I'll fall back for now on the couple of paragraphs that accompanied our casting announcement for Gaitanis,
back in October 2009:
Humanity has not discovered an abundance of “new Earths” orbiting other stars - most worlds upon which human beings can live at all are barely habitable. The emigrants from Earth - not all of them voluntary pioneers - who’ve populated the mining worlds and marginal factory planets have adapted themselves through genetic surgery and technological enhancements to survive in places inimicable to life itself. Now a new cadre of leaders have arisen on these worlds, harnessing ages of resentment and rebellion to form the Transhuman Authority and launch a war of conquest against Earth and its United Worlds allies.