Hypervelocity Debris Research Articles

Metal and Nonmetal Protective Screens for Hypervelocity Debris Shielding

The protective properties of metallic and nonmetallic screens were experimentally investigated when penetrated by an aluminum shaped charge jet at collision velocities of 7–10 km/s. Such a projectile is an analog of an elongated fragment of man-made debris. For materials of protective screens, we used glass, B4C ceramics, and diamond-silicon carbide ceramic composite. The obtained results were compared with the data obtained for metal screens. In this paper, we show that the effectiveness of screen protection increases due to phase and structural transitions that occur during the interaction of elongated hypervelocity projectile with protective screens.

Variational Bayesian multi-sparse component extraction for damage reconstruction of space debris hypervelocity impact

Variational Bayesian multi-sparse component extraction for damage reconstruction of space debris hypervelocity impact

MIMO SBR via Code Division Multiplexing for Track While Simultaneous Search

This article outlines the archetype of a novel SpaceBorne Radar (SBR) in the Ka-band for space situational awareness (SSA) based on a code-division multiplexing (CDM) multiple-input–multiple-output (MIMO) payload transceiver. Considering small-size hypervelocity debris, the functional architecture of the fully polarimetric SBR is described, including key comparisons with previous works based on single-input–multiple-output (SIMO) configurations. SBR operations are clarified via timing hierarchies in surveillance mode, the complex data hypercube structure, and the low pulse repetition frequency (L-PRF) range and range rate search (RRRS) entailing a track while simultaneous search (TWSS) contacts collection strategy. Ancillary details on the SBR functional architecture provide paramount insights to ponder critical MIMO aspects and pave the way for key research and development efforts. Finally, numerical results provide a proof of concept for the signal processor upstream the constant false alarm rate-like (CFAR-like) detection block.

Infrared Detection Method for Hypervelocity Impact Based on Thermal Image Fusion

As the number of space debris has increased rapidly in recent years, it poses a major threat to the safety of spacecraft in space, and damage assessment for space debris hypervelocity impact is very important. In order to more comprehensively and accurately describe the damage defects in the infrared inspection data collected by infrared thermal imaging technology, this paper proposes an ultra-high-speed impact damage detection algorithm based on infrared reconstruction image fusion. The algorithm first preprocesses the obtained infrared thermal response image sequence and separates the damage features, and then applies a multi-objective evolutionary optimization algorithm to extract the typical transient thermal response, and then reconstructs the feature infrared images. Finally, image fusion based on guided filtering is performed on the damage reconstruction infrared images. In this paper, several reconstruction images that represent different types of impact damage defect are merged together to improve the detection ability of the algorithm. Infrared detection experiments on damaged specimens obtained from actual hypervelocity impacts verify the effectiveness of the proposed algorithm.

Spaceborne Radar Sensor Architecture for Debris Detection and Tracking

This article delves into a novel spaceborne radar payload transceiver for augmenting space-based monitoring capabilities for near-Earth space situational awareness. The sensor complex data hypercube structure and sensor timing hierarchies in surveillance mode are addressed along with a suitable low pulse repetition frequency range and range-rate search with a pause while scan collection strategy. A bespoke active electronically scanned array-based Pulse Doppler Radar sensor in the Ka-band is then defined in order to cope with the significant Doppler stress characterizing a burst of echoes from hypervelocity debris targets. Before feeding the onboard Bayesian tracker, the complex data hypercube is processed by means of a Doppler filter bank including pulse compression in cascade with a constant false alarm rate-like block.

Nonlinear ultrasonic evaluation of disorderedly clustered pitting damage using an in situ sensor network

Pervasive but insidious, pitting damage—from pitting corrosion in maritime structures through electrical pitting in bearings to debris cloud–induced pitting craters in spacecraft—is a typical modality of material degradation and lesion in engineering assets in harsh service environment. Pitting damage may feature hundreds of clustered, localized craters, cracks, and diverse microscopic defects (e.g. dislocation, micro-voids, and cracks) disorderedly scattered over a wide area. Targeting accurate, holistic evaluation of pitting damage (mainly the existence, location, and size of the pitted area), an insight into the generation of nonlinear features in guided ultrasonic waves (i.e. high-order harmonics) that are triggered by pitting damage, is achieved using a semi-analytical finite element approach, based on which a monotonic correlation between the nonlinear ultrasonic features and the holistic severity of pitting damage is established. With such correlation, a structural health monitoring framework is developed, in conjunction with the use of an in situ sensor network comprising miniaturized piezoelectric wafers, to characterize pitting damage accurately and monitor material deterioration progress continuously. The framework is experimentally validated, in which highly complex pitting damage in a space structure, engendered by a hypervelocity debris cloud, is evaluated precisely.

