Satellite Charging Research Articles

PINE-RT: An operational real-time plasmasphere model

The plasmasphere is a region of cold and dense plasma around the Earth, corotating with the Earth. Its plasma density is very dynamic under the influence of the solar wind and it influences several processes such as the GPS navigation, the surface charging of the satellites and the propagation and growth of plasma waves. In this manuscript, we present a new machine-learning model of the equatorial plasma density depending only on the Kp index and the solar-wind properties at the L1 Lagrange point. We call this model PINE-RT as it has been inspired by the recently-introduced PINE (Plasma density in the Inner magnetosphere Neural network-based Empirical) model and it has been developed to run in real-time (RT) in the context of the PAGER project. This project is an EU Horizon 2020 project aiming at forecasting the threats of satellite charging as a consequence of the solar activity 1–2 days ahead. In PAGER, the Kp index and the solar-wind properties at L1 are the inputs which are made available for the plasmasphere modeling. We report here the detailed derivation of the PINE-RT model and its validation and comparison with two state-of-the-art machine-learning and physics-based models. The model is currently running in real-time and its predictions are publicly available.

Fluctuation of Satellite Charging in the Low Earth Orbit Regime due to Interaction with Ionospheric Plasma

Low Earth-orbiting satellites will always interact with the ionospheric plasma, leading to disruption of satellite operations, depending on the impact of the interaction. Under normal circumstances (without interference), the magnitude of the fluctuation in satellite charging is less than 5V (negative). Any disturbance from charged particles will cause the satellite to experience a more drastic voltage drop of the order of a few hundred volts (negative). The identification of fluctuations in satellite charging is carried out by reviewing the space conditions around the satellite, characterized by several parameters such as density, energy, and plasma temperature, as well as the saturation density of the satellite. To strengthen the analysis, this study deepens the flux changes with an energy of the order of MeV along the satellite orbit. The results of the study show that several low-earth orbit satellites experience a fairly high saturation density, which is correlated with fluctuations in electron flux in some regions traversed by the satellite, such as the polar and the SAA regions. The results confirm that the two regions could be a danger zone for both polar and equatorial satellites.

Modelling the interaction of multicomponent plasma with a CubeSat 1U microsatellite by the molecular dynamics method

The results of modeling the interaction of a multicomponent thermal cosmic plasma consisting of oxygen ions, hydrogen and electrons with a charged CubeSat 1U microsatellite are considered. For the simulation was used method of molecular dynamics. The characteristic features of the spatial distribution of hydrogen and oxygen ions are considered. Near a positively charged spacecraft, there is a region of negative charge, which eliminate a satellite charge. Behind the satellite is the region of the “ion shadow” in which the concentration of ions is close to zero. The spatial features of the “ion shadow” depend on the type of ion, the temperature of the plasma, the velocity and charge of the satellite relative to the plasma. The process of formation of an “ion shadow” for a number of parameters is considered.

Simulating the charging of electric vehicles by laser

At present, wired and wireless charging methods for electric vehicles (EVs) have a number of drawbacks including short charging ranges and long charging times. Laser power transfer (LPT) is a wireless power transfer technique which can be used for UAV (unmanned aerial vehicle) and satellite charging. Recent developments in photovoltaic cells and laser technology allows the transfer power using light which might overcome many of the issues related with other charging methods. In this paper, we describe the design and implementation (in MATLAB) of a novel, high-power charging method using a laser (monochromatic light) to charge electric vehicles. The paper examines the overall efficiency of the LPT for a various input power-level. In addition, it also examines the safety and the possible charging infrastructure for LPT technology. Using this technique, we believe that an overall efficiency of 10-37% can be achieved using existing technology.

Coulomb tether double-pyramid formation, a potential configuration for geostationary satellite collocation

This paper proposes the Coulomb tether double-pyramid satellite formation, which includes a cluster of charged satellites repelling each other by Debye-shielded Coulomb forces and two counterweights connecting to each satellite via elastic massless tethers. The center of mass of the formation is prescribed to move along the geostationary orbit. The equations of motion of the formation are obtained by using Lagrange's equation. Analytical individual satellite charges are derived for the spinning and non-spinning three-satellite configurations, respectively. When the number of satellites is more than three, approximate analytical charges are obtained. Numerical simulations indicate that the proposed formation may be successfully applied to the geostationary satellite collocation in the future.

