I don't think there is one specifically made for Traveller First-In, but here is the link to the free tools from SJGames that would have GURPS Space versions:
http://www.sjgames.com/general/gm-aids.html
Have you tried the Heaven & Earth Traveller application? I believe it'll generate star systems in the traditional Traveller way using Traveller rules (I think pre-Mongoose era):
http://www.downport.com/wbd/HEAVEN_&_EARTH.htm
I found a newer Python version for GURPS Space star generator that looks promising as well:
https://github.com/tschoppi/starsystem-gen