This is a fascinating little book, explaining a lot of very complex ideas in clear, understandable text.  After a brief explanation of the history of exploration, it goes on to describe the many challenges that must be tackled to achieve interstellar exploration within the next 100 years.  The team that has gathered to study this possibility includes scientists, engineers, doctors, businesspeople, etc. The book manages to make clear just how difficult such a prospect, while still inspiring confidence and hope that it will be achieved someday.  My only gripe with the book is something I’ve been noticing in a lot of non-fiction lately: a “timeline” that really isn’t a proper timeline at all, but just a list of dates of significant events.