Flight Motor Set 360T010 (STS-31R). Volume 1: System Overview

Flight motor set 360T010 was launched at approximately 7:34 a.m. CST (090:114:12:33:50.990 GMT) on 24 Apr. 1990 after one launch attempt (attempt on 10 Apr. 1990 was scrubbed following an indication of erratic operation of the Orbiter No. 1 Auciliary Power Unit No. 1). There were no problems with the solid rocket motor launches, overall motor performance was excellent. There were no debris concerns from either motor. Nearly all ballistic contract end item specification parameters were verified with the exception of ignition interval, pressure rise rate, and ignition time thrust imbalance. These could not be verified due to elimination of developmental flight instrumentation on 360L004 (STS-30R) and subsequent, but low sample rate data that were available showed nominal propulsion performance. All ballistic and mass property parameters that could be assessed closely matched the predicted values and were well within the required contract end item specification levels. All field joint heaters and igniter joint heaters performed without anomalies. Evaluation of the ground environment instrumentation measurements again verified thermal model analysis data and showed agreement with predicted environmental effects. No launch commit criteria violations occurred. Postflight inspection again verified nominal performance of the insulation, phenolics, metal parts, and seals. Postflight evaluation indicated both nozzles performed as expected during flight. All combustion gas was contained by insulation in the field and case-to-nozzle joints.