Space junk crashing into Earth is a real and escalating danger. Milne provides the first synthesis of the interdisciplinary work of the scientific community, which has been investigating how the satellite industry can be protected from manmade and natural space hazards. The result is an invaluable book for those concerned with space missions and space disasters, those worried about cosmic radiation and its effects on humans, members of the Spaceguard defense movement, and anyone concerned with defense and international cooperation efforts in general. Tens of millions of objects may exist in space, ranging in size from grains of sand to entire rocket boosters. Many "fireballs" seen in the skies, often thought to be UFOs, are in fact manmade debris. Plutonium and other highly toxic fuels from failed Russian craft have already contaminated inhabited areas of Central Asia. Natural hazards such as comet particles can travel at 100 times the speed of a bullet and can severely damage satellites. There is also the danger of "spaceweather" effects, such as cosmic rays, that could interfere with a spacecraft's electronics and interrupt the global transmission of telephones and television.