Deployment Reliability Research Articles

Boom-Membrane Space Structure’s Incomplete Deployment After Storage in OrigamiSat-1 Ground Demonstrator

This study investigates the deployment reliability of multifunctional membrane deployable space structures that can be compactly stored and deployed in a two-dimensional direction using carbon composite booms to realize the construction of thin-film solar arrays and membrane antennas. Herein, two aspects are experimentally clarified using the structural models of a nano-satellite OrigamiSat-1, which is a 1 m-by-1 m square multifunctional deployable membrane structure demonstrator. First, a measurement system is developed to quasi-statically quantify the deployment torque of the structural models that failed to complete deployment after long-term storage and fell into an undesirable equilibrium shape. The measurement results confirm that the deployment torque decreases with long-term storage of the structure, and the torque in the deployment direction becomes negative at the deployment angle of the undesirable equilibrium shape. Therefore, as the second contribution, design modifications are made to the boom and membrane, and quasi-static and dynamic deployment tests are employed to evaluate their effects. The deployment reliability evaluation method and two design updates proposed herein will contribute to future space demonstrations and the utilization of lightweight membrane deployment structures with high packaging efficiency.

High Speed Fighter UAV with Electric Coil Gun

The paper focus on "High-Speed Fighter Drone Using Electromagnetic Coil Gun and Dropping Mechanism" project represents a significant milestone in the realm of unmanned aerial vehicles (UAVs). This project aimed to design, develop, and demonstrate a cutting-edge high-speed fighter drone equipped with an electromagnetic coil gun and an advanced payload deployment mechanism. The primary objectives were to enhance drone maneuverability, achieve precision targeting capabilities, and enable efficient payload deployment, thus expanding the potential applications of UAV technology. This project involved an intricate blend of engineering, innovation, and technology integration. The drone's design and construction incorporated a lightweight yet durable frame, high-speed motors, and advanced flight control systems, ensuring exceptional agility and stability during flight. The electromagnetic coil gun, a pivotal component, was meticulously designed for precision targeting, delivering impressive accuracy and firing control. Moreover, the payload deployment mechanism, a vital feature of the system, was developed to ensure the precise and reliable delivery of payloads, expanding the drone's versatility across various domains, including defense, surveillance, and emergency response Throughout the project's lifecycle, rigorous testing, calibration, and data analysis were conducted to validate the drone's performance, accuracy of the electromagnetic coil gun, and efficiency of the payload deployment mechanism. The project yielded promising results, demonstrating the drone's exceptional flight performance, electromagnetic coil gun's precision targeting, and payload deployment's reliability. This project report provides a comprehensive overview of the project's objectives, methodologies, results, and significance. It explores the intricate system design, integration processes, testing procedures, and detailed analyses of outcomes. Furthermore, it discusses the challenges faced during development and the potential impact of this high- speed fighter drone in various industries. In conclusion, the "High-Speed Fighter Drone Using Electromagnetic Coil Gun and Dropping Mechanism" project represents a significant leap forward in UAV technology. Its successful realization opens up new possibilities for drone applications, promising advancements in precision targeting, payload deployment, and the overall versatility of UAVs in both civilian and military contexts

An active jet-based deployment mechanism for improved aerodynamic performance and thermal protection of reentry vehicles

As the demand for interplanetary transportation and deep space exploration missions continues to grow, deployable reentry vehicles have garnered significant attention due to their effective aerodynamic capture and deceleration capabilities, making them a focal point of research for nearly half a century. In reentry flight, traditional motor-driven deployment methods face risks and challenges such as insufficient motor energy supply, low deployment reliability, excessive weight, occupancy of payload space, and potential electromagnetic interference. If deployment failure occurs, it can significantly impact the safety of the flight mission. To address these challenges, this study proposes a jet-based deployment strategy utilizing shoulder thrusters. By carefully designing the associated parameters, this strategy offers a viable alternative to motor-driven mechanisms for deployment tasks. Furthermore, the aerodynamic simulations of the deployment process are conducted, considering various operating conditions, to investigate the influence of deployment angles on the flow field and to compare the aerodynamic performance of the two strategies. Additionally, a comparative analysis of the mass characteristics is conducted. The results show that the jet-based deployment strategy achieves desired objectives and offers advantages such as reduced drag, increased heat flux, enhanced stability, reduced mass, and improved space utilization. These findings have significant engineering implications and pave the way for widespread applications in the future.

