Acta Astronautica最新文献

Preliminary analysis and design of an optical space surveillance and tracking constellation for LEO coverage

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-21 DOI: 10.1016/j.actaastro.2025.02.019

A. D’Anniballe, L. Felicetti, S. Hobbs

Accurately tracking space debris and operational satellites is the foundation of the long-term sustainability of space operations. To improve upon some of the inherent limitations of ground radars, a constellation of satellites carrying optical sensors for the surveillance of the Low Earth Orbit (LEO) region is analysed. This analysis aims to understand the performance drivers of such a system in terms of constellation geometry and provide a general methodology for the preliminary design of the system. First, a method for decoupling the design of the optical payload and the constellation geometry while retaining statistically significant results is shown. Using the resulting estimate for the maximum observable distance, an approximate method for computing the coverage of the system is proposed. The expected daily and yearly variation of coverage depending on its own dynamics and the position of the Sun is analysed, showing that it has a small impact on the design process. The dependence of the coverage on constellation parameters such as altitude, inclination and distribution of satellites is investigated through parametric analysis, retrieving an estimate for the Pareto front of the system. Building upon the previous results, a random search method is shown to be effective in finding a design point lying on the Pareto front that is robust to both random satellite loss and deployment strategy. Finally, a reduced budget architecture is proposed to achieve acceptable performance while using only a few tens of satellites. The resulting work answers the problems of estimating and optimising the performance of a distributed system for space-based surveillance of the LEO region, a stepping stone for future cost–benefit analyses for the enhancement of space surveillance networks.

{"title":"Preliminary analysis and design of an optical space surveillance and tracking constellation for LEO coverage","authors":"A. D’Anniballe, L. Felicetti, S. Hobbs","doi":"10.1016/j.actaastro.2025.02.019","DOIUrl":"10.1016/j.actaastro.2025.02.019","url":null,"abstract":"<div><div>Accurately tracking space debris and operational satellites is the foundation of the long-term sustainability of space operations. To improve upon some of the inherent limitations of ground radars, a constellation of satellites carrying optical sensors for the surveillance of the Low Earth Orbit (LEO) region is analysed. This analysis aims to understand the performance drivers of such a system in terms of constellation geometry and provide a general methodology for the preliminary design of the system. First, a method for decoupling the design of the optical payload and the constellation geometry while retaining statistically significant results is shown. Using the resulting estimate for the maximum observable distance, an approximate method for computing the coverage of the system is proposed. The expected daily and yearly variation of coverage depending on its own dynamics and the position of the Sun is analysed, showing that it has a small impact on the design process. The dependence of the coverage on constellation parameters such as altitude, inclination and distribution of satellites is investigated through parametric analysis, retrieving an estimate for the Pareto front of the system. Building upon the previous results, a random search method is shown to be effective in finding a design point lying on the Pareto front that is robust to both random satellite loss and deployment strategy. Finally, a reduced budget architecture is proposed to achieve acceptable performance while using only a few tens of satellites. The resulting work answers the problems of estimating and optimising the performance of a distributed system for space-based surveillance of the LEO region, a stepping stone for future cost–benefit analyses for the enhancement of space surveillance networks.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 47-63"},"PeriodicalIF":3.1,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation on acceleration process of field reversed configuration plasmoid in an electrodeless Lorentz force thruster using Magnetohydrodynamics simulation

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-19 DOI: 10.1016/j.actaastro.2025.02.029

Zhehong Wang , Weizong Wang , Jiaqi Yan , Zihan Wang

Rotating Magnetic Field (RMF) driven Field Reversed Configuration (FRC) plasmoid, originating from magnetic confined fusion research, has been developed as a novel propulsion method for high-power electric thrusters, namely the electrodeless Lorentz force (ELF) thruster. To address the dilemma between the high potential in theory and the low performance in the experiment, this paper numerically investigates the acceleration processes of FRC plasmoid in ELF thruster through a two-dimensional Hall Magnetohydrodynamics method. Direct comparisons with experiments have been made to verify the model. The correlation between the plasma behavior and the thruster performance has been obtained, providing insight into the experimental phenomena. The power scaling rule of thruster performance is obtained by investigating the influence of magnetic field strength and thruster geometry on the exhaust velocity and momentum of the FRC plasmoid. The simulation revealed that the low thruster performance in recent experiments is due to the low power input. High performance is expected to be achievable by scaling up the input power to hundreds kW or MW levels. Increasing the bias field to more than 1000 G, RMF frequency to 1 MHz, and RMF strength to hundreds Gausses, enables a per-shot momentum of mNs level of and specific impulse to be more than 5000 s. Additionally, the contribution of gas pressure force and Lorentz body force to the plasmoid acceleration has been analyzed, showing that the magnetic forces are dominant in high power regime, whereas gas forces being dominant in low power regime. The power scaling rule and geometry design principle formed in this work can help improve the ELF thruster performance, highlighting the necessity of testing prototypes under high-power conditions.

