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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 757 records · Page 42
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

The NASA/industry Design Analysis Methods for Vibrations (DAMVIBS) program: McDonnell-Douglas Helicopter Company achievements

This paper presents a summary of some of the work performed by McDonnell Douglas Helicopter Company under NASA Langley-sponsored rotorcraft structural dynamics program known as DAMVIBS (Design Analysis Methods for VIBrationS). A set of guidelines which is applicable to dynamic modeling, analysis, testing, and correlation of both helicopter airframes and a large variety of structural finite element models is presented. Utilization of these guidelines and the key features of their applications to vibration modeling of helicopter airframes are discussed. Correlation studies with the test data, together with the development and applications of a set of efficient finite element model checkout procedures, are demonstrated on a large helicopter airframe finite element model. Finally, the lessons learned and the benefits resulting from this program are summarized.

Toossi, Mostafa↗
NASA NTRS1991

Intelligent systems technology infrastructure for integrated systems

Significant advances have occurred during the last decade in intelligent systems technologies (a.k.a. knowledge-based systems, KBS) including research, feasibility demonstrations, and technology implementations in operational environments. Evaluation and simulation data obtained to date in real-time operational environments suggest that cost-effective utilization of intelligent systems technologies can be realized for Automated Rendezvous and Capture applications. The successful implementation of these technologies involve a complex system infrastructure integrating the requirements of transportation, vehicle checkout and health management, and communication systems without compromise to systems reliability and performance. The resources that must be invoked to accomplish these tasks include remote ground operations and control, built-in system fault management and control, and intelligent robotics. To ensure long-term evolution and integration of new validated technologies over the lifetime of the vehicle, system interfaces must also be addressed and integrated into the overall system interface requirements. An approach for defining and evaluating the system infrastructures including the testbed currently being used to support the on-going evaluations for the evolutionary Space Station Freedom Data Management System is presented and discussed. Intelligent system technologies discussed include artificial intelligence (real-time replanning and scheduling), high performance computational elements (parallel processors, photonic processors, and neural networks), real-time fault management and control, and system software development tools for rapid prototyping capabilities.

Lum, Henry, Jr.↗
NASA NTRS1993

Robustness

Robustness is a buzz word common to all newly proposed space systems design as well as many new commercial products. The image that one conjures up when the word appears is a 'Paul Bunyon' (lumberjack design), strong and hearty; healthy with margins in all aspects of the design. In actuality, robustness is much broader in scope than margins, including such factors as simplicity, redundancy, desensitization to parameter variations, control of parameter variations (environments flucation), and operational approaches. These must be traded with concepts, materials, and fabrication approaches against the criteria of performance, cost, and reliability. This includes manufacturing, assembly, processing, checkout, and operations. The design engineer or project chief is faced with finding ways and means to inculcate robustness into an operational design. First, however, be sure he understands the definition and goals of robustness. This paper will deal with these issues as well as the need for the requirement for robustness.

Ryan, R.↗
NASA NTRS1992

Research and technology goals and objectives for Integrated Vehicle Health Management (IVHM)

Integrated Vehicle Health Management (IVHM) is defined herein as the capability to efficiently perform checkout, testing, and monitoring of space transportation vehicles, subsystems, and components before, during, and after operational This includes the ability to perform timely status determination, diagnostics, and prognostics. IVHM must support fault-tolerant response including system/subsystem reconfiguration to prevent catastrophic failures; and IVHM must support the planning and scheduling of post-operational maintenance. The purpose of this document is to establish the rationale for IVHM and IVHM research and technology planning, and to develop technical goals and objectives. This document is prepared to provide a broad overview of IVHM for technology and advanced development activities and, more specifically, to provide a planning reference from an avionics viewpoint under the OAST Transportation Technology Program Strategic Plan.

Source record↗
NASA NTRS1993

Integrated oxygen recovery system

Life Systems has conceptualized an innovative Integrated Oxygen Recovery System (IORS) applicable to advanced mission air revitalization. The IORS provides the capability to electrochemically generate metabolic oxygen (O2) and recover O2 from the space habitat atmosphere via a carbon dioxide (CO2) reduction process within a single assembly. To achieve this capability, the IORS utilizes a Solid Metal Cathode (SMC) water electrolysis unit that simultaneously serves as the Sabatier CO2 reduction reactor. The IORS enables two major life support systems currently baselined in closed loop air revitalization systems to be combined into one smaller, less complex system. This concept reduces fluidic and electrical interface requirements and eliminates a hydrogen (H2) interface. Life Systems is performing an evaluation of the IORS process directed at demonstrating performance and quantifying key physical characteristics including power, weight, and volume. The results of the checkout, shakedown, and initial parametric tests are summarized.

