Natural elements and cosmic phenomena in space, such as asteroids, comets, meteors, black holes and super bubbles pose a threat to the planet Earth and spacefarers in the near-Earth environment. describes these dangers in the near-Earth outer space environment. The uniquely risky nature of rocket transportation is documented and quantified. The human health consequences for vision, muscles, and the neurovestibular system, for instance, on exposure to an outer space environment, are also explained in this book. Readers will benefit from the extensive information offered within this text which is also accompanied with a bibliography of references. This book offers a comprehensive primer for anyone interested in space travel and associated risk assessment.