The technology and science behind space ship weaponry.
A pilot that specializes in soldiering in general becomes very well versed in gunnery and manouvering skills. Training will focus entirely on efficiency in combat, training of combat-relevant attributes and to learn better to sustain damage. After training, a soldier can turn to anything he wants There are no preset paths. But if a soldier keeps on advancing the skills alotted in the beginning, corporations, alliances, agents and the like are always looking for people with an accurate targeting eye and sensitive trigger fingers to do their bidding. There are always wars to be fought somewhere for those willing! Also, there is good cash to be made from hunting pirates that infest asteroid belts throughout space.