Engineering evaluation of SSME dynamic data from engine tests and SSV flights

NASA Technical Reports Server (NTRS)

1986-01-01

An engineering evaluation of dynamic data from SSME hot firing tests and SSV flights is summarized. The basic objective of the study is to provide analyses of vibration, strain and dynamic pressure measurements in support of MSFC performance and reliability improvement programs. A brief description of the SSME test program is given and a typical test evaluation cycle reviewed. Data banks generated to characterize SSME component dynamic characteristics are described and statistical analyses performed on these data base measurements are discussed. Analytical models applied to define the dynamic behavior of SSME components (such as turbopump bearing elements and the flight accelerometer safety cut-off system) are also summarized. Appendices are included to illustrate some typical tasks performed under this study.

STS-40 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1991-01-01

The STS-40 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-first flight of the Space Shuttle and the eleventh flight of the Orbiter Vehicle Columbia (OV-102). In addition to the Columbia vehicle, the flight vehicle consisted of an External Tank (ET) designated as ET-41 (LWT-34), three Space Shuttle main engines (SSME's) (serial numbers 2015, 2022, and 2027 in positions 1, 2, and 3, respectively), and two Solid Rocket Boosters (SRB's) designated as BI-044. The primary objective of the STS-40 flight was to successfully perform the planned operations of the Spacelab Life Sciences-1 (SLS-1) payload. The secondary objectives of this flight were to perform the operations required by the Getaway Special (GAS) payloads and the Middeck O-Gravity Dynamics Experiment (MODE) payload.

STS-40 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W.

1991-07-01

The STS-40 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-first flight of the Space Shuttle and the eleventh flight of the Orbiter Vehicle Columbia (OV-102). In addition to the Columbia vehicle, the flight vehicle consisted of an External Tank (ET) designated as ET-41 (LWT-34), three Space Shuttle main engines (SSME's) (serial numbers 2015, 2022, and 2027 in positions 1, 2, and 3, respectively), and two Solid Rocket Boosters (SRB's) designated as BI-044. The primary objective of the STS-40 flight was to successfully perform the planned operations of the Spacelab Life Sciences-1 (SLS-1) payload. The secondary objectives of this flight were to perform the operations required by the Getaway Special (GAS) payloads and the Middeck O-Gravity Dynamics Experiment (MODE) payload.

STS-38 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Camp, David W.; Germany, D. M.; Nicholson, Leonard S.

1991-01-01

The STS-38 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-seventh flight of the Space Shuttle and the seventh flight of the Orbiter vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-40/LWT-33), three Space Shuttle main engines (SSME's) (serial numbers 2019, 2022, 2027), and two Solid Rocket Boosters (SRB's), designated as BI-039. The STS-38 mission was a classified Department of Defense mission, and as much, the classified portions of the mission are not presented in this report. The sequence of events for this mission is shown. The significant problems that occurred in the Space Shuttle Orbiter subsystem during the mission are summarized and the official problem tracking list is presented. In addition, each Space Shuttle Orbiter problem is cited in the subsystem discussion.

STS-36 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Mechelay, Joseph E.; Germany, D. M.; Nicholson, Leonard S.

1990-01-01

The STS-36 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-fourth flight of the Space Shuttle and the sixth flight of the OV-104 Orbiter vehicle, Atlantis. In addition to the Atlantis vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-33/LWT-26), three Space Shuttle main engines (SSME's) (serial numbers 2019, 2030, and 2029), and two Solid Rocket Boosters (SRB's) (designated as BI-036). The STS-36 mission was a classified Department of Defense mission, and as such, the classified portions of the mission are not discussed. The unclassified sequence of events for this mission is shown in tabular form. Summarized are the significant problems that occurred in the Orbiter subsystems during the mission. The official problem tracking list is presented. In addition, each of the Orbiter problems is cited in the subsystem discussion.

STS-41 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Camp, David W.; Germany, D. M.; Nicholson, Leonard S.

1990-01-01

The STS-41 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-sixth flight of the Space Shuttle and the eleventh flight of the Orbiter vehicle, Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-39/LWT-32), three Space Shuttle main engines (SSME's) (serial numbers 2011, 2031, and 2107), and two Solid Rocket Boosters (SRB's), designated as BI-040. The primary objective of the STS-41 mission was to successfully deploy the Ulysses/inertial upper stage (IUS)/payload assist module (PAM-S) spacecraft. The secondary objectives were to perform all operations necessary to support the requirements of the Shuttle Backscatter Ultraviolet (SSBUV) Spectrometer, Solid Surface Combustion Experiment (SSCE), Space Life Sciences Training Program Chromosome and Plant Cell Division in Space (CHROMEX), Voice Command System (VCS), Physiological Systems Experiment (PSE), Radiation Monitoring Experiment - 3 (RME-3), Investigations into Polymer Membrane Processing (IPMP), Air Force Maui Optical Calibration Test (AMOS), and Intelsat Solar Array Coupon (ISAC) payloads. The sequence of events for this mission is shown in tabular form. Summarized are the significant problems that occurred in the Orbiter subsystems during the mission. The official problem tracking list is presented. In addition, each Orbiter problem is cited in the subsystem discussion.

STS-39 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1991-01-01

The STS-39 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the fortieth flight of the Space Shuttle and the twelfth flight of the Orbiter Vehicle Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of the following: an External Tank (ET) (designated as ET-46 (LWT-39); three Space Shuttle main engines (SSME's) (serial numbers 2026, 2030, and 2029 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-043. The primary objective of this flight was to successfully perform the planned operations of the Infrared Background Signature Survey (IBSS), Air Force Payload (AFP)-675, Space Test Payload (STP)-1, and the Multipurpose Experiment Canister (MPEC) payloads.

STS-39 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W.

1991-06-01

The STS-39 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the fortieth flight of the Space Shuttle and the twelfth flight of the Orbiter Vehicle Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of the following: an External Tank (ET) (designated as ET-46 (LWT-39); three Space Shuttle main engines (SSME's) (serial numbers 2026, 2030, and 2029 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-043. The primary objective of this flight was to successfully perform the planned operations of the Infrared Background Signature Survey (IBSS), Air Force Payload (AFP)-675, Space Test Payload (STP)-1, and the Multipurpose Experiment Canister (MPEC) payloads.

Characterization of real gas properties for space shuttle main engine fuel turbine and performance calculations

NASA Technical Reports Server (NTRS)

Harloff, G. J.

1986-01-01

Real thermodynamic and transport properties of hydrogen, steam, the SSME mixture, and air are developed. The SSME mixture properties are needed for the analysis of the space shuttle main engine fuel turbine. The mixture conditions for the gases, except air, are presented graphically over a temperature range from 800 to 1200 K, and a pressure range from 1 to 500 atm. Air properties are given over a temperature range of 320 to 500 K, which are within the bounds of the thermodynamics programs used, in order to provide mixture data which is more easily checked (than H2/H2O). The real gas property variation of the SSME mixture is quantified. Polynomial expressions, needed for future computer analysis, for viscosity, Prandtl number, and thermal conductivity are given for the H2/H2O SSME fuel turbine mixture at a pressure of 305 atm over a range of temperatures from 950 to 1140 K. These conditions are representative of the SSME turbine operation. Performance calculations are presented for the space shuttle main engine (SSME) fuel turbine. The calculations use the air equivalent concept. Progress towards obtaining the capability to evaluate the performance of the SSME fuel turbine, with the H2/H2O mixture, is described.

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystem Concepts. Volume 1; Executive Summary

NASA Technical Reports Server (NTRS)

Levack, Daniel J. H.

2000-01-01

The Alternate Propulsion Subsystem Concepts contract had seven tasks defined that are reported under this contract deliverable. The tasks were: FAA Restart Study, J-2S Restart Study, Propulsion Database Development. SSME Upper Stage Use. CERs for Liquid Propellant Rocket Engines. Advanced Low Cost Engines, and Tripropellant Comparison Study. The two restart studies, F-1A and J-2S, generated program plans for restarting production of each engine. Special emphasis was placed on determining changes to individual parts due to obsolete materials, changes in OSHA and environmental concerns, new processes available, and any configuration changes to the engines. The Propulsion Database Development task developed a database structure and format which is easy to use and modify while also being comprehensive in the level of detail available. The database structure included extensive engine information and allows for parametric data generation for conceptual engine concepts. The SSME Upper Stage Use task examined the changes needed or desirable to use the SSME as an upper stage engine both in a second stage and in a translunar injection stage. The CERs for Liquid Engines task developed qualitative parametric cost estimating relationships at the engine and major subassembly level for estimating development and production costs of chemical propulsion liquid rocket engines. The Advanced Low Cost Engines task examined propulsion systems for SSTO applications including engine concept definition, mission analysis. trade studies. operating point selection, turbomachinery alternatives, life cycle cost, weight definition. and point design conceptual drawings and component design. The task concentrated on bipropellant engines, but also examined tripropellant engines. The Tripropellant Comparison Study task provided an unambiguous comparison among various tripropellant implementation approaches and cycle choices, and then compared them to similarly designed bipropellant engines in the SSTO mission This volume overviews each of the tasks giving its objectives, main results. and conclusions. More detailed Final Task Reports are available on each individual task.

Independent Orbiter Assessment (IOA): Assessment of the orbiter main propulsion system FMEA/CIL, volume 1

NASA Technical Reports Server (NTRS)

Slaughter, B. C.

1988-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Main Propulsion System (MPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to available data from the Rockwell Downey/NASA JSC FMEA/CIL review. The Orbiter MPS is composed of the Propellant Management Subsystem (PMS) consisting of the liquid oxygen (LO2) and liquid hydrogen (LH2) subsystems and the helium subsystem. The PMS is a system of manifolds, distribution lines, and valves by which the liquid propellants pass from the External Tank to the Space Shuttle Main Engine (SSME). The helium subsystem consists of a series of helium supply tanks and their associated regulators, control valves, and distribution lines. Volume 1 contains the MPS description, assessment results, ground rules and assumptions, and some of the IOA worksheets.

The cost of performance - A comparison of the space transportation main engine and the Space Shuttle main engine

NASA Technical Reports Server (NTRS)

Barisa, B. B.; Flinchbaugh, G. D.; Zachary, A. T.

1989-01-01

This paper compares the cost of the Space Shuttle Main Engine (SSME) and the Space Transportation Main Engine (STME) proposed by the Advanced Launch System Program. A brief description of the SSME and STME engines is presented, followed by a comparison of these engines that illustrates the impact of focusing on acceptable performance at minimum cost (as for the STME) or on maximum performance (as for the SSME). Several examples of cost reduction methods are presented.

SSME Investment in Turbomachinery Inducer Impeller Design Tools and Methodology

NASA Technical Reports Server (NTRS)

Zoladz, Thomas; Mitchell, William; Lunde, Kevin

2010-01-01

Within the rocket engine industry, SSME turbomachines are the de facto standards of success with regard to meeting aggressive performance requirements under challenging operational environments. Over the Shuttle era, SSME has invested heavily in our national inducer impeller design infrastructure. While both low and high pressure turbopump failures/anomaly resolution efforts spurred some of these investments, the SSME program was a major benefactor of key areas of turbomachinery inducer-impeller research outside of flight manifest pressures. Over the past several decades, key turbopump internal environments have been interrogated via highly instrumented hot-fire and cold-flow testing. Likewise, SSME has sponsored the advancement of time accurate and cavitating inducer impeller computation fluid dynamics (CFD) tools. These investments together have led to a better understanding of the complex internal flow fields within aggressive high performing inducers and impellers. New design tools and methodologies have evolved which intend to provide confident blade designs which strike an appropriate balance between performance and self induced load management.

Advanced transportation system studies technical area 3: Alternate propulsion subsystem concepts, volume 3

NASA Technical Reports Server (NTRS)

Levak, Daniel

1993-01-01

The objective of this contract was to provide definition of alternate propulsion systems for both earth-to-orbit (ETO) and in-space vehicles (upper stages and space transfer vehicles). For such propulsion systems, technical data to describe performance, weight, dimensions, etc. was provided along with programmatic information such as cost, schedule, needed facilities, etc. Advanced technology and advanced development needs were determined and provided. This volume separately presents the various program cost estimates that were generated under three tasks: the F-1A Restart Task, the J-2S Restart Task, and the SSME Upper Stage Use Task. The conclusions, technical results, and the program cost estimates are described in more detail in Volume 1 - Executive Summary and in individual Final Task Reports.

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystems Concepts. Volume 3; Program Cost Estimates

NASA Technical Reports Server (NTRS)

Levack, Daniel J. H.

2000-01-01

The objective of this contract was to provide definition of alternate propulsion systems for both earth-to-orbit (ETO) and in-space vehicles (upper stages and space transfer vehicles). For such propulsion systems, technical data to describe performance, weight, dimensions, etc. was provided along with programmatic information such as cost, schedule, needed facilities, etc. Advanced technology and advanced development needs were determined and provided. This volume separately presents the various program cost estimates that were generated under three tasks: the F- IA Restart Task, the J-2S Restart Task, and the SSME Upper Stage Use Task. The conclusions, technical results , and the program cost estimates are described in more detail in Volume I - Executive Summary and in individual Final Task Reports.

Evaluation of undeveloped rocket engine cycle applications to advanced transportation

NASA Technical Reports Server (NTRS)

1990-01-01

Undeveloped pump-fed, liquid propellant rocket engine cycles were assessed and evaluated for application to Next Manned Transportation System (NMTS) vehicles, which would include the evolving Space Transportation System (STS Evolution), the Personnel Launch System (PLS), and the Advanced Manned Launch System (AMLS). Undeveloped engine cycles selected for further analysis had potential for increased reliability, more maintainability, reduced cost, and improved (or possibly level) performance when compared to the existing SSME and proposed STME engines. The split expander (SX) cycle, the full flow staged combustion (FFSC) cycle, and a hybrid version of the FFSC, which has a LOX expander drive for the LOX pump, were selected for definition and analysis. Technology requirements and issues were identified and analyses of vehicle systems weight deltas using the SX and FFSC cycles in AMLS vehicles were performed. A strawman schedule and cost estimate for FFSC subsystem technology developments and integrated engine system demonstration was also provided.

STS-31 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Camp, David W.; Germany, D. M.; Nicholson, Leonard S.

1990-01-01

The STS-31 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities on this thirty-fifth flight of the Space Shuttle and the tenth flight of the Orbiter Vehicle Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of an External Tank (ET) (designated as ET-34/LWT-27), three Space Shuttle main engines (SSME's) (serial numbers 2011, 2031, and 2107), and two Solid Rocket Booster (SRB) (designated as BI-037). The primary objective of the mission was to place the Hubble Space Telescope (HST) into a 330 nmi. circular orbit having an inclination of 28.45 degrees. The secondary objectives were to perform all operations necessary to support the requirements of the Protein Crystal Growth (PCG), Investigations into Polymer Membrane Processing (IPMP), Radiation Monitoring Equipment (RME), Ascent Particle Monitor (APM), IMAX Cargo Bay Camera (ICBC), Air Force Maui Optical Site Calibration Test (AMOS), IMAX Crew Compartment Camera, and Ion Arc payloads. In addition, 12 development test objectives (DTO's) and 10 detailed supplementary objectives (DSO's) were assigned to the flight. The sequence of events for this mission is shown. The significant problems that occurred in the Space Shuttle Orbiter subsystems during the mission are summarized, and the official problem tracking list is presented. In addition, each of the Space Shuttle Orbiter problems is cited in the subsystem discussion.

STS-43 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1991-01-01

The STS-43 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-second flight of the Space Shuttle Program and the ninth flight of the Orbiter Vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-47 (LWT-40); three Space Shuttle main engines (SSME's) (serial numbers 2024, 2012, and 2028 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-045. The primary objective of the STS-43 mission was to successfully deploy the Tracking and Data Relay Satellite-E/Inertial Upper Stage (TDRS-E/IUS) satellite and to perform all operations necessary to support the requirements of the Shuttle Solar Backscatter Ultraviolet (SSBUV) payload and the Space Station Heat Pipe Advanced Radiator Element (SHARE-2).

Restricted Complexity Framework for Nonlinear Adaptive Control in Complex Systems

NASA Astrophysics Data System (ADS)

Williams, Rube B.

2004-02-01

Control law adaptation that includes implicit or explicit adaptive state estimation, can be a fundamental underpinning for the success of intelligent control in complex systems, particularly during subsystem failures, where vital system states and parameters can be impractical or impossible to measure directly. A practical algorithm is proposed for adaptive state filtering and control in nonlinear dynamic systems when the state equations are unknown or are too complex to model analytically. The state equations and inverse plant model are approximated by using neural networks. A framework for a neural network based nonlinear dynamic inversion control law is proposed, as an extrapolation of prior developed restricted complexity methodology used to formulate the adaptive state filter. Examples of adaptive filter performance are presented for an SSME simulation with high pressure turbine failure to support extrapolations to adaptive control problems.

STS-43 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W.

1991-09-01

The STS-43 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-second flight of the Space Shuttle Program and the ninth flight of the Orbiter Vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-47 (LWT-40); three Space Shuttle main engines (SSME's) (serial numbers 2024, 2012, and 2028 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-045. The primary objective of the STS-43 mission was to successfully deploy the Tracking and Data Relay Satellite-E/Inertial Upper Stage (TDRS-E/IUS) satellite and to perform all operations necessary to support the requirements of the Shuttle Solar Backscatter Ultraviolet (SSBUV) payload and the Space Station Heat Pipe Advanced Radiator Element (SHARE-2).

Flowfield visualization for SSME hot gas manifold

NASA Technical Reports Server (NTRS)

Roger, Robert P.

1988-01-01

The objective of this research, as defined by NASA-Marshall Space Flight Center, was two-fold: (1) to numerically simulate viscous subsonic flow in a proposed elliptical two-duct version of the fuel side Hot Gas Manifold (HGM) for the Space Shuttle Main Engine (SSME), and (2) to provide analytical support for SSME related numerical computational experiments, being performed by the Computational Fluid Dynamics staff in the Aerophysics Division of the Structures and Dynamics Laboratory at NASA-MSFC. Numerical results of HGM were calculations to complement both water flow visualization experiments and air flow visualization experiments and air experiments in two-duct geometries performed at NASA-MSFC and Rocketdyne. In addition, code modification and improvement efforts were to strengthen the CFD capabilities of NASA-MSFC for producing reliable predictions of flow environments within the SSME.

SSME propellant path leak detection real-time

NASA Technical Reports Server (NTRS)

Crawford, R. A.; Smith, L. M.

1994-01-01

Included are four documents that outline the technical aspects of the research performed on NASA Grant NAG8-140: 'A System for Sequential Step Detection with Application to Video Image Processing'; 'Leak Detection from the SSME Using Sequential Image Processing'; 'Digital Image Processor Specifications for Real-Time SSME Leak Detection'; and 'A Color Change Detection System for Video Signals with Applications to Spectral Analysis of Rocket Engine Plumes'.

A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix B: Data base plots for SSME tests 901-290 through 901-414

NASA Technical Reports Server (NTRS)

Coffin, T.

1986-01-01

A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is described. The data base represents dynamic pressure measurements obtained during single engine hot firing tesets of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is also included to estimate spectral trends with SSME power level. Flow dynamic environments in high performance rocket engines are discussed.

A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix C: Data base plots for SSME tests 902-214 through 902-314

NASA Technical Reports Server (NTRS)

Coffin, T.

1986-01-01

A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is reported. The data base represents dynamic pressure measurements obtained during single engine hot firing tests of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is included to estimate spectral trends with SSME power level. Flow Dynamic Environments in High Performance Rocket Engines are described.

Specialized data analysis for the Space Shuttle Main Engine and diagnostic evaluation of advanced propulsion system components

NASA Technical Reports Server (NTRS)

1993-01-01

The Marshall Space Flight Center is responsible for the development and management of advanced launch vehicle propulsion systems, including the Space Shuttle Main Engine (SSME), which is presently operational, and the Space Transportation Main Engine (STME) under development. The SSME's provide high performance within stringent constraints on size, weight, and reliability. Based on operational experience, continuous design improvement is in progress to enhance system durability and reliability. Specialized data analysis and interpretation is required in support of SSME and advanced propulsion system diagnostic evaluations. Comprehensive evaluation of the dynamic measurements obtained from test and flight operations is necessary to provide timely assessment of the vibrational characteristics indicating the operational status of turbomachinery and other critical engine components. Efficient performance of this effort is critical due to the significant impact of dynamic evaluation results on ground test and launch schedules, and requires direct familiarity with SSME and derivative systems, test data acquisition, and diagnostic software. Detailed analysis and evaluation of dynamic measurements obtained during SSME and advanced system ground test and flight operations was performed including analytical/statistical assessment of component dynamic behavior, and the development and implementation of analytical/statistical models to efficiently define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational condition. In addition, the SSME and J-2 data will be applied to develop vibroacoustic environments for advanced propulsion system components, as required. This study will provide timely assessment of engine component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. This contract will be performed through accomplishment of negotiated task orders.

Independent Orbiter Assessment (IOA): Analysis of the orbiter main propulsion system

NASA Technical Reports Server (NTRS)

Mcnicoll, W. J.; Mcneely, M.; Holden, K. A.; Emmons, T. E.; Lowery, H. J.

1987-01-01

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Main Propulsion System (MPS) hardware are documented. The Orbiter MPS consists of two subsystems: the Propellant Management Subsystem (PMS) and the Helium Subsystem. The PMS is a system of manifolds, distribution lines and valves by which the liquid propellants pass from the External Tank (ET) to the Space Shuttle Main Engines (SSMEs) and gaseous propellants pass from the SSMEs to the ET. The Helium Subsystem consists of a series of helium supply tanks and their associated regulators, check valves, distribution lines, and control valves. The Helium Subsystem supplies helium that is used within the SSMEs for inflight purges and provides pressure for actuation of SSME valves during emergency pneumatic shutdowns. The balance of the helium is used to provide pressure to operate the pneumatically actuated valves within the PMS. Each component was evaluated and analyzed for possible failure modes and effects. Criticalities were assigned based on the worst possible effect of each failure mode. Of the 690 failure modes analyzed, 349 were determined to be PCIs.

Specialized data analysis of SSME and advanced propulsion system vibration measurements

NASA Technical Reports Server (NTRS)

Coffin, Thomas; Swanson, Wayne L.; Jong, Yen-Yi

1993-01-01

The basic objectives of this contract were to perform detailed analysis and evaluation of dynamic data obtained during Space Shuttle Main Engine (SSME) test and flight operations, including analytical/statistical assessment of component dynamic performance, and to continue the development and implementation of analytical/statistical models to effectively define nominal component dynamic characteristics, detect anomalous behavior, and assess machinery operational conditions. This study was to provide timely assessment of engine component operational status, identify probable causes of malfunction, and define feasible engineering solutions. The work was performed under three broad tasks: (1) Analysis, Evaluation, and Documentation of SSME Dynamic Test Results; (2) Data Base and Analytical Model Development and Application; and (3) Development and Application of Vibration Signature Analysis Techniques.

SSME Electrical Harness and Cable Development and Evolution

NASA Technical Reports Server (NTRS)

Abrams, Russ; Heflin, Johnny; Burns, Bob; Camper, Scott J.; Hill, Arthur J.

2010-01-01

The Space Shuttle Main Engine (SSME) electrical harness and cable system consists of the various interconnecting devices necessary for operation of complex rocket engine functions. Thirty seven harnesses incorporate unique connectors, backshell adapters, conductors, insulation, shielding, and physical barriers for a long maintenance-free life while providing the means to satisfy performance requirements and to mitigate adverse environmental influences. The objective of this paper is to provide a description of the SSME electrical harness and cable designs as well as the development history and lessons learned.

SSME Post Test Diagnostic System: Systems Section

NASA Technical Reports Server (NTRS)

Bickmore, Timothy

1995-01-01

An assessment of engine and component health is routinely made after each test firing or flight firing of a Space Shuttle Main Engine (SSME). Currently, this health assessment is done by teams of engineers who manually review sensor data, performance data, and engine and component operating histories. Based on review of information from these various sources, an evaluation is made as to the health of each component of the SSME and the preparedness of the engine for another test or flight. The objective of this project - the SSME Post Test Diagnostic System (PTDS) - is to develop a computer program which automates the analysis of test data from the SSME in order to detect and diagnose anomalies. This report primarily covers work on the Systems Section of the PTDS, which automates the analyses performed by the systems/performance group at the Propulsion Branch of NASA Marshall Space Flight Center (MSFC). This group is responsible for assessing the overall health and performance of the engine, and detecting and diagnosing anomalies which involve multiple components (other groups are responsible for analyzing the behavior of specific components). The PTDS utilizes several advanced software technologies to perform its analyses. Raw test data is analyzed using signal processing routines which detect features in the data, such as spikes, shifts, peaks, and drifts. Component analyses are performed by expert systems, which use 'rules-of-thumb' obtained from interviews with the MSFC data analysts to detect and diagnose anomalies. The systems analysis is performed using case-based reasoning. Results of all analyses are stored in a relational database and displayed via an X-window-based graphical user interface which provides ranked lists of anomalies and observations by engine component, along with supporting data plots for each.

Test Results of the Modified Space Shuttle Main Engine at the Marshall Space Flight Center Technology Test Bed Facility

NASA Technical Reports Server (NTRS)

Cook, J.; Dumbacher, D.; Ise, M.; Singer, C.

1990-01-01

A modified space shuttle main engine (SSME), which primarily includes an enlarged throat main combustion chamber with the acoustic cavities removed and a main injector with the stability control baffles removed, was tested. This one-of-a-kind engine's design changes are being evaluated for potential incorporation in the shuttle flight program in the mid-1990's. Engine testing was initiated on September 15, 1988 and has accumulated 1,915 seconds and 19 starts. Testing is being conducted to characterize the engine system performance, combustion stability with the baffle-less injector, and both low pressure oxidizer turbopump (LPOTP) and high pressure oxidizer turbopump (HPOTP) for suction performance. These test results are summarized and compared with the SSME flight configuration data base. Testing of this new generation SSME is the first product from the technology test bed (TTB). Figure test plans for the TTB include the highly instrumented flight configuration SSME and advanced liquid propulsion technology items.

Incipient failure detection of space shuttle main engine turbopump bearings using vibration envelope detection

NASA Technical Reports Server (NTRS)

Hopson, Charles B.

1987-01-01

The results of an analysis performed on seven successive Space Shuttle Main Engine (SSME) static test firings, utilizing envelope detection of external accelerometer data are discussed. The results clearly show the great potential for using envelope detection techniques in SSME incipient failure detection.

SSME HPOTP post-test diagnostic system enhancement project

NASA Technical Reports Server (NTRS)

Bickmore, Timothy W.

1995-01-01

An assessment of engine and component health is routinely made after each test or flight firing of a space shuttle main engine (SSME). Currently, this health assessment is done by teams of engineers who manually review sensor data, performance data, and engine and component operating histories. Based on review of information from these various sources, an evaluation is made as to the health of each component of the SSME and the preparedness of the engine for another test or flight. The objective of this project is to further develop a computer program which automates the analysis of test data from the SSME high-pressure oxidizer turbopump (HPOTP) in order to detect and diagnose anomalies. This program fits into a larger system, the SSME Post-Test Diagnostic System (PTDS), which will eventually be extended to assess the health and status of most SSME components on the basis of test data analysis. The HPOTP module is an expert system, which uses 'rules-of-thumb' obtained from interviews with experts from NASA Marshall Space Flight Center (MSFC) to detect and diagnose anomalies. Analyses of the raw test data are first performed using pattern recognition techniques which result in features such as spikes, shifts, peaks, and drifts being detected and written to a database. The HPOTP module then looks for combination of these features which are indicative of known anomalies, using the rules gathered from the turbomachinery experts. Results of this analysis are then displayed via a graphical user interface which provides ranked lists of anomalies and observations by engine component, along with supporting data plots for each.

A Three-Dimensional Parallel Time-Accurate Turbopump Simulation Procedure Using Overset Grid System

NASA Technical Reports Server (NTRS)

Kiris, Cetin; Chan, William; Kwak, Dochan

2002-01-01

The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort provides developers with information such as transient flow phenomena at start up, and nonuniform inflows, and will eventually impact on system vibration and structures. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. CAD to solution auto-scripting capability is being developed for turbopump applications. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 3000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability are presented along with the performance of parallel versions of the code.

Time-Dependent Simulations of Turbopump Flows

NASA Technical Reports Server (NTRS)

Kris, Cetin C.; Kwak, Dochan

2001-01-01

The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort will provide developers with information such as transient flow phenomena at start up, impact of non-uniform inflows, system vibration and impact on the structure. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Time-accuracy of the scheme has been evaluated with simple test cases. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 2000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability will be presented along with the performance of parallel versions of the code.

LVQ and backpropagation neural networks applied to NASA SSME data

NASA Technical Reports Server (NTRS)

Doniere, Timothy F.; Dhawan, Atam P.

1993-01-01

Feedfoward neural networks with backpropagation learning have been used as function approximators for modeling the space shuttle main engine (SSME) sensor signals. The modeling of these sensor signals is aimed at the development of a sensor fault detection system that can be used during ground test firings. The generalization capability of a neural network based function approximator depends on the training vectors which in this application may be derived from a number of SSME ground test-firings. This yields a large number of training vectors. Large training sets can cause the time required to train the network to be very large. Also, the network may not be able to generalize for large training sets. To reduce the size of the training sets, the SSME test-firing data is reduced using the learning vector quantization (LVQ) based technique. Different compression ratios were used to obtain compressed data in training the neural network model. The performance of the neural model trained using reduced sets of training patterns is presented and compared with the performance of the model trained using complete data. The LVQ can also be used as a function approximator. The performance of the LVQ as a function approximator using reduced training sets is presented and compared with the performance of the backpropagation network.

Nonlinear heat transfer and structural analyses of SSME turbine blades

NASA Technical Reports Server (NTRS)

Abdul-Aziz, A.; Kaufman, A.

1987-01-01

Three-dimensional nonlinear finite-element heat transfer and structural analyses were performed for the first stage high-pressure fuel turbopump blade of the space shuttle main engine (SSME). Directionally solidified (DS) MAR-M 246 material properties were considered for the analyses. Analytical conditions were based on a typical test stand engine cycle. Blade temperature and stress-strain histories were calculated using MARC finite-element computer code. The study was undertaken to assess the structural response of an SSME turbine blade and to gain greater understanding of blade damage mechanisms, convective cooling effects, and the thermal-mechanical effects.

Performance of the split-symbol moments SNR estimator in the presence of inter-symbol interference

NASA Technical Reports Server (NTRS)

Shah, B.; Hinedi, S.

1989-01-01

The Split-Symbol Moments Estimator (SSME) is an algorithm that is designed to estimate symbol signal-to-noise ratio (SNR) in the presence of additive white Gaussian noise (AWGN). The performance of the SSME algorithm in band-limited channels is examined. The effects of the resulting inter-symbol interference (ISI) are quantified. All results obtained are in closed form and can be easily evaluated numerically for performance prediction purposes. Furthermore, they are validated through digital simulations.

Turning Fiction Into Non-fiction for Signal-to-Noise Ratio Estimation -- The Time-Multiplexed and Adaptive Split-Symbol Moments Estimator

NASA Astrophysics Data System (ADS)

Simon, M.; Dolinar, S.

2005-08-01

A means is proposed for realizing the generalized split-symbol moments estimator (SSME) of signal-to-noise ratio (SNR), i.e., one whose implementation on the average allows for a number of subdivisions (observables), 2L, per symbol beyond the conventional value of two, with other than an integer value of L. In theory, the generalized SSME was previously shown to yield optimum performance for a given true SNR, R, when L=R/sqrt(2) and thus, in general, the resulting estimator was referred to as the fictitious SSME. Here we present a time-multiplexed version of the SSME that allows it to achieve its optimum value of L as above (to the extent that it can be computed as the average of a sum of integers) at each value of SNR and as such turns fiction into non-fiction. Also proposed is an adaptive algorithm that allows the SSME to rapidly converge to its optimum value of L when in fact one has no a priori information about the true value of SNR.

STS-37 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W.

1991-05-01

The STS-37 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities during this thirty-ninth flight of the Space Shuttle and the eighth flight of the Orbiter Vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) (designated as ET-37/LWT-30); three Space Shuttle main engines (SSME's) (serial numbers 2019, 2031, and 2107 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-042. The primary objective of this flight was to successfully deploy the Gamma Ray Observatory (GRO) payload. The secondary objectives were to successfully perform all operations necessary to support the requirements of the Protein Crystal Growth (PCG) Block 2 version, Radiation Monitoring Experiment-3 (RME-3), Ascent Particle Monitor (APM), Shuttle Amateur Radio Experiment-2 (SAREX-2), Air Force Maui Optical Site Calibration Test (AMOS), Bioserve Instrumentation Technology Associates Materials Dispersion Apparatus (BIMDA), and the Crew and Equipment Transfer Aids (CETA) payloads.

STS-37 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1991-01-01

The STS-37 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem activities during this thirty-ninth flight of the Space Shuttle and the eighth flight of the Orbiter Vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) (designated as ET-37/LWT-30); three Space Shuttle main engines (SSME's) (serial numbers 2019, 2031, and 2107 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-042. The primary objective of this flight was to successfully deploy the Gamma Ray Observatory (GRO) payload. The secondary objectives were to successfully perform all operations necessary to support the requirements of the Protein Crystal Growth (PCG) Block 2 version, Radiation Monitoring Experiment-3 (RME-3), Ascent Particle Monitor (APM), Shuttle Amateur Radio Experiment-2 (SAREX-2), Air Force Maui Optical Site Calibration Test (AMOS), Bioserve Instrumentation Technology Associates Materials Dispersion Apparatus (BIMDA), and the Crew and Equipment Transfer Aids (CETA) payloads.

Performance predictions for an SSME configuration with an enlarged throat

NASA Technical Reports Server (NTRS)

Nickerson, G. R.; Dang, L. D.

1985-01-01

The Two Dimensional Kinetics (TDK) computer program that was recently developed for NASA was used to predict the performance of a Large Throat Configuration of the Space Shuttle Main Engine (SSME). Calculations indicate that the current design SSME contains a shock wave that is induced by the nozzle wall shape. In the Large Throat design an even stronger shock wave is predicted. Because of the presence of this shock wave, earlier performance predictions that have neglected shock wave effects have been questioned. The JANNAF thrust chamber performance prediction procedures given in a reference were applied. The analysis includes the effects of two dimensional reacting flow with a shock wave. The effects of the boundary layer with a regenatively cooled wall are also included. A Purdue computer program was used to compute axially symmetric supersonic nozzle flows with an induced shock, but is restricted to flows with a constant ratio of specific heats. Thus, the TDK program was also run with ths assumption and the results of the two programs were compared.

Cryogenic, high speed, turbopump bearing cooling requirements

NASA Technical Reports Server (NTRS)

Dolan, Fred J.; Gibson, Howard G.; Cannon, James L.; Cody, Joe C.

1988-01-01

Although the Space Shuttle Main Engine (SSME) has repeatedly demonstrated the capability to perform during launch, the High Pressure Oxidizer Turbopump (HPOTP) main shaft bearings have not met their 7.5 hour life requirement. A tester is being employed to provide the capability of subjecting full scale bearings and seals to speeds, loads, propellants, temperatures, and pressures which simulate engine operating conditions. The tester design permits much more elaborate instrumentation and diagnostics than could be accommodated in an SSME turbopump. Tests were made to demonstrate the facilities; and the devices' capabilities, to verify the instruments in its operating environment and to establish a performance baseline for the flight type SSME HPOTP Turbine Bearing design. Bearing performance data from tests are being utilized to generate: (1) a high speed, cryogenic turbopump bearing computer mechanical model, and (2) a much improved, very detailed thermal model to better understand bearing internal operating conditions. Parametric tests were also made to determine the effects of speed, axial loads, coolant flow rate, and surface finish degradation on bearing performance.

Thermal-structural analyses of Space Shuttle Main Engine (SSME) hot section components

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Thompson, Robert L.

1988-01-01

Three dimensional nonlinear finite element heat transfer and structural analyses were performed for the first stage high pressure fuel turbopump (HPFTP) blade of the space shuttle main engine (SSME). Directionally solidified (DS) MAR-M 246 and single crystal (SC) PWA-1480 material properties were used for the analyses. Analytical conditions were based on a typical test stand engine cycle. Blade temperature and stress strain histories were calculated by using the MARC finite element computer code. The structural response of an SSME turbine blade was assessed and a greater understanding of blade damage mechanisms, convective cooling effects, and thermal mechanical effects was gained.

Research pressure instrumentation for NASA space shuttle main engine

NASA Technical Reports Server (NTRS)

Anderson, P. J.; Nussbaum, P.; Gustafson, G.

1985-01-01

The breadboard feasibility model of a silicon piezoresistive pressure transducer suitable for space shuttle main engine (SSME) applications was demonstrated. The development of pressure instrumentation for the SSME was examined. The objective is to develop prototype pressure transducers which are targeted to meet the SSME performance design goals and to fabricate, test and deliver a total of 10 prototype units. Effective utilization of the many advantages of silicon piezoresistive strain sensing technology to achieve the objectives of advanced state-of-the-art pressure sensors for reliability, accuracy and ease of manufacture is analyzed. Integration of multiple functions on a single chip is the key attribute of the technology.

Dynamic analysis of nonlinear rotor-housing systems

NASA Technical Reports Server (NTRS)

Noah, Sherif T.

1988-01-01

Nonlinear analysis methods are developed which will enable the reliable prediction of the dynamic behavior of the space shuttle main engine (SSME) turbopumps in the presence of bearing clearances and other local nonlinearities. A computationally efficient convolution method, based on discretized Duhamel and transition matrix integral formulations, is developed for the transient analysis. In the formulation, the coupling forces due to the nonlinearities are treated as external forces acting on the coupled subsystems. Iteration is utilized to determine their magnitudes at each time increment. The method is applied to a nonlinear generic model of the high pressure oxygen turbopump (HPOTP). As compared to the fourth order Runge-Kutta numerical integration methods, the convolution approach proved to be more accurate and more highly efficient. For determining the nonlinear, steady-state periodic responses, an incremental harmonic balance method was also developed. The method was successfully used to determine dominantly harmonic and subharmonic responses fo the HPOTP generic model with bearing clearances. A reduction method similar to the impedance formulation utilized with linear systems is used to reduce the housing-rotor models to their coordinates at the bearing clearances. Recommendations are included for further development of the method, for extending the analysis to aperiodic and chaotic regimes and for conducting critical parameteric studies of the nonlinear response of the current SSME turbopumps.

A Three Dimensional Parallel Time Accurate Turbopump Simulation Procedure Using Overset Grid Systems

NASA Technical Reports Server (NTRS)

Kiris, Cetin; Chan, William; Kwak, Dochan

2001-01-01

The objective of the current effort is to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine, including high-fidelity unsteady turbopump flow analysis. This capability is needed to support the design of pump sub-systems for advanced space transportation vehicles that are likely to involve liquid propulsion systems. To date, computational tools for design/analysis of turbopump flows are based on relatively lower fidelity methods. An unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available for real-world engineering applications. The present effort provides developers with information such as transient flow phenomena at start up, and non-uniform inflows, and will eventually impact on system vibration and structures. In the proposed paper, the progress toward the capability of complete simulation of the turbo-pump for a liquid rocket engine is reported. The Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. CAD to solution auto-scripting capability is being developed for turbopump applications. The relative motion of the grid systems for the rotor-stator interaction was obtained using overset grid techniques. Unsteady computations for the SSME turbo-pump, which contains 114 zones with 34.5 million grid points, are carried out on Origin 3000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability will be presented along with the performance of parallel versions of the code.

Unsteady Turbopump Flow Simulations

NASA Technical Reports Server (NTRS)

Centin, Kiris C.; Kwak, Dochan

2001-01-01

The objective of the current effort is two-fold: 1) to provide a computational framework for design and analysis of the entire fuel supply system of a liquid rocket engine; and 2) to provide high-fidelity unsteady turbopump flow analysis capability to support the design of pump sub-systems for advanced space transportation vehicle. Since the space launch systems in the near future are likely to involve liquid propulsion system, increasing the efficiency and reliability of the turbopump components is an important task. To date, computational tools for design/analysis of turbopump flow are based on relatively lower fidelity methods. Unsteady, three-dimensional viscous flow analysis tool involving stationary and rotational components for the entire turbopump assembly has not been available, at least, for real-world engineering applications. Present effort is an attempt to provide this capability so that developers of the vehicle will be able to extract such information as transient flow phenomena for start up, impact of non-uniform inflow, system vibration and impact on the structure. Those quantities are not readily available from simplified design tools. In this presentation, the progress being made toward complete turbo-pump simulation capability for a liquid rocket engine is reported. Space Shuttle Main Engine (SSME) turbo-pump is used as a test case for the performance evaluation of the hybrid MPI/Open-MP and MLP versions of the INS3D code. Relative motion of the grid system for rotor-stator interaction was obtained by employing overset grid techniques. Time-accuracy of the scheme has been evaluated by using simple test cases. Unsteady computations for SSME turbopump, which contains 106 zones with 34.5 Million grid points, are currently underway on Origin 2000 systems at NASA Ames Research Center. Results from these time-accurate simulations with moving boundary capability and the performance of the parallel versions of the code will be presented.

Summary of Recent Inducer Testing at MSFC and Future Plans

NASA Technical Reports Server (NTRS)

Skelley, Stephen

2003-01-01

This viewgraph presentation covers water flow tests on the RS-83 Main LOX Inducer for the Space Shuttle Main Engine (SSME). The presentation lists recent water tests on the SSME liquid oxygen (LOX) pump inducer, includes images and diagrams of the water test facility at Marshall Space Flight Center (MSFC), profiles inducer hydrodynamic forces, and diagrams the performance of the RS-83 inducer.

Cold flow testing of the Space Shuttle Main Engine alternate turbopump development high pressure fuel turbine model

NASA Technical Reports Server (NTRS)

Gaddis, Stephen W.; Hudson, Susan T.; Johnson, P. D.

1992-01-01

NASA's Marshall Space Flight Center has established a cold airflow turbine test program to experimentally determine the performance of liquid rocket engine turbopump drive turbines. Testing of the SSME alternate turbopump development (ATD) fuel turbine was conducted for back-to-back comparisons with the baseline SSME fuel turbine results obtained in the first quarter of 1991. Turbine performance, Reynolds number effects, and turbine diagnostics, such as stage reactions and exit swirl angles, were investigated at the turbine design point and at off-design conditions. The test data showed that the ATD fuel turbine test article was approximately 1.4 percent higher in efficiency and flowed 5.3 percent more than the baseline fuel turbine test article. This paper describes the method and results used to validate the ATD fuel turbine aerodynamic design. The results are being used to determine the ATD high pressure fuel turbopump (HPFTP) turbine performance over its operating range, anchor the SSME ATD steady-state performance model, and validate various prediction and design analyses.

Faces of the SSME (Group 2)

NASA Technical Reports Server (NTRS)

2010-01-01

Members of the Space Shuttle Main Engine (SSME) team review some of their memories of working on the SSME and the importance of the SSME to the success of the Shuttle program. There are many views of shuttle launches.

Faces of SSME (Group 13)

NASA Technical Reports Server (NTRS)

2009-01-01

Members of the Space Shuttle Main Engine (SSME) team review some of their memories of working on the SSME and the importance of the SSME to the success of the Shuttle program. There are many views of shuttle launches.

Space Shuttle Main Engine Quantitative Risk Assessment: Illustrating Modeling of a Complex System with a New QRA Software Package

NASA Technical Reports Server (NTRS)

Smart, Christian

1998-01-01

During 1997, a team from Hernandez Engineering, MSFC, Rocketdyne, Thiokol, Pratt & Whitney, and USBI completed the first phase of a two year Quantitative Risk Assessment (QRA) of the Space Shuttle. The models for the Shuttle systems were entered and analyzed by a new QRA software package. This system, termed the Quantitative Risk Assessment System(QRAS), was designed by NASA and programmed by the University of Maryland. The software is a groundbreaking PC-based risk assessment package that allows the user to model complex systems in a hierarchical fashion. Features of the software include the ability to easily select quantifications of failure modes, draw Event Sequence Diagrams(ESDs) interactively, perform uncertainty and sensitivity analysis, and document the modeling. This paper illustrates both the approach used in modeling and the particular features of the software package. The software is general and can be used in a QRA of any complex engineered system. The author is the project lead for the modeling of the Space Shuttle Main Engines (SSMEs), and this paper focuses on the modeling completed for the SSMEs during 1997. In particular, the groundrules for the study, the databases used, the way in which ESDs were used to model catastrophic failure of the SSMES, the methods used to quantify the failure rates, and how QRAS was used in the modeling effort are discussed. Groundrules were necessary to limit the scope of such a complex study, especially with regard to a liquid rocket engine such as the SSME, which can be shut down after ignition either on the pad or in flight. The SSME was divided into its constituent components and subsystems. These were ranked on the basis of the possibility of being upgraded and risk of catastrophic failure. Once this was done the Shuttle program Hazard Analysis and Failure Modes and Effects Analysis (FMEA) were used to create a list of potential failure modes to be modeled. The groundrules and other criteria were used to screen out the many failure modes that did not contribute significantly to the catastrophic risk. The Hazard Analysis and FMEA for the SSME were also used to build ESDs that show the chain of events leading from the failure mode occurence to one of the following end states: catastrophic failure, engine shutdown, or siccessful operation( successful with respect to the failure mode under consideration).

Develop advanced nonlinear signal analysis topographical mapping system

NASA Technical Reports Server (NTRS)

1994-01-01

The Space Shuttle Main Engine (SSME) has been undergoing extensive flight certification and developmental testing, which involves some 250 health monitoring measurements. Under the severe temperature, pressure, and dynamic environments sustained during operation, numerous major component failures have occurred, resulting in extensive engine hardware damage and scheduling losses. To enhance SSME safety and reliability, detailed analysis and evaluation of the measurements signal are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce catastrophic system failure risks and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. The basic objective of this contract are threefold: (1) develop and validate a hierarchy of innovative signal analysis techniques for nonlinear and nonstationary time-frequency analysis. Performance evaluation will be carried out through detailed analysis of extensive SSME static firing and flight data. These techniques will be incorporated into a fully automated system; (2) develop an advanced nonlinear signal analysis topographical mapping system (ATMS) to generate a Compressed SSME TOPO Data Base (CSTDB). This ATMS system will convert tremendous amount of complex vibration signals from the entire SSME test history into a bank of succinct image-like patterns while retaining all respective phase information. High compression ratio can be achieved to allow minimal storage requirement, while providing fast signature retrieval, pattern comparison, and identification capabilities; and (3) integrate the nonlinear correlation techniques into the CSTDB data base with compatible TOPO input data format. Such integrated ATMS system will provide the large test archives necessary for quick signature comparison. This study will provide timely assessment of SSME component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. The final result of this program will yield an ATMS system of nonlinear and nonstationary spectral analysis software package integrated with the Compressed SSME TOPO Data Base (CSTDB) on the same platform. This system will allow NASA engineers to retrieve any unique defect signatures and trends associated with different failure modes and anomalous phenomena over the entire SSME test history across turbo pump families.

Develop advanced nonlinear signal analysis topographical mapping system

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1993-01-01

The SSME has been undergoing extensive flight certification and developmental testing, which involves some 250 health monitoring measurements. Under the severe temperature pressure, and dynamic environments sustained during operation, numerous major component failures have occurred, resulting in extensive engine hardware damage and scheduling losses. To enhance SSME safety and reliability, detailed analysis and evaluation of the measurements signal are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce catastrophic system failure risks and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. The basic objective of this contract are threefold: (1) Develop and validate a hierarchy of innovative signal analysis techniques for nonlinear and nonstationary time-frequency analysis. Performance evaluation will be carried out through detailed analysis of extensive SSME static firing and flight data. These techniques will be incorporated into a fully automated system. (2) Develop an advanced nonlinear signal analysis topographical mapping system (ATMS) to generate a Compressed SSME TOPO Data Base (CSTDB). This ATMS system will convert tremendous amounts of complex vibration signals from the entire SSME test history into a bank of succinct image-like patterns while retaining all respective phase information. A high compression ratio can be achieved to allow the minimal storage requirement, while providing fast signature retrieval, pattern comparison, and identification capabilities. (3) Integrate the nonlinear correlation techniques into the CSTDB data base with compatible TOPO input data format. Such integrated ATMS system will provide the large test archives necessary for a quick signature comparison. This study will provide timely assessment of SSME component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. The final result of this program will yield an ATMS system of nonlinear and nonstationary spectral analysis software package integrated with the Compressed SSME TOPO Data Base (CSTDB) on the same platform. This system will allow NASA engineers to retrieve any unique defect signatures and trends associated with different failure modes and anomalous phenomena over the entire SSME test history across turbo pump families.

CFD simulation of coaxial injectors

NASA Technical Reports Server (NTRS)

Landrum, D. Brian

1993-01-01

The development of improved performance models for the Space Shuttle Main Engine (SSME) is an important, ongoing program at NASA MSFC. These models allow prediction of overall system performance, as well as analysis of run-time anomalies which might adversely affect engine performance or safety. Due to the complexity of the flow fields associated with the SSME, NASA has increasingly turned to Computational Fluid Dynamics (CFD) techniques as modeling tools. An important component of the SSME system is the fuel preburner, which consists of a cylindrical chamber with a plate containing 264 coaxial injector elements at one end. A fuel rich mixture of gaseous hydrogen and liquid oxygen is injected and combusted in the chamber. This process preheats the hydrogen fuel before it enters the main combustion chamber, powers the hydrogen turbo-pump, and provides a heat dump for nozzle cooling. Issues of interest include the temperature and pressure fields at the turbine inlet and the thermal compatibility between the preburner chamber and injector plate. Performance anomalies can occur due to incomplete combustion, blocked injector ports, etc. The performance model should include the capability to simulate the effects of these anomalies. The current approach to the numerical simulation of the SSME fuel preburner flow field is to use a global model based on the MSFC sponsored FNDS code. This code does not have the capabilities of modeling several aspects of the problem such as detailed modeling of the coaxial injectors. Therefore, an effort has been initiated to develop a detailed simulation of the preburner coaxial injectors and provide gas phase boundary conditions just downstream of the injector face as input to the FDNS code. This simulation should include three-dimensional geometric effects such as proximity of injectors to baffles and chamber walls and interaction between injectors. This report describes an investigation into the numerical simulation of GH2/LOX coaxial injectors. The following sections will discuss the physical aspects of injectors, the CFD code employed, and preliminary results of a simulation of a single coaxial injector for which experimental data is available. It is hoped that this work will lay the foundation for the development of a unique and useful tool to support the SSME program.

