This is a long shot in the dark, but make sure the laser's appear green in your list of weapons on your hud while in space. to make em go green or white (turn em on/off) just left click the mouse button on them.

Another possibility, is that you sold your first weapons and have not mounted new weapons you looted from the NPC. To mount them goto the equipment dealer look at the weapons in your hold and make sure they are mounted, left click the mouse button on the little box like symbol of the weapons picture.