Journal of Space Safety Engineering最新文献

As we aim for deep space exploration, supporting vital systems, such as the Temperature and Humidity Control System (THCS) in the Environmental Control and Life Support System (ECLSS), through timely onboard fault detection and diagnosis becomes paramount for mission success. Many existing fault diagnosis approaches assume that the function that models the relationship between faults and associated symptoms (fault-symptom relationships) will remain constant throughout the THCS’ lifetime. Therefore, many of these diagnosis methods are not robust enough to automatically account for changes in fault-symptom relationships as a result of changes in the habitat (e.g., system reconfiguration). The work highlighted here is on (i) surveying existing work on adaptable fault diagnosis methods and (ii) showcasing a real-life case study, in which we identified the need for an automatically adaptable fault diagnosis method. The case study focuses on a reconfigured terrestrial THCS analog, the Heating, Ventilation, and Air Conditioning (HVAC) system, where the original fault-symptom relationship is revealed to be no longer accurate. We then apply current adaptable fault-symptom relationship generation methods, such as Model-Based Dependability Analysis (MBDA) methods and data-driven causal discovery methods. Through this analysis, we detail our procedure in (i) identifying relevant fault-free system information, such as redundancy, to revise fault-symptom relationships used in fault diagnosis and (ii) evaluating the fault diagnosis performance in a THCS with the original and revised fault-symptom relationship. Our contribution lies in identifying the shortcomings of current methods and pinpointing future steps in creating an adaptable fault diagnosis framework. We found that although the MBDA methods can automatically generate fault-symptom relationships given system flow information and fault mode of components, they also required manual revision of the aforementioned information to create fault-symptom relationships that reflect redundancies. On the other hand, we concluded that the causal discovery methods can detect fault-free system information, such as redundancies, that may help us revise fault-symptom relationships, but suspect variables that contribute to redundancies may have to be hand-picked.

The capture of the space debris (SD) occurs after the tether is delivered from the space tug (ST) to the SD with the help of an autonomous docking module (ADM). During tether stretching, motion impulses are exchanged between the ST and the "ADM + SD" system, after which a rotating space tether system (RSTS) is created.

Under the influence of two factors, i.e., the difference in relative velocities of the ST and the "ADM + SD" system (up to 200 m/s) and the centrifugal force, significant longitudinal deformations of the tether occur, which can lead to its breakage. The presence of a significant value of the relative velocity projection on the tether line is the peculiarity of this RSTS which has a significant effect on the tether loading in comparison to the action of centrifugal force. In traditional RSTS, only centrifugal forces are considered.

This paper introduces a novel method of damping the longitudinal oscillations of the tether for the proposed type of RSTS, based on two active control strategies: by changing the natural length of the tether and by the thrust force of the ST propulsion system acting opposite to the centrifugal force. A comparative analysis of the dynamics of the RSTS under different methods of active control has been performed.

Significance of the developed methodology is determined by the possibility of using it for further research in planning various active interorbital space missions. The contribution to the solution of the problem under study consists of the possibility of creating RSTS formed by exchanging the impulses of the ST motion and the "ADM + SD" conjunction at significant relative velocities, unlike traditional RSTS, such as star, triangle, etc.

Space is once again an arena of global competition and rivalry, but now more actors and technologies affecting the dynamics. Russia remains a relevant, yet relatively declining space power, eager to preserve both status and capabilities. Space domain is seen as both an opportunity and a threat, and both technological and political efforts are being invested to shape the environment so it will be favorable for Russian interests. However, the interests themselves are defined rather vaguely, yet the threats are seen as immediate, thus some overreaction is a real possibility. The actual and possible developments in the area are researched, and some solutions to keep things manageable are proposed. Moreover, relations of space domain with other major topics, including Strategic Offensive Arms, Missile Defense and Cyber/Electronic Warfare are addressed.

With the success of the Indian Space Research Organization (ISRO) rocket launch on March 26, 2023, Oneweb has made significant progress toward completing its low-Earth orbit (LEO) constellation. Since October 2022, an additional 156 satellites have been added to its constellation, bringing the total number of space assets to 620. This achievement signifies a 98 % completion of the planned OneWeb Gen-1 constellation, that enables high speed and low latency connectivity to high latitude regions worldwide. The full deployment of the constellation is expected to be finalized by mid 2023. As the second world's largest satellite fleet owner and operator, OneWeb prioritizes space safety and sustainability best practices to ensure harmonious co-existence with other space operators within the ever-evolving space environment. Given the substantial increase in the number of space objects over the past two years and the occurrence of fragmentation events, OneWeb aims to share its operational experience and safe navigation methodology of a large satellite fleet from orbit injection to service orbit altitude amid challenges posed by changes in the space environment. The discussion in this paper encompasses various aspects of satellite fleet operations, such as conjunction data management, implementation of space sustainability best practices, and the feasibility and versatility of low thrust electric propulsion systems in satellite maneuverability, environmental pollution reduction and effective collision avoidance efforts.

