Effects Of Space Environment Research Articles

Space Environmental Effects on Multifunctional Radiation Shielding Materials

AbstractThe two primary material requirements for a crewed habitat or spacecraft to operate beyond low earth orbit (LEO) include effective radiation shielding against the space radiation and secondary neutron environment and sufficient structural and thermal integrity. In this context it is mandatory to study the effect of long duration space environment on any proposed multifunctional radiation shielding material. In this paper we discuss two radiation shielding composite architectures and their long duration performance in LEO. Samples were flown on NASA's The Materials International Space Station Experiment (MISSE) platform and their structural, optical, and radiation shielding capabilities were characterized pre and post flight. Results showed composite architecture can be key in determining expected damage irrespective of sample placement orientation on the space station. A surface layer with a protective or sacrificial coating can be instrumental in minimizing property degradation even when exposed to orientations with high estimated sun hours and high fluence of atomic oxygen.

Thermal Control Coatings Flown on Low Earth Orbit Materials Experiments

Coatings developed by AZ Technology were exposed to the space environment on two different platforms and analyzed for optical property changes. These coatings were primarily for passive thermal control, but electrostatic dissipative coatings and marker coatings were also flown. Some materials were flown on the Materials on International Space Station Experiment (MISSE) 15th and 16th flights, and some were flown on the Materials Exposure and Technology Innovation in Space (METIS) first flight. The MISSE and METIS flights were both in low Earth orbit but had very different results. Space environmental and molecular contamination effects on optical properties are reviewed. Future experiments, including the Regolith Adherence Characterization flight to the moon, are discussed.

Durability of Passive Thermal Control Materials Exposed to Low-Earth-Orbital Environment

Spacecraft components for passive thermal control need to resist degradation in the space environment. The Materials on International Space Station Experiment (MISSE) 11th and 15th flights and the Materials Exposure and Technology Innovation in Space 1st and 2nd flights exposed a variety of materials to the low-Earth-orbital environment. Materials analyzed in this effort include thermal control coatings with ceramic or silicone binders, components for multilayer insulation blankets, and chemical conversion coatings per MIL-DTL-5541. Space environmental and molecular contamination effects on optical properties are reviewed. Future MISSE experiments are discussed.

Orbit-attitude-structure-thermal coupled modelling method for large space structures in unified meshes

Large space structures would exhibit orbit-attitude-structure-thermal coupled effects in complicated space environment. Thus, a new thermal-structure coupled modelling method is proposed using gradient-deficient absolute nodal coordinate formulation beam elements. Compared to the previous methods, both axial and circumferential heat conduction are considered. The cubic interpolation in temperature field instead of the linear interpolation is adopted to obtain a unified-mesh temperature-displacement description. The gravitational force and gravity gradient are modelled, and the effects of attitude motion and structural deformation on solar radiation intensity are considered. In addition, three kinds of quasi-static thermal-structure coupled models are proposed based on Euler-Bernoulli beam theory. Based on the quasi-static models, the theoretical formulas are derived to effectively predict the thermally induced vibrations of the beam in space. Four numerical examples are studied to validate the proposed models, including the heat conduction examples with three boundary conditions and a thermal-structure coupled cantilever beam example. Based on the proposed formulation, the orbit-attitude-structure-thermal coupled dynamics of a multibody system consisted of a rigid body and a large flexible appendage is investigated considering the gravity gradient, solar radiation, Earth's shadow, and self-shadow.

Effect of the LEO space environment on the functional performances of shape memory polymer composites

For the first time, shape memory polymer composites (SMPCs) have been exposed in LEO environment by the MISSE-FF platform: two carbon-fiber reinforced laminates with an SMP interlayer were retrieved after 1 year of exposure, and tested on Earth. Microscopy, DSC, FTIR and mechanical tests were carried out on flight and backup samples. Results show that flight samples behaved differently, because of their different orientation on MISSE-FF. The applied deformed shape was partially recovered on the sample with zenith orientation during its exposure, but both flight samples did not show any additional shape recovery on-Earth. The other sample, with wake orientation, froze the non-equilibrium shape permanently.