{"title":"Investigation on acceleration process of field reversed configuration plasmoid in an electrodeless Lorentz force thruster using Magnetohydrodynamics simulation","authors":"Zhehong Wang , Weizong Wang , Jiaqi Yan , Zihan Wang","doi":"10.1016/j.actaastro.2025.02.029","DOIUrl":"10.1016/j.actaastro.2025.02.029","url":null,"abstract":"<div><div>Rotating Magnetic Field (RMF) driven Field Reversed Configuration (FRC) plasmoid, originating from magnetic confined fusion research, has been developed as a novel propulsion method for high-power electric thrusters, namely the electrodeless Lorentz force (ELF) thruster. To address the dilemma between the high potential in theory and the low performance in the experiment, this paper numerically investigates the acceleration processes of FRC plasmoid in ELF thruster through a two-dimensional Hall Magnetohydrodynamics method. Direct comparisons with experiments have been made to verify the model. The correlation between the plasma behavior and the thruster performance has been obtained, providing insight into the experimental phenomena. The power scaling rule of thruster performance is obtained by investigating the influence of magnetic field strength and thruster geometry on the exhaust velocity and momentum of the FRC plasmoid. The simulation revealed that the low thruster performance in recent experiments is due to the low power input. High performance is expected to be achievable by scaling up the input power to hundreds kW or MW levels. Increasing the bias field to more than 1000 G, RMF frequency to 1 MHz, and RMF strength to hundreds Gausses, enables a per-shot momentum of mNs level of and specific impulse to be more than 5000 s. Additionally, the contribution of gas pressure force and Lorentz body force to the plasmoid acceleration has been analyzed, showing that the magnetic forces are dominant in high power regime, whereas gas forces being dominant in low power regime. The power scaling rule and geometry design principle formed in this work can help improve the ELF thruster performance, highlighting the necessity of testing prototypes under high-power conditions.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 1-14"},"PeriodicalIF":3.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Insertion error correction and configuration maintenance optimization for geocentric gravitational wave detectors

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-19 DOI: 10.1016/j.actaastro.2025.02.016

Xuan Xie, Fanghua Jiang, Junfeng Li

Space-based gravitational wave detectors have attracted considerable attention for their ability to detect low frequency gravitational waves generated by the universe’s most various sources. However, the high-precision detection requires extremely strict orbital insertion to maintain the configuration throughout the mission period. This paper presents an optimization method to correct orbital insertion errors using a low-frequency control strategy for long-duration, large-baseline spacecraft constellations. With active control, space-based gravitational wave detectors can mitigate initial orbit uncertainties. By presenting an evaluation algorithm and an estimating equation for fuel consumption and geometric indices, the segmented optimization method offers high computational efficiency. To adapt the control strategy to high-fidelity dynamics, an initial solution selection skill is proposed, and local refinements are employed. The application to the TianQin mission demonstrates the efficiency of the proposed method. The active control not only corrects the orbital insertion error but also reduces the geometric changes of the configuration by nearly 30% compared to an ideal deployment. The configuration maintenance strategy balances fuel efficiency and geometric stability, with a fuel consumption of only 421.57 m/s over the five-year mission period.

