Papers by Kathiravan Thangavel
Advances in Space Research, Jun 1, 2023
Research Square (Research Square), Jun 10, 2021
The thermomechanical interactions of onboard space vehicles is an interesting field of research a... more The thermomechanical interactions of onboard space vehicles is an interesting field of research and study. Since the pioneering paper by Bruno Boley, published in 1954, many authors have given their relevant contribution to the comprehension of phenomena not otherwise investigable if not with a cross-sectoral approach and a multidisciplinary methodology. The anomaly that occurred to the spacecraft Alouette 1, in 1962, marked the beginning of a long series of unexpected events due to unconceivable coupling between the mechanical and thermal behaviour of the system. This work aims to emphasise, by means of a simple model, the basic mechanism responsible for elastic vibrations induced by a thermal shock. This is a widespread event experienced by a spacecraft during the transitions shadow-Sun and vice-versa or when a flexible appendage, previously shadowed by the spacecraft's main body, comes to the light as a consequence of an attitude manoeuvre [Ulysses, 1990]. For the investigation, a very slender structure has been considered in order to make the thermal and mechanical characteristic times comparable and realise the conditions of strong coupling. The accurate thermal analysis provides an equivalent thermal bending moment, depending on time, which appears as a boundary condition in the subsequent modal analysis of the structural element, where it plays the role of a trigger of elastic transverse vibrations.
Aerospace, Jun 18, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Aerospace
Propellant gauging is crucial for a spacecraft approaching the end of its lifespan. Current gaugi... more Propellant gauging is crucial for a spacecraft approaching the end of its lifespan. Current gauging systems for satellites typically have an accuracy rate of a few months to a year at the end of their operational life. Therefore, it is essential to determine the appropriate gauging system for mission operations. This research focuses on modeling the propellant gauging system for PRISMA, an Earth Observation (EO) satellite of the Italian Space Agency. The analysis centers on implementing algorithms that calibrate the remaining propellant mass in the satellite tank using traditional methods such as bookkeeping (BKP) and pressure-volume-temperature (PVT). To enhance accuracy in quantification, an unconventional approach called thermal propellant gauging (TPG) has been considered. Preliminary computations were conducted using data obtained from the PRISMA thermal model to understand the calibration accuracy of the three methods. At the end of its operational life, the BKP and PVT method...
Advances in Space Research
The thermomechanical interactions of onboard space vehicles is an interesting field of research a... more The thermomechanical interactions of onboard space vehicles is an interesting field of research and study. Since the pioneering paper by Bruno Boley, published in 1954, many authors have given their relevant contribution to the comprehension of phenomena not otherwise investigable if not with a cross-sectoral approach and a multidisciplinary methodology. The anomaly that occurred to the spacecraft Alouette 1, in 1962, marked the beginning of a long series of unexpected events due to unconceivable coupling between the mechanical and thermal behaviour of the system. This work aims to emphasise, by means of a simple model, the basic mechanism responsible for elastic vibrations induced by a thermal shock. This is a widespread event experienced by a spacecraft during the transitions shadow-sun and vice-versa or when a flexible appendage, previously shadowed by the spacecraft's main body, comes to the light as a consequence of an attitude manoeuvre [Ulysses, 1990]. For the investigati...
2023 IEEE/AIAA 42nd Digital Avionics Systems Conference (DASC)
IGARSS 2023 - 2023 IEEE International Geoscience and Remote Sensing Symposium
Remote Sensing
The exacerbation of wildfires, attributed to the effects of climate change, presents substantial ... more The exacerbation of wildfires, attributed to the effects of climate change, presents substantial risks to ecological systems, infrastructure, and human well-being. In the context of the Sustainable Development Goals (SDGs), particularly those related to climate action, prioritizing the assessment and management of the occurrence and intensity of extensive wildfires is of utmost importance. In recent times, there has been a significant increase in the frequency and severity of widespread wildfires worldwide, affecting several locations, including Australia, Italy, and the United States of America. The presence of complex phenomena marked by limited predictability leads to significant negative impacts on biodiversity and human lives. The utilization of satellite-derived data with neural networks, such as convolutional neural networks (CNNs), is a potentially advantageous approach for augmenting the monitoring capabilities of wildfires. This research examines the generalization capabil...
