| The environment of outer space is getting deteriorative with the frequent exploration by human beings.Solar panel,which is the main power source as well as the largest exposed devices and components of the space craft,is very likely to be impacted by the hypervelocity space debris.Especially the discharge produced by the hypervelocity impact of space debris will cause serious damage to solar panels.To address this problem,we have provided support for the soft damage and protection designing of space craft solar panel on the basis of theoretical knowledge and a large number of scientific experiments.The main results are as follows:a)We have developed hypervelocity impact solar panel experiment system,Langmuir three-probe system can be used as an usual diagnostic method to detect plasma caused by hypervelocity impact.The plasma electron density and temperature increased with the increasing impact velocity at a typical angle of 30 degrees,which laid a solid foundation for the analysis of electric discharge phenomena caused by hypervelocity impact.b)The discharge produced by the hypervelocity impact on solar panel has a close relation to the impact angle,velocity and supply voltage.It seldom triggers secondary arcs at lower supply voltage.Plasma caused by hypervelocity impact and the piezoelectric effect could cause primary discharge instantly and the current peak increases with the increasing impact velocity at an angle of 30 degrees.c)Primary discharge provides an essential condition for secondary arcs.Plasma caused by hypervelocity impact on solar panel is constantly in motion and it could trigger secondary arcs when accumulated to a certain concentration after primary discharge.Secondary arcs could cause serious carbonization and ablation to the solar panel with higher current peak and longer duration than primary discharge.d)The most intuitionistic damages of solar panel caused by hypervelocity impact are perforation and debris cloud formed behind the substrate.The perforation generated during an oblique projectile impact is elliptical.The length-diameter ratio of elliptic perforation decreases with increasing impact angle and the shape of perforation is regular circular when the impact angle is 90 degrees.It is more obvious for the debris cloud to expand in long axis direction and becomes evenly distributed eventually. |
