Simulation of deployment dynamics of inflatable structures
Analytical simulation of the inflation process of inflatable structures is key to assessing their robust deployment in a space environment.
Inflatable↗
SEARCH · Search NASA
Results for “Deployable structures”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Two Concepts for Deployable Trusses
Two concepts that could be applied separately or together have been suggested to enhance the utility of deployable truss structures. The concepts were intended originally for application to a truss structure to be folded for compact stowage during transport and subsequently deployed in outer space. The concepts may also be applicable, with some limitations, to deployable truss structures designed to be used on Earth. The first concept involves a combination of features that would help to maximize reliability of a structure while minimizing its overall mass, the complexity of its deployment system, and the expenditure of energy for deployment. The deployment system would be integrated into the truss: some of the truss members would contain folding/unfolding-detent mechanisms similar to those in umbrellas; other truss members would contain shape-memory-alloy (SMA) coil actuators (see Figure 1). Upon exposure to sunlight, the SMA actuators would be heated above their transition temperature, causing them to extend to their deployment lengths. The extension of the actuators would cause the structure to unfold and, upon completion of unfolding, the umbrellalike mechanisms would lock the unfolded truss in the fully deployed configuration. The use of solar heating to drive deployment would eliminate the need to carry a deployment power source. The actuation scheme would offer high reliability in that the truss geometry would be such that deployment could be completed even if all actuators were not functioning. Of course, in designing for operation in normal Earth gravitation, it would be necessary to ensure that the SMA actuators could apply forces large enough to overcome the deploymentresisting forces attributable to the weights of the members. The second concept is that of an improved design for the joints in folding members. Before describing this design,
Renfro, John W.↗
Low Cost Large Space Antennas
The mobile communication community could significantly benefit from the availability of low-cost, large space-deployable antennas. A new class of space structures, called inflatable deployable structures, will become an option for this industry in the near future. This new technology recently made significant progress with respect to reducing the risk of flying large inflatable structures in space. This progress can be attributed to the successful space flight of the Inflatable Antenna Experiment in May of 1996, which prompted the initiation of the NASA portion of the joint NASA/DOD coordinated Space Inflatables Program, which will develop the technology to be used in future mobile communications antennas along with other users. The NASA/DOD coordinated Space Inflatables Program was initiated in 1997 as a direct result of the Inflatable Antenna Experiment. The program adds a new NASA initiative to a substantial DOD program that involves developing a series of ground test hardware, starting with 3 meter diameter units and advancing the manufacturing techniques to fabricate a 25 meter ground demonstrator unit with surface accuracy exceeding the requirements for mobile communication applications. Simultaneously, the program will be advancing the state of the art in several important inflatable technology areas, such as developing rigidizable materials for struts and tori and investigating thin film technology issues, such as application of coatings, property measurement and materials processing and assembly techniques. A very important technology area being addressed by the program is deployment control techniques. The program will sponsor activities that will lead to understanding the effects of material strain energy release, residual air in the stowed structure, and the design of the launch restraint and release system needed to control deployment dynamics. Other technology areas directly applicable to developing inflatable mobile communication antennas in the near future are analytical performance prediction tools, configuration studies and miniaturizing the inflation systems.
Chmielewski, Artur B.↗
The development of the 15-Meter Hoop Column deployable antenna system with structural and electromagnetic performance results
This paper presents the technical results obtained during the development and engineering tests of a 15-Meter Hoop Column deployable antenna system. An important element of the 15-meter antenna program was the structural tests and the characterization of the surface accuracy of the deployed mesh surface. The overall system performance of the 15-meter antenna was obtained during radio frequency tests conducted in the Martin Marietta Near Field Test Laboratory in Denver, CO. The near field tests verified the electromagnetic performance of the structure which exhibited a surface accuracy of 0.061 in (RMS). Radio frequency tests were conducted at 2.3, 4.3, 7.7, and 11.6 GHz. The experiment and analytical results obtained through the 15-meter antenna program will provide new opportunities for the application of large space antennas for future missions.
Campbell, T. G.↗
Low Cost Large Space Antennas
The mobile communication community could significantly benefit from the availability of low-cost, large space-deployable antennas. A new class of space structures, called inflatable deployable structures, will becom an option for this industry in the near future.
low-cost↗
Efficient structures for geosynchronous spacecraft solar arrays. Phase 1, 2 and 3
Structural concepts for deploying and supporting lightweight solar-array blankets for geosynchronous electrical power are evaluated. It is recommended that the STACBEAM solar-array system should be the object of further study and detailed evaluation. The STACBEAM system provides high stiffness at low mass, and with the use of a low mass deployment mechanism, full structural properties can be maintained throughout deployment. The stowed volume of the STACBEAM is acceptably small, and its linear deployment characteristic allows periodic attachments to the solar-array blanket to be established in the stowed configuration and maintained during deployment.