Realistic Worst Case for a Severe Space Weather Event Driven by a Fast Solar Wind Stream.

Satellite charging is one of the most important risks for satellites on orbit. Satellite charging can lead to an electrostatic discharge resulting in component damage, phantom commands, and loss of service and in exceptional cases total satellite loss. Here we construct a realistic worst case for a fast solar wind stream event lasting 5 days or more and use a physical model to calculate the maximum electron flux greater than 2 MeV for geostationary orbit. We find that the flux tends toward a value of 106 cm−2·s−1·sr−1 after 5 days and remains high for another 5 days. The resulting flux is comparable to a 1 in 150‐year event found from an independent statistical analysis of electron data. Approximately 2.5 mm of Al shielding would be required to reduce the internal charging current to below the National Aeronautics and Space Administration‐recommended guidelines, much more than is currently used. Thus, we would expect many satellites to report electrostatic discharge anomalies during such an event with a strong likelihood of service outage and total satellite loss. We conclude that satellites at geostationary orbit are more likely to be at risk from fast solar wind stream event than a Carrington‐type storm.

Satellite-based In-situ Monitoring of Space Weather: KSEM Mission and Data Application

Many recent satellites have mission periods longer than 10 years; thus, satellite-based local space weather monitoring is becoming more important than ever. This article describes the instruments and data applications of the Korea Space wEather Monitor (KSEM), which is a space weather payload of the GeoKompsat-2A (GK-2A) geostationary satellite. The KSEM payload consists of energetic particle detectors, magnetometers, and a satellite charging monitor. KSEM will provide accurate measurements of the energetic particle flux and three-axis magnetic field, which are the most essential elements of space weather events, and use sensors and external data such as GOES and DSCOVR to provide five essential space weather products. The longitude of GK-2A is 128.2° E, while those of the GOES satellite series are 75° W and 135° W. Multi-satellite measurements of a wide distribution of geostationary equatorial orbits by KSEM/GK-2A and other satellites will enable the development, improvement, and verification of new space weather forecasting models. KSEM employs a service-oriented magnetometer designed by ESA to reduce magnetic noise from the satellite in real time with a very short boom (1 m), which demonstrates that a satellite-based magnetometer can be made simpler and more convenient without losing any performance.

A polarizable MARTINI model for monovalent ions in aqueous solution.

We present a new polarizable coarse-grained martini force field for monovalent ions, called refIon, which is developed mainly for the accurate reproduction of electrostatic properties in aqueous electrolyte solutions. The ion model relies on full long-range Coulomb interactions and introduces satellite charges around the central interaction site in order to model molecular polarization effects. All force field parameters are matched to reproduce the mass density and the static dielectric permittivity of aqueous NaCl solutions, such that experimental values are well-reproduced up to moderate salt concentrations of . In addition, an improved agreement with experimentally measured ionic conductivities is observed. Our model is validated with regard to analytic solutions for the ion distribution around highly charged rod-like polyelectrolytes in combination with atomistic simulations and experimental results concerning structural properties of lipid bilayers in the presence of distinct salt concentrations. Further results regarding the coordination numbers of counterions around dilute poly(styrene sulfonate) and poly(diallyldimethylammonium) polyelectrolyte chains also highlight the applicability of our approach. The introduction of our force field allows us to eliminate heuristic scaling factors, as reported for previous martini ion models in terms of effective salt concentrations, and in consequence provides a better agreement between simulation and experimental results. The presented approach is specifically useful for recent martini attempts that focus on highly charged systems-such as models of DNA, polyelectrolytes or polyelectrolyte complexes-where precise studies of electrostatic effects and charge transport processes are essential.

