A cargo spacecraft performs an in-line docking maneuver with a space station along an axis where the station's docking port is fixed at \(x = 0\). The spacecraft approaches from the positive \(x\)-direction, and its velocity \(v(t) = \dfrac{dx}{dt}\) relative to the station is shown in the graph: a constant velocity of \(-4\text{ m/s}\) from \(t = 0\text{ s}\) to \(t = 4\text{ s}\), a linear change to \(+2\text{ m/s}\) at \(t = 10\text{ s}\), a linear change to \(-2\text{ m/s}\) at \(t = 14\text{ s}\), and a linear return to \(0\text{ m/s}\) at \(t = 18\text{ s}\). The spacecraft successfully latches to the docking port at \(x = 0\) at time \(t = 18\text{ s}\). What was the initial separation distance between the spacecraft and the docking port at \(t = 0\text{ s}\)?