Space Payload Research Articles

Microwave Corona Breakdown Suppression of Microstrip Coupled-Line Filter Using Lacquer Coating

Due to its potential harm to space payload, microwave corona breakdown of microstrip circuits has attracted much attention. This work describes an efficient way to suppress corona breakdown. Since the corona breakdown threshold is determined by the highest electric field intensity at the surface of microstrip circuits, lacquer coating with a thickness of tens of microns is sprayed on top of microstrip circuits. The applied dielectric coating is used to move the discharge location away from the circuit’s surface, which is equivalent to reducing the highest electric field intensity on the interface of solid/air of the circuit and thus results in a higher breakdown threshold. Two designs of a classic coupled-line bandpass filter were used for verification. Corona experimental results at 2.5 GHz show that in the low-pressure range of interest (100 to 4500 Pa), a 5.3 dB improvement of the microwave corona breakdown threshold can be achieved for a filter with a narrowest gap of 0.2 mm, while its electrical performances like insertion loss and Q-factor are still acceptable. A threshold improvement prediction method is also presented and validated.

Design and Experimental Study of a Hybrid Micro-Vibration Isolation System Based on a Strain Sensor for High-Precision Space Payloads.

Micro-vibrations significantly influence the imaging quality and pointing accuracy of high-precision space-borne payloads. To mitigate this issue, vibration isolation technology must be employed to reduce the transmission of micro-vibrations to payloads. In this paper, a novel active-passive hybrid isolation (APHI) system based on a strain sensor is proposed for high-precision space payloads, and corresponding theoretical and experimental studies are implemented. First, a theoretical analysis model of the APHI system is established using a two-degrees-of-freedom system, and an integral control method based on strain sensing is presented. Then, an electromagnetic damper, active piezoelectric actuator, and strain sensor are designed and manufactured. Finally, an APHI experimental system is implemented to validate the effectiveness of electromagnetic damping and strain-sensing active control. Additionally, the control effects of acceleration, displacement, and strain sensors are compared. The results demonstrate that strain sensors can achieve effective active damping control, and the control method based on strain sensors can effectively suppress the payload response while maintaining stability. Both displacement and strain sensors exhibit superior suppression effects compared with the acceleration sensor, with the strain sensor showing greater potential for practical engineering applications than the displacement sensor.

Fully Reconfigurable Photonic Filter for Flexible Payloads

Reconfigurable photonic filters represent cutting-edge technology that enhances the capabilities of space payloads. These advanced devices harness the unique properties of light to deliver superior performance in signal processing, filtering, and frequency selection. They offer broad filtering capabilities, allowing for the selection of specific frequency ranges while significantly reducing Size, Weight, and Power (SWaP). In scenarios where satellite communication channels are crowded with various signals sharing the same bandwidth, reconfigurable photonic filters enable efficient spectrum management and interference mitigation, ensuring reliable signal transmission. Furthermore, reconfigurable photonic filters demonstrate their ability to adapt to the dynamic space environment, withstanding extreme temperatures, radiation exposure, and mechanical stress while maintaining stable and reliable performance. Leveraging the inherent speed of light, these filters enable high-speed signal processing operations, paving the way to various space payload applications, such as agile frequency channelization. This capability allows for the simultaneous processing and analysis of different frequency bands. In this theoretical study, we introduce a fully reconfigurable filter comprising two decoupled ring resonators, each with the same radius. Each resonator can be independently thermally tuned to achieve reconfigurability in both central frequency and bandwidth. The precise reconfiguration of both central frequency and bandwidth is achieved by using the thermo-optic effect along the whole ring resonator path. A stopband rejection of 45 dB, with a reconfigurable bandwidth and central frequency of 20 MHz and 180 MHz, respectively, has been numerically achieved, with a maximum electrical power of 11.50 mW and a reconfiguration time of 9.20 µs, by using the scattering matrix approach, where the elements have been calculated through Finite Element Method-based and Beam Propagation Method-based simulations. This performance makes the proposed device suitable as key building block of RF optical filters, useful in the next-generation telecommunication payload domain.

