Hyperspace

Hyperspace is the volume of four-dimensional space above (with a lower gravity constant than) n-space. Access to hyperspace is only possible for humans through the use of an Icarus engine, which requires exponentially more energy to access higher altitudes. Conversely, the n-space speed of an object increases relative to their hyperspace band at a gradient of pi, leading researchers to believe hyperspace is a curved plane or, as seen in fold corridors, a sphere.