Devices For Space Applications Research Articles

3D printing of high-stiffness and high-strength glass fiber reinforced PEEK composites by selective laser sintering

Glass fiber reinforced poly-ether-ether-ketone (PEEK) composites are emerging as structural materials of multifunctional devices in space applications, due to their outstanding mechanical properties, electrical insulating properties, and resistance to irradiation. Here, a new approach for preparing glass fiber/PEEK powders tailored for selective laser sintering (SLS) process is proposed. The surface of glass fiber is modified with the sulfonated PEEK following the designed procedure. The flowability of glass fiber/PEEK powders is also improved by adding the nano-scale SiO2 flow agent. The glass fiber reinforced PEEK composites are successfully 3D printed using the glass fiber/PEEK powders. Further, the enhancement of interfacial bonding between PEEK and glass fiber is analyzed through quasi-static tension tests and scanning electron microscopy (SEM) for the SLSed glass fiber reinforced PEEK composites. The average ultimate tensile strength reaches approximately 100 MPa using these optimal process parameters, while the average elastic modulus is around 7 GPa. Finally, the upper limit of fiber weight fraction is evaluated with the X-ray computed tomography (XCT) and the high-fidelity discrete element method (DEM) simulation.

Effects of gamma-ray irradiation on material and electrical properties of AlN gate dielectric on 4H-SiC

This article investigates the radiation effects on as-deposited and annealed AlN films on 4H-SiC substrates under gamma-rays. The AlN films are prepared using plasma-enhanced-atomic-layer-deposition on an n-type 4H-SiC substrate. The AlN/4H-SiC MIS structure is subjected to gamma-ray irradiation with total doses of 0, 300, and 600 krad(Si). Physical, chemical, and electrical methods were employed to study the variations in surface morphology, charge transport, and interfacial trapping characteristics induced by irradiation. After 300 krad(Si) irradiation, the as-deposited and annealed samples exhibit their highest root mean square values of 0.917 nm and 1.190 nm, respectively, which is attributed to N vacancy defects induced by irradiation. Under irradiation, the flatband voltage (V fb) of the as-deposited sample shifts from 2.24 to 0.78 V, while the annealed sample shifts from 1.18 to 2.16 V. X-ray photoelectron spectrum analysis reveals the decomposition of O-related defects in the as-deposited AlN and the formation of Al(NO x ) y compounds in the annealed sample. Furthermore, the space-charge-limits-conduction (SCLC) in the as-deposited sample is enhanced after radiation, while the barrier height of the annealed sample decreases from 1.12 to 0.84 eV, accompanied by the occurrence of the SCLC. The physical mechanism of the degradation of electrical performance in irradiated devices is the introduction of defects like N vacancies and O-related defects like Al(NO x ) y . These findings provide valuable insights for SiC power devices in space applications.

