Space Debris Research Articles

Hypervelocity impacts (HVI) from micrometeoroids and orbital debris can produce dense plasmas that may interfere with spacecraft electronics via electromagnetic radiation. This work presents a computational framework to characterize plasma formation during the early stages of an HVI event. A solid-state shock model is used to calculate post-shock, pre-ionized thermodynamic properties for iron-on-iron impacts across a range of velocities (6–50 km/s), employing five different equations of state (EOS). These results serve as inputs to a 0D3V Monte Carlo collision model, which simulates the transient ionization of the shocked material. At low impact velocities (<15 km/s), all EOS produce similar results but diverge at higher velocities due to differences in how they capture phase transitions and quantum effects. The system enters a warm dense matter regime in the post-shock, pre-ionized phase, characterized by strongly coupled ions and moderately degenerate electrons. Ionization occurs on the order of femtoseconds, which is much faster than plasma expansion or electromagnetic propagation over an impactor's characteristic length, validating the assumption of instantaneous plasma formation. We find lower impact velocities will produce partially ionized plasmas, while higher impact velocities will produce fully ionized plasmas, with the threshold defining “low” and “high” velocities depending on the EOS used. Overall, this work provides estimates of temperature, density, and ionization levels immediately after impact, offering improved initial conditions for plasma expansion and radiation models. It also underscores the need for more accurate EOS in extreme regimes and lays the groundwork for future integration with experimental validation and electromagnetic diagnostics in the context of spacecraft missions.

Connecting laboratory and spectroscopic observations of aerospace materials to characterize the reflectivity of artificial space objects and debris in LEO regimes

Optimal placement and coordinated scheduling of distributed space-based lasers for orbital debris remediation

Review on orbital debris mitigation: Techniques for effective tracking, monitoring, and removal

Accurate pose estimation of non-cooperative space objects is crucial for applications such as satellite maintenance, space debris removal, and on-orbit assembly. However, monocular pose estimation methods face significant challenges in environments with limited visibility. Different from the traditional pose estimation methods that use images from a single band as input, we propose a novel deep learning-based pose estimation framework for non-cooperative space objects by fusing visible and infrared images. First, we introduce an image fusion subnetwork that integrates multi-scale features from visible and infrared images into a unified embedding space, preserving the detailed features of visible images and the intensity information of infrared images. Subsequently, we design a robust pose estimation subnetwork that leverages the rich information from the fused images to achieve accurate pose estimation. By combining these two subnetworks, we construct the Visible and Infrared Fused Pose Estimation Framework (VIPE) for non-cooperative space objects. Additionally, we present a Bimodal-Vision Pose Estimation (BVPE) dataset, comprising 3,630 visible-infrared image pairs, to facilitate research in this domain. Extensive experiments on the BVPE dataset demonstrate that VIPE significantly outperforms existing monocular pose estimation methods, particularly in complex space environments, providing more reliable and accurate pose estimation results.

Effects of centimeter-scale irregular space debris active removal by pulsed lasers

Correlation between ballistic coefficients and natural decay times of space debris in very low Earth orbit

Experimental study on in-situ observation technology and protection performance verification of space debris high-speed impact

The goal of this article is to develop a procedure for estimating the deorbit time of used spacecraft and space debris from a nearly circular low-Earth orbit. The paper presents, in a convenient for practical calculations form, an equation of motion of a body along a circular orbit under the action of the atmospheric drag and a given active force. At the observation stage, available online data on the orbit altitude and a model atmospheric density allow one to approximate the ballistic coefficient of the body, which is nearly always unknown in practice. At the estimation stage, the deorbit process is calculated using the approximate ballistic coefficient found previously. The deorbit time calculation error is determined as a function of the duration of the observation and estimation stages for different atmospheric models. The proposed procedure allows one to estimate the minimum acceleration to deorbit the body in a given time. The procedure is validated by calculating the deorbit time of a spacecraft whose uncontrolled flight lasted 16 years: the error is about 10 per cent of the actual deorbit time. The proposed procedure may be used in estimating the life time of space debris objects and in planning the active deorbit of spacecraft at the end of their service life. The proposed procedure may be a basis for future development with account for other interactions between an orbiting body and the space environment.

