The Mars Defense Perimeter was a Starfleet defense mechanism, designed to protect the inner planets of the Sol system, and specifically Earth, from intruding hostile vessels. Part of the defense perimeter is a series of attack ships.
In early 2367, an attacking Borg cube crossed the perimeter and was able to easily break through the defensive lines. Damn shame too i realy wanted to see what them ships looked like but were killed too fast! (TNG: "The Best of Both Worlds, Part II")
- The Mars defense vessels were made from models of Typhoon- and Los Angeles-class submarines.