Space Environmental Tests Research Articles

Main Stages and Results of the Development of Mobile Space Environment Simulation Facility “Metamorphosis”

Abstract This article presents the main stages and results of the project “Mobile Space Environment Testing Equipment Development of “Metamorphosis” Prototype for Transportation Intermodal Traffic”. For successful implementation of the project, the project has been divided into four stages: 1) Design calculations and design documentation for the design elements of the prototype; 2) Prototype software development; 3) Manufacturing of construction details and prototype assembly; 4) Industrial research and prototype testing. The goal of the project is, based on industrial research, to develop a prototype of the Mobile Space Environment Test Facility (MSTF) “Metamorphosis” transported in an intermodal environment, and to achieve the level of scientific and technical readiness of MSTF from TRL2 to TRL4 (by the scale of the European Space Agency (ESA)) for further development of the project. This project is unique and has no comparable analogues, as all existing test facilities are stationary. The project is implemented by Riga Technical University in cooperation with Cryogenic and Vacuum Systems Ltd.

Calibration for Space Solar Cells: Progress, Prospects, and Challenges

Space solar cells, have been providing a consistent supply of energy for various spacecraft for decades. Currently, the third‐generation solar cells, such as perovskite solar cells (PSCs) and organic solar cells, have demonstrated significant potential for space applications. However, their real performance in space environments is not yet clear. To assess crucial performance parameters, solar cells need to be calibrated under the standard space spectral irradiance before deployment in space. This is known as AM0 calibration. This review article focuses on the calibration techniques and methods for space solar cells. The topics covered include space environment and standard testing condition for solar cells, the measurements of key parameters for traditional solar cells, advancements in PSCs and organic solar cells for space applications, and a comprehensive review of diverse calibration methods. The discussion spans from near‐ground calibration to near‐space calibration and space calibration, encompassing approaches, key technologies, developmental milestones, and the respective merits of each calibration methods, especially focus on high altitude balloon calibration. Finally, the article addresses the challenges and future trends of space solar cell calibration based on the aforementioned discussions.

Commercial optical coatings in space

The use of commercial optical coatings for space applications for the aptly named “New Space” missions is a state-of-the-art trend. These products are generally less costly and time-consuming in their production and therefore, there is a much wider range of optical coatings available compared to custom-made products. However, the reliability of commercial manufacturing processes is a key concern. Additionally, the resistance of commercial products against space environmental degradation mechanism at operating temperatures needs to be evaluated. In this study, seven commercial products with multi-layer thin film optical coatings consisting of filters, mirrors and windows have been selected from various manufacturers and the results with regards to process verification and space environmental exposure testing are presented. The impact of space environmental effects on the optical performance of the coatings is evaluated, with particular emphasis on the performance at cryogenic temperature. Finally, guidelines and precautions for use of commercial optical coatings for space applications.

Experimental set-up of a thermal vacuum chamber for thermal model in-house correlation and characterization of the HYPSO hyperspectral imager

Space environment with changing temperatures and vacuum can affect the performance of optics instruments onboard satellites. Thermal models and tests are typically done to understand the optics performance within large space projects, but less often in nanosatellites projects. It is even more rarer for an optics payload inside a CubeSat platform, made by a third provider, to do functional tests on their optics during space environment test campaign. In this research, an in-house made vacuum chamber with the possibility to warm up (TVAC) the devices under tests, and wall-through transparency for optics experiments is set-up. In parallel, a thermal model of the HYPerspectral Small satellite for ocean Observation (HYPSO) Hyperspectral Imager (HSI) is developed. The HSI, which is a transmissive grating hyperspectral instrument ranged in the visible to near infrared wavelength, has been tested in TVAC. As thermal control is based on heating the device under test, a new method for fitting the thermal models inside vacuum chambers with only heating capability is proposed. Finally, the TVAC set-up and the thermal model fitting method have been demonstrated to be appropriate to validate the HSI thermal model, and to characterize the optics performance of HSI in vacuum and in the range of temperatures found inside the in-orbit HYPSO-1 CubeSat.

