The Mobile Defense Station (MDS) was the logical succesor to the C-Defender and Deron War Craft's line of Orbital "Defense Stations". It has a heavely armored front end which looks like a half of the Defense Station 3. It is about 3 times larger than the C-Defender, but it's increased size allows for more lasers to be fitted on the craft.
On Derazuma IIEdit
On Derazuma 2, MDSs are stored in underground facilities. In the event of a raid, the MDSs would be deployed in a sphere formation, surrounding the planet with a big wall of lasers and armor.