Self - replicating mine The self - replicating mine was a defensive explosive device invented by Miles O ' Brien , Rom , and Jadzia Dax in 2373 . The mines were deployed in a field around the entrance of the Bajoran wormhole , to prevent any further Dominion reinforcements from coming through . Each mine was cloak ed and extremely small , no more than a meter across , which prevented advanced Dominion sensors from detecting them . More importantly , the mines were equipped with a replicator unit , such as that every mine that was detonated or deactivated would be immediately replaced by its neighbor . The mines were programmed to swarm - detonate , to compensate for their small size . ( ) Due to the possibility of the mines ' proximity sensor s causing premature detonation , the entire minefield had to be put in place before the mines could be activated . The Dominion sent a fleet to prevent this from happening , but cover fire from Deep Space 9 and the allowed the to complete the task . The activated minefield proved an effective barrier to the Dominion even after Deep Space 9 was captured . This frustrating obstacle prevented the Dominion from overrunning the Alpha Quadrant . ( ) Eventually , Damar found a way to deactivate the mines without having them replicating themselves , by isolating them one at a time with an antigraviton beam projected from Deep Space 9 ' s deflector array . Fortunately , through Morn , Kira Nerys gave Starfleet information on the deactivation of the minefield . Faced with the prospect of overwhelming Dominion reinforcements through the wormhole , Starfleet launched Operation Return , sending all its available ships to destroy the deflector before the deactivation process was completed . Unfortunately , the " Defiant " arrived too late to prevent Gul Dukat from detonating the minefield , forcing Sisko to send the " Defiant " into the wormhole to confront the Dominion reinforcements . ( ) Appendices . Background information . The props for the self - replicating mines were originally rolling composters obtained by Laura Richarz that were only slightly modified . The composters pop up again in the background of many episodes , mostly as cargo containers . " ( ; ) According to , the mines were labeled " ALH 84001 " as a reference to the meteorite , which was found in to have fossils of micro - bacteria from Mars . In the " " more detailed information is given of the self - replicating mines . Their shells are described as duranium cargo containers . They are cloaked with miniature cloaking devices and have proximity and contact sensors for detonation with a neutrino source counter for distance keeping with one another , a thruster system of a class - 1 probe with a single fuel source designed for station keeping and a combiner tank with a premixed charge of a standard photon torpedo warhead serves as the explosive . The replication system is further explained as well . Each mine has initially only 1 / 65 of the material stored in them for a single replacement mine . Replicators however transfer material to one another where it is needed in the field through networking . As stated in , the neighbor of a detonated mine does seem to replace the lost mine in the end , material however comes from at least 65 different mines . As stored material begins to run out the mines have a zero - point extraction system for matter replenishment . Based on the figures given in the manual , the field laid out by the " Defiant " contained some 165 , 000 mines altogether . Judging from the visual effects in the episodes this isn ' t so far fetched . It is unclear if the use of cloaking devices in mines violated the Treaty of Algeron . There has never been any specific reference to this type of use being banned and the Romulans signing the non - aggression pact with the Dominion in the same episode may also have been a factor . The Federation has also been observed using isolation suit s and a cloaked holoship in . Apocrypha . In the novel " The War of the Prophets " , Garak reflects that , when he first heard about Rom ' s role in designing the minefield , he was so impressed that he actually used some of his intelligence contacts to determine if Rom was actually living under an assumed name to escape the burdens of a genius past , but is forced to concede that Rom appears to be exactly what he claims to be after his search efforts reveal nothing untoward . In Greg Cox ' s " Tales of the Dominion War " short story " Night of the Vulture " , a Cardassian double agent on Earth obtains the codes from Starfleet to deactivate the minefield . En route to Terok Nor , however , the ship transporting the spy and a Founder is attacked by the Beta XII - A entity . Everyone aboard is killed , although the ship and the entity are pulled into a spatial rift .