COPY NO. c_ FINAL REPORT DEVELOPMENT OF A WEIGHT/SIZING DESIGN SYNTHESIS COMPUTER PROGRAM 28 FEBRUARY 1973 M D C E0746 VOLUME I PROGRAM FORMULATION SUBMITTED TO NATIONAL AERONAUTICS AND SPACE ADMINISTRATION LYNDON B. JOHNSON SPACE CENTER HOUSTON, T EXAS 77058 CONTRACT NAS 9-12989 _y, • PREPARED M, GARRISON, STUDY MANAGER APPROVED BY: _,_ _P_¢t_ _,_,_J ._r. MORGAN_ANAGERWEIGHTS MCDONNELL DOUGLAS ASTRONAUTICS COMPANY ,, EAST Saint Louis, Missouri 63166 (314) 232-0232 i MCDONNELL DOUGLA__: CORPORATION REPORT MDC E0746 DEVELOPMENT OF A WEIGHT/SIZING DESIGN SYNTHESIS VOLUMEI COMPUTER PROGRAM - FINAL REPORT 28 FEBRUARY 1973 FOREWORD The Weight/Sizing Design Synthesis Computer Program was developed by McDonnell Douglas Astronautics Company - East under Contract NAS 9-12989 for the National Aeronautics and Space Administration, Lyndon B. Johnson Space Center, Houston, Texas. The contract involved a study to derive basic weight estimation relation- ships for those elements of the Space Shuttle vehicle which contribute a signifi- cant portion of the inert weight. These relationships measure the pacing parameters of load, geometry, material, and environment. The weight estimation relationships are then combined into the Weight/Sizing Design Synthesis Computer Program. This report is submitted in three volumes: I Program Formulation II Program Description III User Manual This volume contains the definition of the Weight/Sizing Design Synthesis Computer Program, along with the rationale leading to its development. Included is a listing of the weight scaling models, the physical description of the equations, and supporting weight data. MCDONNELL DOUGLAS ASTROIYAUTICS COMPANY- EAST REPORT MDC E0746 DEVELOPMENT OF A WEIGHT/SIZING DESIGN SYNTHESIS VOLUME I COMPUTER PROGRAM - FINAL REPORT 28 FEBRUARY 1973 ACKNOWLEDGEMENTS The following McDonnell Douglas Astronautics Company , East personnel were the major contributors to the technical contents of this study. L. M. Gnojewski/R. W. Ridenour Program Coding/Assembly Integration B. A. Grob External Tank & Empirical Equations J. J. Morgan Wing J. M. Garrison Structure Models The Technical Monitor for the National Aeronautics and Space Administration, Mr. Norman A. Piercy, of the Engineering Technology Branch, provided valuable guidance and direction throughout the study. iii MCDONNELL DOUGLAS ASTRONAUTICS COMPANY - EAIrr DEVELOPMENT OF A WEIGHT/SIZINGDESIGNSYNTHESIS REPORT MDC E0746 VOLUME I COMPUTERPROGRAM- FINAL REPORT 28 FEBRUARY 1973 TABLE OF CONTENTS Section Title Page i. Introduction ............................ i-i 2. Approach .............................. 2-1 3. Orbiter Module ........................... 3.0-1 3.1 Wing and Tail Torque Box Model ................. '. 3.1-1 3.2 Develop Body Basic Structure Model ................. 3.2-1 3.3 Thermal Protection System Weights ................. 3.3-1 3.4 Landing and Docking Model ..................... 3.4-1 3.5 Propulsion Systems ......................... 3.5-1 3.6 Miscellaneous Systems ....................... 3.6-1 4. External Tanks ........................... 4-1 5. Booster Module ........................... 5-1 6. References ............................. 6-1 APPENDIX .............................. A-I LIST OF PAGES TITLE ii through iv i-i and 1-2 2-1 through 2-17 3.0-i through 3.0-25 3.1-i through 3.1-37 3.2-1 through 3.2-25 3.3-1 through 3.3-47 3.4-1 through 3.4-15 3.5-1 through 3.5-11 3.6-1 through 3.6-4 4-1 through 4-52 5-1 through 5-27 6-1 and 6-2 A-I through A-21 iv MCDONNELL DOUGLAS ASTRONAUTICS COMPANY., EAST REPORT MDCE0746 DEVELOPMENT OF A WEIGHT/SIZINGDESIGNSYNTHESIS VOLUME I COMPUTERPROGRAM- FINAL REPORT 28 FEBRUARY 1973 I. INTRODUCTION The primary objective of thls study was the development of a Weight/Sizing Design Synthesis Methodology to be used in support of the main line Space Shuttle Program. This methodology has a minimum number of data inputs and quick turn around capabilities consistant with the objective of enabling the NASA to rapidly: (a) make weight comparisons between current Shuttle configurations and proposed changes, (b) determine the effects of various subsystems trades on total systems weight, and (c) determine the effects of weight on performance and performance on weight. We have used the technology developed during the Space Shuttle Phase B Program as our starting point, and expanded this technology into a workable family of weight estimation models tailored to the parallel burn Orbiter with an external LOX/LH 2 tank and a solid rocket motor booster. These models permit rapid weight and sizing calculations to be made with sufficient accuracy to measure the load, material, geometry, system configurations, and environmental parameters of interest to the Shuttle Program. The study was organized into