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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

A Survey of CubeSat Deployable Structures: The First Decade

In the past decade CubeSats have made their way into the spotlight. They have evolved from small, university educational opportunities, to industry and governments using them make new discoveries and monetize space. However, with the small, constrained CubeSat form factor; there is often a need to expand the CubeSat through deployable mechanisms once the satellite is in space. This paper is a survey of deployable structures and their actuating mechanisms for CubeSats. The goal of this paper is to provide the applications within which deployable structures have been used in the past for CubeSats, the mechanisms with regards to how they deploy, the lessons learned, and limitations of the various types of deployables. The inputs to this paper come from a relational database in development to track launched CubeSat missions with deployable structures. From this database we can find insightful trends. This paper specifically focuses on the first decade of CubeSat deployables, from 2000 to 2010.

Arya, Manan↗
NASA NTRSDate not supplied

Structural Analysis of Load-Bearing Components in Mars Science Helicopter

The successful demonstration of powered flight on Mars by Ingenuity has led to the development of next generation Martian rotorcraft. As technology advances from a technology demonstrator to possible expanded planetary science investigations, the potential to fly a high payload carrying rotorcraft relies on the capability to analyze and validate the structural integrity of the vehicle in addition to the rotor aerodynamic performance. The Mars Science Helicopter (MSH), a next generation hexacopter concept, is one example of a proposed vehicle that would perform science independently of a land-based vehicle. To ensure the feasibility and viability of MSH mission performance, it is critical to mature the structural design for these vehicle concepts to bridge the gap between the best practices of the spacecraft and aircraft communities. MSH was analyzed under operational and 26G quasi-static launch loads with different rotor arm and fuselage designs. Structural analysis results showed that rotor arms could be stiffened for significantly improved structural performance with minimal mass penalty, while the rotorcraft frame exhibited a more complex relationship between mass and launch load stresses due to the mass-dependent launch loads.

Load-Bearing↗
NASA NTRS2025

Structural Analysis of Load-Bearing Components in Mars Science Helicopter

The successful demonstration of powered flight on Mars by Ingenuity has led to the development of next generation Martian rotorcraft. As technology advances from a technology demonstrator to possible expanded planetary science investigations, the potential to fly a high payload carrying rotorcraft relies on the capability to analyze and validate the structural integrity of the vehicle in addition to the rotor aerodynamic performance. The Mars Science Helicopter (MSH), a next generation hexacopter concept, is an example of a proposed vehicle that would perform science investigations independent of a land-based vehicle. To ensure the feasibility and viability of MSH mission performance, it is critical to mature the structural design of vehicle concepts to bridge the gap between the best practices of the spacecraft and aircraft communities. MSH was analyzed under operational and 26G quasi-static launch loads with different rotor arm and frame designs. Structural analysis results showed that rotor arms could be stiffened for significantly improved structural performance with minimal mass penalty, while the rotorcraft frame exhibited a more complex relationship between mass and launch load stresses due to the mass-dependent launch loads.

Vehicle↗
NASA NTRS1978

Foam For Filtering

Like nature's honeycomb, foam is a structure of many-sided cells, apparently solid but actually only three percent material and 97 percent air. Foam is made by a heat-producing chemical reaction which expands a plastic material in a manner somewhat akin to the heat-induced rising of a loaf of bread. The resulting structure of interconnected cells is flexible yet strong and extremely versatile in applicati6n. Foam can, for example, be a sound absorber in one form, while in another it allows sound to pass through it. It can be a very soft powder puff material and at the same time a highly abrasive scrubber. A sampling of foam uses includes stereo speaker grilles, applying postage meter ink, filtering lawnmower carburetor air; deadening noise in trucks and tractors, applying cosmetics, releasing fabric softener and antistatic agents in home clothes dryers, painting, filtering factory heating and ventilating systems, shining shoes, polishing cars, sponge-mopping floors, acting as pre-operative surgical scrubbers-the list is virtually limitless. The process by which foam is made produces "windows," thin plastic membranes connecting the cell walls. Windowed foam is used in many applications but for certain others-filtering, for example-it is desirable to have a completely open network. Scott Paper Company's Foam Division, Chester, Pennsylvania, improved a patented method of "removing the windows," to create an open structure that affords special utility in filtering applications. NASA technology contributed to Scott's improvement.