Adams, L. R.↗
A Deployable Primary Mirror for Space Telescopes
NASA Langley Research Center, Composite Optics, Inc., and Nyma/ADF have developed jointly a deployable primary mirror for space telescopes that combines over five years of research on deployment of optical-precision structures and over ten years of development of fabrication techniques for optical-precision composite mirror panels and structures. The deployable mirror is directly applicable to a broad class of non-imaging "lidar" (Light direction and ranging) telescopes whose figure-error requirements are in the range of one to ten microns RMS. Furthermore, the mirror design can be readily modified to accommodate imaging-quality reflector panels and active panel-alignment control mechanisms for application to imaging telescopes. The present paper: 1) describes the deployable mirror concept; 2) explains the status of the mirror development; and 3) provides some technical specifications for a 2.55- m-diameter, proof-of-concept mirror.
Lake, Mark S.↗
A Deployable Primary Mirror for Space Telescopes
NASA Langley Research Center, Composite Optics, Inc., and Nyma/ADF have developed jointly a deployable primary mirror for space telescopes that combines over five years of research on deployment of optical-precision structures and over ten years of development of fabrication techniques for optical-precision composite mirror panels and structures. The deployable mirror is directly applicable to a broad class of non-imaging "lidar" (light direction and ranging) telescopes whose figure-error requirements are in the range of one to ten microns RMS. Furthermore, the mirror design can be readily modified to accommodate imaging-quality reflector panels and active panel-alignment control mechanisms for application to imaging telescopes. The present paper: 1) describes the deployable mirror concept; 2) explains the status of the mirror development; and 3) provides some technical specifications for a 2.55-m-diameter, proof-of-concept mirror.
Lake, Mark S.↗
Materials and structures
Materials and structures technology covers a wide range of technical areas. Some of the most pertinent issues for the Astrotech 21 missions include dimensionally stable structural materials, advanced composites, dielectric coatings, optical metallic coatings for low scattered light applications, low scattered light surfaces, deployable and inflatable structures (including optical), support structures in 0-g and 1-g environments, cryogenic optics, optical blacks, contamination hardened surfaces, radiation hardened glasses and crystals, mono-metallic telescopes and instruments, and materials characterization. Some specific examples include low coefficients of thermal expansion (CTE) structures (0.01 ppm/K), lightweight thermally stable mirror materials, thermally stable optical assemblies, high reliability/accuracy (1 micron) deployable structures, and characterization of nanometer level behavior of materials/structures for interferometry concepts. Large filled-aperture concepts will require materials with CTE's of 10(exp 9) at 80 K, anti-contamination coatings, deployable and erectable structures, composite materials with CTE's less than 0.01 ppm/K and thermal hysteresis, 0.001 ppm/K. Gravitational detection systems such as LAGOS will require rigid/deployable structures, dimensionally stable components, lightweight materials with low conductivity, and high stability optics. The Materials and Structures panel addressed these issues and the relevance of the Astrotech 21 mission requirements by dividing materials and structures technology into five categories. These categories, the necessary development, and applicable mission/program development phasing are summarized. For each of these areas, technology assessments were made and development plans were defined.
Saito, Theodore T.↗
Structural/thermal considerations for design of large space platform structures
A method is described for placing a large, STS-compatible platform on orbit utilizing a construction method employing both deployable and erectable structures. A multifunctional mechanism is used for deployable structures and an on-orbit assembly is used for erectable structures. Also analyses are discussed which assess the thermal distortion of a simple open truss and a more complex truss.
Barclay, D. L.↗
The structural and librational dynamics of a satellite deploying flexible booms or antennas.
Structural and librational dynamics of satellite deploying flexible booms or antennas
LIBRATIONAL MOTION↗
Structural concepts for large spacecraft
Design concepts for deployable spacecraft structures are examined with particular emphasis on mass/area optimization, stowability, and assembly, and the relations of these requirements to functional design parameters. Component and modular concepts for platforms and reflectors, structural configurations for long columns, pretension columns, and joint concepts are discussed. A brief overview of astronaut and automated assembly studies is included.
