiple crafts Plan relay constellations by looking using the CommNet display Manually edit individual maneuver nodes and see real-time changes to the resulting trajectory Copy and paste flight plans from the Transfer and Flyby Illustrators System Editor: Tweak settings for individual planets, or make entirely new solar systems Load modded systems from Kopernicus configuration files Use custom systems in the other pages of the app Also note that orbits and crafts can be loaded from your KSP save files, and links can be generated from each page to save/share your flight plans! Modded systems that are already built in to the app include: Outer Planets Mod JNSQ Galileo Planet Pack Real Solar System KSRSS 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.

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.

Hello everyone! The capstone of stock KSP missions is the “grand tour” - landing on every planet and moon in the Kerbol system. (You can technically land on Jool but that’s not traditionally counted). A single launch grand tour is a feat of precision engineering, careful mission planning, and the dedication to actually fly fifteen landings and return safely. The first mission I'm really proud of was a grand tour mission (which was also my first ever Eve return), and I posted an album of it on this forum. The mothership looked something like this: And this was the entire craft: Like most grand tours, this is a very large rocket, and I completed this mission mostly through pure brute force. I did use some gravity assists, but this rocket absolutely conforms to the "More Boosters" philosophy more than anything. This was done in October of 2020, shortly after I started playing the game, and you can see that in the distinct lack of optimized craft design. But that was two years ago, and since then I've gotten much better at craft optimization, gravity assists, piloting, and the game in general. Probably the best example of this was the Eve lander of this early mission, which looked like this: It’s a pretty large lander and way overbuilt for Eve, but it got the job done. And then a while ago I did a 7.5 ton Eve mission, which I later cut down to just under 7 tons. This is still the record for lowest mass kerballed Eve return without abusing “magic wing” type glitches, even without ISRU. It gave me an idea - since this Eve lander was so much smaller than my first one, could I make a grand tour mission, but this time putting a special focus on minimizing mass? I first started thinking about a minimalist grand tour in February of 2022, but exams prevented me from doing much more. I revisited the concept in June, and managed to cobble together something vaguely resembling a craft - but I was occupied with graduating college, and it never flew. Here’s a picture of it anyway - it is similar in concept to my final design: This was only part of the final craft, and was already projected to be much smaller than my previous grand tour - at the time I estimated a final mass of around 20 tons. As far as I’m aware, this would still be the lowest mass grand tour ever, as the lightest I know of is Brad Whistance’s 25 ton craft which made heavy use of ISRU. But this was unsatisfying - I was still leaving a lot of mass on the table. My original grand tour mission used Mammoth engines on the first stage. I wanted to have the mass of my entire craft be less than the fifteen tons of a single one of those engines. About a month ago, I finalized the design of the craft: 14.45 tons - well within my mass goal of 15 tons. As you’ll see, I could have pushed this even lower, but I chose not to because I had already met my goal. A breakdown of the craft design is below. I made a video showcasing this mission, also. I've put my comments on it (time stamped) in a spoiler box below.

