The Self Healing Nlinefield (SHM) is comprised of a networked system of mobile anti-tank landmines. When the mines detect a breach, each calculates an appropriate response, and some fire small rockets to "hop" into the breach path, healing the breach. The purpose of the SHM is to expand the capabilities of traditional obstacles and provide an effective anti-tank obstacle that does not require Anti-Personnel (AP) submunitions. The DARPA/ATO sponsored program started in June 2000 and culminated in a full 100-unit demonstration at Fort Leonard Wood, MO in April 2003. That program went from "a concept" to a prototype system demonstration in approximately 21 months and to a full tactically significant demonstration in approximately 33 months. Significant accomplishments included the following: (1) Demonstration of a working, scalable (order of a hundred nodes), ad hoc, self-healing RF network. (2) Demonstration of an innovative distributed time synchronization scheme that does not rely on GPS. (3) Demonstration of a non-GPS based, self-mapping, relative geolocation system. (4) Development of an innovative distributed safe, arm, and fire system that allows for independent firing of eight rockets within a single node. (5) Development of a small rocket design with a novel geometry that meets the propulsion requirements.