Space Trajectory Analysis
Space Trajectory Analysis (STA) is a graphical astrodynamics application from the European Space Agency. It is based on the rendering engine of Celestia.
STA is distributed as binary packages for Linux, Windows and Mac. Of those, I only had luck with the Windows version and even that seems to run slightly bad. So, next step was to try and build the sources available directly in the SVN repository. Sadly, the build scripts are slightly broken or incomplete (Qt-based .pro files) and do not build out of the box despite the instructions I got here.