Comparison between Surface Charging Event from MICHIBIKI (QZS) Satellite and Space Environment Data from Global MHD Simulation

Space environment in geospace changes depending on the solar wind and high energy particles originated from the Sun. It is well known that the satellite anomaly sometimes occurred because of the dynamical variations of the space environment. To understand the current and future conditions of space environment, which we call 'Space Weather Forecast', is one of the quite important activities for safety and security operations of the spacecraft. On the other hand, the detailed information of spacecraft anomaly, possibly related to space disturbances, cannot be available in usual. The risk of the individual satellite depends not only on the space environment, but also on the satellite charging condition, which depend on the structure and materials of the satellite body. Therefore, it is not easy for the satellite operator to judge the risk of the satellite based on the space environment information only. To improve this situation, we start developing specialized information for the nowcasting and forecasting space environment for each satellite, and estimate the risk of satellite anomaly by combining information of space environment and that of satellite materials with a charging model. To seek this approach, the risk of satellite charging will be estimated based on the prediction of space environment using the case study of MICHIBIKI satellite, which is on the quasi-zenith orbit. As a first step, relationship among the space environment data and surface charging data obtained from MICHIBIKI satellite, and space environment data obtained from global magnetospheric MHD simulation are examined. Since the MHD simulation calculate temperature and density as single MHD fluid, an empirical relationship between simulation and observation needs to be made for obtaining the estimated temperature and density of electrons and ions. Initial comparison is introduced in this paper.

Comparative analysis of GF-1, HJ-1, and Landsat-8 data for estimating the leaf area index of winter wheat

Using simultaneously collected remote sensing data and field measurements, this study firstly assessed the consistency and applicability of China high-resolution earth observation system satellite 1 (GF-1) wide field of view (WFV) camera, environment and disaster monitoring and forecasting satellite (HJ-1) charge coupled device (CCD), and Landsat-8 operational land imager (OLI) data for estimating the leaf area index (LAI) of winter wheat via reflectance and vegetation indices (VIs). The accuracies of these LAI estimates were then assessed through comparison with an empirical model and the PROSAIL radiative transfer model. The effects of radiation calibration, spectral response functions, and spatial resolution on discrepancies in the LAI estimates between the different sensors were also analyzed. The results yielded the following observations: (1) The correlation between reflectance from different sensors is relative good, with the adjusted coefficients of determination (R2) between 0.375 to 0.818. The differences in reflectance are ranging from 0.002 to 0.054. The correlation between VIs from different sensors is high with the R2 between 0.729 and 0.933. The differences in the VIs are ranging from 0.07 to 0.156. These results show the three sensors' images can all be used for cross calibration of the reflectance and VIs. (2) The four VIs from the three sensors are all demonstrated to be highly correlated with LAI (R2 between 0.703 and 0.849). The linear models associated with the 2-band enhanced vegetation index (EVI2), which feature the highest R2 (higher than 0.746) and the lowest root mean square errors (RMSE) (less than 0.21), were selected to estimate the winter wheat LAI. The accuracy of the estimated LAI from Landsat-8 was the highest, with the relative errors (RE) of 2.18% and an RMSE of 0.13, while the HJ-1 was the lowest, with the RE of 2.43% and the RMSE of 0.15. (3) The inversion errors in the different sensors' LAI estimates using the PROSAIL model are small. The accuracy of the GF-1 is the highest with the RE of 3.44%, and the RMSE of 0.22, whereas that of the HJ-1 is the lowest with the RE of 4.95%, and the RMSE of 0.26. (4) The effects of the spectral response function and radiation calibration for the different sensors are small and can be ignored, but the effects of spatial resolution are significant and must be taken into consideration in practical applications.

Predicting Grassland Leaf Area Index in the Meadow Steppes of Northern China: A Comparative Study of Regression Approaches and Hybrid Geostatistical Methods

