The star systems surrounding Super Earth are besieged by both bug and machine. It's your job, cadet, to liberate those hostile systems, one planet at a time.
Each planet has a large number of operations of varying risk levels to undertake. As you prove your skill in more trivial skirmishes, you'll earn the right to tackle more dangerous incursions, where the rewards for your squad will be ever greater.
The galactic map in every ship charts the progress of our military efforts and only by liberating one planet and system after the other can we hope to secure freedom galaxy-wide.