Debris Mitigation Research Articles

Analysis of ODMSP-compliant near-circular GPS disposal orbits and resulting long-term collision risk

The U.S. Government Orbital Debris Mitigation Standard Practices (ODMSP) released in December 2019 include several disposal options that are applicable to GPS satellites. One option is to leave a satellite on a near-circular disposal orbit with limited long-term eccentricity growth. Many currently operational GPS satellites are planned to move to near-circular disposal orbits above the GPS operational constellation and below the BeiDou Satellite System (BDS). The conditions in the ODMSP specify that GPS disposal orbits avoid crossing the semi-synchronous zone (altitude range 20,182 +/- 300 km, occupied by GPS) or the BDS operational altitude for 100 years. An analysis was performed to determine ways to achieve ODMSP-compliance of near-circular GPS disposal orbits and limit associated collision risk. Disposal orbit propagations over 100 years were used to determine the available initial semi-major axis (SMA) range for compliant disposal orbits. Next, the GPS constellation and satellite disposals were simulated over a 200-year time frame. The disposal orbits were propagated and the collision probability between disposed satellites was then evaluated. Results show an available initial SMA range of 363 km for an initial eccentricity of 0.0003 and a range of only 3 km for an initial eccentricity of 0.001, which cover worst-case eccentricity growth scenarios. Results also show that a disposal strategy with initial eccentricity of 0.0003 and initial SMA uniformly spread over 363 km has the lowest collision probability for future disposed GPS satellites.

Improving international governance of space debris in the era of large constellations of small satellites and China’s response

The rapid development of large constellations of small satellites will inevitably lead to a sharp increase of space debris, and thus brings about great threat to space safety and space environment. This poses severe challenges to the current international governance of space debris. The existing space debris mitigation guidelines are neither adaptive nor effective in dealing with the space debris problem in the era of large constellations of small satellites. Under such background, it is indispensable to establish an innovative space debris governance mechanism combining rules both concerning space debris mitigation, prevention, and more importantly, space debris active removal. In this regard, China has been improving its domestic space legislation regarding space debris management at the domestic level. On the other hand, China shall continue to promote the innovative development of space debris governance mechanism at the international level, so as to cope with the conundrums resulting from the development of large constellations of small satellites.

Post-mission de-orbiting of Cartosat-2

India has been voluntarily following the guidelines on space debris mitigation recommended by UN-COPUOS (United Nations Committee on the Peaceful Uses of Outer Space) and IADC (Inter-Agency Space Debris coordination Committee) to the maximum possible extent towards safe and sustainable operations in outer space. As a part of the ongoing efforts for better compliance with these guidelines, post-mission disposal of Low-Earth-Orbit (LEO) objects has been carried out in the recent past. Cartosat-2, which was operational at 630 km altitude, is the first satellite to be de-orbited at its end-of-life through a series of perigee reduction orbit maneuvers to minimize its presence in the LEO region. Consequently, the post-mission orbital lifetime was reduced from more than 30 years to less than 5 years in compliance with the 25-year rule recommended in IADC space debris mitigation guidelines. The de-orbiting exercise utilizing left-over propellant also achieved the objective of minimising any accidental break-up risk. This paper outlines the relevant analyses and planning aspects of post-mission de-orbiting for Cartosat-2. The lessons learnt and recommendations on post-mission disposal for future LEO missions are also presented.

Collision avoidance of satellites using ionospheric drag

50,000+ satellites are scheduled for launch by 2030, bringing both massive opportunities and equally massive challenges. Key among these challenges is the ability to sustainably operate Low Earth Orbit (LEO) spacecraft in an increasingly congested environment where collision avoidance manoeuvres are routine and fuel is limited. This paper explores the application of ionospheric drag as an alternative, propellantless collision avoidance mechanism for satellites with altitudes ranging between 350 and 500 km. This is achieved through the use of an in-house propagation suite developed to support UNSW Canberra Space’s in-orbit Ionospheric Aerodynamic Experiment (IEX) on the M2 spacecraft (NORAD ID: 47967 & 45727). The relative impact of neutral (thermospheric) to charged (ionospheric) drag on along-track separation for a range of spherical bodies with surface potentials ranging between 0 V to -100 V with respect to a quasi-neutral freestream plasma was investigated. This provides a first-order indication of the potential effectiveness of ionospheric drag for collision avoidance based on prior numerical and ground-based investigations into ionospheric drag. The Debris Risk Assessment and Mitigation Analysis software from the European Space Agency was also harnessed to discern the relative performance of both the charged and flared attitude satellites against a common control satellite. The ESA stipulates that a Collision Probability Level value greater than the accepted value of 1E−04 between two satellites requires a risk avoidance manoeuvre, with a conservative approach requiring manoeuvres for values greater than 1E−05. For all test regimes at 350km altitude, at least a 60% reduction in time to achieve the NASA approved risk reduction factor of 31.6 at the time of closest approach for a pre-manoeuvre Collision Probability Level of 2.8E−05 was achieved when using the flared neutral method in comparison to the feathered charged method. Based on these results, this paper finds that ionospheric drag may represent a useful alternative propellantless collision avoidance mechanism for satellites within the altitude range of 350 to 500 km. Future work is needed to refine ionospheric drag models and consider the absolute effectiveness of using ionospheric drag at higher altitudes and in tandem applications to the flared arrangement.

