A hyperspace jumpzone, more commonly referred to as a hyperspace jump point, was the point in which starships engaged their hyperdrive and entered hyperspace. This could only be done after programming the jump coordinates into the navigational computer. This was the last point any communications could be sent or received before the hyperdrive engaged. The opposite of this point was a hyperspace , where ships exited hyperspace and entered realspace. During the Battle of Coruscant, General Grievous placed mass-shadow mines along the reversion points in the area to prevent Republic reinforcements from arriving.