Methods and techniques for risk prediction of Space Shuttle upgrades

AIAA-98-1938METHODS AND TECHNIQUES FOR RISK PREDICTION OF SPACE SHUTTLE UPGRADESChad R. Hoffman & Rich PughPratt & WhitneyWest Palm Beach, FLAbstractSince the Space Shuttle Accident in 1986, NASAhas been trying to incorporate probabilistic riskassessment (PRA) in decisions concerning theSpace Shuttle and other NASA projects. Onemajor study NASA is currently conducting is in thePRA area in establishing an overall risk model forthe Space Shuttle System. The model is intendedto provide a tool to predict the Shuttle risk and toperform sensitivity analyses and trade studiesincluding evaluation of upgrades. Marshall SpaceFlight Center (MSFC) and its prime contractorsincluding Pratt and Whitney (P&W) are part of theNASA team conducting the PRA study. MSFCresponsibility involves modeling the External Tank(ET), the Solid Rocket Booster (SRB), theReusable Solid Rocket Motor (RSRM), and theSpace Shuttle Main Engine (SSME). A majorchallenge that faced the PRA team is modeling theshuttle upgrades. This mainly includes the P&WHigh Pressure Fuel Turbopump (HPFTP) and theHigh Pressure Oxidizer Turbopump (HPOTP).The purpose of this paper is to discuss the variousmethods and techniques used for predicting therisk of the P&W redesigned HPFTP and HPOTP.Fayssal Safie t ,," _-_ -",/.," 'NASAJMSFCHuntsville, AL /, . <-.,.#