BepiColombo is the joint mission of the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) to explore the planet mercury. The European contributions, namely the mercury transfer module (MTM) and the mercury planetary orbiter (MPO), are both powered by deployable solar arrays. Many materials and technologies are at their limit under the harsh highintensity, high-temperature (HIHT) conditions of the mission. Synergistic effects like photo fixation and photo enhanced contamination by ultra violet and vacuum ultra violet radiation (UV/VUV) on sunlit surfaces are considered to play an important role in the HIHT environment of the BepiColombo mission. A design verification test under UV/VUV conditions of sun exposed materials and technologies on component level is presented which forms part of the overall verification and qualification of the solar array design of the MTM and MPO. The test concentrates on the selfcontamination aspects and the resulting performance losses of the solar array under high intensity and elevated temperature environment representative for the photovoltaic assembly (PVA).
The main target of the EUROATOM FP7 project “Fuel Qualification Test for SCWR” is to make significant progress toward the design, analysis, and licensing of a fuel assembly cooled with supercritical water in a research reactor. The program of dedicated Work Package (WP4)-Prequalification was focused on evaluation of general corrosion resistance of three preselected austenitic stainless steels, 08Cr18Ni10Ti, AISI 347H, and AISI 316L, which should be prequalified for application as a cladding material for fuel qualification tests in supercritical water. Therefore, the experiments in support of WP4 concentrated on 2000-hr corrosion exposures in 25-MPa supercritical water (SCW) at two different temperatures 550°C and 500°C dosed with both 150 and 2000 ppb of dissolved oxygen content. Moreover, the water chemistry effect was investigated by conducting tests in 550°C SCW with 1.5 ppm of dissolved hydrogen content. At first, corrosion coupons were exposed for 600, 1400, and 2000 hrs in Joint Research Centre-Institute for Energy and Transport (JRC-IET), VTT Technical Research Centre of Finland Ltd. (VTT), and Shanghai Jiao Tong University (SJTU) autoclaves connected to the recirculation loop, allowing continual water chemistry control during the test. The following examination of exposed specimens consisted of weight-change calculations and detailed macro- and microscopic investigation of oxide layers using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX). With respect to general corrosion results, all tested steels showed sufficient corrosion resistance in SCW conditions taking into account the conditions foreseen for future fuel qualification test in the research reactor in CVR Rez. When the results of weight-change calculations were compared for all three materials, it was found that the corrosion resistance increased in the following order: 316L<347H<08Cr18Ni10Ti. Results obtained in hydrogen water chemistry (HWC) did not indicate any significant beneficial effect compared to tests in SCW with 150 or 2000 ppb dissolved oxygen content. Additional tests were dedicated to investigation of the surface-finish effect. In these exposures, polished, sand-blasted, and plane-milled surface-finish techniques were investigated. The beneficial effect of surface cold work in particular of sand-blasting was clearly demonstrated.
This article summarises the current challenges related to legal obligations and restrictions associated with the use of chemicals, directly affecting space industrial sector. It also highlights issues surrounding the obsolescence of materials and processes, which are indirectly linked to the restrictions in use, but often have a serious impact on the space industry. Methods for risk assessment and means for the mitigation of risks associated with material and process obsolescence are described in the article. The most relevant substances under restrictions are discussed in detail. Lastly, the evolution in waste management, as well as some implications of the UK withdrawal from the EU are additionally analysed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.