Photoelectrochemical Devices for Oxygen and Fuel Production on Moon and Mars

Human space exploration and the realisation of a green energy economy on Earth are confronted with the same challenge: both require efficient, stable and reliable renewable energy systems.1 Currently existing solutions such as the water electrolyzer in operation on the International Space Station (ISS) for oxygen and hydrogen production are not feasible in future lunar and Martian habitats as they are too bulky and heavy to transport and they lack the required reliability and efficiency2. Photoelectrochemical (PEC) devices not only meet the weight and volume constraints imposed onto devices for space applications by utilising a monolithic design for light absorption, charge separation and catalysis,3 they can also directly be coupled to solar concentrators in order to harvest the abundant solar energy available in space. Despite the advantages, PEC devices are nearly exclusively researched and developed for terrestrial applications and only a very few examples explore the possibility of utilizing the integrated semiconductor-electrocatalyst systems for space applications.4 Here, we present an unprecedented theoretical analysis of the applicability of PEC devices for lunar solar water-splitting and Martian CO2 reduction. These target reactions are in line with roadmaps of international space organisations aiming at a habitat establishment on the lunar South Pole, where water ice is assumed to be present in the Shackleton Crater. Furthermore, the atmosphere on Mars is composed of about 96% gaseous CO2, motivating our choice to investigate Martian CO2 to CO and CH4 conversion.5 Both reaction products could be used as propulsion additives or as precursors for the synthesis of hydrocarbon-based molecules in analogy to terrestrial applications. Firstly, we calculated a refined Martian solar irradiance spectrum and established the theoretical framework to describe PEC devices on Moon and Mars before calculating device limiting efficiencies and expected product rates for realistic devices at different solar irradiance scenarios. Our findings emphasise that PEC devices are indeed applicable on Moon and Mars, particularly when coupled to solar concentrators. In addition, it is evident that gas diffusion electrodes (GDEs), which mark a significant part of CO2 reduction devices investigated terrestrially, are surprisingly not necessarily viable in situations of limited solar irradiance such as present on Mars.References Ross B, Haussener S, Brinkert K. Photoelectrochemical devices for oxygen and fuel production on Moon and Mars. In review. Brinkert K, Mandin P. Fundamentals and future applications of electrochemical energy conversion in space. npj Microgravity 8, (2022).Cheng W-H, et al. Monolithic Photoelectrochemical Device for Direct Water Splitting with 19% Efficiency. ACS Energy Letters 3, 1795-1800 (2018). Brinkert K, et al. Efficient solar hydrogen generation in microgravity environment. Nature Communications 9, (2018). Yoshizaki T, McDonough WF. The composition of Mars. Geochimica et Cosmochimica Acta 273, 137-162 (2020).

The design of a flexible RF generator for driving Acousto-Optical devices in space applications

Acousto-Optical (AO) devices are not only used for filtering purposes in spectral imaging, but also in optical communications and spatial tracking systems. Some AO devices with space applications are AO Tunable Filters (AOTFs), Modulators (AOMs), Deflectors (AODs) and Frequency Shifters (AOFSs). Though these device’s applications differ, they are all controlled with Radio-Frequency (RF) signals. These signals are converted by a transducer into an acoustic wave, which propagates inside the AO device. The interaction between the incoming light and the acoustic waves inside the birefringent AO material creates multiple output beams. This interaction can result in filtering, modulation, deflection or frequency shifting, depending on the AO device in question. This research focuses on the design of a flexible, uniform RF generator, applicable to all AO devices in the space applications domain. The RF output maximizes the performance of the AO device, while the use of components available in space qualified grades eases integration with future space missions. Its design is a key step towards a miniaturized, space qualified, general-purpose RF generator. This research presents schematics, design and preliminary component test results.

Growth and Characterization of Al (111) Thin Film on Piezoelectric Wafers for SAW Device Fabrication for Space Applications

Surface Acoustic Wave (SAW) filters provide precise frequency filtering in RF and IF range with a tiny footprint. Metallic thin films are the essence of such modern SAW filter technology. However, SAW filters realized using NiCr/Al thin films are limited to power levels of ~5 dBm at RF frequencies. This limitation on power level is due to the acousto-migration phenomenon in thin films at higher power levels. In order to enhance the power durability of SAW filters, the preferred oriented growth of Al along (111) crystallographic direction is one of the methods to reduce acousto-migration. This paper explores the growth and characterization of different metallization schemes (NiCr/Al & Ti/Al) on different piezoelectric wafers to achieve oriented Al (111) film growth. Metallic thin films were deposited using electron beam evaporation technique. High Resolution X-Ray Diffraction (HR-XRD) and Four Point Probe Method were used for crystallographic characterization and Sheet Resistance (SR) measurement, respectively. Atomic Force Microscopy (AFM) and surface profiler were used to characterize the surface morphology of the deposited films. FWHM of 4.12 degree of rocking curve on Al (111) peak has been achieved for Ti/Al metal film deposited on ST-X Quartz piezoelectric wafer along with low sheet resistance of 124 mΩ/sq. A deposition rate of 1 Å/s for Ti and 7 Å/s for Al at a deposition temperature of 100 °C gave the best FWHM value for Al (111) orientation on ST-X Quartz wafer. Space qualification tests were also successfully performed on Ti/Al metalized wafers under extreme environmental conditions. The results obtained in this work demonstrate the suitability of Ti as an under layer to grow preferred oriented Al film along (111) orientation and thus to be used in the fabrication of high-power SAW devices for space applications.

