What is the theme in Rocket Boys: A Memoir by Homer Hickam?

Hope is a recurrent theme in the story of Sonny and the other rocket boys. In the beginning, none of the boys have much hope of a life outside of Coalwood. In Coalwood, West Virginia, a town that only seems to care about mining coal and high school football, boys generally grow up to become miners or join the military. When Sonny builds a rocket, and accidentally blows up his mom's backyard fence, in a blur of wooden splinters and burning debris, his father's greatest surprise is that Sonny attempted to build a rocket.