Over the past few years, numerous accidents have occurred during dangerous chemical experiments. Although there is a considerable amount of literature on laboratory safety, there is still a lack of systematic research that examines how the various laboratory systems interact and potentially contribute to accidents. The objective of this work is to lessen accidents and incidents related to Handling Energetic Materials in Research Laboratories by utilizing STPA (System-Theoretic Process Analysis). This involves examining unsafe interactions between system components, detecting potential undesired events, and implementing measures to prevent or reduce their impact. Recent literature on laboratory safety, quality standards, and interviews with lab workers were used as data sources for the STPA elaboration. As a result, it was possible to identify Unsafe Control Actions, Loss Scenarios, Causal Factors, and Safety Constraints to be considered to avoid undesired events or to mitigate their consequences during the Energetic Material Handling in research centers. It was also possible to point out key measures that can reduce waste, enhance productivity, allocate resources more effectively, decrease accidents, and, most importantly, mitigate potential hazards in laboratory work. The SPTA analysis presented a way to improve laboratory safety management and ensure a safer and more productive research environment.

Hyperloop transportation systems represent an emerging technological frontier with the potential to revolutionize both passenger and freight transportation through high-speed rail transit. However, as is common with nascent technologies, there is no consensus on the best approach to design and operate these systems safely or on the appropriate level of safety integration. Consequently, industry stakeholders find themselves lacking clear regulatory guidance for this rapidly advancing field. Drawing from the wealth of safety expertise developed by NASA over the past several decades in the realm of space exploration, it becomes evident that this robust safety methodology can effectively address safety concerns within the Hyperloop concept. Moreover, it can lay the foundation for a potential certification process that regulatory agencies can adopt. Within this investigation, the safety case approach is applied to scrutinize the Hyperloop system, comparing it to the first published industry standard for Hyperloop systems. By employing this approach, space exploration experience from program development and successful operation as well as from lessons learned from anomaly investigations is leveraged to identify numerous hazards that are not properly addressed from the published standard. This underscores the need for a more comprehensive safety framework to ensure the secure development and operation of Hyperloop transportation systems.

In the very short term, the European Spaceport in French Guiana (CSG) will welcome new kinds of missions and launchers, such as Ariane 6, micro-launchers or reusable vehicles, and must prepare to operate them. At the same time, the launch safety process must be improved in order to maintain flight safety standards and to respect the requirements of the French Space Operation Act (FSOA [1]) regarding the new risks induced. The Flight Safety Department at CSG has been working on the development of new methods to fit these upcoming challenges while enabling the best possible protection to people, the environment and infrastructures. These concepts will be implemented with the arrival of the new Operations Centre (CDO).

Although the flight termination decision remains on a human authority, the process to evaluate the dangerousness of a mission is optimized in order to gain reactivity and effectiveness. As presented at the 73rd IAC [2], this optimization of methods relies on both decreasing the number of operators within the flight safety team during launch operations and on implementing decision-aiding algorithms to better characterize the launcher condition status at any time. This implies a new distribution of the responsibilities between the safety operators and a redesign of the systems in the future organization at CSG.

A large test campaign has already been conducted with the participation of all flight safety officers in order to collect data covering different fields [2]: personal and collective impressions, level of comfort, trust in the new concepts and comparison to the current process, amongst others. In follow-up of this study, to consolidate and validate the operability of the presented concepts and methods, the impacts of this new organization on the flight safety officers have been evaluated in order to apprehend the main changes compared to the current organization. In addition, a specific evaluation was performed in order to study the operator behaviour during various simulations of dangerous-case scenarios in which the launcher trajectory or on-board parameters deteriorated. The most critical cases were analysed in order to measure the reaction times before terminating the flight, with respect to different configurations of launcher abnormality. When comparing the behaviour and the reaction time of operators between the current and the future organization, we obtained conclusive results that are presented in this paper. These results will help to determine and demonstrate the efficiency of the new suggested method for the future flight safety organization at the CSG New Generation. The test campaign presented in this paper was possible following significant ergonomics choices regarding both the flight safety room configuration and the operator HMI layout. Indeed, the enhancement of flight safety operations has been enabled by a careful selection of decision-aiding alg