Orbital simulation

Is there a good free orbital simulator for Linux? I don't want a game like KSP but a simulation of orbits without much need for fancy graphics. I am wondering what the orbit of a ring would be like (EG a Dyson ring) and whether it's plausible to make such a ring or whether a set of disconnected sattelites in the same orbit is required. -- Sent from my Nexus 6P with K-9 Mail.