Worlds Enough and Time
by Joe Haldeman

Description:
"Worlds Enough and Time deals with Marianne as a middle-aged woman and elder, participating in the voyage to Epsilon, working essentially as a city manager for this very odd city: ten thousand people inhabiting an area about the size of a shopping mall, knowing they will never go outside; knowing that their lives depend on complicated life support and propulsion systems -- and if something goes wrong, there's no way to send out for spare parts. Stir- craziness is the order of the day.

Technology intervenes, for good and ill. Marianne arrives on the planet still fairly young, and when they meet the aliens who already live there, she's presented with a challenge larger than any human has ever faced." -author