I wanted to like this book more than I actually did. I heard the author speak on a panel, and I loved her description of the book so much I bought it without reading any reviews. It needed up being much more of a YA teenage feelings story than the hard science sci-fi I was expecting. In the beginning we meet seven British teenagers, all graduates of an exclusive astronaut prep school, six of whom have been chosen for the 23-year-long space journey to Terra Two, an Earth-like planet which orbits two suns. There's Harrison Bellgrave, the handsome junior pilot/commander who has an arrogant and violent streak; Poppy Lane, a polyglot from a low-class background who becomes the Comms officer and suffers from depression; twins Juno and Astrid Juma, in training to become a medial officer and astrobiologist- both have eating disorders; Eliot Liston, a robotics specialist in training as an engineer who has mental health issues; Ara Shah, botanist and manic pixie dream girl who is having second thoughts about the mission; and Jesse Solloway, who desperately wants to go but ends up on the reserve replacement crew. One of the hardest things for me to believe is that a crew with so many clashing personality issues would be sent on a mission due to last more than two decades; surely the British Interplanetary Society would have considered the crew's emotional cohesion necessary for mission success? This book has a lot of debut-novel inconsistency: the first 150-200 were engaging but then it heads into a middle section which dragged so much I almost gave up on it. I'm glad I didn't because the last 100 pages were action packed and dramatic, but the 4 star ending only pulls my overall book rating to 3 stars.