Preparation of white ZrO2 coating with low solar absorptance on aluminum alloy by plasma electrolytic oxidation

The plasma electrolytic oxidation (PEO) coatings with the color of black or white have good prospects in thermal control application. However, it still remains a challenge for obtaining the PEO coatings on Al alloys to achieve high whiteness that in turn could give adequate low absorption thermal control characteristic. Herein, a bright white oxide coating mainly composed of ZrO2 was successfully prepared on 6061 aluminium alloy by PEO process from a fluorozirconate electrolytic solution. The microstructure and composition of the coating were studied by SEM, EDS, XRD and XPS. The thermal control properties were measured by UV-VIS-NIR spectrophotometer and infrared emissivity spectrometer, respectively. The stability of thermal control properties of the coating was also evaluated by simulated space environmental tests. The corrosion protection performances of the coating were investigated by potentiodynamic polarization and salt spray tests. Results show that the oxide coating is composed of t-ZrO2 as well as a little of m-ZrO2 and γ-Al2O3 with a porous microstructure. The coating exhibits low solar absorptance (αs) of 0.205 and high emissivity (ε) of 0.84, which is comparable for the typical space white paints. In addition, the coating owns excellent stability in thermal control properties under simulated space environments. The coating has a good durability in corrosive environment though it provides only slight improvement in corrosion resistance of 6061 aluminium alloy due to the presence of many larger micropores in the coating.

Development of flat absorber black anodic coating on 3D printed Al–10Si–Mg alloy for spacecraft thermal control application

Black anodic coating (BAC) is developed on 3D printed or additively manufactured (AM) Al–10Si–Mg alloy by sulphuric acid based anodization technique at low (∼9 °C) temperature. The microstructural and surface properties of the coating are investigated by optical microscopy (OM), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and water contact angle (WCA) measurement techniques. The solar absorptance and infrared (IR) emittance of the coating have been evaluated in the range 200–2500 nm and 3–30 μm, respectively. Nanoindentation technique is employed with low load to evaluate the hardness and modulus of the coating at microstructural length scale. The anodic coating shows superior hardness (∼3.95 GPa) and modulus (∼96 GPa) as compared to reported literature values, possibly due to dense microstructure and the presence of harder ceramic phases, e.g., alumina and kyanite in anodic coating. Further, due to dense microstructure, corrosion resistance improves significantly after anodization of AM alloy. Finally, thermo-optical properties are not altered after the space environmental tests which ensures the usage of the present anodic coating on AM Al alloy for spacecraft thermal control application. The solar absorptance (0.87) and IR emittance (0.78) obtained for the present coating as flat absorber characteristics are higher than the coatings processed on conventional wrought alloys. The present anodic coating shows substantial improvement in mechanical, thermo-optical and corrosion properties due to higher silicon content unlike conventional wrought alloy and refinement in microstructure during additive manufacturing aiding continuous and uniform anodic oxide layer.

Numerical heat transfer study of a space environmental testing facility using COMSOL Multiphysics

Environmental chambers are used to test the expected performance of space instrumentation and to investigate certain processes which are relevant in space or other planetary environments. In this study, a computational model of an existing Martian experimental facility is investigated numerically using COMSOL Multiphysics. For this purpose, we simulate the near surface water cycle under Martian temperature and pressure experimental conditions as tested inside the chamber and we compare the simulations with the experimental data. The model shows good agreement with experiments on the equilibration time scales and thermal gradients. Due to the imposibility to place sensors at multiple locations inside the chamber, we use the model to extrapolate the one-point relative humidity of the experimental data to each grid points in the simulation. This model gives an understanding of the gradient in atmospheric water relative humidity to which the experimental samples such as deliquescent salts and Martian regolith simulants are exposed at different time intervals. The of the performance of HABIT instrument during the tests, of the ESA/IKI ExoMars 2022 robotic mission to Mars, when compared with the model shows the existence of an extra internal heating source of about 1 W which can be attributed to the hydration and deliquescence of the salts exposed to Martian conditions when in contact with atmospheric moisture. In addition, the presented model is used to predict the thermal gradients and understand the time response when the chamber is heated in vacuum conditions. Our analysis shows that for thermal vacuum tests, the chamber will take about 2.5 h to reach the test temperature of 420 K.

High performance Li-, Na-, and K-ion storage in electrically conducting coordination polymers.

