Propellant Densification for Shuttle: The SSME Perspective

AIAA 2002-3602Propellant Densification for Shuttle: The SSME PerspectiveWilliam D. Greene and Dayna L. BoxxNASA Marshall Space Flight Center, Huntsville, ALAbstractThe subject of cryogenic propellant densification as a potential upgrade to the Space Shuttle is asubject that has been raised on several occasions over the last decade. Due to advancements indensification technology made as a part of and in parallel to the X-33 project, the subject wasraised and studied once again in May 2001. Across the Space Shuttle program people frommany disciplines converged to discuss issues and perform trade studies to determine whetherdensified propellants was worth pursuing. This paper discusses one of these areas, specificallythe Space Shuttle Main Engine (SSME). The effects of propellant densification on steady stateperformance are presented along with discussions of potential transient performance issues.Engine component redesign and retrofit issues are discussed as well the high level requirementsto modify the ground test stands to accommodate propellant densification hardware and tanks.And finally, the matter of programmatic concerns enters the subject at band as part of adiscussion of SSME recertification requirements. In the end, potential benefits to SSMEperformance can be demonstrated and, subject to the densification scheme chosen, there does notappear to insurmountable technical obstacles.NomenclatureSymbolsIsp Specific impulserh Mass flow rateAP Pressure dropP Fluid densityR Flow resistanceR Degrees Rankine/a ViscosityAcron ¥msDLH2 Densified LH2DLO2 Densified LO2