Pub Date : 2024-12-01DOI: 10.1016/j.jsse.2024.04.003
Tobias Rabus
An important part of a flight safety analysis for launch and re-entry events is to ensure safety to air and sea traffic, and maritime infrastructure. Thus, hazard areas are defined based on a risk assessment and risk criteria. Traffic impact depends on size and duration of those areas. Current risk criteria for air and sea traffic as well as maritime infrastructure are reviewed in this paper. Furthermore, this paper will take a closer look on other external risk factors in the aviation or maritime sector. The paper analyses their influence on aviation and maritime operations together with its associated safety measures and compares them with the risk posed by space vehicles. Understanding these relationships can support the conduct of safe space operations and efficient integration of space activities.
{"title":"Handling of external risks, including launch and re-entry events, in the aviation and maritime sector","authors":"Tobias Rabus","doi":"10.1016/j.jsse.2024.04.003","DOIUrl":"10.1016/j.jsse.2024.04.003","url":null,"abstract":"<div><div>An important part of a flight safety analysis for launch and re-entry events is to ensure safety to air and sea traffic, and maritime infrastructure. Thus, hazard areas are defined based on a risk assessment and risk criteria. Traffic impact depends on size and duration of those areas. Current risk criteria for air and sea traffic as well as maritime infrastructure are reviewed in this paper. Furthermore, this paper will take a closer look on other external risk factors in the aviation or maritime sector. The paper analyses their influence on aviation and maritime operations together with its associated safety measures and compares them with the risk posed by space vehicles. Understanding these relationships can support the conduct of safe space operations and efficient integration of space activities.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 4","pages":"Pages 673-680"},"PeriodicalIF":1.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141141975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rocket and space activities are developing worldwide, but environmental concerns are overlooked in pursuing new technologies. The Republic of Kazakhstan's "Baikonur" Cosmodrome routinely launches rockets in emergencies, causing toxic fuel to spill onto and contaminate the soil. This study examines the effect of T-1 kerosene, a hydrocarbon rocket fuel of toxic hazard class 4, on the soil microbial community from the aeration zone in laboratory conditions. In three different soil samples, 15 g/kg, 30 g/kg, and 50 g/kg of T-1 kerosene were tested according to their utilization by microbes throughout three, ten, and thirty days.
Based on scientific research, several strains of microorganisms were able to utilize T-1 kerosene rocket fuel, such as Acinetobacter calcoaceticum-18, Bacillus sp.-20, Micrococcus roseus-25, and Candida sp.-12/5, purifying it from 70 to 90 %. According to a study conducted after 30 days of microbiological detoxification of calcisols (loamic) (site 196) and dystric arenosols (site 31), with an initial load of 50 g/kg of T-1 kerosene, the concentration was determined. Microorganisms that produce 5 + 20 (99.83 %) and 18+20+25+12/5 (99.80 %) oil products are well utilized. During decontamination of soils contaminated with hydrocarbons was found to be present in the soil after 60 days when microorganism № 20 was used at 9.3 mg/kg, and the association of microorganism 5 + 25 at 8.88 mg/kg. The article describes the developed technology for soil detoxification using the microbiological method.
