You can unlock special ships, and contacts by completing these achievements. When you complete one it is always available for future games on any difficulty. The below list is what was available on 8/9/18. You should expect it to grow dramatically.
I was building a brand new custom Template. I set contacts at priority A giving me 8 to start the game with. During contact selection. The Academy Doctor appeared on the list as locked. Wow! I sure want that contact.
But I would have to exit all the way out before completing my template to find out which achievement will unlock the Academy Doctor.
Not particularly elegant, but works for me.
1.) Start STF in Windowed mode.
2.) Open this forum thread in a new tab. Now you can switch back and forth while creating your new template.
3.) When finished, return to STF menu select options ==> Fullscreen and restart.