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Cross-sectional area is an important parameter for spacecraft breakup debris as it is the directly measured data in space observation. It is significant for observing and analysing the spacecraft breakup event to accurately modelling the area distribution of the breakup debris. In this paper, experimental study has been performed on debris area distribution characteristics of spacecraft under hypervelocity impact. The tests are carried out at the ballistic ranges of CARDC. Aluminium projectiles are launched to normally impact the simulated spacecrafts at about 3.0 km/s. The simulated spacecrafts are made up of aluminium plates, filled with some simulated electronics boxes, each of which was installed with a circuit board. “Soft-catch” devices are used to recover the breakup fragments. The test results show that: 1) the relationship between the cross-sectional area and the characteristic length of debris, which can be obtained in the logarithmic coordinates by linear fitting, represents the debris shape characteristic in a certain extent; 2) the area-to-mass ratios of fragments show normal distributions in the logarithmic coordinates; 3) debris made of different materials can be distinguished by different peaks on the distribution curves; 4) the area-to-mass ratio distributions can be expressed by a linear superimposition of several normal functions which represent the main materials of the spacecraft. [ABSTRACT FROM AUTHOR]

Abstract Four kinds of aramid fibre and three compound modes of aramid with ceramic fibre were studied by hypervelocity impact tests respectively to probe the fabric layer with higher performance in space debris shield configuration. The aramid fibres include the Aramid-II manufactured in America, the Aramid-II, the Aramid-III and the PBO manufactured in China. Based on the above test results, the Aramid-III was chosen to compound with the basalt. The compound modes include hybrid weaving, affixing the Aramid-III and basalt fabric layers with the glue, and sewing them with the aramid thread. The configurations are impacted by the 5 mm-diameter Al projectile with the velocities of 4.5 km/s to 5.0 km/s. The test results show that the fabric layer containing Aramid-III fabric has equivalent shielding performance with the PBO fabric, and they are better than the other two stuffed layers containing Aramid-II fabric respectively under the equivalent areal density. The performance of stuffed layer is influenced by the adhesion degree of basalt and Aramid-III fibre. The three compound modes all improve the fabric adhesion degree, however, the over adhesion makes against dissipating the kinetic energy of debris cloud, which causes the performance to degrade. Highlights The influences of aramid fibre and its compound with ceramic on shielding performance are studied. The hybrid fabric is designed and woven to use as the stuffed layer. The stuffed fabric layers are tightened by the affixing glue and the sewing aramid thread. [ABSTRACT FROM AUTHOR]

In order to study the cracking and intercepting mechanism of stuffed layer configuration on the debris cloud and to develop stuffed layer configuration with better performance, the hypervelocity impact tests on shielding configurations with stuffed layer were carried out. Firstly, the hypervelocity impact tests on the shielding configuration with stuffed layer of 3 layer ceramic fibre and 3 layer aramid fibre were finished, the study results showed that the debris cloud generated by the aluminum sphere impacting bumper at the velocity of about 6.2 km/s would be racked and intercepted by the stuffed layer configuration efficiently when the ceramic fibre layers and aramid fibre layers were jointed together, however, the shielding performance would be declined when the ceramic fibre layers and aramid fibre layers were divided by some distance. The mechanism of stuffed layer racking and intercepting the debris cloud was analyzed according to the above test results. Secondly, based on the mechanism of the stuffed layer cracking and intercepint debirs cloud the hypervelocity impact tests on the following three stuffed layer structures with the equivalent areal density to the 1 mm-thick aluminum plate were also carried out to compare their performance of cracking and intercepting debris cloud. The mechanisms of stuffed layer racking and intercepting the debris cloud were validated by the test result. Thirdly, the influence of the stuffed layer position on the shielding performance was studied by the test, too. The test results would provide reference for the design of better performance shielding configuration with stuffed layer. [ABSTRACT FROM AUTHOR]

Spacecraft shields play an important role in shielding against the impact of space debris. Increasing the dispersion degree of the debris produced by the impact of the space debris on the bumper of configuration is able to lower the concentration of debris impacting on the rear plate and thus to reduce the risk of debris perforating the rear plate. In order to improve the dispersion degree, the N-shape configuration is proposed and studied by hypervelocity impact test with the velocity of 4.80 km/s and numerical simulation with the velocities ranging from 3.0 km/s to 7.0 km/s. As a comparison, the distribution of debris impacting on the rear plate is also investigated for the parallel triple-wall configuration with the same areal density. It is found that this degree is increased in the N-shape configuration due to the oblique plate, and therefore the risk of debris perforating the rear plate is reduced compared to the case of parallel triple-wall configuration. [ABSTRACT FROM AUTHOR]