{"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}
{"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}
{"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}
{"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}
{"title":"Adaptive relative orbit control considering laser ablation uncertainty","authors":"","doi":"10.1016/j.jsse.2024.04.007","DOIUrl":"10.1016/j.jsse.2024.04.007","url":null,"abstract":"<div><div>This study proposes a relative orbit control law for laser debris removal missions considering the uncertainties of laser ablation<span><span><span> and atmospheric drag. A removal spacecraft irradiates laser pulses to a target debris to generate the ablation force for deorbiting. The deorbiting force lowers the target altitude, and the removal spacecraft must follow it to maintain its relative position for continuous laser irradiation. The difficulty stems from uncertainties of the magnitude of </span>laser ablation and </span>external disturbances<span><span> such as atmospheric drag. To tackle this problem, this study derives an adaptive control method using the Gaussian process regression to cancel the uncertainties with a nonparametric regression model. Numerical simulations verify the proposed control law under the uncertainties of </span>laser ablation and atmospheric drag. The proposed control law can contribute to the realization of a safer and more secure mission not only for laser debris removal missions, but also for other on-orbit services.</span></span></div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 491-497"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141057226","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}
{"title":"A holistic systems thinking approach to space sustainability via space debris management","authors":"","doi":"10.1016/j.jsse.2024.05.007","DOIUrl":"10.1016/j.jsse.2024.05.007","url":null,"abstract":"<div><div>This paper explores the concept of space sustainability and its interconnections using systems thinking approaches. This is done by highlighting the importance of multi-disciplinary perspectives when creating policies aimed at addressing the complex challenges of sustainability for space-related activities. Causal loop diagrams are employed to highlight the presence of feedback loops and causal relationships that are typically absent in space debris models and are treated as separate systems. A systems representation of the space environment is presented along with a discussion of its role in furthering research relating to the impact of large satellite constellations on factors important for holistic sustainability. This study investigated one example feedback between the space environment and the atmosphere and found that CO<sub>2</sub> emissions specifically emitted from launches and re-entries have no significant impact on atmospheric density below 500 km.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 532-538"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141408580","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}
Nicolas Billot , Stephan Hellmich , Willy Benz , Andrea Fortier , David Ehrenreich , Christopher Broeg , Alexis Heitzmann , Anja Bekkelien , Alexis Brandeker , Yann Alibert , Roi Alonso , Tamas Bárczy , David Barrado Navascues , Susana C.C. Barros , Wolfgang Baumjohann , Federico Biondi , Luca Borsato , Andrew Collier Cameron , Carlos Corral van Damme , Alexandre C.M. Correia , Thomas G. Wilson
{"title":"In-situ observations of resident space objects with the CHEOPS space telescope","authors":"Nicolas Billot , Stephan Hellmich , Willy Benz , Andrea Fortier , David Ehrenreich , Christopher Broeg , Alexis Heitzmann , Anja Bekkelien , Alexis Brandeker , Yann Alibert , Roi Alonso , Tamas Bárczy , David Barrado Navascues , Susana C.C. Barros , Wolfgang Baumjohann , Federico Biondi , Luca Borsato , Andrew Collier Cameron , Carlos Corral van Damme , Alexandre C.M. Correia , Thomas G. Wilson","doi":"10.1016/j.jsse.2024.08.005","DOIUrl":"10.1016/j.jsse.2024.08.005","url":null,"abstract":"<div><div>The CHaracterising ExOPlanet Satellite (CHEOPS) is a partnership between the European Space Agency and Switzerland with important contributions by 10 additional ESA member States. It is the first S-class mission in the ESA Science Programme. CHEOPS has been flying on a Sun-synchronous low Earth orbit since December 2019, collecting millions of short-exposure images in the visible domain to study exoplanet properties.</div><div>A small yet increasing fraction of CHEOPS images show linear trails caused by resident space objects crossing the instrument field of view. CHEOPS’ orbit is indeed particularly favourable to serendipitously detect objects in its vicinity as the spacecraft rarely enters the Earth's shadow, sits at an altitude of 700 km, and observes with moderate phase angles relative to the Sun. This observing configuration is quite powerful, and it is complementary to optical observations from the ground.</div><div>To characterize the population of satellites and orbital debris observed by CHEOPS, all and every science images acquired over the past 3 years have been scanned with a Hough transform algorithm to identify the characteristic linear features that these objects cause on the images. Thousands of trails have been detected. This statistically significant sample shows interesting trends and features such as an increased occurrence rate over the past years as well as the fingerprint of the Starlink constellation. The cross-matching of individual trails with catalogued objects is underway as we aim to measure their distance at the time of observation and deduce the apparent magnitude of the detected objects.</div><div>As space agencies and private companies are developing new space-based surveillance and tracking activities to catalogue and characterize the distribution of small debris, the CHEOPS experience is timely and relevant. With the first CHEOPS mission extension currently running until the end of 2026, and a possible second extension until the end of 2029, the longer time coverage will make our dataset even more valuable to the community, especially for characterizing objects with recurrent crossings.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 498-506"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571564","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}