Source record↗
NASA NTRS1989

Innovative architectures for dense multi-microprocessor computers

The purpose is to summarize a Phase 1 SBIR project performed for the NASA/Langley Computational Structural Mechanics Group. The project was performed from February to August 1987. The main objectives of the project were to: (1) expand upon previous research into the application of chordal ring architectures to the general problem of designing multi-microcomputer architectures, (2) attempt to identify a family of chordal rings such that each chordal ring can be simply expanded to produce the next member of the family, (3) perform a preliminary, high-level design of an expandable multi-microprocessor computer based upon chordal rings, (4) analyze the potential use of chordal ring based multi-microprocessors for sparse matrix problems and other applications arising in computational structural mechanics.

Larson, Robert E.↗
NASA NTRS1991

Analysis and characterizations of planar transmission structures and components for superconducting and monolithic integrated circuits

The analysis and modeling of superconducting planar transmission lines were performed. Theoretically, the highest possible Q values of superconducting microstrip line was calculated and, as a result, it provided the Q value that the experiment can aim for. As an effort to search for a proper superconducting transmission line structure, the superconducting microstrip line and coplanar waveguide were compared in terms of loss characteristics and their design aspects. Also, the research was expanded to a superconducting coplanar waveguide family in the microwave packaging environment. Theoretically, it was pointed out that the substrate loss is critical in the superconducting transmission line structures.

Itoh, Tatsuo↗
NASA NTRS1983

Direct structural parameter identification by modal test results

A direct identification procedure is proposed to obtain the mass and stiffness matrices based on the test measured eigenvalues and eigenvectors. The method is based on the theory of matrix perturbation in which the correct mass and stiffness matrices are expanded in terms of analytical values plus a modification matrix. The simplicity of the procedure enables real time operation during the structural testing.

Chen, J.-C.↗
NASA NTRS1977

The compact radio sources in 4C 39.25 and 3C 345

Long-baseline interferometry of the quasars 4C 39.25 and 3C 345 at 10.65 and 14.77 GHz shows that the centimeter radio source in each object is double, with component separations of 0.0020 arcsec (4C 39.25) and 0.0013 arcsec (3C 345 at 1974.5). For each source, the separation is the same at both frequencies, as well as similar to the structure observed at 7.85 GHz (and 5.0 GHz for 4C 39.25). The spectra of the individual components are derived and shown to vary with time approximately as expected for expanding self-absorbed synchrotron sources. The magnetic fields in the components are estimated to be as high as 0.1 gauss, but the structure of the sources appears to be unrelated to the magnetic-field orientation derived from low-resolution polarization measurements. The component separation in 4C 39.25 has not changed for several years, whereas 3C 345 shows rapid expansion.

Shaffer, D. B.↗
NASA NTRSDate not supplied

Innovations in Continuous Ultrasonic Welding of Thermoplastic Composites and Evaluation for Space Applications

The goals of NASA’s Thermoplastic Development for Exploration Applications (TDEA) Project include and assessment of thermoplastic composite joints for space structures by developing and maturing design capabilities, analysis tools and techniques, and manufacturing processes for thermoplastic composites. Through this effort the TDEA project will expand NASA’s in-house thermoplastic composite manufacturing capabilities, develop an understanding of advanced thermoplastic joining techniques relevant to space environments, evaluate the feasibility of reconfigurable composite structures, and advance structural analysis capabilities, including failure prediction of thermoplastic composites including joints. This presentation will provide an overview of the materials and manufacturing effort within the TDEA project. Three semi-crystalline and one amorphous thermoplastic composite system were selected for initial screening and provided an opportunity to gain manufacturing experience across a range of processing temperatures, rheological behavior, and composite properties. Equivalency to the National Center for Advanced Materials Performance (NCAMP) test report for Toray’s TC1225 material was established to provide confidence in in-house manufacturing and material properties were generated through baseline mechanical tests for each material. Material characterization data was generated for a subset of materials to (1) provide data for analysis and model development and (2) generate thermal, rheological and conductivity data across relevant temperatures. A key objective of the TDEA project is evaluation of thermoplastic composite joining processes suitable for in-space operations. This presentation will outline the project’s progress in fusion bonding candidate materials by common welding techniques to assess the quality, reproducibility and strength of the bond, as well as identify limitations to in-space manufacturing. The feasibility of joint disassembly and reassembly will be discussed.

thermoplastic composite↗
NASA NTRSDate not supplied

Manufacture, Characterization, and Fusion Welding of Thermoplastic Composites for Space Applications

