Ah, I've beaten it on hard, its you have to be reasonably fast and you have to prioritize.
Go for your listed objectives FIRST. After that, you can do whatever you like until the blight comes to eat you. Or is it a volcano? I can't remember which.
*Hint: Research Rare Ore Processing FIRST!
You don't have to fill the food and ore objectives right away, that can wait until the end of the mission (Right before you get horribly pwned). This allows you to full fill your other objectives and complete as much of the research tree as possible.