Computational Fluid Dynamics (CFD) Analyses in Support of Space Shuttle Main Engine (SSME) Heat Exchanger (HX) Vane Cracking Investigation

NASA Technical Reports Server (NTRS)

Garcia, Roberto; Benjamin, Theodore G.; Cornelison, J.; Fredmonski, A. J.

1993-01-01

Integration issues involved with installing the alternate turbopump (ATP) High Pressure Oxygen Turbopump (HPOTP) into the SSME have raised questions regarding the flow in the HPOTP turnaround duct (TAD). Steady-state Navier-Stokes CFD analyses have been performed by NASA and Pratt & Whitney (P&W) to address these questions. The analyses have consisted of two-dimensional axisymmetric calculations done at Marshall Space Flight Center and three-dimensional calculations performed at P&W. These analyses have identified flowfield differences between the baseline ATP and the Rocketdyne configurations. The results show that the baseline ATP configuration represents a more severe environment to the inner HX guide vane. This vane has limited life when tested in conjunction with the ATP but infinite life when tested with the current SSME HPOTP. The CFD results have helped interpret test results and have been used to assess proposed redesigns. This paper includes details of the axisymmetric model, its results, and its contribution towards resolving the problem.

An evaluation of dry film lubricants and substrate materials for use on SSME gimbal bearings

NASA Technical Reports Server (NTRS)

Harp, J. A.

1976-01-01

Failure of the spherical bearing shaft of the Space Shuttle Main Engine (SSME) gimbal bearing assembly was encountered during Design Verification Specification testing of the full scale engine. Investigation revealed that the failure was caused by a deficiency in the lubrication system. Based upon the materials and gimbal operating conditions, a lubricant of MoS2 and graphite with a ceramic binder was the best lubricant candidate for this particular application; however, the decision to implement the change was not made without verification testing. Scaled down simulation testing was performed. Four different substrate materials and eight different dry film lubricants were subjected to tests under simulated SSME environmental and stress load conditions. The test specimens were evaluated for friction and operating life. Each test specimen was subjected to cyclic operation under load until failure. The force required to move the bearing surfaces relative to each other was monitored throughout the test, thus providing analytical data for derivation of the coefficient of friction. Results indicate that the MoS2/graphite lubricant with ceramic binder proved to be superior from the standpoint of endurance and also from the standpoint of friction reducing capabilities when applied to the titanium substrate material used on SSME. Endurance of this lubricant was approximately 16 times that of the lubricant which was being used when the SSME gimbal failed.

A qualitative approach to systemic diagnosis of the SSME

NASA Technical Reports Server (NTRS)

Bickmore, Timothy W.; Maul, William A.

1993-01-01

A generic software architecture has been developed for posttest diagnostics of rocket engines, and is presently being applied to the posttest analysis of the SSME. This investigation deals with the Systems Section module of the architecture, which is presently under development. Overviews of the manual SSME systems analysis process and the overall SSME diagnostic system architecture are presented.

Space shuttle three main engine return to launch site abort

NASA Technical Reports Server (NTRS)

Carter, J. F.; Bown, R. L.

1975-01-01

A Return-to-Launch-Site (RTLS) abort with three Space Shuttle Main Engines (SSME) operational was examined. The results are trajectories and main engine cutoff conditions that are approximately the same as for a two SSME case. Requiring the three SSME solution to match the two SSME abort eliminates additional crew training and is accomplished with negligible software impact.

SSME digital control design characteristics

NASA Technical Reports Server (NTRS)

Mitchell, W. T.; Searle, R. F.

1985-01-01

To protect against a latent programming error (software fault) existing in an untried branch combination that would render the space shuttle out of control in a critical flight phase, the Backup Flight System (BFS) was chartered to provide a safety alternative. The BFS is designed to operate in critical flight phases (ascent and descent) by monitoring the activities of the space shuttle flight subsystems that are under control of the primary flight software (PFS) (e.g., navigation, crew interface, propulsion), then, upon manual command by the flightcrew, to assume control of the space shuttle and deliver it to a noncritical flight condition (safe orbit or touchdown). The problems associated with the selection of the PFS/BFS system architecture, the internal BFS architecture, the fault tolerant software mechanisms, and the long term BFS utility are discussed.

Initially Researches for the Development of SSME under the Background of IOT

NASA Astrophysics Data System (ADS)

Han, Kun; Liu, Shurong; Zhang, Dacheng; Han, Ying

The Internet Of Things (IOT) is proposed in the 1990s. The original intention has been put forward is people to things and things to things can deliver information like person as. IOT broke the human traditional thinking. This paper researches the practical function of IOT to expand the theory of Services Sciences, Management and Engineering (SSME). On the analysis of the key technology and model of IOT, the events-driven SSME model based on IOT, and the IOT framework based on SSME, it further studies the importance of IOT in the field of SSME.

Emission spectra of selected SSME elements and materials

NASA Technical Reports Server (NTRS)

Tejwani, Gopal D.; Vandyke, David B.; Bircher, Felix E.; Gardner, Donald G.; Chenevert, Donald J.

1992-01-01

Stennis Space Center (SSC) is pursuing the advancement of experimental techniques and theoretical developments in the field of plume spectroscopy for application to rocket development testing programs and engine health monitoring. Exhaust plume spectral data for the Space Shuttle Main Engine (SSME) are routinely acquired. The usefulness of this data depends upon qualitative and quantitative interpretation of spectral features and their correlation with the engine performance. A knowledge of the emission spectral characteristics of effluent materials in the exhaust plume is essential. A study of SSME critical components and their materials identified 30 elements and 53 materials whose engine exhaust plume spectral might be required. The most important were evaluated using SSC's Diagnostic Testbed Facility Thruster (DTFT), a 1200-lbf, liquid oxygen/gaseous hydrogen rocket engine which very nearly replicates the temperature and pressure conditions of the SSME exhaust plume in the first Mach diamond. This report presents the spectral data for the 10 most important elements and 27 most important materials which are strongly to moderately emitting in the DTFT exhaust plume. The covered spectral range is 300 to 426 nm and the spectral resolution is 0.25 nm. Spectral line identification information is provided and line interference effects are considered.

Closeup View of the Space Shuttle Main Engine (SSME) 2044 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up View of the Space Shuttle Main Engine (SSME) 2044 mounted in a SSME Engine Handler in the SSME processing Facility at Kennedy Space Center. This view shows SSME 2044 with its expansion nozzle removed and an Engine Leak-Test Plug is set in the throat of the Main Combustion Chamber in the approximate center of the image, the insulated, High-Pressure Fuel Turbopump sits below that and the Low Pressure Oxidizer Turbopump Discharge Duct sits towards the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Studies and analyses of the Space Shuttle Main Engine: SSME failure data review, diagnostic survey and SSME diagnostic evaluation

NASA Technical Reports Server (NTRS)

Glover, R. C.; Kelley, B. A.; Tischer, A. E.

1986-01-01

The results of a review of the Space Shuttle Main Engine (SSME) failure data for the period 1980 through 1983 are presented. The data was collected, evaluated, and ranked according to procedures established during this study. A number of conclusions and recommendations are made based upon this failure data review. The results of a state-of-the-art diagnostic survey are also presented. This survey covered a broad range of diagnostic sensors and techniques and the findings were evaluated for application to the SSME. Finally, a discussion of the initial activities for the on-going SSME diagnostic evaluation is included.

Cost effective launch operations of the SSME

NASA Technical Reports Server (NTRS)

Klatt, F. P.

1985-01-01

The Space Shuttle Main Engine (SSME) represents the beginning of reusable rocket engine operations in the space transportation system (STS). Steps taken to reduce the overall cost of flight operations of the SSME by improving turnaround operations, extending the life of the engine, and improving the cost effectiveness of overhaul operations at the Canoga Park home plant are described. Ground certification testing to ensure safe launch operations is described, as well as certification extension testing that leads to a service life equivalent to 40 flights. The proven flight record of the SSME, which has demonstrated the utility of the SSME as a key component of America's space transportation system, is discussed.

Fluctuating Pressure Analysis of a 2-D SSME Nozzle Air Flow Test

NASA Technical Reports Server (NTRS)

Reed, Darren; Hidalgo, Homero

1996-01-01

To better understand the Space Shuttle Main Engine (SSME) startup/shutdown tansients, an airflow test of a two dimensional nozzle was conducted at Marshall Space Flight Center's trisonic wind tunnel. Photographic and other instrumentation show during an SSME start large nozzle shell distortions occur as the Mach disk is passing through the nozzle. During earlier develop of the SSME, this startup transient resulted in low cycle fatigue failure of one of the LH2 feedlines. The two dimensional SSME nozzle test was designed to measure the static and fluctuating pressure environment and color Schlieren video during the startup and shutdown phases of the run profile.

Radiation effect on rocket engine performance

NASA Technical Reports Server (NTRS)

Chiu, Huei-Huang; Kross, K. W.; Krebsbach, A. N.

1990-01-01

Critical problem areas involving the effect of radiation on the combustion of bipropellants are addressed by formulating a universal scaling law in combination with a radiation-enhanced vaporization combustion model. Numerical algorithms are developed and data pertaining to the Variable Thrust Engine (VTE) and the Space Shuttle Main Engine (SSME) are used to conduct parametric sensitivity studies to predict the principal intercoupling effects of radiation. The analysis reveals that low-enthalpy engines, such as the VTE, are vulnerable to a substantial performance setback due to radiative loss, whereas the performance of high-enthalpy engines such as the SSME are hardly affected over a broad range of engine operation. Combustion enhancement by radiative heating of the propellant has a significant impact on propellants with high absorptivity.

Summary of Results from Space Shuttle Main Engine Off-Nominal Testing

NASA Technical Reports Server (NTRS)

Horton, James F.; Megivern, Jeffrey M.; McNutt, Leslie M.

2011-01-01

This paper is a summary of Space Shuttle Main Engine (SSME) off-nominal testing that occurred during 2008 and 2009. During the last two years of planned SSME testing at Stennis Space Center, Pratt & Whitney Rocketdyne worked with their NASA MSFC customer to systematically identify, develop, assess, and implement challenging test objectives in order to expand the knowledge of one of the world s most reliable and highly tested large rocket engine. The objectives successfully investigated three main areas of interest expanding engine performance margins, demonstrating system operational capabilities, and establishing ground work for new rocket engine technology. The testing gave the Space Shuttle Program new options to safely fly out the flight manifest and provided Pratt & Whitney Rocketdyne and NASA new insight into the operational capabilities of the SSME, capabilities which can be used in assessing potential future applications of the RS-25 engine.

Parametric study in weld mismatch of longitudinally welded SSME HPFTP inlet

NASA Technical Reports Server (NTRS)

Min, J. B.; Spanyer, K. L.; Brunair, R. M.

1991-01-01

Welded joints are an essential part of pressure vessels such as the Space Shuttle Main Engine (SSME) Turbopumps. Defects produced in the welding process can be detrimental to weld performance. Recently, review of the SSME high pressure fuel turbopump (HPFTP) titanium inlet x rays revealed several weld discrepancies such as penetrameter density issues, film processing discrepancies, weld width discrepancies, porosity, lack of fusion, and weld offsets. Currently, the sensitivity of welded structures to defects is of concern. From a fatigue standpoint, weld offset may have a serious effect since local yielding, in general, aggravates cyclic stress effects. Therefore, the weld offset issue is considered. Using the finite element method and mathematical formulations, parametric studies were conducted to determine the influence of weld offsets and a variation of weld widths in longitudinally welded cylindrical structures with equal wall thickness on both sides of the joint. From the study, the finite element results and theoretical solutions are presented.

Operational Issues in the Development of a Cost-Effective Reusable LOX/LH2 Engine

NASA Technical Reports Server (NTRS)

Ballard, Richard O.

2003-01-01

The NASA Space Launch Initiative (SLI) was initiated in early 2001 to conduct technology development and to reduce the business and technical risk associated with developing the next-generation reusable launch system. In the field of main propulsion, two LOXLH2 rocket engine systems, the Pratt & Whitney / Aerojet Joint Venture (JV) COBRA and the Rocketdyne RS-83, were funded to develop a safe, economical, and reusable propulsion system. Given that a large-thrust reusable rocket engine program had not been started in the U.S. since 1971, with the Space Shuttle Main Engine (SSME), this provided an opportunity to build on the experience developed on the SSME system, while exploiting advances in technology that had occurred in the intervening 30 years. One facet of engine development that was identified as being especially vital in order to produce an optimal system was in the areas of operability and maintainability. In order to achieve the high levels of performance required by the Space Shuttle, the SSME system is highly complex with very tight tolerances and detailed requirements. Over the lifetime of the SSME program, the engine has required a high level of manpower to support the performance of inspections, maintenance (scheduled and unscheduled) and operations (prelaunch and post-flight). As a consequence, the labor- intensive needs of the SSME provide a significant impact to the overall cost efficiency of the Space Transportation System (STS). One of the strategic goals of the SLI is to reduce cost by requiring the engine(s) to be easier (Le. less expensive) to operate and maintain. The most effective means of accomplishing this goal is to infuse the operability and maintainability features into the engine design from the start. This paper discusses some of the operational issues relevant to a reusable LOx/LH2 main engine, and the means by which their impact is mitigated in the design phase.

SSME alternate turbopump (pump section) axial load analysis

NASA Technical Reports Server (NTRS)

Crease, G. A.; Rosello, A., Jr.; Fetfatsidis, A. K.

1989-01-01

A flow balancing computer program constructed to calculate the axial loads on the Space Shuttle Main Engine (SSME) alternate turbopumps (ATs) pump sections are described. The loads are used in turn to determine load balancing piston design requirements. The application of the program to the inlet section, inducer/impeller/stage, bearings, seals, labyrinth, damper, piston, face and corner, and stationary/rotating surfaces is indicated. Design analysis results are reported which show that the balancing piston's designs are adequate and that performance and life will not be degraded by the turbopump's axial load characteristics.

Thrust chamber performance using Navier-Stokes solution. [space shuttle main engine viscous nozzle calculation

NASA Technical Reports Server (NTRS)

Chan, J. S.; Freeman, J. A.

1984-01-01

The viscous, axisymmetric flow in the thrust chamber of the space shuttle main engine (SSME) was computed on the CRAY 205 computer using the general interpolants method (GIM) code. Results show that the Navier-Stokes codes can be used for these flows to study trends and viscous effects as well as determine flow patterns; but further research and development is needed before they can be used as production tools for nozzle performance calculations. The GIM formulation, numerical scheme, and computer code are described. The actual SSME nozzle computation showing grid points, flow contours, and flow parameter plots is discussed. The computer system and run times/costs are detailed.

FNAS/summer faculty fellowship research continuation program. Task 6: Integrated model development for liquid fueled rocket propulsion systems. Task 9: Aspects of model-based rocket engine condition monitoring and control

NASA Technical Reports Server (NTRS)

Santi, L. Michael; Helmicki, Arthur J.

1993-01-01

The objective of Phase I of this research effort was to develop an advanced mathematical-empirical model of SSME steady-state performance. Task 6 of Phase I is to develop component specific modification strategy for baseline case influence coefficient matrices. This report describes the background of SSME performance characteristics and provides a description of the control variable basis of three different gains models. The procedure used to establish influence coefficients for each of these three models is also described. Gains model analysis results are compared to Rocketdyne's power balance model (PBM).

Modeling of rolling element bearing mechanics

NASA Technical Reports Server (NTRS)

Greenhill, L. M.

1991-01-01

Roller element bearings provide the primary mechanical interface between rotating and nonrotating components in the high performance turbomachinery of the Space Shuttle Main Engine (SSME). Knowledge of bearing behavior under various loading and environmental conditions is essential to predicting and understanding the overall behavior of turbopumps, including rotordynamic stability, critical speeds and bearing life. The objective is to develop mathematical models and computer programs to describe the mechanical behavior of ball and cylinder roller bearings under the loading and environmental conditions encountered in the SSME and future high performance rocket engines. This includes characteristics such as nonlinear load/motion relationships, stiffness and damping, rolling element loads for life prediction, and roller and cage stability.

STS-48 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1991-01-01

The STS-48 Space Shuttle Program Mission Report is a summary of the vehicle subsystem operations during the forty-third flight of the Space Shuttle Program and the thirteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-42 (LUT-35); three Space Shuttle main engines (SSME's) (serial numbers 2019, 2031, and 2107 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-046. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each one of the SRB's were designated as 360L018A for the left SRB and 360L018B for the right SRB. The primary objective of the flight was to successfully deploy the Upper Atmospheric Research Satellite (UARS) payload.

CLV First Stage Design, Development, Test and Evaluation

NASA Technical Reports Server (NTRS)

Burt, Richard K.; Brasfield, F.

2006-01-01

The Crew Launch Vehicle (CLV) is an integral part of NASA's Exploration architecture that will provide crew and cargo access to the International Space Station as well as low earth orbit support for lunar missions. Currently in the system definition phase, the CLV is planned to replace the Space Shuttle for crew transport in the post 2010 time frame. It is comprised of a solid rocket booster first stage derived from the current Space Shuttle SRB, a LOX/hydrogen liquid fueled second stage utilizing a derivative of the Space Shuttle Main Engine (SSME) for propulsion, and a Crew Exploration Vehicle (GEV) composed of Command and Service Modules. This paper deals with current DDT&E planning for the CLV first stage solid rocket booster. Described are the current overall point-of-departure design and booster subsystems, systems engineering approach, and milestone schedule requirements.

A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix F: Data base plots for SSME tests 750-120 through 750-200

NASA Technical Reports Server (NTRS)

Coffin, T.

1986-01-01

A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is presented. The data base represents dynamic pressure measurements obtained during single engine hot firing tests of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is also included to estimate spectral trends with SSME power level.

Space Shuttle Main Engine: Thirty Years of Innovation

NASA Technical Reports Server (NTRS)

Jue, F. H.; Hopson, George (Technical Monitor)

2002-01-01

The Space Shuttle Main Engine (SSME) is the first reusable, liquid booster engine designed for human space flight. This paper chronicles the 30-year history and achievements of the SSME from authority to proceed up to the latest flight configuration - the Block 2 SSME.

A History of Space Shuttle Main Engine (SSME) Redline Limits Management

NASA Technical Reports Server (NTRS)

Arnold, Thomas M.

2011-01-01

The Space Shuttle Main Engine (SSME) has several "redlines", which are operational limits designated to preclude a catastrophic shutdown of the SSME. The Space Shuttle Orbiter utilizes a combination of hardware and software to enable or disable the automated redline shutdown capability. The Space Shuttle is launched with the automated SSME redline limits enabled, but there are many scenarios which may result in the manual disabling of the software by the onboard crew. The operational philosophy for manually enabling and disabling the redline limits software has evolved continuously throughout the history of the Space Shuttle Program, due to events such as SSME hardware changes and updates to Space Shuttle contingency abort software. In this paper, the evolution of SSME redline limits management will be fully reviewed, including the operational scenarios which call for manual intervention, and the events that triggered changes to the philosophy. Following this review, improvements to the management of redline limits for future spacecraft will be proposed.

Tripropellant Engine Study

NASA Technical Reports Server (NTRS)

Wheeler, D. B.

1977-01-01

The feasibility of modifying the space shuttle main engine (SSME) for dual mode operation was investigated. Various high power cycle engine configurations derived from the SSME were configurations that will allow sequential burning of LOX/hydrocarbon and LOX/hydrogen were studied in order to identify concepts that make maximum use of SSME hardware and best satisfy the dual mode booster engine system application. Engine cycles were formulated for LOX/RP-1, LOX/CH4, and LOX/C3H8 propellants. Flow rates and operating cycles were established and the adaptability of the major components of the SSME was evaluated.

Health management system for rocket engines

NASA Technical Reports Server (NTRS)

Nemeth, Edward

1990-01-01

The functional framework of a failure detection algorithm for the Space Shuttle Main Engine (SSME) is developed. The basic algorithm is based only on existing SSME measurements. Supplemental measurements, expected to enhance failure detection effectiveness, are identified. To support the algorithm development, a figure of merit is defined to estimate the likelihood of SSME criticality 1 failure modes and the failure modes are ranked in order of likelihood of occurrence. Nine classes of failure detection strategies are evaluated and promising features are extracted as the basis for the failure detection algorithm. The failure detection algorithm provides early warning capabilities for a wide variety of SSME failure modes. Preliminary algorithm evaluation, using data from three SSME failures representing three different failure types, demonstrated indications of imminent catastrophic failure well in advance of redline cutoff in all three cases.

Probabilistic Structural Analysis Methods for select space propulsion system components (PSAM). Volume 2: Literature surveys of critical Space Shuttle main engine components

NASA Technical Reports Server (NTRS)

Rajagopal, K. R.

1992-01-01

The technical effort and computer code development is summarized. Several formulations for Probabilistic Finite Element Analysis (PFEA) are described with emphasis on the selected formulation. The strategies being implemented in the first-version computer code to perform linear, elastic PFEA is described. The results of a series of select Space Shuttle Main Engine (SSME) component surveys are presented. These results identify the critical components and provide the information necessary for probabilistic structural analysis. Volume 2 is a summary of critical SSME components.

General view in the Horizontal Processing Area of the Space ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view in the Horizontal Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view is looking at SSME number 2048 mounted on an SSME engine Handler. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

SRB thermal protection systems materials test results in an arc-heated nitrogen environment

NASA Technical Reports Server (NTRS)

Wojciechowski, C. J.

1979-01-01

The external surface of the Solid Rocket Booster (SRB) will experience imposed thermal and shear environments due to aerodynamic heating and radiation heating during launch, staging and reentry. This report is concerned with the performance of the various TPS materials during the staging maneuver. During staging, the wash from the Space Shuttle Main Engine (SSME) exhust plumes impose severe, short duration, thermal environments on the SRB. Five different SRB TPS materials were tested in the 1 MW Arc Plasma Generator (APG) facility. The maximum simulated heating rate obtained in the APG facility was 248 Btu/sq ft./sec, however, the test duration was such that the total heat was more than simulated. Similarly, some local high shear stress levels of 0.04 psia were not simulated. Most of the SSME plume impingement area on the SRB experiences shear stress levels of 0.02 psia and lower. The shear stress levels on the test specimens were between 0.021 and 0.008 psia. The SSME plume stagnation conditions were also simulated.

Study of weld offset in longitudinally welded SSME HPFTP inlet

NASA Technical Reports Server (NTRS)

Min, J. B.; Spanyer, K. S.; Brunair, R. M.

1992-01-01

Welded joints are an essential part of rocket engine structures such as the Space Shuttle Main Engine (SSME) turbopumps. Defects produced in the welding process can be detrimental to weld performance. Recently, review of the SSME high pressure fuel turbopump (HPFTP) titanium inlet X-rays revealed several weld discrepancies such as penetrameter density issues, film processing discrepancies, weld width discrepancies, porosity, lack of fusion, and weld offsets. Currently, the sensitivity of welded structures to defects is of concern. From a fatigue standpoint, weld offset may have a serious effect since local yielding, in general, aggravates cyclic stress effects. Therefore, the weld offset issue is considered in this report. Using the FEM and beamlike plate approximations, parametric studies were conducted to determine the influence of weld offsets and a variation of weld widths in longitudinally welded cylindrical structures with equal wall thicknesses on both sides of the joint. Following the study, some conclusions are derived for the weld offsets.

Application of advanced coating techniques to rocket engine components

NASA Technical Reports Server (NTRS)

Verma, S. K.

1988-01-01

The materials problem in the space shuttle main engine (SSME) is reviewed. Potential coatings and the method of their application for improved life of SSME components are discussed. A number of advanced coatings for turbine blade components and disks are being developed and tested in a multispecimen thermal fatigue fluidized bed facility at IIT Research Institute. This facility is capable of producing severe strains of the degree present in blades and disk components of the SSME. The potential coating systems and current efforts at IITRI being taken for life extension of the SSME components are summarized.

General view in the Horizontal Processing Area of the Space ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view in the Horizontal Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view is looking at SSME 2052 and 2051 mounted on their SSME Engine Handlers. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Flow Distribution Around the SSME Main Injector Assembly Using Porosity Formulation

NASA Technical Reports Server (NTRS)

Cheng, Gary C.; Chen, Yen-Sen; Wang, Ten-See

1995-01-01

Hot gas turbulent flow distribution around the main injector assembly of the Space Shuttle Main Engine (SSME) and Liquid Oxidizer (LOX) flow distribution through the LOX posts have a great effect on the combustion phenomena inside the main combustion chamber. In order to design a CFD model to be an effective engineering analysis tool with good computational turn- around time (especially for 3-D flow problems) and still maintain good accuracy in describing the flow features, the concept of porosity was employed to describe the effects of blockage and drag force due to the presence of the LOX posts in the turbulent flow field around the main injector assembly of the SSME. 2-D numerical studies were conducted to identify the drag coefficients of the flows both through tube banks and around the shielded posts over a wide range of Reynolds numbers. Empirical, analytical expressions of the drag coefficient as a function of local flow Reynolds number were then deduced. The porosity model was applied to the turbulent flow around the main injector assembly of the SSME, and analyses were performed. The 3-D CFD analysis was divided into three parts, LOX dome, hot gas injector assembly, and hydrogen cavity. The numerical results indicate that the mixture ratio at the downstream of injector face was close to stoichiometric around baffle elements.

Flow Distribution Around the SSME Main Injector Assembly Using Porosity Formulation

NASA Technical Reports Server (NTRS)

Cheng, Gary C.; Chen, Yen-Sen; Wang, Ten-See

1995-01-01

Hot gas turbulent flow distribution around the main injector assembly of the Space Shuttle Main Engine (SSME) and Liquid Oxidizer (LOX) flow distribution through the LOX posts have a great effect on the combustion phenomena inside the main combustion chamber. In order to design a CFD model to be an effective engineering analysis tool with good computational turn-around time (especially for 3-D flow problems) and still maintain good accuracy in describing the flow features, the concept of porosity was employed to describe the effects of blockage and drag force due to the presence of the LOX posts in the turbulent flow field around the main injector assembly of the SSME. 2-D numerical studies were conducted to identify the drag coefficients of the flows both through tube banks and around the shielded posts over a wide range of Reynolds numbers. Empirical, analytical expressions of the drag coefficient as a function of local flow Reynolds number were then deduced. The porosity model was applied to the turbulent flow around the main injector assembly of the SSME, and analyses were performed. The 3-D CFD analysis was divided into three parts, LOX dome, hot gas injector assembly, and hydrogen cavity. The numerical results indicate that the mixture ratio at the downstream of injector face was close to stoichiometric around baffle elements.

Space Shuttle Main Engine Joint Data List Applying Today's Desktop Technologies to Facilitate Engine Processing

NASA Technical Reports Server (NTRS)

Jacobs, Kenneth; Drobnick, John; Krell, Don; Neuhart, Terry; McCool, A. (Technical Monitor)

2001-01-01

Boeing-Rocketdyne's Space Shuttle Main Engine (SSME) is the world's first large reusable liquid rocket engine. The space shuttle propulsion system has three SSMEs, each weighing 7,400 lbs and providing 470,000 lbs of thrust at 100% rated power level. To ensure required safety and reliability levels are achieved with the reusable engines, each SSME is partially disassembled, inspected, reassembled, and retested at Kennedy Space Center between each flight. Maintenance processing must be performed very carefully to replace any suspect components, maintain proper engine configuration, and avoid introduction of contaminants that could affect performance and safety. The long service life, and number, complexity, and pedigree of SSME components makes logistics functions extremely critical. One SSME logistics challenge is documenting the assembly and disassembly of the complex joint configurations. This data (joint nomenclature, seal and fastener identification and orientation, assembly sequence, fastener torques, etc.) must be available to technicians and engineers during processing. Various assembly drawings and procedures contain this information, but in this format the required (practical) joint data can be hard to find, due to the continued use of archaic engineering drawings and microfilm for field site use. Additionally, the release system must traverse 2,500 miles between design center and field site, across three time zones, which adds communication challenges and time lags for critical engine configuration data. To aid in information accessibility, a Joint Data List (JDL) was developed that allows efficient access to practical joint data. The published JDL has been a very useful logistics product, providing illustrations and information on the latest SSME configuration. The JDL identifies over 3,350 unique parts across seven fluid systems, over 300 joints, times two distinct engine configurations. The JDL system was recently converted to a web-based, navigable electronic manual that contains all the required data and illustrations in expanded view format using standard PC products (Word, Excel, PDF, Photoshop). The logistics of accurately releasing this information to field personnel was greatly enhanced via the utilization of common office products to produce a more user-friendly format than was originally developed under contract to NASA. This was done without reinventing the system, which would be cost prohibitive on a program of this maturity. The brunt of the joint part tracking is done within the logistics organization and disseminated to all field sites, without duplicating effort at each site. The JDL is easily accessible across the country via the NASA intranet directly at the SSME workstand. The advent of this logistics data product has greatly enhanced the reliability of tracking dynamic changes to the SSME and greatly reduces engineering change turnaround time and potential for errors. Since the inception of the JDL system in 1997, no discrepant parts have propagated to engine assembly operations. This presentation focuses on the challenges overcome and the techniques used to apply today's desktop technologies to an existing logistics data source.

Space Shuttle Main Engine Low Pressure Oxidizer Turbo-Pump Inducer Dynamic Environment Characterization through Water Model and Hot-Fire Testing

NASA Technical Reports Server (NTRS)

Arellano, Patrick; Patton, Marc; Schwartz, Alan; Stanton, David

2006-01-01

The Low Pressure Oxidizer Turbopump (LPOTP) inducer on the Block II configuration Space Shuttle Main Engine (SSME) experienced blade leading edge ripples during hot firing. This undesirable condition led to a minor redesign of the inducer blades. This resulted in the need to evaluate the performance and the dynamic environment of the redesign, relative to the current configuration, as part of the design acceptance process. Sub-scale water model tests of the two inducer configurations were performed, with emphasis on the dynamic environment due to cavitation induced vibrations. Water model tests were performed over a wide range of inlet flow coefficient and pressure conditions, representative of the scaled operating envelope of the Block II SSME, both in flight and in ground hot-fire tests, including all power levels. The water test hardware, facility set-up, type and placement of instrumentation, the scope of the test program, specific test objectives, data evaluation process and water test results that characterize and compare the two SSME LPOTP inducers are discussed. In addition, dynamic characteristics of the two water models were compared to hot fire data from specially instrumented ground tests. In general, good agreement between the water model and hot fire data was found, which confirms the value of water model testing for dynamic characterization of rocket engine turbomachinery.

STS-51 pad abort. OV103-engine 2033 (ME-2) fuel flowmeter sensor open circuit

NASA Technical Reports Server (NTRS)

1993-01-01

The STS-51 initial launch attempt of Discovery (OV-103) was terminated on KSC launch pad 39B on 12 Aug. 1993 at 9:12 AM E.S.T. due to a sensor redundancy failure in the liquid hydrogen system of ME-2 (Engine 2033). The event description and time line are summarized. Propellant loading was initiated on 12 Aug. 1993 at 12:00 AM EST. All space shuttle main engine (SSME) chill parameters and Launch Commit Criteria (LCC) were nominal. At engine start plus 1.34 seconds a Failure Identification (FID) was posted against Engine 2033 for exceeding the 1800 spin intra-channel (A1-A2) Fuel Flowrate sensor channel qualification limit. The engine was shut down at 1.50 seconds followed by Engines 2032 and 2030. All shut down sequences were nominal and the mission was safely aborted. SSME Avionics hardware and software performed nominally during the incident. A review of vehicle data table (VDT) data and controller software logic revealed no failure indications other than the single FID 111-101, Fuel Flowrate Intra-Channel Test Channel A disqualification. Software logic was executed according to requirements and there was no anomalous controller software operation. Immediately following the abort, a Rocketdyne/NASA failure investigation team was assembled. The team successfully isolated the failure cause to an open circuit in a Fuel Flowrate Sensor. This type of failure has occurred eight previous times in ground testing. The sensor had performed acceptably on three previous flights of the engine and SSME flight history shows 684 combined fuel flow rate sensor channel flights without failure. The disqualification of an Engine 2 (SSME No. 2033) Fuel Flowrate sensor channel was a result of an instrumentation failure and not engine performance. All other engine operations were nominal. This disqualification resulted in an engine shutdown and safe sequential shutdown of all three engines prior to ignition of the solid boosters.

SSME Condition Monitoring Using Neural Networks and Plume Spectral Signatures

NASA Technical Reports Server (NTRS)

Hopkins, Randall; Benzing, Daniel

1996-01-01

For a variety of reasons, condition monitoring of the Space Shuttle Main Engine (SSME) has become an important concern for both ground tests and in-flight operation. The complexities of the SSME suggest that active, real-time condition monitoring should be performed to avoid large-scale or catastrophic failure of the engine. In 1986, the SSME became the subject of a plume emission spectroscopy project at NASA's Marshall Space Flight Center (MSFC). Since then, plume emission spectroscopy has recorded many nominal tests and the qualitative spectral features of the SSME plume are now well established. Significant discoveries made with both wide-band and narrow-band plume emission spectroscopy systems led MSFC to develop the Optical Plume Anomaly Detection (OPAD) system. The OPAD system is designed to provide condition monitoring of the SSME during ground-level testing. The operational health of the engine is achieved through the acquisition of spectrally resolved plume emissions and the subsequent identification of abnormal emission levels in the plume indicative of engine erosion or component failure. Eventually, OPAD, or a derivative of the technology, could find its way on to an actual space vehicle and provide in-flight engine condition monitoring. This technology step, however, will require miniaturized hardware capable of processing plume spectral data in real-time. An objective of OPAD condition monitoring is to determine how much of an element is present in the SSME plume. The basic premise is that by knowing the element and its concentration, this could be related back to the health of components within the engine. For example, an abnormal amount of silver in the plume might signify increased wear or deterioration of a particular bearing in the engine. Once an anomaly is identified, the engine could be shut down before catastrophic failure occurs. Currently, element concentrations in the plume are determined iteratively with the help of a non-linear computer code called SPECTRA, developed at the USAF Arnold Engineering Development Center. Ostensibly, the code produces intensity versus wavelength plots (i.e., spectra) when inputs such as element concentrations, reaction temperature, and reaction pressure are provided. However, in order to provide a higher-level analysis, element concentration is not specified explicitly as an input. Instead, two quantum variables, number density and broadening parameter, are used. Past experience with OPAD data analysis has revealed that the region of primary interest in any SSME plume spectrum lies in the wavelength band of 3300 A to 4330 A. Experience has also revealed that some elements, such as iron, cobalt and nickel, cause multiple peaks over the chosen wavelength range whereas other elements (magnesium, for example) have a few, relatively isolated peaks in the chosen wavelength range. Iteration with SPECTRA as a part of OPAD data analysis is an incredibly labor intensive task and not one to be performed by hand. What is really needed is the "inverse" of the computer code but the mathematical model for the inverse mapping is tenuous at best. However, building generalized models based upon known input/output mappings while ignoring details of the governing physical model is possible using neural networks. Thus the objective of the research project described herein was to quickly and accurately predict combustion temperature and element concentrations (i.e., number density and broadening parameter) from a given spectrum using a neural network. In other words, a neural network had to be developed that would provide a generalized "inverse" of the computer code SPECTRA.

General view of the shop floor looking north in the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the shop floor looking north in the Vertical Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. SSME number 2061's nozzle is being inspected by an SSME technician in the foreground. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5

NASA Technical Reports Server (NTRS)

Anderson, P. J.; Nussbaum, P.; Gustafson, G.

1984-01-01

The objective of the research project described is to define and demonstrate methods to advance the state of the art of pressure sensors for the space shuttle main engine (SSME). Silicon piezoresistive technology was utilized in completing tasks: generation and testing of three transducer design concepts for solid state applications; silicon resistor characterization at cryogenic temperatures; experimental chip mounting characterization; frequency response optimization and prototype design and fabrication. Excellent silicon sensor performance was demonstrated at liquid nitrogen temperature. A silicon resistor ion implant dose was customized for SSME temperature requirements. A basic acoustic modeling software program was developed as a design tool to evaluate frequency response characteristics.

Cold flow testing of the Space Shuttle Main Engine high pressure fuel turbine model

NASA Technical Reports Server (NTRS)

Hudson, Susan T.; Gaddis, Stephen W.; Johnson, P. D.; Boynton, James L.

1991-01-01

In order to experimentally determine the performance of the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) turbine, a 'cold' air flow turbine test program was established at NASA's Marshall Space Flight Center. As part of this test program, a baseline test of Rocketdyne's HPFTP turbine has been completed. The turbine performance and turbine diagnostics such as airfoil surface static pressure distributions, static pressure drops through the turbine, and exit swirl angles were investigated at the turbine design point, over its operating range, and at extreme off-design points. The data was compared to pretest predictions with good results. The test data has been used to improve meanline prediction codes and is now being used to validate various three-dimensional codes. The data will also be scaled to engine conditions and used to improve the SSME steady-state performance model.

General view of a Space Shuttle Main Engine (SSME) mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping diagonally across the top of the assembly and connecting to the High-Pressure Fuel Turbopump, the Low-Pressure Oxidizer Turbopump (LPOTP) located center right of the assembly and the LPOTP Discharge Duct looping around from the pump to the underside of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

General view in the Vertical Processing Area of the Space ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view in the Vertical Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view shows a SSME Rotating Sling in the foreground right and SSME 2056 in the foreground and SSMEs 2050, 2062 and 2054 in succession towards the background. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Impact of uncertainty on modeling and testing

NASA Technical Reports Server (NTRS)

Coleman, Hugh W.; Brown, Kendall K.

1995-01-01

A thorough understanding of the uncertainties associated with the modeling and testing of the Space Shuttle Main Engine (SSME) Engine will greatly aid decisions concerning hardware performance and future development efforts. This report will describe the determination of the uncertainties in the modeling and testing of the Space Shuttle Main Engine test program at the Technology Test Bed facility at Marshall Space Flight Center. Section 2 will present a summary of the uncertainty analysis methodology used and discuss the specific applications to the TTB SSME test program. Section 3 will discuss the application of the uncertainty analysis to the test program and the results obtained. Section 4 presents the results of the analysis of the SSME modeling effort from an uncertainty analysis point of view. The appendices at the end of the report contain a significant amount of information relative to the analysis, including discussions of venturi flowmeter data reduction and uncertainty propagation, bias uncertainty documentations, technical papers published, the computer code generated to determine the venturi uncertainties, and the venturi data and results used in the analysis.

Investigation of the feasibility of temperature profiling optical diagnostics in the SSME fuel pre-burner

NASA Technical Reports Server (NTRS)

Shirley, J. A.

1983-01-01

Results of an analytical investigation to determine the feasibility of temperature profiling in the space shuttle main engine (SSME) fuel preburner are presented. In this application it is desirable to measure temperature in the preburner combustor with a remote, nonintrusive optical technique. Several techniques using laser excitation were examined with a consideration of the constraints imposed by optical access in the fuel preburner and the problems associated with operation near the functioning space shuttle engine. The potential performance of practical diagnostic systems based on spontaneous Raman backscattering, laser induced fluorescence, and coherent anti-Stokes Raman spectroscopy were compared analytically. A system using collection of spontaneous Raman backscattering excited by a remotely located 5 to 10 watt laser propagated to the SSME through a small diameter optical fiber was selected as the best approach. Difficulties normally associated with Raman scattering: weak signal strength and interference due to background radiation are not expected to be problematic due to the very high density in this application, and the low flame luminosity expected in the fuel rich hydrogen oxygen flame.

KSC-04pd1646

NASA Image and Video Library

2004-08-03

KENNEDY SPACE CENTER, FLA. - In the Space Shuttle Main Engine (SSME) Processing Facility, Boeing-Rocketdyne crane operator Joe Ferrante (left) lowers SSME 2058, the first SSME fully assembled at KSC, onto an engine stand with the assistance of other technicians on his team. The engine is being moved from its vertical work stand into a horizontal position in preparation for shipment to NASA’s Stennis Space Center in Mississippi to undergo a hot fire acceptance test. It is the first of five engines to be fully assembled on site to reach the desired number of 15 engines ready for launch at any given time in the Space Shuttle program. A Space Shuttle has three reusable main engines. Each is 14 feet long, weighs about 7,800 pounds, is seven-and-a-half feet in diameter at the end of its nozzle, and generates almost 400,000 pounds of thrust. Historically, SSMEs were assembled in Canoga Park, Calif., with post-flight inspections performed at KSC. Both functions were consolidated in February 2002. The Rocketdyne Propulsion and Power division of The Boeing Co. manufactures the engines for NASA.

KSC-04pd1645

NASA Image and Video Library

2004-08-03

KENNEDY SPACE CENTER, FLA. - In the Space Shuttle Main Engine (SSME) Processing Facility, Boeing-Rocketdyne crane operator Joe Ferrante (second from right) lifts SSME 2058, the first SSME fully assembled at KSC, with the assistance of other technicians on his team. The engine is being lifted from its vertical work stand into a horizontal position in preparation for shipment to NASA’s Stennis Space Center in Mississippi to undergo a hot fire acceptance test. It is the first of five engines to be fully assembled on site to reach the desired number of 15 engines ready for launch at any given time in the Space Shuttle program. A Space Shuttle has three reusable main engines. Each is 14 feet long, weighs about 7,800 pounds, is seven-and-a-half feet in diameter at the end of its nozzle, and generates almost 400,000 pounds of thrust. Historically, SSMEs were assembled in Canoga Park, Calif., with post-flight inspections performed at KSC. Both functions were consolidated in February 2002. The Rocketdyne Propulsion and Power division of The Boeing Co. manufactures the engines for NASA.

Progress in the measurement of SSME turbine heat flux with plug-type sensors

NASA Technical Reports Server (NTRS)

Liebert, Curt H.

1991-01-01

Data reduction was completed for tests of plug-type heat flux sensors (gauges) in a turbine blade thermal cycling tester (TBT) that is located at NASA/Marshall Space Flight Center, and a typical gauge is illustrated. This is the first time that heat flux has been measured in a Space Shuttle Main Engine (SSME) Turbopump Turbine environment. The development of the concept for the gauge was performed in a heat flux measurement facility at Lewis. In this facility, transient and steady state absorbed surface heat flux information was obtained from transient temperature measurements taken at points within the gauge. A schematic of the TBT is presented, and plots of the absorbed surface heat flux measured on the three blades tested in the TBT are presented. High quality heat flux values were measured on all three blades. The experiments demonstrated that reliable and durable gauges can be repeatedly fabricated into the airfoils. The experiment heat flux data are being used for verification of SSME analytical stress, boundary layer, and heat transfer design models. Other experimental results and future plans are also presented.

KSC-04PD-1648

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Space Shuttle Main Engine (SSME) Processing Facility, Boeing-Rocketdyne quality inspector Nick Grimm (center) monitors the work of technicians on his team as they lower SSME 2058, the first SSME fully assembled at KSC, onto an engine stand. The engine is being placed into a horizontal position in preparation for shipment to NASAs Stennis Space Center in Mississippi to undergo a hot fire acceptance test. It is the first of five engines to be fully assembled on site to reach the desired number of 15 engines ready for launch at any given time in the Space Shuttle program. A Space Shuttle has three reusable main engines. Each is 14 feet long, weighs about 7,800 pounds, is seven-and-a-half feet in diameter at the end of its nozzle, and generates almost 400,000 pounds of thrust. Historically, SSMEs were assembled in Canoga Park, Calif., with post-flight inspections performed at KSC. Both functions were consolidated in February 2002. The Rocketdyne Propulsion and Power division of The Boeing Co. manufactures the engines for NASA.

A function approximation approach to anomaly detection in propulsion system test data

NASA Technical Reports Server (NTRS)

Whitehead, Bruce A.; Hoyt, W. A.

1993-01-01

Ground test data from propulsion systems such as the Space Shuttle Main Engine (SSME) can be automatically screened for anomalies by a neural network. The neural network screens data after being trained with nominal data only. Given the values of 14 measurements reflecting external influences on the SSME at a given time, the neural network predicts the expected nominal value of a desired engine parameter at that time. We compared the ability of three different function-approximation techniques to perform this nominal value prediction: a novel neural network architecture based on Gaussian bar basis functions, a conventional back propagation neural network, and linear regression. These three techniques were tested with real data from six SSME ground tests containing two anomalies. The basis function network trained more rapidly than back propagation. It yielded nominal predictions with, a tight enough confidence interval to distinguish anomalous deviations from the nominal fluctuations in an engine parameter. Since the function-approximation approach requires nominal training data only, it is capable of detecting unknown classes of anomalies for which training data is not available.

KSC-04pd1648

NASA Image and Video Library

2004-08-03

KENNEDY SPACE CENTER, FLA. - In the Space Shuttle Main Engine (SSME) Processing Facility, Boeing-Rocketdyne quality inspector Nick Grimm (center) monitors the work of technicians on his team as they lower SSME 2058, the first SSME fully assembled at KSC, onto an engine stand. The engine is being placed into a horizontal position in preparation for shipment to NASA’s Stennis Space Center in Mississippi to undergo a hot fire acceptance test. It is the first of five engines to be fully assembled on site to reach the desired number of 15 engines ready for launch at any given time in the Space Shuttle program. A Space Shuttle has three reusable main engines. Each is 14 feet long, weighs about 7,800 pounds, is seven-and-a-half feet in diameter at the end of its nozzle, and generates almost 400,000 pounds of thrust. Historically, SSMEs were assembled in Canoga Park, Calif., with post-flight inspections performed at KSC. Both functions were consolidated in February 2002. The Rocketdyne Propulsion and Power division of The Boeing Co. manufactures the engines for NASA.

Closeup side view of Space Shuttle Main Engine (SSME) 2059 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up side view of Space Shuttle Main Engine (SSME) 2059 mounted in a SSME Engine Handler near the Drying Area in the High Bay section of the SSME Processing Facility. The prominent features of the SSME in this view are the hot-gas expansion nozzle extending from the approximate image center toward the image right. The main-engine components extend from the approximate image center toward image right until it meets up with the mount for the SSME Engine Handler. The engine is rotated to a position where the major components in the view are the Low-Pressure Fuel Turbopump Discharge Duct with reflective foil insulation on the upper side of the engine, the Low-Pressure Oxidizer Turbopump and its Discharge Duct on the right side of the engine assembly extending itself down and wrapping under the bottom side of the assembly to the High-Pressure Oxidizer Turbopump pump. The High-Pressure Oxidizer Turbopump Discharge Duct exists the turbopump and extends up to the top side of the assembly where it enters the main oxidizer valve. The sphere on the lower side of the engine assembly is an accumulator that is part of the SSMEs POGO suppression system. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Framework for a space shuttle main engine health monitoring system

NASA Technical Reports Server (NTRS)

Hawman, Michael W.; Galinaitis, William S.; Tulpule, Sharayu; Mattedi, Anita K.; Kamenetz, Jeffrey

1990-01-01

A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available.

STS-42 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1992-01-01

The STS-42 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-fifth flight of the Space Shuttle Program and the fourteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-52 (LWT-45); three Space Shuttle main engines (SSME's), which were serial numbers 2026, 2022, and 2027 in positions 1, 2, and 3, respectively; and two Solid Rocket Boosters (SRB's) designated as BI-048. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each one of the SRB's were designated as 360L020A for the left SRM and 360Q020B for the right SRM. The primary objective of the STS-42 mission was to complete the objectives of the first International Microgravity Laboratory (IML-1). Secondary objectives were to perform all operations necessary to support the requirements of the following: Gelation of Sols: Applied Microgravity Research (GOSAMR); Student Experiment 81-09 (Convection in Zero Gravity); Student Experiment 83-02 (Capillary Rise of Liquid Through Granular Porous Media); the Investigation into Polymer Membrane Processing (IPMP); the Radiation Monitoring Equipment-3 (RME-3); and Get-Away Special (GAS) payloads carried on the GAS Beam Assembly.

STS-42 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W.

1992-02-01

The STS-42 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-fifth flight of the Space Shuttle Program and the fourteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Discovery vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-52 (LWT-45); three Space Shuttle main engines (SSME's), which were serial numbers 2026, 2022, and 2027 in positions 1, 2, and 3, respectively; and two Solid Rocket Boosters (SRB's) designated as BI-048. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each one of the SRB's were designated as 360L020A for the left SRM and 360Q020B for the right SRM. The primary objective of the STS-42 mission was to complete the objectives of the first International Microgravity Laboratory (IML-1). Secondary objectives were to perform all operations necessary to support the requirements of the following: Gelation of Sols: Applied Microgravity Research (GOSAMR); Student Experiment 81-09 (Convection in Zero Gravity); Student Experiment 83-02 (Capillary Rise of Liquid Through Granular Porous Media); the Investigation into Polymer Membrane Processing (IPMP); the Radiation Monitoring Equipment-3 (RME-3); and Get-Away Special (GAS) payloads carried on the GAS Beam Assembly.

Using neural networks to assist in OPAD data analysis

NASA Technical Reports Server (NTRS)

Whitaker, Kevin W.

1993-01-01

The space shuttle main engine (SSME) became the subject of plume emission spectroscopy in 1986 when researchers from NASA-Marshall Space Flight Center (MSFC), Arnold Engineering Development Center (AEDC), and Rocketdyne went to the SSME test stands at the NASA-Stennis Space Center and at Rocketdyne's Santa Susan Field Laboratory to optically observe the plume. Since then, plume spectral acquisitions have recorded many nominal tests and the qualitative spectral features of the SSME plume are now well established. Significant discoveries made with both wide-band and narrow-band plume emission spectroscopy systems led MSFC to promote the Optical Plume Anomaly Detection (OPAD) program with a goal of instrumenting all SSME test stands with customized spectrometer systems. A prototype OPAD system is now installed on the SSME Technology Test Bed (TTB) at MSFC. The OPAD system instrumentation consists of a broad-band, optical multiple-channel analyzer (OMA) and a narrow-band device called a polychrometer. The OMA is a high-resolution (1.5-2.0 Angstroms) 'super-spectrometer' covering the near-ultraviolet to near-infrared waveband (2800-7400 Angstroms), providing two scans per second. The polychrometer consists of sixteen narrow-band radiometers: fourteen monitoring discrete wavelengths of health and condition monitoring elements and two dedicated to monitoring background emissions. All sixteen channels are capable of providing 500 samples per second. To date, the prototype OPAD system has been used during 43 SSME firings on the TTB, collecting well over 250 megabytes of plume spectral data. One goal of OPAD data analysis is to determine interatively with the help of a computer code, SPECTRA4, developed at AEDC. Experience has shown that iteration with SPECTRA4 is an incredibly labor intensive task and not one to be performed by band. What is really needed is the 'inverse' of SPECTRA4 but the mathematical model for this inverse mapping is tenuous at best. However, the robustness of PSECTRA4 run in the 'forward' direction means that accurate input/output mappings can be obtained. If the mappings were inverted (i.e., input becomes output and output becomes input) then an 'inverse' of SPECTRA4 would be at hand but the 'model' would be specific to the data utilized and would in no way be general. Building a generalized model based upon known input/output mappings while ignoring the details of the governing physical model is possible through the use of a neural network. The research investigation described involves the development of a neural network to provide a generalized 'inverse' of SPECTRA4. The objectives of the research were to design an appropriate neural network architecture, train the network, and then evaluate its performance.