Leaf area index (LAI) is a key parameter used to describe vegetation structures and is widely used in ecosystem biophysical process and vegetation productivity models. Many algorithms have been developed for the estimation of LAI based on remote sensing images. Our goal was to produce accurate and timely predictions of grassland LAI for the meadow steppes of northern China. Here, we compare the predictive power of regression approaches and hybrid geostatistical methods using Chinese Huanjing (HJ) satellite charge coupled device (CCD) data. The regression methods evaluated include partial least squares regression (PLSR), artificial neural networks (ANNs) and random forests (RFs). The two hybrid geostatistical methods were regression kriging (RK) and random forests residuals kriging (RFRK). The predictions were validated for different grassland types and different growing stages, and their performances were also examined by adding several groups of vegetation indices (VIs). The two hybrid geostatistical models (RK and RFRK) yielded the most accurate predictions (root mean squared error (RMSE) = 0.21 m2/m2 and 0.23 m2/m2 for RK and RFRK, respectively), followed by the RF model (RMSE = 0.27 m2/m2), which was the most accurate among the regression models. These three models also exhibited the best temporal performance across the duration of the growing season. The PLSR and ANN models were less accurate (RMSE = 0.33 m2/m2 and 0.35 m2/m2 for ANN and PLSR, respectively), and the PLSR model performed the worst (exhibiting varied temporal performance and unreliable prediction accuracy that was susceptible to ground conditions). By adding VIs to the predictor variables, the predictions of the PLSR and ANN models were obviously improved (RMSE improved from 0.35 m2/m2 to 0.28 m2/m2 for PLSR and from 0.33 m2/m2 to 0.28 m2/m2 for ANN); the RF and RFRK models did not generate more accurate predictions and the performance of the RK model declined (RMSE decreased from 0.21 m2/m2 to 0.32 m2/m2).

Reconstruction of Daily 30 m Data from HJ CCD, GF-1 WFV, Landsat, and MODIS Data for Crop Monitoring

With the recent launch of new satellites and the developments of spatiotemporal data fusion methods, we are entering an era of high spatiotemporal resolution remote-sensing analysis. This study proposed a method to reconstruct daily 30 m remote-sensing data for monitoring crop types and phenology in two study areas located in Xinjiang Province, China. First, the Spatial and Temporal Data Fusion Approach (STDFA) was used to reconstruct the time series high spatiotemporal resolution data from the Huanjing satellite charge coupled device (HJ CCD), Gaofen satellite no. 1 wide field-of-view camera (GF-1 WFV), Landsat, and Moderate Resolution Imaging Spectroradiometer (MODIS) data. Then, the reconstructed time series were applied to extract crop phenology using a Hybrid Piecewise Logistic Model (HPLM). In addition, the onset date of greenness increase (OGI) and greenness decrease (OGD) were also calculated using the simulated phenology. Finally, crop types were mapped using the phenology information. The results show that the reconstructed high spatiotemporal data had a high quality with a proportion of good observations (PGQ) higher than 0.95 and the HPLM approach can simulate time series Normalized Different Vegetation Index (NDVI) very well with R2 ranging from 0.635 to 0.952 in Luntai and 0.719 to 0.991 in Bole, respectively. The reconstructed high spatiotemporal data were able to extract crop phenology in single crop fields, which provided a very detailed pattern relative to that from time series MODIS data. Moreover, the crop types can be classified using the reconstructed time series high spatiotemporal data with overall accuracy equal to 0.91 in Luntai and 0.95 in Bole, which is 0.028 and 0.046 higher than those obtained by using multi-temporal Landsat NDVI data.

Combining HJ CCD, GF-1 WFV and MODIS Data to Generate Daily High Spatial Resolution Synthetic Data for Environmental Process Monitoring.

The limitations of satellite data acquisition mean that there is a lack of satellite data with high spatial and temporal resolutions for environmental process monitoring. In this study, we address this problem by applying the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) and the Spatial and Temporal Data Fusion Approach (STDFA) to combine Huanjing satellite charge coupled device (HJ CCD), Gaofen satellite no. 1 wide field of view camera (GF-1 WFV) and Moderate Resolution Imaging Spectroradiometer (MODIS) data to generate daily high spatial resolution synthetic data for land surface process monitoring. Actual HJ CCD and GF-1 WFV data were used to evaluate the precision of the synthetic images using the correlation analysis method. Our method was tested and validated for two study areas in Xinjiang Province, China. The results show that both the ESTARFM and STDFA can be applied to combine HJ CCD and MODIS reflectance data, and GF-1 WFV and MODIS reflectance data, to generate synthetic HJ CCD data and synthetic GF-1 WFV data that closely match actual data with correlation coefficients (r) greater than 0.8989 and 0.8643, respectively. Synthetic red- and near infrared (NIR)-band data generated by ESTARFM are more suitable for the calculation of Normalized Different Vegetation Index (NDVI) than the data generated by STDFA.

