Overview of Importance of Materials in Space （材料在空间的重要性的概述）.pdf

Overview of Importance of Materials in Space Dr. C. Stavrinidis Head Mechanical Engineering Department ESA-ESTEC April 24th 2008 Materials KTN 2nd Annual General Meeting 1 Presentation content • Examples of spacecraft missions, achieved, planned and future; • The enabling role of materials for missions, general overview: – Structures – Thermal; – Propulsion; – Optics; – Power; – Equipment, Components, MEMS Mechanisms; • Conclusions April 24th 2008 Materials KTN 2nd Annual General Meeting 2 ESA establishments; April 24th 2008 Materials KTN 2nd Annual General Meeting 3 Overview of Importance of Materials in Space • Most materials used in spacecraft are not different from those in terrestrial applications (metallic, organic, polymeric, semiconductor, and insulating materials) HOWEVER! The operational environment is! – The physical and chemical environment in LEO and GEO is not benign, imposing a highly aggressive oxidation and degradation of materials; – It includes a rain of high energy particles and ionizing radiation from the Sun. This hot plasma (or solar wind) is trapped and concentrated in regions of the Earths magnetic field. – Thermal waves and gradients exist in the upper atmosphere. For example the International Space Station (ISS) will undergo about 175,000 thermal cycles from +125°C to –125°C as it moves in and out of the Earth’s shadow; – High velocity travelling meteoroids and debris particles form a constant threat to spacecraft. – Re-entry vehicles for Earth and planetary missions may encounter temperatures that exceed 1,600°C ; • Often the material application is subject to conflicting