Deployable Truss Structure Research Articles

Technology status of the 13 m aperture deployment antenna reflectors for engineering test satellite VIII

Large deployable antenna reflectors for Engineering Test Satellite VIII (ETS-VIII) are now stated in the critical design phase. The Fourteen 4.8m modules, which construct a 19.2 m × 16.7 m (13m aperture) antenna reflector, have been fabricated as Engineering Models. Ground testing for the fourteen modules will be performed until next spring. This paper describes results of critical design for the antenna reflectors and their validation plans. Each module consists of a gold-plated molybdenum mesh surface, spacially determined cable network, and a deployable truss structure as a supporting structure. Stowed size is 1 m (diameter) × 4 m (height). In stowed configuration, the lowest eigen frequencies of the antenna reflector are 47 Hz (longitudinal) and 69 Hz (lateral) respectively. The lowest eigen frequency is 0.14 Hz. Solar ray transparency of the reflector structure is designed to be more than 85% to avoid excessive solar pressure torque. Weight of each reflector is expected to be less than 100 kg. In addition, we will perform a piggyback deployment experiment in transfer orbit using the second stage of the first flight H-II A vehicle in 2000. Half scale seven modules antenna reflector will be used to validate its deployment reliability. Design, analysis and test results of LDR-P are also introduced in this paper.

Deployment analysis of large space antenna using flexible multibody dynamics simulation

Flexible multibody dynamics is applied to the deployment analysis of a large space antenna composed of a reflective mesh, a cable network and a deployable truss structure. It is clarified that the tension of some of the cables increase when the reflector is stowed. The largest deployment force is observed slightly before the completion of the deployment. A proper allocation of both translational and rotational springs can provide an efficient deployment force. A deployment experiment on a 4.8 m aperture reflector model verifies the computational results. It is concluded that a flexible multibody dynamics simulation is an indispensable design tool for reducing the weight and ensuring the secure deployment of low-cost mesh reflectors.

Analyses of cable–membrane structure combined with deployable truss

The authors have been developing a large deployable mesh reflector for advanced satellite communication. This large reflector consists of a mesh membrane surface and a deployable truss structure. In this paper, analysis methods for a large deployable mesh reflector structure are introduced, and the theoretical basis for the analysis is explained. By using those analysis methods, we manufactured prototype reflector modules and carried out an experiment on them. The validity of the analysis methods were verified from the results of the analyses and experiments. The design procedure of mesh reflector surface and the effect of the mesh surface tension on the truss deployment are discussed.

Design of a Deployable Antenna Truss Structure with Telescopic Members.

This paper describes a method for building three-dimensional deployable truss structures from the viewpoint of deployment reliability.In this regard a method is proposed for designing a closed-loop deployable truss structure for future large space antennas through a kinematic degree-of-freedom analysis of the mechanical system.Using this method, it is possible to attain a truss structure with the appropriate constraints.We have designed and fabricated a prototype and achieved successful deployment under a microgravity environment yielded by parabolic aircraft flight.Hence, the results have demonstrated the effectiveness of deployable truss design using kinematic degree-of-freedom analysis.

Design of a Deployable Antenna Truss Structure with Variable-Length Members.

We describe how to build three-dimensional deployable truss structures from the viewpoint of deployment reliability. We propose a method for designing a closed-loop deployable truss structure for a future large space antenna by using a kinematic degree-of-freedom analysis of the mechanical system. Using this method, it is possible to attain a truss structure with the appropriate constraints. We have designed and fabricated a prototype of the proposed antenna truss structure, and have achieved successful deployment under the microgravity environment yielded by the parabolic flight trajectory of an aircraft. Thus we have demonstrated the effectiveness of the deployable truss structure design using the kinematic degree-of-freedom analysis.

ロボットによる宇宙構造物の地上組立実験

A design methodology of both space structure beam and construction robot is described from the point of total cost minimum. The study is experimentally investigated. At first, two types of beams are prepared. One is a deployable truss structure. This truss is stowed in a rocket fairing folded, and is then deployed in orbit. The other is a putting-pipe-in-socket type beam in which members are separated from the beam, and then these are put in joints in orbit. In this paper secondly, ground experiment on beam construction with an industrial manipulator system are reported. The experiment proves that the dual arm system can conduct both types of beam. Furthermore, it obtains useful system requirements for structure beams. In conclusion, a design of both space structure beam and construction robot is proposed.

Comparative analysis of deployable truss structures for mesh antenna reflectors

Comparative analysis of deployable truss structures for mesh antenna reflectors

Module composition and deployment method on deployable modular-mesh antenna structures

A deployable modular-mesh antenna is the concept behind a large space antenna. To ensure reliable deployment, a synchronously deployable truss structure forming a curved reflector surface has been developed. The proposed antenna's main reflector formed by two types of modules using mesh and cable network maintains a sufficient level of rigidity at deployment and deploys with high reliability. Importance has also been placed on the numerical analyses of cables, the mesh, and the truss structures. The truss structure analysis is based on a non-linear finite element method, rather than on multi-body dynamics, so that elastic motions of all truss members during the deployment can easily be handled.

Two-dimensional deployable hexapod truss

A two-dimensionally deployable truss structure is newly proposed for space application, whose most significant feature is its small number of mechanisms to be locked when it is deployed. Its packaging efficiency is shown to be better than many known deployable trusses. Several versions of the truss are also proposed. To confirm that the new deployable truss has enough design flexibility, a paraboloidal truss platform is designed for trial. Furthermore, a numerical investigation shows that the platform is actually deployable/foldable from the practical point of view.

Kinematic Synthesis of Deployable-Foldable Truss Structures Using Graph Theory, Part 1: Graph Generation

Kinematic structural synthesis has been relatively successful when applied to the conceptual design of mechanisms. The approach presented in this paper, however, views the design process from an initial standpoint of a truss structure. First, graphs are generated that represent truss structures with a given number of nodes and links. Each graph is then modified by designating certain edges in the graph to represent links in the structure that incorporate additional degrees of freedom. In so doing, the graph of a structure is transformed into one representing a mechanism. A procedure is presented that enables the exhaustive generation of these graphs for deployable structures of any given number of nodes and links. From these graphs, it is then possible to obtain enumerable novel deployable truss structures as well as those that have been reported in the literature.

Deployable Modular Mesh Antenna and its Surface Adjustment

The deployable modular mesh antenna is composed of independently fabricated and tested antenna modules to reduce difficulties in ground testing. Each module comprises a metallic mesh shaped by a cable nework and a deployable truss structure. This paper states the basic constitution of each module, especially of the cable network, and results of surface shape adjustment simulations and experiments. Employing the present method, reflector distortions after the fabrication can be adjusted by changing cable lengths without any sensitivity analysis. Numerical simulations and experiments clarify that the attainable surface accuracy of a module is determined mainly by the accuracy of the truss structure.

A Sequentially Deployable Truss for Attached Payloads

Future space applications include very large elements, whose in orbit configuration cannot be launched in a single flight by the existing launchers. Deployable structures present great advantages in this field, as the mass and volume savings that can be achieved are significant. SENER has carried out, under ESA contract, a study to develop, manufacture and test a deployable Large Truss Structure (LTS), that meets the requirements for the mid-term applications foreseen within the European scenario. This paper presents the design, analysis, manufacturing and test phases of a full scale three-module Engineering Model of the LTS.

Two-dimensional deployable truss structures for space applications

Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.