{"title":"Detoxification of contaminated soils from hydrocarbon rocket fuel used in «Soyuz» launch vehicles using the bioremediation method","authors":"Yerlan Bekeshev , Zhazira Zhumabekova , Meirbek Moldabekov","doi":"10.1016/j.jsse.2024.07.004","DOIUrl":"10.1016/j.jsse.2024.07.004","url":null,"abstract":"<div><div>Rocket and space activities are developing worldwide, but environmental concerns are overlooked in pursuing new technologies. The Republic of Kazakhstan's \"Baikonur\" Cosmodrome routinely launches rockets in emergencies, causing toxic fuel to spill onto and contaminate the soil. This study examines the effect of T-1 kerosene, a hydrocarbon rocket fuel of toxic hazard class 4, on the soil microbial community from the aeration zone in laboratory conditions. In three different soil samples, 15 g/kg, 30 g/kg, and 50 g/kg of T-1 kerosene were tested according to their utilization by microbes throughout three, ten, and thirty days.</div><div>Based on scientific research, several strains of microorganisms were able to utilize T-1 kerosene rocket fuel, such as <em>Acinetobacter calcoaceticum</em>-18, <em>Bacillus</em> sp.-20, <em>Micrococcus roseus-</em>25, and <em>Candida</em> sp.-12/5, purifying it from 70 to 90 %. According to a study conducted after 30 days of microbiological detoxification of calcisols (loamic) (site 196) and dystric arenosols (site 31), with an initial load of 50 g/kg of T-1 kerosene, the concentration was determined. Microorganisms that produce 5 + 20 (99.83 %) and 18+20+25+12/5 (99.80 %) oil products are well utilized. During decontamination of soils contaminated with hydrocarbons was found to be present in the soil after 60 days when microorganism № 20 was used at 9.3 mg/kg, and the association of microorganism 5 + 25 at 8.88 mg/kg. The article describes the developed technology for soil detoxification using the microbiological method.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 4","pages":"Pages 605-613"},"PeriodicalIF":1.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141851777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.jsse.2024.11.005
Andrew Berkowitz , Simon Titulaer
Intact impact yield curves are a key flight safety analysis input to assess the risk from explosive blast and Distant Focusing Overpressure (DFO) effects. Many new launch vehicles are utilizing Liquid Oxygen and Liquid Methane (LOX/Methane) as their propellants, a combination that does not have a historical yield curve. This paper describes SpaceX's work to develop a new LOX/Methane yield curve; unlike traditional yield curves, this work includes characterizing the effects of the launch vehicle's design and its breakup behavior. SpaceX expanded on the work of Blackwood et al. [1] to evaluate the theoretical explosive potential of an impacting launch vehicle. The theoretical model was then tested in a subscale test campaign like Project PYRO and HOVI, consisting of over 40 drop tests. The theoretical model, testing data, and launch vehicle design can be used to generate a conservative LOX/Methane yield curve for a new launch vehicle.
{"title":"Development of a Lox/Methane intact impact yield curve for a new launch vehicle","authors":"Andrew Berkowitz , Simon Titulaer","doi":"10.1016/j.jsse.2024.11.005","DOIUrl":"10.1016/j.jsse.2024.11.005","url":null,"abstract":"<div><div>Intact impact yield curves are a key flight safety analysis input to assess the risk from explosive blast and Distant Focusing Overpressure (DFO) effects. Many new launch vehicles are utilizing Liquid Oxygen and Liquid Methane (LOX/Methane) as their propellants, a combination that does not have a historical yield curve. This paper describes SpaceX's work to develop a new LOX/Methane yield curve; unlike traditional yield curves, this work includes characterizing the effects of the launch vehicle's design and its breakup behavior. SpaceX expanded on the work of Blackwood et al. [1] to evaluate the theoretical explosive potential of an impacting launch vehicle. The theoretical model was then tested in a subscale test campaign like Project PYRO and HOVI, consisting of over 40 drop tests. The theoretical model, testing data, and launch vehicle design can be used to generate a conservative LOX/Methane yield curve for a new launch vehicle.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 4","pages":"Pages 590-604"},"PeriodicalIF":1.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-01DOI: 10.1016/j.jsse.2024.09.003
Sayavur I. Bakhtiyarov , Elguja R. Kutelia , David Gventsadze , Ayten S. Bakhtiyarova , Stephen M. White
Polymers are of interest for use on spacecraft surfaces as dielectrics and electrical insulators, and polytetrafluoroethylene (PTFE) is a polymer with mechanical advantages, but low conductivity. Fe-doped carbon nanotubes (CNT) can be added to the polymer matrix and may improve their electrical properties. This work measures the volume and surface resistivity for PTFE and PTFE + Fe-doped CNT test specimens using the Keithley 6517B Electrometer/High Resistance Meter system, by determining current levels through the samples as a function of applied voltage. The system noise current was measured and averaged to be 4.83×10−15 Amps. The results obtained show that both volume and surface resistivities of pristine PTFE increase with increasing voltage. The volume resistivity is higher if compared to the surface resistivity at the same voltage. The conductivities of PTFE + Fe doped CNTs composites are higher as compared to the pristine PTFE, which can be contributed to the Fe-doped CNTs. The conductivity of the PTFE + Fe doped CNTs composite material increases with the concentration of the Fe-doped CNTs.
