Gaia Sky is a real-time, 3D, astronomy visualisation software that runs on Windows, Linux and macOS. It is developed in the framework of ESA's Gaia mission to chart about 1 billion stars of our Galaxy in the Gaia group of the Astronomisches Rechen-Institut (ZAH, Universität Heidelberg).
See:
https://zah.uni-heidelberg.de/de/instit ... s/gaiasky/
Source-code:
https://gitlab.com/langurmonkey/gaiasky
Edit: someone should develop a generation ship management simulator on top of that... all Hard SF style