General view of a Space Shuttle Main Engine (SSME) mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent feature in this view is the Expansion Nozzle . The rings that loop around the nozzle, vertically in this view, add structural stability to the nozzle walls and are referred to Hatbands. The ring on the left most edge of the nozzle is the Coolant Inlet Manifold. The tubes that branch off and connect to the manifold are Coolant Transfer Ducts and the tubes that terminate with a visible opening at the manifold are Drain Lines. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Closeup view of a Space Shuttle Main Engine (SSME) mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent feature in this view is the Expansion Nozzle . The rings that loop around the nozzle, vertically in this view, add structural stability to the nozzle walls and are referred to Hatbands. The ring on the left most edge of the nozzle is the Coolant Inlet Manifold. The tubes that branch off and connect to the manifold are Coolant Transfer Ducts and the tubes that terminate with a visible opening at the manifold are Drain Lines. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

General view of a Space Shuttle Main Engine (SSME) mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Fuel Turbopump Discharge Duct looping around the right side and underneath the assembly, the High-Pressure Fuel Turbopump located on the lower left portion of the assembly, the Engine Controller and Main Fuel Valve Hydraulic Actuator located on the upper portion of the assembly and the Low-Pressure Oxidizer Turbopump Discharge Duct at the top of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

General view of a Space Shuttle Main Engine (SSME) mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of a Space Shuttle Main Engine (SSME) mounted on an SSME engine handler, taken in the SSME Processing Facility at Kennedy Space Center. The most prominent features of the engine assembly in this view are the Low-Pressure Oxidizer Turbopump Discharge Duct looping around the right side of the engine assembly then turning in and connecting to the High-Pressure Oxidizer Turbopump. The sphere in the approximate center of the assembly is the POGO System Accumulator, the Engine Controller is located on the bottom and slightly left of the center of the Engine Assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Studies and analyses of the space shuttle main engine

NASA Technical Reports Server (NTRS)

Tischer, Alan E.; Glover, R. C.

1987-01-01

The primary objectives were to: evaluate ways to maximize the information yield from the current Space Shuttle Main Engine (SSME) condition monitoring sensors, identify additional sensors or monitoring capabilities which would significantly improve SSME data, and provide continuing support of the Main Engine Cost/Operations (MECO) model. In the area of SSME condition monitoring, the principal tasks were a review of selected SSME failure data, a general survey of condition monitoring, and an evaluation of the current engine monitoring system. A computerized data base was developed to assist in modeling engine failure information propagations. Each of the above items is discussed in detail. Also included is a brief discussion of the activities conducted in support of the MECO model.

Structural response of SSME turbine blade airfoils

NASA Technical Reports Server (NTRS)

Arya, V. K.; Abdul-Aziz, A.; Thompson, R. L.

1988-01-01

Reusable space propulsion hot gas-path components are required to operate under severe thermal and mechanical loading conditions. These operating conditions produce elevated temperature and thermal transients which results in significant thermally induced inelastic strains, particularly, in the turbopump turbine blades. An inelastic analysis for this component may therefore be necessary. Anisotropic alloys such as MAR M-247 or PWA-1480 are being considered to meet the safety and durability requirements of this component. An anisotropic inelastic structural analysis for an SSME fuel turbopump turbine blade was performed. The thermal loads used resulted from a transient heat transfer analysis of a turbine blade. A comparison of preliminary results from the elastic and inelastic analyses is presented.

Close-up of SSME

NASA Technical Reports Server (NTRS)

1994-01-01

A close-up view of a Space Shuttle Main Engine during a test at the John C. Stennis Space Center shows how the engine is gimballed, or rotated, to evaluate the performance of its components under simulated flight conditions.

Time-Dependent Simulations of Incompressible Flow in a Turbopump Using Overset Grid Approach

NASA Technical Reports Server (NTRS)

Kiris, Cetin; Kwak, Dochan

2001-01-01

This viewgraph presentation provides information on mathematical modelling of the SSME (space shuttle main engine). The unsteady SSME-rig1 start-up procedure from the pump at rest has been initiated by using 34.3 million grid points. The computational model for the SSME-rig1 has been completed. Moving boundary capability is obtained by using DCF module in OVERFLOW-D. MPI (Message Passing Interface)/OpenMP hybrid parallel code has been benchmarked.

Understanding and Resolution of the Block 2 SSME, STS-104 Engine Shutdown Pressure Surge In-flight Anomaly

NASA Technical Reports Server (NTRS)

Greene, William D.; Kynard, Michael H.; Tiller, Bruce K. (Technical Monitor)

2002-01-01

STS-104, launched July 2001, marked the first flight of a single Block 2 Space Shuttle Main Engine (SSME). This new configuration of the SSME is the culmination of well over a decade of gradual engine system upgrades. The launch and mission were a success. However, in the process of post-launch data analysis a Main Propulsion System (MPS) anomaly was noted and tied directly to the shutdown of the Block 2 SSME. An investigation into this anomaly was organized across NASA facilities and across the various hardware component contractors. This paper is a very brief summary of the eventual understanding of the root causes of the anomaly and the process whereby an appropriate mitigation action was proposed. An analytical model of the High Pressure Fuel Pump (HPFP) and the low pressure fuel system of the SSME is presented to facilitate the presentation of this summary. The proposed mitigation action is discussed and, with the launch of STS-108 in November 2001, successfully demonstrated under flight conditions.

Thin film thermocouples for high temperature turbine application

NASA Technical Reports Server (NTRS)

Martin, Lisa C.

1991-01-01

The objective is to develop thin film thermocouples (TFTC) for Space Shuttle Main Engine (SSME) components such as the high pressure fuel turbopump (HPFTP) blades and to test TFTC survivability and durability in the SSME environment. The purpose for developing TFTC's for SSME components is to obtain blade temperatures for computational models developed for fluid mechanics and structures. The TFTC must be able to withstand the presence of high temperature, high pressure hydrogen as well as a severe thermal transient due to a cryogenic to combustion temperature change. The TFTC's will eventually be installed and tested on SSME propulsion system components in the SSME test bed engine. The TFTC's were successfully fabricated on flat coupons of MAR-M 246 (Hf+), which is the superalloy material used for HPFTP turbine blades. The TFTC's fabricated on flat coupons survived thermal shock cycling as well as testing in a heat flux measurement facility which provided a rapid thermal transient. The same fabrication procedure was used to deposit TFTC's on HPFTP first stage rotor blades. Other results from the experiments are presented, and future testing plans are discussed.

Shuttle Propulsion Overview - The Design Challenges

NASA Technical Reports Server (NTRS)

Owen, James W.

2011-01-01

The major elements of the Space Shuttle Main Propulsion System include two reusable solid rocket motors integrated into recoverable solid rocket boosters, an expendable external fuel and oxidizer tank, and three reusable Space Shuttle Main Engines. Both the solid rocket motors and space shuttle main engines ignite prior to liftoff, with the solid rocket boosters separating about two minutes into flight. The external tank separates, about eight and a half minutes into the flight, after main engine shutdown and is safely expended in the ocean. The SSME's, integrated into the Space Shuttle Orbiter aft structure, are reused after post landing inspections. The configuration is called a stage and a half as all the propulsion elements are active during the boost phase, with only the SSME s continuing operation to achieve orbital velocity. Design and performance challenges were numerous, beginning with development work in the 1970's. The solid rocket motors were large, and this technology had never been used for human space flight. The SSME s were both reusable and very high performance staged combustion cycle engines, also unique to the Space Shuttle. The multi body side mount configuration was unique and posed numerous integration and interface challenges across the elements. Operation of the system was complex and time consuming. This paper describes the design challenges and key areas where the design evolved during the program.

Incorporating engine health monitoring capability into the SSME Block II controller

NASA Astrophysics Data System (ADS)

Clarke, James W.; Copa, Roderick J.

An account is given of the architecture of the SSME's Block II controller's architecture, its incorporation of smart input electronics (SIE), and the potential benefits of this technology in SSME health-monitoring capabilities. SIE allows the Block II controller to conduct its control functions while simultaneously furnishing the computational capabilities and sensor input interface for any newly defined health-monitoring functions. It is expected that the SIE technology may be directly transferred to any follow-on engine design.

Programs for Testing an SSME-Monitoring System

NASA Technical Reports Server (NTRS)

Lang, Andre; Cecil, Jimmie; Heusinger, Ralph; Freestone, Kathleen; Blue, Lisa; Wilkerson, DeLisa; McMahon, Leigh Anne; Hall, Richard B.; Varnavas, Kosta; Smith, Keary;

Redesign and Test of an SSME Turbopump for the Large Throat Main Combustion Chamber

NASA Technical Reports Server (NTRS)

Lunde, K. J.; Lee, G. A.; Eastland, A. H.; Rojas, L.

1994-01-01

The preburner oxidizer turbopump for the Space Shuttle Main Engine (SSME) was successfully redesigned for use with the Large Throat Main Combustion Chamber (LTMCC) and tested in air utilizing rapid prototyping. The redesign increases the SSME's operating range with the current Main Combustion Chamber (MCC) while achieving full operational range with the LTMCC. The use of rapid prototyping and air testing to validate the redesign demonstrated the ability to design, fabricate and test designs rapidly and at a very low cost.

Space shuttle requirements/configuration evolution

NASA Technical Reports Server (NTRS)

Andrews, E. P.

1991-01-01

Space Shuttle chronology; Space Shuttle comparison; Cost comparison; Performance; Program ground rules; Sizing criteria; Crew/passenger provisions; Space Shuttle Main Engine (SSME) characteristics; Space Shuttle program milestones; and Space Shuttle requirements are outlined. This presentation is represented by viewgraphs.

Development of an intelligent diagnostic system for reusable rocket engine control

NASA Technical Reports Server (NTRS)

Anex, R. P.; Russell, J. R.; Guo, T.-H.

1991-01-01

A description of an intelligent diagnostic system for the Space Shuttle Main Engines (SSME) is presented. This system is suitable for incorporation in an intelligent controller which implements accommodating closed-loop control to extend engine life and maximize available performance. The diagnostic system architecture is a modular, hierarchical, blackboard system which is particularly well suited for real-time implementation of a system which must be repeatedly updated and extended. The diagnostic problem is formulated as a hierarchical classification problem in which the failure hypotheses are represented in terms of predefined data patterns. The diagnostic expert system incorporates techniques for priority-based diagnostics, the combination of analytical and heuristic knowledge for diagnosis, integration of different AI systems, and the implementation of hierarchical distributed systems. A prototype reusable rocket engine diagnostic system (ReREDS) has been implemented. The prototype user interface and diagnostic performance using SSME test data are described.

Parallel Unsteady Turbopump Simulations for Liquid Rocket Engines

NASA Technical Reports Server (NTRS)

Kiris, Cetin C.; Kwak, Dochan; Chan, William

2000-01-01

This paper reports the progress being made towards complete turbo-pump simulation capability for liquid rocket engines. Space Shuttle Main Engine (SSME) turbo-pump impeller is used as a test case for the performance evaluation of the MPI and hybrid MPI/Open-MP versions of the INS3D code. Then, a computational model of a turbo-pump has been developed for the shuttle upgrade program. Relative motion of the grid system for rotor-stator interaction was obtained by employing overset grid techniques. Time-accuracy of the scheme has been evaluated by using simple test cases. Unsteady computations for SSME turbo-pump, which contains 136 zones with 35 Million grid points, are currently underway on Origin 2000 systems at NASA Ames Research Center. Results from time-accurate simulations with moving boundary capability, and the performance of the parallel versions of the code will be presented in the final paper.

Balancing low cost with reliable operation in the rotordynamic design of the ALS Liquid Hydrogen Fuel Turbopump

NASA Technical Reports Server (NTRS)

Greenhill, L. M.

1990-01-01

The Air Force/NASA Advanced Launch System (ALS) Liquid Hydrogen Fuel Turbopump (FTP) has primary design goals of low cost and high reliability, with performance and weight having less importance. This approach is atypical compared with other rocket engine turbopump design efforts, such as on the Space Shuttle Main Engine (SSME), which emphasized high performance and low weight. Similar to the SSME turbopumps, the ALS FTP operates supercritically, which implies that stability and bearing loads strongly influence the design. In addition, the use of low cost/high reliability features in the ALS FTP such as hydrostatic bearings, relaxed seal clearances, and unshrouded turbine blades also have a negative influence on rotordynamics. This paper discusses the analysis conducted to achieve a balance between low cost and acceptable rotordynamic behavior, to ensure that the ALS FTP will operate reliably without subsynchronous instabilities or excessive bearing loads.

Space shuttle main engine: Interactive design challenges

NASA Technical Reports Server (NTRS)

Mccarty, J. P.; Wood, B. K.

1985-01-01

The operating requirements established by NASA for the SSME were considerably more demanding than those for earlier rocket engines used in the military launch vehicles or Apollo program. The SSME, in order to achieve the high performance, low weight, long life, reusable objectives, embodied technical demands far in excess of its predecessor rocket engines. The requirements dictated the use of high combustion pressure and the staged combustion cycle which maximizes performance through total use of all propellants in the main combustion process. This approach presented a myriad of technical challenges for maximization of performance within attainable state of the art capabilities for operating pressures, operating temperatures and rotating machinery efficiencies. Controlling uniformity of the high pressure turbomachinery turbine temperature environment was a key challenge for thrust level and life capability demanding innovative engineering. New approaches in the design of the components were necessary to accommodate the multiple use, minimum maintenance objectives. Included were the use of line replaceable units to facilitate field maintenance automatic checkout and internal inspection capabilities.

Duct flow nonuniformities for Space Shuttle Main Engine (SSME)

NASA Technical Reports Server (NTRS)

1987-01-01

A three-duct Space Shuttle Main Engine (SSME) Hot Gas Manifold geometry code was developed for use. The methodology of the program is described, recommendations on its implementation made, and an input guide, input deck listing, and a source code listing provided. The code listing is strewn with an abundance of comments to assist the user in following its development and logic. A working source deck will be provided. A thorough analysis was made of the proper boundary conditions and chemistry kinetics necessary for an accurate computational analysis of the flow environment in the SSME fuel side preburner chamber during the initial startup transient. Pertinent results were presented to facilitate incorporation of these findings into an appropriate CFD code. The computation must be a turbulent computation, since the flow field turbulent mixing will have a profound effect on the chemistry. Because of the additional equations demanded by the chemistry model it is recommended that for expediency a simple algebraic mixing length model be adopted. Performing this computation for all or selected time intervals of the startup time will require an abundance of computer CPU time regardless of the specific CFD code selected.

KSC-04pd1641

NASA Image and Video Library

2004-08-03

KENNEDY SPACE CENTER, FLA. - In the Space Shuttle Main Engine (SSME) Processing Facility, Boeing-Rocketdyne technicians prepare to move SSME 2058, the first SSME fully assembled at KSC. Move conductor Bob Brackett (on ladder) supervises the placement of a sling around the engine with the assistance of crane operator Joe Ferrante (center) and a technician. The engine will be lifted from its vertical work stand into a horizontal position in preparation for shipment to NASA’s Stennis Space Center in Mississippi to undergo a hot fire acceptance test. It is the first of five engines to be fully assembled on site to reach the desired number of 15 engines ready for launch at any given time in the Space Shuttle program. A Space Shuttle has three reusable main engines. Each is 14 feet long, weighs about 7,800 pounds, is seven-and-a-half feet in diameter at the end of its nozzle, and generates almost 400,000 pounds of thrust. Historically, SSMEs were assembled in Canoga Park, Calif., with post-flight inspections performed at KSC. Both functions were consolidated in February 2002. The Rocketdyne Propulsion and Power division of The Boeing Co. manufactures the engines for NASA.

KSC-04PD-2511

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, a technician appears to ride the Space Shuttle Main Engine (SSME) as he maneuvers the SSME on the Hyster lift into position for installation on Discovery, the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

KSC-04PD-2513

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, a technician appears to ride the Space Shuttle Main Engine (SSME) as he maneuvers the SSME on the Hyster lift into position for installation on Discovery, the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

Application of Weibull analysis to SSME hardware

NASA Technical Reports Server (NTRS)

Gray, L. A. B.

1986-01-01

Generally, it has been documented that the wearing of engine parts forms a failure distribution which can be approximated by a function developed by Weibull. The purpose here is to examine to what extent the Weibull distribution approximates failure data for designated engine parts of the Space Shuttle Main Engine (SSME). The current testing certification requirements will be examined in order to establish confidence levels. An examination of the failure history of SSME parts/assemblies (turbine blades, main combustion chamber, or high pressure fuel pump first stage impellers) which are limited in usage by time or starts will be done by using updated Weibull techniques. Efforts will be made by the investigator to predict failure trends by using Weibull techniques for SSME parts (turbine temperature sensors, chamber pressure transducers, actuators, and controllers) which are not severely limited by time or starts.

STS-51 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1993-01-01

The STS-51 Space Shuttle Program Mission Report summarizes the payloads as well as the orbiter, external tank (ET), solid rocket booster (SRB), redesigned solid rocket motor (RSRM), and the space shuttle main engine (SSME) systems performance during the fifty-seventh flight of the space shuttle program and seventeenth flight of the orbiter vehicle Discovery (OV-103). In addition to the orbiter, the flight vehicle consisted of an ET designated as ET-59; three SSME's, which were designated as serial numbers 2031, 2034, and 2029 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-060. The lightweight RSRM's that were installed in each SRB were designated as 360W033A for the left SRB and 360L033B for the right SRB.

Engine systems analysis results of the Space Shuttle Main Engine redesigned powerhead initial engine level testing

NASA Technical Reports Server (NTRS)

Sander, Erik J.; Gosdin, Dennis R.

1992-01-01

Engineers regularly analyze SSME ground test and flight data with respect to engine systems performance. Recently, a redesigned SSME powerhead was introduced to engine-level testing in part to increase engine operational margins through optimization of the engine internal environment. This paper presents an overview of the MSFC personnel engine systems analysis results and conclusions reached from initial engine level testing of the redesigned powerhead, and further redesigns incorporated to eliminate accelerated main injector baffle and main combustion chamber hot gas wall degradation. The conclusions are drawn from instrumented engine ground test data and hardware integrity analysis reports and address initial engine test results with respect to the apparent design change effects on engine system and component operation.

Assessment of crack growth in a space shuttle main engine first-stage, high-pressure fuel turbopump blade

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali

1993-01-01

A two-dimensional finite element fracture mechanics analysis of a space shuttle main engine (SSME) turbine blade firtree was performed using the MARC finite element code. The analysis was conducted under combined effects of thermal and mechanical loads at steady-state conditions. Data from a typical engine stand cycle of the SSME were used to run a heat transfer analysis and, subsequently, a thermal structural fracture mechanics analysis. Temperature and stress contours for the firtree under these operating conditions were generated. High stresses were found at the firtree lobes where crack initiation was triggered. A life assessment of the firtree was done by assuming an initial and a final crack size.

SSME Key Operations Demonstration

NASA Technical Reports Server (NTRS)

Anderson, Brian; Bradley, Michael; Ives, Janet

1997-01-01

A Space Shuttle Main Engine (SSME) test program was conducted between August 1995 and May 1996 using the Technology Test Bed (TTB) Engine. SSTO vehicle studies have indicated that increases in the propulsion system operating range can save significant weight and cost at the vehicle level. This test program demonstrated the ability of the SSME to accommodate a wide variation in safe operating ranges and therefore its applicability to the SSTO mission. A total of eight tests were completed with four at Marshall Space Flight Center's Advanced Engine Test Facility and four at the Stennis Space Center (SSC) A-2 attitude test stand. Key demonstration objectives were: 1) Mainstage operation at 5.4 to 6.9 mixture ratio; 2) Nominal engine start with significantly reduced engine inlet pressures of 50 psia LOX and 38 psia fuel; and 3) Low power level operation at 17%, 22%, 27%, 40%, 45%, and 50% of Rated Power Level. Use of the highly instrumented TTB engine for this test series has afforded the opportunity to study in great detail engine system operation not possible with a standard SSME and has significantly contributed to a greater understanding of the capabilities of the SSME and liquid rocket engines in general.

Analysis of SSME HPOTP rotordynamics subsynchronous whirl

NASA Technical Reports Server (NTRS)

1984-01-01

The causes and remedies of vibration and subsynchronous whirl problems encountered in the Shuttle Main Engine SSME turbomachinery are analyzed. Because the nonlinear and linearized models of the turbopumps play such an important role in the analysis process, the main emphasis is concentrated on the verification and improvement of these tools. It has been the goal of our work to validate the equations of motion used in the models are validated, including the assumptions upon which they are based. Verification of th SSME rotordynamics simulation and the developed enhancements, are emphasized.

Develop advanced nonlinear signal analysis topographical mapping system

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1993-01-01

This study will provide timely assessment of SSME component operational status, identify probable causes of malfunction, and indicate feasible engineering solutions. The final result of this program will yield an advanced nonlinear signal analysis topographical mapping system (ATMS) of nonlinear and nonstationary spectral analysis software package integrated with the Compressed SSME TOPO Data Base (CSTDB) on the same platform. This system will allow NASA engineers to retrieve any unique defect signatures and trends associated with different failure modes and anomalous phenomena over the entire SSME test history across turbopump families.

General view looking down the approximate centerline of the expansion ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view looking down the approximate centerline of the expansion nozzle of a Space Shuttle Main Engine (SSME) mounted on a SSME Engine Handler in the SSME Processing Facility at Kennedy Space Center. This view shows the 1080 cooling tubes used to regeneratively cool the Nozzle and Combustion Chamber by circulating relatively low temperature fuel through the tubes and manifolds before being ignited in the Main Combustion Chamber. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Radiation effect on rocket engine performance

NASA Technical Reports Server (NTRS)

Chiu, Huei-Huang

1988-01-01

The effects of radiation on the performance of modern rocket propulsion systems operating at high pressure and temperature were recognized as a key issue in the design and operation of various liquid rocket engines of the current and future generations. Critical problem areas of radiation coupled with combustion of bipropellants are assessed and accounted for in the formulation of a universal scaling law incorporated with a radiation-enhanced vaporization combustion model. Numerical algorithms are developed and the pertaining data of the Variable Thrust Engine (VTE) and Space Shuttle Main Engine (SSME) are used to conduct parametric sensitivity studies to predict the principal intercoupling effects of radiation. The analysis reveals that low enthalpy engines, such as the VTE, are vulnerable to a substantial performance set back by the radiative loss, whereas the performance of high enthalpy engines such as the SSME, are hardly affected over a broad range of engine operation. Additionally, combustion enhancement by the radiative heating of the propellant has a significant impact in those propellants with high absorptivity. Finally, the areas of research related with radiation phenomena in bipropellant engines are identified.

Faces of SSME

NASA Technical Reports Server (NTRS)

2009-01-01

Several employees who contributed to the Space Shuttle Main Engine (SSME) program describe their most memorable experiences relating to the launching of the Space Shuttle. Some describe the emotional aspects they experienced while watching and filming the launch from Kennedy Space Center.

Duct flow nonuniformities study for space shuttle main engine

NASA Technical Reports Server (NTRS)

Thoenes, J.

1985-01-01

To improve the Space Shuttle Main Engine (SSME) design and for future use in the development of generation rocket engines, a combined experimental/analytical study was undertaken with the goals of first, establishing an experimental data base for the flow conditions in the SSME high pressure fuel turbopump (HPFTP) hot gas manifold (HGM) and, second, setting up a computer model of the SSME HGM flow field. Using the test data to verify the computer model it should be possible in the future to computationally scan contemplated advanced design configurations and limit costly testing to the most promising design. The effort of establishing and using the computer model is detailed. The comparison of computational results and experimental data observed clearly demonstrate that computational fluid mechanics (CFD) techniques can be used successfully to predict the gross features of three dimensional fluid flow through configurations as intricate as the SSME turbopump hot gas manifold.

Thin-film sensors for space propulsion technology: Fabrication and preparation for testing

NASA Technical Reports Server (NTRS)

Kim, Walter S.; Hepp, Aloysius F.

1989-01-01

The goal of this work is to develop and test thin-film thermocouples for Space Shuttle Main Engine (SSME) components. Thin-film thermocouples have been developed for aircraft gas turbine engines and are in use for temperature measurement on turbine blades up to 1800 F. Established aircraft engine gas turbine technology is currently being adapted to turbine engine blade materials and the environment encountered in the SSME, especially severe thermal shock from cryogenic fuel to combustion temperatures. Initial results using coupons of MAR M-246 (+Hf) and PWA 1480 have been followed by fabrication of thin-film thermocouples on SSME turbine blades. Current efforts are focused on preparing for testing in the Turbine Blade Tester at the NASA Marshall Space Flight Center (MSFC). Future work will include testing of thin-film thermocouples on SSME blades of single crystal PWA 1480 at MSFC.

Remtech SSME nozzle design TPS

NASA Technical Reports Server (NTRS)

Bancroft, Steven A.; Engel, Carl D.; Pond, John E.

1990-01-01

Thermal damage to the Space Shuttle Main Engine (SSME) aft manifold Thermal Protection System (TPS) has been observed for flights STS-8 through STS-13. This damaged area is located on the ME2 and ME3 and extends over a region of approximately one square foot. Total failure or burn-through of the TPS could lead to severe thermal damage of the SSME manifold and loss of an engine nozzle necessitating nozzle replacement causing significant schedule delays and cost increases. Thermal damage to the manifold can be defined as a situation where the manifold temperature becomes greater than 1300 F; thereby causing loss of heat treatment in the nozzle. Results of Orbiter/nozzle wind tunnel tests and Hot Gas Facility tests of the TPS are presented. Aerothermal and thermal analysis models for the SSME aft manifold are discussed along with the flight predictions, design trajectory and design environment. Finally, the TPS design concept and TPS thermal response are addressed.

RS-25 for the NASA Cargo Launch Vehicle: The Evolution of SSME for Space Exploration

NASA Technical Reports Server (NTRS)

Kynard, Michael H.; McArthur, J. Craig; Ise, Dayna S.

2006-01-01

A key element of the National Vision for Space Exploration is the development of a heavy-lift Cargo Launch Vehicle (CaLV). Missions to the Moon, Mars, and beyond are only possible with the logistical capacity of putting large payloads in low-earth orbit. However, beyond simple logistics, there exists the need for this capability to be as cost effective as possible to ensure mission sustainability. An element of the CaLV project is, therefore, the development of the RS-25, which represents the evolution of the proven Space Shuttle Main Engine (SSME) into a high-performance, cost-effective expendable rocket engine. The development of the RS-25 will be built upon the foundation of over one million seconds of accumulated hot-fire time on the SSME. Yet in order to transform the reusable SSME into the more cost-effective, expendable RS-25 changes will have to be made. Thus the project will inevitably strive to maintain a balance between demonstrated heritage products and processes and the utilization of newer technology developments. Towards that end, the Core Stage Engine Office has been established at the NASA Marshall Space Flight Center to initiate the design and development of the RS-25 engine. This paper is being written very early in the formulation phase of the RS-25 project. Therefore the focus of this paper will be to present the scope, challenges, and opportunities for the RS-25 project. Early schedules and development decisions and plans will be explained. For not only must the RS-25 project achieve cost effectiveness through the development of new, evolved components such as a channel-wall nozzle, a new HIP-bonded main combustion chamber, and several others, it must simultaneously develop the means whereby this engine can be manufactured on a scale never envisioned for the SSME. Thus, while the overall project will span the next eight to ten years, there is little doubt that even this schedule is aggressive with a great deal of work to accomplish.

STS-44 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1992-01-01

The STS-44 Space Shuttle Program Mission Report is a summary of the vehicle subsystem operations during the forty-fourth flight of the Space Shuttle Program and the tenth flight of the Orbiter vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-53 (LWT-46); three Space Shuttle main engines (SSME's) (serial numbers 2015, 2030, and 2029 in positions 1, 2, and 3, respectively); and two Solid Rocket Boosters (SRB's) designated as BI-047. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each one of the SRB's were designated as 360L019A for the left SRB and 360W019B for the right SRB. The primary objective of the STS-44 mission was to successfully deploy the Department of Defense (DOD) Defense Support Program (DSP) satellite/inertial upper stage (IUS) into a 195 nmi. earth orbit at an inclination of 28.45 deg. Secondary objectives of this flight were to perform all operations necessary to support the requirements of the following: Terra Scout, Military Man in Space (M88-1), Air Force Maui Optical System Calibration Test (AMOS), Cosmic Radiation Effects and Activation Monitor (CREAM), Shuttle Activation Monitor (SAM), Radiation Monitoring Equipment-3 (RME-3), Visual Function Tester-1 (VFT-1), and the Interim Operational Contamination Monitor (IOCM) secondary payloads/experiments.

STS-56 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1993-01-01

The STS-56 Space Shuttle Program Mission Report provides a summary of the Payloads, as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the fifty-fourth flight of the Space Shuttle Program and sixteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Orbiter, the flight vehicle consisted of an ET (ET-54); three SSME's, which were designated as serial numbers 2024, 2033, and 2018 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-058. The lightweight RSRM's that were installed in each SRB were designated as 360L031A for the left SRB and 360L031B for the right SRB.

SSME thrust chamber simulation using Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Przekwas, A. J.; Singhal, A. K.; Tam, L. T.

1984-01-01

The capability of the PHOENICS fluid dynamics code in predicting two-dimensional, compressible, and reacting flow in the combustion chamber and nozzle of the space shuttle main engine (SSME) was evaluated. A non-orthogonal body fitted coordinate system was used to represent the nozzle geometry. The Navier-Stokes equations were solved for the entire nozzle with a turbulence model. The wall boundary conditions were calculated based on the wall functions which account for pressure gradients. Results of the demonstration test case reveal all expected features of the transonic nozzle flows. Of particular interest are the locations of normal and barrel shocks, and regions of highest temperature gradients. Calculated performance (global) parameters such as thrust chamber flow rate, thrust, and specific impulse are also in good agreement with available data.

Rocket Science: The Shuttle's Main Engines, though Old, Are not Forgotten in the New Exploration Initiative

NASA Technical Reports Server (NTRS)

Covault, Craig

2005-01-01

The Space Shuttle Main Engine (SSME), developed 30 years ago, remains a strong candidate for use in the new Exploration Initiative as part of a shuttle-derived heavy-lift expendable booster. This is because the Boeing-Rocket- dyne man-rated SSME remains the most highly efficient liquid rocket engine ever developed. There are only enough parts for 12-15 existing SSMEs, however, so one NASA option is to reinitiate SSME production to use it as a throw-away, as opposed to a reusable, powerplant for NASA s new heavy-lift booster.

Digital filtering of plume emission spectra

NASA Technical Reports Server (NTRS)

Madzsar, George C.

1990-01-01

Fourier transformation and digital filtering techniques were used to separate the superpositioned spectral phenomena observed in the exhaust plumes of liquid propellant rocket engines. Space shuttle main engine (SSME) spectral data were used to show that extraction of spectral lines in the spatial frequency domain does not introduce error, and extraction of the background continuum introduces only minimal error. Error introduced during band extraction could not be quantified due to poor spectrometer resolution. Based on the atomic and molecular species found in the SSME plume, it was determined that spectrometer resolution must be 0.03 nm for SSME plume spectral monitoring.

Spares Management : Optimizing Hardware Usage for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Gulbrandsen, K. A.

1999-01-01

The complexity of the Space Shuttle Main Engine (SSME), combined with mounting requirements to reduce operations costs have increased demands for accurate tracking, maintenance, and projections of SSME assets. The SSME Logistics Team is developing an integrated asset management process. This PC-based tool provides a user-friendly asset database for daily decision making, plus a variable-input hardware usage simulation with complex logic yielding output that addresses essential asset management issues. Cycle times on critical tasks are significantly reduced. Associated costs have decreased as asset data quality and decision-making capability has increased.

Analysis of physical-chemical processes governing SSME internal fluid flows

NASA Technical Reports Server (NTRS)

Singhal, A. K.; Owens, S. F.; Mukerjee, T.; Keeton, L. W.; Prakash, C.; Przekwas, A. J.

1984-01-01

The efforts to adapt CHAM's computational fluid dynamics code, PHOENICS, to the analysis of flow within the high pressure fuel turbopump (HPFTP) aft-platform seal cavity of the SSME are summarized. In particular, the special purpose PHOENICS satellite and ground station specifically formulated for this application are listed and described, and the preliminary results of the first part two-dimensional analyses are presented and discussed. Planned three-dimensional analyses are also briefly outlined. To further understand the mixing and combustion processes in the SSME fuelside preburners, a single oxygen-hydrogen jet element was investigated.

Report of the SSME assessment team

NASA Technical Reports Server (NTRS)

1993-01-01

In response to a request from the House of Representatives Committee on Science, Space, and Technology in its Report No. 102-500 of April 22, 1992, the Aerospace Safety Advisory Panel (ASAP) created an ad hoc task force to conduct a thorough assessment of the Space Shuttle Main Engine (SSME). The membership was drawn mostly from organizations other than ASAP, and this report represents the views of that task force. Its task was to assess the risk that the SSME poses to the safe operation of the Space Shuttle, to identify and evaluate improvements to the engine that would reduce the risk, and to recommend a set of priorities for the implementation of these improvements. The SSME Assessment Team, as it opted to call itself, convened in mid-1992 and, subsequently, met with and gathered information from all the principal organizations involved in the SSME program. These included the Rocketdyne Division of Rockwell International, the Marshall Space Flight Center of NASA, and the Pratt & Whitney Division of United Technologies Corporation. The information in this report reflects the program status as of October 1992. From the information received, the Team formed its conclusions and recommendations. Changes in the program status have, of course, occurred since that time; however, they did not affect the Team's conclusions and recommendations.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 3B: High pressure fuel turbo-pump preburner pump bearing assembly analysis

NASA Technical Reports Server (NTRS)

Power, Gloria B.; Violett, Rebeca S.

1989-01-01

The analysis performed on the High Pressure Oxidizer Turbopump (HPOTP) preburner pump bearing assembly located on the Space Shuttle Main Engine (SSME) is summarized. An ANSYS finite element model for the inlet assembly was built and executed. Thermal and static analyses were performed.

Turnaround Time Modeling for Conceptual Rocket Engines

NASA Technical Reports Server (NTRS)

Nix, Michael; Staton, Eric J.

2004-01-01

Recent years have brought about a paradigm shift within NASA and the Space Launch Community regarding the performance of conceptual design. Reliability, maintainability, supportability, and operability are no longer effects of design; they have moved to the forefront and are affecting design. A primary focus of this shift has been a planned decrease in vehicle turnaround time. Potentials for instituting this decrease include attacking the issues of removing, refurbishing, and replacing the engines after each flight. less, it is important to understand the operational affects of an engine on turnaround time, ground support personnel and equipment. One tool for visualizing this relationship involves the creation of a Discrete Event Simulation (DES). A DES model can be used to run a series of trade studies to determine if the engine is meeting its requirements, and, if not, what can be altered to bring it into compliance. Using DES, it is possible to look at the ways in which labor requirements, parallel maintenance versus serial maintenance, and maintenance scheduling affect the overall turnaround time. A detailed DES model of the Space Shuttle Main Engines (SSME) has been developed. Trades may be performed using the SSME Processing Model to see where maintenance bottlenecks occur, what the benefits (if any) are of increasing the numbers of personnel, or the number and location of facilities, in addition to trades previously mentioned, all with the goal of optimizing the operational turnaround time and minimizing operational cost. The SSME Processing Model was developed in such a way that it can easily be used as a foundation for developing DES models of other operational or developmental reusable engines. Performing a DES on a developmental engine during the conceptual phase makes it easier to affect the design and make changes to bring about a decrease in turnaround time and costs.

Combination of magnetic dispersive micro solid-phase extraction and supramolecular solvent-based microextraction followed by high-performance liquid chromatography for determination of trace amounts of cholesterol-lowering drugs in complicated matrices.

PubMed

Arghavani-Beydokhti, Somayeh; Rajabi, Maryam; Asghari, Alireza

2017-07-01

A novel, efficient, rapid, simple, sensitive, selective, and environmentally friendly method termed magnetic dispersive micro solid-phase extraction combined with supramolecular solvent-based microextraction (Mdμ-SPE-SSME) followed by high-performance liquid chromatography (HPLC) with UV detection is introduced for the simultaneous microextraction of cholesterol-lowering drugs in complicated matrices. In the first microextraction procedure, using layered double hydroxide (LDH)-coated Fe 3 O 4 magnetic nanoparticles, an efficient sample cleanup is simply and rapidly provided without the need for time-consuming centrifugation and elution steps. In the first step, desorption of the target analytes is easily performed through dissolution of the LDH-coated magnetic nanoparticles containing the target analytes in an acidic solution. In the next step, an emulsification microextraction method based on a supramolecular solvent is used for excellent preconcentration, ultimately resulting in an appropriate determination of the target analytes in real samples. Under the optimal experimental conditions, the Mdμ-SPE-SSME-HPLC-UV detection procedure provides good linearity in the ranges of 1.0-1500 ng mL -1 , 1.5-2000 ng mL -1 , and 2.0-2000 ng mL -1 with coefficients of determination of 0.995 or less, low limits of detection (0.3, 0.5, and 0.5 ng mL -1 ), and good extraction repeatabilities (relative standard deviations below 7.8%, n = 5) in deionized water for rosuvastatin, atorvastatin, and gemfibrozil, respectively. Finally, the proposed method is successfully applied for the determination of the target analytes in complicated matrices. Graphical Abstract Mdμ-SPE-SSME procedure.

Integrated system for investigating sub-surface features of a rock formation

DOEpatents

Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre -Yves; Larmat, Carene S.

2015-08-18

A system for investigating non-linear properties of a rock formation around a borehole is provided. The system includes a first sub-system configured to perform data acquisition, control and recording of data; a second subsystem in communication with the first sub-system and configured to perform non-linearity and velocity preliminary imaging; a third subsystem in communication with the first subsystem and configured to emit controlled acoustic broadcasts and receive acoustic energy; a fourth subsystem in communication with the first subsystem and the third subsystem and configured to generate a source signal directed towards the rock formation; and a fifth subsystem in communication with the third subsystem and the fourth subsystem and configured to perform detection of signals representative of the non-linear properties of the rock formation.

Hotfire testing of a SSME HPOTP with an annular hydrostatic bearing

NASA Technical Reports Server (NTRS)

Nolan, Steven A.; Hibbs, Robert I.; Genge, Gary G.

1993-01-01

A new fluid film bearing package has been tested in the SSME High Pressure Oxygen Turbopump (HPOTP). This fluid film element functions as both the pump end bearing and the preburner pump rear wear ring seal. Most important, it replaces a duplex ball bearing package which has been the primary life limiting component in the turbopump. The design and predicted performance of the turbopump are reviewed. Results are presented for measured pump and bearing performance. The most significant results were obtained from proximity probes located in the bearing bore which revealed large subsynchronous precession at 10 percent of shaft speed during engine start which subsided prior to mainstage power levels and reappeared during engine shutdown at equivalent power levels below 65 percent of nominal. This phenomenon has been attributed to rotating stall in the diffuser. The proximity probes also revealed the location of the bearing in the bore for different operating speeds. Pump vibration characteristics were improved as compared to pumps tested with ball bearings. After seven starts and more than 700 seconds of testing, the pump showed no signs of performance degradation.

Applications Technology Satellite ATS-6 in orbit checkout report

NASA Technical Reports Server (NTRS)

Moore, W.; Prensky, W. (Editor)

1974-01-01

The activities of the ATS-6 spacecraft for the checkout period of approximately four weeks beginning May 30, 1974 are described, along with the results of a performance evaluation of its subsystems and components. The following specific items are discussed: (1) subsystem requirements/specifications and in-orbit performance summary; (2) flight chronology; (3) spacecraft description; (4) structural/deployment subsystems; (5) electrical power subsystem; (6) thermal control subsystem; (7) telemetry and command subsystems; (8) attitude control subsystem; (9) spacecraft propulsion subsystem; (10) communication subsystem; and (12) experiment subsystem.

SSME lifetime prediction and verification, integrating environments, structures, materials: The challenge

NASA Technical Reports Server (NTRS)

Ryan, R. S.; Salter, L. D.; Young, G. M., III; Munafo, P. M.

1985-01-01

The planned missions for the space shuttle dictated a unique and technology-extending rocket engine. The high specific impulse requirements in conjunction with a 55-mission lifetime, plus volume and weight constraints, produced unique structural design, manufacturing, and verification requirements. Operations from Earth to orbit produce severe dynamic environments, which couple with the extreme pressure and thermal environments associated with the high performance, creating large low cycle loads and high alternating stresses above endurance limit which result in high sensitivity to alternating stresses. Combining all of these effects resulted in the requirements for exotic materials, which are more susceptible to manufacturing problems, and the use of an all-welded structure. The challenge of integrating environments, dynamics, structures, and materials into a verified SSME structure is discussed. The verification program and developmental flight results are included. The first six shuttle flights had engine performance as predicted with no failures. The engine system has met the basic design challenges.

STS-55 pad abort: Engine 2011 oxidizer preburner augmented spark igniter check valve leak

NASA Technical Reports Server (NTRS)

1993-01-01

The STS-55 initial launch attempt of Columbia (OV102) was terminated on KSC launch pad A March 22, 1993 at 9:51 AM E.S.T. due to violation of an ME-3 (Engine 2011) Launch Commit Criteria (LCC) limit exceedance. The event description and timeline are summarized. Propellant loading was initiated on 22 March, 1993 at 1:15 AM EST. All SSME chill parameters and launch commit criteria (LCC) were nominal. At engine start plus 1.44 seconds, a Failure Identification (FID) was posted against Engine 2011 for exceeding the 50 psia Oxidizer Preburner (OPB) purge pressure redline. The engine was shut down at 1.50 seconds followed by Engines 2034 and 2030. All shut down sequences were nominal and the mission was safely aborted. The OPB purge pressure redline violation and the abort profile/overlay for all three engines are depicted. SSME Avionics hardware and software performed nominally during the incident. A review of vehicle data table (VDT) data and controller software logic revealed no failure indications other than the single FID 013-414, OPB purge pressure redline exceeded. Software logic was executed according to requirements and there was no anomalous controller software operation. Immediately following the abort, a Rocketdyne/NASA failure investigation team was assembled. The team successfully isolated the failure cause to the oxidizer preburner augmented spark igniter purge check valve not being fully closed due to contamination. The source of the contaminant was traced to a cut segment from a rubber O-ring which was used in a fine clean tool during valve production prior to 1992. The valve was apparently contaminated during its fabrication in 1985. The valve had performed acceptably on four previous flights of the engine, and SSME flight history shows 780 combined check valve flights without failure. The failure of an Engine 3 (SSME No. 2011) check valve to close was sensed by onboard engine instruments even though all other engine operations were normal. This resulted in an engine shutdown and safe sequential shutdown of all three engines prior to ignition of the solid boosters.

Application of fault factor method to fault detection and diagnosis for space shuttle main engine

NASA Astrophysics Data System (ADS)

Cha, Jihyoung; Ha, Chulsu; Ko, Sangho; Koo, Jaye

2016-09-01

This paper deals with an application of the multiple linear regression algorithm to fault detection and diagnosis for the space shuttle main engine (SSME) during a steady state. In order to develop the algorithm, the energy balance equations, which balances the relation among pressure, mass flow rate and power at various locations within the SSME, are obtained. Then using the measurement data of some important parameters of the engine, fault factors which reflects the deviation of each equation from the normal state are estimated. The probable location of each fault and the levels of severity can be obtained from the estimated fault factors. This process is numerically demonstrated for the SSME at 104% Rated Propulsion Level (RPL) by using the simulated measurement data from the mathematical models of the engine. The result of the current study is particularly important considering that the recently developed reusable Liquid Rocket Engines (LREs) have staged-combustion cycles similarly to the SSME.

Closeup view of the bottom area of Space Shuttle Main ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the bottom area of Space Shuttle Main Engine (SSME) 2052 engine assembly mounted in a SSME Engine Handler in the Horizontal Processing area of the SSME Processing Facility at Kennedy Space Center. The most prominent features in this view are the Low-Pressure Oxidizer Discharge Duct toward the bottom of the assembly, the SSME Engine Controller and the Main Fuel Valve Hydraulic Actuator are in the approximate center of the assembly in this view, the Low-Pressure Fuel Turbopump (LPFTP), the LPFTP Discharge Duct are to the left on the assembly in this view and the High-Pressure Fuel Turbopump is located toward the top of the engine assembly in this view. The ring of tabs in the right side of the image, at the approximate location of the Nozzle and the Coolant Outlet Manifold interface is the Heat Shield Support Ring. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Evolution of magnetic disk subsystems

NASA Astrophysics Data System (ADS)

Kaneko, Satoru

1994-06-01

The higher recording density of magnetic disk realized today has brought larger storage capacity per unit and smaller form factors. If the required access performance per MB is constant, the performance of large subsystems has to be several times better. This article describes mainly the technology for improving the performance of the magnetic disk subsystems and the prospects of their future evolution. Also considered are 'crosscall pathing' which makes the data transfer channel more effective, 'disk cache' which improves performance coupling with solid state memory technology, and 'RAID' which improves the availability and integrity of disk subsystems by organizing multiple disk drives in a subsystem. As a result, it is concluded that since the performance of the subsystem is dominated by that of the disk cache, maximation of the performance of the disk cache subsystems is very important.

SSME structural computer program development. Volume 3: BOPACE demonstration analysis of the SSME thrust chamber liner

NASA Technical Reports Server (NTRS)

Spring, A. H.

1973-01-01

The application of a structural computer program for analysis of a thrust chamber liner is discussed. Two objectives were accomplished as follows: (1) exercise of the full capabilities of the computer program and (2) definition of thermal and mechanical boundary conditions to reflect the emergency power level operating conditions for the SSME 47OK engine at a station just upstream of the thrust chamber throat. Creep information on the thrust chamber is presented as a reference curve of creep strain versus time for various temperatures. Contour plots of the effective plastic strain, effective stress, and effective creep strain are developed.

Reusable rocket engine intelligent control system framework design, phase 2

NASA Technical Reports Server (NTRS)

Nemeth, ED; Anderson, Ron; Ols, Joe; Olsasky, Mark

1991-01-01

Elements of an advanced functional framework for reusable rocket engine propulsion system control are presented for the Space Shuttle Main Engine (SSME) demonstration case. Functional elements of the baseline functional framework are defined in detail. The SSME failure modes are evaluated and specific failure modes identified for inclusion in the advanced functional framework diagnostic system. Active control of the SSME start transient is investigated, leading to the identification of a promising approach to mitigating start transient excursions. Key elements of the functional framework are simulated and demonstration cases are provided. Finally, the advanced function framework for control of reusable rocket engines is presented.

Evolutionary Development of the Simulation by Logical Modeling System (SIBYL)

NASA Technical Reports Server (NTRS)

Wu, Helen

1995-01-01

Through the evolutionary development of the Simulation by Logical Modeling System (SIBYL) we have re-engineered the expensive and complex IBM mainframe based Long-term Hardware Projection Model (LHPM) to a robust cost-effective computer based mode that is easy to use. We achieved significant cost reductions and improved productivity in preparing long-term forecasts of Space Shuttle Main Engine (SSME) hardware. The LHPM for the SSME is a stochastic simulation model that projects the hardware requirements over 10 years. SIBYL is now the primary modeling tool for developing SSME logistics proposals and Program Operating Plan (POP) for NASA and divisional marketing studies.

An Assessment Methodology to Evaluate In-Flight Engine Health Management Effectiveness

NASA Astrophysics Data System (ADS)

Maggio, Gaspare; Belyeu, Rebecca; Pelaccio, Dennis G.

2002-01-01

flight effectiveness of candidate engine health management system concepts. A next generation engine health management system will be required to be both reliable and robust in terms of anomaly detection capability. The system must be able to operate successfully in the hostile, high-stress engine system environment. This implies that its system components, such as the instrumentation, process and control, and vehicle interface and support subsystems, must be highly reliable. Additionally, the system must be able to address a vast range of possible engine operation anomalies through a host of different types of measurements supported by a fast algorithm/architecture processing capability that can identify "true" (real) engine operation anomalies. False anomaly condition reports for such a system must be essentially eliminated. The accuracy of identifying only real anomaly conditions has been an issue with the Space Shuttle Main Engine (SSME) in the past. Much improvement in many of the technologies to address these areas is required. The objectives of this study were to identify and demonstrate a consistent assessment methodology that can evaluate the capability of next generation engine health management system concepts to respond in a correct, timely manner to alleviate an operational engine anomaly condition during flight. Science Applications International Corporation (SAIC), with support from NASA Marshall Space Flight Center, identified a probabilistic modeling approach to assess engine health management system concept effectiveness using a deterministic anomaly-time event assessment modeling approach that can be applied in the engine preliminary design stage of development to assess engine health management system concept effectiveness. Much discussion in this paper focuses on the formulation and application approach in performing this assessment. This includes detailed discussion of key modeling assumptions, the overall assessment methodology approach identified, and the identification of key supporting engine health management system concept design/operation and fault mode information required to utilize this methodology. At the paper's conclusion, discussion focuses on a demonstration benchmark study that applied this methodology to the current SSME health management system. A summary of study results and lessons learned are provided. Recommendations for future work in this area are also identified at the conclusion of the paper. * Please direct all correspondence/communication pertaining to this paper to Dennis G. Pelaccio, Science

SSME structural dynamic model development

NASA Technical Reports Server (NTRS)

Foley, M. J.; Tilley, D. M.; Welch, C. T.

1983-01-01

A mathematical model of the Space Shuttle Main Engine (SSME) as a complete assembly, with detailed emphasis on LOX and High Fuel Turbopumps is developed. The advantages of both complete engine dynamics, and high fidelity modeling are incorporated. Development of this model, some results, and projected applications are discussed.

STS-45 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W.