The goals of NASA’s Thermoplastic Development for Exploration Applications (TDEA) Project include an assessment of thermoplastic composite joints for space structures by developing and maturing design capabilities, analysis tools and techniques, and manufacturing processes for thermoplastic composites. Through this effort the TDEA project will expand NASA’s in-house thermoplastic composite manufacturing capabilities, develop an understanding of advanced thermoplastic joining techniques relevant to space environments, evaluate the feasibility of reconfigurable composite structures, and advance structural analysis capabilities. This presentation will provide an overview of the materials and manufacturing effort within the TDEA project. Three semi-crystalline and one amorphous thermoplastic composite materials were selected for initial screening and provided an opportunity to gain manufacturing experience across a range of processing temperatures, rheological behavior, and composite properties. Equivalency to the National Center for Advanced Materials Performance (NCAMP) test report for Toray’s TC1225 material was established to provide confidence in in-house manufacturing and material properties were generated through baseline mechanical tests for each material. Material characterization data was generated for a subset of materials to (1) provide data for analysis and model development and (2) generate thermal, rheological and conductivity data across relevant temperatures. A key objective of the TDEA project is evaluation of thermoplastic composite joining processes suitable for in-space operations. This presentation will outline the project’s progress in fusion bonding of candidate materials to assess the quality, reproducibility and strength of the bond, as well as identify limitations to in-space manufacturing. The feasibility of joint disassembly and reassembly will be discussed.

thermoplastic composite↗
NASA NTRSDate not supplied

Manufacture, Characterization, and Fusion Welding of Thermoplastic Composites for Space Applications

The goals of NASA’s Thermoplastic Development for Exploration Applications (TDEA) Project include an assessment of thermoplastic composite joints for space structures by developing and maturing design capabilities, analysis tools and techniques, and manufacturing processes for thermoplastic composites. Through this effort the TDEA project will expand NASA’s in-house thermoplastic composite manufacturing capabilities, develop an understanding of advanced thermoplastic joining techniques relevant to space environments, evaluate the feasibility of reconfigurable composite structures, and advance structural analysis capabilities.1

thermoplastic composite↗
NASA NTRSDate not supplied

Manufacture, Characterization, and Fusion Welding of Thermoplastic Composites for Space Applications

The goals of NASA’s Thermoplastic Development for Exploration Applications (TDEA) Project include and assessment of thermoplastic composite joints for space structures by developing and maturing design capabilities, analysis tools and techniques, and manufacturing processes for thermoplastic composites. Through this effort the TDEA project will expand NASA’s in-house thermoplastic composite manufacturing capabilities, develop an understanding of advanced thermoplastic joining techniques relevant to space environments, evaluate the feasibility of reconfigurable composite structures, and advance structural analysis capabilities, including failure prediction of thermoplastic composites including joints. This presentation will provide an overview of the materials and manufacturing effort within the TDEA project. Three semi-crystalline and one amorphous thermoplastic composite system were selected for initial screening and provided an opportunity to gain manufacturing experience across a range of processing temperatures, rheological behavior, and composite properties. Equivalency to the National Center for Advanced Materials Performance (NCAMP) test report for Toray’s TC1225 material was established to provide confidence in in-house manufacturing and material properties were generated through baseline mechanical tests for each material. Material characterization data was generated for a subset of materials to (1) provide data for analysis and model development and (2) generate thermal, rheological and conductivity data across relevant temperatures. A key objective of the TDEA project is evaluation of thermoplastic composite joining processes suitable for in-space operations. This presentation will outline the project’s progress in fusion bonding candidate materials by common welding techniques to assess the quality, reproducibility and strength of the bond, as well as identify limitations to in-space manufacturing. The feasibility of joint disassembly and reassembly will be discussed.

thermoplastic composite↗
NASA NTRS1975

Liquid film demonstration experiment Skylab SL-4

The liquid film demonstration experiment performed on Skylab 4 by Astronaut Gerald Carr, which involved the construction of water and soap films by boundary expansion and inertia, is discussed. Results include a 1-ml globule of water expanded into a 7-cm-diameter film as well as complex film structures produced by inertia whose lifetimes are longer in the low-g environment. Also discussed are 1-g acceleration experiments in which the unprovoked rupture of films was photographed and film lifetimes of stationary and rotated soap films were compared. Finally, there is a mathematical discussion regarding minimal surfaces, an isoperimetric problem, and liquid films.

Darbro, W.↗
NASA NTRS1982

The observation of a coronal transient directed at earth

The paper reports the observation of a large coronal transient that can only be interpreted as a three-dimensional structure. Its form is one which has not been observed before: a gradually expanding, sun-centered disk of excess brightness, whose projected radius increased from 4 to 8 solar radii during 0832-0958 UT on November 27, 1979. This earth-directed transient was the source of an interplanetary shock wave that reached ISEE 3 at 0649 UT, November 30, and earth at 0738 UT, November 30. Fitting the shock speed at ISEE 3 and the average transit speed from the sun to ISEE 3 to a power law of the form V = (V sub 0)(r exp -n), it is found that V sub 0 = 1980 km/s and n = 0.294, in good agreement with shock wave models. The shock speed predicted by the power law at 10 solar radii is 1000 km/s, in good agreement with the estimated frontal speed of the transient.

