I, Voyager


What is I, Voyager?

I, Voyager is

  1. an open-source software planetarium
  2. a development platform for creating games and educational apps in a realistic solar system.

It is designed to be improved, modified and extended by the community. I, Voyager runs on the open-source Godot Engine and primarily uses Godot’s easy-to-learn GDScript (similar to Python). It can be extended into an independent free-standing project (a game or other software product) using GDScript, C# or C++.

If you are interested in our future development, see our official Roadmap!

What does I, Voyager cost?

I, Voyager is free to use and distribute under the permissive Apache License 2.0. Projects built with I, Voyager are owned by their creators. You are free to give away or sell what you make. There are no royalties or fees.

How do I contribute to I, Voyager development?

Help us grow the community by following us on Twitter and Facebook. Exchange ideas and give and receive help on our Forum. Report bugs or astronomical inaccuracies at our issue tracker here. To see where we are going and how you might help, visit our official Roadmap. Or contribute to code development via pull requests to our repositories at github.com/ivoyager.

How can I support this effort financially?

Please visit our GitHub Sponsors page! Become a Mercury Patron for $2 per month! Or, if you are a company, please consider sponsoring us as a Saturn or Jupiter Patron. Goal #1: Make I, Voyager into a non-profit entity! This will shield us from tax liability, allow us to apply for grants, and secure our existence as a collaborative open-source project into the future.

Where did I, Voyager come from?

Creator and lead programmer Charlie Whitfield stumbled into the Godot Engine in November, 2017. By December there were TestCubes orbiting bigger TestCubes orbiting one really big TestCube*. The name “I, Voyager” is a play on Voyager 1, the spacecraft that captured an image of Earth from 6.4 billion kilometers away. I, Voyager became an open-source project on Carl Sagan’s birthday, November 9, 2019.

(* Godot devs, bring back the TestCube!)

Authors, credits and legal

I, Voyager is possible due to public interest in space exploration and funding of government agencies like NASA and ESA, and the scientists and engineers that they employ. I, Voyager is also possible due to open-source software developers, and especially Godot Engine’s creators and contributors. Copyright © 2017-2023 Charlie Whitfield. I, Voyager® is a registered trademark of Charlie Whitfield in the U.S. For up-to-date lists of authors, credits, and license information, see files in our code repository here or follow these links:

  • AUTHORS.md – contributors to I, Voyager code and assets.
  • CREDITS.md – the people and organizations whose efforts made I, Voyager possible.
  • LICENSE.txt – the I, Voyager license.
  • 3RD_PARTY.txt – copyright and license information for 3rd-party assets distributed in I, Voyager.

Screen captures!

Our site header for ivoyager.dev is also from the Planetarium!

I, Voyager screen capture of Jupiter and Io viewed from Europa.
Jupiter and Io viewed from Europa. We’ve hidden the interface for one of the best views in the solar system.
Image of Jupiter embedded in the orbital paths of its many moons
Jupiter and the four Galilean moons – Io, Europa, Ganymede and Callisto – embedded in the orbital paths of many smaller moons.
I, Voyager screen capture of Saturn's rings and its close-orbiting moons.
Saturn’s rings and its close-orbiting moons.
I, Voyager screen capture of Uranus' moons from the "north". Uranus' 98° axial tilt puts the solar system almost directly to the south.
Uranus’ moons are an interesting cast of characters (literally). The planet’s 98° axial tilt puts the inner solar system almost due south in this image.
I, Voyager screen capture of the solar system showing outer planets and Pluto on July 14, 2015, the day of New Horizon's Pluto flyby.
Here’s the solar system on July 14, 2015, the day New Horizons flew by the dwarf planet Pluto (♇). Not coincidentally, Pluto was near the plane of the ecliptic at this time.
I, Voyager screen capture of Pluto and Charon.
Pluto and its moon Charon to scale. Both are tidally locked so their facing sides never change.
I, Voyager screen capture of Main Belt and Trojan asteroids from above.
Jupiter (♃) is the shepherd of the Solar System, as is evident in the orbits of asteroids (64,738 shown here). The Main Belt (the ring) and Trojans (the two lobes leading and lagging Jupiter by 60°) are the most obvious features here. Hildas are also visible. I, Voyager has orbital data for >600,000 asteroids (numbered and multiposition) but can run with a reduced set filtered by magnitude.
I, Voyager screen capture of Main Belt and Trojan asteroids from the side.
Main Belt and Trojans viewed from the side. We use the GPU to calculate and update asteroid positions (each asteroid is a shader vertex that knows its own orbital parameters).
The Planetarium has easy-to-use interface panels that can be hidden.
For developers, we have a large set of GUI widgets that know how to talk to the simulator. These can be easily dropped into Containers to make your custom GUI however you like.
Here’s our “starter GUI” in the Project Template to get you going on game development.