First off, please do not ressurrect threads that have been laying dormant for 8 years.
Secondly, the last TrueSpace version to be released for free is 7.6, which you may still be able to find via Google; be aware however that Truespace has been discontinued and is no longer supported.
It also has various known issues when used to produce models for FreeSpace, assuming that is something you want to do. If you want to do 3D modelling, why not use SketchUp or Blender? They're equally free, but have far fewer issues, and are still supported by their creators.