Hydrodynamic Ram Effect Caused by Debris Hypervelocity Impact on Satellite Tank

To study the hydrodynamic ram effect caused by the debris hypervelocity impact on the satellite tank, a numerical simulation of the spherical debris impacting the satellite tank at the velocity of 7000 m/s was carried out based on ANSYS/LS-DYNA software. The attenuation law of debris velocity, the propagation process of the shock wave and the deformation of the tank walls were investigated. The influences of the liquid-filling ratio, the magnitude, and direction of angular velocity on the hydrodynamic ram effect were analyzed. Results show that the debris velocity decreased rapidly and the residual velocity was 263 m/s when the debris passed through the tank. The shock wave was hemispherical, and the pressure of shock wave was the smallest at the element with an angle of 90° to the impact line. The maximum diameter of the front perforation was larger than that of the back perforation and the bulge height on the front wall was smaller than that on the back wall. With the decrease of the liquid-filling ratio, the diameter of the perforations and bulge height decreased. When the debris impacted the satellite tank with the angular velocity in the x direction, the debris trajectory did not deflect. When the debris impacted the satellite tank with the angular velocities in the y and z direction, the debris trajectory deflected to the negative direction of the z axis and y axis, respectively. The magnitude of the angular velocity affects the residual velocity of debris and the diameter of perforations.

Shock Initiation of a Satellite Tank under Debris Hypervelocity Impact

For the risk assessment of a satellite to determine whether the satellite tank explodes under the hypervelocity impact, the Walker–Wasley criterion is selected to predict the shock initiation of the satellite tank. Then, the minimum power density of liquid hydrazine is determined based on the tests, the expressions of shock wave pressure and pressure duration are constructed based on the one-dimensional wave theory, and the initiation criterion for the liquid hydrazine tank is established. Finally, numerical simulation and the initiation criterion are adopted to calculate the power density in the satellite tank under the debris impact at the velocity of 10 km/s. The calculated power density agrees well with the simulated power density, they are both larger than the minimum power density, demonstrating that the shock wave generated by the hypervelocity impact is sufficient to trigger an explosion in the satellite tank.

Hypervelocity impact performance of aluminum egg-box panel enhanced Whipple shield

The enhanced Whipple shield is widely used on the space stations against space debris hypervelocity impact. Numerical investigation is conducted in this paper to test the concept of using the egg-box panel as the enhanced layer. Taking the flat panel as the benchmark and then the enhanced flat panel is substituted with the egg-box panel. For objective comparison all the egg-box panels have the same areal density as the benchmark flat panel. The performance is tested from the aspects of impact area, cell size and the axial offset, etc. The egg-box panel absorbs more incoming debris energy and generates less large fragments from itself. It can be fabricated by the stamping and forming of the aluminum flat sheet, the cost of manufacture would not be significantly increased. The egg-box panel has better performance than the flat panel and is appropriate to be the enhanced layer of the Whipple shield.

Experimental Study on the Behavior of a New Multilayer Shield against Hypervelocity Debris Impact

To protect the spacecraft from hypervelocity impact of the space debris, a new kind of multilayer shield laminated of aluminum layers and CFRP layers was designed and investigated. Three different shields with the same area density were manufactured, including single aluminum alloy layer, single CFRP layer, and multilayer of aluminum/CFRP. The hypervelocity impact experiment was carried, in which the hypervelocity projectile was launched by a two-stage light gas gun. To compare the hypervelocity impact behavior and evaluate the protection ability of the different shields, the area and depth of the projectile pits were analyzed. The experiments results show that the protection effect of the multilayer shield laminated of aluminum/CFRP layers is better than the single aluminum layer or the single CFRP layer, though they are in the same area density.

Tensile stress effect on the macromolecular orientation and erosion mechanism of an atomic oxygen irradiated polyimide

Polyimides (PIs), used in satellites, are exposed to atomic oxygen (AO) irradiation and subjected to hypervelocity debris impacts which form residual tensile stresses and accelerated erosion.The objectives of this work are to study the PI's macromolecular structure and its deformation and erosion mechanisms when subjected to tensile stresses in an AO environment.The study shows that commercial PI is anisotropic, characterized by two main axis which are related to its semicrystalline structure. Under combined effects of stress and AO irradiation the PI's morphology was dependent on the direction of the applied stress and its magnitude. When the stress was applied parallel to the first main axis a carpet-like texture was formed. When the stress was however applied parallel to the second main axis an ordered surface was formed orthogonal to the direction of the applied stress.A mechanism which relates these findings to the PI macromolecular orientation is suggested.