{"title":"Insertion error correction and configuration maintenance optimization for geocentric gravitational wave detectors","authors":"Xuan Xie, Fanghua Jiang, Junfeng Li","doi":"10.1016/j.actaastro.2025.02.016","DOIUrl":"10.1016/j.actaastro.2025.02.016","url":null,"abstract":"<div><div>Space-based gravitational wave detectors have attracted considerable attention for their ability to detect low frequency gravitational waves generated by the universe’s most various sources. However, the high-precision detection requires extremely strict orbital insertion to maintain the configuration throughout the mission period. This paper presents an optimization method to correct orbital insertion errors using a low-frequency control strategy for long-duration, large-baseline spacecraft constellations. With active control, space-based gravitational wave detectors can mitigate initial orbit uncertainties. By presenting an evaluation algorithm and an estimating equation for fuel consumption and geometric indices, the segmented optimization method offers high computational efficiency. To adapt the control strategy to high-fidelity dynamics, an initial solution selection skill is proposed, and local refinements are employed. The application to the TianQin mission demonstrates the efficiency of the proposed method. The active control not only corrects the orbital insertion error but also reduces the geometric changes of the configuration by nearly 30% compared to an ideal deployment. The configuration maintenance strategy balances fuel efficiency and geometric stability, with a fuel consumption of only 421.57 m/s over the five-year mission period.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 15-24"},"PeriodicalIF":3.1,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical simulation of droplets collision with account of surface tension at axisymmetric statement

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-17 DOI: 10.1016/j.actaastro.2025.02.026

V.V. Tyurenkova , P.P. Zakharov , N.N. Smirnov

To model and develop rocket, gas turbine and diesel, engines, as well as other devices operating on liquid fuel (for example, boilers and furnaces), the mechanism of interaction of individual droplets, which is a fundamental aspect for understanding processes occurring in heterogeneous systems, should be studied. In addition, the interaction of droplets plays an important role in modeling engines, the work of which is based on detonation combustion of fuel, since the presence of individual droplets in the stream is one of the key factors affecting the spread and formation of a sustainable detonation wave.

The paper presents the model for simulation multimaterial compressible flows with surface tension. Numerical method of sharp interface type is supplemented with surface tension model in terms of continuum surface stress model. Each integration step is divided into stages, pure hydrodynamic stage and surface tension stage. Smoothing procedure for volume fractions is additionally introduced to evaluate surface tension stress tensor. Suggested method is verified by problems with analytical solutions: static droplet, oscillating droplet and Rayleigh–Taylor instability development. Using the verified numerical method, the problem of ethanol droplet collision with different velocities was simulated. The numerical method described in this paper was verified by comparison with analytical solutions and validated on the basis of experimental data.

{"title":"Numerical simulation of droplets collision with account of surface tension at axisymmetric statement","authors":"V.V. Tyurenkova , P.P. Zakharov , N.N. Smirnov","doi":"10.1016/j.actaastro.2025.02.026","DOIUrl":"10.1016/j.actaastro.2025.02.026","url":null,"abstract":"<div><div>To model and develop rocket, gas turbine and diesel, engines, as well as other devices operating on liquid fuel (for example, boilers and furnaces), the mechanism of interaction of individual droplets, which is a fundamental aspect for understanding processes occurring in heterogeneous systems, should be studied. In addition, the interaction of droplets plays an important role in modeling engines, the work of which is based on detonation combustion of fuel, since the presence of individual droplets in the stream is one of the key factors affecting the spread and formation of a sustainable detonation wave.</div><div>The paper presents the model for simulation multimaterial compressible flows with surface tension. Numerical method of sharp interface type is supplemented with surface tension model in terms of continuum surface stress model. Each integration step is divided into stages, pure hydrodynamic stage and surface tension stage. Smoothing procedure for volume fractions is additionally introduced to evaluate surface tension stress tensor. Suggested method is verified by problems with analytical solutions: static droplet, oscillating droplet and Rayleigh–Taylor instability development. Using the verified numerical method, the problem of ethanol droplet collision with different velocities was simulated. The numerical method described in this paper was verified by comparison with analytical solutions and validated on the basis of experimental data.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 79-91"},"PeriodicalIF":3.1,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mission analysis for the Radiation Environment Monitor for Energetic Cosmic rays (REMEC) mission

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-15 DOI: 10.1016/j.actaastro.2025.02.013

