الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Many space environmental threats cause the degradation of materials used on the exterior spacecraft surfaces. For this reason, It is important to always update and improve existing materials and create new materials with enhanced properties to be used in space
applications . The environmental threats such as ionized radiation, micrometeoroids, vacuum, thermal cycling and atomic oxygen with different intensities depend mainly on
the position of spacecraft in the outer space. The outer space can be classified into different working orbits that depend mainly on their altitudes and inclinations. A
simulation for the space environmental threats was applied to study its effect on the space segment structure equivalent to 5 years orbital lifetime in Low Earth Orbit (LEO). Low
Earth orbit (LEO) is normally at an altitude of less than 1000 km and could be as low as 160 km above the Earth. Nowadays, all the focus has been paid to study the effect of
space threats on selected nanocomposite materials. In this thesis, aluminum oxide (Al₂O₃), multi-wall carbon nanotube (MWCNT) and
reduced graphene oxide (RGO) were dispersed in an epoxy matrix to be used in space applications. The nanocomposites were manufactured by using a commercial hand layup
technique. Also, they were modified and tested for vacuum and Atomic oxygen hazards. Moreover, The manufactured nanocomposite materials were subjected to electron beam
irradiation at 100KGy dose to simulate the ionized radiation and charged particles threats for a lifetime of 5 years. All non-irradiated and irradiated nanocomposites have been tested mechanically to evaluate the irradiation effect on their strength and their ductility. The non-irradiated and irradiated nanocomposites have been tested to evaluate their optical and electrical
properties. Furthermore, the thermophysical properties ( thermal diffusivity(α), thermal
effusivity (e) and thermal conductivity (k) ) have been measured for all samples using photoacoustic technique (PA). The investigated phenomena were explained by the
Fourier transform infrared (FTIR) and confirmed by Dynamic mechanical analysis (DMA).All the prescribed tests were performed in accordance to the European corporation for space standardization (ECSS) or the American standard for testing and materials (ASTM) procedures and standards.
Finally, it was confirmed that all epoxy/nanoparticle nanocomposites were accepted as space materials from the vacuum and the atomic oxygen tests. Moreover, because the mechanical, physical and thermal property of each material was different this allowed
them to be used in a variety of applicatio