Ive managed to create a batch file to make a copy of my save, and timestamp it, ive attached it to one of my spare mouse keys, i could also set it up to run every 30 mins or so, that should help sort that out.
Incase anyone wants this, copy the below text into notepad, and save as Terratech backup.bat (changing steam username directory):
@echo off
for /f "delims=" %%a in ('wmic OS Get localdatetime ^| find "."') do set dt=%%a
set YYYY=%dt:~0,4%
set MM=%dt:~4,2%
set DD=%dt:~6,2%
set HH=%dt:~8,2%
set Min=%dt:~10,2%
set Sec=%dt:~12,2%
set stamp=%YYYY%-%MM%-%DD%_%HH%-%Min%-%Sec%
copy "C:\Program Files (x86)\Steam\steamapps\common\TerraTech Beta\Saves\Ashar\game.sav" "C:\Program Files (x86)\Steam\steamapps\common\TerraTech Beta\Saves\Ashar\game - %stamp%.save"
BTW found this site with a free app for turning batch files into exe's that can run silently, without making the game minimize:
http://www.battoexeconverter.com/ (Its virus free)