Remote Sensing, Jul 17, 2023
2022 IEEE International Conference on Metrology for Extended Reality, Artificial Intelligence and Neural Engineering (MetroXRAINE), Oct 26, 2022
Sensors
Recent developments in Distributed Satellite Systems (DSS) have undoubtedly increased mission val... more Recent developments in Distributed Satellite Systems (DSS) have undoubtedly increased mission value due to the ability to reconfigure the spacecraft cluster/formation and incrementally add new or update older satellites in the formation. These features provide inherent benefits, such as increased mission effectiveness, multi-mission capabilities, design flexibility, and so on. Trusted Autonomous Satellite Operation (TASO) are possible owing to the predictive and reactive integrity features offered by Artificial Intelligence (AI), including both on-board satellites and in the ground control segments. To effectively monitor and manage time-critical events such as disaster relief missions, the DSS must be able to reconfigure autonomously. To achieve TASO, the DSS should have reconfiguration capability within the architecture and spacecraft should communicate with each other through an Inter-Satellite Link (ISL). Recent advances in AI, sensing, and computing technologies have resulted i...
2023 IEEE Aerospace Conference
Remote Sensing
Autonomous navigation (AN) and manoeuvring are increasingly important in distributed satellite sy... more Autonomous navigation (AN) and manoeuvring are increasingly important in distributed satellite systems (DSS) in order to avoid potential collisions with space debris and other resident space objects (RSO). In order to accomplish collision avoidance manoeuvres, tracking and characterization of RSO is crucial. At present, RSO are tracked and catalogued using ground-based observations, but space-based space surveillance (SBSS) represents a valid alternative (or complementary asset) due to its ability to offer enhanced performances in terms of sensor resolution, tracking accuracy, and weather independence. This paper proposes a particle swarm optimization (PSO) algorithm for DSS AN and manoeuvring, specifically addressing RSO tracking and collision avoidance requirements as an integral part of the overall system design. More specifically, a DSS architecture employing hyperspectral sensors for Earth observation is considered, and passive electro-optical sensors are used, in conjunction w...
2022 IEEE International Conference on Metrology for Extended Reality, Artificial Intelligence and Neural Engineering (MetroXRAINE)
Remote Sensing
One of the United Nations (UN) Sustainable Development Goals is climate action (SDG-13), and wild... more One of the United Nations (UN) Sustainable Development Goals is climate action (SDG-13), and wildfire is among the catastrophic events that both impact climate change and are aggravated by it. In Australia and other countries, large-scale wildfires have dramatically grown in frequency and size in recent years. These fires threaten the world’s forests and urban woods, cause enormous environmental and property damage, and quite often result in fatalities. As a result of their increasing frequency, there is an ongoing debate over how to handle catastrophic wildfires and mitigate their social, economic, and environmental repercussions. Effective prevention, early warning, and response strategies must be well-planned and carefully coordinated to minimise harmful consequences to people and the environment. Rapid advancements in remote sensing technologies such as ground-based, aerial surveillance vehicle-based, and satellite-based systems have been used for efficient wildfire surveillance...
Aerospace
Space-based Earth Observation (EO) systems have undergone a continuous evolution in the twenty-fi... more Space-based Earth Observation (EO) systems have undergone a continuous evolution in the twenty-first century. With the help of space-based Maritime Domain Awareness (MDA), specially Automatic Identification Systems (AIS), their applicability across the world’s waterways, among others, has grown substantially. This research work explores the potential applicability of Synthetic Aperture Radar (SAR) and Distributed Satellite Systems (DSS) for the MDA operation. A robust multi-baseline Along-Track Interferometric Synthetic Aperture Radar (AT-InSAR) Formation Flying concept is proposed to combine several along-track baseline observations effectively for single-pass interferometry. Simulation results are presented to support the feasibility of implementing this acquisition mode with autonomous orbit control, using low-thrust actuation suitable for electric propulsion. To improve repeatability, a constellation of this formation concept is also proposed to combine the benefits of the DSS. ...