Inflatable antenna structures: Deployment analysis of torus bounded Z-fold scalable planar membrane reflector

Compact packaging and smooth deployment reliability, lightweight and large operational size are ideal requirements of inflatable space structures. Space inflatable antenna, one of the recent ask, demands post-deployment surface flatness in addition to ideal necessities. The work in this paper employs a novel technique namely collective zig-zag folding for an inflatable torus and planar reflector assembly. This research accomplishes various tasks with a focus on planar inflatable antenna by solving the drawback of surface flatness in an origami packaging approach. The torus-reflector assembly is compactly packed by employing two different crease orientation strategies. Aiming at large-scale structure, the deployment behaviour of inflatable antenna assembly is investigated experimentally and numerically. The in-plane loading of a torus due to inflation pressure is derived, followed by the calculation of force induced on the outer edge of the inflated torus. The quasi-static deployment by varying the inflation pressure from a few up to several hundreds of kPa is solved to determine the inflated shapes and deployment behaviour of a fully-folded structure. Uniform pressure method was used to observe the effect of fold-lines on deployment instability. Force–displacement response gives insight into the wrinkling in the creased planar reflectors. The shape of the inflated assembly is found to be close to experimental models for the same amount of inflation pressure. The wrinkles and overall surface error lie within expected range as depicted from comparison.

Parametric design optimization approach to petal-type solid surface deployable reflectors

A parametric design approach to the petal-type solid surface deployable reflector is presented, in which the generic parametric model of the reflector is established and its division parameters are optimized to simplify the structure, increase deployment reliability and improve electrical performance. For this goal, the estimated expression of the division number of petals is first derived as the initial value of subsequent optimization algorithm. Then the estimation-trial algorithm is developed, its corresponding three-level nested optimization model is established, and the reference circle model for improving the efficiency in solving the aforementioned model is proposed. Furthermore, the deployment scheme of this kind of reflectors is implemented by Euler’s rotation theorem combined with rigid-body registration. In addition, the parameter analysis is made to determine which parameters dominate the division number of petals. Finally, the effectiveness of this method in configuration, deployment and optimality together with the improvement in deployment reliability and electrical performance are verified. It is revealed that reflectors designed with this method need fewer petals compared with the existing reflectors of this class, deploy smoothly, have lower deployment failure probability, as well as have higher antenna gains and lower relative sidelobe levels. The results indicate the petal-type solid surface deployable reflector characterized by compact structure, high reliability and good electrical performance can be obtained with the approach proposed in this paper.

Tension Calibration Technique for Pre-tightened Wire Rope with Both Ends Fixed Measured by Tensiometer

The tension precision of pre-tightened wire rope with both ends fixed (PWRBEF) was very important for closed loop configuration (CCL) module of the satellite solar array. A high-precision, high-reliability and high-efficiency tension calibration technology for PWRBEF measured by tensiometer was presented in this paper. With the technique, a portable tension calibration system was established to carry on the calibration experiments, which can decouple the measurement error caused by all factors. The single or multiple factors relationship were analysed to eliminate the measurement error of PWRBEF. Depending on the experiments results, the calibration database was built to test and adjust the tension of the PWRBEF in the CCL module. The high compliance and consistency between the adjustment results of tension and the design requirements had been achieved. The deployment synchronization and deployment reliability of the solar array were effectively ensured.

Influence and experiment of cable-net manufacturing errors on surface accuracy of mesh reflector antennas

Cable-net structures are of substantial importance in the construction of large mesh reflector antennas. Owing to the inevitable errors in their manufacturing process, the reflector surface accuracy deteriorates. This study makes a comprehensive investigation of random manufacturing errors during constructing the mesh reflector antennas, and analyze its influence on reflector surface accuracy. Firstly, the sensitivity of reflector surface accuracy with respect to the random errors of the unstressed cable length is mathematically deducted. Secondly, a non-button connecting method is proposed and analyzed to reduce manufacturing errors. Thirdly, two physical experiment models based on 2.62-meter mesh reflector antenna are made. Finally, numerical examples and experimental tests are given to demonstrate the effectiveness of the proposed method. Compared with the traditional method, the proposed method can effectively reduce the influence of the manufacturing errors on the reflector surface accuracy. Moreover, the reduction in the sizes of the nodes also reduces the risk of entanglement of the mesh reflector antenna during the deployment process, and thereby improves the deployment reliability.

