Technological achievement
Throughout the early centuries of the Diaspora, a major limiting factor was the expense of terraforming and arcology technology - the most viable colony prospects were planetary bodies requiring a minimum of terraforming.
In 2484, Kuem Wi Consolidated announced the development of Huxi Leung terraforming technologies, which reduced the time and cost of terraforming previously-marginal prospects for colonization.
In 2489, the Olto-Nagny patents revolutionized orbital arcology creation, making it possible to use artificially-constructed orbital bodies as the basis for arcology construction.
These new technologies revolutionized the evaluation of colonial prospects and the development of habitable space, and set off another wave of the Diaspora that lasted from the late 25th through the mid-26th Century.