IEEE Geoscience and Remote Sensing Letters
Climate action (SDG-13) is an integral part of the Sustainable Development Goals (SDGs) set by th... more Climate action (SDG-13) is an integral part of the Sustainable Development Goals (SDGs) set by the United Nations (UN), and wildfire is one of the catastrophic events related to climate change. Large-scale forest fires have drastically increased in frequency and size in recent years in Australia and other nations. These wildfires endanger the forests and urban areas of the world, demolish vast amounts of property, and frequently result in fatalities. There is a requirement for real-time/near realtime catastrophic event monitoring of fires due to their growing frequency. In order to effectively monitor disaster events, it will be feasible to manage them in real time or near real time due to the advent of the Distributed Satellite System (DSS). This research examines the possible applicability of DSS for wildfire surveillance. For spacecraft to continually monitor the dynamically changing environment, satellite missions must have broad coverage and revisit intervals that DSS can fulfill. A feasibility analysis, as well as a model and scenario prototype for a satellite artificial intelligence (AI) system, is included in this letter to enable prompt action and swiftly provide alerts. In our previous research, it is shown that on-board implementation, i.e., data processing utilizing hardware accelerators, is feasible. To enable Trusted Autonomous Satellite Operation (TASO), the same will be included in the proposed DSS architecture, and the outcomes will be provided. To demonstrate the applicability, the suggested DSS architecture will be tested in several geographic locations to demonstrate the system-wide coverage.
2022 IEEE/AIAA 41st Digital Avionics Systems Conference (DASC)
Satellite technologies are used for both civil and military purposes in the modern world, and typ... more Satellite technologies are used for both civil and military purposes in the modern world, and typical applications include Communication, Navigation and Surveillance (CNS) services, which have a direct impact several economic, social and environmental protection activity. The increasing reliance on satellite services for safety-of-life and mission-critical applications (e.g., transport, defense and public safety services) creates a severe, although often overlooked, security problem, particularly when it comes to cyber threats. Like other increasingly digitized services, satellites and space platforms are vulnerable to cyberattacks. Thus, the existence of cybersecurity flaws may pose major threats to space-based assets and associated key infrastructure on the ground. These dangers could obstruct global economic progress and, by implication, international security if they are not properly addressed. Mega-constellations make protecting space infrastructure from cyberattacks much more difficult. This emphasizes the importance of defensive cyber countermeasures to minimize interruptions and ensure efficient and reliable contributions to critical infrastructure operations. Very importantly, space systems are inherently complex Cyber-Physical System (CPS) architectures, where communication, control and computing processes are tightly interleaved, and associated hardware/software components are seamlessly integrated. This represents a new challenge as many known physical threats (e.g., conventional electronic warfare measures) can now manifest their effects in cyberspace and, vice-versa, some cyber-threats can have detrimental effects in the physical domain. The concept of cyberspace underlies nearly every aspect of modern society's critical activities and relies heavily on critical infrastructure for economic advancement, public safety and national security. Many governments have expressed the desire to make a substantial contribution to secure cyberspace and are focusing on different aspects of the evolving industrial ecosystem, largely under the impulse of digital transformation and sustainable development goals. The level of cybersecurity attained in this framework is the sum of all national and international activities implemented to protect all actions in the cyber-physical ecosystem. This paper focuses on cybersecurity threats and vulnerabilities in various segments of space CPS architectures. More specifically, the paper identifies the applicable cyber threat mechanisms, conceivable threat actors and the associated space business implications. It also presents metrics and strategies for countering cyber threats and facilitating space mission assurance.
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Papers by Kathiravan Thangavel