Kidou Senshi Crossbone Gundam Koutetsu no Shichinin

While in their usual patrolling duty, the Crossbone Vanguard managed to find jovian forces trying to kill an escapee. While rescuing the woman, they happen to stumble in Jupiter's newest "wipe out the entire world" scheme. Unlike the previous times, they actually are too late to organize counter measures and there is almost no hope of stopping them due to many adverse circumstances.

...The pirates must now fall back on desperate plans, taking huge risk while trying to stop the abominable "Zeus Thunder" project before mother Earth is completely engulfed by the flames of war.