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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 919 records · Page 51

All sources NASA NTRS DOE OSTI

NASA NTRS1981

A Module Experimental Process System Development Unit (MEPSDU)

The purpose of this program is to demonstrate the technical readiness of a cost effective process sequence that has the potential for the production of flat plate photovoltaic modules which met the price goal in 1986 of $.70 or less per watt peak. Program efforts included: preliminary design review, preliminary cell fabrication using the proposed process sequence, verification of sandblasting back cleanup, study of resist parameters, evaluation of pull strength of the proposed metallization, measurement of contact resistance of Electroless Ni contacts, optimization of process parameter, design of the MEPSDU module, identification and testing of insulator tapes, development of a lamination process sequence, identification, discussions, demonstrations and visits with candidate equipment vendors, evaluation of proposals for tabbing and stringing machine.

Source record↗

NASA NTRS1975

Drive-train dynamics technology - State-of-the-art and design of a test facility for advanced development

A program for the development and verification of drive-train dynamic technology is described along with its basis and the results expected from it. A central feature of this program is a drive-train test facility designed for the testing and development of advanced drive-train components, including shaft systems, dampers, and couplings. Previous efforts in designing flexible dynamic drive-train systems are reviewed, and the present state of the art is briefly summarized. The design of the test facility is discussed with major attention given to the formulation of the test-rig concept, dynamic scaling of model shafts, and the specification of design parameters. Specific efforts envisioned for the test facility are briefly noted, including evaluations of supercritical test shafts, stability thresholds for various sources and types of instabilities that can exist in shaft systems, effects of structural flexibility on the dynamic performance of dampers, and methods for vibration control in two-level and three-level flexible shaft systems.

Badgley, R. H.↗

NASA NTRS1979

An autonomous payload controller for the Space Shuttle

The Autonomous Payload Control (APC) system discussed in the present paper was designed on the basis of such criteria as minimal cost of implementation, minimal space required in the flight-deck area, simple operation with verification of the results, minimal additional weight, minimal impact on Orbiter design, and minimal impact on Orbiter payload integration. In its present configuration, the APC provides a means for the Orbiter crew to control as many as 31 autononous payloads. The avionics and human engineering aspects of the system are discussed.

Hudgins, J. I.↗

NASA NTRS2023

On-Board Deployment Event Verification for GOES-R Spacecraft

As is common with many spacecraft designs, the GOES-R vehicles require a series of deployment events to transition from the launch configuration to the operational configuration. Rather than implementing additional sensors to verify various deployments, the GOES-R program developed an alternate approach that uses existing gyro rate sensing. The approach includes two pieces: the first is a new onboard shock detection capability to confirm initiation of individual deployment events, and the second is a ground-based dynamics verification step to confirm completion of deployment events. We first present the algorithm that detects shock events for various deployment devices along with the parameter tuning performed during ground tests. We then show inflight performance of the shock detection algorithm. While shock detection is useful for observing initiation of deployment events, completion of some deployment events cannot be determined by shock detection alone. For these events, such as solar panel latch-up and deployable boom extension, the program developed dynamics models for the deployment transient responses. High-rate gyro data were recorded for these events, which allow the ground team to verify that the appendages were fully deployed. We show the predictive models for these events and corresponding flight results.

GeoXO↗

NASA NTRS2008

Fan Acoustic Issues in the NASA Space Flight Experience

Emphasis needs to be placed on choosing quiet fans compatible with systems design and specifications that control spec levels: a) Sound power; b) Choose quiet fan or plan to quiet it, early in program; c) Plan early verification that fan source allocations are met. Airborne noise: a) System design should function/play together with fans used (flow passages, restrictions, bends, expansions & contractions, and acoustics) vs. fan speed understood (nominal, worst case, & unplanned variances); b) Fan inlets treated, as required; c) Fan Outlets treated, as required; d) Ducted system inlets are outlets designed for acoustic compliance compatibility & designed so some late required modifications can be made without significant impacts. Structure Borne Noise: a) Structure borne noise dealt with as part of fan package or installation; b) Duct attachments and lines isolated. Case Radiated Noise: - Treatment added as much as possible to fan package (see example).