Debris/Micrometeoroid Impacts and Synergistic Effects on Spacecraft Materials

AbstractIn the last 40 years, the increased space activity created a new form of space environment of hypervelocity objects—space debris—that have no functional use. The space debris, together with naturally occurring ultrahigh velocity meteoroids, presents a significant hazard to spacecraft. Collision with space debris or meteoroids might result in disfunction of external units such as solar cells, affecting materials properties, contaminating optical devices, or destroying satellites. The collision normally results in the formation of additional debris, increasing the hazard for future missions. The hypervelocity debris effect is studied by retrieving materials from space or by using ground simulation facilities. Simulation facilities, which include the light gas gun and Laser Driven Flyer methods, are used for studying the materials degradation due to debris impact. The impact effect could be accelerated when occurring simultaneously with other space environment components, such as atomic oxygen, ultraviolet, or x-ray radiation. Understanding the degradation mechanism might help in developing materials that will withstand the increasing hazard from the space debris, allowing for longer space missions. The large increase in space debris population and the associated risk to space activity requires significant measures to mitigate this hazard. Most current efforts are being devoted to prevention of collisions by keeping track of the larger debris and avoiding formation of new debris.

RETRACTED: The laser-driven flyer system for space debris hypervelocity impact simulations

This article has been retracted at the request of the Editors and Author. Please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). Reason: The authors have plagiarized part of a paper that had already appeared in Acta Mater. , 52 (2004) 5539–5549, doi: 10.1016/j.actamat.2004.08.013 . One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and we apologize to readers of the journal that this was not detected during the submission process.

A quantitative analysis of computed hypervelocity debris clouds

This paper presents quantitative analyses of computed hypervelocity debris clouds due to aluminum spheres, rods and disks impacting aluminum bumper plates. The computations were performed using an algorithm to convert distorted Lagrangian finite elements to meshfree particles. The analyses were performed using a new postprocessing algorithm. The combination of this computational approach and this postprocessing algorithm is also used to characterize behind-armor debris due to tungsten rods impacting steel plates at ballistic velocities, and the results are compared to test data. The quantitative analyses are an extension of previous qualitative comparisons to radiographs of hypervelocity debris clouds.

Response of composite materials to hypervelocity impact

Abstract Investigation of composite materials response to hypervelocity impact by space debris has been carried out. In order to simulate hypervelocity impact, a unique laser driven flyer plate (LDFP) system was used, generating hypervelocity debris with velocities of up to 3 km/s. The materials studied in this research were Kevlar 29/epoxy and Spectra1000/epoxy thin film micro-composites (thickness of about 100 μm). Both Spectra and Kevlar fibers are used in long-duration spacecraft outer wall shielding to reduce the perforation threat. The micro-mechanical response of different composites was studied and correlated to the fiber, the matrix and the fiber/matrix interface properties. Visual and microscopic examinations of the damaged area identified fiber debonding as the prevailing failure mechanism. On the basis of a simple energy balance model it can be stated that for Spectra/epoxy composite the dominant mechanism is new surface creation, whereas for Spectra surface-treated fibers/epoxy the fiber pull out is the dominant mechanism. For Kevlar/epoxy fiber, pull out mechanism plays an important role.

Analysis methodologies for assessing micro-meteoroids and orbital debris risk to spacecraft

Every space system is exposed to the risk of collision with space debris and micro-meteoroids throughout its orbital life. Because of the large collision velocities, debris or meteoroids in the millimetre to centimetre range may cause significant damage to a spacecraft, which can result in potential generation of debris, loss of equipment and mission failure. The current paper deals with the probabilistic risk assessment of spacecraft survivability under micro-meteoroids and orbital debris (MMOD) impact. The typical process to calculate the MMOD induced risk is summarized and the main uncertainties and limitations affecting the assessment are discussed together with a simple example of a MMOD risk assessment performed for the European spaceship automated transfer vehicle. In order to increase the level of accuracy of MMOD risk assessments, improvements are necessary in the following critical areas: failure criteria analysis, project-dedicated hypervelocity impact testing and debris environment models.