CME Arrival Time Prediction via Fusion of Physical Parameters and Image Features

Coronal mass ejections (CMEs) are among the most intense phenomena in the Sun–Earth system, often resulting in space environment effects and consequential geomagnetic disturbances. Consequently, quickly and accurately predicting CME arrival time is crucial to minimize the harm caused to the near-Earth space environment. To forecast the arrival time of CMEs, researchers have developed diverse methods over the years. While existing approaches have yielded positive results, they do not fully use the available data, as they solely accept either CME physical parameters or CME images as inputs. To solve this issue, we propose a method that extracts features from both CME physical parameters and CME images and uses the attention mechanism to fuse the two types of data. First, we design a parameter feature extraction module that extracts features from CME physical parameters. After that, we adopt an effective convolutional neural network model as our image feature extraction module for extracting features from CME images. Finally, utilizing the attention mechanism, we present a feature fusion module designed to fuse the features extracted from both parameters and images of CMEs. Therefore, our model can fully utilize and combine physical parameters and image features, which allows it to capture significant and comprehensive information about CMEs.

Evaluation of the astrometric capability of Multi-Channel Imager and simulated calculation of proper motion of M31

Introduction: The Multi-Channel Imager (MCI), one of the back-end modules of the future China Space Station Telescope (CSST), is designed for high-precision spacebased astronomical observations. This paper evaluates the astrometric capability of the MCI based on simulated observational images and Gaia data: the M31 galaxy is selected as a representative case to validate the astrometric capability by calculating the proper motions (PMs) of the M31 member stars.Method: We analyze the stellar centroids of the simulated images in the R, I and G bands, positional uncertainty of 2.5 mas for brighter foreground reference stars from the Gaia DR3 catalog and of 7.5 mas for the fainter M31 member stars, are adopted respectively. The theoretical PMs are generated from the adopted velocity field model, rotation curve, and stellar surface density profile. And the simulated observed PMs are generated from the aforementioned position uncertainties and theoretical PMs.Result: We conclude that the precision of the MCI derived PMs strongly depends on the number of astrometric epochs per year. Specifically, uncertainty of 10 μas/yr is achievable with 10 epochs per year, and of 5 μas/yr with 50 epochs ignoring possible systematic effects. And symmetrically distributed observed fields yield better M31 kinematic parameters.Discussion: Unknown systematic errors, space environment effects on detectors, dithering strategies, and observation schedules can affect the PMs of M31, the above issues need further analysis and validation in future work.

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.

Evaluation of Microlenses, Color Filters, and Polarizing Filters in CIS for Space Applications.

For the last two decades, the CNES optoelectronics detection department and partners have evaluated space environment effects on a large panel of CMOS image sensors (CIS) from a wide range of commercial foundries and device providers. Many environmental tests have been realized in order to provide insights into detection chain degradation in modern CIS for space applications. CIS technology has drastically improved in the last decade, reaching very high performances in terms of quantum efficiency (QE) and spectral selectivity. These improvements are obtained thanks to the introduction of various components in the pixel optical stack, such as microlenses, color filters, and polarizing filters. However, since these parts have been developed only for commercial applications suitable for on-ground environment, it is crucial to evaluate if these technologies can handle space environments for future space imaging missions. There are few results on that robustness in the literature. The objective of this article is to give an overview of CNES and partner experiments from numerous works, showing that the performance gain from the optical stack is greater than the degradation induced by the space environment. Consequently, optical stacks can be used for space missions because they are not the main contributor to the degradation in the detection chain.