(This was first posted on the Space Exploration StackExchange and the AskScienceDiscussion subreddit first, but I want more input, so I'm posting here as well. As forewarning, the most integral details of this question are bolded.) For context, I have been writing an alternate history involving the accelerated development of spaceflight technology for over 5 years now (one with quite different assumptions from other examples of the subgenre), and one of its long-standing elements has been a wildly-ambitious space probe that would be sent on a Solar System Circumnavigation through a Grander Tour. What does this mean? Well, here are the mission objectives: The main spacecraft body (which I will obfuscatorily name “the Spacecraft”) must fly by every planet (1930–2006) in the Solar System save Pluto. At least a subprobe (“Subprobe A”) must fly by Pluto. Double points if it manages to do so while flying by all 8 other planets. A sample, no matter how miniscule (probably micrometeorites or ring particles), must be returned to Earth by a subprobe or sub-subprobe (“Subprobe B”) after flying by all 8 2006– planets. The course correction to do so may involve as much as an orbital-scale (~9000 m/s) multi-stage solid rocket together with aerobreaking and/or a brutal gravity assist. Double points if it is on or launched from Subprobe A. Triple points if it is on or launched from Subprobe A after the Pluto flyby. Each flyby in the Outer Solar System should preferably be at least 1 synodic period before that of the real-life Grand Tour users the Voyagers in order to prepare for the arrival of a vaguely equivalent program. The base of the spacecraft’s conception was that it would be launched around the time of or before the first outer planets and interstellar probes in real life (Pioneer 10/11) to make time for it to engage on a more proper Grand Tour trajectory. This was reinforced by the fact that said time range roughly overlaps with the 450th anniversary of an Earth circumnavigation expedition done by the crew of a certain navigator, who happens to be the namesake of a far less impressive real-life space mission. So, the rock-hard minimum and maximum are the 450th anniversary of the start of that navigator’s voyage (September 20th, 1969) and the launch of the latter Pioneer, Pioneer 11 (April 5th, 1973). However, it would ideally be launched before September 6th, 1972, exactly 450 years after what was left of that expedition returned, yet as close to that date as possible (i.e. within 1972) to allow as much advanced technology to be used in it as possible—the spacecraft would include developments like 8-bit microprocessors, helical-scan tape data storage, robotic arms, synthetic aperture RADAR, and possibly non-solid-state radioisotope generators. And yes, the first asking of this question was deliberately timed to match with the 50th anniversary of that date and the 45th anniversary of the launch of Voyager 1. (I’d have preferred it to be earlier, but ehh…) Also, the spacecraft’s original conception had it launched on a Saturn IB–Agena D (what I thought was the highest-capacity high-velocity non-Saturn V notional “drop-in” vehicle that could have been made at the time… ignoring that either a Saturn IB–Centaur or earlier Titan IIIE would have greater capacity and could probably be made with similar R&D), but as its size and capabilities grew, its proposed launch vehicle was progressively upgraded until it became the “Saturn 1E-SB”, which consists of 4 stages (more details on which could be provided if required), the last one, not considered integral to the launch vehicle’s identity, being the main course correction stage of the spacecraft. The first 3 stages would have the capability to put the 4th stage and ~5.5-ton spacecraft complex—~28.5 tons in total and ~6.75 tons dry mass—on a trans-Cytherean or potentially trans-Martian injection (up to 3650 m/s tested in KSP RSS RO using a penultimate version of the launch vehicle, probably ~3800 m/s), beginning its Grander Tour… A Saturn V could do so, too, and to be honest I now find justifying the existence of the Saturn 1E-SB somewhat difficult, so I may bite the bullet of switching away from a “Saturn one” platform. Now, how much ∆v would the course correction stage be capable of supplying? A measly… ~5500 m/s. And that’s with the subprobes still attached. So there is a very beefy, though not unlimited course-correction capacity. Now, orbital mechanics is a complex business, and I don’t know if it would even be possible to fulfill even the barest mission requirements given the ∆v budget within that launch window, let alone how it would be done. However, the existence of trajectory designs like this, a flyby of all 2006– planets launched in the same vague timeframe with a negligible course-correction budget, indicates its likely possibility. Note that the 5500 m/s and 5.5 tons payload is a maximum and minimum, respectively—the more optimized the trajectory can be made, the smaller the fuel mass of the course correction stage needs to be, allowing a greater scientific payload, so the more optimized the mission is, the better. And so, the question. Ideally, I’d like to have the specifics of this drilled down by April 5th, 2023 for some sense of timeliness. For more context, this is the encounter order as planned when the conception of this mission reached its modern form: Main spacecraft: Earth→Venus→Mercury→Venus→Mars→Jupiter→Saturn→Ouranos→Neptune→Interstellar Subprobe A: 〃→〃→〃→〃→〃→〃→Pluto→Interstellar Subprobe B: 〃→〃→〃→〃→〃→〃→〃→Ouranos→Neptune→Earth

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

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

How do I plan a gravity assist using Kerbin similarly to how Juno used Earth to get to Jupiter?

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)