Hypervelocity impacts on thin brittle targets: Experimental data and SPH simulations

The meteoroids and debris environment play an important role in the reduction of spacecraft lifetime. Ejecta or secondary debris, are produced when a debris or a meteoroid impact a spacecraft surface. Brittle materials are particularly sensitive to HVI in term of damages and amount of ejected matter: the ejected fragments total mass is in the order of 100 times bigger than the impacting mass. The French atomic energy commission (CEA) faces the same problem in the Laser MégaJoule project. The lasers optics will be bombarded by hypervelocity debris and shrapnel resulting from target disassembly. Two millimeter thick fused silica disposable debris shields (DDS) located in front of the main debris shields might be used to reduce very small shrapnel cratering on the main debris shields. The aim of this paper is to study the damaging and ejection processes that occur during HVI on thin brittle targets. A two-stage light-gas gun has been used to impact 2 mm DDS with 500 μm steel projectiles. Experimental characterization of ejected matter has also been performed: lightweight paperboards coated with adhesive have been used to collect ejected fragments including spalls. Numerical simulation using the smooth particle hydrodynamics (SPH) method of LS-DYNA and the Johnson Holmquist material model were performed. The results of these calculations are compared to experimental data which include the damage features in the targets (spalled zones and perforation hole) and the ejection clouds. Satisfying agreement between numerical and experimental simulations was obtained for damage characteristics and ejection phenomena.

Hypervelocity impact resistance of reinforced carbon–carbon/carbon–foam thermal protection systems

Abstract Common aero vehicles (CAVs) are aerodynamically designed, (from orbit) re-entry, un-powered military vehicles planned to be used for deployment of the desired munitions with increased accuracy and range. In one of the currently considered designs of the CAVs, their outer skin is planned to be constructed from two-ply panels. The outer play is made of a carbon–carbon composite while the inner ply is constructed from a carbon-based foam. In the present work a transient non-linear-dynamics-based analysis is carried out in order to predict the extent of damage and the probability for failure of the carbon–carbon/carbon–foam CAV panels during potential hypervelocity impact of space debris with the outer surface of the CAVs. The results obtained show that the extent of damage scales with the normal component of the momentum associated with the debris particles just before the impact. In addition, it is found that despite its relatively low strength, the carbon–foam can provide a major increase in the resistance of the CAV panels towards penetration of the hypervelocity debris particles. This finding has been linked with an attendant consolidation of the foam, the process that is capable of absorbing a substantial amount of kinetic energy carried by the debris particles.

A Review of Hypervelocity Debris Testing at the Air Force Research Laboratory

In this paper, we describe a compact, low cost, fast turn-around-time technique used at the Air Force Research Laboratory to study hypervelocity debris impact effects on spacecraft structures and components. The technique described was used to study debris effects in the areas of: shock physics, debris-produced contamination, chemical analyses of the impact ejecta and debris initiated spacecraft discharge. Examples of research results obtained with the technique are presented and illustrate problems encountered in the field of space debris effects on spacecraft.

Numerical simulation of space debris impacts on the Whipple shield

The authors carried out three series of experimental tests of the first bumper perforation and main wall cratering processes directly caused by three types of projectiles with about 2, 4 and 7 km s −1 impact velocities but comparable initial kinetic energies, by using three different accelerators (one-stage powder gun, two-stage light-gas gun and rail gun), for the purpose of investigating space debris hypervelocity impacts onto single-walled Whipple bumper shields [1]. In the present study, after reviewing the numerical simulation method of hydrocode for both Eulerian and Lagrangian descriptions, a number of parametric numerical simulation analyses using multiple material Eulerian methods were performed in order to optimize the material properties of bumper and main wall materials through comparison with experimental results of single target impacts by the projectiles. In particular, the material data on the dynamic fracture phenomena are discussed in detail in the first part. Then a couple of numerical calculations using the interactive Lagrangian rezoning method to simulate the overall impact process against the single walled Whipple shield were performed and compared with the corresponding experimental results. Both results indicated fairly good agreement with each other. Moreover, it was demonstrated that the present method is helpful and efficient in understanding the impact phenomena and fracture mechanism in the space debris hypervelocity impact problem. Finally the multiple material Eulerian method was applied to the same problems modeled by the interactive Lagrangian rezoning method used previously, because the former is much easier to use for almost all users, although it is more diffusive and unclear of material boundaries than the latter. Those two kinds of numerical results also indicated fairly good agreements with each other.