Journal of Space Safety Engineering最新文献

Among the unmanned launch service providers, the autonomous flight termination concept is no longer an unknown actor around the table. The goal of these systems is to limit the consequences of the potential feared events caused by a launch vehicle malfunction by automatically terminating the flight of the vehicle in a safe manner, replacing the human component on the traditional flight termination decision in case of failure.

Although some public and private players have already designed (and even flown) an autonomous flight termination system, the problem arises when looking into the safety standards that need to be to be applied to launch from different locations, which are highly dependent on the respective safety authorities.

This paper aims at analysing the gap in the current launch safety policies and proposing the guidelines to be followed to widen the range of spaceports capable of hosting a launch vehicle with such a feature.

Over the past 30 years, numerous methods and tools have been developed to simulate spacecraft breakup during atmospheric re-entry, predict the characteristics of the surviving fragments, and estimate the ground casualty risk. With the introduction of the Design for Demise (or simply D4D) concept, these tools have become increasingly vital in designing spacecraft that break up and burn up during re-entry, thus reducing the risk posed by impacting debris. To enhance the accuracy and efficiency of predictions, researchers have made continuous improvements in this field, especially in the last decade, but uncertainties and gaps in knowledge remain. This article provides an overview of the state-of-the-art, with a particular emphasis on tools developed in Europe. It covers the latest advancements and improvements, as well as novel techniques proposed in the field.

All spacecraft use some sort of thermal insulation, or thermal protection system (TPS), in their design. TPS materials vary, ranging from ceramic tiles or phenolic ablators for heatshields to lightweight multi-layer insulation (MLI) blankets. Since TPS is usually placed on the spacecraft's exterior, it is susceptible to impacts by meteoroids and orbital debris. These high-speed impacts can damage the TPS to a point where the protection it offers is below acceptable limits. As such, it is important to be able to characterize expected TPS damage levels stemming from such high-speed impacts. In this paper, we present the results of a study that sought to characterize the high-speed impact damage that would be sustained by two TPS materials that have recently gained attention for possible use in future interplanetary missions. Empirical equations were developed for TPS crater depths, as well as maximum and minimum crater mouth dimensions. In the event of TPS perforations, empirical equations were developed for the maximum and minimum through-hole dimensions. As part of the analyses performed, ballistic limit equations (BLEs) for these TPS configurations were also developed where possible. The validity of the equations developed was assessed by comparing their predictions against test data. In nearly all cases, the empirical equations developed herein were seen to adequately capture the magnitudes of the measured damage parameters.

The population of objects in space has increased dramatically over recent decades. Space debris now represents the majority of objects in space resulting from inactive satellites, breakups, collisions and fragmentations. It has become a concern for institutions all over the world and, as such, it has led to the fostering of several programmes to counter the issues. Among these, the use of ground-based sensors for Space Surveillance Tracking (SST) activities and services and tools for analysing fragmentations play a crucial role.

This work presents the activities carried out by Politecnico di Milano, Italian Space Agency and Italian National Institute of Astrophysics in this framework, using data from SST networks and the observation measurements from Bistatic Radar for LEo Survey (BIRALES), an Italian bistatic radar belonging to the EUropean Space Surveillance and Tracking (EUSST), which contributed most to the monitoring of the cloud of fragments. Exploiting Two-Line Elements (TLEs) of observed fragments, a reverse engineering approach is used to reconstruct a fragmentation in orbit through the use of the software suite PUZZLE developed at Politecnico di Milano. The analyses focus on studying the fragmentation of the Cosmos 1408 satellite, which occurred on November 15th 2021 following an Anti-SATellite (ASAT) missile test. More than 1000 trackable pieces and millions of smaller debris (estimated from numerical analysis) were produced by this event, increasing the population of inactive objects around the Earth, and threatening nearby orbiting objects.

First, the processing method adopted from BIRALES in observing Cosmos debris is presented and discussed and a critical analysis about the derivable information is conducted. Then, these data and those from SST network observations are used to identify the epoch and the location of the fragmentation. In this procedure, the software toolkit PUZZLE, developed by Politecnico di Milano within a project funded by the Italian Space Agency and extended through the European Research Council, is used.