Lee, M. Gene↗
NASA NTRS1992

TCMS operations and maintenance philosophy

The purpose is to describe the basic philosophies of operating and maintaining the Test, Control, and Monitor System (TCMS) equipment. TCMS is a complex and sophisticated checkout system. Operations and maintenance processes developed to support it will be based upon current experience, but will be focused on the specific needs of TCMS in support of Space Station Freedom Program (SSFP) and related activities. An overview of the operations and maintenance goals and philosophies are presented. The assumptions, roles and responsibilities, concepts and interfaces for operation, on-line maintenance, off-line support, and Operations and Maintenance (O&M) personnel training on all TCMS equipment located at KSC are described.

Buehler, David P.↗
NASA NTRS1993

Test, Control and Monitor System (TCMS) operations plan

The purpose is to provide a clear understanding of the Test, Control and Monitor System (TCMS) operating environment and to describe the method of operations for TCMS. TCMS is a complex and sophisticated checkout system focused on support of the Space Station Freedom Program (SSFP) and related activities. An understanding of the TCMS operating environment is provided and operational responsibilities are defined. NASA and the Payload Ground Operations Contractor (PGOC) will use it as a guide to manage the operation of the TCMS computer systems and associated networks and workstations. All TCMS operational functions are examined. Other plans and detailed operating procedures relating to an individual operational function are referenced within this plan. This plan augments existing Technical Support Management Directives (TSMD's), Standard Practices, and other management documentation which will be followed where applicable.

Macfarlane, C. K.↗
NASA NTRS1990

An evolutionary construction facility for Space Station Freedom

Viewgraphs and discussion on an evolutionary construction facility for Space Station Freedom are presented. Space Station Freedom (SSF) will support permanent human presence in space and has the potential to enable scientific and exploratory endeavors unequalled in history. With larger and more ambitious spacecraft being developed, it will serve as a site for construction, checkout, and deployment. A facility attached to SSF is required to develop and demonstrate the techniques that will enable on-orbit construction of future large spacecraft. Examples of attached scientific experiments that currently envision in-space construction and that are discussed are: Solar X-ray Pinhole Occulter Facility, Astromag, and X-ray Large Array. Examples of large assemblable spacecraft which are discussed are: Large Deployable Reflector (LDR), Geostationary Platforms, and interplanetary vehicles.

Gates, Richard M.↗
NASA NTRS1992

757 Fly-By-Wire Demonstrator Flight Test

The Boeing Company modified a production 757-200 to emulate the 777 fly-by-wire control laws in order to evaluate the operation and performance of the 777 FBW flight control laws in flight. Following installation and checkout of the FBW system, testing began in March, 1992. Flight testing is currently planned to continue through August, 1992. The conventional 757 longitudinal flight control system is retained but controlled by only the captain’s column. The fly-by-wire system is evaluated by the pilot in the first officer’s seat and the safety pilot function is conducted from the captain’s seat. The flight test FBW longitudinal system is a 2-channel flight control system. The first officer’s column drives the current 757 left and right flight control computers (autopilots) which are modified to act as FBW computers. These FBW computers, which emulate the 777-200 FBW control laws, drive their respective autopilot actuators to control the airplane pitch axis. Directional FBW control laws arc emulated in the existing 757 yaw dampers, with corresponding modifications to the normal 757 directional control system. This paper presents a summary of the airplane FBW modifications and the flight test program to evaluate/validate the 777 FBW flight control laws.

Flight Testing↗
NASA NTRS1992

Expert systems for automated maintenance of a Mars oxygen production system

Application of expert system concepts to a breadboard Mars oxygen processor unit have been studied and tested. The research was directed toward developing the methodology required to enable autonomous operation and control of these simple chemical processors at Mars. Failure detection and isolation was the key area of concern, and schemes using forward chaining, backward chaining, knowledge-based expert systems, and rule-based expert systems were examined. Tests and simulations were conducted that investigated self-health checkout, emergency shutdown, and fault detection, in addition to normal control activities. A dynamic system model was developed using the Bond-Graph technique. The dynamic model agreed well with tests involving sudden reductions in throughput. However, nonlinear effects were observed during tests that incorporated step function increases in flow variables. Computer simulations and experiments have demonstrated the feasibility of expert systems utilizing rule-based diagnosis and decision-making algorithms.