{"title":"An effect of Fe atom clusters doped CNTs on resistivity of PTFE dielectrics","authors":"Sayavur I. Bakhtiyarov , Elguja R. Kutelia , David Gventsadze , Ayten S. Bakhtiyarova , Stephen M. White","doi":"10.1016/j.jsse.2024.09.003","DOIUrl":"10.1016/j.jsse.2024.09.003","url":null,"abstract":"<div><div>Polymers are of interest for use on spacecraft surfaces as dielectrics and electrical insulators, and polytetrafluoroethylene (PTFE) is a polymer with mechanical advantages, but low conductivity. Fe-doped carbon nanotubes (CNT) can be added to the polymer matrix and may improve their electrical properties. This work measures the volume and surface resistivity for PTFE and PTFE + Fe-doped CNT test specimens using the Keithley 6517B Electrometer/High Resistance Meter system, by determining current levels through the samples as a function of applied voltage. The system noise current was measured and averaged to be 4.83×10<sup>−15</sup> Amps. The results obtained show that both volume and surface resistivities of pristine PTFE increase with increasing voltage. The volume resistivity is higher if compared to the surface resistivity at the same voltage. The conductivities of PTFE + Fe doped CNTs composites are higher as compared to the pristine PTFE, which can be contributed to the Fe-doped CNTs. The conductivity of the PTFE + Fe doped CNTs composite material increases with the concentration of the Fe-doped CNTs.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 4","pages":"Pages 614-621"},"PeriodicalIF":1.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 10.1016/j.jsse.2024.04.012
Matthew K. Brown, Sean Elvidge
Atmospheric drag is a major perturbation in Low Earth Orbit (LEO). The neutral density obtained from atmospheric models is a major source of uncertainty in drag calculations and therefore orbital propagation in LEO. Many atmospheric models are available, with fast empirical models most commonly used. We explore the challenges and benefits of using numerical models, specifically the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X) as part of the Community Earth System Model (CESM). Numerical models provide higher resolution of thermospheric structures, along with more accurate neutral density forecasts through assimilative models such as the Advanced Ensemble electron Density Assimilation System (AENeAS). Solutions are presented to overcome the challenges of using numerical models for neutral densities.
{"title":"Using WACCM-X neutral densities for orbital propagation: Challenges and solutions","authors":"Matthew K. Brown, Sean Elvidge","doi":"10.1016/j.jsse.2024.04.012","DOIUrl":"10.1016/j.jsse.2024.04.012","url":null,"abstract":"<div><div>Atmospheric drag is a major perturbation in Low Earth Orbit (LEO). The neutral density obtained from atmospheric models is a major source of uncertainty in drag calculations and therefore orbital propagation in LEO. Many atmospheric models are available, with fast empirical models most commonly used. We explore the challenges and benefits of using numerical models, specifically the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X) as part of the Community Earth System Model (CESM). Numerical models provide higher resolution of thermospheric structures, along with more accurate neutral density forecasts through assimilative models such as the Advanced Ensemble electron Density Assimilation System (AENeAS). Solutions are presented to overcome the challenges of using numerical models for neutral densities.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 411-416"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 10.1016/j.jsse.2024.06.003
NASA and ESA are currently planning the Mars Sample Return campaign, comprising missions whose combined objective is to bring the first samples of Mars material back to Earth for detailed study. Until recently, the NASA-ESA plan was to return samples to Earth using three missions. The final component, the Earth Entry System (EES), will bring the Mars samples back to the Earth, where it will land following safe entry through the Earth's atmosphere. There is a concern regarding the risk of biological contamination of the Earth's biosphere from returned Mars samples if, for example, the structural integrity of the EES were compromised during its return mission due to a perforation of a critical surface resulting from a high-speed meteoroid impact. To assess the risks associated with such an event, NASA is developing equations that predict the damage that various EES elements will sustain as a result of such an impact, as well as equations that predict whether or not a particular system will sustain a critical failure following such an impact. In this paper, we review recent progress in the development of such equations for the EES forebody and the EES aftbody, the two elements of the EES that are most exposed to the meteoroid environment. Limitations of the BLEs are also discussed, which can also be used to further inform the next steps in the BLE development.