Coordination polymers (CPs) made of redox-active organic moieties and metal ions emerge as an important class of electroactive materials for battery applications. However, the design and synthesis of high voltage alkali-cation reservoir anionic CPs remains challenging, hindering their practical applications. Herein, we report a family of electrically conducting alkali-cation reservoir CPs with the general formula of A2-TM-PTtSA (wherein A = Li+, Na+, or K+; TM = Fe2+, Co2+, or Mn2+; and PTtSA = benzene-1,2,4,5-tetra-methylsulfonamide). The incorporation of transition metal centers not only enables intrinsic high electrical conductivity, but also shows an impressive redox potential increase of as high as 1 V as compared to A4-PTtSA analogues, resulting in a class of organometallic cathode materials with a high average redox potential of 2.95–3.25 V for Li-, Na- and K-ion batteries. A detailed structure – composition – physicochemical properties – performance correlation study is provided relying on experimental and computational analysis. The best performing candidate shows excellent rate capability (86% of the nominal capacity retained at 10C rate), remarkable cycling stability (96.5% after 1000 cycles), outstanding tolerance to low carbon content (5 wt%), high mass loading (50 mg cm−2), and extreme utilisation conditions of low earth orbit space environment tests. The significance of the disclosed alkali-ion reservoir cathodes is further emphasized by utilizing conventional Li-host graphite anode for full cell assembly, attaining a record voltage of 3 V in an organic cathode Li-ion proof-of-concept cell.

(초)소형위성의 New Space 대응 및 산업화 전략

In this paper, the New Space characteristics and response of micro & small satellite, and space industrialization strategy using domestic technologies are described. Recently, micro & small satellites are developed worldwide, including Starlink, having the characteristics of low-cost, light-weight and satellite constellation. Therefore, it is necessary to prepare for the constellation operation by considering the use of Commercial Off-The-Shelf (COTS) parts, satellite weight, shape and mass production. In particular, it is necessary to develop Multi Input Multi Output (MIMO) technology in consideration of the frequency interference during constellation operation, and to prepare and make efforts to secure frequencies in the government. Among the commercial-grade memories of Samsung Electronics and SK Hynix, the space-grade memory field using radiation tolerant memory and the high reliable packaging and space environment test technology has potential as a space industrialization strategy.

Low reflectance of carbon nanotube and nanoscroll-based thin film coatings: a case study.

Research on carbon material-based thin films with low light reflectance has received significant attention for the development of high absorber coatings for stray light control applications. Herein, we report a method for the successful fabrication of stable thin films comprised of carbon nanotubes (CNTs) and nanoscrolls (CNS) on an aluminium (Al) substrate, which exhibited low reflectance of the order of 2–3% in the visible and near-infrared (NIR) spectral bands. Changes in the structural and chemical composition of pristine single-walled carbon nanotube (SWCNT) samples were analyzed after each processing step. Spectroscopy, microscopy and microstructural studies demonstrated emergence of CNS and multi-walled carbon nanotubes (MWCNTs) due to the sequential chemical processing of the sample. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) studies revealed the formation of CNS via curling and folding of graphene sheets. Microstructural investigations including SEM and atomic force microscopy (AFM) confirmed the presence of microcavities and pores on the surface of the film. These cavities and pores significantly contribute to the observed low reflectance value of CNTs, CNS compound films by trapping the incident light. Fundamental space environmental simulation tests (SEST) were performed on the coated films, that showed promising results with reflectance values almost unaltered in the visible and NIR spectral bands, demonstrating the durability of these films as potential candidates to be used in extreme space environmental conditions. This study describes the preparation, characterization, and testing of blended CNT and CNS coatings for low-light scattering applications.

Study on the Development of a Small ETG for the Korean Launch Vehicle’s Low Orbit Test

The Korea Aerospace Research Institute is planning to launch a satellite for the Korea launch vehicle’s low orbit test in 2021. An electrically heated thermoelectric generator (ETG) with a mass of 850 g (small ETG) will be one of its selected payloads for this test flight. To assess and assure the design heritage and the reliability of the ETG in the space environment, a small ETG will be tested at the top of the satellite for more than a year. In this study, the design for a small ETG with 10 W(thermal) of heat input was developed through simulations such as heat transfer analysis, modal analysis, thermoelectric analysis, and structural analysis. Then a mock-up was fabricated and basic performance tests were carried out to be ready for the space environment test.

