ISO TS 22295-2021 pdf download.Space environment (natural and artificial)一Modelling of space environment impact on nanostructured materials – General principles.
Broghe wavelength. If the electron movement is limited in three directions, a nanostructure becomes a 01)-object, or a quantum dot with discrete electronic states.
Due to nanosized scale cffects, nanostrurtured materials acquire novel mechanical. thermal, electrical, magnetic and optic properties, which can surpass the properties of conventional bulk matenaIsIIl’LiK4-IlJ. Nanocompos.tes with nanoclays. nanotubes and various nanopartides as tillers are ne of the most promising materials br space applications. They may be used as light-weighted and strong structural materials as well as mulii1unctional and smart materials of general and specilic applications, e.g. thermal stabilization. radiation shielding, electrostatic charge mitigation, protection of atomic oxygen influence and space dehels impactfJ.
Therefore, the creation of polymer nanocornposltc’s with (111cr; of various shape and composition may play the pivotal role in spacecraft development and implenwntation of challenging space prufrcts. Among possible fillers, the main attention is paid to carbon nanostructures: Iullerenes. carbon nanotubes ((NT), graphene that represent particular allotropic forms of carhonlW1li. Due to superior mechanical properties, high electric and thermal conductivity of these nanostructures, one may develop various light’wc’.ghted and strong muliibunctional nanocompositrs, Of special intelest arc CNT structural analogues, boron nitride nanotubec (RNNTs), that are electrical insulators and in addition to excellent mechanical properties and high thermal stability possess high resistivity to ox1dationli.Ul.
5 Main space envIronment components and processes
5.1 General
The space environment has a significant damaging effect on many materials. induding nanostru.ctured materials. During the Flight, the spacecraft is Influenced by a set of space environment components:
electrons and high.cnergy 1cm. cokl and hot space plasma. solar electromagnetic radiation. meteoroid; and space debris, vacuum and other factorsU-li (1I. As a result of this impact, various physical and chemical processes take place in the materials and elements of the spacecraft equipment, leading to deterioration of their operational paranieters. Depending on the nature of the processes triggered by the Impact oft hr space environment, the changes In the propertics of materials and equipment elements can have diftert’nt time scales he reversible or irreversible, and present a different degree of danger for on-board systems To evaluate the potential effects of the space environment on material properties and the characteristics of spacecraft equipment, It is important to determine the combinations of the most significant factors In various areas of outer space. In this case It should be regarded as elects caused by the Impact of individual components of the space environment, and their combined eflectIW.
5.2 Space radiation
5.2.1 General
Ionizing radiations of the Earth’s radiation belts are electron and proton flows with energies from several hundred eV to several hundred McV11.1i[l. As a result of different penetrability and energy. Ionizing particles exert influence cm all material; independent of their location, both on the exterior of spacecraft (coatings, blankets) and inside it. The dominant degradation mechanism depends on type of matenal. LET, type of ray. etc Ionizing radiation breaks chemical bonds but in other cases may lead to cross-linking in polymers. These processes cause decomposition. embrittlenient, colour change and darkening, change in electrical resistivity, mechanical strength degradation, etc. Wire Insulator indicates decrease in breakdown voltage or cracks.
5.2.2 Special features of nanoctructured materials response
Existing experimental and theoretical data demonstrate that nanostructured materials response to space radiation can differ substantially From that of conventional bulk spacecraft materials1191 IaIJ. When an electron or ion with high energy interacts with a n.ino%tructure. only a small amnuot of energy of the Incident partide is Imparted to It. ISO TS 22295 pdf download.