Mapping Orchards on Plain Terrains Using Multi-Temporal Medium-Resolution Satellite Imagery

<abstract> <b><sc>Abstract. </sc></b>The ability to map the spatiotemporal distribution of orchards is essential in order to optimally utilize and manage their available resources. By analyzing multi-temporal characteristic and spectral features of medium-resolution images, the optimum features required to extract orchard data are determined and a classification rule set based on the object-based information analysis method (OBIA) is built. For those years in which images at key time points were missing, the extracted orchard data were used in the extraction process for these years as a thematic layer. The method was tested in Dangshan County, located in central China. Time series maps derived from the eight years of data over a nearly 20-year period from the Landsat Thematic Mapper (TM), Enhanced Thematic Mapper plus (ETM+) and China-HJ-1 satellite Charge Coupled Device agree well with field samples and historical records. Among the derived maps, the accuracy of orchard data derived from the 2010 HJ-1 images was estimated at about 92.9%. Compared with the common index, NDVI, the inclusion of IOPT (index for orchard in plain terrain) in the extraction process can lead to a significant improvement. When using a single-date image, the accuracies were all less than 70.0%, and when using multi-temporal images, an accuracy of 85.7% was achieved.

Compact Antenna for Small Satellite Applications [Antenna Applications Corner

The combined effort of the Universiti Kebangsaan Malaysia and the Kyushu Institute of Technology (KYUTECH) to develop a small-satellite antenna is presented in this paper. Microstrip antennas offer an ideal solution to satellite communication requirements due to their light weight and low profile. In this paper, a compact single-layer coaxial-probe-fed circularly polarized high-gain patch antenna designed for HORYU-IV nanosatellite S-band communication is presented. HORYU-IV aims to acquire data about high-voltage discharge phenomena in low Earth orbit (LEO). This will enhance the understanding of satellite charging, and overall satellite reliability can be improved for future high-power space programs. The proposed antenna consists of four asymmetric V-shaped slits, i.e., one at each corner of a rectangular patch, and a parasitic rectangular strip. The proposed antenna achieves a sufficient beamwidth for LEO satellite application and less than 3-dB axial ratio for the entire field of view. A prototype of the antenna was developed with a 1.57-mm-thick singlelayer Rogers substrate with a relative permittivity of 2.2, and the measured results are consistent with the simulation.

In-Orbit Demonstration of Newly Developed Passive Electron-Emitting Film for Spacecraft-Charging Mitigation

Recently, a passive electron-emitting film has been developed for the purpose of neutralization of all types of spacecraft charging. Applications are inclusive of satellites with high bus voltage in geostationary Earth orbit. This passive-type component emits electrons continuously from its triple junction under an inverted potential gradient condition after being exposed to a geostationary Earth orbit substorm. In this paper, the verification test has been conducted after designing circuitry that measures the surface potential as well as the emission of the film. In the ground test, the emitter was biased to a high negative potential with respect to the vacuum chamber to simulate the spacecraft potential achieved while floating in space plasma. The substorm condition and the satellite charging are simulated by irradiating the emitter with an electron beam. Under these conditions, the performance of the emitter has been confirmed via the developed circuitry. These results allow the flight demonstration of the electron emitter and circuitry as a mission payload on Horyu-2, the first satellite developed and deployed by the Kyushu Institute of Technology.

