OK, can anyone let me know how you are supposed to use the scanner in the prospecting missions please.

This should probably go in the FAQ thread: I've heard a lot of people ask this in game.

First of all, before taking the mission you *must have an empty s-port slot on your ship!* To do this go to the "ship" tab in the station interface and select any weapon you might have equipped on an s-port (if you are using a bus it will be the only weapon you have equipped). Then click the "unequip" button below the equipment inventory window. The weapon slot you selected should now read "EMPTY."

If you accepted the mission before having an empty s-port you have no choice but to abort the mission and unequip your weapon before trying again.

Now go to the "missions" tab and take the prospecting mission. A special scanner will automatically be loaded into your vacant s-port. To use the scanner get to within 500m of an asteroid and click your primary fire button. A message will appear under your Mission chat tab (activated by pressing shift-2) that tells you if you found any minerals.

Small correction: The scanner is now put into the station hold if you don't have a free slot.