six tasks conducted in three distinct steps. The first step was to identify and deliver baseline programs (Task l),and to review existing technology to identify each equation and to scope the effort required to develop each element (Task 2). Our starting point was the existing CASPER (C_onfiguration _Analysis, Sizing and PERformance) progra_developed for a fully reusable Space Shuttl_ and APSE (_Analytical Parametric S_ystem E__valuation), which is an expanded version of CASPER, capable of multiple vehicle baseline configurations, and the VSP _ehicle S_ensltlvlties Program), developed to provide vehicle sensitivities. These baseline programs, along with informal user guides, were delivered to the NASA at the initial review on 30-31 August 1972. The second step of this study, Tasks 3, 4, and 5,was to develop the required weight/sizing equations. We concentrated our efforts on those elements which contribute a significant fraction of the inert weight, and have a significant inter- face with the major load, material, and configuration parameters of the Shuttle. We identified these key elements as the wing and tail torque box, the body basic structure, the landing gear structure, the external tank, and the propulsion system inerts. The models for these key elements are developed (Task 3) from analytical relationships to a level consistent with overall input data requirements and required output accuracy. The remaining elements, such as the 1-I MCDOnnELL DOU_L_8 ASTRONAUTICS COMPANY " EAHT REPORT MDCE0746 DEVELOPMENT OF A WEIGHT/SIZING DESIGN SYNTHESIS VOLUMEI COMPUTER PROGRAM - FINAL REPORT 28 FEBRUARY 1973 Thermal Protection System, Controls, Power, and Avionics, are represented by empirical relationships developed (Task 4) from existing models, hardware data, or Shuttle study data. Accuracy is demonstrated (Task 5) at both system and subsystem levels. The third step, Task 6, refined the logic of the baseline APSE program, and oriented it to the current configuration of an external tank orbiter with a solid rocket motor booster. Additional work consisted of incorporating the developed equation into the refined program and installing it on the J$C UNIVAC 1108 computer. The results of this study will provide the NASA with a weight/sizing computer program that: (a) can analyze the current configuration and ongoing efforts, (b) provides various vehicle sizing options, including size to payload, size to gross weight, and size to critical mission. The program will compute delta payload or delta performance with provision for constant thrust or T/W ratios, and (c) provide gross weight sensitivity to various system parameters, including payload weights and volumes, on orbit AV, system inert weights, Isp , and thrust level. ]-2 MCDONNELL DOUGLAS ASTROItlAUTICS COMPANY - EAS"r REPORT MDC E0746 DEVELOPMENT OF A WEIGHT/SIZING DESIGN SYNTHESIS VOLUME I COMPUTER PROGRAM - FINAL REPORT 28 FEBRUARY 1973 2. APPROACH Step i, encompassing Task i, Identify and Deliver Baseline Programs, and Task 2, Review Existing Technology to Identify Each Equation and Scope the Effort Required to Develop Each Element, was utilized as the basis for formu- lating the Weight/Sizing Design Synthesis Computer Program. This step defined our starting point and depicted our anticipated results. Step 2, including Task 3, Development of Analytical Models for Key Elements, Task 4, Refinement of Empirical Models for Remaining Elements, and Task 5, Weight Model Accuracy, derived the weight-estimation models to be used in defining the orbiter, booster, and external tank modules. Step 3 is essentially the culmination of the study. This step (Task 6) formulates the Weight/Sizing Design Synthesis Computer Program. This is the E__xecutive Sizing PERformance (ESPER) program. The ESPER program is a multioption sizing/synthesis program geared to the Solid Rocket Motor (SRM) Booster in parallel with an external hydrogen/oxygen tank orbiter for either the easterly (28-1/2 deg inclination) polar (90 deg inclination), or resupply (55 deg inclination) missions. The program has two primary options: (a) fixed hardware, and (b) iterative vehicle sizing. The fixed hardware option determines the payload capability of a given configuration. This allows the user to determine the effect on performance of configuration and/or criteria changes, either real or proposed. The iterative vehicle sizing option physically sizes the vehicles for a given payload. It determines the size of the SRM and its propellant load, and the size of the external tank and its corresponding propellant load. The iterative procedure is based on either the sizing criteria of a fixed staging velocity or it will size the vehicle to a minimum gross lift off weight (GLOW). The minimum GLOW option is provided as