Modeling of current characteristics of segmented Langmuir probe on DEMETER

We model the current characteristics of the DEMETER Segmented Langmuir probe (SLP). The probe is used to measure electron density and temperature in the ionosphere at an altitude of approximately 700 km. It is also used to measure the plasma flow velocity in the satellite frame of reference. The probe is partitioned into seven collectors: six electrically insulated spherical segments and a guard electrode (the rest of the sphere and the small post). Comparisons are made between the predictions of the model and DEMETER measurements for actual ionospheric plasma conditions encountered along the satellite orbit. Segment characteristics are computed numerically with PTetra, a three-dimensional particle in cell simulation code. In PTetra, space is discretized with an unstructured tetrahedral mesh, thus, enabling a good representation of the probe geometry. The model also accounts for several physical effects of importance in the interaction of spacecraft with the space environment. These include satellite charging, photoelectron, and secondary electron emissions. The model is electrostatic, but it accounts for the presence of a uniform background magnetic field. PTetra simulation results show different characteristics for the different probe segments. The current collected by each segment depends on its orientation with respect to the ram direction, the plasma composition, the magnitude, and the orientation of the magnetic field. It is observed that the presence of light H+ ions leads to a significant increase in the ion current branch of the I-V curves of the negatively polarized SLP. The effect of the magnetic field is demonstrated by varying its magnitude and direction with respect to the reference magnetic field. It is found that the magnetic field appreciably affects the electron current branch of the I-V curves of certain segments on the SLP, whereas the ion current branch remains almost unaffected. PTetra simulations are validated by comparing the computed characteristics and their angular anisotropy with the DEMETER measurements, as simulation results are found to be in good agreement with the measurements.

Spectroscopic Measurement of Secondary Arc Plasma on Solar Array

As the power level of Geostationary satellites increases, discharge phenomena on solar array are becoming serious threat to safe operation. Arcs on solar array can short-circuit the satellite circuit, decrease the satellite power, and then cause the satellite permanent failure. To prevent the failure caused by charging and arcing, it is necessary to investigate the mechanism of satellite charging and arcing phenomenon. The purpose of this paper is to investigate the occurrence condition of a secondary arc by measuring arc plasma characteristics in ground test. We measured the arc plasma temperature and identified the materials emitted using spectrometer at arbitrary time during arc occurring. We investigated the difference of secondary arcs occurrence condition during secondary arcs. From the spectroscopic measurement results, we found that it was necessary for shifting to the secondary arc that the metallic vapor same as the cathode material was emitted. In case of primary arc (PA) dimension changes, the probability of secondary arc and TSA occurrence became high. And plasma temperature was not affected by PA dimension, however the metallic vapor emission of silver was greatly affected. Thus, secondary arc occurrence greatly depends on metallic vapor emission from cathode.

HEO Satellite Frame and Differential Charging and SCATHA Low-Level Frame Charging

Significant amounts of satellite charging data have been taken at geosynchronous (GEO) and near-GEO orbit and in low-altitude orbits. There are only limited satellite charging measurements at intermediate altitudes or at middle to high latitudes at high altitudes. In this paper, results of spacecraft frame and differential potentials are shown that were measured over several years on a highly elliptical orbit (HEO2) satellite with an apogee of ~7.2 R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> geocentric and ~63deg inclination. The HEO2 frame and differential charging data were obtained using a plasma spectrometer. Measurements of HEO2 charging levels les -30 V are summarized according to their occurrence in magnetic local time and L. The data show that the HEO2 satellite frame charged to potentials les -30 V, and that the occurrence of satellite frame charging at these high latitudes mimics the charging local time patterns observed by GEO satellites. In addition, the data show that such charging extends from at least a minimum L of les 4 R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> to L > 10 R <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> . It was found that the differential charging potential usually exceeded the frame potential and could be estimated by V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</sub> ~ 74 + 1.384 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">F</sub> . Separately, we show the results of a one-year study of the Spacecraft Charging AT High Altitude (SCATHA) satellite frame potential in the near-GEO region. SCATHA's frame potential was positive les 15% of the time and was ges - 1 V ~ 95% of the time. Large negative frame potentials (< - 1 V) occurred ~ 5% of the time. The data also showed that the large negative frame potentials preferentially occurred on the nightside, as expected, and that they occurred less that 1% of the time on the dayside. These statistics may be used as a reference for estimating the relative attraction of ionized outgassed contaminants for a satellite.

International Standards Will Enhance Space Weather Management

In the decade since the National Space Weather Program (NSWP) Implementation Plan (see http://www.nswp.gov/images/nswpip2000.pdf) was drafted and then published (2000), and the NSWP Assessment Committee produced its 2006 follow-on report (http://www.nswp.gov/nswp_acreport0706.pdf), an updated vision has been needed to guide our nation's space environment activities as the decade near solar maximum begins. This vision must include two parts: placing space weather management at the forefront of activities to go beyond the ongoing specification and prediction efforts, and working to create international space environment standards so that space activities are conducted with safety, efficiency, and the maximization of space commercialization.