Huang, Jen-Kuang↗
NASA NTRS1992

Initial accomplishments of the Environmental Control and Life Support System (ECLSS) atmosphere revitalization (AR) predevelopment operational system test (POST) for the Space Station Freedom (SSF)

Initial results of the integrated AR POST conducted by Boeing at Marshall Space Flight Center in 1992 are presented. The three baselined ECLSS Man Tended Capability AR assemblies were integrated and operated in a closed door chamber in which the internal atmosphere was monitored. The test provides a prerequisite checkout of the AR subsystem in preparation for longer duration tests in which the AR subsystem will be integrated with the Water Recovery Management subsystem. The integrated AR POST will serve as an early test bed to evaluate the integration of the space station ECLSS AR subsystem during design maturation.

Dunn, Kevin H.↗
NASA NTRS1993

Extreme Ultraviolet Explorer observations of the RS Canum Venaticorum systems AR Lacertae and II Pegasi

We report observations of two RS CVn systems, II Peg and AR Lac, which were calibration targets during the in-orbit checkout phase of the Extreme Ultraviolet Explorer (EUVE). We have determined count rates, and, based on these count rates, preliminary emission measure analyses have been done. The Lexan/boron band count rates were 0.0849 +/- 0.0023 counts/s for AR Lac and 0.218 +/- 0.031 counts/s for II Peg during its quiescent state. Temperatures and emission measures derived from the EUVE data are consistent with previously published values. We also report a flare seen during the II Peg observations which has characteristics similar to previously observed flares on II Peg. During the flare the Lexan/boron count rate increased by at least a factor of 2.5, and the minimum total duration was about 34,000 s (about 9.4 hr).

Petterer, R. J.↗
NASA NTRS1991

NASA CSTI Earth-to-orbit propulsion R/T program overview

The topics presented are covered in viewgraph form. The programmatic objectives are to develop and validate technology, design tools, and methodologies needed for the development of a new generation of lower cost, operationally-efficient, long-life, highly reliable ETO propulsion systems. The technical objectives are: (1) high quality, low cost, inspectable manufacturing; (2) safe shutdown to fault tolerance operations for safety; (3) condition monitoring diagnostics for maintainability; (4) automatic servicing and checkout for ground operations; (5) max commensurate with life for performance; and full flow, combined cycle for advanced cycles.

Moses, James L.↗
NASA NTRS1977

Construction bidding cost of KSC's space shuttle facilities

The bidding cost of the major Space Transportation System facilities constructed under the responsibility of the John F. Kennedy Space Center (KSC) is described and listed. These facilities and Ground Support Equipment (GSE) are necessary for the receiving, assembly, testing, and checkout of the Space Shuttle for launch and landing missions at KSC. The Shuttle launch configuration consists of the Orbiter, the External Tank, and the Solid Rocket Boosters (SRB). The reusable Orbiter and SRB's is the major factor in the program that will result in lowering space travel costs. The new facilities are the Landing Facility; Orbiter Processing Facility; Orbiter Approach and Landing Test Facility (Dryden Test Center, California); Orbiter Mating Devices; Sound Suppression Water System; and Emergency Power System for LC-39. Also, a major factor was to use as much Apollo facilities and hardware as possible to reduce the facilities cost. The alterations to existing Apollo facilities are the VAB modifications; Mobile Launcher Platforms; Launch Complex 39 Pads A and B (which includes a new concept - the Rotary Service Structure), which was featured in ENR, 3 Feb. 1977, 'Hinged Space Truss will Support Shuttle Cargo Room'; Launch Control Center mods; External Tank and SRB Processing and Storage; Fluid Test Complex mods; O&C Spacelab mods; Shuttle mods for Parachute Facility; SRB Recovery and Disassembly Facility at Hangar 'AF'; and an interesting GSE item - the SRB Dewatering Nozzle Plug Sets (Remote Controlled Submarine System) used to inspect and acquire for reuse of SRB's.

Brown, Joseph Andrew↗
NASA NTRS1990

Servicing capability for the evolutionary Space Station

Since the beginning of the Space Station Freedom (SSF) program the concept of on-orbit servicing of user hardware has been an integral part of the program implementation. The user servicing system architecture has been divided into a baseline and a growth phase. The baseline system consists of the following hardware elements that will support user servicing - flight telerobotic servicer, crew and equipment translation aid, crew intravehicular and extravehicular servicing support, logistics supply system, mobile servicing center, and the special purpose dextrous manipulator. The growth phase incorporates a customer servicing facility (CSF), a station-based orbital maneuvering vehicle and an orbital spacecraft consumables resupply system. The requirements for user servicing were derived from the necessity to service attached payloads, free flyers and coorbiting platforms. These requirements include: orbital replacement units (ORU) and instrument changeout, National Space Transportation System cargo bay loading and unloading, contamination control and monitoring, thermal protection, payload berthing, storage, access to SSF distributed systems, functional checkout, and fluid replenishment. The baseline user servicing capabilities accommodate ORU and instrument changeout. However, this service is limited to attached payloads, either in situ or at a locally adjacent site. The growth phase satisfies all identified user servicing requirements by expanding servicing capabilities to include complex servicing tasks for attached payloads, free-flyers and coorbiting platforms at a dedicated, protected Servicing site. To provide a smooth evolution of user servicing the SSF interfaces that are necessary to accommodate the growth phase have been identified. The interface requirements on SSF have been greatly simplified by accommodating the growth servicing support elements within the CSF. This results in a single SSF interface: SSF to the CSF.