Howard, R. A.↗
NASA NTRS1986

Systolic VLSI for Kalman filters

A novel two-dimensional parallel computing method for real-time Kalman filtering is presented. The mathematical formulation of a Kalman filter algorithm is rearranged to be the type of Faddeev algorithm for generalizing signal processing. The data flow mapping from the Faddeev algorithm to a two-dimensional concurrent computing structure is developed. The architecture of the resulting processor cells is regular, simple, expandable, and therefore naturally suitable for VLSI chip implementation. The computing methodology and the two-dimensional systolic arrays are useful for Kalman filter applications as well as other matrix/vector based algebraic computations.

Yeh, H.-G.↗
NASA NTRS1992

LDEF materials overview

The flight and retrieval of the LDEF provided an opportunity for the study of the low earth orbit (LEO) environment and long-duration space environmental effects (SEE) on materials that is unparalleled in the history of the US space program. The 5-year, 9-month flight of the LDEF greatly enhanced the potential value of all materials on the LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of the LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials on the same vehicle. NASA recognized this potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment parameter analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements, so that the combined value of all LDEF materials data to current and future space missions are addressed and documented. This presentation provides an overview of the interim LDEF materials findings of the principal investigators and the MSIG.

Stein, Bland A.↗
NASA NTRS1992

Structure and evolution of time-dependent intermediate shocks

A quantitative description of time-dependent intermediate shocks is formulated using the Cohen-Kulsrud-Burgers equations. In noncoplanar Riemann problems, time-dependent two-three transition intermediate shocks evolve in time as a localized self-similar structure whose strength decreases as 1/the square root of t, and whose width expands as the square root of t. Time-dependent intermediate shocks offer a way of solving the noncoplanar MHD Riemann problem.

Wu, C. C.↗
NASA NTRS1992

LDEF materials: An overview of the interim findings

The flight and retrieval of the National Aeronautics and Space Administration's Long Duration Exposure Facility (LDEF) provided an opportunity for the study of the low-Earth orbit (LEO) environment and long-duration space environmental effect (SEE) on materials that are unparalleled in the history of the U.S. space program. The 5.8-year flight of LDEF greatly enhanced the potential value of materials data from LDEF to the international SEE community, compared to that of the original 1-year flight plan. The remarkable flight attitude stability of LDEF enables specific analyses of various individual and combined effects of LEO environmental parameters on identical materials of the same space vehicle. NASA recognized the potential by forming the LDEF Space Environmental Effects on Materials Special Investigation Group (MSIG) to address the greatly expanded materials and LEO space environment parameter analysis opportunities available in the LDEF structure, experiment trays, and corollary measurements, so that the combined value of all LDEF materials data to current and future space missions will be assessed and documented. This paper provides an overview of the interim LDEF materials findings of the Principal Investigators and the Materials Special Investigation Group. These revelations are based on observations of LEO environmental effects on materials made in-space during LDEF retrieval and during LDEF tray deintegration at the Kennedy Space Center, and on findings of approximately 1.5 years of laboratory analyses of LDEF materials by the LDEF materials scientists. These findings were extensively reviewed and discussed at the MSIG-sponsored LDEF Materials Workshop '91. The results are presented in a format which categorizes the revelations as 'clear findings' or 'confusing/unexplained findings' and resultant needs for new space materials developments and ground simulation testing/analytical modeling in seven categories: environmental parameters and data bases; LDEF contamination; thermal control coatings and protective treatments; polymers and films; polymer-matrix composites; metals, ceramics, and optical materials; and systems-related materials. General outlines of findings of the other LDEF Special Investigation Groups (Ionizing Radiation, Meteoroid and Debris, and Systems) are also included. The utilization of LDEF materials data for future low-earth orbit missions is also discussed, concentrating on Space Station Freedom. Some directions for continuing studies of LDEF materials are outlined. In general, the LDEF data is remarkable consistent; LDEF will provide a 'benchmark' for materials design data bases for satellites in low-Earth orbit. Some materials were identified to be encouragingly resistant to LEO SEE for 5.8-years; other 'space qualified' materials displayed significant environmental degradation. Molecular contamination was widespread; LDEF offers an unprecedented opportunity to provide a unified perspective of unmanned LEO spacecraft contamination mechanisms. New material development requirements for long-term LEO missions have been identified and current ground simulation testing methods/data for new, durable materials concepts can be validated with LDEF results. LDEF findings are already being integrated into the design of Space Station Freedom.

Stein, Bland A.↗