Space shuttle development Motor No. 9 (DM-9), volume 1

The results obtained during the December 23, 1987 static firing of the DM-9 test article are presented. The DM-9 full-scale static test article employed redesigned solid rocket motor (RSRM) field joint capture feature hardware with J-seal insulation configuration, and nozzle-to-case joint radial bolt design with bonded insulation configuration. The nozzle incorporated RSRM components, including a thicker cowl with involuted outer boot ring. The nozzle employed redundant and verifiable seals in all five joints, and room temperature vulcanization backfill in three joints. With very few exceptions, the DM-9 test article was flight configuration. The test was conducted under extreme weather conditions: temperature of 25 F and wind at 15 to 20 mph. Ballistics performance values were within specification requirements. The RSRM field joint (J-seal) insulation configuration functioned as predicted with no indication of hot gases reaching the capture feature O-rings. There was a blowhole in the polysulfide adhesive in the nozzle-to-case joint, but no evidence of hot gases past the wiper O-ring. Nozzle design changes appeared to perform nominally, with the exception of the outer boot ring, which suffered partial structural breakup late in the test. Field joint heaters maintained the controlling resistance temperature device temperature within the specified requirements during heater operation. The thrust vector control system operated properly. The redesigned water deluge system, temperature conditioning equipment, and other test support equipment performed as planned.