This is the awesome Gundam piloted by Quatre Raberba Winner.
During the events of Mobile Suit Gundam Wing: Endless Waltz,Quatre and the other three Gundam pilots, save for Wufei, decided to send their Gundams into the sun through the mobile asteroid Vulkanus. However, in AC 197 the Barton Foundation upsurped the pacifist Earth Sphere Unified Nation and abducted its leader, Representative Relena Darlian. To combat this new threat, Quatre, after dispatching Wing Zero to Heero, redirected the course of Vulkanus so that it would not collide with the sun. Later, Quatre, Trowa, and Duo retrieved their respective Gundams from the asteroid and traveled to Earth to assist Zechs Marquise and Lucrezia Noin who were fighting an army of Serpent mobile suits in Brussels, Belgium. After the Marimeia Conflict was over, Sandrock was self-detonated alongside Deathscythe and Heavyarms.

Source:http://gundam.wikia.com/wiki/XXXG-01SR2_Gundam_Sandrock_Kai