A spatial matrix was a component of the Bajoran wormhole, the stability of which was directly related to the wormhole's ability to open and allow vessels to pass through. In 2373, in an attempt to prevent Dominion reinforcements from arriving through the wormhole, the crew of Deep Space 9 fired a phase-conjugate graviton beam at it in an attempt to collapse its spatial matrix and close it forever. Due to sabotage by a Changeling posing as Doctor Julian Bashir, however, the beam had the exact opposite effect, strengthening the spatial matrix and making it impossible to collapse. (DS9: "In Purgatory's Shadow", "By Inferno's Light")