The Orbiter meshes for the Percival Lovell and space stations were for a very old version of Orbiter and are not currently supported. Check out the Orbiter Hanger, Orbiter Forum, and main Orbiter page for more information about the latest in Orbiter.

As both Brian and I run Ubuntu these days, it is unlikely that any new development for Orbiter will happen, at least until Orbiter is finally Open Sourced and ported to OpenGL and Linux.