The IMPACT satellite fragmentation model

IMPACT is a hypervelocity collision and explosion model developed by The Aerospace Corporation to predict the characteristics of debris generated by fragmentation events. Used for over 30 years, it is a semi-empirical model that has supported a wide range of orbital debris analyses including satellite risk assessment, on-orbit event analyses, flight test and mission planning, debris mitigation and spacecraft design studies, and long-term debris environment evolution and space safety analyses. The model interconnects empirical expressions with conservation laws and boundary conditions to model debris generation from individual fragmentation events.A series of efforts to study available on-orbit data and newly-generated ground-test data during the past decade has added to the understanding of on-orbit fragmentation events, particularly with regard to explosion events, sub-catastrophic breakups, smaller fragment characteristics, and more diverse modern satellite construction materials. These insights have led to several upgrades of the IMPACT collision and explosion model. The model's capabilities have been expanded to represent sub-catastrophic and asymmetric fragmentation events, more accurately model fragment material differences and their relationships to area-to-mass ratios, model smaller fragments, and relate ground-based and on-orbit data. Additional insights have been gained through the integration of individual model improvements while maintaining overall model consistency.This paper provides an overview of the current IMPACT model, discussing the design and expressions used in the current collision and explosion algorithms, changes over the past decade, and implications of insights from both on-orbit and ground test data. Modelling techniques discussed include representation of fragmenting object material differences, sub-catastrophic fragmentations, and small fragment modelling. Interactions between different model improvements are discussed, including small versus large fragment characteristics and sub-catastrophic versus catastrophic fragmentation events. Model updates are considered in the context of fragmentation event data. Future directions for development also are considered based on the insights from the aggregated data and model updates.

Space Debris Mitigation Using Drag Augmentation Device: A Review

Abstract: The commercialization of space has resulted in a significant increase in the frequency of spacecraft, which is adding to the already large number of objects in orbit. Therefore, future and present missions are at risk from space debris. Most of these spacecraft in orbit have very limited means of mitigation control systems. As a result, certain international regulations are imposed to obtain a license for a spacecraft for launch purposes. The necessity of a feasible debris mitigation technique enables future space missions to be safe and sustainable. This review sheds light on the drag augmentation devices such as dragsail, which can provide an effective means for accelerating the deorbiting process during the EOL phase, making space safe and sustainable without the risk of space debris. Keywords: Dragsail, Ballistic coefficient, Deorbit duration, Space debris, Low Earth Orbit

Charged space debris induced nonlinear magnetosonic waves using inertial magnetohydrodynamics

The excitations of nonlinear magnetosonic waves in the presence of charged space debris objects in the low Earth orbital (LEO) plasma region are investigated by taking into account the effects of electron inertia in the framework of classical magnetohydrodynamics (MHD); which is also referred to as inertial magnetohydrodynamics. The magnetosonic waves are found to be governed by a forced Kadomtsev–Petviashvili (KP) equation with the forcing term representing the effects of space debris objects. The dynamical behaviours of both slow and fast magnetosonic solitary waves are explored in detail. Exact pinned accelerated magnetosonic lump wave solutions are shown to be stable for the entire region in the parameter space of slow waves and a large region in the parameter space of fast waves. In a similar way, exact pinned curved magnetosonic solitary wave solutions become stable for a small region in the parameter space of fast waves. These exact solutions with special properties are derived for some specific choices of the forcing debris functions. These novel results can have potential applications in the scientific and technological aspects of the space debris detection and mitigation in the near-Earth space.