Mathilda Bolis , Elisa Maria Alessi , Camilla Colombo

The Radiation Environment Monitor for Energetic Cosmic rays (REMEC) is a micro-sat mission developed to reach deep space to study, for the first time outside the Earth’s magnetosphere, Solar Energetic Particles (SEP). The main scientific payloads consist of the Penetrating particle ANalyzer magnetic spectrometer (Pix.PAN), based on Timepix4 technology, and the HardPix radiation monitors. The trajectory design developed for the REMEC mission phases 0-A and B1 is described herein. First, possible operational orbits in the Sun–Earth (SE) and Earth–Moon (EM) systems are identified. Then, by exploiting the Circular Restricted Three Body Problem (CR3BP), feasible trajectories are calculated for both a baseline and a backup option. The dynamical model for the baseline case is then refined, including the direct effect of the Moon on the dynamic. In addition, propulsion system requirements were to be considered in the analysis, and an orbit-raising strategy was developed. Finally, the results obtained with the refined dynamic, both on the operational orbit and the transfer trajectory, and with the orbit-raising strategy are shown and commented.

{"title":"Mission analysis for the Radiation Environment Monitor for Energetic Cosmic rays (REMEC) mission","authors":"Mathilda Bolis , Elisa Maria Alessi , Camilla Colombo","doi":"10.1016/j.actaastro.2025.02.013","DOIUrl":"10.1016/j.actaastro.2025.02.013","url":null,"abstract":"<div><div>The Radiation Environment Monitor for Energetic Cosmic rays (REMEC) is a micro-sat mission developed to reach deep space to study, for the first time outside the Earth’s magnetosphere, Solar Energetic Particles (SEP). The main scientific payloads consist of the Penetrating particle ANalyzer magnetic spectrometer (Pix.PAN), based on Timepix4 technology, and the HardPix radiation monitors. The trajectory design developed for the REMEC mission phases 0-A and B1 is described herein. First, possible operational orbits in the Sun–Earth (SE) and Earth–Moon (EM) systems are identified. Then, by exploiting the Circular Restricted Three Body Problem (CR3BP), feasible trajectories are calculated for both a baseline and a backup option. The dynamical model for the baseline case is then refined, including the direct effect of the Moon on the dynamic. In addition, propulsion system requirements were to be considered in the analysis, and an orbit-raising strategy was developed. Finally, the results obtained with the refined dynamic, both on the operational orbit and the transfer trajectory, and with the orbit-raising strategy are shown and commented.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 65-78"},"PeriodicalIF":3.1,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The basic data processing for KPLO gamma-ray spectrometer (KGRS)

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-15 DOI: 10.1016/j.actaastro.2025.02.018

Suyeon Kim, Kyeong Ja Kim, Ik-Seon Hong

On August 5, 2022, South Korea's first lunar probe, the Korea Pathfinder Lunar Orbiter (KPLO, DANURI) was launched and entered lunar orbit in December of the same year. The KPLO is currently conducting a mission with the KPLO Gamma-Ray Spectrometer (KGRS) developed by the Korea Institute of Geoscience and Mineral Resources (KIGAM). The primary objective of the KGRS is to collect gamma-ray spectral information on the lunar surface and create an elemental map. This paper discusses the basic processing steps of the KGRS data currently operating in lunar orbit and the data processing results for approximately one year. KGRS data is currently maintained in two categories: TM2 data, and TM3 data. We are also preparing the calibration (CAL) data. In the TM2 data stage, time conversion and correction are performed. In the TM3 data stage, the SPICE (Spacecraft Planet Instrument C-matrix Events) system is used to obtain satellite positional information. All KGRS data being transmitted to the KIGAM is monitored daily. The monitoring program displays and monitors the engineering data such as device temperature and science data such as gamma-ray counts. Monitoring gamma-ray counts allows us to detect events such as solar flares or gamma-ray bursts that could affect the data. Since that kind of data can not represent information on the lunar surface, the data at that time should be excluded from mapping data. To verify the result of the data selection, we compare the gamma-ray count maps before and after the exclusion of these data.

