This concise yet comprehensive treatment of the effects of spaceflight on biological systems includes issues at the forefront of life sciences research, such as gravitational biology, immune system response, bone cell formation and the effects of radiation on biosystems. Edited by a leading specialist at the European Space Agency (ESA) with contributions by internationally renowned experts, the chapters are based on the latest space laboratory experiments, including those on SPACELAB, ISS, parabolic flights and unmanned research satellites. An indispensable source for biologists, medical researchers and astronautics experts alike. The results of Space flight experiments, ground controls and flight simulations pave the way for a better understanding of gravity reactions in various organisms down to molecular mechanisms. This publication marks also the beginning of a new Space flight era with the construction and exploitation of the International Space Station (ISS) which provides a platform for an in-depth continuation of experiments under weightlessness in Low Earth Orbit and beyond.