Since 1961 more than eighty satellite fragmentation events have been identified. These occurrences are responsible for one-third of all man-made space objects cataloged since Sputnik 1 and constitute one-half of all satellites currently in orbit about the Earth. The two known mechanisms of artificial satellite break-ups are accidental (e.g. propulsion-related malfunctions) and deliberate (e.g. military-related activities) on-board explosions. However, the causes of half of all satellite break-ups remain undetermined. The steady increase in the near-Earth space debris population raises legitimate concerns about the mounting probability of satellite-satellite collisions. The limitations of ground-based radars suggest that the true population of Earth-orbiting satellites may be many times that officially registered. Recent laboratory tests indicate that a large number of potentially lethal fragments would be liberated during a hypervelocity collision in space.