Shadows in Flight by Orson Scott Card
At the end of Shadow of the Giant, Bean flees to the stars with three of his children - who share the engineered genes that gave him both hyper-intelligence and a short, cruel physical life. The time dilation granted by the speed of their travel gives Earth's scientists generations to seek a cure, to no avail. In time, they are forgotten. But the Delphikis are about to make a discovery that will let them save themselves, and perhaps all of humanity in days to come. For there in space lies a derelict Formic colony ship, and aboard it, they will find both death and wonders.