美国航天局和欧空局目前正在规划火星取样返回活动，其中包括一些飞行任务，其共同目标是将第一批火星物质样品带回地球进行详细研究。直到最近，NASA-ESA 的计划是通过三次飞行任务将样本送回地球。最后一个部分，即地球进入系统（EES），将把火星样本带回地球，在安全进入地球大气层后在地球着陆。有人担心，如果在执行返回任务期间，由于高速流星体撞击导致关键表面穿孔，EES 的结构完整性受到破坏，返回的火星样本就有可能对地球生物圈造成生物污染。为了评估与此类事件相关的风险，NASA 正在开发一些方程，用于预测各种 EES 元件在此类撞击中将遭受的破坏，以及预测特定系统在此类撞击后是否会出现临界故障的方程。在本文中，我们回顾了最近在为 EES 前体和 EES 后体开发此类方程方面取得的进展，EES 前体和 EES 后体是 EES 中暴露在流星体环境中最多的两个元件。本文还讨论了 BLE 的局限性，这些局限性也可用于进一步指导 BLE 开发的下一步工作。
{"title":"Development of ballistic limit equations in support of the Mars sample return mission","authors":"","doi":"10.1016/j.jsse.2024.06.003","DOIUrl":"10.1016/j.jsse.2024.06.003","url":null,"abstract":"<div><div><span>NASA and ESA are currently planning the Mars Sample Return campaign, comprising missions whose combined objective is to bring the first samples of Mars material back to Earth for detailed study. Until recently, the NASA-ESA plan was to return samples to Earth using three missions. The final component, the Earth Entry System (EES), will bring the Mars samples back to the Earth, where it will land following safe entry through the Earth's atmosphere. There is a concern regarding the risk of biological contamination<span> of the Earth's biosphere from returned Mars samples if, for example, the structural integrity of the EES were compromised during its return mission due to a perforation of a critical surface resulting from a high-speed meteoroid impact. To assess the risks associated with such an event, NASA is developing equations that predict the damage that various EES elements will sustain as a result of such an impact, as well as equations that predict whether or not a particular system will sustain a critical failure following such an impact. In this paper, we review recent progress in the development of such equations for the EES </span></span>forebody and the EES aftbody, the two elements of the EES that are most exposed to the meteoroid environment. Limitations of the BLEs are also discussed, which can also be used to further inform the next steps in the BLE development.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 417-424"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141404831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Large-scale structures have a non-negligible collision probability with micrometeoroid and orbital debris (MMOD) due to their massive size, even in geostationary orbit (GEO) with low debris flux. When MMOD impact the spacecraft surfaces at high velocity, secondary debris called ejecta are generated, and they may remain semi-permanently and accumulate because there is no atmospheric drag at high altitudes such as GEO. To evaluate the amount of ejecta generation, hypervelocity impact tests were conducted for the material for future large-scale structures or material commonly used in conventional spacecraft, such as CFRP honeycomb panels and solar cells. The effect of impact energy on ejecta generation was evaluated by changing the impact velocity and projectile density. Impact tests were also conducted on irradiated samples to investigate the effects of environmental degradation due to long-term exposure to orbit. The results showed that the amount of ejecta increased with impact energy and may have been affected by radiation-induced degradation. Next, hypervelocity impact tests were conducted to investigate the measures to reduce ejecta, and it was shown that the ejecta generation could be reduced by using low-density materials such as polyimide foam and silica aerogel.
