Spatial discriminators were components of Earth vessels' stabilizers in the 22nd century. In 2153, Travis Mayweather reconfigured the spatial discriminators of his family's ship, the ECS Horizon, in order to increase the effectiveness of the ship's port stabilizers. However, as he did this without authorization from Paul Mayweather, Travis's brother and acting captain of the Horizon, a certain amount of friction became evident between the two of them. (ENT: "Horizon")