Great Breakout
From Tardis Wiki, the free Doctor Who reference
The Great Breakout was a period in history, around the year 5000, in which humanity spread out to the stars. This also meant the solar system became more busy, as large amounts of frontiersmen and pioneers got concentrated in the asteroid belt while waiting to spread out in the Galaxy.
The Doctor noted the spread of disease was a significant downside to this expansion. (DW: The Invisible Enemy)
