报告题目：Dynamics of Artificial Objects subject to Atmospheric Drag and Unfortunate Situations like Hypervelocity Impacts

　　报 告 人：W. Schulz (Department of Aeronautical Engineering Universidad Nacional de Córdoba , Argentina)

　　摘    要：Nowadays, space equipments are designed to withstand the space environment and ensure their missions until the end of the expected useful life of the satellite. However, if not removed from nominal orbits at the end of activities, satellites can be very risky to other space objects for long periods of time. By several reasons, a single spacecraft can turn into a lot of small objects that are potentially dangerous for operational missions around them. Due to a natural mechanism, these space debris tend to reenter into Earth’s atmosphere in a period of time that varies according to their physical and orbital characteristics. The reentry of space objects is common and can lead to fragmentation under the effects of thermal and mechanical stresses some kilometers above the Earth’s surface. This presentation will be divided in two parts. One deals with the problem of reentering uncontrolled space debris subject to atmospheric drag. Some results of a space debris surveillance performed in Argentina for academic purposes will be presented. The goal is to forecast natural reentry objects for the following 7 days. The second part is about a recent research topic of our group related to associate risk assessment on particles hypervelocity impact on nano-satellites.

　　时    间：2015年8月19日 星期三 上午10:00

　　地    点：（北京西路2号）紫台大楼517会议室

　　联 系 人：董瑶（83332059）

欢迎大家积极参加！

　                                       　紫金山天文台学术委员会