Book excerpt: As Space X works to reduce the barriers of access to space and Virgin Galactic forges a path to commercial spaceflight for the masses, we have begun to cross the realms of science fiction into the reality of humans viewing the cosmos with their own eyes. Part of an internationally bestselling series, 30-Second Space Travel sees a team of expert astronomers hand-pick the 50 most exciting topics and essential concepts in the field of space exploration and break down each subject into an easily accessible summary that takes just half a minute to understand. Beginning with Galileo and the early telescope explorers of the Renaissance, via the physics of orbital mechanics and the Apollo and Sputnik missions of the Space Race, and on to a future of space tourism and planetary colonisation, this book will open up a whole universe of space travel and leave you eager to research the field in more depth.