Failure rate calculation method for high power devices in space applications at low earth orbit

In this paper we propose that calculation method to evaluate failure rate of high power semiconductor device against proton flux environment of low earth orbit. Advantage of this method is to expand to evaluate failure rate of any devices under various radiation environment. Possible suggestion to improve high power device reliability was discussed.

AM&FT: An Aging Mitigation and Fault Tolerance Framework for SRAM-Based FPGA in Space Applications

Field programmable gate arrays (FPGAs) have become very widely used devices in space applications, and their runtime reconfigurable architecture allows for the area and power acceleration for complex applications. However, FPGAs are increasingly susceptible to aging effects and failures due to harsh space environments and long operation cycles, which reduce the reliability and lifetime of such devices. Although offline aging-aware layout-based methods are effective in aging mitigation, existing studies ignore the fault tolerance needs of the task and the layout strategy will completely fail after a hard failure occurs. This paper presents a reliability framework AM&FT for SRAM-based FPGAs in space applications to support on-chip aging mitigation and fault tolerance. We use an Integer Linear Programming (ILP) model to solve mapping relationships between tasks and reconfigurable blocks (Rbs) in the offline phase to achieve the aging and reliability-aware layout strategy. Second, the ILP model is incorporated into the Design Space Exploration (DSE) to generate a set of layout strategies to tolerate hard faults. Moreover, the state model is used for runtime fault management to handle the impact of different types of faults on the device. Experimental results demonstrate that our framework achieves FPGA on-chip aging mitigation and fault tolerance. Compared with the existing methods, AM&FT can guarantee the fault tolerance requirements of tasks and give priority to guarantee the Quality of Service (QoS) of critical tasks under the condition of hard faults accumulation. In addition, our framework delivers up to [Formula: see text] mean time to failure (MTTF) than the baseline.

Assessment of Proton Direct Ionization for the Radiation Hardness Assurance of Deep Submicron SRAMs Used in Space Applications

Proton direct ionization (PDI) from low-energy protons has been shown to have a potentially significant impact on the accuracy of prediction methods used to calculate the upset rates (URs) of memory devices in space applications for state-of-the-art deep submicron technologies. The general approach nowadays is to consider a safety margin to apply over the UR computed from high-energy proton and heavy-ion experimental data. The data reported here present a challenge to this approach. Different UR prediction methods are used and compared in order to establish the impact of PDI on the total UR. Regardless of the method employed, the findings suggest that PDI can contribute to up to 90% of the total UR, on average, for a general selection of space orbits, with peaks of up to 99%. Such results suggest that an approach based on the characterization of the low-energy portion of the proton spectrum would be more convenient for similar technologies than the application of a general safety margin. Based on data presented here, the previously proposed margin of 5 is exceeded, by large amounts in some cases.

Towards applications, processing and advancements in shape memory alloy and its composites

