Cubic kilometer
A cubic kilometer (km3) was a unit of  defined as a cube measuring one kilometer on each side.

Comparative list of volumes 
 28 cubic kilometers: The Borg cube encounter by the  measured twenty-eight cubic kilometers in volume and was populated by twenty-nine thousand Borg drones. ()

 80 cubic kilometer: The destruction of the Vostigye space station created a debris field encompassing nearly eighty cubic kilometers of space. ()

 20 million cubic kilometers: Later, while charting the Arachnid Nebula, the Vulcan Tolaris later told Captain Jonathan Archer that he was "eager to get back to work" because they still had another twenty million cubic kilometers to chart. ()

See also 
 Cubic kilometers per hour

External link 
 
Measurements