Conflict
Homer thinks that Sonny is just average in everything, that in no way will he ever surprise people. Although it is never stated, Sonny is driven by his father's opinion of him. Sonny is determined to prove his father wrong, to make Homer proud of him.
Resolution
In the end, Sonny and his friends accomplish national recognition with their work on rockets. By doing this, Sonny does things his father never thought possible. Sonny earned scholarships to college, and went on to do great things with his life. Sonny made his dad proud, even if Homer never thought it possible.