NiTi’s exotic ability to memorize and regain memorized shape through simple triggers makes it an outstanding material with potential to empower growth of modern applications. Applications in earthquake resilient buildings, biocompatible implants devices and instruments, actuators for aerospace, devices for space applications, sensor and actuators are few to cite. The cost of virgin-NiTi suitable as raw materials for manufacturing devices and articles is the major deterrent in the wide adoptability of such products. Composites with NiTi in powder/fiber and other form as reinforcement exhibit comparable properties to virgin NiTi with additional advantages due to thermal coefficient mismatch and shape memory induced internal stresses. The NiTi based composites are being manufactured by several different routes including casting technology, solid-state based powder metallurgy, hot pressing/roll bonding/friction stir processing and several others. NiTi in powder/fiber/ribbon or even sheet form may be reinforced which distinct advantage of each. Each of these routes have issues and merits typical of the process. It will be a great enabler to unveil prominent characteristics of the processes and products so that merits/limitations relationship can be optimized and maximum benefits can be harnessed. This status report highlights the state of the art on NiTi and NiTi based composites and composite fabrication routes, all in one place so that the relevant stakeholder can be benefited most and the new developments on such topics foster.

Minimal Magnetic Dipole Moment for the Solar Cell Array Using GaInP/GaAs/Ge Cells

The only ambient power source in space is solar energy, which is harvested by photovoltaic conversion with solar cells. Since about 20 years ago, silicon solar cells have been used extensively as the primary power devices in space. However, in recent years, GaInP/GaAs/Ge solar cells with triple junction technology, have been widely used as power-generation devices for space applications. Not only do the GaInP/GaAs/Ge solar cells have better conversion efficiency compared to Si solar cells, but it is also possible to supply the required electric power using a smaller number of solar cells. While there are advantages when using the GaInP/GaAs/Ge solar cells, methods for design of systems of strings should be established for minimizing their magnetic dipole moment. This is because the voltage and current are three times greater than with Si solar cells, and this must be considered. By electromagnetic theory, loop current of a string consisting of cells in series occurs when flowing through it. That magnetic dipole moment can affect attitude control when using magnetic torque bars in orbit, and spacecraft systems require no more than 0.25 Am2 of magnetic dipole moment for optimal attitude control. Therefore, we designed a single string of GaInP/GaAs/Ge solar cells and tested its current capacity to see and minimize the magnetic dipole moment. Finally, we proposed an optimal string design methodology by a test coupon solar cell array using GaInP/GaAs/Ge solar cells by simulation and implemented it on a substrate of carbon fiber reinforced plastic material to see how well the prototype worked or did not work. In future, the string design methodology could be extended to a larger solar cell array by using this coupon design methodology to minimize the magnetic dipole moment.

A Novel Modular Radiation Hardening Approach Applied to a Synchronous Buck Converter

Radiation and extreme temperature are the main inhibitors for the use of electronic devices in space applications. Radiation challenges the normal and stable operation of DC-DC converters, used as power supply for onboard systems in satellites and spacecrafts. In this situation, special design techniques known as radiation hardening or radiation tolerant designs have to be employed. In this work, a module level design approach for radiation hardening is addressed. A module in this sense is a constituent of a digital controller, which includes an analog to digital converter (ADC), a digital proportional-integral-derivative (PID) controller, and a digital pulse width modulator (DPWM). As a new Radiation Hardening by Design technique (RHBD), a four module redundancy technique is proposed and applied to the digital voltage mode controller driving a synchronous buck converter, which has been implemented as hardware-in-the-loop (HIL) simulation block in MATLAB/Simulink using Xilinx system generator based on the Zynq-7000 development board (ZYBO). The technique is compared, for reliability and hardware resources requirement, with triple modular redundancy (TMR), five modular redundancy (FMR) and the modified triplex–duplex architecture. Furthermore, radiation induced failures are emulated by switching all duplicated modules inputs to different signals, or to ground during simulation. The simulation results show that the proposed technique has 25% and 30%longer expected life compared to TMR and FMR techniques, respectively, and has the lowest hardware resource requirement compared to FMR and the modified triplex–duplex techniques.