{"title":"Estimation of ejecta generation and mitigation measures for large-scale structures on geostationary orbit","authors":"Satomi Kawamoto , Ryusuke Harada , Daisuke Joudoi , Yugo Kimoto , Taku Izumiyama , Yasuhiro Akahoshi","doi":"10.1016/j.jsse.2024.06.005","DOIUrl":"10.1016/j.jsse.2024.06.005","url":null,"abstract":"<div><div>Large-scale structures have a non-negligible collision probability<span> with micrometeoroid<span><span><span><span> and orbital debris (MMOD) due to their massive size, even in geostationary orbit (GEO) with low debris flux. When MMOD impact the spacecraft surfaces at high velocity, secondary debris called </span>ejecta<span> are generated, and they may remain semi-permanently and accumulate because there is no atmospheric drag at high altitudes such as GEO. To evaluate the amount of ejecta generation, </span></span>hypervelocity impact tests were conducted for the material for future large-scale structures or material commonly used in conventional spacecraft, such as CFRP honeycomb panels and solar cells. The effect of impact energy on ejecta generation was evaluated by changing the </span>impact velocity<span><span> and projectile density. Impact tests were also conducted on irradiated samples to investigate the effects of environmental degradation due to long-term exposure to orbit. The results showed that the amount of ejecta increased with impact energy and may have been affected by radiation-induced degradation. Next, hypervelocity impact tests were conducted to investigate the measures to reduce ejecta, and it was shown that the ejecta generation could be reduced by using low-density materials such as </span>polyimide<span> foam and silica aerogel.</span></span></span></span></div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 507-517"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141704579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Every on-orbit collision or explosion can pose a threat, not only to the existing satellite population but also to the long-term usability of Earth orbit. This threat exists even if satellites can actively maneuver to avoid trackable debris fragments, since an estimated 96 % of potentially mission-ending (>1 cm) debris is untrackable [1]. Prevention of every on-orbit breakup may not be possible. However, armed with an understanding of the likely causes of fragmentation events, satellite developers and operators can take actions to mitigate such events in the future. Astrodynamics forensic analyses, the sleuthing techniques used to gather an event's known details and estimate its unknown parameters, can be used to develop theories about the causes of a breakup and to predict its consequences.
In the past five years, several on-orbit collisions and explosions have occurred, involving a variety of orbiting objects with varying amounts of available observational data. Techniques and tools developed over decades at The Aerospace Corporation are used to characterize key parameters of these events, including spread velocity of the debris pieces, energy involved in the breakup events, and mass and area estimates of the individual debris fragments. These forensic capabilities are enhanced by utilizing patterns identified from different classes of historical breakups and ground-test data. This paper shows the effectiveness of this methodology when used for analysis of a variety of event types including collisions, such as the Cosmos 1408 ASAT test and SL-14 rocket body breakup, rocket body fragmentations such as the 2022 Long March 6A breakup, and satellite fragmentations such as the Resur-O1 breakup. Representative models of events are developed using the IMPACT fragmentation tool, and predictions of the lifetimes of the subtrackable orbital debris are included. Where event sources are unknown, breakup parameters and trends are used to suggest possible causes. The challenges of analyzing an orbital breakup mystery with few observational clues are also discussed.
{"title":"Forensic analysis of recent debris-generating events","authors":"D.L. Mains , G.E. Peterson , J.P. McVey , J.C. Maldonado , M.E. Sorge","doi":"10.1016/j.jsse.2024.06.006","DOIUrl":"10.1016/j.jsse.2024.06.006","url":null,"abstract":"<div><div>Every on-orbit collision or explosion can pose a threat, not only to the existing satellite population but also to the long-term usability of Earth orbit. This threat exists even if satellites can actively maneuver to avoid trackable debris fragments, since an estimated 96 % of potentially mission-ending (>1 cm) debris is untrackable [<span><span>1</span></span><span>]. Prevention of every on-orbit breakup may not be possible. However, armed with an understanding of the likely causes of fragmentation events, satellite developers and operators can take actions to mitigate such events in the future. Astrodynamics forensic analyses, the sleuthing techniques used to gather an event's known details and estimate its unknown parameters, can be used to develop theories about the causes of a breakup and to predict its consequences.</span></div><div>In the past five years, several on-orbit collisions and explosions have occurred, involving a variety of orbiting objects with varying amounts of available observational data. Techniques and tools developed over decades at The Aerospace Corporation are used to characterize key parameters of these events, including spread velocity of the debris pieces, energy involved in the breakup events, and mass and area estimates of the individual debris fragments. These forensic capabilities are enhanced by utilizing patterns identified from different classes of historical breakups and ground-test data. This paper shows the effectiveness of this methodology when used for analysis of a variety of event types including collisions, such as the Cosmos 1408 ASAT test and SL-14 rocket body breakup, rocket body fragmentations such as the 2022 Long March 6A breakup, and satellite fragmentations such as the Resur-O1 breakup. Representative models of events are developed using the IMPACT fragmentation tool, and predictions of the lifetimes of the subtrackable orbital debris are included. Where event sources are unknown, breakup parameters and trends are used to suggest possible causes. The challenges of analyzing an orbital breakup mystery with few observational clues are also discussed.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 388-394"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141845281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-01DOI: 10.1016/j.jsse.2024.08.001
Hugh G. Lewis, Georgia Skelton
The deployment of constellations of satellites within low Earth orbit (LEO) has implications for space operations and for the broader space environment. A large active satellite population will experience high numbers of conjunctions with other resident space objects (RSOs). Even if only a small proportion are high-probability events, the substantial number of conjunctions will still lead to many potentially high-risk encounters with other RSOs and a correspondingly high burden for their operators to mitigate them via maneuvers. This burden is exacerbated if the operator adopts an approach whereby risk mitigation maneuvers are conducted at collision probability levels below the widely accepted 1E-4 (1-in-10,000). Despite these significant efforts the remaining aggregate risk may still be relatively high because of the large number of conjunctions experienced by some constellations, leading to ongoing concern over the safety of these space systems. Through an analysis of conjunction assessment data, simulations using the DAMAGE computational model, and a new mapping approach, the risks from conjunctions between large constellations and other RSOs have been investigated. The results show that some existing constellations currently face more than a 10 % annual collision probability even after accounting for their robust risk mitigation approaches, with implications for the safety and long-term sustainability of large constellations and the broader LEO environment. Overall, the work emphasizes the need for new research and guidance on this aspect of space operations.
