{"title":"Orbital re-entries of human-made space objects: Drawbacks for the upper atmosphere and the safety of people","authors":"Carmen Pardini, Luciano Anselmo","doi":"10.1016/j.jsse.2025.04.009","DOIUrl":"10.1016/j.jsse.2025.04.009","url":null,"abstract":"<div><div>The controlled and uncontrolled orbital re-entries occurred from 2010 to 2023 were reviewed. Excluding five Space Shuttle orbiters, the total mass re-entered into the atmosphere exceeded 4400 metric tons. In the five-year period 2019-2023, controlled re-entries accounted for nearly 62 % of the returned mass, including 31 % from Falcon 9 second stages alone, while uncontrolled re-entries of intact objects and large debris were responsible for the remaining 38 %. In 2023, the orbital re-entry mass dispersed as gas and particulate in the upper atmosphere was close to 600 metric tons.</div><div>The ground casualty probability associated with the uncontrolled re-entry of satellites, orbital stages and large debris varied, on an annual basis, from 0.8 % in 2010 to 3.5 % in 2023, assuming the complete demise of all objects of less than 300 kg. In 2023, 70 % of the casualty probability was associated with orbital stages, 20 % with satellites and 10 % with large fragments.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 274-283"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365738","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":"Partial heat curing enhancing space debris shielding performance in multi-layered inflatable structures","authors":"Hikaru Takahashi , Yoshihiro Sugiyama , Ryo Kuzuno , Sunao Hasegawa , Kiyonobu Ohtani , Yushin Hara , Kanjuro Makihara","doi":"10.1016/j.jsse.2025.04.002","DOIUrl":"10.1016/j.jsse.2025.04.002","url":null,"abstract":"<div><div>This study proposes a partially heat-cured space debris shield, where only some sheets of traditional multi-shock fabric shields are heat-cured. This approach simplifies on-orbit heat curing as it requires curing a smaller portion of material compared to fully heat-cured inflatable structures. Hypervelocity experiments examined the optimal placement of cured layers within the debris shield, showing that placing them on the upstream side of the first layer maximizes protection performance. This study assessed the protective performance of inflatable structures against space debris collision under consistent areal density conditions, highlighting the improved performance of multi-shock shields subjected to heat curing. Hypervelocity impact experiments revealed that the penetration area of partially heat-cured shields was significantly smaller than that of uncured shields, confirming the benefits of heat curing. We developed spread angle and ballistic limit equations for partial heat-cured shield applications. These equations verified that effective debris protection can be maintained with partial curing, even with reduced standoff. Numerical simulations using smoothed particle hydrodynamics corroborated the experimental results, indicating that strategically placed heat-cured layers enhance protection. Overall, these findings suggest that partially heat-cured shields improve the protection and deployment efficiency of inflatable structures in space.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 253-265"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365736","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":"Front page with the caption related to the front cover","authors":"","doi":"10.1016/S2468-8967(25)00067-9","DOIUrl":"10.1016/S2468-8967(25)00067-9","url":null,"abstract":"","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Page i"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365740","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":"Space applications in manned underwater research stations","authors":"Martin Henke , Frank Scharmann , Michele Rosari","doi":"10.1016/j.jsse.2025.04.001","DOIUrl":"10.1016/j.jsse.2025.04.001","url":null,"abstract":"<div><div>With the new era of manned space travel to the surfaces of other celestial bodies, there is also a need for new simulation possibilities. The advantages of using underwater habitats for this purpose have often been discussed. However, previous facilities such as former habitats, space analogue missions, and training pools have various shortcomings in relation to the new requirements. With a new generation of underwater habitats, these shortcomings can be eliminated by changing the design and using current technologies. Here, we report on the similarities and limitations between extreme environments in space and underwater. Reduced gravity in space is similar to different degrees of buoyancy outside the habitat. Furthermore, stress factors and demands on logistics, technology, and personnel are alike. To simulate longer stays, new focal points are required in terms of the human factor. This includes the ability to add other modules, larger usable areas, and mobility. The American underwater laboratory Aquarius is now only suitable to a limited extent for these new requirements, just like the other approximately 70 habitat projects that have mostly been discontinued. In Calamar Park's interdisciplinary concept of a European Underwater Research Station, all those requirements necessary for the new demands of space travel have been implemented.