Can anyone tell me why Catia V5 can't save/export or open/import .sat files. What chances do i have to bring a .sat files into Catia V5 without an external converter?
Possibly for the same reasons that you cannot open (or save) SolidWorks files with Catia. Catia has a different kernel as to that of SolidWorks and therefore most likely also other programs like in this case Spatial/ACIS. As to exactly why (if that is still relevant to you), I'd reccommend you send an inquiry to Dassault Systems and Spatial.
Does it have to be .sat files? Can you export the files from Spatial as .stp then import that into Catia instead? Saves you one process at least...