Busuyuria

The Busuyuria (jap.: 自翔弾)(Baronh: ブスューリア Busu~yuria) is the term for a self-propelled bomb.

Background
It is an unmanned weapons that can move on its own. The warhead is probably a fusion bomb. Unlike a mobile mine it does not have a space-time generator, hence, it cannot be used in plane-space.