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 371-376"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365745","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":"Hydrocode simulations of debris impacts on the secondary containment vessel during landing of the Mars Sample Return earth entry vehicle","authors":"Darrel Robertson , Peter Gage , Kelly Carney","doi":"10.1016/j.jsse.2025.04.010","DOIUrl":"10.1016/j.jsse.2025.04.010","url":null,"abstract":"<div><div>NASA sample return missions must satisfy backward planetary protection requirements which include the need to assure robust containment. The Earth Entry System architecture that was in place in December 2023 is passive after release from the carrier spacecraft; the entry trajectory is ballistic, and no parachute is used. At release, the system is targeted to land on soft soil within the Utah Test and Training Range, and displacement of the soil should absorb much of the impact energy. In the unlikely event that the vehicle impacts a hard surface, or a damaged vehicle lands at higher-than-predicted velocity, the heat shield may break and potentially cause debris to impact the Secondary Containment Vessel which houses the samples. This paper describes a set of hydrocode simulations of potential debris items striking the Secondary Containment Vessel, to show that the 2023 design can withstand such impacts and the risk of loss of containment is negligible except at impact velocities in excess of 200 m/s.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 284-292"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365739","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}
Simon Burgis , Hans Rübberdt , Christoph Gaedigk , Louis Keuper , Georgette Naufal , Jonko Paetzold , Xanthi Oikonomidou , Benjamin Bastida Virgili
{"title":"MAS—A mission analysis software for collision risk quantification and impact assessment of rule-based decision-making for collision avoidance","authors":"Simon Burgis , Hans Rübberdt , Christoph Gaedigk , Louis Keuper , Georgette Naufal , Jonko Paetzold , Xanthi Oikonomidou , Benjamin Bastida Virgili","doi":"10.1016/j.jsse.2025.04.007","DOIUrl":"10.1016/j.jsse.2025.04.007","url":null,"abstract":"<div><div>The growing number of operational spacecraft in orbit around Earth results in an increasing operational effort for collision avoidance (COLA), particularly concerning the coordination of COLA measures. In order to cope with this increased effort, the automation of future COLA operations is therefore indispensable. The Mission Analysis Software (MAS) is a web-based application developed at the Technical University of Darmstadt within the project collision avoidance, satellite coordination assessment demonstration environment (CASCADE) which is funded by the European Space Agency (ESA). The MAS promotes a rule-based approach for the automation of COLA coordination within the space community by providing analyses based on data-driven simulations.</div><div>To this end, the MAS enables satellite operators to quantify the risk related to conjunctions involving other active satellites for operational or planned missions. In addition, users of the MAS can conduct a rule analysis showing the impact of incorporating a rule-based coordination approach into operations. To achieve this, users can assemble hierarchical rule sets from pre-defined customisable rule building blocks. The MAS evaluates the operational consequences of a chosen rule set, empowering users to reach bilateral and multilateral agreements with frequently conjuncting parties. With these agreements the obligation to conduct COLA manoeuvres can be assigned automatically for future conjunctions.</div><div>This approach allows for the preemptive reduction of the expected number of conjunctions enabling operators to optimise orbit parameters within their mission constraints as well as the automation of COLA coordination during operations. Through this, the MAS optimises propellant needs, mission time, and required workforce associated with COLA for space missions.</div><div>This paper presents the MAS, highlighting key features developed in close collaboration with stakeholders and the European Space Agency. The workflow for utilising the MAS is briefly outlined, while the primary emphasis of the paper is on detailing the conjunction assessment approach of the MAS.</div><div>For this purpose, the paper presents the uncertainty estimation model of the MAS which is designed to estimate positional uncertainties of satellites based on data from ESA’s <em>Kelvins</em> collision avoidance data challenge. Subsequently, the methodology of the MAS for deriving avoided and remaining risk values and estimated number of manoeuvres for a simulated mission from this uncertainty data is explained showing how operational aspects of COLA are integrated into this process. Lastly, results of the MAS are presented and validated with data from ESA’s DRAMA tool suite.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 338-356"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365749","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":"Collision risk handling at regulatory level, the example of the French space operations act","authors":"Florent Lacomba , Grégoire Laur , Morgane Jouisse , Christophe Taillan","doi":"10.1016/j.jsse.2025.03.003","DOIUrl":"10.1016/j.jsse.2025.03.003","url":null,"abstract":"<div><div>With the issue of congestion of space becoming more and more alarming, many national regulations and international non-binding initiatives are starting to focus on Space Traffic Management needs. STM will indeed be critical in the near future to enable space flight safety, especially through the mitigation of collision risk for maneuverable spacecraft, and more generally the coordination of space activities for all phases of flight. Among these initiatives, France has recently updated its legal and regulatory framework to improve safety and sustainability of space operations performed under its authority, with the publication, on June 28 2024, of a new applicable version of the French Technical Regulation addressing innovative activities and significantly improving collision risk handling. While all recent developments in the field of Space Traffic Management agree on the necessity to better frame collision avoidance practices, the actual implementation within regulations or non-binding instruments may slightly differ and reflect a wide range of possible risk reduction measures. After a brief introduction on the French national law governing space operations, this paper will explore in details the choices made towards the introduction of obligations regarding collision risk management, and highlight their operational implications.