CONCEPT
Aurora
Aurora is the model Spacer world: a planet settled three millennia before Asimov's narrative present, with a population of around two hundred million humans and roughly fifty robots per human. The political and cultural center of the Spacer civilization, it presents a more sustainable form of the robot-dependent arrangement than Solaria's extreme case. Auroran life is comfortable, long-lived, and culturally conservative; robots are ubiquitous but human-human contact remains normal. Aurora is the version of the Spacer pattern that could plausibly last, as against Solaria which cannot.
In The You On AI Field Guide
Aurora's role in Asimov's larger timeline is to be the mature expression of the Spacer project. Earth has retreated into Cities; Solaria has gone feral in its isolation; Aurora has stabilized. It is the benchmark against which both extremes are measured. Its political institutions work. Its economy is productive. Its citizens, while long-lived and robot-served, remain capable of meaningful cooperative action.
The novel The Robots