Playing around with one of my save games I found that you can change your ships six digit i.d. tag that's usually three letters, a dash, then three numbers.
Personally I use notepad++, but any reader should work. You have to have what your current ships i.d. number is in-game. Open your save file and find the instance of those digits. In a fairly new game I only had 1 instance of it, there may be more depending on your length of playing the game. Use the find/replace option and enter your current i.d. including the dash and replace it with any six letter word that you want. (IE: replace SUK-101 with REA-PER) you do have to use the dash in-between the first three digits and the last three.
I haven't tried it out with spaces or specialty characters so I don't know if they will work as well...
wordfinder.yourdictionary.com has a list of over 15,000 six letter words in the English language.