Deployment dynamical numerical simulation on large elliptical truss antenna

With the unique advantages in the application of bias-feed high-precision mesh antennas, the large elliptical truss antenna (LETA) attracts attention of many scholars. Due to the complexity of the LETA deployment process, there are some potential risks in orbit development. The successful deployment of antenna on orbit is the key to determine the success or failure of satellite missions. In order to improve the deployment reliability and the load safety of the components of the antennas, the dynamic characteristics of the LETA must be fully identified by the means of simulation, and the load characteristics of the components during the deploying process must be obtained. As a typical flexible multi-body system, a geometric precise beam is used to model bars with large deformation in the LETA and the flexible driving cable is modeled based on one-dimensional dynamic medium dynamics theory. The dynamic modeling and numerical simulation of the deploying process are presented in the paper. On this basis, the unsynchronized phenomenon is analyzed, which is caused mainly by the flexibility of components and the friction loss of driving cable through the hinges. In addition, from the perspective of energy, it shows that friction loss and mesh tension are the most important factors affecting the loads of driving cable and truss. Finally, the design optimization suggestions are given to improve the reliability.

SMA Damped Tape Spring Hinge for Quasi-Static Deployment of a Satellite Solar Array

A tape spring hinge is one of the most typical deployment devices and is frequently used in miniaturized satellite due to its simplicity, lightweight, low cost and high deployment reliability. But a tape spring hinge mechanism has limited performance due to the performance trade-off between deployed stiffness and latch-up shock.In this study, to improve a conventional tape spring hinge mechanism, SMA damped tape spring hinge is proposed so that a satellite solar array can be quasi-statically deployed. The test result shows the feasibility of the proposed concept.

A novel tape spring hinge mechanism for quasi-static deployment of a satellite deployable using shape memory alloy

A tape spring hinge (TSH) is a typical flexible deployment device for a satellite and becomes frequently used due to its simplicity, lightweight, low cost, and high deployment reliability. However, the performance of a TSH is quite limited due to trade-offs among deployed stiffness, deployment torque, and latch-up shock despite its many advantages. In this study, a novel conceptual design that circumvents the trade-offs among functional requirements (FRs) is proposed. The trade-offs are obviated by a newly proposed shape memory alloy damper that converts the deployment behavior of a conventional TSH from unstable dynamic to stable quasi-static. This makes it possible to maximize the deployment stiffness and deployment torque of a conventional TSH, which are larger-the-better FR, without any increase in the latch-up shock. Therefore, in view of conceptual design, it is possible to design a highly improved TSH that has much higher deployed stiffness and deployment torque compared to a conventional TSH while minimizing latch-up shock and deployment unstableness. Detailed design was performed through response surface method and finite element analysis. Finally, a prototype was manufactured and tested in order to verify its performance (four point, deployment torque, and latch-up shock tests). The test results confirm the feasibility of the proposed TSH mechanism.

Advances in deployable structures and surfaces for large apertures in space

Large apertures in space have applications for telecommunications, Earth observation and scientific missions. This paper reviews advances in mechanical architectures and technologies for large deployable apertures for space antennas and telescopes. Two complementary approaches are described to address this challenge: the deployment of structures based on quasi-rigid members and highly flexible structures. Regarding the first approach, deployable articulated structures are classified in terms of their kinematics as 3D or planar linkages in multiple variants, resulting in different architectures of radial, peripheral or modular constructions. A dedicated discussion on the number of degrees of freedom and constraints addresses the deployment reliability and thermo-elastic stability of large elastic structures in the presence of thermal gradients. This aspect has been identified as a design driver for new developments of peripheral ring and modular structures. Meanwhile, other design drivers are maintained, such as the optimization of mass and stiffness, overall accuracy and stability, and pragmatic aspects including controlled industrial development and a commitment to operators’ needs. Furthermore, reflecting surface technologies and concepts are addressed with a view to the future, presenting advances in technical solutions for increasing apertures and reducing areal mass densities to affordable levels for future missions. Highly flexible materials capable of producing ultra-stable shells are described with reference to the state of the art and new developments. These concepts may enable large deployable surfaces for antennas and telescopes, as well as innovative optical concepts such as photon sieves. Shape adjustment and shape control of these surfaces are described in terms of available technologies and future needs, particularly for the reconfiguration of telecommunications antennas. In summary, the two complementary approaches described and reviewed cover the domain of present and foreseeable space applications. Recent European developments are discussed within a global context and a critical review of the state of the art and recent advances taking into account the reliability and structural stability as design drivers.

