Disaster Blamed on O-Rings, Pressure to Launch

The commission's specific recommendations are:

*Eliminate or redesign the joint. A panel of the National Research Council should oversee the effort. NASA is already doing this.

*Reorganize the shuttle program so managers are accountable to the overall program rather than their individual NASA centers, and include more astronauts in management.

*Review the shuttle's most critical parts to see that they are as safe as possible, and have the findings verified by an independent panel of the National Research Council.

*Create a larger, more powerful Office of Safety, Reliability and Quality Assurance, headed by an associate administrator who reports directly to the NASA administrator.

*Improve communications between Marshall and other NASA centers and keep better records of flight readiness meetings.

*Improve tires, brakes and steering systems critical to landing safety. Land only at Edwards Air Force Base until improvements are made.

*Reexamine whether to provide means of crew escape once the orbiter is free of solid rockets. (Escape before this point is not feasible.)

*Establish a rigorous system for maintaining highly critical shuttle parts and have enough spare parts to stop cannibalizing one orbiter to supply another.

The commission urged that NASA report to the president in a year on its progress in fulfilling the recommendations.

Perhaps the most damning chapter in the report deals with the history of the booster's joint design. Under the heading "An Accident Rooted in History," the chapter shows that the Challenger disaster could be seen coming as far back as 1977, four years before the first shuttle flight.

Engineers at Marshall were evaluating early laboratory tests of the joints that showed that the gap opened when subjected to pressure, the opposite of what Thiokol designers assumed. Thiokol disputed the findings.