Technology Development: Concepts, Requirements And Assessment Overview

AIAA 2002-0502METALLIC THERMAL PROTECTION SYSTEM TECHNOLOGY DEVELOPMENT:CONCEPTS, REQUIREMENTS AND ASSESSMENT OVERVIEWJohn T. Dorsey*, Carl C. Potee(, Roger R. Chen**, and Kathryn E. Wurster _NASA Langley Research CenterHampton, VAABSTRACTA technology development program wasconducted to evolve an earlier metallic thermalprotection system (TPS) panel design, with the goalsof: improving operations features, increasingadaptability (ease of attaching to a variety of tankshapes and structural concepts), and reducing weight.The resulting Adaptable Robust Metallic OperableReusable (ARMOR) TPS system incorporates a highdegree of design flexibility (allowing weight andoperability to be traded and balanced) and can also beeasily integrated with a large variety of tank shapes,airframe structural arrangements and airframestructure/material concepts. An initial attempt hasbeen made to establish a set of performance basedTPS design requirements. A set of general (FAR-type) requirements have been proposed, focusing ondefining categories that must be included for acomprehensive design. Load cases required for TPSdesign must reflect the full flight envelope, includinga comprehensive set of limit loads. However,including additional loads, such as ascent aborttrajectories, as ultimate load cases, and on-orbitdebris/micro-meteoroid hypervelocity impact, as oneof the discrete-source-damage load cases, will have asignificant impact on system design and resultingperformance, reliability and operability. Although*Senior Research Engineer, Metals" and ThermalStructures Branch, Mail Stop 396, Senior MemberAIAA.Research Engineer, Metals and Thermal StructuresBranch, Mail Stop 396._"Aeronautical Engineer, Lockheed Martin SpaceOperations._Senior Research Engineer, Vehicle Analysis Branch,Mail Stop 365. Associate Fellow AIAA.Copyright© 2002 by the American Institute of Aeronauticsand Astronautics, Inc. No copyright is asserted in theUnited States under Title 17, U.S. Code. The U.S.Government has a royalty-free license to exercise all rightsunder the copyright claimed herein for Governmentalpurposes. All other rights are reserved by the copyrightowner.these load cases have not been established, they areof paramount importance for reusable vehicles, anduntil properly included, all sizing results andassessments of reliability and operability must beconsidered optimistic at a minimum.INTRODUCTIONOne of the major goals of NASA has been todevelop enabling technology for future launchvehicles. The emphasis has been on a vehicle thatwould bc lightweight, fully reusable and easilymaintained under the assumption that such a vehiclewould achieve low-cost access to space. Theproposed Lockheed-Martin VentureStar