Allen, Christopher S.↗

NASA NTRS2001

Aerospace Nickel-cadmium Cell Verification

During the early years of satellites, NASA successfully flew "NASA-Standard" nickel-cadmium (Ni-Cd) cells manufactured by GE/Gates/SAFF on a variety of spacecraft. In 1992 a NASA Battery Review Board determined that the strategy of a NASA Standard Cell and Battery Specification and the accompanying NASA control of a standard manufacturing control document (MCD) for Ni-Cd cells and batteries was unwarranted. As a result of that determination, standards were abandoned and the use of cells other than the NASA Standard was required. In order to gain insight into the performance and characteristics of the various aerospace Ni-Cd products available, tasks were initiated within the NASA Aerospace Flight Battery Systems Program that involved the procurement and testing of representative aerospace Ni-Cd cell designs. A standard set of test conditions was established in order to provide similar information about the products from various vendors. The objective of this testing was to provide independent verification of representative commercial flight cells available in the marketplace today. This paper will provide a summary of the verification tests run on cells from various manufacturers: Sanyo 35 Ampere-hour (Ali) standard and 35 Ali advanced Ni-Cd cells, SAFr 50 Ah Ni-Cd cells and Eagle-Picher 21 Ali Magnum and 21 Ali Super Ni-CdTM cells from Eagle-Picher were put through a full evaluation. A limited number of 18 and 55 Ali cells from Acme Electric were also tested to provide an initial evaluation of the Acme aerospace cell designs. Additionally, 35 Ali aerospace design Ni-MH cells from Sanyo were evaluated under the standard conditions established for this program. Ile test program is essentially complete. The cell design parameters, the verification test plan and the details of the test result will be discussed.

Manzo, Michelle A.↗

NASA NTRS1983

Development of heat flux sensors for turbine airfoils and combustor liners

The design of durable turbine airfoils that use a minimum amount of cooling air requires knowledge of the heat loads on the airfoils during engine operation. Measurement of these heat loads will permit the verification or modification of the analytical models used in the design process and will improve the ability to predict and confirm the thermal performance of turbine airfoil designs. Heat flux sensors for turbine blades and vanes must be compatible with the cast nickel-base and cobalt-base materials used in their fabrication and will need to operate in a hostile environment with regard to temperature, pressure and thermal cycling. There is also a need to miniaturize the sensors to obtain measurements without perturbing the heat flows that are to be measured.

Atkinson, W. H.↗

NASA NTRS1979

Performance verification and system parameter identification of spacecraft tape recorder control servo

Design adequacy of the lead-lag compensator of the frequency loop, accuracy checking of the analytical expression for the electrical motor transfer function, and performance evaluation of the speed control servo of the digital tape recorder used on-board the 1976 Viking Mars Orbiters and Voyager 1977 Jupiter-Saturn flyby spacecraft are analyzed. The transfer functions of the most important parts of a simplified frequency loop used for test simulation are described and ten simulation cases are reported. The first four of these cases illustrate the method of selecting the most suitable transfer function for the hysteresis synchronous motor, while the rest verify and determine the servo performance parameters and alternative servo compensation schemes. It is concluded that the linear methods provide a starting point for the final verification/refinement of servo design by nonlinear time response simulation and that the variation of the parameters of the static/dynamic Coulomb friction is as expected in a long-life space mission environment.