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引用次数: 0

Investigation on the mechanism of simulated microgravity promoting rat cerebral angiogenesis based on proteomics

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-14 DOI: 10.1016/j.actaastro.2025.02.024

Yaoyuan Cui , Huayan Liu , Zhuohan Li , Bin Luo , Juan Zhao , Shiyi Tang , Anqing Wang , Guan Wang , Jichen Du , Jing Yang

Changed neurovascular homeostasis under microgravity may be closely related to the dysregulated angiogenesis resulting in neurovascular units and microvascular hyperpermeability. The present study aimed to investigate the mechanism of 7-day simulated microgravity (7d-SMG) promoting rat cerebral angiogenesis based on proteomics. 7d-SMG effect led to a slight inflammatory infiltration in rat cerebral cortex. The levels of oxidative stress, inflammatory factors, and pro-angiogenic factors were significantly increased. A total of 5499 proteins were detected by label-free quantitative proteomic strategy and 704 proteins were differentially expressed proteins (DEPs). 440 and 264 of DEPs were upregulated and downregulated, respectively. Gene-Ontology analysis suggested that most of DEPs were involved in brain development, actin cytoskeleton and filament organization, cell proliferation, which were closely associated with cerebral angiogenesis. The KEGG results showed that Rap1, Ras and other signaling pathways related to cell proliferation were significantly influenced by 7d-SMG. The expressions of VEGFR2, Crk, Rap1b, B-Raf, and the radio of pho-MEK/MEK, pho-ERK1/2/ERK1/2, Bcl2/Bax were respectively increased by 47.24 %, 25.11 %, 22.02 %, 41.44 %, 22.34 %, 24.87 %, 120.65 %, which indicated that 7d-SMG promoted cell proliferation through VEGFR2-Rap1b-ERK signaling pathway. The present study explored the effect of 7d-SMG regulating rat cerebral angiogenesis, which provided a novel insight to elucidate the potential mechanism of disrupted neurovascular homeostasis induced by MG. The expected results might benefit for maintaining nerve system health of astronauts during space flight.

{"title":"Investigation on the mechanism of simulated microgravity promoting rat cerebral angiogenesis based on proteomics","authors":"Yaoyuan Cui , Huayan Liu , Zhuohan Li , Bin Luo , Juan Zhao , Shiyi Tang , Anqing Wang , Guan Wang , Jichen Du , Jing Yang","doi":"10.1016/j.actaastro.2025.02.024","DOIUrl":"10.1016/j.actaastro.2025.02.024","url":null,"abstract":"<div><div>Changed neurovascular homeostasis under microgravity may be closely related to the dysregulated angiogenesis resulting in neurovascular units and microvascular hyperpermeability. The present study aimed to investigate the mechanism of 7-day simulated microgravity (7d-SMG) promoting rat cerebral angiogenesis based on proteomics. 7d-SMG effect led to a slight inflammatory infiltration in rat cerebral cortex. The levels of oxidative stress, inflammatory factors, and pro-angiogenic factors were significantly increased. A total of 5499 proteins were detected by label-free quantitative proteomic strategy and 704 proteins were differentially expressed proteins (DEPs). 440 and 264 of DEPs were upregulated and downregulated, respectively. Gene-Ontology analysis suggested that most of DEPs were involved in brain development, actin cytoskeleton and filament organization, cell proliferation, which were closely associated with cerebral angiogenesis. The KEGG results showed that Rap1, Ras and other signaling pathways related to cell proliferation were significantly influenced by 7d-SMG. The expressions of VEGFR2, Crk, Rap1b, B-Raf, and the radio of pho-MEK/MEK, pho-ERK1/2/ERK1/2, Bcl2/Bax were respectively increased by 47.24 %, 25.11 %, 22.02 %, 41.44 %, 22.34 %, 24.87 %, 120.65 %, which indicated that 7d-SMG promoted cell proliferation through VEGFR2-Rap1b-ERK signaling pathway. The present study explored the effect of 7d-SMG regulating rat cerebral angiogenesis, which provided a novel insight to elucidate the potential mechanism of disrupted neurovascular homeostasis induced by MG. The expected results might benefit for maintaining nerve system health of astronauts during space flight.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"231 ","pages":"Pages 37-46"},"PeriodicalIF":3.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

New public-private partnership based on the interactive collaboration in the space sector

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-13 DOI: 10.1016/j.actaastro.2025.02.009

Shinichi Takata , Kazuyoshi Hidaka

This paper presents a new open innovation type of public-private partnership (PPP) to create a space industry, in which innovative technology development by the public R&D sector and space business creation by the private sector are simultaneously realized through bi-directional collaboration between the public and private sectors. This PPP type is a solution to the issues pointed out in previous studies, namely, the relative reduction of R&D opportunities for the public sector due to technological assistance to the private sector, and the decline in technological performance due to risk aversion in the private sector. Next, we present an evaluation method for this collaborative partnership based on the evaluation indicators for value co-creation research. Finally, to identify the process factors driving the projects in this PPP type, we surveyed about 30 space PPP projects in the Japanese space sector implemented since 2018. Then, the results of the qualitative comparative analysis (QCA) revealed that the factors are the estimation of mutual capabilities and benefits, the establishment of collaboration goals, and the commitment to mutual activities. The findings suggest that it is possible to define a new space PPP type that complements the space PPP typology of previous studies, and that it is possible to promote this space PPP project through appropriate management of two-way collaboration.

