scope:

Description of Driving Event:

The primary reason for the use of the putty in the SRM was to act as a thermal barrier in the joints to prevent o-ring erosion resulting from circumferential hot gas flow during motor firing. Prior to the 51-L mishap, the putty was believed to perform such that it would allow pressure to the primary oring during the SRM ignition transient. Subsequently, it has been found that humidity and temperature enhance the characteristics of putty relative to its pressure holding characteristics. The uncertainty of these characteristic changes directly affected the ability of the field joint to seal.