Planning for the Future

摘要

The shuttle-orbiter system has served the U.S. space program well. The demonstrated reliability of 98 percent to 99 percent would be excellent for most launch vehicles, but it is unfortunately not good enough for manned vehicles that, do not include a crew escape opportunity during the most, dangerous portions of the flight. We should be confident that improved safety provisions have and will result from the redesign and modifications to the shuttle fleet that followed the Challenger and Columbia tragedies. Yet, any further analytical calculation tor catastrophic failure probability as a fact, should be highly suspect. We will have to provide launch crews with a "pad abort" capability in future vehicles, regardless of our estimated failure rate. The American public and our elected representatives in Congress will accept no less.