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引用次数: 0

Study on the impact of the potential variation in the CSES satellite platform on Langmuir probe observations

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-13 DOI: 10.1016/j.actaastro.2025.02.020

Weixing Pu , Rui Yan , Yibing Guan , Chao Xiong , Keying Zhu , Zhima Zeren , Dapeng Liu , Chao Liu , Yuanqing Miao , Zihang Wang

The Langmuir Probe (LAP) onboard China Seismo-Electromagnetic Satellite (CSES-01) operates by applying a sweeping bias-voltage (V) to its probe and measuring the resulting current (I). Plasma parameters are subsequently derived from the analysis of the current-voltage (I-V) characteristic curves. The sweeping bias-voltage (V) is referenced to the satellite platform's ground potential (Vg). A negative shift in Vg beyond the range of the sweeping bias-voltage can lead to incomplete I-V curves, thereby affecting the accuracy of LAP measurements. Over the past five years, the gradual drift in Vg on the CSES-01 satellite has caused observable disturbances in LAP data, particularly during ascending orbits around 02:00 local time. To mitigate the impact of Vg drift on LAP measurements, the range of the bias-voltage sweeping has been adjusted several times. This study analyzes five years of plasma density and temperature data from CSES-01's ascending orbits to investigate the influence of Vg variations on LAP observations and to evaluate the effectiveness of adjusting the bias-voltage sweeping range by comparing with the simultaneous Swarm-B measurements and IRI model predictions. The results demonstrate that, despite Vg drift, accurate observational data can still be obtained through the adjustments of the bias-voltage sweeping range. The latitudinal profiles, global distribution structures, and long-term temporal trends of electron density (Ne) and electron temperate (Te) accurately reflect the actual variations in the ionosphere. Notably, due to the bias-volatage adjustments, only a small fraction of the measurements is affected by Vg shifting. These findings provide valuable insights for effectively utilizing CSES-01 plasma data in scientific research. Furthermore, the identified issues and their solutions offer a critical reference for the design, development, and operation of similar Low-Earth-Orbit (LEO) satellites and Langmuir probes, ensuring their optimal performance and scientific reliability.

{"title":"Study on the impact of the potential variation in the CSES satellite platform on Langmuir probe observations","authors":"Weixing Pu , Rui Yan , Yibing Guan , Chao Xiong , Keying Zhu , Zhima Zeren , Dapeng Liu , Chao Liu , Yuanqing Miao , Zihang Wang","doi":"10.1016/j.actaastro.2025.02.020","DOIUrl":"10.1016/j.actaastro.2025.02.020","url":null,"abstract":"<div><div>The Langmuir Probe (LAP) onboard China Seismo-Electromagnetic Satellite (CSES-01) operates by applying a sweeping bias-voltage (<em>V</em>) to its probe and measuring the resulting current (<em>I</em>). Plasma parameters are subsequently derived from the analysis of the current-voltage (<em>I-V</em>) characteristic curves. The sweeping bias-voltage (<em>V</em>) is referenced to the satellite platform's ground potential (<em>Vg</em>). A negative shift in <em>Vg</em> beyond the range of the sweeping bias-voltage can lead to incomplete <em>I-V</em> curves, thereby affecting the accuracy of LAP measurements. Over the past five years, the gradual drift in <em>Vg</em> on the CSES-01 satellite has caused observable disturbances in LAP data, particularly during ascending orbits around 02:00 local time. To mitigate the impact of <em>Vg</em> drift on LAP measurements, the range of the bias-voltage sweeping has been adjusted several times. This study analyzes five years of plasma density and temperature data from CSES-01's ascending orbits to investigate the influence of <em>Vg</em> variations on LAP observations and to evaluate the effectiveness of adjusting the bias-voltage sweeping range by comparing with the simultaneous Swarm-B measurements and IRI model predictions. The results demonstrate that, despite <em>Vg</em> drift, accurate observational data can still be obtained through the adjustments of the bias-voltage sweeping range. The latitudinal profiles, global distribution structures, and long-term temporal trends of electron density (<em>Ne</em>) and electron temperate (<em>Te</em>) accurately reflect the actual variations in the ionosphere. Notably, due to the bias-volatage adjustments, only a small fraction of the measurements is affected by <em>Vg</em> shifting. These findings provide valuable insights for effectively utilizing CSES-01 plasma data in scientific research. Furthermore, the identified issues and their solutions offer a critical reference for the design, development, and operation of similar Low-Earth-Orbit (LEO) satellites and Langmuir probes, ensuring their optimal performance and scientific reliability.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 104-118"},"PeriodicalIF":3.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143446149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A predictive model for reaction wheel assembly microvibration