SA Based Software Deployment Reliability Estimation Considering Component Reliability of Exponential Distribution

Although many approaches for architecture- based reliability estimation exist, these approaches are typically limited to certain classes or exclusively concentrate on software reliability, neglecting the influence of hardware resources, component reliability, component replica and software deployment. In this paper, a reliability estimation model based on software architecture (SA) is presented. This model incorporates the influence of software deployment, component reliability and component replica. Component lifetimes can be modeled by exponential distribution. The approach of calculating system reliability considering component replica and component reliability is proposed. The influences of different deployment architectures on component reliabilities and system reliability are investigated. The improvement of system reliability by redeployment or component replica is discussed.

SA based software deployment reliability estimation considering component dependence

Reliability is one of the most critical properties of software system. System deployment architecture is the allocation of system software components on host nodes. Software Architecture (SA) based software deployment models help to analyze reliability of different deployments. Though many approaches for architecture-based reliability estimation exist, little work has incorporated the influence of system deployment and hardware resources into reliability estimation. There are many factors influencing system deployment. By translating the multi-dimension factors into degree matrix of component dependence, we provide the definition of component dependence and propose a method of calculating system reliability of deployments. Additionally, the parameters that influence the optimal deployment may change during system execution. The existing software deployment architecture may be ill-suited for the given environment, and the system needs to be redeployed to improve reliability. An approximate algorithm, A*_D, to increase system reliability is presented. When the number of components and host nodes is relative large, experimental results show that this algorithm can obtain better deployment than stochastic and greedy algorithms.

Control of a Space Rigidizable Inflatable Boom Using Macro-fiber Composite Actuators

An experimental investigation of vibration testing and active control of a space rigidizable inflatable composite boom containing embedded piezoelectric composite actuators was conducted. Inflatable deployable space structures offer reduced mass, higher packaging efficiency, lower life cycle cost, simpler design with fewer parts, and higher deployment reliability for many large deployable spacecraft structures applications. Enhancing deployed precision and repeatability for these structures is an ongoing research area, in particular for rigidizable inflatable material systems. In this study, in situ vibration testing and active damping using piezoelectric macro-fiber composite actuators embedded within a typical space-rigidizable deployable composite boom are investigated The embedded macro-fiber composites are shown to be capable of surviving integration, packaging, deployment and thermal rigidization in vacuum, and subsequently operating at their full actuation capability. Positive position feedback controllers using accelerometer, laser vibrometer, and strain gage feedback signals are designed and experimentally evaluated. Velocity-proportional and acceleration-proportional controllers are shown to be capable of attenuating fundamental bending response significantly using only modest control authority (—23dB with 10% of available voltage).

Key technologies for high-accuracy large mesh antenna reflectors

Nippon Telephone and Telegram Corporation (NTT) continues to develop the modular mesh-type deployable antenna. Antenna diameter can be changed from 5 m to about 20 m by changing the number of modules used with surface accuracy better than 2.4 mm RMS (including all error factors) with sufficient deployment reliability. Key technologies are the antenna's structural design, the deployment mechanism, the design tool, the analysis tool, and modularized testing/evaluation methods. This paper describes our beam steering mechanism. Tests show that it yields a beam pointing accuracy of better than 0.1°. Based on the S-band modular mesh antenna reflector, the surface accuracy degradation factors that must be considered in designing the new antenna are partially identified. The influence of modular connection errors on surface accuracy is quantitatively estimated. Our analysis tool SPADE is extended to include the addition of joint gaps. The addition of gaps allows non-linear vibration characteristics due to gapping in deployment hinges to be calculated. We intend to design a new type of mesh antenna reflector. Our new goal is an antenna for Ku or Ka band satellite communication. For this mission, the surface shape must be 5 times more accurate than is required for an S-band antenna.

