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Abstract: Upcoming space missions utilizing hyperspectral or other high-resolution sensors will generate a vast amount of data in orbit. The average communication duration between a spacecraft in low Earth orbit (LEO) to a dedicated ground station is short and in addition, due to the high amount of data to be transferred at link times, a high-performance communication system on board of the satellite is indispensable. A solution that provides longer acquisition times with the ground station is to employ a high data-rate inter-satellite link to a geostationary relay satellite, which requires a flat, compact, steerable, light-weight yet robust antenna. Such an antenna system (antenna module plus pointing module) was developed for S-Band at the Institute of Astronautics (Technische Universität München), in cooperation with German space companies, research institutes and the German Aerospace Center (DLR). Its successful operation via the geostationary relay satellite Artemis was demonstrated in cooperation with ESA in 2007. This paper describes the evaluation of an antenna system in the Ka-Band, as a successor to be developed in the next two years for high data rates and the various applications of such an antenna system. [Copyright &y& Elsevier]

Although the threat caused by an impact of near-Earth objects (NEOs) has been increasingly recognized by the international community both at a scientific and political level, no study is addressing this issue in an interdisciplinary manner. A project has been carried out at the International Space University (ISU), located in Strasbourg, France, addressing the problem of the response to a NEO threat, including space-based missions, Earth-based mitigation, political, organizational and space-law issues. This paper summarizes the main results of this study. In order to determine an appropriate response, a new system of classification of the different NEO threat scenarios was created. A specific case study was examined in the project. The threat scenario involved the NEO named 1997 XF11, with response options ranging from deflection, to destruction using the concept known as the “billiards shot”. [Copyright &y& Elsevier]