Mobile Suit Gundam Wing: Ground Zero

After a generation of warfare, the Gundam boys finally secured a peace between Earth and the colonies by helping to defeat the Oz and White Fang armies. Now, out of the rubble, the surviving soldiers are re-emerging and clustering together into new factions. Heero Yuy has become a vigilante pacifist, tracking down weapons stashes and destroying them, while Relena, former Queen of the Earth Sphere, tries to maintain the peace politically. But an unmanned weapons factory has been discovered somewhere near Mars, and now the boys are going to have to dust off their mechs for one more battle to save the tenuous peace. 
(Source: Tokyopop)

Summer AC 196, the Earth Sphere Unified Nation begins the long process of disarmament with Relena Darlian leading the preceedings. However, something troubles the Gundam pilots; rumors fly about Vulkanus, an OZ manufacturing plant, full of Mobile Dolls and lost somewhere in space. In the meantime, an organization called the Perfect Peace People is calling for even further measures of disarmament than even Relena herself. The Gundam pilots set out to find and destroy Vulkanus before anyone can get their hands on it and use it for their own purposes.