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.

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.

Validation of a unique concept for a low-cost, lightweight space-deployable antenna structure

Large space-deployable antennas are needed for a variety of applications that include mobile communications, radiometry, active microwave sensing, very-long-baseline interferometry, DoD space-based radar and microspacecraft. Investigators in these fields identify the need for structures up to tens of meters in size for operation from 1 to 90 GHz, based on different aperture configurations. The selection criteria common to all of the users are low cost, lightweight, high reliability and good reflector surface precision. Fortunately, a unique class of space structures has recently emerged that offers great potential for satisfying these criteria. They are referred to as inflatable deployable structures. A good example of such a concept is under development at L'Garde Inc. Serious interest from the user community will depend on realistic demonstrations of the viability of the concept. This means that large, lightweight, low-cost structures need to be developed and used to demonstrate deployment reliability in realistic service environments. The technology data base for the L'Garde inflatable concept will accommodate the development of reflector antenna structures up to 30 m in diameter. Since the concept utilizes very low inflation pressure to maintain the required geometry on orbit, gravity-induced deflection of the structure precludes any meaningful ground-based demonstrations of functional performance. Therefore this concept has been selected for a NASA In-Space Technology Experiment Program (IN-STEP) space-based experiment. The objectives of this experiment are to validate and characterize the mechanical functional performance of a 14-m-diameter inflatable deployable reflector antenna structure in the orbital operational environment. The experiment will be carried by the NASA Spartan spacecraft, which is launched, deployed and recovered by the STS. The Spartan will provide mounting, attitude control, power and data recording for the antenna experiment. The antenna concept development will benefit from both the experiment and supporting technology developments. Results of this experiment are expected to verify the feasibility of fabricating a large space structure for only a few million dollars, demonstrate the reliability of deployment, characterize the quality of the reflector surface and correlate the analytical performance prediction models with actual measured characteristics. Technology developments in support of the experiment, to be conducted at NASA Langley Research Center and the University of Colorado, will include investigation of new and advanced flexible materials, as well as system studies to assess the adequacy of this structural concept for specific classes of applications and for the development of analytical performance production tools. These combined results will be used to advance the technology of the concept with respect to improving surface precision and performance predictability and accommodating larger size structures with different configurations in different orbits.

Deployment reliability predicition for large satellite antennas driven by spring mechanisms

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.

In-step inflatable antenna experiment

Large deployable space antennas are needed to accommodate a number of applications that include mobile communications, earth observation radiometry, active microwave sensing, space-orbiting very long baseline interferometry, and Department of Defense (DoD) space-based radar. The criteria for evaluating candidate structural concepts for essentially all the applications is the same; high deployment reliability, low cost, low weight, low launch volume, and high aperture precision. A new class of space structures, called inflatable deployable structures, have tremendous potential for completely satisfying the first four criteria and good potential for accommodating the longer wavelength applications. An inflatable deployable antenna under development by L'Garde Inc. of Tustin, California, represents such a concept. Its level of technology is mature enough to support a meaningful orbital technology experiment. The NASA Office of Aeronautics and Space Technology initiated the In-Space Technology Experiments Program (IN-STEP) specifically to sponsor the verification and/or validation of unique and innovative space technologies in the space environment. The potential of the L'Garde concept has been recognized and resulted in its selection for an IN-STEP experiment. The objective of the experiment is to (a) validate the deployment of a 14-meter, inflatable parabolic reflector structure, (b) measure the reflector surface accuracy, and (c) investigate structural damping characteristics under operational conditions. The experiment approach will be to use the NASA Spartan Spacecraft to carry the experiment on orbit. Reflector deployment will be monitored by two high-resolution video cameras. Reflector surface quality will be measured with a digital imaging radiometer. Structural damping will be based on measuring the decay of reflector structure amplitude. The experiment is being managed by the Jet Propulsion Laboratory. The experiment definition phase (Phase B) will be completed by the end of fiscal year (FY) 1992; hardware development (Phase C/D) is expected to start by early FY 1993; and launch is scheduled for 1995. The paper describes the accomplishments to date and the approach for the remainder of the experiment.