Space activities are primarily conducted for three purposes: scientific research, human space exploration, and space applications. Over the past few decades, commercial space applications have expanded rapidly and now significantly outpace the efforts of space agencies. Agencies such as NASA have largely shifted their focus away from operational applications, leaving this domain to private enterprise. An emerging domain is the integration of scientific research, exploration, and applications: human space development and cosmic defense. This concept includes initiatives such as mitigating space debris, advancing bio-regenerative life support systems for both Earth and space, and enabling infrastructure for future deep space human settlement and enterprise. This article makes the case for an international coalition of space agencies to spearhead this forward-looking effort aimed at altering the Martian environment to support human life. A core feature of this vision involves developing an artificial magnetosphere. This technology would not only support terraforming efforts but could also lead to the establishment of large-scale human colonies on Mars. The concept extends beyond Mars. If successful, magnetic shielding could also be applied to Earth to mitigate catastrophic solar storms or address the long-term degradation of Earth’s geomagnetic field. These activities could yield critical insights into preserving our biosphere and ensuring the future safety of life on Earth. Three broad scenarios are presented to support human life on Mars. Together, they represent a new, integrative approach to space agency missions, one that supports human expansion into deep space and potentially even the revival of Mars as a living world.

Abstract The growing interest in space exploration, not least for tourism purposes, requires comfortable and visually engaging accommodations in orbiting stations, with large windows to observe the Earth and the cosmos. While seemingly simple, these elements are complex engineering feats, of paramount importance to enhance both the functionality and the human experience of space missions. Designing space windows requires addressing a unique set of engineering demands to ensure safety, durability, and performance under the extreme space conditions. The key requirement is the capacity to withstand the pressure differential between the station’s interior and the vacuum of space, about two order of magnitude higher than in terrestrial applications, without excessive deformation or failure. Furthermore, the glazing is particularly vulnerable to the temperature variations, from the intense heat of direct sunlight to the extreme cold of space, generating cyclically-varying thermal stress that can damage the materials. Finally, space windows must be designed to handle impacts from space debris traveling at high velocities. Other requirements are resilience, high fracture toughness, high endurance limit and lightweight. For these reasons, space glazing are usually composed of several layers, to provide: radiation/thermal shield (multiple plies, vacuum insulated); structural capacity (redundant pressure panes); protection against debris (external pane) and from scratch (internal sacrificial layer). The state of the art in space glazing is represented by the Cupola of the International Space Station (ISS), made of fused silica monolithic flat panels. To address the unique challenges of the space environment, it is not possible to transfer to this context the glazing technology used for terrestrial applications, and innovative transparent composite are necessary. With reference to the windows of the ISS Cupola, taken as paradigmatic examples, we discuss the design, conception, and modeling of high-performance transparent unitized cells for large spacecraft and space station windows, based on operational thermal, optical, and structural requirements.

Japan Aerospace Exploration Agency (JAXA) is developing a debris capture device, HKK for active debris removal by utilizing a caging method to grasp the payload attachment fitting (PAF) of the upper stages of the rockets. The HKK can geometrically constrain all motions of the PAF, except for rotation around the symmetry axis of the PAF ring. To enhance the certainty of capture and complement form closure with a friction-based grip, an additional gripper, namely the PAFgrip, is proposed. This gripper is mounted at the end of the HKK arm; it passively grasps the PAF ring by converting the pushing force from the arm extension through a toggle mechanism. It can maintain the grasp without requiring a power supply, owing to its self-locking function. Additionally, a mechanism for adapting to variations in the thickness of the PAF ring has been designed. A passive release mechanism ensures that the PAF can be released without causing a significant reactive force, and a sensor system is implemented to detect the grasp state. Prototype testing validated that the PAFgrip can reliably grasp PAF rings with a thickness range of 1 mm using the extension force of HKK arm and hold on to the PAF against an external disturbance force of up to 80 N. Furthermore, the PAFgrip can release the PAF passively with a reactive force of less than 3 N, which is approximately 3% of the holding force.