DEVELOPMENT AND QUALIFICATION OF CNT-CFRP COMPOSITE COMPONENTS FOR SPACE APPLICATIONS

Space payloads are required to be compact, to withstand harsh climatic conditions, and perform well over the duration of a mission. Advanced lightweight materials with low density, high strength, and high specific stiffness, such as carbon fiber reinforce polymers (CFRP), controlled expansion alloy (CE7), and kevlar composites are better suited for space hardware. Despite of having superior mechanical qualities, CFRP composites have limited range of applications due to their worse electrical and thermal conductivities. By adding nano-fillers to improve conductivity, CFRP can be used extensively. The most often employed conductive nano-fillers in CFRP composites are graphene and carbon nanotubes (CNTs). By creating CFRP composites with superior conductivities, the use of CFRP composites can be extended over large applications for space missions. Materials such as aluminum, kovar, invar, and other composites (non-conductive in nature) may be replaced by CFRP-CNT composites. It can be used for fabricating broad variety of satellite hard wares, including satellite panels, reflectors, feed horns, wave guides, carrier plates, electronic package boxes, and covers. Based on tests with different configurations, it was discovered that 0.5% SWCNT offered better mechanical and electrical properties. CNT-CFRP composites are used in the development of carrier plates and reflectors. This article primarily focuses on development of qualification test strategy and how it differs from traditional systems test plan. Results from test coupons and the product level tests were compared and analyzed. The results are acceptable and found better in comparison to their conventional counterparts.

SysML-based Fault Diagnosis Method for Space Payload Systems

SysML-based Fault Diagnosis Method for Space Payload Systems

Performance Evaluation Method for Intelligent Computing Components for Space Applications.

The computational performance requirements of space payloads are constantly increasing, and the redevelopment of space-grade processors requires a significant amount of time and is costly. This study investigates performance evaluation benchmarks for processors designed for various application scenarios. It also constructs benchmark modules and typical space application benchmarks specifically tailored for the space domain. Furthermore, the study systematically evaluates and analyzes the performance of NVIDIA Jetson AGX Xavier platform and Loongson platforms to identify processors that are suitable for space missions. The experimental results of the evaluation demonstrate that Jetson AGX Xavier performs exceptionally well and consumes less power during dense computations. The Loongson platform can achieve 80% of Xavier's performance in certain parallel optimized computations, surpassing Xavier's performance at the expense of higher power consumption.

Design, Simulation, Fabrication and Determining the equivalent circuit Model of a Reconfigurable FSS unit cell filter for electromagnetic protection of space payload systems

Design, Simulation, Fabrication and Determining the equivalent circuit Model of a Reconfigurable FSS unit cell filter for electromagnetic protection of space payload systems

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.

Damage analysis of deployable thin-walled composite shell structure during coiling up

Thin-walled coilable composite shells have been successfully used in deployable space payloads due to their high storage efficiency and stiffness-to-weight ratio. However, in real-life applications the deployable composite shells requiring repeatable coiling up and deployment are easy to be damaged, and their damage or failure behaviors due to large deformations has been rarely studied. This paper aims to investigate their damage and failure behaviors during the snap through, equal-sense and opposite-sense coiling up. First, multiscale models are established to compute the mechanical properties of plain-woven fabrics and unidirectional prepregs with consideration of stiffness reduction of the composites. Then, damages of each ply within the thin-walled shell are studied during snap through and coiling up. Simultaneously, effects of hub diameter on the damage of the thin-walled shell were investigated, followed by experimental verification using strain gauges and a scanning electron microscope (SEM). Simulation and experimental results show that the dominated damage of the thin-walled shell is failure of matrix. The SEMs of the edge damaged show failures of both resin and carbon fibers. Tensile damages of matrix can be relieved as the increment of the hub diameter, and no obvious failure is observed at the hub diameter of 50 mm.

F-IVM: analytics over relational databases under updates

This article describes F-IVM, a unified approach for maintaining analytics over changing relational data. We exemplify its versatility in four disciplines: processing queries with group-by aggregates and joins; learning linear regression models using the covariance matrix of the input features; building Chow-Liu trees using pairwise mutual information of the input features; and matrix chain multiplication. F-IVM has three main ingredients: higher-order incremental view maintenance; factorized computation; and ring abstraction. F-IVM reduces the maintenance of a task to that of a hierarchy of simple views. Such views are functions mapping keys, which are tuples of input values, to payloads, which are elements from a ring. F-IVM supports efficient factorized computation over keys, payloads, and updates. It treats uniformly seemingly disparate tasks: While in the key space, all tasks require general joins and variable marginalization, in the payload space, tasks differ in the definition of the sum and product ring operations. We implemented F-IVM on top of DBToaster and show that it can outperform classical first-order and fully recursive higher-order incremental view maintenance by orders of magnitude while using less memory.

Progress in Lightweight Design Methods for Large-Size Panel Structures in Manned Pressurized Capsules

The pressurized capsule structure provides the pressure environment for astronauts or payloads in space, which is thus considered as the most crucial structural component for manned spacecraft. The manned deep space exploration mission (MDSEM) brings new challenges to the pressurized capsule structure: extremely low structural weight, long service life, reusability and adaptability to the harsh deep space environment. The conventional welded panel pressurized capsule structure (WPPCS) is not able to meet these new requirements. To address the above challenges, this paper comprehensively expounds why the current WPPCS cannot meet the requirements of MDSEMs based on the analysis of the vibration environment and structural characteristics of the pressurized capsule structure. Furthermore, a new type of integrated panel pressurized capsule structure (IPPCS) is proposed, showing the lightweight advantage compared with WPPCS. Finally, the technical details and research results of the strength criterion, design method, material upgrading and structural integrity manufacturing process of the IPPCS are fully introduced. The conclusions drawn in this paper will provide useful and meaningful references for the future development of large-size, lightweight pressurized capsule structures.