High-Resolution Image and Video CubeSat (HiREV): Development of Space Technology Test Platform Using a Low-Cost CubeSat Platform

In this paper, we present high-resolution image and video CubeSat (HiREV), the first constructed 6 U platform to reach the space technology test bed stage, developed by the Korea Aerospace Research Institute (KARI). The CubeSat system is a low-cost platform that has been widely applied to various space missions, from missions involving earth observation to deep space. Despite the emergence of the CubeSat technology worldwide, the CubeSat market in Korea is still in the beginning stages, and a standard testing platform is also in demand. For this reason, KARI is starting to develop a 6 U CubeSat platform, which includes a less than 3 U bus system and greater than 3 U payload space. HiREV has been developed with locally manufactured parts, creating a domestic commercial off-the-shelf infrastructure for CubeSat and 3 m resolution camera payload development. Core flight software has also been applied as an on-board flight software system. Presently, we have developed the main system, while HiREV is under space environmental testing.

The ISS-CREAM Silicon Charge Detector for identification of the charge of cosmic rays up to Z = 26: Design, fabrication and ground-test performance

The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is a space-borne mission designed for the precision measurement of the energy and elemental composition of cosmic rays. The Silicon Charge Detector (SCD), placed at the top of the ISS-CREAM payload, consists of 4 layers. Each layer has 2688 silicon pixels and associated electronics arranged in such a fashion that its active detection area of 78.2 × 73.6 cm2 is free of dead area. The foremost goal of the SCD is to efficiently and precisely measure the charge of cosmic rays passing through it. The 4-layer configuration was chosen to achieve the best precision in measuring the charge of cosmic rays within the constraints on the mass, volume and power allotted to it. The amount of material used for its support structure was minimized as well to reduce the chance of interactions of the cosmic ray within the structure. Given the placement of the SCD, its 4-layer configuration and the minimal amount of material in the cosmic-ray trajectory, the SCD is designed to measure the charge of cosmic rays ranging from protons to iron nuclei with excellent detection efficiency and charge resolution. We present the design and fabrication of the SCD as well as its performance during space environment tests which it underwent successfully. We also present its performance in charge measurement using heavy ions in a beam test at CERN, the European Organization for Nuclear Research.

簡易曝露実験装置（ExHAM）を用いた軽量高精度CFRP鏡の長期宇宙曝露実験

簡易曝露実験装置（ExHAM）を用いた軽量高精度CFRP鏡の長期宇宙曝露実験

3-D modeling and finite elements analysis of KM6 motion simulator

As an important part of the satellite space sport simulation system of the KM6 manned spacecraft space environmental test equipment, the satellite motion simulator has the function of simulating and testing the satellites on the ground. In this paper, the 3-D model of the motion simulator is established, and its performance is analysed using finite elements simulation software under different conditions. Under the different conditions of static force and dynamics, the simulation results of the vertical state of the spin axis and tilted 30° state of the spin axis are compared and the optimal working conditions is designed. Modal analysis and buckling analysis are performed to prove that the design of the structure is feasible.

Evaluations of Silica Aerogel-Based Flexible Blanket as Passive Thermal Control Element for Spacecraft Applications

The feasibility of utilizing commercially available silica aerogel-based flexible composite blankets as passive thermal control element in applications such as extraterrestrial environments is investigated. Differential scanning calorimetry showed that aerogel blanket was thermally stable over – 150 to 126 °C. The outgassing behavior, e.g., total mass loss, collected volatile condensable materials, water vapor regained and recovered mass loss, was within acceptable range recommended for the space applications. ASTM tension and tear tests confirmed the material’s mechanical integrity. The thermo-optical properties remained nearly unaltered in simulated space environmental tests such as relative humidity, thermal cycling and thermo-vacuum tests and confirmed the space worthiness of the aerogel. Aluminized Kapton stitched or anchored to the blanket could be used to control the optical transparency of the aerogel. These outcomes highlight the potential of commercial aerogel composite blankets as passive thermal control element in spacecraft. Structural and chemical characterization of the material was also done using scanning electron microscopy, Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy.

