The 3rd Mars Interceptors were a Terran Defence Authority unit of SSF 21D Cutlass Mk. IIs stationed in Syrtis Major during the Proxima Wars. It was presumably a part of the Mars Defence Group. During the Battle for Mars the unit's refuelling station was hit by Proximan warheads; only the quick thinking of Major Sven Erikson, who immediately launched his Cutlass, R2, and destroyed two Proximan ships saved the base and its ships from destruction.