The unprecedented increase in the number of objects orbiting the Earth necessitates a comprehensive characterisation of these objects to improve the effectiveness of Space Surveillance and Tracking (SST) operations. In particular, accurate knowledge of the attitude and physical properties of space objects has become critical for space debris mitigation measures, since these parameters directly influence major perturbation forces like atmospheric drag and solar radiation pressure. Characterising a space object beyond its orbital position improves the accuracy of SST activities such as collision risk assessment, atmospheric re-entry prediction, and the design of Active Debris Removal (ADR) and In-Orbit Servicing (IOS) missions. This study presents a novel approach for the simultaneous estimation of the attitude and optical reflective properties of uncontrolled space objects with known shape using light curves. The proposed method also accounts for atmospheric effects, particularly the Aerosol Optical Depth (AOD), a highly variable parameter that is difficult to determine through on-site measurements. The methodology integrates different estimation, optimisation, and data analysis techniques to achieve an accurate, robust, and computationally efficient solution. The performance of the method is demonstrated through the analysis of a simulated scenario representative of realistic operational conditions.

ABSTRACT Megaconstellation deployment has become a focal point in international discourse, especially between the global powers of the United States and China. This paper investigates China’s and the U.S. strategic approach to deploying megaconstellations in Earth orbit, focusing on the intersection of technological capability and global power dynamics. It scrutinizes sustainability challenges posed by rapid satellite network development, drawing parallels to resource degradation dynamics familiar from terrestrial open-access systems – often described as the “tragedy of the commons”. The study highlights how unchecked megaconstellation growth could lead to orbital congestion and debris, reflecting overuse patterns typical of common-pool resources in shared global domains. Through comprehensive analysis of China’s and the U.S. policies and initiatives, the paper examines the dual-use nature of megaconstellations and their implications for national security and international relations. The research underscores the urgency for a collaborative international framework to regulate space traffic and preserve the long-term viability of Earth orbits. In doing so, it offers a nuanced understanding of China’s stance on space governance and its competitive dynamics with the United States, advocating for a harmonized approach to prevent worsening the tragedy in the celestial commons.

Operational satellites are critical to modern aerospace infrastructure, supporting essential services such as communication, navigation, and global surveillance. However, the increasing density of satellites and space debris in Earth’s orbit has heightened the risk of collisions, thereby threatening network reliability. This study addresses the dual challenge of managing space debris and enhancing satellite network performance by applying the concept of acyclic matching from graph theory to satellite constellations modeled as honeycomb networks. Acyclic matching identifies edge subsets without shared nodes or cycles, enabling static signal rerouting through pre-computed, loop-free paths. This ensures fault tolerance and efficient resource allocation in increasingly complex satellite constellations. The proposed method derives the general solution for acyclic matching cardinality and determines the maximum matching set for n-dimensional honeycomb networks. This technique aligns with emerging trends in autonomous fault-tolerant systems and adaptive routing protocols, proving particularly relevant for large-scale satellite systems such as Starlink and global navigation constellations. By providing alternative communication paths in the event of satellite or link failures, the approach significantly enhances the scalability, reliability, and resilience of satellite networks, ensuring uninterrupted service and improved space traffic management in the face of rising orbital congestion.

