SCIENCE FILE: An exploration of issues and trends affecting science, medicine and the environment. : Design Changes in Space Shuttle Cut Failure Risk, Analysis Says
<i> From Times staff and wire reports</i>
Changes in the design of the space shuttle after the 1986 Challenger explosion have reduced the chances of a catastrophic failure from once in every 78 launches to once in every 248, according to a new analysis prepared for NASA by Science Applications International Corp. Among other things, NASA engineers have redesigned the main engines on the orbiter, redesigned rocket nozzle joints and added additional “O” rings to the field joints on the solid-fuel boosters to reduce the chance of hot gas leaks.
Nonetheless, the engines and booster rockets represent 90% of the risk of failure during a launch--with the orbiter engines contributing 63% of the total risk and the boosters the remaining 27%.