1992-01-01

The STS-45 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-sixth flight of the Space Shuttle Program and the eleventh flight of the Orbiter Vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-44 (LWT-37); three Space Shuttle main engines (SSME's), which were serial numbers 2024, 2012, and 2028 in positions 1, 2, and 3, respectively; and two Solid Rocket Boosters (SRB's) designated as BI-049. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each of the SRB's were designated as 360L021A for the left SRM and 360W021B for the right SRM. The primary objective of this mission was to successfully perform the planned operations of the Atmospheric Laboratory for Applications and Science-1 (ATLAS-1) and the Shuttle Solar Backscatter Ultraviolet Instrument (SSBUV) payloads. The secondary objectives were to successfully perform all operations necessary to support the requirements of the following: the Space Tissue Loss-01 (STL-01) experiment; the Radiation Monitoring Equipment-3 (RME-3) experiment; the Visual Function Tester-2 (VFT-2) experiment; the Cloud Logic to Optimize use of Defense System (CLOUDS-1A) experiment; the Shuttle Amateur Radio Experiment 2 (SAREX-2) Configuration B; the Investigation into Polymer Membranes Processing experiment; and the Get-Away Special (GAS) payload G-229. The Ultraviolet Plume Instrument (UVPI) was a payload of opportunity that required no special maneuvers. In addition to the primary and secondary objectives, the crew was tasked to perform as many as 10 Development Test Objectives (DTO'S) and 14 Detailed Supplementary Objectives (DSO's).

STS-45 Space Shuttle mission report

NASA Astrophysics Data System (ADS)

Fricke, Robert W.

1992-05-01

The STS-45 Space Shuttle Program Mission Report contains a summary of the vehicle subsystem operations during the forty-sixth flight of the Space Shuttle Program and the eleventh flight of the Orbiter Vehicle Atlantis (OV-104). In addition to the Atlantis vehicle, the flight vehicle consisted of the following: an External Tank (ET) designated as ET-44 (LWT-37); three Space Shuttle main engines (SSME's), which were serial numbers 2024, 2012, and 2028 in positions 1, 2, and 3, respectively; and two Solid Rocket Boosters (SRB's) designated as BI-049. The lightweight redesigned Solid Rocket Motors (RSRM's) installed in each of the SRB's were designated as 360L021A for the left SRM and 360W021B for the right SRM. The primary objective of this mission was to successfully perform the planned operations of the Atmospheric Laboratory for Applications and Science-1 (ATLAS-1) and the Shuttle Solar Backscatter Ultraviolet Instrument (SSBUV) payloads. The secondary objectives were to successfully perform all operations necessary to support the requirements of the following: the Space Tissue Loss-01 (STL-01) experiment; the Radiation Monitoring Equipment-3 (RME-3) experiment; the Visual Function Tester-2 (VFT-2) experiment; the Cloud Logic to Optimize use of Defense System (CLOUDS-1A) experiment; the Shuttle Amateur Radio Experiment 2 (SAREX-2) Configuration B; the Investigation into Polymer Membranes Processing experiment; and the Get-Away Special (GAS) payload G-229. The Ultraviolet Plume Instrument (UVPI) was a payload of opportunity that required no special maneuvers. In addition to the primary and secondary objectives, the crew was tasked to perform as many as 10 Development Test Objectives (DTO'S) and 14 Detailed Supplementary Objectives (DSO's).

Controls, health assessment, and conditional monitoring for large, reusable, liquid rocket engines

NASA Technical Reports Server (NTRS)

Cikanek, H. A., III

1986-01-01

Past and future progress in the performance of control systems for large, liquid rocket engines typified such as current state-of-the-art, the Shuttle Main Engine (SSME), is discussed. Details of the first decade of efforts, which culminates in the F-1 and J-2 Saturn engines control systems, are traced, noting problem modes and improvements which were implemented to realize the SSME. Future control system designs, to accommodate the requirements of operation of engines for a heavy lift launch vehicle, an orbital transfer vehicle and the aerospace plane, are summarized. Generic design upgrades needed include an expanded range of fault detection, maintenance as-needed instead of as-scheduled, reduced human involvement in engine operations, and increased control of internal engine states. Current NASA technology development programs aimed at meeting the future control system requirements are described.

Genetic algorithm based input selection for a neural network function approximator with applications to SSME health monitoring

NASA Technical Reports Server (NTRS)

Peck, Charles C.; Dhawan, Atam P.; Meyer, Claudia M.

1991-01-01

A genetic algorithm is used to select the inputs to a neural network function approximator. In the application considered, modeling critical parameters of the space shuttle main engine (SSME), the functional relationship between measured parameters is unknown and complex. Furthermore, the number of possible input parameters is quite large. Many approaches have been used for input selection, but they are either subjective or do not consider the complex multivariate relationships between parameters. Due to the optimization and space searching capabilities of genetic algorithms they were employed to systematize the input selection process. The results suggest that the genetic algorithm can generate parameter lists of high quality without the explicit use of problem domain knowledge. Suggestions for improving the performance of the input selection process are also provided.

Development of an algebraic stress/two-layer model for calculating thrust chamber flow fields

NASA Technical Reports Server (NTRS)

Chen, C. P.; Shang, H. M.; Huang, J.

1993-01-01

Following the consensus of a workshop in Turbulence Modeling for Liquid Rocket Thrust Chambers, the current effort was undertaken to study the effects of second-order closure on the predictions of thermochemical flow fields. To reduce the instability and computational intensity of the full second-order Reynolds Stress Model, an Algebraic Stress Model (ASM) coupled with a two-layer near wall treatment was developed. Various test problems, including the compressible boundary layer with adiabatic and cooled walls, recirculating flows, swirling flows and the entire SSME nozzle flow were studied to assess the performance of the current model. Detailed calculations for the SSME exit wall flow around the nozzle manifold were executed. As to the overall flow predictions, the ASM removes another assumption for appropriate comparison with experimental data, to account for the non-isotropic turbulence effects.

Turbulence modelling of flow fields in thrust chambers

NASA Technical Reports Server (NTRS)

Chen, C. P.; Kim, Y. M.; Shang, H. M.

1993-01-01

Following the consensus of a workshop in Turbulence Modelling for Liquid Rocket Thrust Chambers, the current effort was undertaken to study the effects of second-order closure on the predictions of thermochemical flow fields. To reduce the instability and computational intensity of the full second-order Reynolds Stress Model, an Algebraic Stress Model (ASM) coupled with a two-layer near wall treatment was developed. Various test problems, including the compressible boundary layer with adiabatic and cooled walls, recirculating flows, swirling flows, and the entire SSME nozzle flow were studied to assess the performance of the current model. Detailed calculations for the SSME exit wall flow around the nozzle manifold were executed. As to the overall flow predictions, the ASM removes another assumption for appropriate comparison with experimental data to account for the non-isotropic turbulence effects.

Engine throat/nozzle optics for plume spectroscopy

NASA Technical Reports Server (NTRS)

Bickford, R. L.; Duncan, D. B.

1991-01-01

The Task 2.0 Engine Throat/Nozzle Optics for Plume Spectroscopy, effort was performed under the NASA LeRC Development of Life Prediction Capabilities for Liquid Propellant Rocket Engines program. This Task produced the engineering design of an optical probe to enable spectroscopic measurements within the SSME main chamber. The probe mounts on the SSME nozzle aft manifold and collects light emitted from the throat plane and chamber. Light collected by the probe is transferred to a spectrometer through a fiber optic cable. The design analyses indicate that the probe will function throughout the engine operating cycle and is suitable for both test stand and flight operations. By detecting metallic emissions that are indicative of component degradation or incipient failure, engine shutdown can be initiated before catastrophic failure. This capability will protect valuable test stand hardware and provide enhanced mission safety.

Final Prep on SSME

NASA Image and Video Library

2005-10-25

Alvin Pittman Sr., lead electronics technician with Pratt & Whitney Rocketdyne, and Janine Cuevas, a mechanical technician with PWR, perform final preparations on the space shuttle main engine tested Oct. 25, 2005, at NASA's Stennis Space Center. It was the first main engine test since Hurricane Katrina hit the Gulf Coast on Aug. 29.

Final Prep on SSME

NASA Technical Reports Server (NTRS)

2005-01-01

Alvin Pittman Sr., lead electronics technician with Pratt & Whitney Rocketdyne, and Janine Cuevas, a mechanical technician with PWR, perform final preparations on the space shuttle main engine tested Oct. 25, 2005, at NASA's Stennis Space Center. It was the first main engine test since Hurricane Katrina hit the Gulf Coast on Aug. 29.

A Change of Inertia-Supporting the Thrust Vector Control of the Space Launch System

NASA Technical Reports Server (NTRS)

Dziubanek, Adam J.

2012-01-01

The Space Launch System (SLS) is America's next launch vehicle. To utilize the vehicle more economically, heritage hardware from the Space Transportation System (STS) will be used when possible. The Solid Rocket Booster (SRB) actuators could possibly be used in the core stage of the SLS. The dynamic characteristics of the SRB actuator will need to be tested on an Inertia Load Stand (ILS) that has been converted to Space Shuttle Main Engine (SSME). The inertia on the pendulum of the ILS will need to be changed to match the SSME inertia. In this testing environment an SRB actuator can be tested with the equivalent resistence of an SSME.

General view of the Space Shuttle Main Engine (SSME) assembly ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-Pressure Fuel Turbopump (LPFTP) on the upper left of the engine assembly, the LPFTP Discharge Duct looping around the assembly, the Gimbal Bearing on the top center of the assembly, the Electrical Interface Panel sits just below the Gimbal Bearing and the Low-Pressure Oxidizer Turbopump is mounted on the top right of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

General view of the shop floor looking north in the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the shop floor looking north in the Vertical Processing Area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. SSME number 2061 is in the foreground. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Dynamic balance improvement program

NASA Technical Reports Server (NTRS)

Butner, M. F.

1983-01-01

The reduction of residual unbalance in the space shuttle main engine (SSME) high pressure turbopump rotors was addressed. Elastic rotor response to unbalance and balancing requirements, multiplane and in housing balancing, and balance related rotor design considerations were assessed. Recommendations are made for near term improvement of the SSME balancing and for future study and development efforts.

The Evolution of Utilizing Manual Throttles to Avoid Low LH2 NPSP at the SSME Inlet

NASA Technical Reports Server (NTRS)

Henfling, Rick

2011-01-01

Even before the first flight of the Space Shuttle, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) can have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System could result in a low LH2 NPSP condition. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs, which alleviated the low LH2 NPSP condition. A throttling down of the SSME resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at a lower throttle setting. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of these additional capabilities. Currently the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now would result in a nominal Main Engine Cut Off (MECO) and no loss of mission objectives.

Space Shuttle Main Engine: Advanced Health Monitoring System

NASA Technical Reports Server (NTRS)

Singer, Chirs

1999-01-01

The main gola of the Space Shuttle Main Engine (SSME) Advanced Health Management system is to improve flight safety. To this end the new SSME has robust new components to improve the operating margen and operability. The features of the current SSME health monitoring system, include automated checkouts, closed loop redundant control system, catastropic failure mitigation, fail operational/ fail-safe algorithms, and post flight data and inspection trend analysis. The features of the advanced health monitoring system include: a real time vibration monitor system, a linear engine model, and an optical plume anomaly detection system. Since vibration is a fundamental measure of SSME turbopump health, it stands to reason that monitoring the vibration, will give some idea of the health of the turbopumps. However, how is it possible to avoid shutdown, when it is not necessary. A sensor algorithm has been developed which has been exposed to over 400 test cases in order to evaluate the logic. The optical plume anomaly detection (OPAD) has been developed to be a sensitive monitor of engine wear, erosion, and breakage.

LANDSAT-1 flight evaluation report

NASA Technical Reports Server (NTRS)

1975-01-01

Flight performance analysis for the tenth quarter of operation orbit 11467 to 12745 of LANDSAT 1 are presented. Payload subsystems discussed include: power subsystem; attitude control subsystem; telemetry subsystem; electrical interface subsystem; narrowband tape recorders; wideband telemetry subsystem; return beam vidicon subsystem; multispectral scanner subsystem; and data collection system.

The Evolution of Utilizing Manual Throttles to Avoid Excessively Low LH2 NPSP at the SSME Inlet

NASA Technical Reports Server (NTRS)

Henfling, Rick

2011-01-01

In the late 1970s, years before the Space Shuttle flew its maiden voyage, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) could have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System (MPS) could result in a low LH2 NPSP condition, which at extremely low levels can result in cavitation of SSME turbomachinery. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs (via the Pilot s Speedbrake/Throttle Controller), which alleviated the low LH2 NPSP condition. Manually throttling the SSME to a lower power level resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at the lower throttle setting. Early in the Space Shuttle Program s history, the relevant Flight Rule for the Booster flight controllers in Mission Control did not distinguish between ET and Orbiter MPS failures and the same crew action was taken for both. However, after a review of all Booster operational techniques following the Challenger disaster in the late 1980s, it was determined manually throttling the SSME to a lower power was only effective for Orbiter MPS failures and the Flight Rule was updated to reflect this change. The Flight Rule and associated crew actions initially called for a single throttle step to minimum power level when a low threshold for NPSP was met. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of the additional capabilities. This paper will examine the evolution of the Flight rule and associated procedure and how increases in knowledge about the SSME and the Space Shuttle vehicle as a whole have helped shape their development. What once was a single throttle step when NPSP decreased to a certain threshold has now become three throttle steps, each occurring at a lower NPSP threshold. Additionally the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now results in a nominal Main Engine Cut Off and no loss of mission objectives.

The Evolution of Utilizing Manual Throttling to Avoid Excessively Low LH2 NPSP at the SSME Inlet

NASA Technical Reports Server (NTRS)

Henfling, Rick

2010-01-01

In the late 1970s, years before the Space Shuttle flew its maiden voyage, it was understood low liquid hydrogen (LH2) Net Positive Suction Pressure (NPSP) at the inlet to the Space Shuttle Main Engine (SSME) could have adverse effects on engine operation. A number of failures within both the External Tank (ET) and the Orbiter Main Propulsion System (MPS) could result in a low LH2 NPSP condition, which at extremely low levels can result in cavitation of SSME turbomachinery. Operational workarounds were developed to take advantage of the onboard crew s ability to manually throttle down the SSMEs (via the Pilot s Speedbrake/Throttle Controller), which alleviated the low LH2 NPSP condition. Manually throttling the SSME to a lower power level resulted in an increase in NPSP, mainly due to the reduction in frictional flow losses while at the lower throttle setting. Early in the Space Shuttle Program s history, the relevant Flight Rule for the Booster flight controller in Mission Control did not distinguish between ET and Orbiter MPS failures and the same crew action was taken for both. However, after a review of all Booster operational techniques following the Challenger disaster in the late 1980s, it was determined manually throttling the SSME to a lower power was only effective for Orbiter MPS failures and the Flight Rule was updated to reflect this change. The Flight Rule and associated crew actions initially called for a single throttle step to minimum power level when a low threshold for NPSP was met. As engineers refined their understanding of the NPSP requirements for the SSME (through a robust testing program), the operational techniques evolved to take advantage of the additional capabilities. This paper will examine the evolution of the Flight rule and associated procedure and how increases in knowledge about the SSME and the Space Shuttle vehicle as a whole have helped shape their development. What once was a single throttle step when NPSP decreased to a certain low threshold has now become three throttle steps, each occurring at a lower NPSP threshold. Additionally the procedure, which for early Space Shuttle missions required a Return-to-Launch-Site abort, now results in a nominal Main Engine Cut Off and no loss of mission objectives.

Structural Evaluation of a Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump Turbine Blade

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali

1996-01-01

Thermal and structural finite-element analyses were performed on the first high pressure fuel turbopump turbine blade of the space shuttle main engine (SSME). A two-dimensional (2-D) finite-element model of the blade and firtree disk attachment was analyzed using the general purpose MARC (finite-element) code. The loading history applied is a typical test stand engine cycle mission, which consists of a startup condition with two thermal spikes, a steady state and a shutdown transient. The blade material is a directionally solidified (DS) Mar-M 246 alloy, the blade rotor is forged with waspalloy material. Thermal responses under steady-state and transient conditions were calculated. The stresses and strains under the influence of mechanical and thermal loadings were also determined. The critical regions that exhibited high stresses and severe localized plastic deformation were the blade-rotor gaps.

Overview of aerothermodynamic loads definition study

NASA Technical Reports Server (NTRS)

Gaugler, Raymond E.

1989-01-01

Over the years, NASA has been conducting the Advanced Earth-to-Orbit (AETO) Propulsion Technology Program to provide the knowledge, understanding, and design methodology that will allow the development of advanced Earth-to-orbit propulsion systems with high performance, extended service life, automated operations, and diagnostics for in-flight health monitoring. The objective of the Aerothermodynamic Loads Definition Study is to develop methods to more accurately predict the operating environment in AETO propulsion systems, such as the Space Shuttle Main Engine (SSME) powerhead. The approach taken consists of 2 parts: to modify, apply, and disseminate existing computational fluid dynamics tools in response to current needs and to develop new technology that will enable more accurate computation of the time averaged and unsteady aerothermodynamic loads in the SSME powerhead. The software tools are detailed. Significant progress was made in the area of turbomachinery, where there is an overlap between the AETO efforts and research in the aeronautical gas turbine field.

Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5

NASA Technical Reports Server (NTRS)

Anderson, P. J.; Nussbaum, P.; Gustafson, G.

1984-01-01

The purpose of Modification No. 5 of this contract is to expand the scope of work (Task C) of this research study effort to develop pressure instrumentation for the SSME. The objective of this contract (Task C) is to direct Honeywell's Solid State Electronics Division's (SSED) extensive experience and expertise in solid state sensor technology to develop prototype pressure transducers which are targeted to meet the SSME performance design goals and to fabricate, test and deliver a total of 10 prototype units. SSED's basic approach is to effectively utilize the many advantages of silicon piezoresistive strain sensing technology to achieve the objectives of advanced state-of-the-art pressure sensors in terms of reliability, accuracy and ease of manufacture. More specifically, integration of multiple functions on a single chip is the key attribute of this technology which will be exploited during this research study.

3-D thermal analysis using finite difference technique with finite element model for improved design of components of rocket engine turbomachines for Space Shuttle Main Engine SSME

NASA Technical Reports Server (NTRS)

Sohn, Kiho D.; Ip, Shek-Se P.

1988-01-01

Three-dimensional finite element models were generated and transferred into three-dimensional finite difference models to perform transient thermal analyses for the SSME high pressure fuel turbopump's first stage nozzles and rotor blades. STANCOOL was chosen to calculate the heat transfer characteristics (HTCs) around the airfoils, and endwall effects were included at the intersections of the airfoils and platforms for the steady-state boundary conditions. Free and forced convection due to rotation effects were also considered in hollow cores. Transient HTCs were calculated by taking ratios of the steady-state values based on the flow rates and fluid properties calculated at each time slice. Results are presented for both transient plots and three-dimensional color contour isotherm plots; they were also converted into universal files to be used for FEM stress analyses.

Computational analysis of the SSME fuel preburner flow

NASA Technical Reports Server (NTRS)

Wang, T. S.; Farmer, R. C.

1986-01-01

A computational fluid dynamics model which simulates the steady state operation of the SSME fuel preburner is developed. Specifically, the model will be used to quantify the flow factors which cause local hot spots in the fuel preburner in order to recommend experiments whereby the control of undesirable flow features can be demonstrated. The results of a two year effort to model the preburner are presented. In this effort, investigating the fuel preburner flowfield, the appropriate transport equations were numerically solved for both an axisymmetric and a three-dimensional configuration. Continuum's VAST (Variational Solution of the Transport equations) code, in conjunction with the CM-1000 Engineering Analysis Workstation and the NASA/Ames CYBER 205, was used to perform the required calculations. It is concluded that the preburner operational anomalies are not due to steady state phenomena and must, therefore, be related to transient operational procedures.

Data-Rate Estimation for Autonomous Receiver Operation

NASA Technical Reports Server (NTRS)

Tkacenko, A.; Simon, M. K.

2005-01-01

In this article, we present a series of algorithms for estimating the data rate of a signal whose admissible data rates are integer base, integer powered multiples of a known basic data rate. These algorithms can be applied to the Electra radio currently used in the Deep Space Network (DSN), which employs data rates having the above relationship. The estimation is carried out in an autonomous setting in which very little a priori information is assumed. It is done by exploiting an elegant property of the split symbol moments estimator (SSME), which is traditionally used to estimate the signal-to-noise ratio (SNR) of the received signal. By quantizing the assumed symbol-timing error or jitter, we present an all-digital implementation of the SSME which can be used to jointly estimate the data rate, SNR, and jitter. Simulation results presented show that these joint estimation algorithms perform well, even in the low SNR regions typically encountered in the DSN.

A parallel strategy for implementing real-time expert systems using CLIPS

NASA Technical Reports Server (NTRS)

Ilyes, Laszlo A.; Villaseca, F. Eugenio; Delaat, John

1994-01-01

As evidenced by current literature, there appears to be a continued interest in the study of real-time expert systems. It is generally recognized that speed of execution is only one consideration when designing an effective real-time expert system. Some other features one must consider are the expert system's ability to perform temporal reasoning, handle interrupts, prioritize data, contend with data uncertainty, and perform context focusing as dictated by the incoming data to the expert system. This paper presents a strategy for implementing a real time expert system on the iPSC/860 hypercube parallel computer using CLIPS. The strategy takes into consideration not only the execution time of the software, but also those features which define a true real-time expert system. The methodology is then demonstrated using a practical implementation of an expert system which performs diagnostics on the Space Shuttle Main Engine (SSME). This particular implementation uses an eight node hypercube to process ten sensor measurements in order to simultaneously diagnose five different failure modes within the SSME. The main program is written in ANSI C and embeds CLIPS to better facilitate and debug the rule based expert system.

Hotfire testing of a SSME HPOTP with an annular hydrostatic bearing

NASA Technical Reports Server (NTRS)

Nolan, Steven A.; Hibbs, Robert I.; Genge, Gary G.

1994-01-01

A new fluid film bearing package has been tested in the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP). This fluid film element functions as both the pump end bearing and the preburner pump rear wear ring seal. Most importantly, it replaces a duplex ball bearing package which has been the primary life limiting component in the turbopump. The design and predicted performance of the turbopump are reviewed. Results are presented for measured pump and bearing performance during testing on the NASA Technology Test Bed (TTB) Engine located at MSFC. The most significant results were obtained from proximity probes located in the bearing bore which revealed large subsynchronous precession at ten percent of shaft speed during engine start which subsided prior to mainstage power levels and reappeared during engine shutdown at equivalent power levels below 65% of nominal. This phenomenon has been attributed to rotating stall in the diffuser. The proximity probes also revealed the location of the bearing in the bore for different operating speeds. Pump vibration characteristics were improved as compared to pumps tested with ball bearings. After seven starts and more than 700 seconds of testing, the pump showed no signs of performance degradation.

Bearing optimization for SSME HPOTP application

NASA Technical Reports Server (NTRS)

Armstrong, Elizabeth S.; Coe, Harold H.

1988-01-01

The space shuttle main engine (SSME) high-pressure oxygen turbopumps (HPOTP) have not experienced the service life required of them. To improve the life of the existing turbopump bearings, modifications to the bearings that could be retrofitted into the present bearing cavity are being investigated. Several bearing parameters were optimized using the computer program SHABERTH, which performs a thermomechanical simulation of a load support system. The computer analysis showed that improved bearing performance is feasible if low friction coefficients can be attained. Bearing geometries were optimized considering heat generation, equilibrium temperatures, and relative life. Two sets of curvatures were selected from the optimization: an inner-raceway curvature of 0.54, an outer-raceway curvature of 0.52, and an inner-raceway curvature of 0.55, an outer-raceway curvature of 0.53. A contact angle of 16 deg was also selected. Thermal gradients through the bearings were found to be lower with liquid lubrication than with solid film lubrication. As the coolant flowrate through the bearing increased, the ball temperature decreased but at a continuously decreasing rate. The optimum flowrate was approximately 4 kg/s. The analytical modeling used to determine these feasible modifications to improve bearing performance is described.

Vibration, acoustic, and shock design and test criteria for components on the Solid Rocket Boosters (SRB), Lightweight External Tank (LWT), and Space Shuttle Main Engines (SSME)

NASA Technical Reports Server (NTRS)

1984-01-01

The vibration, acoustics, and shock design and test criteria for components and subassemblies on the space shuttle solid rocket booster (SRB), lightweight tank (LWT), and main engines (SSME) are presented. Specifications for transportation, handling, and acceptance testing are also provided.

Closeup view of the top of Space Shuttle Main Engine ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the top of Space Shuttle Main Engine (SSME) 2057 mounted in a SSME Engine Handler in the Vertical Processing area of the SSME Processing Facility at Kennedy Space Center. The most prominent components in this view is the large Low-Pressure Oxidizer Turbopump (LPOTP) Discharge Duct wrapping itself around the right side of the engine assembly. The smaller tube to the left of LPOTP Discharge Duct is the High-Pressure Oxidizer Duct used to supply the turbine of the LPOTP. The other major feature in this view is the Low-Pressure Fuel Turbopump at the top of the engine assembly. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Preliminary vibration, acoustic, and shock design and test criteria for components on the SRB, ET, and SSME

NASA Technical Reports Server (NTRS)

1976-01-01

Specifications for vibration, acoustic and shock design for components and subassemblies on the External Tank (ET), Solid Rocket Booster (SRB), and Space Shuttle Main Engine (SSME). Included are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. The space shuttle ET, SRB, and SSME have been divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (General Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Criteria for some specific components are also presented.

An experimental investigation of rubbing interaction in labyrinth seals at cryogenic temperature

NASA Technical Reports Server (NTRS)

Dolan, F. X.; Kennedy, F. E.; Schulson, E. M.

1985-01-01

An experimental program was carried out to address issues related to the observed cracking of the titanium knife edges on the labyrinth seals of the high pressure fuel pump (HPFP) in the Space Shuttle main engine (SSME). Thermal shock experiments were carried out using a jet specimen with geometry similar to the knife edge geometry. These tests demonstrate that cracking of the titanium alloy is possible in a situation involving repeated thermal cycles over a wide temperature range, as might be realized during a rub in the liquid hydrogen fuel pump. High speed rub interaction tests were conducted using a representative knife edge and seal geometry over a broad range of interaction rates. Alternative materials were also experimentally evaluated. These tests provide information which can be used to design improved labyrinth seals for the HPFP of the SSME. In particular, plasma-sprayed aluminum-graphite was found to be significantly better than aluminum alloy seals used at present from the standpoint of rub performance. Ion nitriding of the titanium alloy knife edges was also found to improve rub performance compared with the untreated baseline knife edge material.

STS-57 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1993-01-01

The STS-57 Space Shuttle Program Mission Report provides a summary of the Payloads, as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the fifty-sixth flight of the Space Shuttle Program and fourth flight of the Orbiter vehicle Endeavour (OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET (ET-58); three SSME's which were designated as serial numbers 2019, 2034, and 2017 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-059. The lightweight RSRM's that were installed in each SRB were designated as 360L032A for the left SRB and 360W032B for the right SRB. The STS-57 Space Shuttle Program Mission Report fulfills the Space Shuttle Program requirement, as documented in NSTS 07700, Volume 8, Appendix E. That document states that each major organizational element supporting the Program will report the results of their hardware evaluation and mission performance plus identify all related in-flight anomalies.

An evaluation of GTAW-P versus GTA welding of alloy 718

NASA Technical Reports Server (NTRS)

Gamwell, W. R.; Kurgan, C.; Malone, T. W.

1991-01-01

Mechanical properties were evaluated to determine statistically whether the pulsed current gas tungsten arc welding (GTAW-P) process produces welds in alloy 718 with room temperature structural performance equivalent to current Space Shuttle Main Engine (SSME) welds manufactured by the constant current GTAW-P process. Evaluations were conducted on two base metal lots, two filler metal lots, two heat input levels, and two welding processes. The material form was 0.125-inch (3.175-mm) alloy 718 sheet. Prior to welding, sheets were treated to either the ST or STA-1 condition. After welding, panels were left as welded or heat treated to the STA-1 condition, and weld beads were left intact or machined flush. Statistical analyses were performed on yield strength, ultimate tensile strength (UTS), and high cycle fatigue (HCF) properties for all the post welded material conditions. Analyses of variance were performed on the data to determine if there were any significant effects on UTS or HCF life due to variations in base metal, filler metal, heat input level, or welding process. Statistical analyses showed that the GTAW-P process does produce welds with room temperature structural performance equivalent to current SSME welds manufactured by the GTAW process, regardless of prior material condition or post welding condition.

A History of Welding on the Space Shuttle Main Engine (1975 to 2010)

NASA Technical Reports Server (NTRS)

Zimmerman, Frank R.; Russell, Carolyn K.

2010-01-01

The Space Shuttle Main Engine (SSME) is a high performance, throttleable, liquid hydrogen fueled rocket engine. High thrust and specific impulse (Isp) are achieved through a staged combustion engine cycle, combined with high combustion pressure (approx.3000psi) generated by the two-stage pump and combustion process. The SSME is continuously throttleable from 67% to 109% of design thrust level. The design criteria for this engine maximize performance and weight, resulting in a 7,800 pound rocket engine that produces over a half million pounds of thrust in vacuum with a specific impulse of 452/sec. It is the most reliable rocket engine in the world, accumulating over one million seconds of hot-fire time and achieving 100% flight success in the Space Shuttle program. A rocket engine with the unique combination of high reliability, performance, and reusability comes at the expense of manufacturing simplicity. Several innovative design features and fabrication techniques are unique to this engine. This is as true for welding as any other manufacturing process. For many of the weld joints it seemed mean cheating physics and metallurgy to meet the requirements. This paper will present a history of the welding used to produce the world s highest performance throttleable rocket engine.

The Space Station air revitalization subsystem design concept

NASA Technical Reports Server (NTRS)

Ray, C. D.; Ogle, K. Y.; Tipps, R. W.; Carrasquillo, R. L.; Wieland, P.

1987-01-01

The current status of the Space Station (SS) Environmental Control and Life Support System (ECLSS) Air Revitalization Subsystem (ARS) design is outlined. ARS performance requirements are provided, along with subsystem options for each ARS function and selected evaluations of the relative merits of each subsystem. Detailed computer models that have been developed to analyze individual subsystem performance capabilities are also discussed. A summary of ARS subsystem level testing planned and completed by NASA Marshall Space Flight Center (MSFC) is given.

Landsat-1 and Landsat-2 flight evaluation

NASA Technical Reports Server (NTRS)

1975-01-01

The flight performance of Landsat 1 and Landsat 2 is analyzed. Flight operations of the satellites are briefly summarized. Other topics discussed include: orbital parameters; power subsystem; attitude control subsystem; command/clock subsystem; telemetry subsystem; orbit adjust subsystem; magnetic moment compensating assembly; unified s-band/premodulation processor; electrical interface subsystem; thermal subsystem; narrowband tape recorders; wideband telemetry subsystem; attitude measurement sensor; wideband video tape recorders; return beam vidicon; multispectral scanner subsystem; and data collection subsystem.

Comparing the performance of the public, social security and private health subsystems in Argentina by core dimensions of primary health care.

PubMed

Yavich, Natalia; Báscolo, Ernesto Pablo; Haggerty, Jeannie

2016-06-01

Most Latin American health systems are comprised of public (PubS), social security (SSS) and private (PrS) subsystems. These subsystems coexist, causing health care fragmentation and population segmentation. To estimate the extent of subsystem cross-coverage in a geographically bounded population (Rosario city) and to compare the subsystems' performance on primary health care (PHC) dimensions. Through a cross-sectional, interviewer-administered survey to a representative sample (n = 822) of the Rosario population, we measured the percentage of cross-coverage (people with usual source of care in one subsystem but also covered by another subsystem) and the health services' performance by core PHC dimensions, as reported by each subsystem's usual users. We compared the subsystems' performance using chi-square analysis and one-way analysis of variance testing. We analyzed whether the observed differences were coherent with the predominant institutional and organizational features of each subsystem. Overall, 39.3% of the population was affiliated with the PubS, 44.8% with the SSS and 15.9% with the PrS. Cross-coverage was reported by 40.6% of respondents. The performance of the PubS was weak on accessibility but strong on person-and-community-oriented care, the opposite of the PrS. The SSS combined the strengths of the other two subsystems. Rosario's health system has a high percentage of cross-coverage, contributing to issues of fragmentation, segmentation, financial inequity and inefficiency. The overall performance of the SSS was better than that of the PrS and PubS, though each subsystem had a particular performance pattern with areas of strength and weakness that were consistent with their institutional and organizational profiles. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Technology test bed review

NASA Technical Reports Server (NTRS)

Mcconnaughey, H. V.

1992-01-01

The topics are presented in viewgraph form and include the following: (1) Space Shuttle Main Engine (SSME) technology test bed (TTB) history; (2) TTB objectives; (3) TTB major accomplishments; (4) TTB contributions to SSME; (5) major impacts of 3001 testing; (6) some challenges to computational fluid dynamics (CFD); (7) the high pressure fuel turbopump (HPFTP); and (8) 3001 lessons learned in design and operations.

PC-403: Pioneer Venus multiprobe spacecraft mission operational characteristics document, volume 2

NASA Technical Reports Server (NTRS)

Barker, F. C.

1978-01-01

The data handling subsystem, command subsystem, communications subsystem, power subsystem, and mission operations of the Pioneer Venus multiprobe are presented. The multiprobe spacecraft performance in normal operating modes that correspond to the performance of specific functions at the time of specific events in the mission is described.

KSC-04PD-2515

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In this view from the floor of the Orbiter Processing Facility, the first of three Space Shuttle Main Engines (SSME) is seen after installation. Discovery is the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

KSC-04PD-2510

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, technicians wait below while a Hyster lift moves the first of three Space Shuttle Main Engines (SSME) into position above for installation on Discovery, the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

KSC-04PD-2516

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In this closeup view, the first of three Space Shuttle Main Engines (SSME) is seen after installation on Discovery in the Orbiter Processing Facility. Discovery is the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

KSC-04PD-2514

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, the Hyster lift backs away from the orbiter Discovery after placing a Space Shuttle Main Engine (SSME) into position for installation. Discovery is the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

KSC-04PD-2512

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, a technician (lower right) watches from inside as a Space Shuttle Main Engine (SSME) on the Hyster lift is maneuvered into position on Discovery, the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

KSC-04PD-2509

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. In the Orbiter Processing Facility, Discovery waits as the first of three Space Shuttle Main Engines (SSME) moves into position for installation on Discovery, the vehicle designated for the Return to Flight mission STS-114. Overall, an SSME weighs approximately 7,000 pounds. An SSME operates at greater temperature extremes than any mechanical system in common use today. The liquid hydrogen fuel is -423 degrees Fahrenheit, the second coldest liquid on Earth. When the hydrogen is burned with liquid oxygen, the temperature in the engine's combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of Iron. The maximum equivalent horsepower developed by the three SSMEs is just over 37 million horsepower. The energy released by the three SSMEs is equivalent to the output of 23 Hoover Dams.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 4: High pressure fuel turbo-pump inlet housing analysis

NASA Technical Reports Server (NTRS)

Pool, Kirby V.

1989-01-01

The analysis performed on the Space Shuttle Main Engine (SSME) High Pressure Fuel Turbopump (HPFTP) inlet housings is summarized. Three DIAL finite element models were build to aid in assessing the structural life of the welds and fillets at the vanes. Complete results are given.

High frequency data acquisition system for space shuttle main engine testing

NASA Technical Reports Server (NTRS)

Lewallen, Pat

1987-01-01

The high frequency data acquisition system developed for the Space Shuttle Main Engine (SSME) single engine test facility at the National Space Technology Laboratories is discussed. The real time system will provide engineering data for a complete set of SSME instrumentation (approx. 100 measurements) within 4 hours following engine cutoff, a decrease of over 48 hours from the previous analog tape based system.

[Financing, organization, costs and services performance of the Argentinean health sub-systems.

PubMed

Yavich, Natalia; Báscolo, Ernesto Pablo; Haggerty, Jeannie

2016-01-01

To analyze the relationship between health system financing and services organization models with costs and health services performance in each of Rosario's health sub-systems. The financing and organization models were characterized using secondary data. Costs were calculated using the WHO/SHA methodology. Healthcare quality was measured by a household survey (n=822). Public subsystem:Vertically integrated funding and primary healthcare as a leading strategy to provide services produced low costs and individual-oriented healthcare but with weak accessibility conditions and comprehensiveness. Private subsystem: Contractual integration and weak regulatory and coordination mechanisms produced effects opposed to those of the public sub-system. Social security: Contractual integration and strong regulatory and coordination mechanisms contributed to intermediate costs and overall high performance. Each subsystem financing and services organization model had a strong and heterogeneous influence on costs and health services performance.

Development of an integrated, zero-G pneumatic transporter/rotating-paddle incinerator/catalytic afterburner subsystem for processing human waste on board spacecraft

NASA Technical Reports Server (NTRS)

Fields, S. F.; Labak, L. J.; Honegger, R. J.

1974-01-01

A baseline laboratory prototype of an integrated, six man, zero-g subsystem for processing human wastes onboard spacecraft was investigated, and included the development of an operational specification for the baseline subsystem, followed by design and fabrication. The program was concluded by performing a series of six tests over a period of two weeks to evaluate the performance of the subsystem. The results of the tests were satisfactory, however, several changes in the design of the subsystem are required before completely satisfactory performance can be achieved.

Materials and processes for shuttle engine, external tank, and solid rocket booster

NASA Technical Reports Server (NTRS)

Schwinghamer, R. J.

1977-01-01

The Shuttle flight system is composed of the Orbiter, an External Tank (ET) that contains the ascent propellant to be used by the Space Shuttle Main Engines (SSME), and two Solid Rocket Boosters (SRB). The ET is expended on each launch; the Orbiter and SRB's are reusable. It is the requirement for reuse which poses the exciting new materials and processes challenges in the development of the Space Shuttle. A brief description of the Space Shuttle and the mission profile is given. The Shuttle configuration is then described with emphasis on the SSME, ET, and SRB. The materials selection, tracking, and control system used to assure reliability and to minimize cost are described, and salient features and challenges in materials and processes associated with the SSME, ET, and SRB are subsequently discussed.

Use of an expert system data analysis manager for space shuttle main engine test evaluation

NASA Technical Reports Server (NTRS)

Abernethy, Ken

1988-01-01

The ability to articulate, collect, and automate the application of the expertise needed for the analysis of space shuttle main engine (SSME) test data would be of great benefit to NASA liquid rocket engine experts. This paper describes a project whose goal is to build a rule-based expert system which incorporates such expertise. Experiential expertise, collected directly from the experts currently involved in SSME data analysis, is used to build a rule base to identify engine anomalies similar to those analyzed previously. Additionally, an alternate method of expertise capture is being explored. This method would generate rules inductively based on calculations made using a theoretical model of the SSME's operation. The latter rules would be capable of diagnosing anomalies which may not have appeared before, but whose effects can be predicted by the theoretical model.

STS-67 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1995-01-01

The STS-67 Space Shuttle Program Mission Report provides the results of the orbiter vehicle performance evaluation during this sixty-eighth flight of the Shuttle Program, the forty-third flight since the return to flight, and the eighth flight of the Orbiter vehicle Endeavour (OV-105). In addition, the report summarizes the payload activities and the performance of the External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle Main Engines (SSME). The serial numbers of the other elements of the flight vehicle were ET-69 for the ET; 2012, 2033, and 2031 for SSME's 1, 2, and 3, respectively; and Bl-071 for the SRB's. The left-hand RSRM was designated 360W043A, and the right-hand RSRM was designated 360L043B. The primary objective of this flight was to successfully perform the operations of the ultraviolet astronomy (ASTRO-2) payload. Secondary objectives of this flight were to complete the operations of the Protein Crystal Growth - Thermal Enclosure System (PCG-TES), the Protein Crystal Growth - Single Locker Thermal Enclosure System (PCG-STES), the Commercial Materials Dispersion Apparatus ITA Experiments (CMIX), the Shuttle Amateur Radio Experiment-2 (SAREX-2), the Middeck Active Control Experiment (MACE), and two Get-Away Special (GAS) payloads.

Duct flow nonuniformities: Effect of struts in SSME HGM II(+)

NASA Technical Reports Server (NTRS)

Burke, Roger

1988-01-01

A numerical study, using the INS3D flow solver, of laminar and turbulent flow around a two dimensional strut, and three dimensional flow around a strut in an annulus is presented. A multi-block procedure was used to calculate two dimensional laminar flow around two struts in parallel, with each strut represented by one computational block. Single block calculations were performed for turbulent flow around a two dimensional strut, using a Baldwin-Lomax turbulence model to parameterize the turbulent shear stresses. A modified Baldwin-Lomax model was applied to the case of a three dimensional strut in an annulus. The results displayed the essential features of wing-body flows, including the presence of a horseshoe vortex system at the junction of the strut and the lower annulus surface. A similar system was observed at the upper annulus surface. The test geometries discussed were useful in developing the capability to perform multiblock calculations, and to simulate turbulent flow around obstructions located between curved walls. Both of these skills will be necessary to model the three dimensional flow in the strut assembly of the SSME. Work is now in progress on performing a three dimensional two block turbulent calculation of the flow in the turnaround duct (TAD) and strut/fuel bowl juncture region.

Integrated Advance Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: EOS AMSU-A1 and AMSU-A2 Receivers Assemblies

NASA Technical Reports Server (NTRS)

2000-01-01

This test report presents the test data of the EOS AMSU-A Flight Model No.1 (FM-1) receiver subsystem. The tests are performed per the Acceptance Test Procedure for the AMSU-A Reseiver Subsystem, AE-26002/6A. The functional performance tests are conducted either at the component or subsystem level. While the component-level tests are performed over the entire operating temperature range predicted by thermal analysis, the subsystem-level test are conducted at ambient temperature only.

Analysis of SSEM Sensor Data Using BEAM

NASA Technical Reports Server (NTRS)

Zak, Michail; Park, Han; James, Mark

2004-01-01

A report describes analysis of space shuttle main engine (SSME) sensor data using Beacon-based Exception Analysis for Multimissions (BEAM) [NASA Tech Briefs articles, the two most relevant being Beacon-Based Exception Analysis for Multimissions (NPO- 20827), Vol. 26, No.9 (September 2002), page 32 and Integrated Formulation of Beacon-Based Exception Analysis for Multimissions (NPO- 21126), Vol. 27, No. 3 (March 2003), page 74] for automated detection of anomalies. A specific implementation of BEAM, using the Dynamical Invariant Anomaly Detector (DIAD), is used to find anomalies commonly encountered during SSME ground test firings. The DIAD detects anomalies by computing coefficients of an autoregressive model and comparing them to expected values extracted from previous training data. The DIAD was trained using nominal SSME test-firing data. DIAD detected all the major anomalies including blade failures, frozen sense lines, and deactivated sensors. The DIAD was particularly sensitive to anomalies caused by faulty sensors and unexpected transients. The system offers a way to reduce SSME analysis time and cost by automatically indicating specific time periods, signals, and features contributing to each anomaly. The software described here executes on a standard workstation and delivers analyses in seconds, a computing time comparable to or faster than the test duration itself, offering potential for real-time analysis.

SSME Main Combustion Chamber (MCC) hot oil dewaxing

NASA Technical Reports Server (NTRS)

Akpati, Anthony U.

1995-01-01

In an attempt to comply with the changing environmental regulations, a process was developed for the replacement of perchloroethylene in the dewaxing of the Space Shuttle Main Engine (SSME) Main Combustion Chamber (MCC) and other associated hardware filled with the Rigidax (R) casting compound. Rigidax (R) is a hard blue-dyed, calcium carbonate filled thermoplastic casting compound (melting point 77 C) that is melted and poured into hardware cavities to prevent contamination during material removal processes, i.e. machining, grinding, drilling, and deburring. Additionally, it serves as a maskant for designated areas during electroforming processes. Laboratory testing was conducted to evaluate seven alternate fluids for the replacement of perchloroethylene in the dewaxing process. Based upon successful laboratory results, a mineral oil was selected for testing on actual hardware. The final process developed involves simultaneous immersion and flushing of the MCC channels using a distinct eight stage process. A nonvolatile hydrocarbon analysis of a solvent flush sample is performed to determine the hardware cleanliness for comparison to the previous perchloroethylene dewaxing process.

The determination of equivalent bearing loading for the BSMT that simulate SSME high pressure oxidizer turbopump conditions using the SHABERTH/SINDA computer programs

NASA Technical Reports Server (NTRS)

Mcdonald, Gary H.

1987-01-01

The MSFC bearing seal material tester (BSMT) can be used to evaluate the SSME high pressure oxygen turbopump (HPOTP) bearing performance. The four HPOTP bearings have both an imposed radial and axial load. These radial and axial loads are caused by the HPOTP's shaft, main impeller, preburner impeller, turbine and by the LOX coolant flow through the bearings, respectively. These loads coupled with bearing geometry and operating speed can define bearing contact angle, contact Hertz stress, and heat generation rates. The BSMT has the capability of operating at HPOTP shaft speeds, provide proper coolant flowrates but can only apply an axial load. Due to the inability to operate the bearings in the BSMT with an applied radial load, it is important to develop an equivalency between the applied axial loads and the actual HPOTP loadings. A shaft-bearing-thermal computer code (SHABERTH/SINDA) is used to simulate the BSMT bearing-shaft geometry and thermal-fluid operating conditions.

SSME Main Combustion Chamber (MCC) 'Hot Oil' Dewaxing

NASA Technical Reports Server (NTRS)

Akpati, Anthony U.

1994-01-01

In an attempt to comply with the changing environmental regulations, a process was developed for the replacement of perchloroethylene in the dewaxing of the Space Shuttle Main Engine (SSME) Main Combustion Chamber (MCC) and other associated hardware filled with the Rigidax(registered mark) casting compound. Rigidax(registered mark) is a hard blue-dyed, calcium carbonate filled thermoplastic casting compound (melting point 77 C) that is melted and poured into hardware cavities to prevent contamination during material removal processes, i.e. machining, grinding, drilling, and deburring. Additionally, it serves as a maskant for designated areas during electroforming processes. Laboratory testing was conducted to evaluate seven alternate fluids for the replacement of perchloroethylene in the dewaxing process. Based upon successful laboratory results, a mineral oil was selected for testing on actual hardware. The final process developed involves simultaneous immersion and flushing of the MCC channels using a distinct eight stage process. A nonvolatile hydrocarbon analysis of a solvent flush sample is performed to determine the hardware cleanliness for comparison to the previous perchloroethylene dewaxing process.

STS-73 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1995-01-01

The STS-73 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-second flight of the Space Shuttle Program, the forty-seventh flight since the return-to-flight, and the eighteenth flight of the Orbiter Columbia (OV-102). STS-73 was also the first flight of OV-102 following the vehicle's return from the Orbiter Maintenance Down Period (OMDP). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-73; three SSME's that were designated as serial numbers 2037 (Block 1), 2031 (PH-1), and 2038 (Block 1) in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-075. The RSRM's, designated RSRM-50, were installed in each SRB and the individual RSRM's were designated as 36OL050A for the left SRB, and 36OW050B for the right SRB. The primary objective of this flight was to successfully perform the planned operations of the United States Microgravity Laboratory (USML)-2 payload.

Space Shuttle Main Engine structural analysis and data reduction/evaluation. Volume 6: Primary nozzle diffuser analysis

NASA Technical Reports Server (NTRS)

Foley, Michael J.

1989-01-01

The primary nozzle diffuser routes fuel from the main fuel valve on the Space Shuttle Main Engine (SSME) to the nozzle coolant inlet mainfold, main combustion chamber coolant inlet mainfold, chamber coolant valve, and the augmented spark igniters. The diffuser also includes the fuel system purge check valve connection. A static stress analysis was performed on the diffuser because no detailed analysis was done on this part in the past. Structural concerns were in the area of the welds because approximately 10 percent are in areas inaccessible by X-ray testing devices. Flow dynamics and thermodynamics were not included in the analysis load case. Constant internal pressure at maximum SSME power was used instead. A three-dimensional, finite element method was generated using ANSYS version 4.3A on the Lockheed VAX 11/785 computer to perform the stress computations. IDEAS Supertab on a Sun 3/60 computer was used to create the finite element model. Rocketdyne drawing number RS009156 was used for the model interpretation. The flight diffuser is denoted as -101. A description of the model, boundary conditions/load case, material properties, structural analysis/results, and a summary are included for documentation.

Comparing the performance of the public, social security and private health subsystems in Argentina by core dimensions of primary health care

PubMed Central

Yavich, Natalia; Báscolo, Ernesto Pablo; Haggerty, Jeannie

2016-01-01

Abstract Background Most Latin American health systems are comprised of public (PubS), social security (SSS) and private (PrS) subsystems. These subsystems coexist, causing health care fragmentation and population segmentation. Objective To estimate the extent of subsystem cross-coverage in a geographically bounded population (Rosario city) and to compare the subsystems’ performance on primary health care (PHC) dimensions. Methods Through a cross-sectional, interviewer-administered survey to a representative sample (n = 822) of the Rosario population, we measured the percentage of cross-coverage (people with usual source of care in one subsystem but also covered by another subsystem) and the health services’ performance by core PHC dimensions, as reported by each subsystem’s usual users. We compared the subsystems’ performance using chi-square analysis and one-way analysis of variance testing. We analyzed whether the observed differences were coherent with the predominant institutional and organizational features of each subsystem. Results Overall, 39.3% of the population was affiliated with the PubS, 44.8% with the SSS and 15.9% with the PrS. Cross-coverage was reported by 40.6% of respondents. The performance of the PubS was weak on accessibility but strong on person-and-community-oriented care, the opposite of the PrS. The SSS combined the strengths of the other two subsystems. Conclusion Rosario’s health system has a high percentage of cross-coverage, contributing to issues of fragmentation, segmentation, financial inequity and inefficiency. The overall performance of the SSS was better than that of the PrS and PubS, though each subsystem had a particular performance pattern with areas of strength and weakness that were consistent with their institutional and organizational profiles. PMID:27377651

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 10. Subsystem Performance Requirements.

DOT National Transportation Integrated Search

1974-02-01

The volume presents the results of the subsystem performance requirements study for an Advanced Air Traffic Management System (AATMS). The study determined surveillance and navigation subsystem requirements for terminal and enroute area operations. I...

STS-47 Pilot Brown on OV-105's flight deck ten minutes after SSME cutoff

NASA Technical Reports Server (NTRS)

1992-01-01

STS-47 Pilot Curtis L. Brown, Jr, is photographed at Endeavour's, Orbiter Vehicle (OV) 105's, pilot station about ten minutes after space shuttle main engine (SSME) cutoff on launch day. Brown smiles from inside the launch and entry suit (LES) and launch and entry helmet (LEH). In the background are the flight mirror assembly silhouetted against forward window W5, control panels, and a checklist.

Radial basis function neural networks applied to NASA SSME data

NASA Technical Reports Server (NTRS)

Wheeler, Kevin R.; Dhawan, Atam P.

1993-01-01

This paper presents a brief report on the application of Radial Basis Function Neural Networks (RBFNN) to the prediction of sensor values for fault detection and diagnosis of the Space Shuttle's Main Engines (SSME). The location of the Radial Basis Function (RBF) node centers was determined with a K-means clustering algorithm. A neighborhood operation about these center points was used to determine the variances of the individual processing notes.

