Best Source selection has become a major desire at many flight test and launch ground stations around the world today. Current Diversity Combiners in the receivers deal with a single antenna. This limits the reception because a single antenna provides only one angle on the vehicle. This paper describes the evolution of best source selection as well as the huge advantages that can be achieved through the Diversity Combining of multiple antennas with spatial diversity. Data Correlation as well as different data quality measurement techniques are discussed and actual measured performance gains are presented.