IF 3.1 2区物理与天体物理 Q1 ENGINEERING, AEROSPACE

Acta Astronautica

Pub Date : 2025-02-12 DOI: 10.1016/j.actaastro.2025.02.006

Mattia M. Longato, Vladimir Yotov, Guglielmo S. Aglietti

New generations of instruments contingent on high pointing accuracy are continuously pushing the requirements for satellite stability, but the microvibration disturbances originating from high-speed rotating devices such as reaction wheel assemblies (RWAs) remain an obstacle. In order to address this issue and improve current designs, accurate mathematical models of the noise sources are necessary. This paper presents a hybrid formulation which integrates a finite element-based representation of the rolling elements within an analytical model of a typical cantilevered reaction wheel, whose shaft is supported by two ball bearings. The model is able to predict both the frequency and amplitudes of the forces and moments produced at the RWA’s interface, allowing a comprehensive assessment of the emitted noise’s effect on the host satellite platform. At the bearing level, a wide range of structural parameters, such as preload, number and diameter of balls is handled in conjunction with various localised surface imperfections. It is shown that arbitrary combinations of bearing geometry and defect distributions can be efficiently synthesised from a limited set of responses precomputed by detailed nonlinear transient simulations. Using this capability, the article identifies bearing design trends exhibiting favourable performance in terms of overall emitted microvibration. Furthermore, spatial pairings of these bearing models are introduced in the governing equations of motion of an unbalanced rotor, enabling the evaluation of system-level responses. Finally, the proposed model is validated against test measurements of a physical rotor assembly, showing good agreement between predicted and measured microvibration signatures.

{"title":"A predictive model for reaction wheel assembly microvibration","authors":"Mattia M. Longato, Vladimir Yotov, Guglielmo S. Aglietti","doi":"10.1016/j.actaastro.2025.02.006","DOIUrl":"10.1016/j.actaastro.2025.02.006","url":null,"abstract":"<div><div>New generations of instruments contingent on high pointing accuracy are continuously pushing the requirements for satellite stability, but the microvibration disturbances originating from high-speed rotating devices such as reaction wheel assemblies (RWAs) remain an obstacle. In order to address this issue and improve current designs, accurate mathematical models of the noise sources are necessary. This paper presents a hybrid formulation which integrates a finite element-based representation of the rolling elements within an analytical model of a typical cantilevered reaction wheel, whose shaft is supported by two ball bearings. The model is able to predict both the frequency and amplitudes of the forces and moments produced at the RWA’s interface, allowing a comprehensive assessment of the emitted noise’s effect on the host satellite platform. At the bearing level, a wide range of structural parameters, such as preload, number and diameter of balls is handled in conjunction with various localised surface imperfections. It is shown that arbitrary combinations of bearing geometry and defect distributions can be efficiently synthesised from a limited set of responses precomputed by detailed nonlinear transient simulations. Using this capability, the article identifies bearing design trends exhibiting favourable performance in terms of overall emitted microvibration. Furthermore, spatial pairings of these bearing models are introduced in the governing equations of motion of an unbalanced rotor, enabling the evaluation of system-level responses. Finally, the proposed model is validated against test measurements of a physical rotor assembly, showing good agreement between predicted and measured microvibration signatures.</div></div>","PeriodicalId":44971,"journal":{"name":"Acta Astronautica","volume":"230 ","pages":"Pages 39-53"},"PeriodicalIF":3.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0