the galat MWI-55 space mine is a gigantic floating mine that works both in space and in atmosphere, yet is designed for space and might not perform as well in atmosphere. It is pretty big, about the size of a quarter of a chicken class spacecraft carrier. Its explosion radius is quite big as well. when a target is detected, it flies to it at max speed and hits it.
something for my nation in RMG its explosion has a small mix of anti matter and dark energy added to its explosion to enhance the damage along with releasing tons of shrapnel. it can also be moved through the air via a remote control so it can be used as a giant FPV drone yet this is rarely done and for the most part it simply is left floating.