Robots and manipulators for structure assembly, spacecraft maintenance and space debris transportation

Despite the wide applications of full-waveform light detection and ranging (FW-LiDAR) on target detection and recognizing, topographical mapping, and ecological management, etc., the mapping between the echo waveform and the properties of the targets, even for typical three-dimensional (3D) targets, has not been established. The mechanics of the modulation of targets on the echo waveform is thus ambiguous, constraining the retrieval of target properties in FW-LiDAR. This paper derived the formula of echo waveform modulated by typical 3D targets, namely, a rectangular prism, a regular hexagonal prism, and a cone. The modulation of shape, size, position, and attitude of 3D targets on the echo waveform has been investigated extensively. The results showed that, for prisms, variations in the echo waveforms under various factors essentially arise from changes in the inclination angles of their reflective surfaces and their positions relative to the laser spot. For cones, their echo waveforms can be approximated and analyzed using isosceles triangular micro-facets. The work in this paper is helpful in probing the modulation of 3D targets on echo waveform, as well as extracting the properties of 3D targets in FW-LiDAR domains, which are significant in areas ranging from topographical mapping to space debris monitoring.

Objective: This article consists of a systematic review of the literature whose objective is to describe the use of Artificial Intelligence in the prevention of collisions between satellites, as well as to characterize the techniques and performances employed to identify critical approaches and plan maneuvers. Theoretical Framework: This review is based on scientific literature on orbital monitoring and AI algorithms obtained from the Web of Science and Scopus databases, using the acronym PICOC to define the keywords that underpin current space collision prevention strategies. Method: This systematic review was conducted in a systematic and impartial manner and reported according to PRISMA guidelines. Results and Discussion: Artificial Intelligence techniques were found to be highly effective in preventing collisions, performing distinct functions, the integration of which enhances the efficiency of the results obtained. Research Implications: The implications of this research provide practical and theoretical support for improving Artificial Intelligence techniques, promoting greater space safety, orbital sustainability, optimized use of resources, and mitigation of catastrophic risks. Originality/Value: The relevance and value of this research are evidenced by providing a solid basis for proposing new solutions.

The utilization of the natural resources of our Moon and the near-earth asteroids (NEAs) for the benefit of humankind will need industrial plants in space. There are a number of possible locations for the deep-space processing of extracted space-based materials and future industrial activities in cis-lunar space. Prime among these are the Moon itself and the Earth’s five Lagrange points which provide equilibrium between the gravity forces of the Earth and Moon. Especially in Lagrange points L4 and L5, objects remain in stable positions because of the triangle between the object, Earth, and Moon. Building the first space factory in L5, for example, will enable the processing of material and production of goods in zero gravity. Unlike on Earth or the Moon, solar power would be available for 24 h. The industrialisation of cis-lunar space will start with the mining of our Moon. The Lagrange Space Factory (LSF) would start with the processing of lunar material and extract aluminum, iron, titanium, and other materials from lunar regolith. When the metals are extracted from oxides, oxygen is a byproduct. An additional source for material would be the recycling of orbital debris to clean up Earth’s orbit. In the long run, the LSF would also process NEA material, including gold, platinum, and carbon. C-type (carbonaceous) asteroids also contain water ice and organic molecules. The goal would be to produce building material like steel bars and aluminum panels, tubes, and bricks for future space habitats. Oxygen and space-made propellant could also be produced. The isotope helium-3 is abundant on the Moon and can be used for future nuclear fusion in space and on Earth.

Background: As the pace of human conquest of space continues to accelerate, the number of spacecraft carrying out various activities in space continues to increase, so that the available orbital space continues to decrease, the amount of space debris continues to increase, and thus the probability of orbiting spacecraft being impacted by space debris is also increasing. Research on the development of protective structures in the current state is conducive to improving the protection performance of spacecraft protective structures against space debris, reducing the occurrence of spacecraft disintegration events and spacecraft collision events, and may also promote the development of many fields through the development of new technologies. Aim: Through the latest application and development of spacecraft, the advantages and disadvantages of various protection structures are summarized, and the development trend of academic and aerospace protection engineering is analyzed. Methods: Through the latest representative patent research methods for spacecraft space debris, research content, and creative structure, the principle and characteristics of the protective structure are demonstrated. Results: By comparing the application of different spacecraft space debris protection structures, the existing problems of the current protection structures are listed, and the potential development paths and research topics are put forward Conclusion: The development of aerospace, military, and other industries benefit from the development of protective structures, and the composite spacecraft space debris protection structures have broad development prospects.