Bush, H. G.↗
Deployable large area solar array structure Preliminary developmental report, phase I
Roller drum, actuation system, support structure, electrical provisions, and substrate design concepts for deployable large area solar array structure
ACTUATOR↗
Foldable Large Reflectors
Reflector deployed from cylindrical package about one-fifth as wide. Large paraboloidal, otherwise curved, or flat reflectors automatically deployable from, and retractable into, compact packages, according to proposal. Reflecting surfaces consist of rigid panels, stacked in compact packages along with deployment mechanisms becoming parts of supporting structures upon deployment.
Mikulas, Martin M., Jr.↗
Controls Modeling Approach for Deployment of a Large Thin Structure for Solar Sails
One of the principal challenges with solar sails is to safely deploy the large sail structures while simultaneously maintaining attitude control. This challenge includes changing moments and products of inertia along with large sail shape uncertainties as it transitions from stowed to the fully deployed shape at the end of the deployment. With these changes, the control system must manage any potential momentum buildup and keep the pointing within mission requirements. The attitude determination and control system team for Solar Cruiser, a 1600 square meter solar sail project out of Marshall Space Flight Center, approached this problem by modeling the nominal moments and products of inertia for different stages of deployment from 10% to 100% in 10% increments. At each step, the inertias were used to generate tuned PID gains, which were used as part of a nominal deployment analysis to prevent unintentional slewing and tumbling. The team created and analyzed off nominal cases, where the moments of inertia and products were changed to induce uncertainties for the control system to manage during deployment. These cases helped verify that the control system can handle off-nominal deployments as well as any uncertainties occurring during deployment of the space sail system. This paper will show this method can be successfully used for modeling solar sail deployments as part of the attitude control system.
Solar Sails↗
Controls Modeling Approach for Deployment of a Large Thin Structures for Solar Sails
One of the principal challenges with solar sails is to safely deploy the large sail structures while simultaneously maintaining attitude control. This challenge includes changing moments and products of inertia along with large sail shape uncertainties as it transitions from stowed to the fully deployed shape at the end of the deployment. With these changes, the control system must manage any potential momentum buildup and keep the pointing within mission requirements. The attitude determination and control system team for Solar Cruiser, a 1600 square meter solar sail project out of Marshall Space Flight Center, approached this problem by modeling the nominal moments and products of inertia for different stages of deployment from 10% to 100% in 10% increments. At each step, the inertias were used to generate tuned PID gains, which were used as part of a nominal deployment analysis to prevent unintentional slewing and tumbling. The team created and analyzed off nominal cases, where the moments of inertia and products were changed to induce uncertainties for the control system to manage during deployment. These cases helped verify that the control system can handle off-nominal deployments as well as any uncertainties occurring during deployment of the space sail system. This paper will show this method can be successfully used for modeling solar sail deployments as part of the attitude control system.
Solar Sails↗
Deployable M-Braced Truss
Tension/compression and shear separated structurally in deployable beam. M-Braced Sections Packaged using combination of hinges and telescoping sections. When upper sections telescope into base, diagonals hinge, telescope, and rotate along batten. Components of M-braced truss fabricated from conventional metallic materials or nonmetallic materials such as graphite/epoxy. Applications include masts for antenna feed horns and ribs for solar array blankets.
Mikulas, M. M., Jr.↗
Development of a verification program for deployable truss advanced technology
Use of large deployable space structures to satisfy the growth demands of space systems is contingent upon reducing the associated risks that pervade many related technical disciplines. The overall objectives of this program was to develop a detailed plan to verify deployable truss advanced technology applicable to future large space structures and to develop a preliminary design of a deployable truss reflector/beam structure for use a a technology demonstration test article. The planning is based on a Shuttle flight experiment program using deployable 5 and 15 meter aperture tetrahedral truss reflections and a 20 m long deployable truss beam structure. The plan addresses validation of analytical methods, the degree to which ground testing adequately simulates flight and in-space testing requirements for large precision antenna designs. Based on an assessment of future NASA and DOD space system requirements, the program was developed to verify four critical technology areas: deployment, shape accuracy and control, pointing and alignment, and articulation and maneuvers. The flight experiment technology verification objectives can be met using two shuttle flights with the total experiment integrated on a single Shuttle Test Experiment Platform (STEP) and a Mission Peculiar Experiment Support Structure (MPESS). First flight of the experiment can be achieved 60 months after go-ahead with a total program duration of 90 months.
Dyer, Jack E.↗