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 293-298"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365741","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":"AF advertisement","authors":"","doi":"10.1016/S2468-8967(25)00068-0","DOIUrl":"10.1016/S2468-8967(25)00068-0","url":null,"abstract":"","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Page ii"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365753","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":"Space traffic management","authors":"Katrina Moon , Mark Glissman , Allison Dempsey","doi":"10.1016/j.jsse.2025.04.005","DOIUrl":"10.1016/j.jsse.2025.04.005","url":null,"abstract":"<div><div>Space is a critical link for missions worldwide, including national security, technological development, scientific research, telecommunications, and earth observation. As access to space eases and the market opens, space is becoming increasingly congested. The rapid expansion in the civilian space industry, projected future growth, and increase in orbital debris pose a significant risk to other spacecraft, their missions, and even the orbital shells they occupy. Therefore, the United States, other spacefaring nations, and commercial entities worldwide must work toward the shared goal of maintaining free and accessible space by improved space traffic management. This paper outlines the current state of space traffic management and provides recommendations for a future state to preserve access and utilization of the space domain by all.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 327-337"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365744","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}
Dr. R. Mukesh , Dr. Sarat C. Dass , M. Vijay , S. Kiruthiga
{"title":"Ionospheric TEC forecast using universal kriging and recurrent neural network over low-latitude during the X class solar flares occurred in the year 2024","authors":"Dr. R. Mukesh , Dr. Sarat C. Dass , M. Vijay , S. Kiruthiga","doi":"10.1016/j.jsse.2025.04.008","DOIUrl":"10.1016/j.jsse.2025.04.008","url":null,"abstract":"<div><div>In recent years, Statistical and machine learning models have been widely used for ionospheric total electron content (TEC) forecasting. In this research, we constructed a universal kriging (UK) statistical model and a recurrent neural network (RNN) machine learning model to forecast the TEC during six solar flares that happened in February and March 2024. Twelve months (from February 2023 to January 2024) of geomagnetic indices data like Planetary K Index (Kp), Planetary A Index (Ap), Disturbance Storm Time (DST) index and Solar indices data like Radio Flux at 10.7 cm (F10.7), Solar wind (Sw), and Sun Spot Number (SSN) along with GPS TEC values obtained from the IISC station, Bangalore (13.03° N and 77.57° E) were used for training and two months (February and March 2024) of data were used for testing the constructed models to forecast the TEC during the six solar flares (SF) occurred in the year 2024. The forecasted results showed that the UK model obtained root mean square error values (RMSE) of 6.76 during the X 3.38 SF, 5.58 during the X 2.25 SF, 4.85 during the X 1.9 SF, 7.0 during the X 6.3 SF, 12.29 and 6.74 during the X 1.1 SF when compared to the RNN model obtained RMSE values of 12.81, 14.34, 8.01, 9.39, 14.36 and 11.22 respectively. Analysis of TEC variations during February and March 2024 revealed diurnal patterns influenced by solar radiation, with high TEC values during the day and lesser at night. Comparison of UK and RNN predictions during the SF periods highlighted both models' superior ability to capture TEC variations, particularly at peaks and troughs. The linear regression statistical analysis showed high positive correlations (Pearson's <em>r</em> > 0.96) between actual and predicted TEC for both models, with UK demonstrating higher accuracy during intense solar flares (X6.3 and X3.38). Evaluation during the considered dates for the six SF periods indicated that the UK model provided better overall accuracy compared to RNN, though RNN showed competitive performance. The study underscores UK's potential for precise ionospheric TEC forecasting during solar disturbances, which is essential for space weather monitoring and satellite communication systems. However, the RNN model also performed well during high solar activity suggesting its suitability for capturing abrupt ionospheric changes. This study contributes insights into leveraging surrogate and machine learning models for ionospheric studies, demonstrating their effectiveness in predicting TEC variations under varying solar and geomagnetic conditions. The accuracy of prediction depends upon the size of the data set. This research will be useful to mitigate the positional accuracy errors in the navigation systems and also helpful for improved space communication during adverse solar activities.</div></div>","PeriodicalId":37283,"journal":{"name":"Journal of Space Safety Engineering","volume":"12 2","pages":"Pages 357-370"},"PeriodicalIF":1.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365750","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}