The Design of Large Arc-shape High-precision Walking Device in TV (thermal-vacuum) Conditions

The large-sized space environmental simulation test facility is mainly used for providing thermal radiation environment in high-vacuum, cold and dark space for satellites, spacecraft, lunar spacecraft to carry out whole satellite thermal vacuum test and for large equipment like antenna to carry out tests in TV conditions. Monitoring the spacecraft’s surface optical image or temperature is a main task in space environment simulation test. In previous tests, optical image test mainly took place in a fixed position, so the measuring location and angle are limited. This paper focuses on large spherical space environmental simulation test facility, and designs a large arc-shape high-precision walking device in a space environment simulation test device. It introduces key technology in detail like structure design, thermal design, processes and manufacturing, etc. The test results show that this device can work steadily and reliably under simulation space environments, and the precision exceeds 0.5°.

Space qualification and characterization of high emittance black nickel coating on copper and stainless steel substrates

Black nickel coatings exhibiting high infrared emittance were developed on copper and stainless steel substrates by pulse electrodeposition using a modified Fishlock bath. The uniform jet black coating is intended to provide passive thermal control of spacecraft components. Space worthiness of the coating was evaluated by conducting a series of space environmental tests such as humidity, thermal stability, thermal cycling and thermo-vacuum performance tests. The thermo-optical properties namely solar absorptance (αS) and infrared emittance (εIR) of the coatings were measured before and after each environmental test. No significant change in thermo-optical properties was observed after environmental tests showing their high stability for spacecraft thermal control applications. The coatings were characterized by cross-sectional SEM and EDX, XRD, XPS, Nanoindentation and Nano Vision analysis. X-ray diffraction pattern reveals the amorphous nature of the coating with possible presence of ZnS. XPS analysis confirms the chemical and electronic state of the elements. Average modulus and hardness of the coating was recorded using Nanoindentation method and a high resolution 3D image of the surface was generated using Nano Vision scan.

Final payload test results for the RemoveDebris active debris removal mission

Since the beginning of the space era, a significant amount of debris has progressively been generated in space. Active Debris Removal (ADR) missions have been suggested as a way of limiting and controlling future growth in orbital space debris by actively deploying vehicles to remove debris. The European Commission FP7-sponsored RemoveDebris mission, which started in 2013, draws on the expertise of some of Europe's most prominent space institutions in order to demonstrate key ADR technologies in a cost effective ambitious manner: net capture, harpoon capture, vision-based navigation, dragsail de-orbiting.This paper provides an overview of some of the final payload test results before launch. A comprehensive test campaign is underway on both payloads and platform. The tests aim to demonstrate both functional success of the experiments and that the experiments can survive the space environment. Space environmental tests (EVT) include vibration, thermal, vacuum or thermal-vacuum (TVAC) and in some cases EMC and shock. The test flow differs for each payload and depends on the heritage of the constituent payload parts. The paper will also provide an update to the launch, expected in 2017 from the International Space Station (ISS), and test philosophy that has been influenced from the launch and prerequisite NASA safety review for the mission.The RemoveDebris mission aims to be one of the world's first in-orbit demonstrations of key technologies for active debris removal and is a vital prerequisite to achieving the ultimate goal of a cleaner Earth orbital environment.

Space Environmental Testing of Novel Candidate Materials for Multilayer Insulation

Multilayer insulation forms the outer barrier of a satellite towards space. Polymer foils used in multilayer insulation have to withstand the space environment for mission durations often lasting well above 10 years. This paper outlines the space environmental test campaign performed to qualify novel and advanced polymer foils to reduce blanket mass and replace export-controlled materials. Complete multilayer insulation layups were irradiated; these were composed of thicker outermost layers of the reference material Kapton®, a white polyimide and an alternative, conductive black polyimide and up to seven thin internal, aluminized or polyethylene terephthalate and polyethylene naphthalate layers separated by nonwoven spacers. One sample set consisted of polyether-ether-ketone foil and internal vacuum-deposited-aluminum-coated polyether-ether-ketone layers. Materials were exposed to ultraviolet, electrons and protons simulating a 15-year geostationary orbit mission. Absorptance was measured at various stages in situ during the exposures, and emittance was measured ex situ at the beginning and end of the test. With tensile testing, exposure influence on foil mechanical properties was determined and compared with pristine and reference materials. Although the white polyimide was sensitive to ultraviolet and showed strong degradation after ultraviolet and proton exposure, degradation of all other materials was within expected limits and compatible to state-of-the-art foils.