IUS (Inertial Upper Stage)/SRM-2 Nozzle Thermal Assessment
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HUNTSVILLE AL GEORGE C MARSHALL SPACE FLIGHT CENTER
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During the space shuttle mission STS-6 on April 5, 1983, the inertial upper stagetracking data relay satellite-A payload experienced a loss of control at approximately 85 seconds into the planned 105 second burn of the second stage. The anomaly was reviewed by several teams, indicating the most probable cause to be the Techroll Seal TRS resulting in loss of the silicon fluid bearing surface required for nozzle vectoring. Detailed TPS failure scenarios were investigated that would allow hot combustion gases to overheat the titanium TRS housing. Two areas were found in the nozzle TPS design where this could occur 1 The nose cap carbon phenolic to silica phenolic bond surface where temperatures were predicted to exceed the bonding material limit and 2 the grafoil sealexit cone joint area where leakage of the grafoil seal would allow hot combustion gases diffused from the integral throat entrance 3-D carbon-carbon material to impinge onto the titanium housing. This paper deals principally with the second area and describes design enhancements which were added to the existing IUS motor.
- Solid Propellant Rocket Engines
- Adhesives, Seals and Binders