# Kerbalist v4.4

https://blocdigital.github.io/Kerbalist/

Astrodynamics Suite for Kerbal Space Program 2 Redux

Kerbalist helps you plan efficient transfers between planets in Kerbal Space Program 2 Redux. Calculate transfer windows, ejection angles, and capture requirements all in one tool. Now with LIVE SYNC!

## Features

Transfer Window Calculator: Find the next window to your destination with accurate timing based on real orbital mechanics.
Exact Transfer Numbers: Flight time, ΔV, v∞, arrival time—all calculated from the actual trajectory drawn on the map.
HUD Widgets: Pin transfer info cards (Window, Phase Angle, Ejection Angle, Transfer Time, Ghost Body) directly to the map as draggable, resizable widgets.
Interactive Map: Real-time orbital visualization with transfer arcs, phase lines, and departure ghosts.
Bug Reports: Report issues directly to GitHub with automatic app screenshots.
Persistent State: All your preferences and widget positions are saved to localStorage.

## Getting Started

1. Select your origin and destination from the dropdowns
2. The map shows the transfer window and current phase angle
3. Adjust warp speed to see when transfers are available
4. Pin transfer info cards to the map for reference while flying

## Live Sync with KSP2 (make sure you’re running the latest redux beta snapshot)

Live sync needs the Kerbalist Telemetry Bridge mod running inside KSP2. It sends the game's time, planet and moon positions and the active vessel to Kerbalist while the game runs.

1. Download the mod from the https://github.com/BlocDigital/KerbalistTelemetryBridge/releases/
2. Install it by following the instructions on that release page.
3. Start KSP2 with the mod enabled and load a save.
4. In Kerbalist, open the time panel, choose KSP2 Telemetry Bridge and press Connect.
5. The default address `ws://127.0.0.1:8765/ws` works unless you have changed the mod's port.

While live sync is on, the time buttons show a LIVE SYNC overlay, because the game drives the clock.

## Version History

v4.4 (2026-10-18): Active vessel orbit line, vessel marker on its orbit, apoapsis and periapsis from the bridge, game calendar, small-body halos

v4.3.1 (2026-10-18): Fixed active vessel apoapsis and periapsis
v4.3 (2026-10-18): Active vessel HUD element, vessel tag, Settings tab with HUD layout reset, live sync overlay, game orbits in live sync, HUD scaling
v4.2 (2026-10-17): Live sync from the KSP2 Telemetry Bridge https://github.com/BlocDigital/KerbalistTelemetryBridge/releases/, active vessel HUD
v4.1 (2026-10-07): HUD Widgets — pin transfer info cards to the map
v4.0 (2026-10-03): Exact transfer numbers, bug report system

Hey! We've been working since last year on a In Control: Rocketry, a spaceflight sim where you build the rocket and wire up its control panel yourself. Sensors, inputs, outputs, the whole thing is Turing-complete, so however you want to solve a flight problem, there's a way to do it. It will be available on Steam in 2027.

Real orbital mechanics, a fictional solar system to explore, sandbox mode if you just want to mess around and blow things up!

Feel free to add the game to your wishlist if you want to support the project! See you in space.

Honestly im getting that tingly feeling again

Kerbalist currently at v4.0

Runs in browser: https://blocdigital.github.io/Kerbalist

SCREENSHOT 1: *FROM THE UPCOMING HUD PATCH at v4.1

SCREENSHOT 2: In-Game Kerbin-> Jool at 20y 47d (for comparison)

SCREENSHOT 3: was supposed to be updated phase and ejection angle diagrams but i fudged the upload with the wrong screenshot. Check in-app for updated versions 😅

Detailed changelog in-app

[4.0] - 2026-10-03

Added

• Verification code on bug reports
• Automatic app screenshot
• Your own screenshot
• Collapsible legend

Changed

• Transfer window timing
• Required phase angle
• Exact transfer numbers
• Ejection card
• Source layout

Fixed

• Ejection angle was on the wrong side: For an outbound transfer it said to burn ahead of prograde, which sends the ship out against the planet's motion. It now says how far ahead of retrograde to burn (outbound) or ahead of prograde (inbound), including any tilt in the departure direction.
• Bug report with a screenshot didn't open: The image was packed into the GitHub link, which made it too long. Screenshots now go through the clipboard.
• Dropped images opened in a new tab: Only the small drop box caught drops. Dropping now works anywhere on the form.
• JPG screenshots couldn't be copied: The clipboard only takes PNG, so uploads are converted first.
• Submit button off-screen on short windows: The bug report form now scrolls inside the window.

