This spherical_robot isn't a small version of an Orbital_Battle_Station.
A Death Star is intended to be the size of a moon.
However, the spherical+droids can be just as intimidating & menacing as any Death Star.
http://starwars.wikia.com/wiki/DRK-1_Dark_Eye_probe_droid,
http://en.wikipedia.org/wiki/Star_Wars:_Droids
http://science1.nasa.gov/science-news/science-at-nasa/2006/01jun_spheres
http://en.wikipedia.org/wiki/Robotics#History_of_robotics
http://www.sciencedaily.com/news/computers_math/artificial_intelligence
http://www.aaai.org/home.html
https://www.edx.org/course/uc-berkeleyx/uc-berkeleyx-cs188-1x-artificial-579
http://thedigitallabyrinth.blogspot.ca/2013/12/humans-robotics-and-bionics.html