Closeup view of a Space Shuttle Main Engine (SSME) installed ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of a Space Shuttle Main Engine (SSME) installed in position number one on the Orbiter Discovery. A ground-support mobile platform is in place below the engine to assist in technicians with the installation of the engine. This Photograph was taken in the Orbiter Processing Facility at the Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

SSME environment database development

NASA Technical Reports Server (NTRS)

Reardon, John

1987-01-01

The internal environment of the Space Shuttle Main Engine (SSME) is being determined from hot firings of the prototype engines and from model tests using either air or water as the test fluid. The objectives are to develop a database system to facilitate management and analysis of test measurements and results, to enter available data into the the database, and to analyze available data to establish conventions and procedures to provide consistency in data normalization and configuration geometry references.

An SSME High Pressure Oxidizer Turbopump diagnostic system using G2 real-time expert system

NASA Technical Reports Server (NTRS)

Guo, Ten-Huei

1991-01-01

An expert system which diagnoses various seal leakage faults in the High Pressure Oxidizer Turbopump of the SSME was developed using G2 real-time expert system. Three major functions of the software were implemented: model-based data generation, real-time expert system reasoning, and real-time input/output communication. This system is proposed as one module of a complete diagnostic system for the SSME. Diagnosis of a fault is defined as the determination of its type, severity, and likelihood. Since fault diagnosis is often accomplished through the use of heuristic human knowledge, an expert system based approach has been adopted as a paradigm to develop this diagnostic system. To implement this approach, a software shell which can be easily programmed to emulate the human decision process, the G2 Real-Time Expert System, was selected. Lessons learned from this implementation are discussed.

Vibration characteristics of the HPOTP (High-Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine)

NASA Technical Reports Server (NTRS)

Childs, D. W.; Moyer, D. S.

1984-01-01

Attention is given to rotor dynamic problems that have been encountered and eliminated in the course of Space Shuttle Main Engine (SSME) development, as well as continuing, subsynchronous problems which are being encountered in the development of a 109-percent power level engine. The basic model for the SSME's High Pressure Oxygen Turbopump (HPOTP) encompasses a structural dynamic model for the rotor and housing, and component models for the liquid and gas seals, turbine clearance excitation forces, and impeller diffuser forces. Linear model results are used to examine the synchronous response and stability characteristics of the HPOTP, with attention to bearing load and stability problems associated with the second critical speed. Differences between linear and nonlinear model results are discussed and explained in terms of simple models. Simulation results indicate that while synchronous bearing loads can be reduced, subsynchronous motion is not eliminated by seal modifications.

X-ray spectroscopy of the SSME plume

NASA Technical Reports Server (NTRS)

Olive, Dan F.

1988-01-01

In order to examine the potential of using SSME exhaust plume radiation in the soft X-ray spectrum as an early warning system of imminent engine failure, a low cost, low risk experiment was devised. An approach was established, equipment was leased, the system was installed and checked out, and data were successfully acquired demonstrating the proof-of-concept. One spectrum measurement of the SSME plume was acquired during a 300 second burn on the A-1 Test Stand. This spectrum showed a prominent, line emission feature at about 34.5 KeV, a result which was not expected, nor can it be explained at this time. If X-ray spectra are to be useful as a means of monitoring nominal engine operation, it will be necessary to explore this region of the EM spectrum in greater detail. The presence of structure in the spectrum indicates that this technology may prove to be useful as an engine health monitoring system.

Flow dynamic environment data base development for the SSME

NASA Technical Reports Server (NTRS)

Sundaram, C. V.

1985-01-01

The fluid flow-induced vibration of the Space Shuttle main engine (SSME) components are being studied with a view to correlating the frequency characteristics of the pressure fluctuations in a rocket engine to its operating conditions and geometry. An overview of the data base development for SSME test firing results and the interactive computer software used to access, retrieve, and plot or print the results selectively for given thrust levels, engine numbers, etc., is presented. The various statistical methods available in the computer code for data analysis are discussed. Plots of test data, nondimensionalized using parameters such as fluid flow velocities, densities, and pressures, are presented. Results are compared with those available in the literature. Correlations between the resonant peaks observed at higher frequencies in power spectral density plots with pump geometry and operating conditions are discussed. An overview of the status of the investigation is presented and future directions are discussed.

Orbital maneuvering subsystem functional path analysis for performance monitoring fault detection and annunciation

NASA Technical Reports Server (NTRS)

Keesler, E. L.

1974-01-01

The functional paths of the Orbital Maneuver Subsystem (OMS) is defined. The operational flight instrumentation required for performance monitoring, fault detection, and annunciation is described. The OMS is a pressure fed rocket engine propulsion subsystem. One complete OMS shares each of the two auxiliary propulsion subsystem pods with a reaction control subsystem. Each OMS is composed of a pressurization system, a propellant tanking system, and a gimbaled rocket engine. The design, development, and operation of the system are explained. Diagrams of the system are provided.

Vacuum application of thermal barrier plasma coatings

NASA Technical Reports Server (NTRS)

Holmes, R. R.; Mckechnie, T. N.

1988-01-01

Coatings are presently applied to Space Shuttle Main Engine (SSME) turbine blades for protection against the harsh environment realized in the engine during lift off-to-orbit. High performance nickel, chromium, aluminum, and yttrium (NiCrAlY) alloy coatings, which are applied by atmospheric plasma spraying, crack and spall off because of the severe thermal shock experienced during start-up and shut-down of the engine. Ceramic coatings of yttria stabilized zirconia (ZrO2-Y2O3) were applied initially as a thermal barrier over coating to the NiCrAlY but were removed because of even greater spalling. Utilizing a vacuum plasma spraying process, bond coatings of NiCrAlY were applied in a low pressure atmosphere of argon/helium, producing significantly improved coating-to-blade bonding. The improved coatings showed no spalling after 40 MSFC burner rig thermal shock cycles, cycling between 1700 and -423 F. The current atmospheric plasma NiCrAlY coatings spalled during 25 test cycles. Subsequently, a process was developed for applying a durable thermal barrier coating of ZrO2-Y2O3 to the turbine blades of first stage high-pressure fuel turbopumps utilizing the vacuum plasma process. The improved thermal barrier coating has successfully passed 40 burner rig thermal shock cycles without spalling. Hot firing in an SSME turbine engine is scheduled for the blades. Tooling was installed in preparation for vacuum plasma spray coating other SSME hardware, e.g., the titanium main fuel valve housing (MFVH) and the fuel turbopump nozzle/stator.

Mariner Mars 1971 attitude control subsystem flight performance

NASA Technical Reports Server (NTRS)

Schumacher, L.

1973-01-01

The flight performance of the Mariner 71 attitude control subsystem is discussed. Each phase of the mission is delineated and the attitude control subsystem is evaluated within the observed operational environment. Performance anomalies are introduced and discussed within the context of general performance. Problems such as the sun sensor interface incompatibility, gas valve leaks, and scan platform dynamic coupling effects are given analytical considerations.

Development and Capabilities of ISS Flow Boiling and Condensation Experiment

NASA Technical Reports Server (NTRS)

Nahra, Henry; Hasan, Mohammad; Balasubramaniam, R.; Patania, Michelle; Hall, Nancy; Wagner, James; Mackey, Jeffrey; Frankenfield, Bruce; Hauser, Daniel; Harpster, George;

Hybrid bearings for LH2 and LO2 turbopumps

NASA Technical Reports Server (NTRS)

Butner, M. F.; Lee, F. C.

1985-01-01

Hybrid combinations of hydrostatic and ball bearings can improve bearing performance for liquid hydrogen and liquid oxygen turbopumps. Analytic studies were conducted to optimize hybrid bearing designs for the SSME-type turbopump conditions. A method to empirically determine damping coefficients was devised. Four hybrid bearing configurations were designed, and three were fabricated. Six hybrid and hydrostatic-only bearing configurations will be tested for steady-state and transient performance, and quantification of damping coefficients. The initial tests were conducted with the liquid hydrogen bearing.

STS-80 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1997-01-01

The STS-80 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the eightieth flight of the Space Shuttle Program, the fifty-fifth flight since the return-to-flight, and the twenty-first flight of the Orbiter Columbia (OV-102).

Modular space station phase B extension, preliminary system design. Volume 4: Subsystems analyses

NASA Technical Reports Server (NTRS)

Antell, R. W.

1972-01-01

The subsystems tradeoffs, analyses, and preliminary design results are summarized. Analyses were made of the structural and mechanical, environmental control and life support, electrical power, guidance and control, reaction control, information, and crew habitability subsystems. For each subsystem a summary description is presented including subsystem requirements, subsystem description, and subsystem characteristics definition (physical, performance, and interface). The major preliminary design data and tradeoffs or analyses are described in detail at each of the assembly levels.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report, METSAT (S/N:107) AMSU-A1 Receiver Assemblies: P/N 1356429-1, S/N:F04, P/N 1356409-1,S/N F04

NASA Technical Reports Server (NTRS)

Pines, D.

1999-01-01

This is the Performance Verification Report, METSAT (S/N: 107) AMSU-A1 Receiver Assemblies, P/N 1356429-1, SIN: F04, P/N 1356409- 1, S/N: F04, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The AMSU-A receiver subsystem comprises two separated receiver assemblies; AMSU-A1 and AMSU-A2 (P/N 1356441-1). The AMSU-A1 receiver contains 13 channels and the AMSU-A2 receiver 2 channels. The AMSU-A receiver assembly is further divided into two parts; AMSU-A I - I (P/N 13 5 6429- 1) and AMSU-A 1 -2 (P/N 1356409-1), which contain 9 and 4 channels, respectively. The AMSU-A receiver subsystem is located in between the antenna and signal processing subsystems of the AMSU-A instrument and comprises the RF and IF components from isolators to attenuators. It receives the RF signals from the antenna subsystem, down-converts the RF signals to IF signals, amplifies and defines the IF signals to proper power level and frequency bandwidth as specified for each channel, and inputs the IF signals to the signal processing subsystem. The test reports for the METSAT AMSU-A receiver subsystem are prepared separately for Al and A2 receivers so that each receiver stands alone during integration of instruments into the spacecraft. This test report presents the test data of the N4ETSAT AMSU-A1 Flight Model No. 4 (FM-4) receiver subsystem. The tests are performed per the Acceptance Test Procedure (ATP) for the AMSU-A Receiver Subsystem, AE-26002/6A. The functional performance tests are conducted either at the component or subsystem level. While the component-level tests are performed over the entire operating temperature range predicted by thermal analysis, most subsystem-level tests are conducted at ambient temperature only. Key performances (bandpass characteristics and noise figure) of the receiver subsystem are verified over the operating temperature.

Advanced Vacuum Plasma Spray (VPS) for a Robust, Longlife and Safe Space Shuttle Main Engine (SSME)

NASA Technical Reports Server (NTRS)

Holmes, Richard R.; Elam, Sandra K.; McKechnie, Timothy N.; Power, Christopher A.

2010-01-01

In 1984, the Vacuum Plasma Spray Lab was built at NASA/Marshall Space Flight Center for applying durable, protective coatings to turbine blades for the space shuttle main engine (SSME) high pressure fuel turbopump. Existing turbine blades were cracking and breaking off after five hot fire tests while VPS coated turbine blades showed no wear or cracking after 40 hot fire tests. Following that, a major manufacturing problem of copper coatings peeling off the SSME Titanium Main Fuel Valve Housing was corrected with a tenacious VPS copper coating. A patented VPS process utilizing Functional Gradient Material (FGM) application was developed to build ceramic lined metallic cartridges for space furnace experiments, safely containing gallium arsenide at 1260 degrees centigrade. The VPS/FGM process was then translated to build robust, long life, liquid rocket combustion chambers for the space shuttle main engine. A 5K (5,000 Lb. thrust) thruster with the VPS/FGM protective coating experienced 220 hot firing tests in pristine condition with no wear compared to the SSME which showed blanching (surface pulverization) and cooling channel cracks in less than 30 of the same hot firing tests. After 35 of the hot firing tests, the injector face plates disintegrated. The VPS/FGM process was then applied to spraying protective thermal barrier coatings on the face plates which showed 50% cooler operating temperature, with no wear after 50 hot fire tests. Cooling channels were closed out in two weeks, compared to one year for the SSME. Working up the TRL (Technology Readiness Level) to establish the VPS/FGM process as viable technology, a 40K thruster was built and is currently being tested. Proposed is to build a J-2X size liquid rocket engine as the final step in establishing the VPS/FGM process TRL for space flight.

Applications Technology Satellite ATS-6 experiment checkout and continuing spacecraft evaluation report

NASA Technical Reports Server (NTRS)

Moore, W.; Prensky, W. (Editor)

1974-01-01

The activities of the ATS-6 spacecraft are reviewed. The following subsystems and experiments are summarized: (1) radio beacon experiments; (2) spacecraft attitude precision pointing and slewing adaptive control experiment; (3) satellite instruction television experiment; (4) thermal control subsystem; (5) spacecraft propulsion subsystem; (6) telemetry and control subsystem; (7) millimeter wave experiment; and (8) communications subsystem. The results of performance evaluation of its subsystems and experiments are presented.

The human operator transfer function: Identification of the limb mechanics subsystem

NASA Technical Reports Server (NTRS)

Jones, Lynette A.; Hunter, Ian W.

1991-01-01

The objective of our research is to decompose the performance of the human operator in terms of the subsystems that determine the operator's responses in order to establish how the dynamics of these component subsystems influence the operator's performance. In the present experiment, the dynamic stiffness of the human elbow joint was measured at rest and under different levels of biceps muscle activation; this work forms part of the analysis of the limb mechanics subsystem.

Evolutionary computing for the design search and optimization of space vehicle power subsystems

NASA Technical Reports Server (NTRS)

Kordon, Mark; Klimeck, Gerhard; Hanks, David; Hua, Hook

2004-01-01

Evolutionary computing has proven to be a straightforward and robust approach for optimizing a wide range of difficult analysis and design problems. This paper discusses the application of these techniques to an existing space vehicle power subsystem resource and performance analysis simulation in a parallel processing environment. Out preliminary results demonstrate that this approach has the potential to improve the space system trade study process by allowing engineers to statistically weight subsystem goals of mass, cost and performance then automatically size power elements based on anticipated performance of the subsystem rather than on worst-case estimates.

ATS-6 engineering performance report. Volume:Program and systems summaries: Mechanical and thermal details

NASA Technical Reports Server (NTRS)

Wales, R. O. (Editor)

1981-01-01

The overall mission and spacecraft systems, testing, and operations are summarized. The mechanical subsystems are reviewed, encompassing mechanical design requirements; separation and deployment mechanisms; design and performance evaluation; and the television camera reflector monitor. Thermal control and contamination are discussed in terms of thermal control subsystems, design validation, subsystems performance, the advanced flight experiment, and the quartz-crystal microbalance contamination monitor.

Stennis Space Center's approach to liquid rocket engine health monitoring using exhaust plume diagnostics

NASA Technical Reports Server (NTRS)

Gardner, D. G.; Tejwani, G. D.; Bircher, F. E.; Loboda, J. A.; Van Dyke, D. B.; Chenevert, D. J.

1991-01-01

Details are presented of the approach used in a comprehensive program to utilize exhaust plume diagnostics for rocket engine health-and-condition monitoring and assessing SSME component wear and degradation. This approach incorporates both spectral and video monitoring of the exhaust plume. Video monitoring provides qualitative data for certain types of component wear while spectral monitoring allows both quantitative and qualitative information. Consideration is given to spectral identification of SSME materials and baseline plume emissions.

Tripropellant engine study

NASA Technical Reports Server (NTRS)

Wheeler, D. B.; Kirby, F. M.

1978-01-01

The potential for converting the space shuttle main engine (SSME) to a dual-fuel, dual-mode engine using LOX/hydrocarbon propellants in mode 1 and LOX/H2 in mode 2 was examined. Various engine system concepts were formulated that included staged combustion and gas generator turbine power cycles, and LOX/RP-1, LOX/CH4, and LOX/C3H8 mode 1 propellants. Both oxidizer and fuel regenerative cooling were considered. All of the SSME major components were examined to determine their adaptability to the candidate dual-fuel engines.

Advanced helium purge seals for Liquid Oxygen (LOX) turbopumps

NASA Technical Reports Server (NTRS)

Shapiro, Wilbur; Lee, Chester C.

1989-01-01

Program objectives were to determine three advanced configurations of helium buffer seals capable of providing improved performance in a space shuttle main engine (SSME), high-pressure liquid oxygen (LOX) turbopump environment, and to provide NASA with the analytical tools to determine performance of a variety of seal configurations. The three seal designs included solid-ring fluid-film seals often referred to as floating ring seals, back-to-back fluid-film face seals, and a circumferential sectored seal that incorporated inherent clearance adjustment capabilities. Of the three seals designed, the sectored seal is favored because the self-adjusting clearance features accommodate the variations in clearance that will occur because of thermal and centrifugal distortions without compromising performance. Moreover, leakage can be contained well below the maximum target values; minimizing leakage is important on the SSME since helium is provided by an external tank. A reduction in tank size translates to an increase in payload that can be carried on board the shuttle. The computer codes supplied under this program included a code for analyzing a variety of gas-lubricated, floating ring, and sector seals; a code for analyzing gas-lubricated face seals; a code for optimizing and analyzing gas-lubricated spiral-groove face seals; and a code for determining fluid-film face seal response to runner excitations in as many as five degrees of freedom. These codes proved invaluable for optimizing designs and estimating final performance of the seals described.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: EOS AMSU-A1 and AMSU-A2 Receiver Assemblies

NASA Technical Reports Server (NTRS)

Ma, Y.

1995-01-01

The AMSU-A receiver subsystem comprises two separated receiver assemblies; AMSU-A1 and AMSU-A2 (P/N 1356441-1). The AMSU-A1 receiver contains 13 channels and the AMSU-A2 receiver 2 channels. The AMSU-A1 receiver assembly is further divided into two parts; AMSU-A1-1 (P/N 1356429-1) and AMSU-A1-2 (P/N 1356409-1), which contain 9 and 4 channels, respectively. The receiver assemblies are highlighted and illustrate the functional block diagrams of the AMSU-A1 and AMSU-A2 systems. The AMSU-A receiver subsystem stands in between the antenna and signal processing subsystems of the AMSU-A instrument and comprises the RF and IF components from isolators to attenuators. It receives the RF signals from the antenna subsystem, down-converts the RF signals to IF signals, amplifies and defines the IF signals to proper power level and frequency bandwidth as specified for each channel, and inputs the IF signals to the signal processing subsystem. This test report presents the test data of the EOS AMSU-A Flight Model No. 1 (FM-1) receiver subsystem. The tests are performed per the Acceptance Test Procedure for the AMSU-A Receiver Subsystem, AE-26002/6A. The functional performance tests are conducted either at the component or subsystem level. While the component-level tests are performed over the entire operating temperature range predicted by thermal analysis, the subsystem-level tests are conducted at ambient temperature only.

Functional Performance of an Enabling Atmosphere Revitalization Subsystem Architecture for Deep Space Exploration Missions

NASA Technical Reports Server (NTRS)

Perry, Jay L.; Abney, Morgan B.; Frederick, Kenneth R.; Greenwood, Zachary W.; Kayatin, Matthew J.; Newton, Robert L.; Parrish, Keith J.; Roman, Monsi C.; Takada, Kevin C.; Miller, Lee A.;

TVC actuator model. [for the space shuttle main engine

NASA Technical Reports Server (NTRS)

Baslock, R. W.

1977-01-01

A prototype Space Shuttle Main Engine (SSME) Thrust Vector Control (TVC) Actuator analog model was successfully completed. The prototype, mounted on five printed circuit (PC) boards, was delivered to NASA, checked out and tested using a modular replacement technique on an analog computer. In all cases, the prototype model performed within the recording techniques of the analog computer which is well within the tolerances of the specifications.

Simulation of multistage turbine flows

NASA Technical Reports Server (NTRS)

Adamczyk, John J.; Mulac, Richard A.

1987-01-01

A flow model has been developed for analyzing multistage turbomachinery flows. This model, referred to as the average passage flow model, describes the time-averaged flow field with a typical passage of a blade row embedded within a multistage configuration. Computer resource requirements, supporting empirical modeling, formulation code development, and multitasking and storage are discussed. Illustrations from simulations of the space shuttle main engine (SSME) fuel turbine performed to date are given.

Probabilistic structural analysis methods for improving Space Shuttle engine reliability

NASA Technical Reports Server (NTRS)

Boyce, L.

1989-01-01

Probabilistic structural analysis methods are particularly useful in the design and analysis of critical structural components and systems that operate in very severe and uncertain environments. These methods have recently found application in space propulsion systems to improve the structural reliability of Space Shuttle Main Engine (SSME) components. A computer program, NESSUS, based on a deterministic finite-element program and a method of probabilistic analysis (fast probability integration) provides probabilistic structural analysis for selected SSME components. While computationally efficient, it considers both correlated and nonnormal random variables as well as an implicit functional relationship between independent and dependent variables. The program is used to determine the response of a nickel-based superalloy SSME turbopump blade. Results include blade tip displacement statistics due to the variability in blade thickness, modulus of elasticity, Poisson's ratio or density. Modulus of elasticity significantly contributed to blade tip variability while Poisson's ratio did not. Thus, a rational method for choosing parameters to be modeled as random is provided.

Evaluation of bearing mounting design and excessive wear phenomena

NASA Technical Reports Server (NTRS)

Kannel, J. W.

1982-01-01

The effect of bearing thermal growth on the effectiveness of the bearing preload springs on the space shuttle main engine high pressure oxygen turbopump (SSME HPTOP) were examined. The SSME HPTOP turbine end bearings, preload spring, and bearing mounting design were evaluated relative to spalling, excessive ball wear, possible thermal problems, and cage delamination. The magnitude of the thermal stresses required to cause high levels of ball wear were calculated. Plots of maximum sheer stress and maximum reversing shear versus the axial load for the 57 mm SSME HPTOP bearing were created. A plot of the bearing thermal growth versus preload spring deflection was generated. It was determined that metallic wear, rather than thermal growth, caused enlargement of the contact zone between ball and races, that high fatigue-inducing shear stresses are generated under increased loads, and that at temperatures between 100 and 150 deg C, the springs bottom out and very high loads are developed in the bearing. Allowance for adequate spring movement after assembly is recommended.

Air and water quality monitor assessment of life support subsystems

NASA Technical Reports Server (NTRS)

Whitley, Ken; Carrasquillo, Robyn L.; Holder, D.; Humphries, R.

1988-01-01

Preprotype air revitalization and water reclamation subsystems (Mole Sieve, Sabatier, Static Feed Electrolyzer, Trace Contaminant Control, and Thermoelectric Integrated Membrane Evaporative Subsystem) were operated and tested independently and in an integrated arrangement. During each test, water and/or gas samples were taken from each subsystem so that overall subsystem performance could be determined. The overall test design and objectives for both subsystem and integrated subsystem tests were limited, and no effort was made to meet water or gas specifications. The results of chemical analyses for each of the participating subsystems are presented along with other selected samples which were analyzed for physical properties and microbiologicals.

14 CFR 25.1435 - Hydraulic systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

... on the hydraulic system(s), and/or subsystem(s) and elements, except that analysis may be used in place of or to supplement testing, where the analysis is shown to be reliable and appropriate. All... system(s), subsystem(s), or element(s) must be subjected to performance, fatigue, and endurance tests...

14 CFR 25.1435 - Hydraulic systems.

Code of Federal Regulations, 2011 CFR

2011-01-01

... on the hydraulic system(s), and/or subsystem(s) and elements, except that analysis may be used in place of or to supplement testing, where the analysis is shown to be reliable and appropriate. All... system(s), subsystem(s), or element(s) must be subjected to performance, fatigue, and endurance tests...

14 CFR 25.1435 - Hydraulic systems.

Code of Federal Regulations, 2014 CFR

2014-01-01

... on the hydraulic system(s), and/or subsystem(s) and elements, except that analysis may be used in place of or to supplement testing, where the analysis is shown to be reliable and appropriate. All... system(s), subsystem(s), or element(s) must be subjected to performance, fatigue, and endurance tests...

14 CFR 25.1435 - Hydraulic systems.

Code of Federal Regulations, 2012 CFR

2012-01-01

... on the hydraulic system(s), and/or subsystem(s) and elements, except that analysis may be used in place of or to supplement testing, where the analysis is shown to be reliable and appropriate. All... system(s), subsystem(s), or element(s) must be subjected to performance, fatigue, and endurance tests...

History and Benefits of Engine Level Testing Throughout the Space Shuttle Main Engine Program

NASA Technical Reports Server (NTRS)

VanHooser, Katherine; Kan, Kenneth; Maddux, Lewis; Runkle, Everett

2010-01-01

Rocket engine testing is important throughout a program s life and is essential to the overall success of the program. Space Shuttle Main Engine (SSME) testing can be divided into three phases: development, certification, and operational. Development tests are conducted on the basic design and are used to develop safe start and shutdown transients and to demonstrate mainstage operation. This phase helps form the foundation of the program, demands navigation of a very steep learning curve, and yields results that shape the final engine design. Certification testing involves multiple engine samples and more aggressive test profiles that explore the boundaries of the engine to vehicle interface requirements. The hardware being tested may have evolved slightly from that in the development phase. Operational testing is conducted with mature hardware and includes acceptance testing of flight assets, resolving anomalies that occur in flight, continuing to expand the performance envelope, and implementing design upgrades. This paper will examine these phases of testing and their importance to the SSME program. Examples of tests conducted in each phase will also be presented.

Vortex shedding flow meter performance at high flow velocities

NASA Technical Reports Server (NTRS)

Siegwarth, J. D.

1986-01-01

In some of the ducts of the Space Shuttle Main Engine (SSME), the maximum liquid oxygen flow velocities approach 10 times those at which liquid flow measurements are normally made. The hydrogen gas flow velocities in other ducts exceed the maximum for gas flow measurement by more than a factor of 3. The results presented here show from water flow tests that vortex shedding flow meters of the appropriate design can measure water flow to velocities in excess of 55 m/s, which is a Reynolds number of about 2 million. Air flow tests have shown that the same meter can measure flow to a Reynolds number of at least 22 million. Vortex shedding meters were installed in two of the SSME ducts and tested with water flow. Narrow spectrum lines were obtained and the meter output frequencies were proportional to flow to + or - 0.5% or better over the test range with no flow conditioning, even though the ducts had multiple bends preceeding the meter location. Meters with the shedding elements only partially spanning the pipe and some meters with ring shaped shedding elements were also tested.

Implementation of a data management software system for SSME test history data

NASA Technical Reports Server (NTRS)

Abernethy, Kenneth

1986-01-01

The implementation of a software system for managing Space Shuttle Main Engine (SSME) test/flight historical data is presented. The software system uses the database management system RIM7 for primary data storage and routine data management, but includes several FORTRAN programs, described here, which provide customized access to the RIM7 database. The consolidation, modification, and transfer of data from the database THIST, to the RIM7 database THISRM is discussed. The RIM7 utility modules for generating some standard reports from THISRM and performing some routine updating and maintenance are briefly described. The FORTRAN accessing programs described include programs for initial loading of large data sets into the database, capturing data from files for database inclusion, and producing specialized statistical reports which cannot be provided by the RIM7 report generator utility. An expert system tutorial, constructed using the expert system shell product INSIGHT2, is described. Finally, a potential expert system, which would analyze data in the database, is outlined. This system could use INSIGHT2 as well and would take advantage of RIM7's compatibility with the microcomputer database system RBase 5000.

Analysis of internal flows relative to the space shuttle main engine

NASA Technical Reports Server (NTRS)

1987-01-01

Cooperative efforts between the Lockheed-Huntsville Computational Mechanics Group and the NASA-MSFC Computational Fluid Dynamics staff has resulted in improved capabilities for numerically simulating incompressible flows generic to the Space Shuttle Main Engine (SSME). A well established and documented CFD code was obtained, modified, and applied to laminar and turbulent flows of the type occurring in the SSME Hot Gas Manifold. The INS3D code was installed on the NASA-MSFC CRAY-XMP computer system and is currently being used by NASA engineers. Studies to perform a transient analysis of the FPB were conducted. The COBRA/TRAC code is recommended for simulating the transient flow of oxygen into the LOX manifold. Property data for modifying the code to represent LOX/GOX flow was collected. The ALFA code was developed and recommended for representing the transient combustion in the preburner. These two codes will couple through the transient boundary conditions to simulate the startup and/or shutdown of the fuel preburner. A study, NAS8-37461, is currently being conducted to implement this modeling effort.

Space Shuttle main engine OPAD: The search for a hardware enhanced plume

NASA Astrophysics Data System (ADS)

Powers, W. T.; Cooper, A. E.; Wallace, Tim L.; Buntine, W. L.; Whitaker, K. W.

1993-11-01

The process of applying spectroscopy to the Space Shuttle Main Engine (SSME) for plume diagnostics, as it exists today, originated at Marshall Space Flight Center in Huntsville, Alabama, and its implementation was assured largely through the efforts of Sverdrup AEDC, in Tullahoma, Tennessee. This team continues to lead and guide efforts in the plume diagnostics arena. The process, Optical Plume Anomaly Detection (OPAD), formed the basis for various activities in the development of ground-based systems as well as the development of in-flight plume spectroscopy. OPAD currently provides and will continue to provide valuable information relative to future systems definitions, instrumentation development, code validation, and data diagnostic processing. OPAD is based on the detection of anomalous atomic and molecular species in the SSME plume using two complete, stand-alone optical spectrometers. To-date OPAD has acquired data on 44 test firings of the SSME at the Technology Test Bed (TTB) at MSFC. The purpose of this paper will be to provide an introduction to the OPAD system by discussing the process of obtaining data as well as the methods of examining and interpreting the data. It will encompass such issues as selection of instrumentation correlation of data to nominal engine operation, investigation of SSME component erosion via OPAD spectral data, necessity and benefits of plume seeding, application of artificial intelligence (AI) techniques to data analysis, and the present status of efforts to quantify specie erosion utilizing standard plume and chemistry codes as well as radiative models currently under development.

Space Shuttle main engine OPAD: The search for a hardware enhanced plume

NASA Technical Reports Server (NTRS)

Powers, W. T.; Cooper, A. E.; Wallace, Tim L.; Buntine, W. L.; Whitaker, K. W.

1993-01-01

The process of applying spectroscopy to the Space Shuttle Main Engine (SSME) for plume diagnostics, as it exists today, originated at Marshall Space Flight Center in Huntsville, Alabama, and its implementation was assured largely through the efforts of Sverdrup AEDC, in Tullahoma, Tennessee. This team continues to lead and guide efforts in the plume diagnostics arena. The process, Optical Plume Anomaly Detection (OPAD), formed the basis for various activities in the development of ground-based systems as well as the development of in-flight plume spectroscopy. OPAD currently provides and will continue to provide valuable information relative to future systems definitions, instrumentation development, code validation, and data diagnostic processing. OPAD is based on the detection of anomalous atomic and molecular species in the SSME plume using two complete, stand-alone optical spectrometers. To-date OPAD has acquired data on 44 test firings of the SSME at the Technology Test Bed (TTB) at MSFC. The purpose of this paper will be to provide an introduction to the OPAD system by discussing the process of obtaining data as well as the methods of examining and interpreting the data. It will encompass such issues as selection of instrumentation correlation of data to nominal engine operation, investigation of SSME component erosion via OPAD spectral data, necessity and benefits of plume seeding, application of artificial intelligence (AI) techniques to data analysis, and the present status of efforts to quantify specie erosion utilizing standard plume and chemistry codes as well as radiative models currently under development.

Simulation verification techniques study. Subsystem simulation validation techniques

NASA Technical Reports Server (NTRS)

Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

1974-01-01

Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given.

Investigation of the feasibility of optical diagnostic measurements at the exit of the SSME

NASA Technical Reports Server (NTRS)

Shirley, John A.; Boedeker, Laurence R.

1993-01-01

Under Contract NAS8-36861 sponsored by NASA Marshall Space Flight Center, the United Technologies Research Center is conducting an investigation of the feasibility of remote optical diagnostics to measure temperature, species concentration and velocity at the exit of the Space Shuttle Main Engine (SSME). This is a two phase study consisting of a conceptual design phase followed by a laboratory experimental investigation. The first task of the conceptual design studies is to screen and evaluate the techniques which can be used for the measurements. The second task is to select the most promising technique or techniques, if as expected, more than one type of measurement must be used to measure all the flow variables of interest. The third task is to examine in detail analytically the capabilities and limitations of the selected technique(s). The results of this study are described in the section of this report entitled Conceptual Design Investigations. The conceptual design studies identified spontaneous Raman scattering and photodissociative flow-tagging for measurements respectively of gas temperature and major species concentration and for velocity. These techniques and others that were considered are described in the section describing the conceptual design. The objective of the second phase of investigations was to investigate experimentally the techniques identified in the first phase. The first task of the experimental feasibility study is to design and assemble laboratory scale experimental apparatus to evaluate the best approaches for SSME exit optical diagnostics for temperature, species concentrations and velocity, as selected in the Phase I conceptual design study. The second task is to evaluate performance, investigate limitations, and establish actual diagnostic capabilities, accuracies and precision for the selected optical systems. The third task is to evaluate design requirements and system trade-offs of conceptual instruments. Spontaneous Raman scattering excited by a KrF excimer laser pulse was investigated for SSME exit plane temperature and major species concentration measurements. The relative concentrations of molecular hydrogen and water vapor would be determined by measuring the integrated Q-branch scattering signals through narrow bandpass filters in front of photomultipliers. The temperature would be determined by comparing the signal from a single hydrogen rotational Raman line to the total hydrogen Q-branch signal. The rotational Raman line would be isolated by a monochromator and detected with a PMT.

Stepping-Motion Motor-Control Subsystem For Testing Bearings

NASA Technical Reports Server (NTRS)

Powers, Charles E.

1992-01-01

Control subsystem closed-loop angular-position-control system causing motor and bearing under test to undergo any of variety of continuous or stepping motions. Also used to test bearing-and-motor assemblies, motors, angular-position sensors including rotating shafts, and like. Monitoring subsystem gathers data used to evaluate performance of bearing or other article under test. Monitoring subsystem described in article, "Monitoring Subsystem For Testing Bearings" (GSC-13432).

Error Suppression for Hamiltonian-Based Quantum Computation Using Subsystem Codes

NASA Astrophysics Data System (ADS)

Marvian, Milad; Lidar, Daniel A.

2017-01-01

We present general conditions for quantum error suppression for Hamiltonian-based quantum computation using subsystem codes. This involves encoding the Hamiltonian performing the computation using an error detecting subsystem code and the addition of a penalty term that commutes with the encoded Hamiltonian. The scheme is general and includes the stabilizer formalism of both subspace and subsystem codes as special cases. We derive performance bounds and show that complete error suppression results in the large penalty limit. To illustrate the power of subsystem-based error suppression, we introduce fully two-local constructions for protection against local errors of the swap gate of adiabatic gate teleportation and the Ising chain in a transverse field.

Error Suppression for Hamiltonian-Based Quantum Computation Using Subsystem Codes.

PubMed

Marvian, Milad; Lidar, Daniel A

2017-01-20

We present general conditions for quantum error suppression for Hamiltonian-based quantum computation using subsystem codes. This involves encoding the Hamiltonian performing the computation using an error detecting subsystem code and the addition of a penalty term that commutes with the encoded Hamiltonian. The scheme is general and includes the stabilizer formalism of both subspace and subsystem codes as special cases. We derive performance bounds and show that complete error suppression results in the large penalty limit. To illustrate the power of subsystem-based error suppression, we introduce fully two-local constructions for protection against local errors of the swap gate of adiabatic gate teleportation and the Ising chain in a transverse field.

NFIRAOS in 2015: engineering for future integration of complex subsystems

NASA Astrophysics Data System (ADS)

Atwood, Jenny; Andersen, David; Byrnes, Peter; Densmore, Adam; Fitzsimmons, Joeleff; Herriot, Glen; Hill, Alexis

2016-07-01

The Narrow Field InfraRed Adaptive Optics System (NFIRAOS) will be the first-light facility Adaptive Optics (AO) system for the Thirty Meter Telescope (TMT). NFIRAOS will be able to host three science instruments that can take advantage of this high performance system. NRC Herzberg is leading the design effort for this critical TMT subsystem. As part of the final design phase of NFIRAOS, we have identified multiple subsystems to be sub-contracted to Canadian industry. The scope of work for each subcontract is guided by the NFIRAOS Work Breakdown Structure (WBS) and is divided into two phases: the completion of the final design and the fabrication, assembly and delivery of the final product. Integration of the subsystems at NRC will require a detailed understanding of the interfaces between the subsystems, and this work has begun by defining the interface physical characteristics, stability, local coordinate systems, and alignment features. In order to maintain our stringent performance requirements, the interface parameters for each subsystem are captured in multiple performance budgets, which allow a bottom-up error estimate. In this paper we discuss our approach for defining the interfaces in a consistent manner and present an example error budget that is influenced by multiple subsystems.

Ceramic composites for rocket engine turbines

NASA Technical Reports Server (NTRS)

Herbell, Thomas P.; Eckel, Andrew J.

1991-01-01

The use of ceramic materials in the hot section of the fuel turbopump of advanced reusable rocket engines promises increased performance and payload capability, improved component life and economics, and greater design flexibility. Severe thermal transients present during operation of the Space Shuttle Main Engine (SSME), push metallic components to the limit of their capabilities. Future engine requirements might be even more severe. In phase one of this two-phase program, performance benefits were quantified and continuous fiber reinforced ceramic matrix composite components demonstrated a potential to survive the hostile environment of an advanced rocket engine turbopump.

Ceramic composites for rocket engine turbines

NASA Technical Reports Server (NTRS)

Herbell, Thomas P.; Eckel, Andrew J.

1991-01-01

The use of ceramic materials in the hot section of the fuel turbopump of advanced reusable rocket engines promises increased performance and payload capability, improved component life and economics, and greater design flexibility. Severe thermal transients present during operation of the Space Shuttle Main Engine (SSME), push metallic components to the limit of their capabilities. Future engine requirements might be even more severe. In phase one of this two-phase program, performance benefits were quantified and continuous fiber reinforced ceramic matrix composite components demonstrated a potential to survive the hostile environment of an advaced rocket engine turbopump.

Return to flight SSME test at A2 test stand

NASA Image and Video Library

2004-07-16

The Space Shuttle Main Engine (SSME) reached a historic milestone July 16, 2004, when a successful flight acceptance test was conducted at NASA Stennis Space Center (SSC). The engine tested today is the first complete engine to be tested and shipped in its entirety to Kennedy Space Center for installation on Space Shuttle Discovery for STS-114, NASA's Return to Flight mission. The engine test, which began about 3:59 p.m. CDT, ran for 520 seconds (8 minutes), the length of time it takes for the Space Shuttle to reach orbit.

Overview of Aerothermodynamic Loads Definition Study

NASA Technical Reports Server (NTRS)

Povinelli, L. A.

1985-01-01

The Aerothermodynamic Loads Definition were studied to develop methods to more accurately predict the operating environment in the space shuttle main engine (SSME) components. Development of steady and time-dependent, three-dimensional viscous computer codes and experimental verification and engine diagnostic testing are considered. The steady, nonsteady, and transient operating loads are defined to accurately predict powerhead life. Improvements in the structural durability of the SSME turbine drive systems depends on the knowledge of the aerothermodynamic behavior of the flow through the preburner, turbine, turnaround duct, gas manifold, and injector post regions.

Structural dynamic analysis of the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Scott, L. P.; Jamison, G. T.; Mccutcheon, W. A.; Price, J. M.

1981-01-01

This structural dynamic analysis supports development of the SSME by evaluating components subjected to critical dynamic loads, identifying significant parameters, and evaluating solution methods. Engine operating parameters at both rated and full power levels are considered. Detailed structural dynamic analyses of operationally critical and life limited components support the assessment of engine design modifications and environmental changes. Engine system test results are utilized to verify analytic model simulations. The SSME main chamber injector assembly is an assembly of 600 injector elements which are called LOX posts. The overall LOX post analysis procedure is shown.

General view of the High Bay area of the Space ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the High Bay area of the Space Shuttle Main Engine (SSME) Processing Facility at Kennedy Space Center. This view shows the specially modified fork lift used for horizontal installation and removal of the SSMEs into and out of the Orbiters. SSME number 2059 is in the background and is in the process of being scanned with a high-definition laser scanner to acquire field documentation for the production of historic documentatin. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Flow induced vibrations in the SSME injector heads

NASA Technical Reports Server (NTRS)

Lepore, Frank A.

1991-01-01

A description is given of the flowfield in the Space Shuttle Main Engine (SSME) powerhead, the mechanisms which control flow-induced vibrations, and previous experimental work. An in-depth description is given of the development phase of the program , which includes the analysis, design, and fabrication of liquid oxygen (LOX) posts models used in the experimental phase, as well as test facilities, equipment, and procedures used. Also covered is the experimental data analysis, which includes overall steady state powerhead flowfield as well as the high frequency response of the LOX posts.

Integrated flight/propulsion control - Subsystem specifications for performance

NASA Technical Reports Server (NTRS)

Neighbors, W. K.; Rock, Stephen M.

1993-01-01

A procedure is presented for calculating multiple subsystem specifications given a number of performance requirements on the integrated system. This procedure applies to problems where the control design must be performed in a partitioned manner. It is based on a structured singular value analysis, and generates specifications as magnitude bounds on subsystem uncertainties. The performance requirements should be provided in the form of bounds on transfer functions of the integrated system. This form allows the expression of model following, command tracking, and disturbance rejection requirements. The procedure is demonstrated on a STOVL aircraft design.

Integrated flight/propulsion control system design based on a decentralized, hierarchical approach

NASA Technical Reports Server (NTRS)

Mattern, Duane; Garg, Sanjay; Bullard, Randy

1989-01-01

A sample integrated flight/propulsion control system design is presented for the piloted longitudinal landing task with a modern, statistically unstable fighter aircraft. The design procedure is summarized. The vehicle model used in the sample study is described, and the procedure for partitioning the integrated system is presented along with a description of the subsystems. The high-level airframe performance specifications and control design are presented and the control performance is evaluated. The generation of the low-level (engine) subsystem specifications from the airframe requirements are discussed, and the engine performance specifications are presented along with the subsystem control design. A compensator to accommodate the influence of airframe outputs on the engine subsystem is also considered. Finally, the entire closed loop system performance and stability characteristics are examined.

Integrated flight/propulsion control system design based on a decentralized, hierarchical approach

NASA Technical Reports Server (NTRS)

Mattern, Duane; Garg, Sanjay; Bullard, Randy

1989-01-01

A sample integrated flight/propulsion control system design is presented for the piloted longitiudinal landing task with a modern, statistically unstable fighter aircraft. The design procedure is summarized, the vehicle model used in the sample study is described, and the procedure for partitioning the integrated system is presented along with a description of the subsystems. The high-level airframe performance specifications and control design are presented and the control performance is evaluated. The generation of the low-level (engine) subsystem specifications from the airframe requirements are discussed, and the engine performance specifications are presented along with the subsystem control design. A compensator to accommodate the influence of airframe outputs on the engine subsystem is also considered. Finally, the entire closed loop system performance and stability characteristics are examined.

PC-402 Pioneer Venus orbiter spacecraft mission operational characteristics document

NASA Technical Reports Server (NTRS)

Barker, F. C.; Butterworth, L. W.; Daniel, R. E.; Drean, R. J.; Filetti, K. A.; Fisher, J. N.; Nowak, L. A.; Porzucki, J.; Salvatore, J. O.; Tadler, G. A.

1978-01-01

The operational characteristics of the Orbiter spacecraft and its subsystems are described. In extensive detail. Description of the nominal phases, system interfaces, and the capabilities and limitations of system level performance are included along with functional and operational descriptions at the subsystem and unit level the subtleties of nominal operation as well as detailed capabilities and limitations beyond nominal performance are discussed. A command and telemetry logic flow diagram for each subsystem is included. Each diagram encountered along each command signal path into, and each telemetry signal path out of the subsystem. Normal operating modes that correspond to the performance of specific functions at the time of specific events in the mission are also discussed. Principal backup means of performing the normal Orbiter operating modes are included.

STS-59 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1994-01-01

The STS-59 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the sixty-second flight of the Space Shuttle Program and sixth flight of the Orbiter vehicle Endeavor (OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET designated as ET-63; three SSME's which were designated as serial numbers 2028, 2033, and 2018 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-065. The RSRM's that were installed in each SRB were designated as 360W037A (welterweight) for the left SRB, and 360H037B (heavyweight) for the right SRB. This STS-59 Space Shuttle Program Mission Report fulfills the Space Shuttle Program requirement as documented in NSTS 07700, Volume 8, Appendix E. That document requires that each major organizational element supporting the Program report the results of its hardware evaluation and mission performance plus identify all related in-flight anomalies. The primary objective of the STS-59 mission was to successfully perform the operations of the Space Radar Laboratory-1 (SRL-1). The secondary objectives of this flight were to perform the operations of the Space Tissue Loss-A (STL-A) and STL-B payloads, the Visual Function Tester-4 (VFT-4) payload, the Shuttle Amateur Radio Experiment-2 (SAREX-2) experiment, the Consortium for Materials Development in Space Complex Autonomous Payload-4 (CONCAP-4), and the three Get-Away Special (GAS) payloads.

A comparative study of multivariable robustness analysis methods as applied to integrated flight and propulsion control

NASA Technical Reports Server (NTRS)

Schierman, John D.; Lovell, T. A.; Schmidt, David K.

1993-01-01

Three multivariable robustness analysis methods are compared and contrasted. The focus of the analysis is on system stability and performance robustness to uncertainty in the coupling dynamics between two interacting subsystems. Of particular interest is interacting airframe and engine subsystems, and an example airframe/engine vehicle configuration is utilized in the demonstration of these approaches. The singular value (SV) and structured singular value (SSV) analysis methods are compared to a method especially well suited for analysis of robustness to uncertainties in subsystem interactions. This approach is referred to here as the interacting subsystem (IS) analysis method. This method has been used previously to analyze airframe/engine systems, emphasizing the study of stability robustness. However, performance robustness is also investigated here, and a new measure of allowable uncertainty for acceptable performance robustness is introduced. The IS methodology does not require plant uncertainty models to measure the robustness of the system, and is shown to yield valuable information regarding the effects of subsystem interactions. In contrast, the SV and SSV methods allow for the evaluation of the robustness of the system to particular models of uncertainty, and do not directly indicate how the airframe (engine) subsystem interacts with the engine (airframe) subsystem.

Computer-Aided Air-Traffic Control In The Terminal Area

NASA Technical Reports Server (NTRS)

Erzberger, Heinz

1995-01-01

Developmental computer-aided system for automated management and control of arrival traffic at large airport includes three integrated subsystems. One subsystem, called Traffic Management Advisor, another subsystem, called Descent Advisor, and third subsystem, called Final Approach Spacing Tool. Data base that includes current wind measurements and mathematical models of performances of types of aircraft contributes to effective operation of system.

Orbiter Atlantis (STS-110) Launch With New Block II Engines

NASA Technical Reports Server (NTRS)

2002-01-01

Powered by three newly-enhanced Space Shuttle Maine Engines (SSMEs), called the Block II Maine Engines, the Space Shuttle Orbiter Atlantis lifted off from the Kennedy Space Center launch pad on April 8, 2002 for the STS-110 mission. The Block II Main Engines incorporate an improved fuel pump featuring fewer welds, a stronger integral shaft/disk, and more robust bearings, making them safer and more reliable, and potentially increasing the number of flights between major overhauls. NASA continues to increase the reliability and safety of Shuttle flights through a series of enhancements to the SSME. The engines were modified in 1988 and 1995. Developed in the 1970s and managed by the Space Shuttle Projects Office at the Marshall Space Flight Center, the SSME is the world's most sophisticated reusable rocket engine. The new turbopump made by Pratt and Whitney of West Palm Beach, Florida, was tested at NASA's Stennis Space Center in Mississippi. Boeing Rocketdyne in Canoga Park, California, manufactures the SSME. This image was extracted from engineering motion picture footage taken by a tracking camera.

Assessment of the operating characteristics of the SSME LOX turbopump pump-end bearing

NASA Technical Reports Server (NTRS)

New, L. S.; Tiller, B. K.

1984-01-01

A bearing/shaft model of the SSME LOX turbopump was developed using the SHABERTH bearing/shaft math modeling computer code. A previously developed bearing/shaft thermal model of the SSME LOX turbopump turbine and bearing was used in conjunction with SHABERTH to evaluate the thermomechanical operating characteristics of the LOX turbopump end bearings. Results show that for the two unmounted diametrical clearances evaluated (4.0 mils and 6.3 mils), the inboard pump end bearing supports about 81% of the isolator load for the small clearance and 77% of the isolator load for the larger clearance. Bearing clearance changes due to thermal effects were 40% for the 4.0 mil diametrical clearance case and 19% for the 6.3 mil clearance case evaluated. The thermal analysis included evaluation of bearing temperatures for a subcooled case and a saturated case. Results indicate that no drastic temperature change occurred between the two cases. Since the rolling element and race surfaces of the subcooled case were at temperatures sufficiently high enough to be vapor blanketed, exceeding saturation temperature at the bearing inlet did not increase surface temperatures greatly.

Closeup view of the aft fuselage of the Orbiter Discovery ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Close-up view of the aft fuselage of the Orbiter Discovery looking at the thrust structure that supports the Space Shuttle Main Engines (SSMEs). In this view, SSME number two position is on the left and SSME number three position is on the right. The thrust structure transfers the forces produce by the engines into and through the airframe of the orbiter. The thrust structure includes the SSMEs load reaction truss structure, engine interface fittings and the hydraulic-actuator support structure. The propellant feed lines are the plugged and capped orifices within the engine bays. Note that SSME position two is rotated ninety degrees from position three and one. This was needed to enable enough clearance for the engines to fit and gimbal. Note in engine bay three is a clear view of the actuators that control the gambling of that engine. This view was taken from a service platform in the Orbiter Processing Facility at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Fiber reinforced superalloys for rocket engines

NASA Technical Reports Server (NTRS)

Petrasek, Donald W.; Stephens, Joseph R.

1989-01-01

High pressure turbopumps for advanced reusable liquid propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several fold increase in life and over a 200 C increase in temperature capability over the current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

The effects of skeletal separation and moisture enhancement for improving the eating quality of cull cow beef.