{"title":"Probabilistic assessment of disposal orbit lifetime for CubeSat rideshares on resonant decaying geosynchronous transfer orbits","authors":"Juan C. Maldonado, Alan B. Jenkin, John P. McVey","doi":"10.1016/j.jsse.2024.07.009","DOIUrl":"10.1016/j.jsse.2024.07.009","url":null,"abstract":"<div><div>Recent years have seen an increase in CubeSat missions on rideshares to geosynchronous orbit. The typical practice for these missions is to deploy the CubeSat on a geosynchronous transfer orbit (GTO) which results in a perigee altitude that is low enough that atmospheric drag will cause the apogee altitude to decay and eventual reentry. However, for GTOs, demonstrating compliance with limits on orbital lifetime in orbital debris mitigation guidelines is not straightforward due to a solar resonance phenomenon that exists which can cause high variability of the orbital lifetime of the satellite. This paper presents a procedure for determining the likelihood that orbital lifetime of a rideshare CubeSat on a resonant GTO will have an orbital lifetime below a 25-year and 5-year limit. The procedure uses a Monte Carlo analysis in which uncertain parameters are randomly varied, including the launch time/initial RAAN and the drag coefficient. The Aerospace precision propagation tool TRACE is used with a high-fidelity force model to enable precision integration through the atmosphere at perigee. It is shown in the study that there is a systematic variation in likelihood of staying below a 25- and 5-year orbital lifetime limit and that drag enhancement devices may be needed to meet the 5-year limit for CubeSat rideshares. The study also presents findings on a solar radiation pressure induced resonance that was observed for high area-to-mass ratios which suggests that there can be a diminishing return when increasing the area of a drag enhancement device to quicken deorbit.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 403-410"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571584","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}
K. Rolf Bohman, Michael A. Weaver, Alan B. Jenkin, John P. McVey
{"title":"Reducing reentry casualty risk for spacecraft on long-term reentering eccentric inclined geosynchronous (Tundra) disposal orbits","authors":"K. Rolf Bohman, Michael A. Weaver, Alan B. Jenkin, John P. McVey","doi":"10.1016/j.jsse.2024.08.008","DOIUrl":"10.1016/j.jsse.2024.08.008","url":null,"abstract":"<div><div>This paper considers disposal of spacecraft and upper stages on eccentric inclined geosynchronous orbits (eccentric IGSOs), specifically the class known as Tundra orbits. The U.S. Government Orbital Debris Mitigation Standard Practices (ODMSP) released in December 2019 include a disposal option to use orbital eccentricity growth for long-term reentry within 200 years that could be used for Tundra orbits. A condition of this disposal option is that reentry casualty risk be limited. An analysis was performed to assess reentry casualty risk for a generic Tundra spacecraft and typical upper stages on Tundra disposal orbits. From propagation sweeps accounting for eccentricity growth of Tundra disposal orbits, several Tundra disposal orbit cases were selected for reentry analysis. A reentry risk analysis for these cases assuming reentry from near-circular orbits was performed. Results show that predicted casualty risk for the generic Tundra spacecraft and typical upper stages well exceed allowable risk limits in the ODMSP. An analysis of reentry from the selected Tundra disposal orbits accounting for the high eccentricity due to eccentricity growth just before reentry was then performed. Results show that the distribution of reentry points on the Earth can be concentrated over ocean in the southern hemisphere where there is less human population. The generic Tundra spacecraft and one of the upper stages considered were then found to be compliant with the limit of 1 in 10,000 expected casualties in the ODMSP. These results indicate promise for wider usage of the long-term re-entry option in the ODMSP.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 481-490"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571563","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}
Andrea Zollo , Giuseppe Di Campli Bayard de Volo , Martin Weigel , Saika Aida , Ralph Kahle , Juan Félix San Juan Díaz
{"title":"Synthetic orbit uncertainty generation through regression analysis of historical Conjunction Data Messages","authors":"Andrea Zollo , Giuseppe Di Campli Bayard de Volo , Martin Weigel , Saika Aida , Ralph Kahle , Juan Félix San Juan Díaz","doi":"10.1016/j.jsse.2024.06.001","DOIUrl":"10.1016/j.jsse.2024.06.001","url":null,"abstract":"<div><div>In the last decades, the Earth-orbiting population of both active and non-active objects has grown significantly, leading to a substantial increase in number of possible in-orbit collisions. It is therefore crucial to monitor the orbit of space resident objects to assess in advance the threat of risky conjunctions. Within this framework, the 18th Space Defense Squadron (SDS) is consistently updating the orbit of thousands of tracked objects by processing observations of the U.S. Space Surveillance Network (SSN). The determined orbital data is continuously maintained in the Special Perturbation (SP) catalogue and used by the 19th SDS to issue close approach warnings to satellite operators around the globe in the form of Conjunction Data Messages (CDM). The Flight Dynamics (FD) group of the German Space Operation Centre (GSOC) receives on regular basis a subset of the SP catalogue data along with CDMs associated to the fleet of its controlled satellites. The SP ephemerides are in fact provided without any covariance information preventing any computation of the Probability of Collision (Pc). In GSOC FD we are implementing a service to link a series of synthetic orbital error covariance matrices to a given SP ephemeris by statistically analyzing historical CDMs of past events. More than 30 GB of past conjunction data are processed to extract state vector, covariance matrix and object size parameter of already encountered secondary objects. The orbital errors of these last are subsequently categorized and divided into orbital classes to decouple the high correlation the covariance has with respect to solar flux, object dimension, altitude of perigee, eccentricity and orbit inclination. The classification aims at collecting similar CDMs regarding the aforementioned dependencies, and approximates the predicted 1-sigma position errors in the orbital frame by optimal curve-fitting techniques. By evaluation of the curve fitting coefficients of a requested orbit class a covariance matrix can be generated for any prediction time in upcoming CDM refinements and other analyses. The work discusses the limiting cases of the classification approach, bringing possible solutions to the scenario of empty classes. An in-depth characterization of the parameters that affect the orbital errors is in fact performed to individualize the neighboring class that provides the closest and most meaningful covariance timeline. Successively, the effect of using synthetic covariance in a conjunction risk assessment is also explored, adapting the problem on real operations. Lastly, the entire data processing pipeline and how the described service fits into the GSOC Flight Dynamics System (FDS) framework is described.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"11 3","pages":"Pages 454-461"},"PeriodicalIF":1.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571561","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}