Thomas, Edward F.↗
NASA NTRS1990

On-orbit assembly/servicing task definition study

The OEXP vehicles being envisioned to carry out the Presidential space goals of a lunar outpost and human exploration of Mars will require on-orbit assembly, refurbishment, checkout, and launch. The On-orbit Assembly/Servicing Task Definition Study applies the space vehicle processing experience and procedures archives resident at NASA's Kennedy Space Center (KSC) to determine the task flows, and resources/facilities necessary to process the OEXP vehicles at Space Station Freedom (SSF). This data base is examined to find the closest analogies to OEXP vehicle components and assembly/refurbishment tasks. Transition tables are generated to provide traceability from KSC hardware processing experience to analogous on-orbit processing of the OEXP vehicles. Iterations in which the task flows are broken down into realistic extravehicular activity (EVA) primitive subtasks and times, and to apply automation and robotic technology to reduce crew risks and minimize EVA time, will enhance the value and accuracy of the predicted flows. These processing scenarios and the resulting resource/facility requirements are used to determine impacts of SSF, resulting in change requests to SSF requirements for provision of 'hooks and scars' to evolve the assembly complete Space Station into a transportation node. Study results to date include assembly analysis of the Martin Marietta Phobos Gateway Vehicle, refurbishment analysis of the Martin Marietta Lunar Evolution Piloted and Cargo Vehicles, and assembly analysis of the Boeing Mars Evolution Vehicle. The results of this study will be accumulated into the vehicle processing operations data base for subsequent modeling, life cycle cost, vehicle growth, and SSF impact analysis.

Vargo, Rick↗
NASA NTRS1990

Autonomous control

KSC has been developing the Knowledge-Based Autonomous Test Engineer (KATE), which is a tool for performing automated monitoring, diagnosis, and control of electromechanical devices. KATE employs artificial intelligence computing techniques to perform these functions. The KATE system consists of a generic shell and a knowledge base. The KATE shell is the portion of the system which performs the monitoring, diagnosis, and control functions. It is generic in the sense that it is application independent. This means that the monitoring activity, for instance, will be performed with the same algorithms regardless of the particular physical device being used. The knowledge base is the portion of the system which contains specific functional and behavorial information about the physical device KATE is working with. Work is nearing completion on a project at KSC to interface a Texas Instruments Explorer running a LISP version of KATE with a Generic Checkout System (GCS) test-bed to control a physical simulation of a shuttle tanking system (humorously called the Red Wagon because of its color and mobility). The Autonomous Control System (ACS) project supplements and extends the KATE/GCS project by adding three other major activities. The activities include: porting KATE from the Texas Instruments Explorer machine to an Intel 80386-based UNIX workstation in the LISP language; rewriting KATE as necessary to run on the same 80386 workstation but in the Ada language; and investigating software and techniques to translate ANSI Standard Common LISP to Mil Standard Ada. Primary goals of this task are as follows: (1) establish the advantages of using expert systems to provide intelligent autonomous software for Space Station Freedom applications; (2) determine the feasibility of using Ada as the run-time environment for model-based expert systems; (3) provide insight into the advantages and disadvantagesof using LISP or Ada in the run-time environment for expert systems; and (4) compare the performance of the 80386 processor to a symbolic processor as a delivery vehicle for expert systems.

Brown, Barbara↗
NASA NTRS1993

In-space assembly-servicing requirements

A method for developing the requirements for in-space assembly, servicing, and checkout of the proposed Mars space transfer vehicles is discussed. Required in-space operations and functions are identified in relation to various Earth to Orbit (ETO) vehicles by looking at the manifesting options of baseline Mars Space Transfer Vehicles (STV). Each operation is then reduced to a minimum complexity state resulting in a set of operational primitive functions. These primitive functions are used to assess the tradeoffs between robotic, telerobotic, and EVA operations. The study demonstrates that the complexity of the in-space operations remains stable with ETO vehicle size, and therefore the functions, and ultimately the infrastructure required to support proposed missions, are relatively unaffected by varying the ETO vehicle size within the range considered for this study.

Cockrell, Charles E.↗