It was an E-4. They do touch & go's all the time at Eppley, no big surprise. They are based at Offutt AFB
, so they are not an uncommon sight in the sky above Omaha.
The E-4 is an airborne command plane, possibly used by the President or high-ranking military officials during times of nuclear war. Details are classified, of course.
To most people, the sky is the limit. To those who love aviation, the sky is home