Super Dimensional Cavalry: Southern Cross (1984)

In the far future, a human colony planet called Glorie comes under attack by an alien race called the Zors. The focus characters of this series, Lt. Jeanne Fránçaix and the 15th Armoured Tactical Unit which she commands, quickly prove to be one of the most effective combat units in this war, despite their reputation as troublemakers. In the course of the war, they play a key role as the entire Army of the Southern Cross fights a seemingly hopeless battle against an apparently near invincible enemy. Yet secrets and tensions are hidden in the enemy itself which could profoundly change the conflict on their own.