{"title":"Safety considerations for large constellations of satellites","authors":"Hugh G. Lewis, Georgia Skelton","doi":"10.1016/j.jsse.2024.08.001","DOIUrl":"10.1016/j.jsse.2024.08.001","url":null,"abstract":"<div><div>The deployment of constellations of satellites within low Earth orbit (LEO) has implications for space operations and for the broader space environment. A large active satellite population will experience high numbers of conjunctions with other resident space objects (RSOs). Even if only a small proportion are high-probability events, the substantial number of conjunctions will still lead to many potentially high-risk encounters with other RSOs and a correspondingly high burden for their operators to mitigate them via maneuvers. This burden is exacerbated if the operator adopts an approach whereby risk mitigation maneuvers are conducted at collision probability levels below the widely accepted 1E-4 (1-in-10,000). Despite these significant efforts the remaining aggregate risk may still be relatively high because of the large number of conjunctions experienced by some constellations, leading to ongoing concern over the safety of these space systems. Through an analysis of conjunction assessment data, simulations using the DAMAGE computational model, and a new mapping approach, the risks from conjunctions between large constellations and other RSOs have been investigated. The results show that some existing constellations currently face more than a 10 % annual collision probability even after accounting for their robust risk mitigation approaches, with implications for the safety and long-term sustainability of large constellations and the broader LEO environment. Overall, the work emphasizes the need for new research and guidance on this aspect of space operations.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 439-445"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper proposes less fuel strategies for space debris removal. To mitigate the risk of space debris cost-efficiently, multi-rendezvous missions are under development. On the other hand, multi-rendezvous missions often require changing orbital planes of removal satellites, which requires a huge amount of ΔV. Therefore, this study focuses on exploiting the J2 perturbation force as an auxiliary force and aims to establish maneuver rules that minimize ΔV consumption while maximizing the benefit of the J2 perturbation. The J2 perturbation equation is explored analytically, which clarifies whether the change in the semi-major axis or the inclination dominates the efficiency of the exploitation. A straightforward criterion is extracted which determines the efficient maneuver based on the initial inclination of the satellite.
{"title":"Less fuel strategies for space debris removal in Low Earth Orbit","authors":"Yuki Itaya , Yasuhiro Yoshimura , Toshiya Hanada , Tadanori Fukushima","doi":"10.1016/j.jsse.2024.08.002","DOIUrl":"10.1016/j.jsse.2024.08.002","url":null,"abstract":"<div><div>This paper proposes less fuel strategies for space debris removal. To mitigate the risk of space debris cost-efficiently, multi-rendezvous missions are under development. On the other hand, multi-rendezvous missions often require changing orbital planes of removal satellites, which requires a huge amount of ΔV. Therefore, this study focuses on exploiting the J<sub>2</sub> perturbation force as an auxiliary force and aims to establish maneuver rules that minimize ΔV consumption while maximizing the benefit of the J<sub>2</sub> perturbation. The J<sub>2</sub> perturbation equation is explored analytically, which clarifies whether the change in the semi-major axis or the inclination dominates the efficiency of the exploitation. A straightforward criterion is extracted which determines the efficient maneuver based on the initial inclination of the satellite.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 476-480"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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