In addition to what Irene came up with, try _Star Guard_. I think he was tried, but not for heresy. I was also thinking of _Star Man's Son_. He was tried in that one, but, while in the future is not futuristic, being set in a post-collapse society, i.e. no star voyage at the end, although he did end up with a high position.

: But I still can't think of match to the bit about being deliberately outcast until the time is right.

In Star Man's Son, the hero was outcast, but for his crime of stealing his father's StarMan's pouch.

Paul.