Self-healing polymers for space: A study on autonomous repair performance and response to space radiation

One of the main challenges of space exploration is to properly protect astronauts from the hazards of the space environment. Space suits were hence created to protect crewmembers during extravehicular activities, but they are currently unable to properly withstand damage after, for example, impacts with micrometeoroids and orbital debris (MMOD), and they would depressurize and collapse if punctured, with catastrophic consequences. In this context, the possibility of integrating self-healing materials into spacesuits has drawn the attention of the scientific community, as it would lead to autonomous damage restoration and subsequently increased safety and operational life. Nevertheless, the effects of space environment on these materials are still to be determined and could lead to a significant decrease of their overall performance.The here presented study focuses on a first example of application to a space suit, analyzing the healing performance of a set of candidate self-healing polymers before and after exposure to simulated space radiation. A comparison of bilayers and nanocomposites having these polymers as matrices is also made in the non-irradiated case. This research also aims at filling the gap between standard characterization of self-healing materials (e.g.: scratch, impact, and puncture tests) and assessment of the effects of space radiation on them by combining these two aspects. Understanding if and how radiation can affect damage recovery performance is in fact fundamental to determine whether a given self-healing material can actually be used for space applications.The self-healing response is assessed through in-situ flow rate measurements after puncture damage. Maximum and minimum flow rate, the time between them and the air volume lost within the 3 min following puncture are collected as healing performance parameters. For the neat materials, the same tests are then repeated on gamma-ray irradiated samples to study the variation in self-repairing performance after exposure to simulated space radiation. Results show that the healing performance is higher in systems with lower viscous response and that it decreases after irradiation. A further analysis of the effects of space environment on the presented materials is hence required.The NASA HZETRN2015 (High Z and Energy TRaNsport, 2015 version) software is also used to simulate the action of galactic cosmic rays on the space suit during extravehicular activity. The classic suit multilayer is compared with configurations in which the standard bladder is replaced with a layer of each analyzed material to identify the most promising candidates and determine whether the addition of nanofillers significantly increases the shielding ability.

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.

Overview of the Demonstration and Science Experiments (DSX) Mission

AbstractThe Air Force Research Laboratory's Demonstration and Science Experiments (DSX) mission investigated wave‐particle interactions and the particle and space environment in Medium Earth Orbit (MEO) from June 2019 to May 2021. Its Wave‐Particle Interactions Experiment conducted over 1,300 active high power very low frequency transmissions in the radiation belts providing observations of antenna performance and signal propagation from a controlled source. This included hundreds of transmissions while in magnetic conjunction with other satellites. The Loss Cone Imager and Space Weather Experiment suite observed electron and proton populations over a wide energy range, with several of these instruments providing pitch‐angle resolution. The Space Environmental Effects Experiment investigated effects of the MEO environment on electronics and materials. The Adaptive Controls Experiment demonstrated technology for on‐board identification and control of large structure vibrational modes. We describe the DSX instrument capabilities and on orbit performance, science planning and operations for carrying out an array of active and passive experiments, and some initial results in brief. We also describe plans for further work and data release.

Bacterial Virulence and Prevention for Human Spaceflight.

With the advancement in reusable rocket propulsion technology, space tourist trips into outer space are now becoming a possibility at a cost-effective rate. As such, astronauts will face a host of health-related challenges, particularly on long-duration space missions where maintaining a balanced healthy microbiome is going to be vital for human survival in space exploration as well as mission success. The human microbiome involves a whole list of micro-organisms that reside in and on the human host, and plays an integral role in keeping the human host healthy. However, imbalances in the microbiome have been directly linked to many human diseases. Research findings have clearly shown that the outer space environment can directly affect the normal microbiome of astronauts when the astronaut is exposed to the microgravity environment. In this study, we show that the simulation of microgravity on earth can mimic the outer space microgravity environment. Staphylococus aureus (S. aureus) was chosen for this study as it is an opportunistic pathogen, which is part of the normal human skin microflora and the nasal passages. This study's results show that S. aureus proliferation was significantly increased under a microgravity environment compared to Earth's gravity conditions, which complements previous work performed on bacteria in the outer space environment in the International Space Station (ISS). This demonstrates that this technology can be utilised here on Earth to mimic the outer space environment and to study challenging health-related questions. This in return saves us the cost on conducting experiments in the ISS and can help advance knowledge at a faster rate and produce countermeasures to mitigate the negative side effects of the hostile outer space environment on humans.