PubMed

Streiter, P J; Campbell, C P; Mandell, I B

2012-12-01

Sixty-two cull beef cows were slaughtered to investigate effects of skeletal separation and moisture enhancement on beef eating quality. Muscles from each carcass side were randomly assigned to 1) no postmortem processing (NPP), 2) prerigor skeletal separation (SS), 3) moisture enhancement (ME) using calcium ascorbate or 4) a combination of SS and ME (SS/ME). Postmortem processing treatment (PPT) by ageing (PM) interactions (P<0.01) for shear force were present for longissimus. As PM ageing increased from 7 to 21 d, there was a greater decrease (P<0.05) in shear force with NPP vs. all other PPT. Trained taste panellists found SS, ME and SS/ME improved (P<0.05) palatability attributes vs. NPP. An additive effect of combining SS and ME improved palatability traits versus SS or ME alone. Panellists found no differences (P>0.14) in softness and tenderness between SS/ME and Canadian AA or AAA beef. Postmortem processing of beef cows may produce beef as tender and juicy as beef from younger carcasses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fiber reinforced superalloys for rocket engines

NASA Technical Reports Server (NTRS)

Petrasek, Donald W.; Stephens, Joseph R.

1988-01-01

High-pressure turbopumps for advanced reusable liquid-propellant rocket engines such as that for the Space Shuttle Main Engine (SSME) require turbine blade materials that operate under extreme conditions of temperature, hydrogen environment, high-cycle fatigue loading, thermal fatigue and thermal shock. Such requirements tax the capabilities of current blade materials. Based on projections of properties for tungsten fiber reinforced superalloy (FRS) composites, it was concluded that FRS turbine blades offer the potential of a several-fold increase in life and over a 200C increase in temperature capability over current SSME blade material. FRS composites were evaluated with respect to mechanical property requirements for SSME blade applications. Compared to the current blade material, the thermal shock resistance of FRS materials is excellent, two to nine times better, and their thermal fatigue resistance is equal to or higher than the current blade material. FRS materials had excellent low and high-cycle fatigue strengths, and thermal shock-induced surface microcracks had no influence on their fatigue strength. The material also exhibited negligible embrittlement when exposed to a hydrogen environment.

Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 5: Supporting Analyses and Trade Studies. [development and testing of a solar thermal power plant

NASA Technical Reports Server (NTRS)

Holl, R. J.

1979-01-01

The development and design of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. Thermal and stress analyses are performed on the collector subsystem, energy storage subsystem, energy transport subsystem, the power conversion subsystem, and the plant control subsystem.

Advanced vehicle systems assessment. Volume 2: Subsystems assessment

NASA Technical Reports Server (NTRS)

Hardy, K.

1985-01-01

Volume 2 (Subsystems Assessment) is part of a five-volume report entitled Advanced Vehicle Systems Assessment. Volume 2 presents the projected performance capabilities and cost characteristics of applicable subsystems, considering an additional decade of development. Subsystems of interest include energy storage and conversion devices as well as the necessary powertrain components and vehicle subsystems. Volume 2 also includes updated battery information based on the assessment of an independent battery review board (with the aid of subcontractor reports on advanced battery characteristics).

Performance/Design Requirements and Detailed Technical Description for a Computer-Directed Training Subsystem for Integration into the Air Force Phase II Base Level System.

ERIC Educational Resources Information Center

Butler, A. K.; And Others

The performance/design requirements and a detailed technical description for a Computer-Directed Training Subsystem to be integrated into the Air Force Phase II Base Level System are described. The subsystem may be used for computer-assisted lesson construction and has presentation capability for on-the-job training for data automation, staff, and…

System design of the Pioneer Venus spacecraft. Volume 10: Propulsion/orbit insertion subsystem studies

NASA Technical Reports Server (NTRS)

Rosenstein, B. J.

1973-01-01

The Pioneer Venus orbiter and multiprobe missions require spacecraft maneuvers for successful accomplishment. This report presents the results of studies performed to define the propulsion subsystems required to perform those maneuvers. Primary goals were to define low mass subsystems capable of performing the required missions with a high degree of reliability for low cost. A review was performed of all applicable propellants and thruster types, as well as propellant management techniques. Based on this review, a liquid monopropellant hydrazine propulsion subsystem was selected for all multiprobe mission maneuvers, and for all orbiter mission maneuvers except orbit insertion. A pressure blowdown operating mode was selected using helium as the pressurizing gas. The forces associated with spacecraft rotations were used to control the liquid-gas interface and resulting propellant orientation within the tank.

A membrane-based subsystem for very high recoveries of spacecraft waste waters

NASA Technical Reports Server (NTRS)

Ray, Roderick J.; Retzlaff, Sandra E.; Radke-Mitchell, Lyn; Newbold, David D.; Price, Donald F.

1986-01-01

This paper describes the continued development of a membrane-based subsystem designed to recover up to 99.5 percent of the water from various spacecraft waste waters. Specifically discussed are: (1) the design and fabrication of an energy-efficient reverse-osmosis (RO) breadboard subsystem; (2) data showing the performance of this subsystem when operated on a synthetic wash-water solution - including the results of a 92-day test; and (3) the results of pasteurization studies, including the design and operation of an in-line pasteurizer. Also included in this paper is a discussion of the design and performance of a second RO stage. This second stage results in higher-purity product water at a minimal energy requirement and provides a substantial redundancy factor to this subsystem.

Research pressure instrumentation for NASA Space Shuttle main engine

NASA Technical Reports Server (NTRS)

Anderson, P. J.; Nussbaum, P.; Gustafson, G.

1984-01-01

The development of prototype pressure transducers which are targeted to meet the Space Shuttle Main Engine SSME performance design goals is discussed. The fabrication, testing and delivery of 10 prototype units is examined. Silicon piezoresistive strain sensing technology is used to achieve the objectives of advanced state-of-the-art pressure sensors in terms of reliability, accuracy and ease of manufacture. Integration of multiple functions on a single chip is the key attribute of this technology.

Fuel-efficient cruise performance model for general aviation piston engine airplanes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parkinson, R.C.H.

1982-01-01

The uses and limitations of typical Pilot Operating Handbook cruise performance data, for constructing cruise performance models suitable for maximizing specific range, are first examined. These data are found to be inadequate for constructing such models. A new model of General Aviation piston-prop airplane cruise performance is then developed. This model consists of two subsystem models: the airframe-propeller-atmosphere subsystem model; and the engine-atmosphere subsystem model. The new model facilitates maximizing specific range; and by virtue of its simplicity and low volume data storage requirements, appears suitable for airborne microprocessor implementation.

Development of Life Prediction Capabilities for Liquid Propellant Rocket Engines. Task 4. Post-Fire Diagnostic System for the SSME System Architecture Study.

DTIC Science & Technology

1991-07-31

90 START MCC LN CAV PR 3 UNDERSHOOT ABOVE THRESHOLD YES MI A2-492 2/13/90 MAINSTAGE HPOT DS TMP CHANNEL A/B DIVERGENCE NO MI A2-492 2/13/90 MAINSTAGE ...System for the SSME System Architecture Study Y, , Contract NAS 3 -25883 JUL 31󈧣 CR-187112 Prepared for: National Aeronautics and Space...Liquid Propellant Rocket Engines Contract No. NAS 3 -25883 Eli Ki ,,, July 31, 1991 BY Dist Prepared By.: Mr. Mark Gage Aerojet Propulsion Division Box

Structural Integrity and Durability of Reusable Space Propulsion Systems

NASA Technical Reports Server (NTRS)

1991-01-01

A two-day conference on the structural integrity and durability of reusable space propulsion systems was held on 14 to 15 May 1991 at the NASA Lewis Research Center. Presentations were made by industry, university, and government researchers organized into four sessions: (1) aerothermodynamic loads; (2) instrumentation; (3) fatigue, fracture, and constitutive modeling; and (4) structural dynamics. The principle objectives were to disseminate research results and future plans in each of four areas. This publication contains extended abstracts and the visual material presented during the conference. Particular emphasis is placed on the Space Shuttle Main Engine (SSME) and the SSME turbopump.

Duct flow nonuniformities: Effect of struts in SSME HGM 2+

NASA Technical Reports Server (NTRS)

Burke, Roger

1988-01-01

This study consists of an analysis of flow through the Space Shuttle Main Engine (SSME) Hot Gas Manifold (HGM) for the purpose of understanding and quantifying the flow environment and, in particular, the flow through a region of structural supports located between the inner and outer walls of the HGM. The primary task of the study, as defined by NASA-MSFC, is to assess and develop the computational capability for analyzing detailed three-dimensional flow through the HGM support strut region to be incorporated into a full fuelside HGM analysis. Secondarily, computed results are to be compared with available experimental results.

Evaluation of shuttle turbopump bearings

NASA Technical Reports Server (NTRS)

Dufrane, K. F.; Kannel, J. W.

1978-01-01

Because the high pressure turbopumps used on the space shuttle main engine (SSME) are high speed machines and rotor dynamics analysis of these units is very complicated, it was considered necessary to verify calculated turbomachinery shaft bearing loads by analysis of ball bearing load tracks. This report presents the methods used and the results of load track analysis on one set of bearings removed from a high pressure liquid oxygen turbopump which had been subjected to SSME static firing tests. This type of analysis was found useful in determining bearing operating conditions and for verifying rotor dynamics computer models.

KSC-95PC585

NASA Image and Video Library

1995-04-17

KENNEDY SPACE CENTER, FLA. - A Space Shuttle Main Engine (SSME) hoist prepares to lift the first Block 1 engine to be installed in an orbiter into the number one position on Discovery while the spaceplane is being prepared for the STS-70 mission in the high bay of Orbiter Processing Facility 2. The new engine, SSME No. 2036, features a new high-pressure liquid oxygen turbopump, a two-duct powerhead, a baffleless main injector, a single-coil heat exchanger and start sequence modifications. The other two main engines to be used during the liftoff of the STS-70 mission are of the existing Phase II design.

Space Shuttle Main Engine Public Test Firing

NASA Image and Video Library

2000-07-25

A new NASA Space Shuttle Main Engine (SSME) roars to the approval of more than 2,000 people who came to John C. Stennis Space Center in Hancock County, Miss., on July 25 for a flight-certification test of the SSME Block II configuration. The engine, a new and significantly upgraded shuttle engine, was delivered to NASA's Kennedy Space Center in Florida for use on future shuttle missions. Spectators were able to experience the 'shake, rattle and roar' of the engine, which ran for 520 seconds - the length of time it takes a shuttle to reach orbit.

Space shuttle main engine fault detection using neural networks

NASA Technical Reports Server (NTRS)

Bishop, Thomas; Greenwood, Dan; Shew, Kenneth; Stevenson, Fareed

1991-01-01

A method for on-line Space Shuttle Main Engine (SSME) anomaly detection and fault typing using a feedback neural network is described. The method involves the computation of features representing time-variance of SSME sensor parameters, using historical test case data. The network is trained, using backpropagation, to recognize a set of fault cases. The network is then able to diagnose new fault cases correctly. An essential element of the training technique is the inclusion of randomly generated data along with the real data, in order to span the entire input space of potential non-nominal data.

Calculations of combustion response profiles and oscillations

NASA Technical Reports Server (NTRS)

Priem, Richard J.; Breisacher, Kevin J.

1993-01-01

The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Pressure and velocity oscillations calculated using this procedure are presented for the Space Shuttle Main Engine (SSME) to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Results of calculations to determine local combustion responses using detailed physical models for injection, atomization, and vaporization with gas phase oscillations in baffled and unbaffled SSME combustors are presented. The contributions of the various physical phenomena occurring in a combustor to oscillations in combustion response were determined.

Real-time failure control (SAFD)

NASA Technical Reports Server (NTRS)

Panossian, Hagop V.; Kemp, Victoria R.; Eckerling, Sherry J.

1990-01-01

The Real Time Failure Control program involves development of a failure detection algorithm, referred as System for Failure and Anomaly Detection (SAFD), for the Space Shuttle Main Engine (SSME). This failure detection approach is signal-based and it entails monitoring SSME measurement signals based on predetermined and computed mean values and standard deviations. Twenty four engine measurements are included in the algorithm and provisions are made to add more parameters if needed. Six major sections of research are presented: (1) SAFD algorithm development; (2) SAFD simulations; (3) Digital Transient Model failure simulation; (4) closed-loop simulation; (5) SAFD current limitations; and (6) enhancements planned for.

Thin-film sensors for reusable space propulsion systems

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Kim, Walter S.

1989-01-01

Thin-film thermocouples (TFTCs) were developed for aircraft gas turbine engines and are in use for temperature measurement on turbine blades up to 1800 F. Established aircraft engine gas turbine technology is currently being adapted to turbine engine blade materials and the environment encountered in the Space Shuttle Main Engine (SSME)-severe thermal shock from cryogenic fuel to combustion temperatures. Initial results with coupons of MAR M-246 (+Hf) and PWA 1480 were followed by fabrication of TFTC on SSME turbine blades. Current efforts are focused on preparation for testing in the Turbine Blade Tester at NASA Marshall Space Flight Center.

Iterative procedures for space shuttle main engine performance models

NASA Technical Reports Server (NTRS)

Santi, L. Michael

1989-01-01

Performance models of the Space Shuttle Main Engine (SSME) contain iterative strategies for determining approximate solutions to nonlinear equations reflecting fundamental mass, energy, and pressure balances within engine flow systems. Both univariate and multivariate Newton-Raphson algorithms are employed in the current version of the engine Test Information Program (TIP). Computational efficiency and reliability of these procedures is examined. A modified trust region form of the multivariate Newton-Raphson method is implemented and shown to be superior for off nominal engine performance predictions. A heuristic form of Broyden's Rank One method is also tested and favorable results based on this algorithm are presented.

Analysis of link performance for the FOENEX laser communications system

NASA Astrophysics Data System (ADS)

Juarez, Juan C.; Young, David W.; Venkat, Radha A.; Brown, David M.; Brown, Andrea M.; Oberc, Rachel L.; Sluz, Joseph E.; Pike, H. Alan; Stotts, Larry B.

2012-06-01

A series of experiments were conducted to validate the performance of the free-space optical communications (FSOC) subsystem under DARPA's FOENEX program. Over six days, bidirectional links at ranges of 10 and 17 km were characterized during different periods of the day to evaluate link performance. This paper will present the test configuration, evaluate performance of the FSOC subsystem against a variety of characterization approaches, and discuss the impact of the results, particularly with regards to the optical terminals. Finally, this paper will summarize the impact of turbulence conditions on the FSOC subsystem and present methods for estimating performance under different link distances and turbulence conditions.

Apollo experience report: Lunar module electrical power subsystem

NASA Technical Reports Server (NTRS)

Campos, A. B.

1972-01-01

The design and development of the electrical power subsystem for the lunar module are discussed. The initial requirements, the concepts used to design the subsystem, and the testing program are explained. Specific problems and the modifications or compromises (or both) imposed for resolution are detailed. The flight performance of the subsystem is described, and recommendations pertaining to power specifications for future space applications are made.

A hierarchically distributed architecture for fault isolation expert systems on the space station

NASA Technical Reports Server (NTRS)

Miksell, Steve; Coffer, Sue

1987-01-01

The Space Station Axiomatic Fault Isolating Expert Systems (SAFTIES) system deals with the hierarchical distribution of control and knowledge among independent expert systems doing fault isolation and scheduling of Space Station subsystems. On its lower level, fault isolation is performed on individual subsystems. These fault isolation expert systems contain knowledge about the performance requirements of their particular subsystem and corrective procedures which may be involved in repsonse to certain performance errors. They can control the functions of equipment in their system and coordinate system task schedules. On a higher level, the Executive contains knowledge of all resources, task schedules for all systems, and the relative priority of all resources and tasks. The executive can override any subsystem task schedule in order to resolve use conflicts or resolve errors that require resources from multiple subsystems. Interprocessor communication is implemented using the SAFTIES Communications Interface (SCI). The SCI is an application layer protocol which supports the SAFTIES distributed multi-level architecture.

Electrochemical energy storage subsystems study, volume 1

NASA Technical Reports Server (NTRS)

Miller, F. Q.; Richardson, P. W.; Graff, C. L.; Jordan, M. V.; Patterson, V. L.

1981-01-01

The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models define baseline designs and costs. The major design and performance parameters are each varied to determine their influence on LCC around the baseline values.

Electrochemical Energy Storage Subsystems Study, Volume 2

NASA Technical Reports Server (NTRS)

Miller, F. Q.; Richardson, P. W.; Graff, C. L.; Jordan, M. V.; Patterson, V. L.

1981-01-01

The effects on life cycle costs (LCC) of major design and performance technology parameters for multi kW LEO and GEO energy storage subsystems using NiCd and NiH2 batteries and fuel cell/electrolysis cell devices were examined. Design, performance and LCC dynamic models are developed based on mission and system/subsystem requirements and existing or derived physical and cost data relationships. The models are exercised to define baseline designs and costs. Then the major design and performance parameters are each varied to determine their influence on LCC around the baseline values.

Small spacecraft power and thermal subsystems

NASA Technical Reports Server (NTRS)

Eakman, D.; Lambeck, R.; Mackowski, M.; Slifer, L., Jr.

1994-01-01

This white paper provides a general guide to the conceptual design of satellite power and thermal control subsystems with special emphasis on the unique design aspects associated with small satellites. The operating principles of these technologies are explained and performance characteristics of current and projected components are provided. A tutorial is presented on the design process for both power and thermal subsystems, with emphasis on unique issues relevant to small satellites. The ability of existing technology to meet future performance requirements is discussed. Conclusions and observations are presented that stress cost-effective, high-performance design solutions.

PC-403: Pioneer Venus multiprobe spacecraft mission operational characteristics document, volume 1

NASA Technical Reports Server (NTRS)

Barker, F. C.

1978-01-01

The operational characteristics of the multiprobe system and its subsystem are described. System level, description of the nominal phases, system interfaces, and the capabilities and limitations of system level performance are presented. Bus spacecraft functional and operational descriptions at the subsystem and unit level are presented. The subtleties of nominal operation as well as detailed capabilities and limitations beyond nominal performance are discussed. A command and telemetry logic flow diagram for each subsystem is included. Each diagram identifies in symbolic logic all signal conditioning encountered along each command signal path into, and each telemetry signal path out of the subsystem.

Non-intrusive speed sensor. [space shuttle main engine turbopumps

NASA Technical Reports Server (NTRS)

Maram, J.; Wyett, L.

1984-01-01

A computerized literature search was performed to identify candidate technologies for remote, non-intrusive speed sensing applications in Space Shuttle Main Engine (SSME) turbopumps. The three most promising technologies were subjected to experimental evaluation to quantify their performance characteristics under the harsh environmental requirements within the turbopumps. Although the infrared and microwave approaches demonstrated excellent cavitation immunity in laboratory tests, the variable-source magnetic speed sensor emerged as the most viable approach. Preliminary design of this speed sensor encountered no technical obstacles and resulted in viable and feasible speed nut, sensor housing, and sensor coil designs.

Thermal finite-element analysis of space shuttle main engine turbine blade

NASA Technical Reports Server (NTRS)

Abdul-Aziz, Ali; Tong, Michael T.; Kaufman, Albert

1987-01-01

Finite-element, transient heat transfer analyses were performed for the first-stage blades of the space shuttle main engine (SSME) high-pressure fuel turbopump. The analyses were based on test engine data provided by Rocketdyne. Heat transfer coefficients were predicted by performing a boundary-layer analysis at steady-state conditions with the STAN5 boundary-layer code. Two different peak-temperature overshoots were evaluated for the startup transient. Cutoff transient conditions were also analyzed. A reduced gas temperature profile based on actual thermocouple data was also considered. Transient heat transfer analyses were conducted with the MARC finite-element computer code.

A parametric sensitivity study for single-stage-to-orbit hypersonic vehicles using trajectory optimization

NASA Astrophysics Data System (ADS)

Lovell, T. Alan; Schmidt, D. K.

1994-03-01

The class of hypersonic vehicle configurations with single stage-to-orbit (SSTO) capability reflect highly integrated airframe and propulsion systems. These designs are also known to exhibit a large degree of interaction between the airframe and engine dynamics. Consequently, even simplified hypersonic models are characterized by tightly coupled nonlinear equations of motion. In addition, hypersonic SSTO vehicles present a major system design challenge; the vehicle's overall mission performance is a function of its subsystem efficiencies including structural, aerodynamic, propulsive, and operational. Further, all subsystem efficiencies are interrelated, hence, independent optimization of the subsystems is not likely to lead to an optimum design. Thus, it is desired to know the effect of various subsystem efficiencies on overall mission performance. For the purposes of this analysis, mission performance will be measured in terms of the payload weight inserted into orbit. In this report, a trajectory optimization problem is formulated for a generic hypersonic lifting body for a specified orbit-injection mission. A solution method is outlined, and results are detailed for the generic vehicle, referred to as the baseline model. After evaluating the performance of the baseline model, a sensitivity study is presented to determine the effect of various subsystem efficiencies on mission performance. This consists of performing a parametric analysis of the basic design parameters, generating a matrix of configurations, and determining the mission performance of each configuration. Also, the performance loss due to constraining the total head load experienced by the vehicle is evaluated. The key results from this analysis include the formulation of the sizing problem for this vehicle class using trajectory optimization, characteristics of the optimal trajectories, and the subsystem design sensitivities.

A parametric sensitivity study for single-stage-to-orbit hypersonic vehicles using trajectory optimization

NASA Technical Reports Server (NTRS)

Lovell, T. Alan; Schmidt, D. K.

1994-01-01

The class of hypersonic vehicle configurations with single stage-to-orbit (SSTO) capability reflect highly integrated airframe and propulsion systems. These designs are also known to exhibit a large degree of interaction between the airframe and engine dynamics. Consequently, even simplified hypersonic models are characterized by tightly coupled nonlinear equations of motion. In addition, hypersonic SSTO vehicles present a major system design challenge; the vehicle's overall mission performance is a function of its subsystem efficiencies including structural, aerodynamic, propulsive, and operational. Further, all subsystem efficiencies are interrelated, hence, independent optimization of the subsystems is not likely to lead to an optimum design. Thus, it is desired to know the effect of various subsystem efficiencies on overall mission performance. For the purposes of this analysis, mission performance will be measured in terms of the payload weight inserted into orbit. In this report, a trajectory optimization problem is formulated for a generic hypersonic lifting body for a specified orbit-injection mission. A solution method is outlined, and results are detailed for the generic vehicle, referred to as the baseline model. After evaluating the performance of the baseline model, a sensitivity study is presented to determine the effect of various subsystem efficiencies on mission performance. This consists of performing a parametric analysis of the basic design parameters, generating a matrix of configurations, and determining the mission performance of each configuration. Also, the performance loss due to constraining the total head load experienced by the vehicle is evaluated. The key results from this analysis include the formulation of the sizing problem for this vehicle class using trajectory optimization, characteristics of the optimal trajectories, and the subsystem design sensitivities.

An Investigation of State-Space Model Fidelity for SSME Data

NASA Technical Reports Server (NTRS)

Martin, Rodney Alexander

2008-01-01

In previous studies, a variety of unsupervised anomaly detection techniques for anomaly detection were applied to SSME (Space Shuttle Main Engine) data. The observed results indicated that the identification of certain anomalies were specific to the algorithmic method under consideration. This is the reason why one of the follow-on goals of these previous investigations was to build an architecture to support the best capabilities of all algorithms. We appeal to that goal here by investigating a cascade, serial architecture for the best performing and most suitable candidates from previous studies. As a precursor to a formal ROC (Receiver Operating Characteristic) curve analysis for validation of resulting anomaly detection algorithms, our primary focus here is to investigate the model fidelity as measured by variants of the AIC (Akaike Information Criterion) for state-space based models. We show that placing constraints on a state-space model during or after the training of the model introduces a modest level of suboptimality. Furthermore, we compare the fidelity of all candidate models including those embodying the cascade, serial architecture. We make recommendations on the most suitable candidates for application to subsequent anomaly detection studies as measured by AIC-based criteria.

LANDSAT-1 and LANDSAT-2 flight evaluation report, 23 April - 23 July 1976

NASA Technical Reports Server (NTRS)

1976-01-01

LANDSAT 1 and 2 operations were described, giving detailed charts and tables of their performances since 1972. Orbital parameters, attitude control subsystem, telemetry subsystem, orbit adjust subsystem, and magnetic moment compensating assembly were some of the main parameters discussed.

Evaluating Performances of Solar-Energy Systems

NASA Technical Reports Server (NTRS)

Jaffe, L. D.

1987-01-01

CONC11 computer program calculates performances of dish-type solar thermal collectors and power systems. Solar thermal power system consists of one or more collectors, power-conversion subsystems, and powerprocessing subsystems. CONC11 intended to aid system designer in comparing performance of various design alternatives. Written in Athena FORTRAN and Assembler.

Development and in-flight performance of the Mariner 9 spacecraft propulsion system

NASA Technical Reports Server (NTRS)

Evans, D. D.; Cannova, R. D.; Cork, M. J.

1972-01-01

On November 14, 1971, Mariner 9 was decelerated into orbit about Mars by a 1334-newton (300-lbf) liquid bipropellant propulsion system. The development and in-flight performance are described and summarized of this pressure-fed, nitrogen tetroxide/monomethyl hydrazine bipropellant system. The design of all Mariner propulsion subsystems has been predicated upon the premise that simplicity of approach, coupled with thorough qualification and margin-limits testing, is the key to cost-effective reliability. The qualification test program and analytical modeling of the Mariner 9 subsystem are discussed. Since the propulsion subsystem is modular in nature, it was completely checked, serviced, and tested independent of the spacecraft. Proper prediction of in-flight performance required the development of three significant modeling tools to predict and account for nitrogen saturation of the propellant during the six-month coast period and to predict and statistically analyze in-flight data. The flight performance of the subsystem was excellent, as were the performance prediction correlations. These correlations are presented.

Probabilistic Structural Analysis Methods for select space propulsion system components (PSAM). Volume 3: Literature surveys and technical reports

NASA Technical Reports Server (NTRS)

1992-01-01

The technical effort and computer code developed during the first year are summarized. Several formulations for Probabilistic Finite Element Analysis (PFEA) are described with emphasis on the selected formulation. The strategies being implemented in the first-version computer code to perform linear, elastic PFEA is described. The results of a series of select Space Shuttle Main Engine (SSME) component surveys are presented. These results identify the critical components and provide the information necessary for probabilistic structural analysis.

KSC-95pc586

NASA Image and Video Library

1995-04-17

KENNEDY SPACE CENTER, FLA. - Space Shuttle Main Engine (SSME) No. 2036, the first of the new Block 1 engines to fly, awaits installation into position one of the orbiter Discovery in Orbiter Processing Facility 2 during preparation of the spaceplane for the STS-70 mission. The advanced powerplant features a new high-pressure liquid oxygen turbopump, a two-duct powerhead, a baffleless main injector, a single-coil heat exchanger and start sequence modifications. These modifications are designed to improve both engine performance and safety.

Simulations of Flow Through the SSME LH2 Feed Line and LPFP Inducer

NASA Technical Reports Server (NTRS)

Dorney, Daniel J.; Rothermel, Jeffry

2003-01-01

During a post-flight inspection of the liquid hydrogen feed lines leading the Space Shuttle main engines cracks were discover in slots on a flow liner just upstream of the low pressure fuel pump inducer. Numerical simulations have been performed for the feed line, the flow liner (including the slots and backing cavity) and the inducer. The predicted results have been compared with experimental data taken during hot-fire tests at NASA Stennis Space Center.

Triple redundant computer system/display and keyboard subsystem interface

NASA Technical Reports Server (NTRS)

Gulde, F. J.

1973-01-01

Interfacing of the redundant display and keyboard subsystem with the triple redundant computer system is defined according to space shuttle design. The study is performed in three phases: (1) TRCS configuration and characteristics identification; (2) display and keyboard subsystem configuration and characteristics identification, and (3) interface approach definition.

Development of a preprototype times wastewater recovery subsystem: Appendices

NASA Technical Reports Server (NTRS)

Roebelen, G. J., Jr.; Dehner, G. F.

1984-01-01

This Master Test Plan outlines the test program to be performed by Hamilton Standard during the Urine Water Recovery Subsystem Program. Testing is divided into three phases: (1) design support testing; development component testing; and acceptance testing. The completion of this test program verifies the subsystem operation.

Auxiliary propulsion system flight package

NASA Technical Reports Server (NTRS)

Collett, C. R.

1987-01-01

Hughes Aircraft Company developed qualified and integrated flight, a flight test Ion Auxiliary Propulsion System (IAPS), on an Air Force technology satellite. The IAPS Flight Package consists of two identical Thruster Subsystems and a Diagnostic Subsystem. Each thruster subsystem (TSS) is comprised of an 8-cm ion Thruster-Gimbal-Beam Shield Unit (TGBSU); Power Electronics Unit; Digital Controller and Interface Unit (DCIU); and Propellant Tank, Valve and Feed Unit (PTVFU) plus the requisite cables. The Diagnostic Subsystem (DSS) includes four types of sensors for measuring the effect of the ion thrusters on the spacecraft and the surrounding plasma. Flight qualifications of IAPS, prior to installation on the spacecraft, consisted of performance, vibration and thermal-vacuum testing at the unit level, and thermal-vacuum testing at the subsystem level. Mutual compatibility between IAPS and the host spacecraft was demonstrated during a series of performance and environmental tests after the IAPS Flight Package was installed on the spacecraft. After a spacecraft acoustic test, performance of the ion thrusters was reverified by removing the TGBSUs for a thorough performance test at Hughes Research Laboratories (HRL). The TGBSUs were then reinstalled on the spacecraft. The IAPS Flight Package is ready for flight testing when Shuttle flights are resumed.

Space Station Freedom Environmental Control and Life Support System (ECLSS) phase 3 simplified integrated test trace contaminant control subsystem performance

NASA Technical Reports Server (NTRS)

Perry, J. L.

1990-01-01

Space Station Freedom environmental control and life support system testing has been conducted at Marshall Space Flight Center since 1986. The phase 3 simplified integrated test (SIT) conducted from July 30, 1989, through August 11, 1989, tested an integrated air revitalization system. During this test, the trace contaminant control subsystem (TCCS) was directly integrated with the bleed stream from the carbon dioxide reduction subsystem. The TCCS performed as expected with minor anomalies. The test set the basis for further characterizing the TCCS performance as part of advance air revitalization system configurations.

Characterization of a low concentrator photovoltaics module

NASA Astrophysics Data System (ADS)

Butler, B. A.; van Dyk, E. E.; Vorster, F. J.; Okullo, W.; Munji, M. K.; Booysen, P.

2012-05-01

Low concentration photovoltaic (LCPV) systems have the potential to reduce the cost per kWh of electricity compared to conventional flat-plate photovoltaics (PV) by up to 50%. The cost-savings are realised by replacing expensive PV cells with relatively cheaper optical components to concentrate incident solar irradiance onto a receiver and by tracking the sun along either 1 axis or 2 axes. A LCPV module consists of three interrelated subsystems, viz., the optical, electrical and the thermal subsystems, which must be considered for optimal module design and performance. Successful integration of these subsystems requires the balancing of cost, performance and reliability. In this study LCPV experimental prototype modules were designed, built and evaluated with respect to optimisation of the three subsystems and overall performance. This paper reports on the optical and electrical evaluation of a prototype LCPV module.

STS-60 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1994-01-01

The STS-60 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the sixtieth flight of the Space Shuttle Program and eighteenth flight of the Orbiter vehicle Discovery (OV-103). In addition to the Orbiter, the flight vehicle consisted of an ET designated at ET-61 (Block 10); three SSME's which were designated as serial numbers 2012, 2034, and 2032 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-062. The RSRM's that were installed in each SRB were designated as 360L035A (lightweight) for the left SRB, and 360Q035B (quarterweight) for the right SRB. This STS-60 Space Shuttle Program Mission Report fulfills the Space Shuttle Program requirement as documented in NSTS 07700, Volume VIII, Appendix E. That document requires that each major organizational element supporting the Program report the results of its hardware evaluation and mission performance plus identify all related in-flight anomalies. The primary objectives of the STS-60 mission were to deploy and retrieve the Wake Shield Facility-1 (WSF-1), and to activate the Spacehab-2 payload and perform on-orbit experiments. Secondary objectives of this flight were to activate and command the Capillary Pumped Loop/Orbital Debris Radar Calibration Spheres/Breman Satellite Experiment/Getaway Special (GAS) Bridge Assembly (CAPL/ODERACS/BREMSAT/GBA) payload, the Auroral Photography Experiment-B (APE-B), and the Shuttle Amateur Radio Experiment-II (SAREX-II).

Fort Hood Solar Total Energy Project. Volume II. Preliminary design. Part 1. System criteria and design description. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None,

1979-01-01

This volume documents the preliminary design developed for the Solar Total Energy System to be installed at Fort Hood, Texas. Current system, subsystem, and component designs are described and additional studies which support selection among significant design alternatives are presented. Overall system requirements which form the system design basis are presented. These include program objectives; performance and output load requirements; industrial, statutory, and regulatory standards; and site interface requirements. Material in this section will continue to be issued separately in the Systems Requirements Document and maintained current through revision throughout future phases of the project. Overall system design and detailedmore » subsystem design descriptions are provided. Consideration of operation and maintenance is reflected in discussion of each subsystem design as well as in an integrated overall discussion. Included are the solar collector subsystem; the thermal storage subsystem, the power conversion sybsystem (including electrical generation and distribution); the heating/cooling and domestic hot water subsystems; overall instrumentation and control; and the STES building and physical plant. The design of several subsystems has progressed beyond the preliminary stage; descriptions for such subsystems are therefore provided in more detail than others to provide complete documentation of the work performed. In some cases, preliminary design parameters require specific verificaton in the definitive design phase and are identified in the text. Subsystem descriptions will continue to be issued and revised separately to maintain accuracy during future phases of the project. (WHK)« less

Introduction to the scientific application system of DAMPE (On behalf of DAMPE collaboration)

NASA Astrophysics Data System (ADS)

Zang, Jingjing

2016-07-01

The Dark Matter Particle Explorer (DAMPE) is a high energy particle physics experiment satellite, launched on 17 Dec 2015. The science data processing and payload operation maintenance for DAMPE will be provided by the DAMPE Scientific Application System (SAS) at the Purple Mountain Observatory (PMO) of Chinese Academy of Sciences. SAS is consisted of three subsystems - scientific operation subsystem, science data and user management subsystem and science data processing subsystem. In cooperation with the Ground Support System (Beijing), the scientific operation subsystem is responsible for proposing observation plans, monitoring the health of satellite, generating payload control commands and participating in all activities related to payload operation. Several databases developed by the science data and user management subsystem of DAMPE methodically manage all collected and reconstructed science data, down linked housekeeping data, payload configuration and calibration data. Under the leadership of DAMPE Scientific Committee, this subsystem is also responsible for publication of high level science data and supporting all science activities of the DAMPE collaboration. The science data processing subsystem of DAMPE has already developed a series of physics analysis software to reconstruct basic information about detected cosmic ray particle. This subsystem also maintains the high performance computing system of SAS to processing all down linked science data and automatically monitors the qualities of all produced data. In this talk, we will describe all functionalities of whole DAMPE SAS system and show you main performances of data processing ability.

Conversion-Integration of MSFC Nonlinear Signal Diagnostic Analysis Algorithms for Realtime Execution of MSFC's MPP Prototype System

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi

1996-01-01

NASA's advanced propulsion system Small Scale Magnetic Disturbances/Advanced Technology Development (SSME/ATD) has been undergoing extensive flight certification and developmental testing, which involves large numbers of health monitoring measurements. To enhance engine safety and reliability, detailed analysis and evaluation of the measurement signals are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce the risk of catastrophic system failures and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. During the development of SSME, ASRI participated in the research and development of several advanced non- linear signal diagnostic methods for health monitoring and failure prediction in turbomachinery components. However, due to the intensive computational requirement associated with such advanced analysis tasks, current SSME dynamic data analysis and diagnostic evaluation is performed off-line following flight or ground test with a typical diagnostic turnaround time of one to two days. The objective of MSFC's MPP Prototype System is to eliminate such 'diagnostic lag time' by achieving signal processing and analysis in real-time. Such an on-line diagnostic system can provide sufficient lead time to initiate corrective action and also to enable efficient scheduling of inspection, maintenance and repair activities. The major objective of this project was to convert and implement a number of advanced nonlinear diagnostic DSP algorithms in a format consistent with that required for integration into the Vanderbilt Multigraph Architecture (MGA) Model Based Programming environment. This effort will allow the real-time execution of these algorithms using the MSFC MPP Prototype System. ASRI has completed the software conversion and integration of a sequence of nonlinear signal analysis techniques specified in the SOW for real-time execution on MSFC's MPP Prototype. This report documents and summarizes the results of the contract tasks; provides the complete computer source code; including all FORTRAN/C Utilities; and all other utilities/supporting software libraries that are required for operation.

SSME leak detection feasibility investigation by utilization of infrared sensor technology

NASA Technical Reports Server (NTRS)

Shohadaee, Ahmad A.; Crawford, Roger A.

1990-01-01

This investigation examined the potential of using state-of-the-art technology of infrared (IR) thermal imaging systems combined with computer, digital image processing and expert systems for Space Shuttle Main Engines (SSME) propellant path peak detection as an early warning system of imminent engine failure. A low-cost, laboratory experiment was devised and an experimental approach was established. The system was installed, checked out, and data were successfully acquired demonstrating the proof-of-concept. The conclusion from this investigation is that both numerical and experimental results indicate that the leak detection by using infrared sensor technology proved to be feasible for a rocket engine health monitoring system.

Space Shuttle Main Engine Off-Nominal Low Power Level Operation

NASA Technical Reports Server (NTRS)

Bradley, Michael

1997-01-01

This paper describes Rocketdyne's successful analysis and demonstration of the Space Shuttle Main Engine (SSME) operation at off-nominal power levels during Reusable Launch Vehicle (RLV) evaluation tests. The nominal power level range for the SSME is from 65% rated power level (RPL) to 109% RPL. Off-nominal power levels incrementally demonstrated were: 17% RPL, 22% RPL, 27% RPL, 40% RPL, 45% RPL, and 50% RPL. Additional achievements during low power operation included: use of a hydrostatic bearing High Pressure Oxidizer Turbopump (HPOTP), nominal High Pressure Fuel Turbopump (HPFTP) first rotor critical speed operation, combustion stability at low power levels, and refined definition of nozzle flow separation heat loads.

Identification and detection of anomalies through SSME data analysis

NASA Technical Reports Server (NTRS)

Pereira, Lisa; Ali, Moonis

1990-01-01

The goal of the ongoing research described in this paper is to analyze real-time ground test data in order to identify patterns associated with the anomalous engine behavior, and on the basis of this analysis to develop an expert system which detects anomalous engine behavior in the early stages of fault development. A prototype of the expert system has been developed and tested on the high frequency data of two SSME tests, namely Test #901-0516 and Test #904-044. The comparison of our results with the post-test analyses indicates that the expert system detected the presence of the anomalies in a significantly early stage of fault development.

Main propulsion system test requirements for the two-engine Shuttle-C

NASA Technical Reports Server (NTRS)

Lynn, E. E.; Platt, G. K.

1989-01-01

The Shuttle-C is an unmanned cargo carrying derivative of the space shuttle with optional two or three space shuttle main engines (SSME's), whereas the shuttle has three SSME's. Design and operational differences between the Shuttle-C and shuttle were assessed to determine requirements for additional main propulsion system (MPS) verification testing. Also, reviews were made of the shuttle main propulsion test program objectives and test results and shuttle flight experience. It was concluded that, if significant MPS modifications are not made beyond those currently planned, then main propulsion system verification can be concluded with an on-pad flight readiness firing.

SSME/side loads analysis for flight configuration, revision A. [structural analysis of space shuttle main engine under side load excitation

NASA Technical Reports Server (NTRS)

Holland, W.

1974-01-01

This document describes the dynamic loads analysis accomplished for the Space Shuttle Main Engine (SSME) considering the side load excitation associated with transient flow separation on the engine bell during ground ignition. The results contained herein pertain only to the flight configuration. A Monte Carlo procedure was employed to select the input variables describing the side load excitation and the loads were statistically combined. This revision includes an active thrust vector control system representation and updated orbiter thrust structure stiffness characteristics. No future revisions are planned but may be necessary as system definition and input parameters change.

Probabilistic evaluation of SSME structural components

NASA Astrophysics Data System (ADS)

Rajagopal, K. R.; Newell, J. F.; Ho, H.

1991-05-01

The application is described of Composite Load Spectra (CLS) and Numerical Evaluation of Stochastic Structures Under Stress (NESSUS) family of computer codes to the probabilistic structural analysis of four Space Shuttle Main Engine (SSME) space propulsion system components. These components are subjected to environments that are influenced by many random variables. The applications consider a wide breadth of uncertainties encountered in practice, while simultaneously covering a wide area of structural mechanics. This has been done consistent with the primary design requirement for each component. The probabilistic application studies are discussed using finite element models that have been typically used in the past in deterministic analysis studies.

STS-38 Atlantis, OV-104, lifts off from KSC LC Pad during night launch

NASA Technical Reports Server (NTRS)

1990-01-01

STS-38 Atlantis, Orbiter Vehicle (OV) 104, lifts off from Kennedy Space Center (KSC) Launch Complex (LC) Pad at 6:48:15:0639 pm (Eastern Standard Time (EST)) for Department of Defense (DOD)-devoted mission. OV-104, atop the external tank (ET) and flanked by solid rocket boosters (SRBs), is almost clear of the launch tower which is lit up by the SRB and space shuttle main engine (SSME) firings. Spotlight equipment is silhouetted against the SRB/SSME glow in the foreground. The retracted rotating service structure (RSS) is highlighted against the evening darkness by the launch fireworks.

Investigation of SSME alternate high pressure fuel turbopump lift-off seal fluid and structural dynamic interaction

NASA Technical Reports Server (NTRS)

Elrod, David A.

1989-01-01

The Space Shuttle main engine (SSME) alternate turbopump development program (ATD) high pressure fuel turbopump (HPFTP) design utilizes an innovative lift-off seal (LOS) design that is located in close proximity to the turbine end bearing. Cooling flow exiting the bearing passes through the lift-off seal during steady state operation. The potential for fluid excitation of lift-off seal structural resonances is investigated. No fluid excitation of LOS resonances is predicted. However, if predicted LOS natural frequencies are significantly lowered by the presence of the coolant, pressure oscillations caused by synchronous whirl of the HPFTP rotor may excite a resonance.

Quantifying uncertainties in the structural response of SSME blades

NASA Technical Reports Server (NTRS)

Nagpal, Vinod K.

1987-01-01

To quantify the uncertainties associated with the geometry and material properties of a Space Shuttle Main Engine (SSME) turbopump blade, a computer code known as STAEBL was used. A finite element model of the blade used 80 triangular shell elements with 55 nodes and five degrees of freedom per node. The whole study was simulated on the computer and no real experiments were conducted. The structural response has been evaluated in terms of three variables which are natural frequencies, root (maximum) stress, and blade tip displacements. The results of the study indicate that only the geometric uncertainties have significant effects on the response. Uncertainties in material properties have insignificant effects.

The design and evolution of the beta two-stage-to-orbit horizontal takeoff and landing launch system

NASA Technical Reports Server (NTRS)

Burkardt, Leo A.; Norris, Rick B.

1992-01-01

The Beta launch system was originally conceived in 1986 as a horizontal takeoff and landing, fully reusable, two-stage-to-orbit, manned launch vehicle to replace the Shuttle. It was to be capable of delivering a 50,000 lb. payload to low polar orbit. The booster propulsion system consisted of JP fueled turbojets and LH fueled ramjets mounted in pods in an over/under arrangement, and a single LOX/LH fueled SSME rocket. The second stage orbiter, which staged at Mach 8, was powered by an SSME rocket. A major goal was to develop a vehicle design consistent with near term technology. The vehicle design was completed with a GLOW of approximately 2,000,000 lbs. All design goals were met. Since then, interest has shifted to the 10,000 lbs. to low polar orbit payload class. The original Beta was down-sized to meet this payload class. The GLOW of the down-sized vehicle was approximately 1,000,000 lbs. The booster was converted to exclusively air-breathing operation. Because the booster depends on conventional air-breathing propulsion only, the staging Mach number was reduced to 5.5. The orbiter remains an SSME rocket-powered stage.

SSME component assembly and life management expert system

NASA Technical Reports Server (NTRS)

Ali, M.; Dietz, W. E.; Ferber, H. J.

1989-01-01

The space shuttle utilizes several rocket engine systems, all of which must function with a high degree of reliability for successful mission completion. The space shuttle main engine (SSME) is by far the most complex of the rocket engine systems and is designed to be reusable. The reusability of spacecraft systems introduces many problems related to testing, reliability, and logistics. Components must be assembled from parts inventories in a manner which will most effectively utilize the available parts. Assembly must be scheduled to efficiently utilize available assembly benches while still maintaining flight schedules. Assembled components must be assigned to as many contiguous flights as possible, to minimize component changes. Each component must undergo a rigorous testing program prior to flight. In addition, testing and assembly of flight engines and components must be done in conjunction with the assembly and testing of developmental engines and components. The development, testing, manufacture, and flight assignments of the engine fleet involves the satisfaction of many logistical and operational requirements, subject to many constraints. The purpose of the SSME Component Assembly and Life Management Expert System (CALMES) is to assist the engine assembly and scheduling process, and to insure that these activities utilize available resources as efficiently as possible.

General view of the Space Shuttle Main Engine (SSME) assembly ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-pressure oxidizer Turbopump discharge Duct looping from the upper left side of the engine assembly to the lower left side of the assembly, the Low-Pressure Fuel Turbopump (LPFTP) is on the upper left of the assembly in this view and the LPFTP Discharge Duct loops from the upper left to upper right then turns back and down the assembly to the High-Pressure Fuel Turbopump on the lower right of the assembly. The Engine Controller and the Main fuel Valve Hydraulic Actuator are on the lower left portion of the assembly. The vertical rod that is in the approximate center of the engine assembly is a piece of ground support equipment call a Gimbal Actuator Replacement Strut which are used on the SSMEs when they are not installed in an orbiter. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

General view of the Space Shuttle Main Engine (SSME) assembly ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General view of the Space Shuttle Main Engine (SSME) assembly with the expansion nozzle removed and resting on a cushioned mat on the floor of the SSME Processing Facility. The most prominent features in this view are the Low-pressure Fuel Turbopump discharge Duct looping from the upper left side of the engine assembly to the lower left side of the assembly, the Low-Pressure Oxidizer Turbopump (LPOTP) is on the upper left of the assembly in this view and the LPOTP Discharge Duct loops from the upper left to upper right. The sphere in the middle right side of the assembly in this view is the POGO System Accumulator , the partial sphere to its left and slightly more toward the center of the assembly is the Heat Exchanger on the Oxidizer Preburner side of the Hot Gas Manifold, beneath that is the High-Pressure Oxidizer Turbopump (HPOTP) and the HPOTP Discharge duct loops from the pump around to the lower left of the assembly. The Pneumatic Control Assembly is in the approximate center of the engine assembly in this view. - Space Transportation System, Space Shuttle Main Engine, Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Calibrator tests of heat flux gauges mounted in SSME blades

NASA Technical Reports Server (NTRS)

Liebert, Curt H.

1989-01-01

Measurements of heat flux to space shuttle main engine (SSME) turbine blade surfaces are being made in the Lewis heat flux calibration facility. Surface heat flux information is obtained from transient temperature measurements taken at points within the gauge. A 100-kW Vortek arc lamp is used as a source of thermal radiant energy. Thermoplugs, with diameters of about 0.190 cm and lengths varying from about 0.190 to 0.320 cm, are being investigated. The thermoplug is surrounded on all surfaces except the active surface by a pocket of air located in the circular annulus and under the back cover. Since the thermoplug is insulated, it is assumed that heat is conducted in a one-dimensional manner from the hot active surface to the cooler back side of the thermoplug. It is concluded that the miniature plug-type gauge concept is feasible for measurement of blade surface heat flux. It is suggested that it is important to measure heat flux near the hub on the suction surface and at the throat on SSME blades rotating in engines because stress and heat transfer coefficients are high in this region.

STS-61 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1994-01-01

The STS-61 Space Shuttle Program Mission Report summarizes the Hubble Space Telescope (HST) servicing mission as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the fifty-ninth flight of the Space Shuttle Program and fifth flight of the Orbiter vehicle Endeavour (OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET designated as ET-60; three SSME's which were designated as serial numbers 2019, 2033, and 2017 in positions 1, 2, and 3, respectively; and two SRB's which were designated BI-063. The RSRM's that were installed in each SRB were designated as 360L023A (lightweight) for the left SRB, and 360L023B (lightweight) for the right SRB. This STS-61 Space Shuttle Program Mission Report fulfills the Space Shuttle Program requirement as documented in NSTS 07700, Volume 8, Appendix E. That document requires that each major organizational element supporting the Program report the results of its hardware evaluation and mission performance plus identify all related in-flight anomalies. The primary objective of the STS-61 mission was to perform the first on-orbit servicing of the Hubble Space Telescope. The servicing tasks included the installation of new solar arrays, replacement of the Wide Field/Planetary Camera I (WF/PC I) with WF/PC II, replacement of the High Speed Photometer (HSP) with the Corrective Optics Space Telescope Axial Replacement (COSTAR), replacement of rate sensing units (RSU's) and electronic control units (ECU's), installation of new magnetic sensing systems and fuse plugs, and the repair of the Goddard High Resolution Spectrometer (GHRS). Secondary objectives were to perform the requirements of the IMAX Cargo Bay Camera (ICBC), the IMAX Camera, and the Air Force Maui Optical Site (AMOS) Calibration Test.

Lunar Surface-to-Surface Power Transfer

NASA Technical Reports Server (NTRS)

Kerslake, Thomas W.

2007-01-01

A human lunar outpost, under NASA study for construction in the 2020's, has potential requirements to transfer electric power up to 50-kW across the lunar surface from 0.1 to 10-km distances. This power would be used to operate surface payloads located remotely from the outpost and/or outpost primary power grid. This paper describes concept designs for state-of-the-art technology power transfer subsystems including AC or DC power via cables, beamed radio frequency power and beamed laser power. Power transfer subsystem mass and performance are calculated and compared for each option. A simplified qualitative assessment of option operations, hazards, costs and technology needs is also described. Based on these concept designs and performance analyses, a DC power cabling subsystem is recommended to minimize subsystem mass and to minimize mission and programmatic costs and risks. Avenues for additional power transfer subsystem studies are recommended.

A miniaturized glucose biosensor for in vitro and in vivo studies.