Experimental and simulation study of the correlation between displacement damage and incident proton energy for GaAs devices

To improve the displacement damage test method for compound semiconductor devices in space applications, the degradation of GaAs devices caused by protons with energy ranging from 50 MeV to 190 MeV was analyzed based on experimental and simulation results. Proton experimental results showed that degradation caused by high-energy proton was less than that caused by low-energy proton. The Geant4 simulation results indicated that the Non-ionizing Energy Loss was dominated by Coulomb scattering at low proton energy. The degradation of GaAs devices were thus more influenced by displacement damage dose induced by Coulomb scattering. The equivalent displacement damage dose induced by Coulomb scattering can be utilized to evaluate displacement damage in GaAs devices intended for space application.

A novel method to hit the limit temperature of Stirling-type cryocooler

The Stirling-type cryocooler with its compact size and high efficiency is always expected to obtain its temperature limit of below 3 K. However, the pressure drop losses caused by high-frequency oscillation create large obstacles for this objective. This paper reports a novel thermal-driven Stirling-type cryocooler to obtain the lowest temperature of a Stirling-type cryocooler. The advantages of a thermal-driven cryocooler (Vuilleumier cryocooler) and pulse tube cryocooler are combined with a new type of cryocooler, called the Vuilleumier gas-coupling pulse tube hybrid cryocooler (VM-PT). A prototype of the VM-PT was recently developed and optimized in our laboratory. By using helium-4 as the working gas and magnetic regenerative materials (HoCu2 and Er3Ni), the lowest temperature of 2.5 K was obtained, which can be regarded as an important breakthrough for the Stirling-type cryocooler to achieve its limit temperature of below 3 K. It can supply >30 mW cooling power at 4.2 K and >500 mW cooling power at 20 K simultaneously. Theoretically, it is feasible to use this VM-PT for cooling the superconducting devices in space applications.

Design and Fabrication of Silicon-on-Silicon-Carbide Substrates and Power Devices for Space Applications

A new generation of power electronic semiconductor devices are being developed for the benefit of space and terrestrial harsh-environment applications. 200-600 V lateral transistors and diodes are being fabricated in a thin layer of silicon (Si) wafer bonded to silicon carbide (SiC). This novel silicon-on-silicon-carbide (Si/SiC) substrate solution promises to combine the benefits of silicon-on-insulator (SOI) technology (i.e device confinement, radiation tolerance, high and low temperature performance) with that of SiC (i.e. high thermal conductivity, radiation hardness, high temperature performance). Details of a process are given that produces thin films of silicon 1, 2 and 5 μm thick on semi-insulating 4H-SiC. Simulations of the hybrid Si/SiC substrate show that the high thermal conductivity of the SiC offers a junction-to-case temperature ca. 4× less that an equivalent SOI device; reducing the effects of self-heating, and allowing much greater power density. Extensive electrical simulations are used to optimise a 600 V laterally diffused metal-oxide-semiconductor field-effect transistor (LDMOSFET) implemented entirely within the silicon thin film, and highlight the differences between Si/SiC and SOI solutions.

Failure rate calculation method for high power devices in space applications at low earth orbit

This paper discusses the universal calculation method for space proton induced failure rate on high power device. High energetic particles can be the reason of power device failure in both terrestrial and space. T-CAD simulation result gives a threshold charge value for the device destruction which is triggered by energetic proton from space. The amount of threshold charge depends on applied voltage for high power device. The probability of charge generation in silicon due to proton penetration is considered as well. This probability function variation depends on the thickness of device and incident energy of proton which studied before at there. Last consideration on this paper is 3.3kV PiN diode's Single Event Upset Cross section and failure rate which was calculated by proposed method in Low earth orbit environment condition.

Power cycling fatigue and lifetime prediction of power electronic devices in space applications

This paper presents a complete study about power cycling stress on space components. Power cycling fatigue is generally studied for traction or automotive applications. But power cycling failures are also a major cause of concern in space industry. In this paper we successively address the following subjects: definition of the power cycling stress in space applications, experimental power cycling test on space components and lifetime prediction for a typical earth observation application.

