"Why the latest New Horizons Flyby represents a space exploration milestone" PBS NewsHour 1/1/2019

Excerpt

SUMMARY:  On this New Year’s Day, NASA has a special reason to celebrate: Its spacecraft New Horizons has made a successful Flyby of Ultima Thule, an object orbiting in space about four billion miles from Earth.  Science correspondent Miles O’Brien joins Jeffrey Brown to explain the immense difficulty of this mission and its larger significance for the U.S. space program.