Out of sight, out of mind? The proliferation of space debris and international law

AbstractThe quantity of man-made space objects, ranging from abandoned launch vehicle stages to fragmentation debris, is remarkable. At the time, the drafters of the Outer Space Treaty did not (and perhaps could not) anticipate how great the problem of debris in outer space would one day become. As a result, they only drafted general provisions for the protection of the space environment which are generally deemed insufficient. This article aims to demonstrate that both general rules of international law and the UNCOPUOS Debris Mitigation Guidelines come to the rescue in addressing the space debris issue as they complement and complete the general obligations contained in the Outer Space Treaty. Particular attention is paid to anti-satellite weapon tests, which have catastrophic consequences in terms of creating debris but nonetheless continue to be carried out. Finally, it ascertains whether an obligation on states to actively remove their space debris exists.

초소형위성의 폐기 기동을 위한 항력 증대 장치 개발

In this paper, we described the development of a drag augmentation device for nanosatellite. Recently, space industry has entered the New Space era, and barriers to entry into Low Earth Orbit (LEO) for artificial objects such as small rockets and nanosatellite mega constellations have been significantly lowered. As a result, the number of space debris is increasing exponentially, and it is approaching as a major threat to satellite currently in operation as well as satellites to be launched in near future. To prevent this, international organizations like Inter-Agency Space Debris Coordination Committee (IADC) have been proposed space debris mitigation guidelines. The Korea Aerospace Research Institute (KARI) conducted KARI Rendezvous & Docking demonstration SATellite (KARDSAT) project, the first nanosatellites for rendezvous and docking technology demonstration in Korea, and we also developed drag augmentation device for KARDSAT Target nanosatellite that complied with the international guideline of post-mission disposal.

The Problem of Space Debris, Mitigation of Space Debris as an Obligation and the Remedies Seen so Far

The Problem of Space Debris, Mitigation of Space Debris as an Obligation and the Remedies Seen so Far

The Use of Law to Address Space Debris Mitigation and Remediation: Looking Through a Science and Technology Lens

Increasingly over the past six decades, space exploration and technology have revolutionized the world we live in. The land- scape in outer space has continued to evolve rapidly, presenting new challenges for a much slower moving legal framework as well as for peaceful uses of space more generally. In particular, space debris has emerged as a pressing global threat. In response, states have shifted towards a more informal two-pronged approach to outer space, as reflected by non-binding instruments adopted by the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS), along with the development of technologies that aim to provide practical solutions to space debris concerns. Taking into account these strategies, this Article first undertakes a review of various complexities facing the existing regulatory framework regarding the environment of space with a focus on dual-use technologies. The Article then demonstrates how Science and Technology Studies (STS) perspectives may offer frameworks and approaches that allow legal scholars to approach highly networked and entangled questions in ways that offer new paths forward while also facilitating technical legal analysis. By doing this, we hope to emphasize that a more multi-disciplinary perspective regarding the complexities and challenges associated with increasing levels of space activities is both warranted and constructive.

Space Debris Mitigation: Some Lessons from International Environmental Law

The Soviet Union successfully launched Sputnik I in 1957 which led to the era of space activities. Although human race has benefited numerous from space activities, unlimited use of outer space has caused pollutions in outer space and consequently at the earth environment. Space debris has become a threat to the security of space activities. Space debris is the most important of these pollutions that, not only creates numerous threats and risks for Orbiting Satellites, It also has harmful effects on earth environment. During drafting UN space treaties, little attention was paid to environmental problems and these treaties did not mentioned of space debris and its hazards. in recent decades, Ethics of Outer Space activities, paid more attention to the environment of outer space and environmental issue of space activities. Therefore, the experiences of environmental law and its preventive policies can be used to reduce the threat of space debris for peaceful space activities and the environment of space and planet Earth.