PubMed

Yang, Yang-Li; Huang, Jian-Feng; Tseng, Ta-Feng; Lin, Chia-Ching; Lou, Shyh-Liang

2008-01-01

A miniaturized wireless glucose biosensor has been developed to perform in vitro and in vivo studies. It consists of an external control subsystem and an implant sensing subsystem. The implant subsystem consists of a micro-processor, which coordinates circuitries of radio frequency, power regulator, command demodulator, glucose sensing trigger and signal read-out. Except for a set of sensing electrodes, the micro-processor, the circuitries and a receiving coil were hermetically sealed with polydimethylsiloxane. The electrode set is a substrate of silicon oxide coated with platinum, which includes a working electrode and a reference electrode. Glucose oxidase was immobilized on the surface of the working electrode. The implant subsystem bi-directionally communicates with the external subsystem via radio frequency technologies. The external subsystem wirelessly supplies electricity to power the implant, issues commands to the implant to perform tasks, receives the glucose responses detected by the electrode, and relays the response signals to a computer through a RS-232 connection. Studies of in vitro and in vivo were performed to evaluate the biosensor. The linear response of the biosensor is up to 15 mM of glucose in vitro. The results of in vivo study show significant glucose variations measured from the interstitial tissue fluid of a diabetes rat in fasting and non-fasting periods.

ALSSAT Development Status

NASA Technical Reports Server (NTRS)

Yeh, H. Y. Jannivine; Brown, Cheryl B.; Jeng, Frank F.; Anderson, Molly; Ewert, Michael K.

2009-01-01

The development of the Advanced Life Support (ALS) Sizing Analysis Tool (ALSSAT) using Microsoft(Registered TradeMark) Excel was initiated by the Crew and Thermal Systems Division (CTSD) of Johnson Space Center (JSC) in 1997 to support the ALS and Exploration Offices in Environmental Control and Life Support System (ECLSS) design and studies. It aids the user in performing detailed sizing of the ECLSS for different combinations of the Exploration Life support (ELS) regenerative system technologies. This analysis tool will assist the user in performing ECLSS preliminary design and trade studies as well as system optimization efficiently and economically. The latest ALSSAT related publication in ICES 2004 detailed ALSSAT s development status including the completion of all six ELS Subsystems (ELSS), namely, the Air Management Subsystem, the Biomass Subsystem, the Food Management Subsystem, the Solid Waste Management Subsystem, the Water Management Subsystem, and the Thermal Control Subsystem and two external interfaces, including the Extravehicular Activity and the Human Accommodations. Since 2004, many more regenerative technologies in the ELSS were implemented into ALSSAT. ALSSAT has also been used for the ELS Research and Technology Development Metric Calculation for FY02 thru FY06. It was also used to conduct the Lunar Outpost Metric calculation for FY08 and was integrated as part of a Habitat Model developed at Langley Research Center to support the Constellation program. This paper will give an update on the analysis tool s current development status as well as present the analytical results of one of the trade studies that was performed.

Some special sub-systems for stratospheric balloon flights in India

NASA Astrophysics Data System (ADS)

Damle, S. V.; Gokhale, G. S.; Kundapurkar, R. U.

During last few years several new sub-systems for balloon were developed and are being regularly used in the balloon flights. Some of these sub-systems are i) positive monitor for magnetic ballast release using an opto-electronic device ii) one-way pressure switch to terminate flight for runaway balloon iii) in-flight payload reel down system for atmospheric science experiment. The design, usage and performance of these and other sub-systems will be presented.

TOPEX satellite concept. TOPEX option study report

NASA Technical Reports Server (NTRS)

Meyer, D. P.; Case, C. M.

1982-01-01

Candidate bus equipment from the Viking, Applications Explorer Mission, and Small Scientific Satellite programs for application to the TOPEX mission options is assessed. Propulsion module equipment and subsystem candidates from the Applications Explorer Mission satellites and the Small Scientific Satellite spacecraft are evaluated for those TOPEX options. Several subsystem concepts appropriate to the TOPEX options are described. These descriptions consider performance characteristics of the subsystems. Cost and availability information on the candidate equipment and subsystems are also provided.

The 30-centimeter ion thrust subsystem design manual

NASA Technical Reports Server (NTRS)

1979-01-01

The principal characteristics of the 30-centimeter ion propulsion thrust subsystem technology that was developed to satisfy the propulsion needs of future planetary and early orbital missions are described. Functional requirements and descriptions, interface and performance requirements, and physical characteristics of the hardware are described at the thrust subsystem, BIMOD engine system, and component level.

Apollo experience report: Lunar module environmental control subsystem

NASA Technical Reports Server (NTRS)

Gillen, R. J.; Brady, J. C.; Collier, F.

1972-01-01

A functional description of the environmental control subsystem is presented. Development, tests, checkout, and flight experiences of the subsystem are discussed; and the design fabrication, and operational difficulties associated with the various components and subassemblies are recorded. Detailed information is related concerning design changes made to, and problems encountered with, the various elements of the subsystem, such as the thermal control water sublimator, the carbon dioxide sensing and control units, and the water section. The problems associated with water sterilization, water/glycol formulation, and materials compatibility are discussed. The corrective actions taken are described with the expection that this information may be of value for future subsystems. Although the main experiences described are problem oriented, the subsystem has generally performed satisfactorily in flight.

Research and implementation on improving I/O performance of streaming media storage system

NASA Astrophysics Data System (ADS)

Lu, Zheng-wu; Wang, Yu-de; Jiang, Guo-song

2008-12-01

In this paper, we study the special requirements of a special storage system: streaming media server, and propose a solution to improve I/O performance of RAID storage system. The solution is suitable for streaming media applications. A streaming media storage subsystem includes the I/O interfaces, RAID arrays, I/O scheduling and device drivers. The solution is implemented on the top of the storage subsystem I/O Interface. Storage subsystem is the performance bottlenecks of a streaming media system, and I/O interface directly affect the performance of the storage subsystem. According to theoretical analysis, 64 KB block-size is most appropriate for streaming media applications. We carry out experiment in detail, and verified that the proper block-size really is 64KB. It is in accordance with our analysis. The experiment results also show that by using DMA controller, efficient memory management technology and mailbox interface design mechanism, streaming media storage system achieves a high-speed data throughput.

Spacelab output processing system architectural study

NASA Technical Reports Server (NTRS)

1977-01-01

Two different system architectures are presented. The two architectures are derived from two different data flows within the Spacelab Output Processing System. The major differences between these system architectures are in the position of the decommutation function (the first architecture performs decommutation in the latter half of the system and the second architecture performs that function in the front end of the system). In order to be examined, the system was divided into five stand-alone subsystems; Work Assembler, Mass Storage System, Output Processor, Peripheral Pool, and Resource Monitor. The work load of each subsystem was estimated independent of the specific devices to be used. The candidate devices were surveyed from a wide sampling of off-the-shelf devices. Analytical expressions were developed to quantify the projected workload in conjunction with typical devices which would adequately handle the subsystem tasks. All of the study efforts were then directed toward preparing performance and cost curves for each architecture subsystem.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: METSAT (S/N 108) AMSU-A1 Receiver Assemblies, P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05

NASA Technical Reports Server (NTRS)

Haigh, R.; Krimchansky, S. (Technical Monitor)

2000-01-01

This is the Performance Verification Report, METSAT (S/N 108) AMSU-A1 Receiver Assemblies P/N 1356429-1 S/N F05 and P/N 1356409-1 S/N F05, for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A). The ATP for the AMSU-A Receiver Subsystem, AE-26002/6A, is prepared to describe in detail the configuration of the test setups and the procedures of the tests to verify that the receiver subsystem meets the specifications as required either in the AMSU-A Instrument Performance and Operation Specifications, S-480-80, or in AMSU-A Receiver Subsystem Specifications, AE-26608, derived by the Aerojet System Engineering. Test results that verify the conformance to the specifications demonstrate the acceptability of that particular receiver subsystem.

STS-76 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1996-01-01

The STS-76 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-sixth flight of the Space Shuttle Program, the fifty-first flight since the return-to-flight, and the sixteenth flight of the Orbiter Atlantis (OV-104). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-77; three SSME's that were designated as serial numbers 2035, 2109, and 2019 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-079. The RSRM's, designated RSRM-46, were installed in each SRB and the individual RSRM's were designated as 360TO46A for the left SRB, and 360TO46B for the right SRB. The primary objectives of this flight were to rendezvous and dock with the Mir Space Station and transfer one U.S. Astronaut to the Mir. A single Spacehab module carried science equipment and hardware, Risk Mitigation Experiments (RME's), and Russian Logistics in support of the Phase 1 Program requirements. In addition, the European Space Agency (ESA) Biorack operations were performed. Appendix A lists the sources of data, both formal and informal, that were used to prepare this report. Appendix B provides the definition of acronyms and abbreviations used throughout the report. All times during the flight are given in Greenwich mean time (GMT) and mission elapsed time (MET).

STS-75 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1996-01-01

The STS-75 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-fifth flight of the Space Shuttle Program, the fiftieth flight since the return-to-flight, and the nineteenth flight of the Orbiter Columbia (OV-102). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-76; three SSME's that were designated as serial numbers 2029, 2034, and 2017 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-078. The RSRM's, designated RSRM-53, were installed in each SRB and the individual RSRMs were designated as 36OW53A for the left SRB, and 36OW053B for the right SRB. The primary objectives of this flight were to perform the operations necessary to fulfill the requirements of the Tethered Satellite System-1 R (TSS-1R), and the United States Microgravity Payload-3 (USMP-3). The secondary objectives were to complete the operations of the Orbital Acceleration Research Experiment (OARE), and to meet the requirements of the Middeck Glovebox (MGBX) facility and the Commercial Protein Crystal Growth (CPCG) experiment. Appendix A provides the definition of acronyms and abbreviations used thorughout the report. All times during the flight are given in Greenwich mean time (GMT) and mission elapsed time (MET).

System model the processing of heterogeneous sensory information in robotized complex

NASA Astrophysics Data System (ADS)

Nikolaev, V.; Titov, V.; Syryamkin, V.

2018-05-01

Analyzed the scope and the types of robotic systems consisting of subsystems of the form "a heterogeneous sensors data processing subsystem". On the basis of the Queuing theory model is developed taking into account the unevenness of the intensity of information flow from the sensors to the subsystem of information processing. Analytical solution to assess the relationship of subsystem performance and uneven flows. The research of the obtained solution in the range of parameter values of practical interest.

Development of a HTS transceiver sub-system for 3G mobile communication TD-SCDMA base station

NASA Astrophysics Data System (ADS)

Zhang, Xueqiang; He, Xiaofeng; Wang, Yuehui; Duan, Tao; Wang, Guizhen; Zhang, Yan; Li, Chunguang; Zhang, Qiang; Li, Hong; He, Yusheng

2010-02-01

A prototype of a high temperature superconducting (HTS) transceiver sub-system for applications in a TD-SCDMA, one of the third generation (3G) communication standards, base station has been developed. Both the HTS sub-system and the conventional counterpart have been implemented into a TD-SCDMA commercial communication network and comparison test studies were carried out. The measured results showed that the HTS sub-system could remarkably improve the RF performance of both transmitting and receiving chains.

Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

NASA Technical Reports Server (NTRS)

Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

2010-01-01

Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, in a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation; testing results, and other information. Where appropriate, actual performance history was used for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to verify compliance with requirements and to highlight design or performance shortcomings for further decision-making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability and maintainability analysis, and present findings and observation based on analysis leading to the Ground Systems Preliminary Design Review milestone.

LEADER - An integrated engine behavior and design analyses based real-time fault diagnostic expert system for Space Shuttle Main Engine (SSME)

NASA Technical Reports Server (NTRS)

Gupta, U. K.; Ali, M.

1989-01-01

The LEADER expert system has been developed for automatic learning tasks encompassing real-time detection, identification, verification, and correction of anomalous propulsion system operations, using a set of sensors to monitor engine component performance to ascertain anomalies in engine dynamics and behavior. Two diagnostic approaches are embodied in LEADER's architecture: (1) learning and identifying engine behavior patterns to generate novel hypotheses about possible abnormalities, and (2) the direction of engine sensor data processing to perform resoning based on engine design and functional knowledge, as well as the principles of the relevant mechanics and physics.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: Antenna Drive Subsystem METSAT AMSU-A2 (PN:1331200-2, SN:108)

NASA Technical Reports Server (NTRS)

Haapala, C.

1999-01-01

This is the Performance Verification Report, Antenna Drive Subassembly, Antenna Drive Subsystem, METSAT AMSU-A2 (P/N 1331200-2, SN: 108), for the Integrated Advanced Microwave Sounding Unit-A (AMSU-A).

Automatic control of a primary electric thrust subsystem

NASA Technical Reports Server (NTRS)

Macie, T. W.; Macmedan, M. L.

1975-01-01

A concept for automatic control of the thrust subsystem has been developed by JPL and participating NASA Centers. This paper reports on progress in implementing the concept at JPL. Control of the Thrust Subsystem (TSS) is performed by the spacecraft computer command subsystem, and telemetry data is extracted by the spacecraft flight data subsystem. The Data and Control Interface Unit, an element of the TSS, provides the interface with the individual elements of the TSS. The control philosophy and implementation guidelines are presented. Control requirements are listed, and the control mechanism, including the serial digital data intercommunication system, is outlined. The paper summarizes progress to Fall 1974.

Advanced life support control/monitor instrumentation concepts for flight application

NASA Technical Reports Server (NTRS)

Heppner, D. B.; Dahlhausen, M. J.; Fell, R. B.

1986-01-01

Development of regenerative Environmental Control/Life Support Systems requires instrumentation characteristics which evolve with successive development phases. As the development phase moves toward flight hardware, the system availability becomes an important design aspect which requires high reliability and maintainability. This program was directed toward instrumentation designs which incorporate features compatible with anticipated flight requirements. The first task consisted of the design, fabrication and test of a Performance Diagnostic Unit. In interfacing with a subsystem's instrumentation, the Performance Diagnostic Unit is capable of determining faulty operation and components within a subsystem, perform on-line diagnostics of what maintenance is needed and accept historical status on subsystem performance as such information is retained in the memory of a subsystem's computerized controller. The second focus was development and demonstration of analog signal conditioning concepts which reduce the weight, power, volume, cost and maintenance and improve the reliability of this key assembly of advanced life support instrumentation. The approach was to develop a generic set of signal conditioning elements or cards which can be configured to fit various subsystems. Four generic sensor signal conditioning cards were identified as being required to handle more than 90 percent of the sensors encountered in life support systems. Under company funding, these were detail designed, built and successfully tested.

FBI fingerprint identification automation study: AIDS 3 evaluation report. Volume 9: Functional requirements

NASA Technical Reports Server (NTRS)

1980-01-01

The current system and subsystem used by the Identification Division are described. System constraints that dictate the system environment are discussed and boundaries within which solutions must be found are described. The functional requirements were related to the performance requirements. These performance requirements were then related to their applicable subsystems. The flow of data, documents, or other pieces of information from one subsystem to another or from the external world into the identification system is described. Requirements and design standards for a computer based system are presented.

Engine Data Interpretation System (EDIS)

NASA Technical Reports Server (NTRS)

Cost, Thomas L.; Hofmann, Martin O.

1990-01-01

A prototype of an expert system was developed which applies qualitative or model-based reasoning to the task of post-test analysis and diagnosis of data resulting from a rocket engine firing. A combined component-based and process theory approach is adopted as the basis for system modeling. Such an approach provides a framework for explaining both normal and deviant system behavior in terms of individual component functionality. The diagnosis function is applied to digitized sensor time-histories generated during engine firings. The generic system is applicable to any liquid rocket engine but was adapted specifically in this work to the Space Shuttle Main Engine (SSME). The system is applied to idealized data resulting from turbomachinery malfunction in the SSME.

On an LAS-integrated soft PLC system based on WorldFIP fieldbus.

PubMed

Liang, Geng; Li, Zhijun; Li, Wen; Bai, Yan

2012-01-01

Communication efficiency is lowered and real-time performance is not good enough in discrete control based on traditional WorldFIP field intelligent nodes in case that the scale of control in field is large. A soft PLC system based on WorldFIP fieldbus was designed and implemented. Link Activity Scheduler (LAS) was integrated into the system and field intelligent I/O modules acted as networked basic nodes. Discrete control logic was implemented with the LAS-integrated soft PLC system. The proposed system was composed of configuration and supervisory sub-systems and running sub-systems. The configuration and supervisory sub-system was implemented with a personal computer or an industrial personal computer; running subsystems were designed and implemented based on embedded hardware and software systems. Communication and schedule in the running subsystem was implemented with an embedded sub-module; discrete control and system self-diagnosis were implemented with another embedded sub-module. Structure of the proposed system was presented. Methodology for the design of the sub-systems was expounded. Experiments were carried out to evaluate the performance of the proposed system both in discrete and process control by investigating the effect of network data transmission delay induced by the soft PLC in WorldFIP network and CPU workload on resulting control performances. The experimental observations indicated that the proposed system is practically applicable. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Conflicting Demands of Abstract and Specific Visual Object Processing Resolved by Fronto-Parietal Networks

PubMed Central

McMenamin, Brenton W.; Marsolek, Chad J.; Morseth, Brianna K.; Speer, MacKenzie F.; Burton, Philip C.; Burgund, E. Darcy

2016-01-01

Object categorization and exemplar identification place conflicting demands on the visual system, yet humans easily perform these fundamentally contradictory tasks. Previous studies suggest the existence of dissociable visual processing subsystems to accomplish the two abilities – an abstract category (AC) subsystem that operates effectively in the left hemisphere, and a specific exemplar (SE) subsystem that operates effectively in the right hemisphere. This multiple subsystems theory explains a range of visual abilities, but previous studies have not explored what mechanisms exist for coordinating the function of multiple subsystems and/or resolving the conflicts that would arise between them. We collected functional MRI data while participants performed two variants of a cue-probe working memory task that required AC or SE processing. During the maintenance phase of the task, the bilateral intraparietal sulcus (IPS) exhibited hemispheric asymmetries in functional connectivity consistent with exerting proactive control over the two visual subsystems: greater connectivity to the left hemisphere during the AC task, and greater connectivity to the right hemisphere during the SE task. Moreover, probe-evoked activation revealed activity in a broad fronto-parietal network (containing IPS) associated with reactive control when the two visual subsystems were in conflict, and variations in this conflict signal across trials was related to the visual similarity of the cue/probe stimulus pairs. Although many studies have confirmed the existence of multiple visual processing subsystems, this study is the first to identify the mechanisms responsible for coordinating their operations. PMID:26883940

Conflicting demands of abstract and specific visual object processing resolved by frontoparietal networks.

PubMed

McMenamin, Brenton W; Marsolek, Chad J; Morseth, Brianna K; Speer, MacKenzie F; Burton, Philip C; Burgund, E Darcy

2016-06-01

Object categorization and exemplar identification place conflicting demands on the visual system, yet humans easily perform these fundamentally contradictory tasks. Previous studies suggest the existence of dissociable visual processing subsystems to accomplish the two abilities-an abstract category (AC) subsystem that operates effectively in the left hemisphere and a specific exemplar (SE) subsystem that operates effectively in the right hemisphere. This multiple subsystems theory explains a range of visual abilities, but previous studies have not explored what mechanisms exist for coordinating the function of multiple subsystems and/or resolving the conflicts that would arise between them. We collected functional MRI data while participants performed two variants of a cue-probe working memory task that required AC or SE processing. During the maintenance phase of the task, the bilateral intraparietal sulcus (IPS) exhibited hemispheric asymmetries in functional connectivity consistent with exerting proactive control over the two visual subsystems: greater connectivity to the left hemisphere during the AC task, and greater connectivity to the right hemisphere during the SE task. Moreover, probe-evoked activation revealed activity in a broad frontoparietal network (containing IPS) associated with reactive control when the two visual subsystems were in conflict, and variations in this conflict signal across trials was related to the visual similarity of the cue-probe stimulus pairs. Although many studies have confirmed the existence of multiple visual processing subsystems, this study is the first to identify the mechanisms responsible for coordinating their operations.

SSME - Materials and Methods for Addressing High-Pressure Hydrogen Embrittlement

NASA Technical Reports Server (NTRS)

Matejczk, Daniel; Russell, Dale; Frandsen, Jon; Swanson, Greg

2010-01-01

From the humid, corrosion-friendly atmosphere of KSC, to the extreme heat of ascent, to the cold vacuum of space, the Space Shuttle faced one hostile environment after another. One of those harsh environments the hydrogen environment existed within the shuttle itself. Liquid hydrogen was the fuel that powered the shuttle s complex, powerful, and reusable main engine. Hydrogen provided the high specific impulse the bang per pound of fuel needed to perform the shuttle s heavy lifting duties. Hydrogen, however, was also a potential threat to the very metal of the propulsion system that used it. The diffusion of hydrogen atoms into a metal can make it more brittle and prone to cracking a process called hydrogen embrittlement. This effect can reduce the toughness of carefully selected and prepared materials. A concern that exposure to hydrogen might encourage crack growth was present from the beginning of the Space Shuttle Program, but the rationale for using hydrogen was compelling. This paper outlines the material characterization, anomaly resolution, and path to understanding of hydrogen embrittlement on superalloys through the course of the SSME program. Specific examples of nickel alloy turbine housings and single crystal turbine blades are addressed. The evolution of fracture mechanics analytical methods is also addressed.

Probabilistic evaluation of uncertainties and risks in aerospace components

NASA Technical Reports Server (NTRS)

Shah, A. R.; Shiao, M. C.; Nagpal, V. K.; Chamis, C. C.

1992-01-01

This paper summarizes a methodology developed at NASA Lewis Research Center which computationally simulates the structural, material, and load uncertainties associated with Space Shuttle Main Engine (SSME) components. The methodology was applied to evaluate the scatter in static, buckling, dynamic, fatigue, and damage behavior of the SSME turbo pump blade. Also calculated are the probability densities of typical critical blade responses, such as effective stress, natural frequency, damage initiation, most probable damage path, etc. Risk assessments were performed for different failure modes, and the effect of material degradation on the fatigue and damage behaviors of a blade were calculated using a multi-factor interaction equation. Failure probabilities for different fatigue cycles were computed and the uncertainties associated with damage initiation and damage propagation due to different load cycle were quantified. Evaluations on the effects of mistuned blades on a rotor were made; uncertainties in the excitation frequency were found to significantly amplify the blade responses of a mistuned rotor. The effects of the number of blades on a rotor were studied. The autocorrelation function of displacements and the probability density function of the first passage time for deterministic and random barriers for structures subjected to random processes also were computed. A brief discussion was included on the future direction of probabilistic structural analysis.

STS-65 Space Shuttle mission report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1994-01-01

The STS-65 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Redesigned Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the sixty-third flight of the Space Shuttle Program and the seventeenth flight of the Orbiter vehicle Columbia (OV-102). In addition to the Orbits the flight vehicle consisted of an ET that was designated ET-64; three SSME's that were designated as serial numbers 2019, 2030, and 2017 in positions 1, 2, and 3, respectively; and two SRB's that were designated Bl-066. The RSRM's that were installed in each SRB were designated as 360P039A for the left SRB, and 360W039 for the right SRB. The primary objective of this flight was to complete the operation of the second International Microgravity Laboratory (IML-2). The secondary objectives of this flight were to complete the operations of the Commercial Protein Crystal Growth (CPCG), Orbital Acceleration Research Experiment (OARE), and the Shuttle Amateur Radio Experiment (SAREX) II payloads. Additional secondary objectives were to meet the requirements of the Air Force Maui Optical Site (AMOS) and the Military Application Ship Tracks (MAST) payloads, which were manifested as payloads of opportunity.

Viscous flow computations for elliptical two-duct version of the SSME hot gas manifold

NASA Technical Reports Server (NTRS)

Roger, R. P.

1986-01-01

The objective of the effort was to numerically simulate viscous subsonic flow in a proposed elliptical two-duct version of the fuel side Hot Gas Manifold (HGM) for the Space Shuttle Main Engine (SSME). The numerical results were to complement both water flow and air flow experiments in the two-duct geometry performed at NASA-MSFC and Rocketdyne. The three-dimensional character of the HGM consists of two essentially different geometries. The first part of the construction is a concentric shell duct structure which channels the gases from a turbine exit into the second part comprised of two cylindrically shaped transfer ducts. The initial concentric shell portion can be further subdivided into a turnaround section and a bowl section. The turnaround duct (TAD) changes the direction of the mean flow by 180 degress from a smaller radius to a larger radius duct which discharges into the bowl. The cylindrical transfer ducts are attached to the bowl on one side thus providing a plane of symmetry midway between the two. Centerline flow distance from the TAD inlet to the transfer duct exit is approximately two feet. Details of the approach used to numerically simulate laminar or turbulent flow in the HGM geometry are presented. Computational results are presented and discussed.

International Space Station Active Thermal Control Sub-System On-Orbit Pump Performance and Reliability Using Liquid Ammonia as a Coolant

NASA Technical Reports Server (NTRS)

Morton, Richard D.; Jurick, Matthew; Roman, Ruben; Adamson, Gary; Bui, Chinh T.; Laliberte, Yvon J.

2011-01-01

The International Space Station (ISS) contains two Active Thermal Control Sub-systems (ATCS) that function by using a liquid ammonia cooling system collecting waste heat and rejecting it using radiators. These subsystems consist of a number of heat exchangers, cold plates, radiators, the Pump and Flow Control Subassembly (PFCS), and the Pump Module (PM), all of which are Orbital Replaceable Units (ORU's). The PFCS provides the motive force to circulate the ammonia coolant in the Photovoltaic Thermal Control Subsystem (PVTCS) and has been in operation since December, 2000. The Pump Module (PM) circulates liquid ammonia coolant within the External Active Thermal Control Subsystem (EATCS) cooling the ISS internal coolant (water) loops collecting waste heat and rejecting it through the ISS radiators. These PM loops have been in operation since December, 2006. This paper will discuss the original reliability analysis approach of the PFCS and Pump Module, comparing them against the current operational performance data for the ISS External Thermal Control Loops.

Evaluation of an Atmosphere Revitalization Subsystem for Deep Space Exploration Missions

NASA Technical Reports Server (NTRS)

Perry, Jay L.; Abney, Morgan B.; Conrad, Ruth E.; Frederick, Kenneth R.; Greenwood, Zachary W.; Kayatin, Matthew J.; Knox, James C.; Newton, Robert L.; Parrish, Keith J.; Takada, Kevin C.;

Power, Avionics and Software - Phase 1.0:. [Subsystem Integration Test Report

NASA Technical Reports Server (NTRS)

Ivancic, William D.; Sands, Obed S.; Bakula, Casey J.; Oldham, Daniel R.; Wright, Ted; Bradish, Martin A.; Klebau, Joseph M.

2014-01-01

This report describes Power, Avionics and Software (PAS) 1.0 subsystem integration testing and test results that occurred in August and September of 2013. This report covers the capabilities of each PAS assembly to meet integration test objectives for non-safety critical, non-flight, non-human-rated hardware and software development. This test report is the outcome of the first integration of the PAS subsystem and is meant to provide data for subsequent designs, development and testing of the future PAS subsystems. The two main objectives were to assess the ability of the PAS assemblies to exchange messages and to perform audio testing of both inbound and outbound channels. This report describes each test performed, defines the test, the data, and provides conclusions and recommendations.

The redwood project: An overview

NASA Technical Reports Server (NTRS)

Cheatham, Sam

1993-01-01

Redwood is a new generation tape subsystem now under development at StorageTek using helical scan technology. This library based storage subsystem is designed for the high performance, deep archival market. The topics are presented in viewgraph form and include the following: subsystem overview, media standards, Redwood developed tape, D3 helical recording format, Redwood cartridge, host software for Redwood libraries, and market opportunities.

Preprototype SAWD subsystem

NASA Technical Reports Server (NTRS)

Nalette, T. A.

1984-01-01

A regenerable, three man preprototype solid amine, water desorbed (SAWD) CO2 removal and concentation subsystem was designed, fabricated, and successfully acceptance tested by Hamilton Standard. The preprototype SAWD incorporates a single solid amine canister to perform the CO2 removal function, an accumulator to provide the CO2 storage and delivery function, and a microprocessor which automatically controls the subsystem sequential operation and performance. The SAWD subsystem was configured to have a CO2 removal and CO2 delivery capability at the rate of 0.12 kg/hr (0.264 lb/hr) over the relative humidity range of 35 to 70%. The controller was developed to provide fully automatic control over the relative humidity range via custom software that was generated specifically for the SAWD subsystem. The preprototype SAWD subsystem demonstrated a total of 281 hours (208) cycles of operation during ten acceptance tests that were conducted over the 3 to 70% relative humidity range. This operation was comprised of 178 hours (128 cycles) in the CO2 overboard mode and 103 hours (80 cycles) in the CO2 reduction mode. The average CO2 removal/delivery rate met or exceeded the design specification rate of 0.12 kg/hr (0.254 lb/hr) for all ten of the acceptance tests.

Position and attitude tracking control for a quadrotor UAV.

PubMed

Xiong, Jing-Jing; Zheng, En-Hui

2014-05-01

A synthesis control method is proposed to perform the position and attitude tracking control of the dynamical model of a small quadrotor unmanned aerial vehicle (UAV), where the dynamical model is underactuated, highly-coupled and nonlinear. Firstly, the dynamical model is divided into a fully actuated subsystem and an underactuated subsystem. Secondly, a controller of the fully actuated subsystem is designed through a novel robust terminal sliding mode control (TSMC) algorithm, which is utilized to guarantee all state variables converge to their desired values in short time, the convergence time is so small that the state variables are acted as time invariants in the underactuated subsystem, and, a controller of the underactuated subsystem is designed via sliding mode control (SMC), in addition, the stabilities of the subsystems are demonstrated by Lyapunov theory, respectively. Lastly, in order to demonstrate the robustness of the proposed control method, the aerodynamic forces and moments and air drag taken as external disturbances are taken into account, the obtained simulation results show that the synthesis control method has good performance in terms of position and attitude tracking when faced with external disturbances. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Bearings working group

NASA Technical Reports Server (NTRS)

1985-01-01

The service life of the Space Shuttle Main Engine (SSME) turbomachinery bearings was a predominant factor in engine durability and maintenance problems. Recent data has indicated that bearing life is about one order of magnitude lower than the goal of seven and one-half hours particularly those in the High Pressure Oxidizer Turbopump (HPOTP). Bearing technology, primarily cryogenic turbomachinery bearing technology, is expanded by exploring the life and performance effects of design changes; design concept changes; materials changes; manufacturing technique changes; and lubrication system changes. Each variation is assessed against the current bearing design in full scale cryogenic tests.

3D rocket combustor acoustics model

NASA Technical Reports Server (NTRS)

Priem, Richard J.; Breisacher, Kevin J.

1992-01-01

The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, or three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1D, 2D, and 3D assumption with regards to capturing the physical phenomena of interest and computational requirements.

SSME 3-D Turnaround Duct flow analysis - CFD predictions

NASA Technical Reports Server (NTRS)

Brankovic, Andreja; Stowers, Steven T.; Mcconnaughey, Paul

1988-01-01

CFD analysis is presently employed to obtain an improved flowfield for an individual flowpath in the case of the Space Shuttle Main Engine's High Pressure Fuel Turbopump Turn-Around Duct (TAD), which conducts the flow exiting from the gas turbines into the fuel bowl. It is demonstrated that the application of CFD to TAD flow analysis, giving attention to the duct's configuration and to the number, shape, and alignment of the diffuser struts, can enhance understanding of flow physics and result in improved duct design and performance.

Analysis of the human operator subsystems

NASA Technical Reports Server (NTRS)

Jones, Lynette A.; Hunter, Ian W.

1991-01-01

Except in low-bandwidth systems, knowledge of the human operator transfer function is essential for high-performance telerobotic systems. This information has usually been derived from detailed analyses of tracking performance, in which the human operator is considered as a complete system rather than as a summation of a number of subsystems, each of which influences the operator's output. Studies of one of these subsystems, the limb mechanics system, demonstrate that large parameter variations can occur that can have a profound effect on the stability of force-reflecting telerobot systems. An objective of this research was to decompose the performance of the human operator system in order to establish how the dynamics of each of the elements influence the operator's responses.

Waveform stimulus subsystem: An advanced technology multifunction subsystem on a card

NASA Astrophysics Data System (ADS)

Pritchard, David J.

The F-15 TISS ATE (automatic test equipment) requires subsystem-on-a-card technology to achieve the required functionality within the space constraints. The waveform stimulus subsystem (WSS), an example of this advanced technology, is considered. The WSS circuit card consists of two 40-MHz pulse generators and an 80-MHz aribtrary waveform generator. Each generator is independently programmed and is available simultaneously to the user. The implementation of this highly integrated malfunction-detection system on a card is described, and the benefits to performance and maintainability are highlighted.

Instrumentation, control and data management for the MIST (Modular Integrated Utility System) Facility

NASA Technical Reports Server (NTRS)

Celino, V. A.

1977-01-01

An appendix providing the technical data required for computerized control and/or monitoring of selected MIST subsystems is presented. Specific computerized functions to be performed are as follows: (1) Control of the MIST heating load simulator and monitoring of the diesel engine generators' cooling system; (2) Control of the MIST heating load simulator and MIST heating subsystem including the heating load simulator; and (3) Control of the MIST air conditioning load simulator subsystem and the MIST air conditioning subsystem, including cold thermal storage and condenser water flows.

MIUS Integration and Subsystem Test (MIST) data system

NASA Technical Reports Server (NTRS)

Pringle, L. M.

1977-01-01

A data system for use in testing integrated subsystems of a modular integrated utility system (MIUS) is presented. The MIUS integration and subsystem test (MIST) data system is reviewed from its conception through its checkout and operation as the controlling portion of the MIST facility. The MIST data system provides a real time monitoring and control function that allows for complete evaluation of the performance of the mechanical and electrical subsystems, as well as controls the operation of the various components of the system. In addition to the aforementioned capabilities, the MIST data system provides computerized control of test operations such that minimum manpower is necessary to set up, operate, and shut down subsystems during test periods.

STS-72 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1996-01-01

The STS-72 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-fourth flight of the Space Shuttle Program, the forty-ninth flight since the return-to-flight, and the tenth flight of the Orbiter Endeavour (OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-75; three Block I SSME's that were designated as serial numbers 2028, 2039, and 2036 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-077. The RSRM's, designated RSRM-52, were installed in each SRB and the individual RSRM's were designated as 36OW052A for the left SRB, and 36OW052B for the right SRB. Appendix A lists the sources of data, both formal and informal, that were used to prepare this report. The primary objectives of this flight were to retrieve the Japanese Space Flyer Unit (JSFU) and deploy and retrieve the Office of Aeronautics and Space Technology-Flyer (OAST-Flyer). Secondary objectives were to perform the operations of the Shuttle Solar Backscatter Ultraviolet (SSBUV/A) experiment, Shuttle Laser Altimeter (SLA)/get-Away Special (GAS) payload, Physiological and Anatomical Rodent Experiment/National Institutes of Health-Cells (STL/NIH-C) experiment, Protein Crystal Growth-Single Locker Thermal Enclosure System (PCG-STES) experiment, Commercial Protein Crystal Growth (CPCG) payload and perform two extravehicular activities (EVA's) to demonstrate International Space Station Alpha (ISSA) assembly techniques). Appendix B provides the definition of acronyms and abbreviations used throughout the report. All times during the flight are given in Greenwich mean time (GMT) and mission elapsed time (MET).

STS-63 Space Shuttle report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1995-01-01

The STS-63 Space Shuttle Program Mission Report summarizes the Payload activities and provides detailed data on the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle Main Engine (SSME) systems performance during this sixty-seventh flight of the Space Shuttle Program, the forty-second since the return to flight, and twentieth flight of the Orbiter vehicle Discovery (OV-103). In addition to the OV-103 Orbiter vehicle, the flight vehicle consisted of an ET that was designated ET-68; three SSME's that were designated 2035, 2109, and 2029 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-070. The RSRM's that were an integral part of the SRB's were designated 360Q042A for the left SRB and 360L042B for the right SRB. The STS-63 mission was planned as an 8-day duration mission with two contingency days available for weather avoidance or Orbiter contingency operations. The primary objectives of the STS-63 mission were to perform the Mir rendezvous operations, accomplish the Spacehab-3 experiments, and deploy and retrieve the Shuttle Pointed Autonomous Research Tool for Astronomy-204 (SPARTAN-204) payload. The secondary objectives were to perform the Cryogenic Systems Experiment (CSE)/Shuttle Glo-2 Experiment (GLO-2) Payload (CGP)/Orbital Debris Radar Calibration Spheres (ODERACS-2) (CGP/ODERACS-2) payload objectives, the Solid Surface Combustion Experiment (SSCE), and the Air Force Maui Optical Site Calibration Tests (AMOS). The objectives of the Mir rendezvous/flyby were to verify flight techniques, communication and navigation-aid sensor interfaces, and engineering analyses associated with Shuttle/Mir proximity operations in preparation for the STS-71 docking mission.

Roller Bearing Health Monitoring Using CPLE Frequency Analysis Method

NASA Technical Reports Server (NTRS)

Jong, Jen-Yi; Jones, Jess H.

2007-01-01

This paper describes a unique vibration signature analysis technique Coherence Phase Line Enhancer (CPLE) Frequency Analysis - for roller bearing health monitoring. Defects of roller bearing (e.g. wear, foreign debris, crack in bearing supporting structure, etc.) can cause small bearing characteristic frequency shifts due to minor changes in bearing geometry. Such frequency shifts are often too small to detect by the conventional Power Spectral Density (PSD) due to its frequency bandwidth limitation. This Coherent Phase Line Enhancer technology has been evolving over the last few years and has culminated in the introduction of a new and novel frequency spectrum which is fully described in this paper. This CPLE technology uses a "key phasor" or speed probe as a preprocessor for this analysis. With the aid of this key phasor, this CPLE technology can develop a two dimensional frequency spectrum that preserves both amplitude and phase that is not normally obtained using conventional frequency analysis. This two-dimensional frequency transformation results in several newly defined spectral functions; i. e. CPLE-PSD, CPLE-Coherence and the CPLE-Frequency. This paper uses this CPLE frequency analysis to detect subtle, low level bearing related signals in the High Pressure Fuel Pump (HPFP) of the Space Shuttle Main Engine (SSME). For many rotating machinery applications, a key phasor is an essential measurement that is used in the detection of bearing related signatures. There are times however, when a key phasor is not available; i. e. during flight of any of the SSME turbopumps or on the SSME High Pressure Oxygen Turbopump (HPOTP) where no speed probe is present. In this case, the CPLE analysis approach can still be achieved using a novel Pseudo Key Phasor (PKP) technique to reconstruct a 1/Rev PKP signal directly from external vibration measurements. This paper develops this Pseudo Key Phasor technique and applies it to the SSME vibration data.

Constellation Ground Systems Launch Availability Analysis: Enhancing Highly Reliable Launch Systems Design

NASA Technical Reports Server (NTRS)

Gernand, Jeffrey L.; Gillespie, Amanda M.; Monaghan, Mark W.; Cummings, Nicholas H.

2010-01-01

Success of the Constellation Program's lunar architecture requires successfully launching two vehicles, Ares I/Orion and Ares V/Altair, within a very limited time period. The reliability and maintainability of flight vehicles and ground systems must deliver a high probability of successfully launching the second vehicle in order to avoid wasting the on-orbit asset launched by the first vehicle. The Ground Operations Project determined which ground subsystems had the potential to affect the probability of the second launch and allocated quantitative availability requirements to these subsystems. The Ground Operations Project also developed a methodology to estimate subsystem reliability, availability, and maintainability to ensure that ground subsystems complied with allocated launch availability and maintainability requirements. The verification analysis developed quantitative estimates of subsystem availability based on design documentation, testing results, and other information. Where appropriate, actual performance history was used to calculate failure rates for legacy subsystems or comparative components that will support Constellation. The results of the verification analysis will be used to assess compliance with requirements and to highlight design or performance shortcomings for further decision making. This case study will discuss the subsystem requirements allocation process, describe the ground systems methodology for completing quantitative reliability, availability, and maintainability analysis, and present findings and observation based on analysis leading to the Ground Operations Project Preliminary Design Review milestone.

Cost-effective data storage/archival subsystem for functional PACS

NASA Astrophysics Data System (ADS)

Chen, Y. P.; Kim, Yongmin

1993-09-01

Not the least of the requirements of a workable PACS is the ability to store and archive vast amounts of information. A medium-size hospital will generate between 1 and 2 TBytes of data annually on a fully functional PACS. A high-speed image transmission network coupled with a comparably high-speed central data storage unit can make local memory and magnetic disks in the PACS workstations less critical and, in an extreme case, unnecessary. Under these circumstances, the capacity and performance of the central data storage subsystem and database is critical in determining the response time at the workstations, thus significantly affecting clinical acceptability. The central data storage subsystem not only needs to provide sufficient capacity to store about ten days worth of images (five days worth of new studies, and on the average, about one comparison study for each new study), but also supplies images to the requesting workstation in a timely fashion. The database must provide fast retrieval responses upon users' requests for images. This paper analyzes both advantages and disadvantages of multiple parallel transfer disks versus RAID disks for short-term central data storage subsystem, as well as optical disk jukebox versus digital recorder tape subsystem for long-term archive. Furthermore, an example high-performance cost-effective storage subsystem which integrates both the RAID disks and high-speed digital tape subsystem as a cost-effective PACS data storage/archival unit are presented.

ATS-6 engineering performance report. Volume 3: Telecommunications and power

NASA Technical Reports Server (NTRS)

Wales, R. O. (Editor)

1981-01-01

Functional design requirements and in-orbit operations, performance, and anomalies are discussed for (1) the communications subsystem, (2) the electrical power system, and (3) the telemetry and command subsystem. The latter includes a review of ground support. Tracking and data relay experiments and the Apollo-Soyuz test program are reviewed.

Newman Unit 1 advanced solar repowering advanced conceptual design. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1982-04-01

The Newman Unit 1 solar repowering design is a water/steam central receiver concept supplying superheated steam. The work reported is to develop a refined baseline conceptual design that has potential for construction and operation by 1986, makes use of existing solar thermal technology, and provides the best economics for this application. Trade studies performed in the design effort are described, both for the conceptual design of the overall system and for the subsystem conceptual design. System-level functional requirements, design, operation, performance, cost, safety, environmental, institutional, and regulatory considerations are described. Subsystems described include the collector, receiver, fossil energy, electrical powermore » generating, and master control subsystems, site and site facilities. The conceptual design, cost, and performance of each subsystem is discussed at length. A detailed economic analysis of the repowered unit is made to realistically assess the economics of the first repowered unit using present cost data for a limited production level for solar hardware. Finally, a development plan is given, including the design, procurement, construction, checkout, startup, performance validation, and commercial operation. (LEW)« less

Rumination and Default Mode Network Subsystems Connectivity in First-episode, Drug-Naive Young Patients with Major Depressive Disorder

PubMed Central

Zhu, Xueling; Zhu, Qiuling; Shen, Huaizhen; Liao, Weihua; Yuan, Fulai

2017-01-01

Neuroimaging evidence implicates the association between rumination and default mode network (DMN) in major depressive disorder (MDD). However, the relationship between rumination and DMN subsystems remains incompletely understood, especially in patients with MDD. Thirty-three first-episode drug-naive patients with MDD and thirty-three healthy controls (HCs) were enrolled and underwent resting-sate fMRI scanning. Functional connectivity analysis was performed based on 11 pre-defined regions of interest (ROIs) for three DMN subsystems: the midline core, dorsal medial prefrontal cortex (dMPFC) and medial temporal lobe (MTL). Compared with HCs group, patients with MDD exhibited increased within-system connectivity in the dMPFC subsystem and inter-system connectivity between the dMPFC and MTL subsystems. Decreased inter-system connectivity was identified between the midline core and dMPFC subsystem in MDD patients. Depressive rumination was positively correlated with within-system connectivity in the dMPFC subsystem (dMPFC-TempP) and with inter-system connectivity between the dMPFC and MTL subsystems (LTC-PHC). Our results suggest MDD may be characterized by abnormal DMN subsystems connectivity, which may contribute to the pathophysiology of the maladaptive self-focus in MDD patients. PMID:28225084

A fuel-efficient cruise performance model for general aviation piston engine airplanes. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Parkinson, R. C. H.

1983-01-01

A fuel-efficient cruise performance model which facilitates maximizing the specific range of General Aviation airplanes powered by spark-ignition piston engines and propellers is presented. Airplanes of fixed design only are considered. The uses and limitations of typical Pilot Operating Handbook cruise performance data, for constructing cruise performance models suitable for maximizing specific range, are first examined. These data are found to be inadequate for constructing such models. A new model of General Aviation piston-prop airplane cruise performance is then developed. This model consists of two subsystem models: the airframe-propeller-atmosphere subsystem model; and the engine-atmosphere subsystem model. The new model facilitates maximizing specific range; and by virtue of its implicity and low volume data storge requirements, appears suitable for airborne microprocessor implementation.

Relationships Between Design Characteristics of Avionics Subsystems and Training Cost, Training Difficulty, and Job Performance. Final Report, Covering Activity from 1 July 1971 Through 1 September 1972.

ERIC Educational Resources Information Center

Lintz, Larry M.; And Others

A study investigated the relationship between avionics subsystem design characteristics and training time, training cost, and job performance. A list of design variables believed to affect training and job performance was established and supplemented with personnel variables, including aptitude test scores and the amount of training and…

ASDTIC: A feedback control innovation

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Schoenfeld, A. D.

1972-01-01

The ASDTIC (Analog Signal to Discrete Time Interval Converter) control subsystem provides precise output control of high performance aerospace power supplies. The key to ASDTIC operation is that it stably controls output by sensing output energy change as well as output magnitude. The ASDTIC control subsystem and control module were developed to improve power supply performance during static and dynamic input voltage and output load variations, to reduce output voltage or current regulation due to component variations or aging, to maintain a stable feedback control with variations in the loop gain or loop time constants, and to standardize the feedback control subsystem for power conditioning equipment.

System design analyses of a rotating advanced-technology space station for the year 2025

NASA Technical Reports Server (NTRS)

Queijo, M. J.; Butterfield, A. J.; Cuddihy, W. F.; Stone, R. W.; Wrobel, J. R.; Garn, P. A.; King, C. B.

1988-01-01

Studies of an advanced technology space station configured to implement subsystem technologies projected for availability in the time period 2000 to 2025 is documented. These studies have examined the practical synergies in operational performance available through subsystem technology selection and identified the needs for technology development. Further analyses are performed on power system alternates, momentum management and stabilization, electrothermal propulsion, composite materials and structures, launch vehicle alternates, and lunar and planetary missions. Concluding remarks are made regarding the advanced technology space station concept, its intersubsystem synergies, and its system operational subsystem advanced technology development needs.

Guidance, navigation, and control subsystem for the EOS-AM spacecraft

NASA Technical Reports Server (NTRS)

Linder, David M.; Tolek, Joseph T.; Lombardo, John

1992-01-01

This paper presents the preliminary design of the Guidance, Navigation, and Control (GN&C) subsystem for the EOS-AM spacecraft and specifically focuses on the GN&C Normal Mode design. First, a brief description of the EOS-AM science mission, instruments, and system-level spacecraft design is provided. Next, an overview of the GN&C subsystem functional and performance requirements, hardware, and operating modes is presented. Then, the GN&C Normal Mode attitude determination, attitude control, and navigation systems are detailed. Finally, descriptions of the spacecraft's overall jitter performance and Safe Mode are provided.

ASDTIC - A feedback control innovation.

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Schoenfeld, A. D.

1972-01-01

The ASDTIC (analog signal to discrete time interval converter) control subsystem provides precise output control of high performance aerospace power supplies. The key to ASDTIC operation is that it stably controls output by sensing output energy change as well as output magnitude. The ASDTIC control subsystem and control module were developed to improve power supply performance during static and dynamic input voltage and output load variations, to reduce output voltage or current regulation due to component variations or aging, to maintain a stable feedback control with variations in the loop gain or loop time constants, and to standardize the feedback control subsystem for power conditioning equipment.

Subsystem design package for Solar II collector

NASA Technical Reports Server (NTRS)

1978-01-01

The requirements for the design and performance of the Solar 2 Collector Subsystem developed for use in solar heating of single family residences and mobile homes are presented. Installation drawings are included.

Appendices for the Space Applications program, 1974

NASA Technical Reports Server (NTRS)

1974-01-01

To achieve truly low cost system design with direct evolution for inorbit shuttle resupply, a modular building block approach has been adopted. The heart of the modular building block concept lies in the ability to use a common set of nonoptimized subsystems in such a way that a wide variety of missions can be flown with no detrimental impact on performance. By standardizing the mechanical configurations and electrical interfaces of the subsystem modules, and by designing each of them to be structurally and thermally independent entities, it is possible to cluster these building blocks or modules about an instrument system so as to adequately perform the mission without the need for subsystem redevelopments for each mission. This system concept offers the following capabilities: (1) the ability to launch and orbit the observatory by either the Delta, the Titan, or the space shuttle. (2) the ability to completely reconfigure the spacecraft subsystems for different launch vehicles, and (3) the ability to perform in-orbit resupply and/or emergency retrieval of the observatory.

Opto-mechanical subsystem of a 10 micrometer wavelength receiver terminal. Waveguide laser local oscillator. Servo system

NASA Technical Reports Server (NTRS)

1975-01-01

An engineering model opto-mechanical subsystem for a 10.6-micrometer laser heterodyne receiver is developed, and a CO2 waveguide local oscillator and servo electronics are provided for the receiver. Design goals are presented for the subsystems and overall package design is described. Thermal and mechanical distortion loading tests were performed and the results are included.

Alssat Development Status and Its Applications in Trade Studies

NASA Technical Reports Server (NTRS)

Yeh, H. Y. (Jannivine); Brown, Cheryl B.; Jeng, Frank F.; Lin, Chin H.; Ewert, Michael K.

2004-01-01

The development of the Advanced Life Support (ALS) Sizing Analysis Tool (ALSSAT) using Microsoft® Excel was initiated by the Crew and Thermal Systems Division (CTSD) of Johnson Space Center (JSC) in 1997 to support the ALS and Exploration Offices in Environmental Control and Life Support System (ECLSS) design and studies. It aids the user in performing detailed sizing of the ECLSS based on suggested default values or user inputs for different combinations of the ALS regenerative system technologies (Ref. 1, 2). This analysis tool will assist the user in performing ECLSS preliminary design and trade studies as well as system optimization efficiently and economically. Since ALSSAT's latest publication in ICES 2001 (Ref. 1) describing the development of ALSSAT with its Air Revitalization Subsystem (ARS), Water Management Subsystem (WMS), and Biomass Subsystem (Biomass) mass balance sheets, ALSSAT has been expanded to include mass balance and sizing models for the remaining three ALS subsystems, namely, the Solid Waste Management Subsystem (SWMS), the Food Management Subsystem (FMS), and the Thermal Control Subsystem (TCS). The external interfaces, including the Extravehicular Activities (EVA) and Human Accommodations (HA), were implemented into ALSSAT in 2002. The overall mass balance sheet, which integrates the six ALS subsystems and the external interfaces applicable to the ECLSS, was also developed. In 2003, ALSSAT was upgraded to include the consideration of redundancy and contingency options in the ECLSS, as well as more ALS regenerative technology selections. ALSSAT has been used for the Metric Calculation for FY02 and FY03 (Ref. 3). Several trade studies were conducted in 2003. The analytical results will be presented in this paper.

