"The Undying Fire" by Fletcher Pratt

Space-pilot Paulsson was in trouble. He had been accused of dereliction of duty. He knew it wasn't true, but he also knew there was no point in fighting back directly. The only way to re-instate himself was to make a successful expedition to the young planet Danaan. And whether he could do that, no one knew. Least of all Paulsson.

One of our master science-fiction writers, very much at home in a world of interplanetary communication, psychological conditioning and colonized planets, unfolds an adventure of the future that ranks with his best. (GoodReads)