PSI - Issue 53

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Stefania Franchitti et al. / Procedia Structural Integrity 53 (2024) 397–406 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

Peer-review under responsibility of the scientific committee of the ESIAM23 chairpersons Keywords: Space Rider; Electron Beam Melting; Additive Layer Manufacturing; AM parts qualification

1. Introduction Additive manufacturing (AM) is a digital technology of layered fabrication by adding material where no cutting tool is required as in the case of a subtractive manufacturing process. According to Portoles et al. (2016), there is wide-ranging consensus on the potential applications of additive manufacturing (AM) technologies for manufacturing parts in the aerospace industry. The advantages of the use of AM for aerospace parts are numerous: the reduced lead time and associated cost, the ability to design and manufacture complex geometries that enable lightweighting, consolidation of multiple components and improvements in performance. They are deeply discussed in Blakey-Milner et al. (2021), Debnat et al. (2022) and Pant et al. (2020). Another important advantage is the reduced buy-to-fly ratio which is a measure of the material efficiency in terms of the amount of raw material needed for manufacturing the final part. In contrast with traditional machining methods, which have buy-to-fly ratios between 5 and 20 (Arcella and Froes, 2000), AM can achieve values close to one (Deppe and Koch, 2014). Gardi et al. (2017) highlights some AM advantages in terms of cost and cycle-time savings by switching from multi-piece built-up assembly to a single-piece manufactured by using AM processes. A critical challenge to AM applications in aerospace is the hurdle of certification requiring that regulatory bodies be confident that the AM systems are fundamentally well understood, and can be repeatably designed and inspected such that reliability and safety expectations can be satisfied. These certification requirements vary according to the criticality of the proposed AM system as being safety or mission-critical or otherwise. Practical certification requires connection with existing standards for traditional manufacturing as well as to standards emerging for AM processes. In this paper, the qualification procedure of additive manufactured components for a space application is presented. In particular, the qualified components are the attachment supports of the Body Flap Assembly (BFA) to be installed on the re-entry module of the Space Rider vehicle. Space Rider aims to provide Europe with an affordable, independent, reusable end-to-end integrated space transportation system for routine access and return from low orbit (Fedele et al., 2018). It will be launched by Vega- C from Europe’s Spaceport in Kourou and it will remain in Low Earth Orbit for about two months during which a wide spectrum of microgravity and IOD/IOV experiments will be performed. At the end of orbital phase mission, it will be de-orbited by means of updated VEGA AVUM acting as service module also during the orbital phase, it will perform a re-entry controlled through the combined use of both RCS and aerodynamic control surfaces and it will land on open fields by means of controlled parafoil descent phase as shown in the mission profile of Fig. 1. To maximize competitiveness and minimize the recurring cost of each mission, Space Rider is conceived to maximize reusability, has a limited size while maximizing payload capability, and requires minimal refurbishment allowing expensive components of the mission to be reused. In the framework of the SPACE RIDER project, CIRA is in charge of design, manufacturing and qualification of the whole Ceramic Thermal Protection System and of the Body Flap Assembly (BFA) of the re-entry module. In particular the BFA design is based on a hybrid approach: • Ceramic Matrix Composite (CMC) control surfaces • Metallic (Ti6Al4V) Attachments Considering the complexity of the parts, AM technology was proposed for the fabrication of the inner and outer flap supports.