Mukhopadhyay, A. K.↗

NASA NTRS1983

Cryogenic fluid management experiment trunnion fatigue verification

A subcritical liquid hydrogen orbital storage and transfer experiment was designed for flight in the Shuttle cargo bay. The Cryogenic Fluid Management Experiment (CFME) includes a liquid hydrogen tank supported in a vacuum jacket by two fiberglass epoxy trunnion mounts. This composite material was selected for the trunnions since it provides desirable strength, weight and thermal characteristics for supporting cryogenic tankage. An experimental program was conducted to provide material property and fatigue data for S-glass epoxy composite materials at ambient and liquid hydrogen temperatures and to verify structural integrity of the CFME trunnion supports.

Bailey, W. J.↗

NASA NTRS2006

Formal Verification of the Runway Safety Monitor

The Runway Safety Monitor (RSM) designed by Lockheed Martin is part of NASA's effort to reduce runway accidents. We developed a Petri net model of the RSM protocol and used the model checking functions of our tool SMART to investigate a number of safety properties in RSM. To mitigate the impact of state-space explosion, we built a highly discretized model of the system, obtained by partitioning the monitored runway zone into a grid of smaller volumes and by considering scenarios involving only two aircraft. The model also assumes that there are no communication failures, such as bad input from radar or lack of incoming data, thus it relies on a consistent view of reality by all participants. In spite of these simplifications, we were able to expose potential problems in the RSM conceptual design. Our findings were forwarded to the design engineers, who undertook corrective action. Additionally, the results stress the efficiency attained by the new model checking algorithms implemented in SMART, and demonstrate their applicability to real-world systems.

Siminiceanu, Radu↗

NASA NTRS1982

Computational aerodynamics and design

The role of computational aerodynamics in design is reviewed with attention given to the design process; the proper role of computations; the importance of calibration, interpretation, and verification; the usefulness of a given computational capability; and the marketing of new codes. Examples of computational aerodynamics in design are given with particular emphasis on the Highly Maneuverable Aircraft Technology. Finally, future prospects are noted, with consideration given to the role of advanced computers, advances in numerical solution techniques, turbulence models, complex geometries, and computational design procedures. Previously announced in STAR as N82-33348

Ballhaus, W. F., Jr.↗

NASA NTRS2012

SMAP Verification and Validation Project - Final Report

In 2007, the National Research Council (NRC) released the Decadal Survey of Earth science. In the future decade, the survey identified 15 new space missions of significant scientific and application value for the National Aeronautics and Space Administration (NASA) to undertake. One of these missions was the Soil Moisture Active Passive (SMAP) mission that NASA assigned to the Jet Propulsion Laboratory (JPL) in 2008. The goal of SMAP1 is to provide global, high resolution mapping of soil moisture and its freeze/thaw states. The SMAP project recently passed its Critical Design Review and is proceeding with its fabrication and testing phase.Verification and Validation (V&V) is widely recognized as a critical component in system engineering and is vital to the success of any space mission. V&V is a process that is used to check that a system meets its design requirements and specifications in order to fulfill its intended purpose. Verification often refers to the question "Have we built the system right?" whereas Validation asks "Have we built the right system?" Currently the SMAP V&V team is verifying design requirements through inspection, demonstration, analysis, or testing. An example of the SMAP V&V process is the verification of the antenna pointing accuracy with mathematical models since it is not possible to provide the appropriate micro-gravity environment for testing the antenna on Earth before launch.

Soil Moisture Active Passive (SMAP)↗

NASA NTRS2000

Age and Stress Prediction

Genoa is a software product that predicts progressive aging and failure in a variety of materials. It is the result of a SBIR contract between the Glenn Research Center and Alpha Star Corporation. Genoa allows designers to determine if the materials they plan on applying to a structure are up to the task or if alternate materials should be considered. Genoa's two feature applications are its progressive failure simulations and its test verification. It allows for a reduction in inspection frequency, rapid design solutions, and manufacturing with low cost materials. It will benefit the aerospace, airline, and automotive industries, with future applications for other uses.

