However, it's a common abbreviation and it would be nice if was made into a synonym of kerbal-space-program.
You can suggest a synonym for Kerbal Space Program (you have enough reputation to do so, and you have a 5+ answer score for the tag). However, I believe the ksp has to actually exist before it will allow you to suggest it. At the moment, it currently does not.
After you suggest the synonym, it has to be voted on. Four votes will get the synonym created.