When will the game be released?

I hope to release a demo in 2025, but for the full game there is no fixed release date yet since there is still some work left to do. You can wishlist it on Steam to get notified when it gets released. This also helps me reach more players by boosting visibility on Steam.

What operating systems are supported?

Currently GNU/Linux and Microsoft Windows are supported. Steam Deck has not been tested, but the graphics are likely to be too demanding for it.

What are the system requirements?

You need at least a graphics card with passmark 10000 such as the Nvidia GeForce GTX 1060. The hardware requirements might still change, but the main bottleneck are the volumetric clouds.

Also ideally you will use a joystick or a game controller for controlling the space craft.

What features will the full game have?

Planned features are vertical launch, space station docking, moon landing, atmospheric reentry, and landing on a runway. It is also planned to have flight instruments to support the different stages of flight.

Is the game free software?

Yes, the game is free and open source software (EPL-1.0). The source code is available on Github. It makes use of Clojure, LWJGL, Fastmath, Jolt Physics, and other libraries. The celestical positions are implemented according to Skyfield. Note that building the project assets takes several days on a modern computer.

Can I use the source code in my own project?

Yes, same as Clojure, the project is released under EPL-1.0. The Eclipse Public License 1.0 is a weak copyleft open source license that allows modification and distribution of code, requiring that changes to EPL-licensed code be shared under the same license, but allowing proprietary use of combined works.

Note that if you just want to study the source code, you do not need a license. I.e. you are not bound by the license if you just want to study the source code and reimplement concepts in your own project.

Who made the music?

The free (CC-BY 4.0) music is made by Andrewkn! Andrewkn’s main styles are ambient, сhillout, drone, and cinematic.

Will there be support for virtual reality headsets?

At the moment, VR support is not planned.

Where is the Earth data from?

The game uses accurate data from NASA Blue Marble, NASA Night Lights, and NOAA elevation data.

Do you use realistic positions of Sun, Moon, and Earth?

Yes, the game uses ephemeris data from NASA JPL. The relevant interpolation software was translated from Skyfield.

Where is the spacecraft model from?

The spacecraft model was created using Blender and is inspired by the real-life Venturestar single-stage-to-orbit project which was never launched.

When did development of this game start?

Development is fairly slow because it is a hobby. The first commit to the sfsim repository happened in September 2020. There also is prior work on model rendering in 2017. Also I made two attempts at implementing a physics engine using sequential impulses in 2017 and 2020.