Space Environment Effects on the Electron Yields of Thermal Control Coatings

Space-environment-induced degradation of white thermal control coatings from the Long Duration Exposure Facility (LDEF) was investigated. Much of the exterior of the LDEF was painted with a white thermal control coating, Aeroglaze A276; and most of the interior was coated with a black thermal control coating, Aeroglaze Z306. Outgassing from these coatings and other LDEF materials interacted with the white surface when exposed to sunlight after volatile materials condensed on the LDEF surfaces. Surface morphology was characterized by optical and scanning electron microscopies. Fourier-transform infrared spectroscopy and energy-dispersive x-ray spectroscopy were used to identify the chemical compounds and elements present in the contamination film. Many material properties were modified due to the prolonged approximately six year low-Earth-orbit exposure, but electron yield (EY) was the focus of this study due to its dominance in spacecraft charging. Measurements showed an increase in maximum EY with increased contamination, with the maximum EY more than doubling in some cases. The NASA Charging Analyzer Program simulations for simplified models of the LDEF showed the impact of the degradation on spacecraft charging under different environmental conditions; equilibrium surface potentials varied by more than 100% in some cases.

An outlier detection method with CNN for BeiDou MEO moderate-energy electron data

Abstract BeiDou Medium Earth Orbit moderate-energy electron detection data play an important role in space environment effect analysis including satellite anomaly diagnosis, satellite risk estimation, etc. However, the data contain outliers which cause obstacle for the subsequent usage significantly. To solve this problem, we propose an outlier detection method based on convolutional neural networks (CNNs) which can learn a rule from labeled historical data and detect outliers from the detection data. With this method, we can identify outliers and do some follow-up operations to improve the data quality. In comparison with general methods, this CNN method provides a more reliable and rapid way to build dataset for the follow-up work.

Effects of vacuum thermal cycling, ultraviolet radiation and atomic oxygen on the mechanical properties of carbon fiber/epoxy shape memory polymer composite

The use of shape memory polymer composites as novel materials for next generation space deployable structures requires the study of the effect of space environment upon their properties. The resistance of carbon fiber/epoxy shape memory polymer composite to vacuum thermal cycling, ultraviolet radiation and atomic oxygen has been evaluated separately by using ground-based simulation facilities. The thermal cycling condition has a temperature range of −100 °C to +100 °C with cycle times of 0, 15, 30, and 45. The irradiation times of ultraviolet with a wavelength range of 250 nm–400 nm are 0, 80, 160, and 240 h. The atomic oxygen radiation has a translational energy of about 5 eV and a flux of about 2 × 1015 atoms/cm2 at the sample position, and the irradiation times are 0, 33, 66, and 100 h. The shape memory polymer composite specimens are compared in terms of morphology, tensile modulus, breaking strength and elongation at break before and after irradiation. Results show that thermal cycling increases tensile modulus but decreases the breaking strength and the elongation at break of material after 45 cycles. The effect of ultraviolet radiation on mechanical properties of materials depends on the radiation dose received. Atomic oxygen can negatively but slightly affect the mechanical properties of the material.

The Vitality of Public Space and the Effects of Environmental Factors in Chinese Suburban Rural Communities Based on Tourists and Residents

The vitality of public space in rural communities is an important symbol of rural revitalization, especially in suburban rural communities. Previous studies focused on rural industries and ignored the effects of the spatial environment on different groups of people. Hence, this study takes the public space of suburban rural communities as an example and uses Global Positioning System (GPS) and cognitive mapping data to establish a new vibrancy assessment system for tourists and residents, respectively. The effects of the public space environment and space vitality in suburban rural communities are revealed through ordinary least squares (OLS) and geographically weighted regression (GWR) models. The results suggested that: (I) There were pronounced seasonal changes and spatial distribution differences in the space vitality of tourists, while residents were concentrated in fixed public spaces. (II) For tourists, the public space vitality in rural communities was affected by seven factors, including accessibility, seats, green looking ratio, recreational facilities, water area, plant species richness, and plant color composition. Green looking ratio and water area had a negative impact. For residents, the public space vitality in rural communities was affected by five factors, including shelter facilities, seats, accessibility, space type, fitness facilities. Only fitness facilities had a negative effect. Our research proposed a feasible and effective method to assess the vitality of rural public space in rural communities, and the finding from this study provides significant implications for the development and planning of suburban rural communities oriented by vitality.

