Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Excellent hard science fiction

I enjoyed Ship of Fools immensely. Russo crafts a believable 'generation ship' and then dives into the machinations of different political and religious factions on board. The story is told from the perspective of an unusual protagonist, which serves to highlight the tension and claustrophobia, especially once they make planetfall. The encounter with the alien ship is very well handled and original. Overall this book is a great read. Once I got into it, I couldn't put it down.