Multi-scale modeling to investigate the single event effects for space missions

Space environment studies and its effects on electronic systems are fundamental for space applications. More precisely, single event effects (SEE) induced by proton and heavy ions are identified as a major reliability issue for complex electronics systems for decades. The calculations of soft error rates (SER) are still a challenge to obtain the device sensitivity, extrapolate to evolving technologies and investigate the emerging SEE mechanisms. In fact, between the incoming particle and SEE occurrence, many physical mechanisms intervene. Each step has an important role in the SEE occurrence. Methods have been proposed, using combined nuclear codes and device simulations or semi-empirical coupling of nuclear physics and experimental data. During the last 10 years, multi-scale modeling and physics-based Monte-Carlo simulations have been widely developed to overcome the obsolescence of engineering models at predicting SEE rates and investigate sub-micron technology response. More recently, SEE prediction methodologies have been developed aiming at proposing new and adapted approaches for modern electronics in order to investigate the SEE trends induced by the technological roadmap and prevent the problematic emerging SEE. In this work, The Multi-Scale Single Event Phenomena Predictive Platform (MUSCA SEP 3) is used to evaluate the SER trends for modern devices in space applications and more specifically the emergent impact induced by the direct ionization of proton for nanometric devices. We discuss the impact and the significance of each modeling layer in SER analyses and issues, specifically the radiative environment characteristics i.e. the spectrum, the direction properties and the space weather dynamics. These results demonstrate the relevance and the requirement of the multi-scale approach for reliability issues.

High-energy Electron Beam Irradiation of Al-doped ZnO Thin Films Deposited at Room Temperature

(XRD), and X-ray photoelectron spectroscopy results, we suggest that the density of Vo donor defects is decreased due to in-diusion of oxygen from the ambient into the films after HEEBI treatment at low doses up to 10 15 electrons/cm 2 while the opposite phenomenon can occur with further increase in the dose. We also found from the XRD analysis that the worse crystallinity with a smaller grain size was observed in HEEBI-treated AZO films at a higher dose, corresponding to a higher oxygen fraction in the films. We believe that our results will contribute to developing high-quality AZO-based materials and devices for space applications.

Kinetic simulations of a plasma thruster

The modelling of the Hall thruster SPT-100 is a very important issue in view of the increasing importance of such propulsion devices in space applications. Only kinetic models can investigate the rich variety of physical mechanisms involved in the Hall discharge and in the plume emitted from the thruster. This paper collects a number of different particle-in-cell/Monte Carlo collision models which have been able to reveal different phenomena related to the peculiar physics of Hall thruster, such as sheath instability, azimuthal fluctuations and plume backflow.

Innovative packaging solution for power and thermal management of wide-bandgap semiconductor devices in space applications

Devices based on wide-bandgap semiconductors such as SiC or GaN allow high power densities and elevated working temperatures. Here we present an innovative package for high-power electronics, within the framework of an ESA-contracted project. The paper shows the housing concept, design study, materials selection, manufacturing method and first test results. Materials are selected for their high thermal conductivity (TC) and low coefficient of thermal expansion (CTE). Several materials were selected: AlN was selected as substrate material, and novel metal-matrix composites (MMCs) based on Cu–diamond and Cu–vapour grown carbon nanofibres (VGCNFs) were evaluated as heat-sink materials. Subsequently, a complete bonding study between ceramic materials and MMCs was performed. In order to obtain fully dense materials AlN was manufactured by pressureless sintering, while the MMC parts were manufactured by hot-pressing. The MMC powders were obtained by an electroless plating process. Preliminary characterisation of the housing and its parts show encouraging results as a solution for high-power devices working at temperatures up to 300 °C. TC near 500 W/mK and CTEs of around 10 ppm/K have been obtained. These are comparable to the state-of-the-art materials. Out-gassing, thermal cycling and hermeticity tests of the packages were performed. The presented new packaging solutions show great promise for space applications such as high-frequency power amplifiers for satellite communications and for radar transmitters, and have started to generate an interest from commercial space-system manufacturers.