NASA Says Shuttle Risk Overstated; Yet Some Risk Unavoidable, Popular Mechanics
"NASA's official overall probability risk assessment number (PRAN) for complete loss of life and vehicle for the Space Shuttle remains at the widely quoted 1/100. Theoretically, there's a one percent chance of catastrophe. While the agency stresses that Space Shuttle flights are extremely dangerous missionssending humans into space always isofficials worry that the risk has been overstated. According to NASA, in practice, it's not as bad as it sounds."