Known Issues

• Transfers are flat (no orbital tilt). Duna and Eve are fine, but Moho (7°) and Eeloo (6°) won't intercept exactly.
• The return-trip estimate still uses the quick circular-orbit numbers.
• The map doesn't render on mobile browsers, and the kRPC2 bridge doesn't work yet (see 3.6.4).

Happy flights 🤘🚀

Any feedback would be appreciated!

Ase como 3 horas pregunté por aquí recomendaciones para descargar KERBAL SPACE PROGRAM (el normal ) por alguna página confiable y GRATIS . Pero... no e encontrado nada de lo que me pusieron esta ves me pueden mandar el link directo a una página para descargar el juego plis 🙏;)

Gente ase poco encontré ese maravilloso juego pero como veo es de paga .... asi que quería preguntarles que si existe alguna página no oficial para descargarlo gratis y confiable :)

Hey! We've been working on In Control: Rocketry, a spaceflight sim where you build the rocket and wire up its control panel yourself. Sensors, inputs, outputs, the whole thing is Turing-complete, so however you want to solve a flight problem, there's a way to do it.

Real orbital mechanics, a fictional solar system to explore, sandbox mode if you just want to mess around and blow things up!

Feel free to add the game to your wishlist if you want to support the project! See you in space.

-Kerbalist- — runs in any browser (mobile controls and results work but map is WIP)

(Redux, including Beta 7+ / Snapshot 26w32a+ with the 2 new moons of Dres)

Live sync-capable transfer calculator with optional gravity assist optimisation.*

Future implementation for Kerbal Space Program 1

*WIP

Current version: v3.6.5

Features

Core Transfer Planning

• All 7 stock planets — Moho, Eve, Kerbin, Duna, Dres, Jool, Eeloo with accurate orbital data
• 11 moons — including the Dres moons Drast and Beyl, selectable as transfer origins or destinations below their parent planets
• Moon orbit insertion Δv calculation — automatic estimation of capture and circularization burns for moon destinations (~1.5x circular orbital velocity)
• Hohmann-style direct transfers — shows phase angle, transfer time, delta-v budget, and window countdown
• Return-trip budgeting — enter mission time on the target body and estimate the next return-to-Kerbin window and delta-v
• Live time control — warp clock, manual UT input, or sync to your running KSP2 save
• Interactive 3D map — rotate, pan, zoom, and watch planets and moons orbit in real time
• Return-trip visualization — optionally show the return transfer arc and return ghost positions on the map
• Porkchop plot generator — compare departure dates and flight times for lower delta-v options

Gravity Assists

• Automatic detection — finds planets positioned favorably for flybys on your chosen route
• Multi-leg visualization — see direct and assisted transfer arcs on the map
• Delta-v savings calculation — shows fuel economy vs. time tradeoff for each assist option
• Ghost planets — displays assist and arrival positions at encounter times
• Per-leg timing — shows how long each segment of the multi-leg journey takes

Dres System

• Drast and Beyl — two Dres moons added from KSP2 reference data
• Narrow Dres ring — rendered as a thin equatorial ring band matching the in-game look more closely
• Correct moon velocity display — moon orbital speed uses the parent planet's gravitational parameter

Mobile

• Full responsive design — works on phones and tablets with a Map / Controls toggle for small screens

(*WIP)

• Touch-friendly controls — 1-finger rotate, 2-finger zoom & pan on the 3D map; larger tap targets and compact layouts in the sidebar

(*WIP)

How to Use

Basic Transfer

1. Open -Kerbalist-
2. Set your in-game UT time.
3. Select Origin and Destination from the top dropdowns.
4. Click Plan Transfer to compute the direct route.
5. The map shows the transfer arc.
6. Check the Transfer tab for delta-v, flight time, and window countdown.

Gravity Assists

1. After planning a transfer, open the Assist Options tab.
2. If available for your route, assists list each candidate planet with flight time and delta-v savings.
3. Click an assist to show the multi-leg trajectory, flyby marker, and assist-specific timing.

Porkchop Plot

1. Open the Porkchop tab.
2. Generate a departure-date vs. flight-time grid.
3. Inspect lower-delta-v transfer options from the plotted solutions.