Design and installation package for a solar powered pump

NASA Technical Reports Server (NTRS)

1978-01-01

The design and installation procedures of a solar powered pump developed by Calmac Manufacturing Company are presented. Subsystem installation, operation and maintenance requirements, subsystem performance specifications, and detailed design drawings are included.

Headway Separation Assurance Subsystem (HSAS)

DOT National Transportation Integrated Search

1975-07-01

This report discusses the design, fabrication, test and evaluation of a Headway Separation Assurance Subsystem (HSAS) capable of reliable, failsafe performance in PRT systems. The items designed include both hardware and software packages. These pack...

An adaptive learning control system for aircraft

NASA Technical Reports Server (NTRS)

Mekel, R.; Nachmias, S.

1978-01-01

A learning control system and its utilization as a flight control system for F-8 Digital Fly-By-Wire (DFBW) research aircraft is studied. The system has the ability to adjust a gain schedule to account for changing plant characteristics and to improve its performance and the plant's performance in the course of its own operation. Three subsystems are detailed: (1) the information acquisition subsystem which identifies the plant's parameters at a given operating condition; (2) the learning algorithm subsystem which relates the identified parameters to predetermined analytical expressions describing the behavior of the parameters over a range of operating conditions; and (3) the memory and control process subsystem which consists of the collection of updated coefficients (memory) and the derived control laws. Simulation experiments indicate that the learning control system is effective in compensating for parameter variations caused by changes in flight conditions.

An automated environment for multiple spacecraft engineering subsystem mission operations

NASA Technical Reports Server (NTRS)

Bahrami, K. A.; Hioe, K.; Lai, J.; Imlay, E.; Schwuttke, U.; Hsu, E.; Mikes, S.

1990-01-01

Flight operations at the Jet Propulsion Laboratory (JPL) are now performed by teams of specialists, each team dedicated to a particular spacecraft. Certain members of each team are responsible for monitoring the performances of their respective spacecraft subsystems. Ground operations, which are very complex, are manual, labor-intensive, slow, and tedious, and therefore costly and inefficient. The challenge of the new decade is to operate a large number of spacecraft simultaneously while sharing limited human and computer resources, without compromising overall reliability. The Engineering Analysis Subsystem Environment (EASE) is an architecture that enables fewer controllers to monitor and control spacecraft engineering subsystems. A prototype of EASE has been installed in the JPL Space Flight Operations Facility for on-line testing. This article describes the underlying concept, development, testing, and benefits of the EASE prototype.

Viking Orbiter 1975 articulation control subsystem design analysis

NASA Technical Reports Server (NTRS)

Horiuchi, H. H.; Vallas, L. J.

1973-01-01

The articulation control subsystem, developed for the Viking Orbiter 1975 spacecraft, is a digital, multiplexed, closed-loop servo system used to control the pointing and positioning of the science scan platform and the high-gain communication antenna, and to position the solar-energy controller louver blades for the thermal control of the propellant tanks. The development, design, and anlaysis of the subsystem is preliminary. The subsystem consists of a block-redundant control electronics multiplexed among eight control actuators. Each electronics block is capable of operating either individually or simultaneously with the second block. This provides the subsystem the capability of simultaneous two-actuator control or a single actuator control with the second block in a stand-by redundant mode. The result of the preliminary design and analysis indicates that the subsystem will perform satisfactorily in the Viking Orbiter 1975 mission. Some of the parameter values used, particularly those in the subsystem dynamics and the error estimates, are preliminary and the results will be updated as more accurate parameter values become available.

Informational correlation between two parties of a quantum system: spin-1/2 chains

NASA Astrophysics Data System (ADS)

Zenchuk, A. I.

2014-12-01

We introduce the informational correlation between two interacting quantum subsystems and of a quantum system as the number of arbitrary parameters of a unitary transformation (locally performed on the subsystem ) which may be detected in the subsystem by the local measurements. This quantity indicates whether the state of the subsystem may be effected by means of the unitary transformation applied to the subsystem . Emphasize that in general. The informational correlations in systems with tensor product initial states are studied in more details. In particular, it is shown that the informational correlation may be changed by the local unitary transformations of the subsystem . However, there is some non-reducible part of which may not be decreased by any unitary transformation of the subsystem at a fixed time instant . Two examples of the informational correlations between two parties of the four-node spin-1/2 chain with mixed initial states are studied. The long chains with a single initially excited spin (the pure initial state) are considered as well.

Advanced Extravehicular Protective System (AEPS) study

NASA Technical Reports Server (NTRS)

Williams, J. L.; Webbon, B. W.; Copeland, R. J.

1972-01-01

A summary is presented of Advanced Extravehicular Protective Systems (AEPS) for the future missions beyond Skylab in earth orbit, on the lunar surface, and on the Martian surface. The study concentrated on the origination of regenerable life support concepts for use in portable extravehicular protective systems, and included evaluation and comparison with expendable systems, and selection of life support subsystems. The study was conducted in two phases. In the first phase, subsystem concepts for performing life support functions in AEPS which are regenerable or partially regenerable were originated, and in addition, expendable subsystems were considered. Parametric data for each subsystem concept were evolved including subsystem weight and volume, power requirement, thermal control requirement; base regeneration equipment weight and volume, requirement. The second phase involved an evaluation of the impact of safety considerations involving redundant and/or backup systems on the selection of the regenerable life support subsystems. In addition, the impact of the space shuttle program on regenerable life support subsystem development was investigated.

Engine Data Interpretation System (EDIS), phase 2

NASA Technical Reports Server (NTRS)

Cost, Thomas L.; Hofmann, Martin O.

1991-01-01

A prototype of an expert system was developed which applies qualitative constraint-based reasoning to the task of post-test analysis of data resulting from a rocket engine firing. Data anomalies are detected and corresponding faults are diagnosed. Engine behavior is reconstructed using measured data and knowledge about engine behavior. Knowledge about common faults guides but does not restrict the search for the best explanation in terms of hypothesized faults. The system contains domain knowledge about the behavior of common rocket engine components and was configured for use with the Space Shuttle Main Engine (SSME). A graphical user interface allows an expert user to intimately interact with the system during diagnosis. The system was applied to data taken during actual SSME tests where data anomalies were observed.

Heat flux measurement in SSME turbine blade tester

NASA Astrophysics Data System (ADS)

Liebert, Curt H.

1990-11-01

Surface heat flux values were measured in the turbine blade thermal cycling tester located at NASA-Marshall. This is the first time heat flux has been measured in a space shuttle main engine turbopump environment. Plots of transient and quasi-steady state heat flux data over a range of about 0 to 15 MW/sq m are presented. Data were obtained with a miniature heat flux gage device developed at NASA-Lewis. The results from these tests are being incorporated into turbine design models. Also, these gages are being considered for airfoil surface heat flux measurement on turbine vanes mounted in SSME turbopump test bed engine nozzles at Marshall. Heat flux effects that might be observed on degraded vanes are discussed.

Heat flux measurement in SSME turbine blade tester

NASA Astrophysics Data System (ADS)

Liebert, Curt H.

Surface heat flux values were measured in the turbine blade thermal cycling tester located at NASA-Marshall. This is the first time heat flux has been measured in a space shuttle main engine turbopump environment. Plots of transient and quasi-steady state heat flux data over a range of about 0 to 15 MW/sq m are presented. Data were obtained with a miniature heat flux gage device developed at NASA-Lewis. The results from these tests are being incorporated into turbine design models. Also, these gages are being considered for airfoil surface heat flux measurement on turbine vanes mounted in SSME turbopump test bed engine nozzles at Marshall. Heat flux effects that might be observed on degraded vanes are discussed.

Incipient failure detection (IFD) of SSME ball bearings

NASA Technical Reports Server (NTRS)

1982-01-01

Because of the immense noise background during the operation of a large engine such as the SSME, the relatively low level unique ball bearing signatures were often buried by the overall machine signal. As a result, the most commonly used bearing failure detection technique, pattern recognition using power spectral density (PSD) constructed from the extracted bearing signals, is rendered useless. Data enhancement techniques were carried out by using a HP5451C Fourier Analyzer. The signal was preprocessed by a Digital Audio Crop. DAC-1024I noise cancelling filter in order to estimate the desired signal corrupted by the backgound noise. Reference levels of good bearings were established. Any deviation of bearing signals from these reference levels indicate the incipient bearing failures.

Artificial intelligence techniques for ground test monitoring of rocket engines

NASA Technical Reports Server (NTRS)

Ali, Moonis; Gupta, U. K.

1990-01-01

An expert system is being developed which can detect anomalies in Space Shuttle Main Engine (SSME) sensor data significantly earlier than the redline algorithm currently in use. The training of such an expert system focuses on two approaches which are based on low frequency and high frequency analyses of sensor data. Both approaches are being tested on data from SSME tests and their results compared with the findings of NASA and Rocketdyne experts. Prototype implementations have detected the presence of anomalies earlier than the redline algorithms that are in use currently. It therefore appears that these approaches have the potential of detecting anomalies early eneough to shut down the engine or take other corrective action before severe damage to the engine occurs.

Lightning testing at the subsystem level

NASA Technical Reports Server (NTRS)

Luteran, Frank

1991-01-01

Testing at the subsystem or black box level for lightning hardness is required if system hardness is to be assured at the system level. The often applied philosophy of lighting testing only at the system level leads to extensive end of the line design changes which result in excessive costs and time delays. In order to perform testing at the subsystem level two important factors must be defined to make the testing simulation meaningful. The first factor is the definition of the test stimulus appropriate to the subsystem level. Application of system level stimulations to the subsystem level usually leads to significant overdesign of the subsystem which is not necessary and may impair normal subsystem performance. The second factor is the availability of test equipment needed to provide the subsystem level lightning stimulation. Equipment for testing at this level should be portable or at least movable to enable efficient testing in a design laboratory environment. Large fixed test installations for system level tests are not readily available for use by the design engineers at the subsystem level and usually require special operating skills. The two factors, stimulation level and test equipment availability, must be evaluated together in order to produce a practical, workable test standard. The neglect or subordination of either factor will guarantee failure in generating the standard. It is not unusual to hear that test standards or specifications are waived because a specified stimulation level cannot be accomplished by in-house or independent test facilities. Determination of subsystem lightning simulation level requires a knowledge and evaluation of field coupling modes, peak and median levels of voltages and currents, bandwidths, and repetition rates. Practical limitations on test systems may require tradeoffs in lightning stimulation parameters in order to build practical test equipment. Peak power levels that can be generated at specified bandwidths with standard electrical components must be considered in the design and costing of the test system. Stimulation tests equipment and test methods are closely related and must be considered a test system for lightning simulation. A non-perfect specification that can be reliably and repeatedly applied at the subsystem test level is more desirable than a perfect specification that cannot be applied at all.

Determination of Uncertainties for the New SSME Model

NASA Technical Reports Server (NTRS)

Coleman, Hugh W.; Hawk, Clark W.

1996-01-01

This report discusses the uncertainty analysis performed in support of a new test analysis and performance prediction model for the Space Shuttle Main Engine. The new model utilizes uncertainty estimates for experimental data and for the analytical model to obtain the most plausible operating condition for the engine system. This report discusses the development of the data sets and uncertainty estimates to be used in the development of the new model. It also presents the application of uncertainty analysis to analytical models and the uncertainty analysis for the conservation of mass and energy balance relations is presented. A new methodology for the assessment of the uncertainty associated with linear regressions is presented.

Development of new materials for turbopump bearings

NASA Technical Reports Server (NTRS)

Maurer, R. E.; Pallini, R. A.

1985-01-01

The life requirement for the angular contact ball bearings in the Space Shuttle Main Engine (SSME) high pressure oxygen turbopump (HPOTP) is 7.5 hours. In actual operation, significantly shorter service life was experienced. The objective is to identify bearing materials and/or materials processing techniques offering signficant potential for extending HPOTP bearing performance life. Interactive thermomechanical analysis of the HPOTP bearing-shaft system was performed with the SHABERTH computer program. Bearing fatigue life, ball-race contact stress, heat generation rate, bulk ring temperatures and circumferential stress in the inner rings were quantified as functions of radial load, thrust load and ball-race contact friction. Criteria established from the output of this analysis are being used for material candidate selection.

Composite load spectra for select space propulsion structural components

NASA Technical Reports Server (NTRS)

Newell, J. F.; Ho, H. W.; Kurth, R. E.

1991-01-01

The work performed to develop composite load spectra (CLS) for the Space Shuttle Main Engine (SSME) using probabilistic methods. The three methods were implemented to be the engine system influence model. RASCAL was chosen to be the principal method as most component load models were implemented with the method. Validation of RASCAL was performed. High accuracy comparable to the Monte Carlo method can be obtained if a large enough bin size is used. Generic probabilistic models were developed and implemented for load calculations using the probabilistic methods discussed above. Each engine mission, either a real fighter or a test, has three mission phases: the engine start transient phase, the steady state phase, and the engine cut off transient phase. Power level and engine operating inlet conditions change during a mission. The load calculation module provides the steady-state and quasi-steady state calculation procedures with duty-cycle-data option. The quasi-steady state procedure is for engine transient phase calculations. In addition, a few generic probabilistic load models were also developed for specific conditions. These include the fixed transient spike model, the poison arrival transient spike model, and the rare event model. These generic probabilistic load models provide sufficient latitude for simulating loads with specific conditions. For SSME components, turbine blades, transfer ducts, LOX post, and the high pressure oxidizer turbopump (HPOTP) discharge duct were selected for application of the CLS program. They include static pressure loads and dynamic pressure loads for all four components, centrifugal force for the turbine blade, temperatures of thermal loads for all four components, and structural vibration loads for the ducts and LOX posts.

CFD Analysis of Thermal Control System Using NX Thermal and Flow

NASA Technical Reports Server (NTRS)

Fortier, C. R.; Harris, M. F. (Editor); McConnell, S. (Editor)

2014-01-01

The Thermal Control Subsystem (TCS) is a key part of the Advanced Plant Habitat (APH) for the International Space Station (ISS). The purpose of this subsystem is to provide thermal control, mainly cooling, to the other APH subsystems. One of these subsystems, the Environmental Control Subsystem (ECS), controls the temperature and humidity of the growth chamber (GC) air to optimize the growth of plants in the habitat. The TCS provides thermal control to the ECS with three cold plates, which use Thermoelectric Coolers (TECs) to heat or cool water as needed to control the air temperature in the ECS system. In order to optimize the TCS design, pressure drop and heat transfer analyses were needed. The analysis for this system was performed in Siemens NX Thermal/Flow software (Version 8.5). NX Thermal/Flow has the ability to perform 1D or 3D flow solutions. The 1D flow solver can be used to represent simple geometries, such as pipes and tubes. The 1D flow method also has the ability to simulate either fluid only or fluid and wall regions. The 3D flow solver is similar to other Computational Fluid Dynamic (CFD) software. TCS performance was analyzed using both the 1D and 3D solvers. Each method produced different results, which will be evaluated and discussed.

Apollo experience report: Development of the extravehicular mobility unit

NASA Technical Reports Server (NTRS)

Lutz, C. C.; Stutesman, H. L.; Carson, M. A.; Mcbarron, J. W., II

1975-01-01

The development and performance history of the Apollo extravehicular mobility unit and its major subsystems is described. The three major subsystems, the pressure garment assembly, the portable life-support system, and the oxygen purge system, are defined and described in detail as is the evolutionary process that culminated in each major subsystem component. Descriptions of ground-support equipment and the qualification testing process for component hardware are also presented.

A Power Conversion Concept for the Jupiter Icy Moons Orbiter

NASA Technical Reports Server (NTRS)

Mason, Lee S.

2003-01-01

The Jupiter Icy Moons Orbiter (JIMO) mission is currently under study by the Office of Space Science under the Project Prometheus Program. JIMO is examining the use of Nuclear Electric Propulsion (NEP) to carry scientific payloads to three Jovian moons. A potential power system concept includes dual 100 kWe Brayton converters, a deployable pumped loop heat rejection subsystem, and a 400 Vac Power Management and Distribution (PMAD) bus. Many trades were performed in aniving at this candidate power system concept. System-level studies examined design and off-design operating modes, determined startup requirements, evaluated subsystem redundancy options, and quantified the mass and radiator area of reactor power systems from 20 to 200 kWe. In the Brayton converter subsystem, studies were performed to investigate converter packaging options, and assess the induced torque effects on spacecraft dynamics due to rotating machinery. In the heat rejection subsystem, design trades were conducted on heat transport approaches, material and fluid options, and deployed radiator geometries. In the PMAD subsystem, the overall electrical architecture was defined and trade studies examined distribution approaches, voltage levels, and cabling options.

HIRDLS Cryocooler Subsystem on-orbit Performance

NASA Astrophysics Data System (ADS)

Lock, J.; Stack, R.; Glaister, D. S.; Gully, W.

2006-04-01

This paper describes the HIRDLS (High Resolution Dynamic Limb Sounder) Cryocooler Subsystem (CSS) and its on-orbit flight performance. The HIRDLS Instrument was launched on July 15, 2004 as part of the NASA GSFC EOS Aura platform. Ball Aerospace provided the CSS, which includes the long life Stirling cryocooler (cooling at 59 K), cold plumbing to connect the cooler to the instrument Detector Subsystem, an ambient radiator to reject the cooler dissipation, and a vacuum enclosure system that enabled bench top ground testing. As of August 20, 2005, the cryocooler has over 9,000 hours of continuous operation with performance that exceeds requirements. Of note is that the CSS has experienced virtually no change in performance, including no indication of external contamination related degradation that has been evident on several other cryocooler systems in space flights. This steady performance can be attributed to the multi-layer insulation (MLI) based insulation design, which will be described in the paper.

Crew Launch Vehicle (CLV) Upper Stage Configuration Selection Process

NASA Technical Reports Server (NTRS)

Davis, Daniel J.; Coook, Jerry R.

2006-01-01

The Crew Launch Vehicle (CLV), a key component of NASA's blueprint for the next generation of spacecraft to take humans back to the moon, is being designed and built by engineers at NASA s Marshall Space Flight Center (MSFC). The vehicle s design is based on the results of NASA's 2005 Exploration Systems Architecture Study (ESAS), which called for development of a crew-launch system to reduce the gap between Shuttle retirement and Crew Exploration Vehicle (CEV) Initial Operating Capability, identification of key technologies required to enable and significantly enhance these reference exploration systems, and a reprioritization of near- and far-term technology investments. The Upper Stage Element (USE) of the CLV is a clean-sheet approach that is being designed and developed in-house, with element management at MSFC. The USE concept is a self-supporting cylindrical structure, approximately 115' long and 216" in diameter, consisting of the following subsystems: Primary Structures (LOX Tank, LH2 Tank, Intertank, Thrust Structure, Spacecraft Payload Adaptor, Interstage, Forward and Aft Skirts), Secondary Structures (Systems Tunnel), Avionics and Software, Main Propulsion System, Reaction Control System, Thrust Vector Control, Auxiliary Power Unit, and Hydraulic Systems. The ESAS originally recommended a CEV to be launched atop a four-segment Space Shuttle Main Engine (SSME) CLV, utilizing an RS-25 engine-powered upper stage. However, Agency decisions to utilize fewer CLV development steps to lunar missions, reduce the overall risk for the lunar program, and provide a more balanced engine production rate requirement prompted engineers to switch to a five-segment design with a single Saturn-derived J-2X engine. This approach provides for single upper stage engine development for the CLV and an Earth Departure Stage, single Reusable Solid Rocket Booster (RSRB) development for the CLV and a Cargo Launch Vehicle, and single core SSME development. While the RSRB design has changed since the CLV Project's inception, the USE design has remained essentially a clean-sheet approach. Although a clean-sheet upper stage design inherently carries more risk than a modified design, it does offer many advantages: a design for increased reliability; built-in extensibility to allow for commonality/growth without major redesign; and incorporation of state-of-the-art materials, hardware, and design, fabrication, and test techniques and processes to facilitate a potentially better, more reliable system. Because consideration was given in the ESAS to both clean-sheet and modified USE designs, this paper will highlight the advantages and disadvantages of both approaches and provide a detailed discussion of trades/selections made that led to the final upper stage configuration.

Central receiver solar thermal power system, Phase 1. CDRL item 2. Pilot plant preliminary design report. Volume VI. Electrical power generation and master control subsystems and balance of plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hallet, Jr., R. W.; Gervais, R. L.

1977-10-01

The requirements, performance, and subsystem configuration for both the Commercial and Pilot Plant electrical power generation subsystems (EPGS) and balance of plants are presented. The EPGS for both the Commercial Plant and Pilot Plant make use of conventional, proven equipment consistent with good power plant design practices in order to minimize risk and maximize reliability. The basic EPGS cycle selected is a regenerative cycle that uses a single automatic admission, condensing, tandem-compound double-flow turbine. Specifications, performance data, drawings, and schematics are included. (WHK)

The Role of Structural Dynamics and Testing in the Shuttle Flowliner Crack Investigation

NASA Technical Reports Server (NTRS)

Frady, Gregory P.

2005-01-01

During a normal inspection of the main propulsion system at Kennedy Space Center, small cracks were noticed near a slotted region of a gimbal joint flowliner located just upstream from one of the Space Shuttle Main Engines (SSME). These small cracks sparked an investigation of the entire Space Shuttle fleet main propulsion feedlines. The investigation was initiated to determine the cause of the small cracks and a repair method that would be needed to return the Shuttle fleet back to operation safely. The cracks were found to be initiated by structural resonance caused by flow fluctuations from the SSME low pressure fuel turbopump interacting with the flowliner. The pump induced backward traveling wakes that excited the liner and duct acoustics which also caused the liner to vibrate in complex mode shapes. The investigation involved an extensive effort by a team of engineers from the NASA civil servant and contractor workforce with the goal to characterize the root cause of the cracking behavior of the fuel side gimbal joint flowliners. In addition to working to identify the root cause, a parallel path was taken to characterize the material properties and fatigue capabilities of the liner material such that the life of the liners could be ascertained. As the characterization of the material and the most probable cause matured, the combination of the two with pump speed restrictions provided a means to return the Shuttle to flight in a safe manner. This paper traces the flowliner investigation results with respect to the structural dynamics analysis, component level testing and hot-fire flow testing on a static testbed. The paper will address the unique aspects of a very complex problem involving backflow from a high performance pump that has never been characterized nor understood to such detail. In addition, the paper will briefly address the flow phenomena that excited the liners, the unique structural dynamic modal characteristics and the variability of SSME operation which has ultimately ensured the safe and reliable operation of the shuttle main engines for each flight.

Human resources management and firm performance: The differential role of managerial affective and continuance commitment.

PubMed

Gong, Yaping; Law, Kenneth S; Chang, Song; Xin, Katherine R

2009-01-01

In this study, the authors developed a dual-concern (i.e., maintenance and performance) model of human resources (HR) management. The authors identified commonly examined HR practices that apply to the middle manager level and classified them into the maintenance- and performance-oriented HR subsystems. The authors found support for the 2-factor model on the basis of responses from 2,148 managers from 463 firms operating in China. Regression results indicate that the performance-oriented HR subsystems had a positive relationship with firm performance and that the relationship was mediated by middle managers' affective commitment to the firm. The maintenance-oriented HR subsystems had a positive relationship with middle managers' continuance commitment but not with their affective commitment and firm performance. This study contributes to the understanding of how HR practices relate to firm performance and offers an improved test of the argument that valuable and firm-specific HR provide a source of competitive advantage. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Airlock caution and warning system

NASA Technical Reports Server (NTRS)

Mayfield, W. J.; Cork, L. Z.; Malchow, R. G.; Hornback, G. L.

1972-01-01

Caution and warning system, used to monitor performance and warn of hazards or out-of-limit conditions on space vehicles, may have application to aircraft and railway transit systems. System consists of caution and warning subsystem and emergency subsystem.

OAO-C end-of-mission power subsystem engineering evaluation

NASA Technical Reports Server (NTRS)

Tasevoli, M.

1982-01-01

The battery performance on both Orbiting Astronomical Observatory missions was excellent. The end-of-mission power subsystem tests on the battery and the solar arrays provides a real-time degradation analysis for these two components.

On-orbit experience with the HEAO attitude control subsystem

NASA Technical Reports Server (NTRS)

Hoffman, D. P.; Berkery, E. A.

1978-01-01

The first satellite (HEAO-1) in the High Energy Astronomy Observatory Program series was launched successfully on Aug. 12, 1977. To date it has completed over nine months of orbital operation in a science data gathering mode. During this period all attitude control modes have been exercised and all primary mission objectives have been achieved. This paper highlights the characteristics of the attitude control subsystem design and compares the predicted performance with the actual flight operations experience. Environmental disturbance modeling, component hardware/software characteristics, and overall attitude control performance are reviewed and are found to compare very well with the prelaunch analytical predictions. Brief comments are also included regarding the operations aspects of the attitude control subsystem. The experience in this regard demonstrates the effectiveness of the design flexibility afforded by the presence of a general purpose digital processor in the subsystem flight hardware implementation.

2nd & 3rd Generation Vehicle Subsystems

NASA Technical Reports Server (NTRS)

2000-01-01

This paper contains viewgraph presentation on the "2nd & 3rd Generation Vehicle Subsystems" project. The objective behind this project is to design, develop and test advanced avionics, power systems, power control and distribution components and subsystems for insertion into a highly reliable and low-cost system for a Reusable Launch Vehicles (RLV). The project is divided into two sections: 3rd Generation Vehicle Subsystems and 2nd Generation Vehicle Subsystems. The following topics are discussed under the first section, 3rd Generation Vehicle Subsystems: supporting the NASA RLV program; high-performance guidance & control adaptation for future RLVs; Evolvable Hardware (EHW) for 3rd generation avionics description; Scaleable, Fault-tolerant Intelligent Network or X(trans)ducers (SFINIX); advance electric actuation devices and subsystem technology; hybrid power sources and regeneration technology for electric actuators; and intelligent internal thermal control. Topics discussed in the 2nd Generation Vehicle Subsystems program include: design, development and test of a robust, low-maintenance avionics with no active cooling requirements and autonomous rendezvous and docking systems; design and development of a low maintenance, high reliability, intelligent power systems (fuel cells and battery); and design of a low cost, low maintenance high horsepower actuation systems (actuators).

The mariner 9 power subsystem design and flight performance

NASA Technical Reports Server (NTRS)

Josephs, R. H.

1973-01-01

The design and flight performance of the Mariner Mars 1971 power subsystem are presented. Mariner 9 was the first spacecraft to orbit another planet, and some of the power management techniques employed to support an orbital mission far from earth with marginal sunlight for its photovoltaic-battery power source are described. The performance of its nickel-cadmium battery during repetitive sun occultation phases of the mission, and the results of unique tests in flight to assess the performance capability of its solar array are reported.

Integrated Advanced Microwave Sounding Unit-A (AMSU-A). Performance Verification Report: METSAT AMSU-A2 Antenna Drive Subsystem, P/N 1331200-2, S/N 106

NASA Technical Reports Server (NTRS)

Higgins, T.

1998-01-01

An antenna drive subsystem test was performed on the METSAT AMSU-A2 S/N 106 instrument. The objective of the test was to demonstrate compliance with applicable paragraphs of AMSU-A specifications S480-80. Tests were conducted at both the subassembly and instrument level.

Viking orbiter system primary mission

NASA Technical Reports Server (NTRS)

Goudy, J. R.

1977-01-01

An overview of Viking Orbiter (VO) system and subsystem performances during the primary mission (the time period from VO-1 launch on August 20, 1975, through November 15, 1976) is presented. Brief descriptions, key design requirements, pertinent historical information, unique applications or situations, and predicted versus actual performances are included for all VO-1 and VO-2 subsystems, both individually and as an integrated system.

Transitioning from conceptual design to construction performance specification

NASA Astrophysics Data System (ADS)

Jeffers, Paul; Warner, Mark; Craig, Simon; Hubbard, Robert; Marshall, Heather

2012-09-01

On successful completion of a conceptual design review by a funding agency or customer, there is a transition phase before construction contracts can be placed. The nature of this transition phase depends on the Project's approach to construction and the particular subsystem being considered. There are generically two approaches; project retention of design authority and issuance of build to print contracts, or issuance of subsystem performance specifications with controlled interfaces. This paper relates to the latter where a proof of concept (conceptual or reference design) is translated into performance based sub-system specifications for competitive tender. This translation is not a straightforward process and there are a number of different issues to consider in the process. This paper deals with primarily the Telescope mount and Enclosure subsystems. The main subjects considered in this paper are: • Typical status of design at Conceptual Design Review compared with the desired status of Specifications and Interface Control Documents at Request for Quotation. • Options for capture and tracking of system requirements flow down from science / operating requirements and sub-system requirements, and functional requirements derived from reference design. • Requirements that may come specifically from the contracting approach. • Methods for effective use of reference design work without compromising a performance based specification. • Management of project team's expectation relating to design. • Effects on cost estimates from reference design to actual. This paper is based on experience and lessons learned through this process on both the VISTA and the ATST projects.

Space tug point design study. Volume 3: Design definition. Part 1: Propulsion and mechanical, avionics, thermal control and electrical power subsystems

NASA Technical Reports Server (NTRS)

1973-01-01

A study was conducted to determine the configuration and performance of a space tug. Details of the space tug systems are presented to include: (1) propulsion systems, (2) avionics, (3) thermal control, and (4) electric power subsystems. The data generated include engineering drawings, schematics, subsystem operation, and component description. Various options investigated and the rational for the point design selection are analyzed.

Display management subsystem, version 1: A user's eye view

NASA Technical Reports Server (NTRS)

Parker, Dolores

1986-01-01

The structure and application functions of the Display Management Subsystem (DMS) are described. The DMS, a subsystem of the Transportable Applications Executive (TAE), was designed to provide a device-independent interface for an image processing and display environment. The system is callable by C and FORTRAN applications, portable to accommodate different image analysis terminals, and easily expandable to meet local needs. Generic applications are also available for performing many image processing tasks.

A large-scale photonic node architecture that utilizes interconnected OXC subsystems.

PubMed

Iwai, Yuto; Hasegawa, Hiroshi; Sato, Ken-ichi

2013-01-14

We propose a novel photonic node architecture that is composed of interconnected small-scale optical cross-connect subsystems. We also developed an efficient dynamic network control algorithm that complies with a restriction on the number of intra-node fibers used for subsystem interconnection. Numerical evaluations verify that the proposed architecture offers almost the same performance as the equivalent single large-scale cross-connect switch, while enabling substantial hardware scale reductions.

The Sortie-Generation Model System. Volume 5. Maintenance Subsystem

DTIC Science & Technology

1981-09-01

Compuger RoanutI f and moidel 11, Computer operatinS system 17, Proorammino largualviso IS. Numlier of .ugic proltsm Hoewl -3 CSCobol 600 stuscomentm...THE SORTIE-GENERATION MODEL SYSTEM OC’ VOLUME V MAINTENANCE SUBSYSTEM September 1981 Robert S. Greenberg 05$ Prepared pursuant to Department of...Generation Model System Volume V Maintenance Subsystem 6. PERFORMING ORG. REPORT NUMBER LMI Task- L102 7. AUTHOR(a) 8. CONTRACT OR GRANT NUMBER(a

Apollo experience report: Guidance and control systems. Lunar module stabilization and control system

NASA Technical Reports Server (NTRS)

Shelton, D. H.

1975-01-01

A brief functional description of the Apollo lunar module stabilization and control subsystem is presented. Subsystem requirements definition, design, development, test results, and flight experiences are discussed. Detailed discussions are presented of problems encountered and the resulting corrective actions taken during the course of assembly-level testing, integrated vehicle checkout and test, and mission operations. Although the main experiences described are problem oriented, the subsystem has performed satisfactorily in flight.

Vibroacoustic optimization using a statistical energy analysis model

NASA Astrophysics Data System (ADS)

Culla, Antonio; D`Ambrogio, Walter; Fregolent, Annalisa; Milana, Silvia

2016-08-01

In this paper, an optimization technique for medium-high frequency dynamic problems based on Statistical Energy Analysis (SEA) method is presented. Using a SEA model, the subsystem energies are controlled by internal loss factors (ILF) and coupling loss factors (CLF), which in turn depend on the physical parameters of the subsystems. A preliminary sensitivity analysis of subsystem energy to CLF's is performed to select CLF's that are most effective on subsystem energies. Since the injected power depends not only on the external loads but on the physical parameters of the subsystems as well, it must be taken into account under certain conditions. This is accomplished in the optimization procedure, where approximate relationships between CLF's, injected power and physical parameters are derived. The approach is applied on a typical aeronautical structure: the cabin of a helicopter.

System impacts of solar dynamic and growth power systems on space station

NASA Technical Reports Server (NTRS)

Farmer, J. T.; Cuddihy, W. F.; Lovelace, U. M.; Badi, D. M.

1986-01-01

Concepts for the 1990's space station envision an initial operational capability with electrical power output requirements of approximately 75 kW and growth power requirements in the range of 300 kW over a period of a few years. Photovoltaic and solar dynamic power generation techniques are contenders for supplying this power to the space station. A study was performed to identify growth power subsystem impacts on other space station subsystems. Subsystem interactions that might suggest early design changes for the space station were emphasized. Quantitative analyses of the effects of power subsystem mass and projected area on space station controllability and reboost requirements were conducted for a range of growth station configurations. Impacts on space station structural dynamics as a function of power subsystem growth were also considered.

The Mariner Venus Mercury flight data subsystem.

NASA Technical Reports Server (NTRS)

Whitehead, P. B.

1972-01-01

The flight data subsystem (FDS) discussed handles both the engineering and scientific measurements performed on the MVM'73. It formats the data into serial data streams, and sends it to the modulation/demodulation subsystem for transmission to earth or to the data storage subsystem for storage on a digital tape recorder. The FDS is controlled by serial digital words, called coded commands, received from the central computer sequencer of from the ground via the modulation/demodulation subsystem. The eight major blocks of the FDS are: power converter, timing and control, engineering data, memory, memory input/output and control, nonimaging data, imaging data, and data output. The FDS incorporates some 4000 components, weighs 17 kg, and uses 35 W of power. General data on the mission and spacecraft are given.

Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 3: Experimental System Descriptions. [development and testing of a solar thermal power plant

NASA Technical Reports Server (NTRS)

Holl, R. J.

1979-01-01

The design and development of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system consists of five subsystems: the collector, power conversion, energy transport, energy storage, and the plant control subsystem. The collector subsystem consists of concentrator, receiver, and tower assemblies. The energy transport subsystem uses a mixture of salts with a low melting temperature to transport thermal energy. A steam generator drives a steam Rankine cycle turbine which drives an electrical generator to produce electricity. Thermal and stress analysis tests are performed on each subsystem in order to determine the operational reliability, the minimum risk of failure, and the maintenance and repair characteristics.

STS-69 Space Shuttle Mission Report

NASA Technical Reports Server (NTRS)

Fricke, Robert W., Jr.

1995-01-01

The STS-69 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-first flight of the Space Shuttle Program, the forty-sixth flight since the return-to-flight, and the ninth flight of the Orbiter Endeavour(OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-72; three SSME's that were designated as serial numbers 2035, 2109, and 2029 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-074. The RSRMS, designated RSRM-44, were installed in each SRB and the individual RSRM's were designated as 36OL048A for the left SRB, and 36OW048B for the right SRB. The primary objectives of this flight were to perform the operations necessary to fulfill the requirments of Wake Shield Facility (WSF) and SPARTAN-201. The secondary objectives were to perform the operation of the International Extreme Ultraviolet Hitchhiker (IEH-1), the Capillary Pumped Loop-2/GAS Bridge Assembly (CAPL-2/GBA), Thermal Energy Storage (TES), Auroral Photography Experiment-B (APE-B) and the Extravehicular Activity (EVA) Development Flight Test 02 (EDFT-02), the Biological Research in Canister (BRIC) payload, the Commercial Generic Bioprocessing Apparatus (CGBA) payload, the Electrolysis Performance Improvement Concept Study (EPICS) payload, the Space Tissue Loss, National Institute of Health-Cells (STL/NIH-CS) payload, and the Commercial Middeck Instrumentation Technology Associates Experiment (CMIX). Appendix A lists the sources of data, both formal and informal, that were used to prepare this report. Appendix B provides the definition of acronyms and abbreviations used throughout the report. All times during the flight are given in Greenwich mean time (GMT) and mission elapsed time (MET).

Novel operation and control of an electric vehicle aluminum/air battery system

NASA Astrophysics Data System (ADS)

Zhang, Xin; Yang, Shao Hua; Knickle, Harold

The objective of this paper is to create a method to size battery subsystems for an electric vehicle to optimize battery performance. Optimization of performance includes minimizing corrosion by operating at a constant current density. These subsystems will allow for easy mechanical recharging. A proper choice of battery subsystem will allow for longer battery life, greater range and performance. For longer life, the current density and reaction rate should be nearly constant. The control method requires control of power by controlling electrolyte flow in battery sub modules. As power is increased more sub modules come on line and more electrolyte is needed. Solenoid valves open in a sequence to provide the required power. Corrosion is limited because there is no electrolyte in the modules not being used.

A User's Guide for the Spacecraft Fire Safety Facility

NASA Technical Reports Server (NTRS)

Goldmeer, Jeffrey S.

2000-01-01

The Spacecraft Fire Safety Facility (SFSF) is a test facility that can be flown on NASA's reduced gravity aircraft to perform various types of combustion experiments under a variety of experimental conditions. To date, this facility has flown numerous times on the aircraft and has been used to perform experiments ranging from an examination of the effects transient depressurization on combustion, to ignition and flame spread. A list of pubfications/presentations based on experiments performed in the SFSF is included in the reference section. This facility consists of five main subsystems: combustion chamber, sample holders, gas flow system, imaging system, and the data acquisition/control system. Each of these subsystems will be reviewed in more detail. These subsystems provide the experiment operator with the ability to monitor and/or control numerous experimental parameters.

OAO-3 end of mission power subsystem evaluation

NASA Technical Reports Server (NTRS)

Tasevoli, M.

1982-01-01

End of mission tests were performed on the OAO-3 power subsystem in three component areas: solar array, nickel-cadmium batteries and the On-Board Processor (OBP) power boost operation. Solar array evaluation consisted of analyzing array performance characteristics and comparing them to earlier flight data. Measured solar array degradation of 14.1 to 17.7% after 8 1/3 years is in good agreement with theortical radiation damage losses. Battery discharge characteristics were compared to results of laboratory life cycle tests performed on similar cells. Comparison of cell voltage profils reveals close correlation and confirms the validity of real time life cycle simulation. The successful operation of the system in the OBP/power boost regulation mode demonstrates the excellent life, reliability and greater system utilization of power subsystems using maximum power trackers.

Static Feed Water Electrolysis Subsystem Testing and Component Development

NASA Technical Reports Server (NTRS)

Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

1983-01-01

A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

Performance evaluation of Platform Data ManagementSystem under various degrees of protocol implementation

NASA Technical Reports Server (NTRS)

Arozullah, Mohammed

1991-01-01

The Platform Data Management System (DMS) collects Housekeeping (H/K), Payload (P/L) Engineering, and Payload Science data from various subsystems and payloads on the platform for transmission to the ground through the downlink via TDRSS. The DMS also distributes command data received from the ground to various subsystems and payloads. In addition, DMS distributes timing and safemode data. The function of collection and distribution of various types of data is performed by the Command and Data Handling (C&DH) subsystem of DMS. The C&DH subsystem uses for this purpose a number of data buses namely, Housekeeping, Payload Engineering, Payload Science, and Time and Safemode buses. Out of these buses, the H/K, P/L Engineering, and P/L Science buses are planned to be implemented by using MIL-STD 1553 bus. Most of the period covered was spent in developing a queue theoretic model of the 1553 Bus as used in the DMS. The aim is to use this model to test the performance and suitability of the 1553 Bus to the DMS under a number of alternative design scenarios.

Sensor control of robot arc welding

NASA Technical Reports Server (NTRS)

Sias, F. R., Jr.

1985-01-01

A basic problem in the application of robots for welding which is how to guide a torch along a weld seam using sensory information was studied. Improvement of the quality and consistency of certain Gas Tungsten Arc welds on the Space Shuttle Main Engine (SSME) that are too complex geometrically for conventional automation and therefore are done by hand was examined. The particular problems associated with space shuttle main egnine (SSME) manufacturing and weld-seam tracking with an emphasis on computer vision methods were analyzed. Special interface software for the MINC computr are developed which will allow it to be used both as a test system to check out the robot interface software and later as a development tool for further investigation of sensory systems to be incorporated in welding procedures.

OPAD status report - Investigation of SSME component erosion

NASA Astrophysics Data System (ADS)

Powers, W. T.; Cooper, A. E.; Wallace, T. L.

1992-04-01

Significant erosion of preburner faceplates was observed during recent SSME test firings at the NASA Technology Test Bed (TTB). The OPAD instrumentation acquired exhaust-plume spectral data during each test which indicate the occurrence of metallic species consistent with faceplate component composition. A qualitative analysis of the spectral data was conducted to evaluate the state of the engine versus time for each test according to the nominal conditions of TTB firing number 17 and number 18. In general the analyses indicate abnormal erosion levels at or near startup. Subsequent to the initial erosion event, signal levels tend to decrease towards nominal baseline values. These findings, in conjunction with post-test engine inspections, suggest that in cases under study, the erosion may not have been catastrophic to the immediate operation of the engine.

Space Shuttle Main Engine (SSME) Evolution

NASA Technical Reports Server (NTRS)

Worlund, Len A.; Hastings, J. H.; McCool, Alex (Technical Monitor)

2001-01-01

The SSME when developed in the 1970's was a technological leap in space launch propulsion system design. The engine has safely supported the space shuttle for the last two decades and will be required for at least another decade to support human space flight to the international space station. This paper discusses the continued improvements and maturing of the system to its current state and future considerations for its critical role in the nations space program. Discussed are the initiatives of the late 1980's, which lead to three major upgrades through the 1990's. The current capabilities of the propulsion system are defined in the areas of highest programmatic importance: ascent risk, in-flight abort thrust, reusability, and operability. Future initiatives for improved shuttle safety, the paramount priority of the Space Shuttle program are discussed.

The shuttle main engine: A first look

NASA Technical Reports Server (NTRS)

Schreur, Barbara

1996-01-01

Anyone entering the Space Shuttle Main Engine (SSME) team attends a two week course to become familiar with the design and workings of the engine. This course provides intensive coverage of the individual hardware items and their functions. Some individuals, particularly those involved with software maintenance and development, have felt overwhelmed by this volume of material and their lack of a logical framework in which to place it. To provide this logical framework, it was decided that a brief self-taught introduction to the overall operation of the SSME should be designed. To aid the people or new team members with an interest in the software, this new course should also explain the structure and functioning of the controller and its software. This paper presents a description of this presentation.

Development of life prediction capabilities for liquid propellant rocket engines. Post-fire diagnostic system for the SSME system architecture study

NASA Technical Reports Server (NTRS)

Gage, Mark; Dehoff, Ronald

1991-01-01

This system architecture task (1) analyzed the current process used to make an assessment of engine and component health after each test or flight firing of an SSME, (2) developed an approach and a specific set of objectives and requirements for automated diagnostics during post fire health assessment, and (3) listed and described the software applications required to implement this system. The diagnostic system described is a distributed system with a database management system to store diagnostic information and test data, a CAE package for visual data analysis and preparation of plots of hot-fire data, a set of procedural applications for routine anomaly detection, and an expert system for the advanced anomaly detection and evaluation.

Experimental Flow Models for SSME Flowfield Characterization

NASA Technical Reports Server (NTRS)

Abel, L. C.; Ramsey, P. E.

1989-01-01

Full scale flow models with extensive instrumentation were designed and manufactured to provide data necessary for flow field characterization in rocket engines of the Space Shuttle Main Engine (SSME) type. These models include accurate flow path geometries from the pre-burner outlet through the throat of the main combustion chamber. The turbines are simulated with static models designed to provide the correct pressure drop and swirl for specific power levels. The correct turbopump-hot gas manifold interfaces were designed into the flow models to permit parametric/integration studies for new turbine designs. These experimental flow models provide a vehicle for understanding the fluid dynamics associated with specific engine issues and also fill the more general need for establishing a more detailed fluid dynamic base to support development and verification of advanced math models.

SSME main combustion chamber life prediction

NASA Technical Reports Server (NTRS)

Cook, R. T.; Fryk, E. E.; Newell, J. F.

1983-01-01

Typically, low cycle fatigue life is a function of the cyclic strain range, the material properties, and the operating temperature. The reusable life is normally defined by the number of strain cycles that can be accrued before severe material degradation occurs. Reusable life is normally signified by the initiation or propagation of surface cracks. Hot-fire testing of channel wall combustors has shown significant mid-channel wall thinning or deformation during accrued cyclic testing. This phenomenon is termed cyclic-creep and appears to be significantly accelerated at elevated surface temperatures. This failure mode was analytically modelled. The cyclic life of the baseline SSME-MCC based on measured calorimeter heat transfer data, and the life sensitivity of local hot spots caused by injector effects were determined. Four life enhanced designs were assessed.

Evaluation of outer race tilt and lubrication on ball wear and SSME bearing life reductions

NASA Technical Reports Server (NTRS)

Kannel, J. W.; Merriman, T. L.; Stockwell, R. D.; Dufrane, K. F.

1983-01-01

Several aspects of the SSME bearing operation were evaluated. The possibility of elastohydrodynamics (EHD) lubrication with a cryogenic fluid was analyzed. Films as thick as .61 microns were predicted with one theory which may be thick enough to provide hydrodynamic support. The film formation, however, is heavily dependent on good surface finish and a low bulk bearing temperature. Bearing dynamics to determine if the radial stiffness of a bearing which are dependent on bearing misalignment were analyzed. Four ball tests were conducted at several environmental conditions from an LN2 bath to 426 C in air. Surface coatings and ball materials are evaluated. Severe wear and high friction are measured for all ball materials except when the balls have surface lubricant coatings.

Enhancements to the SSME transfer function modeling code

NASA Technical Reports Server (NTRS)

Irwin, R. Dennis; Mitchell, Jerrel R.; Bartholomew, David L.; Glenn, Russell D.

1995-01-01

This report details the results of a one year effort by Ohio University to apply the transfer function modeling and analysis tools developed under NASA Grant NAG8-167 (Irwin, 1992), (Bartholomew, 1992) to attempt the generation of Space Shuttle Main Engine High Pressure Turbopump transfer functions from time domain data. In addition, new enhancements to the transfer function modeling codes which enhance the code functionality are presented, along with some ideas for improved modeling methods and future work. Section 2 contains a review of the analytical background used to generate transfer functions with the SSME transfer function modeling software. Section 2.1 presents the 'ratio method' developed for obtaining models of systems that are subject to single unmeasured excitation sources and have two or more measured output signals. Since most of the models developed during the investigation use the Eigensystem Realization Algorithm (ERA) for model generation, Section 2.2 presents an introduction of ERA, and Section 2.3 describes how it can be used to model spectral quantities. Section 2.4 details the Residue Identification Algorithm (RID) including the use of Constrained Least Squares (CLS) and Total Least Squares (TLS). Most of this information can be found in the report (and is repeated for convenience). Section 3 chronicles the effort of applying the SSME transfer function modeling codes to the a51p394.dat and a51p1294.dat time data files to generate transfer functions from the unmeasured input to the 129.4 degree sensor output. Included are transfer function modeling attempts using five methods. The first method is a direct application of the SSME codes to the data files and the second method uses the underlying trends in the spectral density estimates to form transfer function models with less clustering of poles and zeros than the models obtained by the direct method. In the third approach, the time data is low pass filtered prior to the modeling process in an effort to filter out high frequency characteristics. The fourth method removes the presumed system excitation and its harmonics in order to investigate the effects of the excitation on the modeling process. The fifth method is an attempt to apply constrained RID to obtain better transfer functions through more accurate modeling over certain frequency ranges. Section 4 presents some new C main files which were created to round out the functionality of the existing SSME transfer function modeling code. It is now possible to go from time data to transfer function models using only the C codes; it is not necessary to rely on external software. The new C main files and instructions for their use are included. Section 5 presents current and future enhancements to the XPLOT graphics program which was delivered with the initial software. Several new features which have been added to the program are detailed in the first part of this section. The remainder of Section 5 then lists some possible features which may be added in the future. Section 6 contains the conclusion section of this report. Section 6.1 is an overview of the work including a summary and observations relating to finding transfer functions with the SSME code. Section 6.2 contains information relating to future work on the project.

System comprising interchangeable electronic controllers and corresponding methods

NASA Technical Reports Server (NTRS)

Steele, Glen F. (Inventor); Salazar, George A. (Inventor)

2009-01-01

A system comprising an interchangeable electronic controller is provided with programming that allows the controller to adapt a behavior that is dependent upon the particular type of function performed by a system or subsystem component. The system reconfigures the controller when the controller is moved from one group of subsystem components to another. A plurality of application programs are provided by a server from which the application program for a particular electronic controller is selected. The selection is based on criteria such as a subsystem component group identifier that identifies the particular type of function associated with the system or subsystem group of components.

Automation based on knowledge modeling theory and its applications in engine diagnostic systems using Space Shuttle Main Engine vibrational data. M.S. Thesis

NASA Technical Reports Server (NTRS)

Kim, Jonnathan H.

1995-01-01

Humans can perform many complicated tasks without explicit rules. This inherent and advantageous capability becomes a hurdle when a task is to be automated. Modern computers and numerical calculations require explicit rules and discrete numerical values. In order to bridge the gap between human knowledge and automating tools, a knowledge model is proposed. Knowledge modeling techniques are discussed and utilized to automate a labor and time intensive task of detecting anomalous bearing wear patterns in the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP).

The 3D rocket combustor acoustics model

NASA Technical Reports Server (NTRS)

Priem, Richard J.; Breisacher, Kevin J.

1992-01-01

The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, and three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1-D, 2-D, and 3-D assumptions with regards to capturing the physical phenomena of interest and computational requirements.

Space Shuttle Project

NASA Image and Video Library

1996-12-16

A NASA scientist displays Space Shuttle Main Engine (SSME) turbine component which underwent air flow tests at Marshall's Structures and Dynamics Lab. Such studies could improve efficiency of aircraft engines, and lower operational costs.