The article provides a thorough characterization of wartime space activity, which has grown and evolved significantly over the past six decades. It is substantiated that the utilization of space under the auspices of several space states has turned into a type of activity in more than 60 countries around the world. Authors carried out a study of trends in the sources of funding for the space industry, as well as identified negative factors that affect the pace of development of the space industry established in previous years, namely: problems in the world economy caused by the introduction of sanctions against the Russian Federation, inflation rates, changes in interest rates and loss Ukraine's export opportunities. We studied the European Space Agency report on changes to funding amounts for space sector projects that fit the definition of projects with rapid development for the years 2019–2022. The impact of the conflict on Ukraine's space industry and strategies for maintaining pre-war accomplishments under novel circumstances are identified. The process via which the government and private businesses fund domestic space activities is examined. The purpose of the article is a thorough analysis of the pre-war and post-war financing of space activities, as well as the formulation of the main models of financing the space industry in the post-war period in order to bring it to a new level of functioning. The research underscores space activity as a major financing priority in developed nations. Pre-war, the space industry showed rapid growth, initially state-funded, later attracting private investments. However, ongoing conflict in Ukraine led to reduced funding for less profitable projects, emphasizing the need for a balanced strategy using state and private investments for post-war reconstruction and maintaining a strong national defense capability in the global space sector.

In order to evaluate the possible casualty area caused by the atmospheric re-entry of a vehicle, CNES develops its own certification tool named DEBRISK. For more than 7 years, an important work has been carried out in the frame of DEBRISK v3 with the aim of reducing as much as possible the uncertainties on all the models influencing the survivability of debris.

Given the significant advances in terms of modelling and observations from ground experiments, the methodologies and recommendations are evolving and improving. Several recommendations are discussed, specifically related to how to model a satellite and problematic equipment from a survivability point of view. Representative satellite test cases are presented, showing the evolution of the debris survivability with DEBRISK V3.

Several commercial companies, as well as various nations, have proposed to deploy or are deploying many satellites in Low Earth Orbit (LEO). These large constellations will greatly increase the number of satellites operating in relatively narrow altitude regions of space. The added space traffic in these regions will create many close approaches between the members of the large constellations and other space operators. These close approach situations can necessitate maneuver(s) to avoid a potential collision. Should both satellites have maneuvering capability, the question of how the overall collision avoidance procedures should be executed is raised. Some constellations may employ automated collision avoidance systems which interact differently than conventional human-in-the-loop systems. Interactions between an automated system and another operational satellite, between two automated systems or two nonautonomous systems present new challenges for executing effective collision avoidance. Additionally, the existence of non-maneuverable satellites and space debris continues to pose additional challenges. This paper is the first of several papers that will be documenting an International Academy of Astronautics study on this topic.

Geospatial and celestial datasets are used extensively to support safety-critical applications across multiple industries. Examples include aircraft navigation aids, charts, terrain elevation data, and many others. In commercial space, examples include star positions, micrometeoroid, and orbital debris data (MMOD), terrestrial or lunar navaids, lunar terrain data. Depending on its application, this data has the potential to cause hazards and therefore needs to be assured. Approval of this data cannot be achieved by any one company or body alone; the international commercial space industry needs to develop an ecosystem of interlocking standards and oversight. The aviation industry provides a good example of how this might be accomplished.

Over the last few years, both the space debris population and the number of active satellites in orbit has dramatically increased. The risk of collision for satellite missions is a problem to an increasing extent targeted thoroughly by all agents involved in space situational awareness (SSA) & spacecraft operations. In the frame of the European Union Space Surveillance and Tracking (EU SST), the CA service is provided on a hot redundancy scheme involving the French and Spanish Operations Centres (FR-SSA Centre and S3TOC, respectively), to more than 50 organizations and 390 satellites at the time of writing.

Given the dynamic space environment, EU SST CA service must evolve continuously to face the increase of the number of registered users and spacecraft, the diversity of users’ needs and the increasing number of close approaches.