Old space game for PC?

I can't remember what it is called.. I played this computer game some 15yrs ago, it's very simple graphics. Set in space you fly to planets and mine just 3 minerals or resources on them which looks like 3 columns green yellow and red(or brown). Some planets r radioactive. The battle with other ships looks like being on the grid. It's not master of orion or star control. i wud appreciate answer very much.