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NASA NTRS1995

Experimental Results from the Thermal Energy Storage-1 (TES-1) Flight Experiment

The Thermal Energy Storage-1 (TES-1) is a flight experiment that flew on the Space Shuttle Columbia (STS-62), in March 1994, as part of the OAST-2 mission. TES-1 is the first experiment in a four experiment suite designed to provide data for understanding the long duration microgravity behavior of thermal energy storage fluoride salts that undergo repeated melting and freezing. Such data have never been obtained before and have direct application for the development of space-based solar dynamic (SD) power systems. These power systems will store solar energy in a thermal energy salt such as lithium fluoride or calcium fluoride. The stored energy is extracted during the shade portion of the orbit. This enables the solar dynamic power system to provide constant electrical power over the entire orbit. Analytical computer codes have been developed for predicting performance of a spaced-based solar dynamic power system. Experimental verification of the analytical predictions is needed prior to using the analytical results for future space power design applications. The four TES flight experiments will be used to obtain the needed experimental data. This paper will focus on the flight results from the first experiment, TES-1, in comparison to the predicted results from the Thermal Energy Storage Simulation (TESSIM) analytical computer code. The TES-1 conceptual development, hardware design, final development, and system verification testing were accomplished at the NASA lewis Research Center (LeRC). TES-1 was developed under the In-Space Technology Experiment Program (IN-STEP), which sponsors NASA, industry, and university flight experiments designed to enable and enhance space flight technology. The IN-STEP Program is sponsored by the Office of Space Access and Technology (OSAT).

Wald, Lawrence W.↗

NASA NTRS1971

Preliminary criteria for the fracture control of space shuttle structures

The complex and multidisciplinary factors are presented which relate to the prevention of structural failure due to the initiation or propagation of cracks or crack-like defects. The fracture control criteria are applicable to space shuttle components which are: (1) susceptible to cracking or fracture on the basis of anticipated loads and environment, and (2) critical to either crew safety or system performance. The criteria define the design, fabrication, environmental control, inspection, maintenance, repair, and verification procedures required for adequate fracture control.

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NASA NTRS1981

Integrated Analysis Capability (IAC) development

The technical and programmatic aspects of the integrated analysis capability (IAC) are described. The (IAC) is an interdisciplinary analysis system containing a wide range of general purpose analysis programs that are interfaced via a common data base and a unified executive. The system is designed with significant interactive capability as well as the capability to support the entire range of design phases from the definition phase to the verification phase. The system functions as a standalone or interfaced with IPAD.

Young, J. P.↗

NASA NTRS1982

Flight testing the Rotor Systems Research Aircraft (RSRA)

The Rotor Systems Research Aircraft (RSRA) is a dedicated rotor test vehicle whose function is to fill the gap between theory, wind tunnel tests and flight verification data. Its flight test envelope has been designed to encompass the expected envelopes of future rotor systems under all flight conditions. The test configurations of the RSRA include pure helicopter and compound (winged helicopter) modes. In addition, should it become necessary to jettison an unstable rotor system in flight, the RSRA may be flown as a fixed wing aircraft. The heart of the RSRA's electronic flight control system is the TDY-43 computer, which can be programmed in numerous ways to change stability and control or force feel system gains. Computer programming changes allow the RSRA to be used as a five-degree-of-freedom inflight simulator for studying the handling qualities of research rotors.

Merrill, R. K.↗

NASA NTRS1985

Autonomously managed high power systems

The need for autonomous power management capabilities will increase as the power levels of spacecraft increase into the multi-100 kW range. The quantity of labor intensive ground and crew support consumed by the 9 kW Skylab cannot be afforded in support of a 75-300 kW Space Station or high power earth orbital and interplanetary spacecraft. Marshall Space Flight Center is managing a program to develop necessary technologies for high power system autonomous management. To date a reference electrical power system and automation approaches have been defined. A test facility for evaluation and verification of management algorithms and hardware has been designed with the first of the three power channel capability nearing completion.

Weeks, D. J.↗