On the derivation of inequality constraints for independent component optimization maintaining a minimum system eigenfrequency

The lowest eigenfrequency of a structure depends on the local distributions of stiffness and inertia. When components of a structural system are designed separately, which is typical, e.g., in the aerospace industry, design targets for stiffness and mass of components support independent design work: they can be chosen such that realizing them ensures a minimum system eigenfrequency. However, meeting design targets exactly may be difficult, e.g., due to unforeseen restrictions such as requirements from other disciplines or limitations with respect to manufacturing. This paper uses Rayleigh’s Quotient to derive inequality constraints as limits on the spatial distributions of stiffness and mass, rather than target distributions without tolerance. They serve as component requirements with design freedom and help to decompose the system for independent design.A general formulation based on limit functionals for deformation energy and kinetic energy is proposed for arbitrary structures. For the special case of simply connected systems with rigid interfaces between components and mass-less support elements, limit functionals for support stiffness can be expressed using limit stiffness matrices. A particular choice for them is motivated assuming rigid body motion of the main body. This is then relaxed to produce limit stiffness matrices for arbitrary deformable main bodies.The approach is applied to the structural design of a space payload instrument, the ATHENA Wide Field Imager, enabling independent mass optimization of the so-called primary structure and the support elements. The resulting total mass is 7% larger than the one obtained by monolithic optimization. This could be further reduced to 3% by appropriately adjusting the requirements.

Microfluidic Spontaneous Emulsification for Generation of O/W Nanoemulsions-Opportunity for In-Space Manufacturing.

The use of microfluidics for oil-in-water (O/W) nanoemulsification via spontaneous self-assembly is demonstrated. As this is known to be a longish process, both single- and multicontact microfluidic reactors are tested, the latter providing a longsome, constant microfluidic treatment to maintain advanced phase and interfacial mass transfer. Microfluidic devices provide strong advantages above conventional systems for spontaneous emulsification, with droplet sizes of 62nm at desired surfactant-to-oil ratios (SOR) and a decrease of 90% in process time. Multicontact microfluidics have better performance than their single-contact counterparts, while critical aspects, e.g., process robustness, are also discussed. Ternary phase diagram analysis of the three components (oil, water, surfactant) allow to decide for the right mixing ratio and sequence of mixing steps for the nanoemulsions. Microfluidic spontaneous emulsification meets objective functions of the intended application to provide fortified beverages to astronauts in space exploration. In that viewpoint, an advantage is to achieve stable nanoemulsions at a level of concentrations much higher as compared to application (human intake), allowing a dilution factor to the final product of up to 100. This decreases notably the process time and allows for process flexibility, e.g., to dilute or tailor Earth-prepared nanoemulsion concentrate payloads in space.

Effects of a simulated high-energy space environment on a LaF3/MgF2 multilayer

Due to their low absorption, the LaF3/MgF2 material pair is widely used in the far-ultraviolet space payload. In the space environment, there are plenty of energetic particles (electrons, protons, γ rays, and atomic oxygen) and strong ultraviolet lines. These energetic particles penetrate into the films, and may change the materials’ physical and chemical structures. Hence, these energetic particles and ultraviolet lines may degrade the performance of LaF3/MgF2. We examined the effect of a simulated high-energy space environment on a LaF3/MgF2 multilayer. Dendritic patterns were observed in LaF3/MgF2 multilayer irradiated by the 30 keV electrons. The generation mechanism was proposed. This pattern was gradient wrinkle delamination due to the electric discharge, and it was non-uniform, asymmetric. This problem can be avoided by decreasing the substrate heating temperature and lay number (total thickness), and choosing the fluoride material substrate. The LaF3/MgF2 multilayer demonstrated no changes after the irradiation of the protons, γ rays, atomic oxygen, and ultraviolet lines.

Far ultraviolet mirrors for aurora imaging: design and fabrication.

The emission lines of 140-180nm are auroral bands of N 2 Lyman-Birge-Hopfield, and they have been imaging targets of many satellites that need reflective mirrors. To obtain good imaging quality, the mirrors also should have excellent out-of-band reflection suppression as well as high reflectance at working wavelengths. We designed and fabricated non-periodic multilayer L a F 3/M g F 2 mirrors with working wave bands of 140-160nm and 160-180nm, respectively. We used a match design method and deep search method to design the multilayer. Our work has been utilized in the new wide-field auroral imager of China, and the application of these notch mirrors with excellent out-of-band suppression reduces the utilization of corresponding transmissive filters in the optical system of space payload. Furthermore, our work provides new routes for the design of other reflective mirrors in the far ultraviolet region.

