In the 48th century,a stardrive was invented that let man go where no human had gone before, and he got to take everything with him.
It let humanity go beyond this galaxy,and yes, we had stardrives,but these were only for small ships carrying a few thousand souls.
But after the conversion from gravity drives to drives powered by a gravity well, all this changed.
It was found that when applied to different areas of a city, the city could in fact leave the earths gravity and travel between galaxies.
And as a side effect of the drive came the force field that extended itself around the whole thing.
So we had flying cities,the down side of this was if a city left Earth it would only exist in the coldness of space.
Still there were those who welcomed this,they could do their own thing without interference.
One such faction were the Communistic Alliance,even after centuries of change and peace, they still kept “political dissidents” in labor camps.
So the city of Karl Marx left the Earth for who knows where,I think the planet will be a nicer place with them gone,the only downside was we were unable to stop them taking their prisoners with them.
These photos were taken from moon base Alpha as the city left Earths orbit.