Fleet of Worlds is a book in Larry Niven's Known Space series. The Fleet of Worlds series, consisting of this book and its four sequels, is named for its opening book.
Worlds closer to the galatic core than Known Space are --or were-- home to intelligent speciers. Some learned of the core explosion in time to flee. Destroyer of Worlds opens in 2670, ten years after Juggler of Worlds closes; with refugee species fleeing in an armada of ramscoops in the direction of the Fleet of …
Kyle Gustafson had been doing work he loved, with the space program, anemic though it was, until disaster struck and a shuttle was lost on takeoff. There had to be a fall guy, and Kyle was picked-but a few months later, the American space program instantly became a quaint relic when aliens in a gigantic starship …