Floating marine debris mitigation by vessel routing modeling and optimization considering carbon emission and travel time

Macro-marine debris becomes a global thorny issue to human beings and people are keeping trying every means to mitigate the risk of it. In this paper, we propose to use vessel and develop optimal vessel routing network to collect macro-marine debris on the nearshore surface. Due to the integrated force of winds and ocean currents, debris constantly changes floating location in the ocean. Advanced remote sensing technology and General National Oceanic and Atmospheric Administration (NOAA) Operational Modeling Environment (GNOME) software are employed to identify debris locations and track the drifting trajectory, respectively. In order to balance collecting efficiency and vessel emission reduction, we propose a bi-objective mixed integer nonlinear programming model for vessel routing to minimize travel time and carbon emission, considering time window at debris location, vessel capacity, low/medium/high vessel speed, and cost including carbon tax. A novel pheromone heuristic adaptive large neighborhood search (PHALNS ) algorithm combined with archived multi-objective simulated annealing (AMOSA) mechanism is developed to solve the proposed model. The Yangtze River Estuary region is taken as a numerical example to verify the proposed model and algorithm. Six criterions are introduced to evaluate the best collection time, and the proposed algorithm is also compared with NSGA II algorithm. The results show that low carbon emission and cost effective could be achieved simultaneously, and vessel speed has larger impact than the route scheme.

Space Debris Mitigation and the Brazilian Foreign Space Policy

This article addressed the importance of adopting space debris mitigation strategies based on Brazilian government policy. Key findings pointed out that space debris is an issue with social, environmental, and economic impacts on global scale. Additionally, the Brazilian Government guarantees national security and establishes its aerospace sovereignty. Findings pointed out the relevance of space debris mitigation as a crucial government policy to address the creation of general Brazilian space law, as well as the opportunity for investments in the space sector as a whole in order to provide the training of civilians and military in the development of equipment to remedy the problem. Discussion on case implications and future research recommendations compile the present work.

Marine debris database development using international best practices: A case study in Vietnam

Marine debris, particularly plastic debris is a ubiquitous global pervasive problem. The international community recognizes that a reduction in plastic debris density is central to sustainable ocean use based on reduction performance metrics. Although many national databases already exist or are being developed, an internationally accepted index of plastic debris density does not currently exist. Standardized methods for monitoring marine debris can help inform policy decisions to reduce sources marine debris and support mitigation effectiveness.Vietnam recently committed to addressing marine debris nationally and internationally and developed ambitious targets to manage and reduce ocean plastic debris, yet Vietnam does not currently have a national marine debris monitoring database. This study identified international best practices and standards; developed a marine plastic database for accurate, efficient information gathering, management, and reporting; and developed a centralized database platform for future marine plastic debris management in Vietnam that can be adapted for other jurisdictions.

Space Debris Mitigation and Remediation: Historical Best Practices and Lessons Learned for Economically Preserving and Utilizing Common Areas

Space debris is an increasing problem. Unlike terrestrial debris, there are no natural systems, other than exponentially diminishing atmospheric drag, to self-correct. This creates a self-perpetuating problem that worsens over time as debris collisions create more debris. This danger is exacerbated by the exponential rise in space assets from small satellites and mega constellations, projected to increase >30-fold this decade. Detection and mitigation strategies to monitor and reduce the level of space debris carried out by NASA, UNCOPUOUS, and others are admirable. They are likely a key component of any long-term strategy for space debris management. However, due to the physical nature of space debris propagation, they cannot address current problems alone. Space debris removal and remediation must be implemented in parallel to these systems. Currently, space debris removal is economically, legally, and technically infeasible. Fundamentally, this is a textbook example of a tragedy of the commons created by the self-serving actions of individuals in a shared space creating detrimental conditions for others sharing the same common resources. The purpose of this article is to find viable economic strategies that create a greater marginal benefit than marginal cost for space debris remediation. Then, exploring what legal changes, modifications, or provisions would be needed nationally and internationally to implement these economic strategies. Only after the necessary economic and legal steps have been taken can space actors move to technically address this problem—something beyond the scope of this article. To find possible paths forward, this article uses case studies to analyze the economic and legal strategies employed to address different terrestrial tragedies of the commons scenarios, particularly those in maritime settings, comparing the applications of these outcomes with current conditions in space. Case studies focus on examples in which government and private actors have worked to successfully address large public negative externalities profitably without major disruption to business practices. Finally, this article reviews some of the unique challenges of space law, weakly defined property rights, and intellectual property concerns, and their parallels and differences to the foundational law of the sea precedent. Nations and private actors are moving forward despite the mentioned concerns, pushing and testing the boundaries of what is acceptable whether the laws support them or not. A viable economic solution must be found to support the legal, institutional, and economic aspects of space debris detection, mitigation, and removal.