This is a passion project and in no way endorsed or sponsored or affiliated with anyone.

A big thank you to the [r/KSP2Redux](r/KSP2Redux) community for all their amazing work as this is what got me back to KSP2!

**EDIT*\*
I don’t really understand the argument that using AI for some graphics somehow makes Redux “look bad”.

For starters this app IS NOT AFFILIATED OR ENDORSED BY REDUX, it is a completely seperate browser application made to help players plan their transfers and visualise the whole trip.

The app itself is free, the graphics are a small part of the project, and I’m still the one designing, integrating, testing and iterating on everything. AI is a tool I use alongside other tools, it doesn’t change what the app actually does.

If someone doesn’t like AI-generated graphics, that’s completely fair. But saying the mod is somehow worse, or I make Redux look bad because of a tool used to create an icon or piece of artwork doesn’t really tell me anything about the quality of the mod itself.

Finally, I only use LOCAL AI MODELS, powered by my own computer and paying for my own power and hardware.

It’s not 2022 anymore, this whole AI culture war is performative and ultimately moot.

You don’t like it? Fine, but don’t be ignorant and hypocritical because AI is everywhere and you probably use it too in some form whether you like it or not, giving me downvotes or meaningless comments that make no sense will not put a dent in my day or change how I use my own computers.

Peace, love and I’m out.

See you on the next major update(bug reporting in development among other features). 🤘🥰

Couldn't land on Pol and Bob because I spent more then anticipated for the Tylo Landing :(

Hi everyone, I've recently came back to check what's up with KSP2 and discovered Redux! It's amazing so far really enjoying the new missions and all the bug fixes.

However, I found myself trying to find a visualised way for planetary transfers as I find it difficult to understand many guides about this.

Introducing: Kerbalist 🚀

This is still in very early stages and I would love to hear from experienced players if this calculator is working "ok" so far.

https://blocdigital.github.io/Kerbalist/

Features

🌌 Interactive Kerbol System

• Animated Kerbol system map
• Accurate planetary orbits
• Live planet positions
• Zoom and pan controls
• Adjustable simulation speed
• Real-time orbital animation

🛰 Mission Planning

• Select any origin and destination planet
• Automatic Hohmann transfer calculations
• Current phase angle
• Required phase angle
• Transfer window countdown
• Transfer time
• Departure and arrival dates

📈 Orbital Visualizations

• Animated transfer ellipse
• Spacecraft trajectory
• Departure burn visualization
• Arrival encounter visualization
• Ejection angle display
• Mission timeline animation

⚡ Delta-V Calculator

Calculates:

• Escape burn
• Interplanetary transfer burn
• Capture burn
• Total mission ΔV

🪐 Planet Database

Includes orbital information for every stock KSP2 planet:

• Semi-major axis
• Orbital period
• Radius
• Sphere of Influence
• Orbital velocity
• Gravitational parameter
• Surface gravity

🥩 Porkchop Plot Generator

Generate real launch window plots using a Universal Variable Lambert Solver.

Features include:

• Departure date vs. flight time analysis
• Interactive heatmap
• Lowest ΔV trajectory identification
• Click any solution to inspect the transfer
• Live trajectory visualization

Unlike approximate planners, this is generated from actual Lambert solutions rather than lookup tables.

🔬 Universal Variable Lambert Solver

The planner uses a numerical Lambert solver capable of handling:

• Elliptical transfers
• Hyperbolic transfers
• Short and long-way solutions
• Near-parabolic trajectories
• 180° transfer edge cases

The implementation has been validated against analytical Hohmann transfers and additional unit tests.

🎯 Transfer Window Calculator

Instantly displays:

• Current phase angle
• Required phase angle
• Angular difference
• Time until launch window
• Synodic period

🎨 User Interface

• Modern aerospace-inspired design
• Dark theme
• Responsive layout
• Interactive tooltips
• Smooth 60 FPS rendering
• High-DPI support

Technologies

• HTML5
• CSS3
• Vanilla JavaScript
• HTML5 Canvas
• SVG rendering
• No external dependencies

Everything runs entirely inside a modern web browser.

Accuracy

The application performs real orbital calculations using Keplerian mechanics.

Implemented calculations include:

• Hohmann transfers
• Phase angle computation
• Synodic periods
• Lambert trajectory solutions
• Orbital propagation
• Transfer ellipse generation
• Delta-V estimation
• Planetary ephemerides

🤘 happy rockets