Application of interactive Genetic Algorithm in landscape planning and design

In order to improve the design effect of garden landscape space environment and optimize the structure of garden landscape space environment, an optimization design method of garden landscape space environment based on interactive genetic algorithm was proposed. Landscape space environment design is built with image visual feature space distributed monitoring model and fuzzy pixel area feature fusion reconstruction model, and the landscape space environment design of the image by multistage decomposition and pixel gray characteristics, established landscape space environment design image visual feature reconstruction model. The method also combines block area template matching method is landscape space environment design of the image features visual reconstruction and visual space distributed detection, information fusion using similarity model reconstructs the landscape space environment design of image visual perception process of information fusion, in order to extract fuzzy characteristic landscape space environment design of the image, Finally, interactive genetic algorithm is used to realize the quality assessment of landscape art information fusion perception and visual reconstruction. The simulation results show that compared with the traditional method, the visual reconstruction quality of landscape spatial environment design image processed by this method is better, the image recognition accuracy is higher, and the output signal-to-noise ratio is improved by 14.6%. The experimental results prove that the introduction of interactive genetic algorithm in landscape planning and design can effectively solve the problems of multi-level feature decomposition and pixel feature separation in the process of landscape design, optimize the landscape spatial environment structure, and achieve good landscape spatial environment design effect.

Understanding lifetime and dispersion of cough-emitted droplets in air.

To understand the exact transmission routes of SARS-CoV-2 and to explore effects of time, space and indoor environment on the dynamics of droplets and aerosols, rigorous testing and observation must be conducted. In the current work, the spatial and temporal dispersions of aerosol droplets from a simulated cough were comprehensively examined over a long duration (70min). An artificial cough generator was constructed to generate reliably repeatable respiratory ejecta. The measurements were performed at different locations in front (along the axial direction and off-axis) and behind the source in a sealed experimental enclosure. Aerosols of 0.3-10µm (around 20% of the maximum nuclei count) were shown to persist for a very long time in a still environment, and this has a substantial implication for airborne disease transmission. The experiments demonstrated that a ventilation system could reduce the total aerosol volume and the droplet lifetime significantly. To explain the experimental observations in more detail and to understand the droplet in-air behaviour at various ambient temperatures and relative humidity, numerical simulations were performed using the Eulerian-Lagrangian approach. The simulations show that many of the small droplets remain suspended in the air over time instead of falling to the ground.

The Effect of Space Environment on Sensory and Motor Systems of Astronauts and Space Motion Sickness

İnsanlar, antik çağlardan beri gökyüzüne büyük ilgi göstermişlerdir. Bu ilgili orta çağdan sonra bilimsel temellere dayalı gözlemlere dönüşmüştür. En nihayetinde 20 yy. ortasından itibaren insanlar, bu ilgiyi uzaya yolculuk etmek şeklinde geliştirmişlerdir. İlk olarak, alçak dünya yörüngesi daha sonra ay olmak üzere önemli görevler yerine getirilmiştir. Günümüzde hedeflenen ise Mars’a insanlı görevlerin gerçekleştirmektir. Ancak uzay, düşük yerçekimi (mikrogravite) ve iyonize radyasyon gibi zorlukları sahiptir. Ayrıca uzay araçları da (Uluslararası uzay istasyonu-ISS da dahil) kısıtlı bir alana mahkûm olma, izolasyon, aile ve sosyal çevreden ayrı kalma gibi zorlukları da beraberinde getirmektedir. Tüm bu zorluklar, kaçınılmaz olarak insan fizyolojisi ve psikolojisini önemli ölçüde etkilemektedir. Bu derleme çalışması, uzay ortamının astronotların duyusal ve motor sistemleri üzerine nasıl etki ettiğini irdeleyebilmek ve astronotların sıkça karşılaştığı bir hastalık olan uzay hareket hastalığının ne olduğunu kısaca açıklayabilmek üzere hazırlanmıştır.