Drifter

The Drifters is the group of humans who reject the Galactic Alliance of Humankind for various reason and don't join them. Little is known about the Drifters but based on Ledo and Chamber's conversation the Drifter has much more advanced technology than The Earth people and on pair with the Galactic Alliance of Mankind.

Based on the analysis of Chamber when Ledo initially became trapped on Earth, the Drifters have several space colonies and space stations.

Trivia

 * While Ledo and Chamber discuss the Drifters, none are ever directly encountered during the animated series.