Novel Pointing and Stabilizing Manipulator for Optical Space Payloads

Considering that the Line-Of-Sight (LOS) of a small optical payload is mainly connected with the angular motions while insensitive to linear motion, a novel pointing and stabilizing manipulator was proposed for small payloads on a large spacecraft. By integrating fine and coarse actuators in parallel, the proposed manipulator could isolate spacecraft vibration and independently adjust the LOS on a large scale at the same time. On this basis, the study revealed the key kinematic and dynamic characteristics and then designed an operation scheme, including the large-scale angular motion algorithm and the active isolation algorithm. Finally, the proposed pointing solution was comprehensively verified through simulation.

Combat aircraft as airborne launch platforms for space rockets

PurposeThe purpose of this study was to analyze the possibility of using combat aircraft including decommissioned as a platform for launching and carrying space rockets with satellites (nano and microsatellites). Thus, an airborne-launcher-to-space-system may be attractive to countries without ground-based space rocket launch sites.Design/methodology/approachFor considered launch-to-orbit system configurations, simulations of space rocket effects on aerodynamic characteristics were performed using computational fluid dynamics (CFD ANSYS Fluent) methods. In addition, experimental studies were performed in a wind tunnel to verify the numerical simulations. Discrete models of the aircraft structure were developed for analysis using finite element method (FEM). The analysis of simulated structural properties of the models was carried out to test its stiffness and mass characteristics important for solving the static and dynamic problems of the structure. The validation analyses of aircraft models were based on mass distribution estimation and matching the stiffness properties of the individual airframe structural assemblies.FindingsThe results of numerical analyses and tunnel tests indicate that the influence of carrier rockets on the change of aerodynamic and strength characteristics of the airframe is rather negligible. The aircraft can be used as launching platforms for space rockets. Simulations have indicated that the aircraft will successfully perform a mission of taking away and launching a rocket of at least about 1,000 kg total weight with a 10 kg space payload included.Practical implicationsThe combat aircraft can be used as launch platforms for space rockets, and the air/rocket set can become the equivalent of responsive space assets for countries with small space budgets.Originality/valueThe work presents original results obtained by the authors during a preliminary design of a low-cost satellite launch system consisting of a carrier aircraft and a space rocket orbiter. The possibility of using decommissioned combat aircraft as air-launch-to-orbit platforms was taken into consideration. In the absence of aircraft design documentation, reverse engineering methods and techniques were used to develop aircraft geometry and airframe strength structure. Use of CFD, FEM and simulation methods to evaluate system capabilities was demonstrated. Numerical results from CFD simulations were finally verified in experimental tests.

Characteristics of electron evolution during initial low-pressure discharge stage upon microwave circuits

High-power microwave-induced low-pressure discharges seriously threaten the reliability of space payload systems. Under extremely low-pressure conditions, the evolution of ionized and secondary electrons at the initial stage of discharge is crucial to figure out the discharge process. Therefore, this paper investigates the development of multiple electrons in the discharge process under a highly low-pressure environment using numerical simulation. A three-dimensional simulation model based on the Monte Carlo algorithm is established by considering various electron-gas collisions and secondary electron emissions from different material surfaces. The evolution characteristics of various electrons' populations, energy, and distribution patterns during the discharge process are analyzed. In addition, the influence of the critical conditions at different air pressures on the electron evolution during the discharge process and the intrinsic causes are also investigated. This study is significant in revealing the transition characteristics between multipactor and low-pressure discharge and exploring their inherent mechanisms.

The concept of winged space vehicle marine horizontal landing by docking with ekranoplane

The article makes an overview of possible new means of space payload launching and landing. The possibilities of essential reducing the unit cost of space transportation are described. Both vertical and horizontal versions of the take-off and landing are allowed launching and landing vehicles of different configurations are analyzed by ensuring the reusable application of all elements of the space system, and not just the first stage of the launch vehicle. The advantages of using water areas for space needs are discussed. The opportunities and difficulties of application a heavy ekranoplane (WIG-craft) to assist the marine take-off and landing of an aerospace plane are explained. The flight safety requirements for maneuvering of both these winged vehicles for their reliable approach and docking are analyzed.

Moving Toward an MTT-S Payload in Space: Progress and Status of the MTT-Sat Challenge

The MTT-Sat Challenge is a worldwide competition for teams of undergraduate and graduate students to design and build RF and microwave hardware for small satellites. The main goals of the challenge are to advance space RF and microwave education, inspire students to pursue science and engineering education and careers, and provide tomorrow’s leaders with the interdisciplinary teamwork skills necessary for success.