Assessment of time spent in the LEO, GEO, and semi-synchronous zones by spacecraft on long-term reentering disposal 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. Long-term reentry is beneficial for orbital debris mitigation because it offers a large reduction in long-term collision risk in the regions above low Earth orbit (LEO) compared to use of storage disposal orbits. As a condition for use of this option, the ODMSP specifies a 25-year limit on cumulative time a disposed spacecraft can spend in designated altitude zones that are frequently used by operational spacecraft. An analysis was performed to determine the time spent by disposed spacecraft in the geosynchronous (GEO) zone, the LEO zone, and the semi-synchronous zone for three classes of reentering disposal orbits above LEO: (1) near-circular inclined geosynchronous orbits (IGSOs), (2) eccentric IGSOs (Tundra orbits), and (3) GPS orbits. Long-term disposal orbit propagations over 200-years were performed using the Aerospace high-precision integration code TRACE. Collision probability with operational satellites in the various zones is determined using the Aerospace Debris Environment Projection Tool suite in order to check the trend with time in zone. Results of the study showed that time in zones is less than 25 years when orbital lifetime is less than 200 years, thereby clearing the way for using the new long-term re-entry option relative to this condition. The absolute numerical value of collision probability with operational satellites was found to vary substantially with disposal orbit case and zone. For most cases, results show a clear trend between time in zone and collision probability with some spread. An exception is the GEO zone, for which results show a trend but a wide spread. This may be because most GEO satellites are confined to a ring instead of the shell represented by an altitude zone.

Optically transparent thin film usage in FOD sensitive enclosures

We present a portable test setup used as a ground support equipment for the Solar Ultra Violet (SUVI) instrument on GOES-R series of satellites. The test setup is used as part of “remove before flight” or to package optical components for “install before flight”. The portable setup utilizes an inexpensive, commercially available thermo-plastic film that provides excellent barrier for moisture and debris. In addition to providing Foreign Object Debris (FOD) mitigation, this thermo-plastic film exhibits 1/10th wave optical performance. Most precision optical testing of instruments or subsystems can occur without exposing the systems to the environment.

Empowering the UAE Space Sector Through an Attractive Regulatory Framework

The United Arab Emirates (UAE) leadership has realized the increasing importance of space. Hence, it has been investing in space science and technology since the 90s, and has been able to develop a diverse space sector, and compete globally. Recognizing this importance, the UAE developed its legal framework to regulate the UAE space sector. This article will highlight the establishment and mandate of the UAE Space Agency (UAESA), the local and global growth of the space economy, the UAE’s regulatory approach, and the objectives of Federal LawNo. 12 of 2019 on the Regulation of the Space Sector (the UAE Law). It will address the UAE’s regulations regarding space activities and other activities related to the space sector, the initiatives to attract more space activities and investment, transparency and sustainability of space activities, the scope of the UAE law, and the scope of regulated activities and space-related activities. In addition, some fundamental topics covered by theUAE Law will be discussed, such as authorization, registration, third-party liability and insurance. Lastly, some new subjects covered by the law will be highlighted, like space debris mitigation, extraction and utilization of space resources, human spaceflight and tourism, and nuclear power sources. the UAE Space Law, attractive regulations, space economy, UAESA, sustainable space activities

Drag augmentation systems for space debris mitigation

Space debris is a critical threat to future and on-going missions. The commercialisation of the space sector has led to a rapid growth in the number of small satellites in recent years, which are adding to the already high number of objects currently in low-Earth orbit (LEO). Low-cost small satellites operators are under increasing pressure to comply with debris mitigation guidelines as part of the application process for a launch licence. Drag augmentation systems are a potential low-cost and low-impact solution for small satellites. By increasing the effective area of a satellite, and therefore its drag, these sails reduce the de-orbit period of a satellite, subsequently reducing the probability of significant collisions and supporting the sustainable use of space. Cranfield University are developing a family of drag augmentation systems (DAS) to assist in the long-term conservation of the space environment. The DAS are lightweight, cost-effective, reliable sails deployed at end of mission. Currently three of the drag sails designed, manufactured, and tested at Cranfield University are in orbit and two of the devices have successfully deployed their sails. This paper will discuss these sails and will highlight results from recent studies; examining the scalability of the system, the vehicle dynamics after sail deployment, the medium-term impact of the sail on the host satellite's ability to continue operations, and the long-term effect of the sail on the demisability of the satellite. The DAS technology has a strong enabling potential for future space activities, allowing satellites to operate responsibly and sustainably.