I, Voyager: an Open-Source Software Planetarium

I, Voyager: an Open-Source Software Planetarium

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We are two weeks from launch!

I, Voyager is a free, open-source software planetarium designed for game and educational software development. It features the real, dynamic orbits of planets, moons and asteroids — with much more to come!

I built I, Voyager to be improved, modified and extended by the community. A big part of that is the open-source Godot Engine that runs it. I, Voyager uses Godot’s easy-to-learn GDScript (similar to Python) and can be extended using GDScript, C# or C++. Every line of code in I, Voyager and Godot is open for inspection and change. Godot provides the hard stuff (GUI elements, 3D renderer, etc.) and access to a friendly, knowledgeable and rapidly growing community.

I am releasing I, Voyager under the same permissive MIT License used by Godot permissive Apache Licence 2.0. What does that mean? Projects built with I, Voyager are owned by their creators. You can sell what you make. There are no royalties or fees, and license compliance is relatively simple.


My first program was a 2-body orbital system written in BASIC on a VIC-20. I’ve remade that program every ten years or so, each time with more detail and better tools. I didn’t particularly know what a “game engine” was two years ago, but I stumbled into Godot, downloaded it, started coding in late November, 2017 — by December I had TestCubes orbiting bigger TestCubes orbiting one really big TestCube. The rest is polish, — except for the name, which I struggled with for a long time. The starting point was this image. After more than a few working names I finally arrived at “I, Voyager.” It’s a play on Voyager 1 (the spacecraft that took that image) and in honor of the Voyager Program.


I, Voyager screen capture of Europa, Jupiter and Io.
I, Voyager screen capture of Europa, Jupiter and Io.
I, Voyager screen capture of the orbital paths of the moons of Jupiter
Orbital paths of the moons of Jupiter.
I, Voyager screen capture of asteroids. Main Belt asteroids and Trojans (orbiting 60° ahead of and 60° behind Jupiter) are prominent in this image.
Jupiter (♃) is the shepherd of our Solar System. Shown here are some ~200,00 asteroids; the vast majority are in the Main Belt (the ring inside Jupiter’s orbit) but quite a few are in the two Trojan groups (the “lobes”) orbiting roughly 60° ahead of and 60° behind Jupiter.
I, Voyager screen capture with user interface, showing Earth, Selection Panel, Info Panel and Navigation Panel.
We have some basic interface to move around and see things, including Wikipedia text for the selected object. Developers can extend, replace or remove user interface elements.

Join the community!

Please join our dedicated I, Voyager Forum! You can find our newsletter signup on the main site and downloads here (on Nov 9!). For developers, our repository home will be at github.com/ivoyager.

Happy Voyaging!

Please comment at our Forum!