This paper examines two examples of testing activities of sub-components of a 300kN methalox first-stage rocket engine developed by Pangea Aerospace, namely, theinjectors and the cryogenic pumps. One of the difficulties of these test campaignsis to evaluate the performances of these sub-components without using cryogenicpropellants and in conditions differing from flight conditions.Two different methods were used to replace the cryogenic propellants at extreme pressures and temperatures: the pumps were tested using water to replace both propellants, and the injectors were tested using water and nitrogen to account for the different propellant phases. The correlation, similarity methods, and bench sizing were detailed for both test campaigns, but only the injector test campaign was completed and its results were analyzed.The method to emulate cryogenic fluid behavior in a pump leads to the use of a bench controlling not only pressure and mass flow but also temperature to account for the cavitation effects. Furthermore, the bench must have the capability to pressurize the water under atmospheric pressure, leading to the use of a vacuum pump. The injector test campaign produces results that closely align with theoretical predictions. This enables the selection of the optimal single-element injector design through a quantitative assessment of the discharge coefficient and a qualitative evaluation of the spray angle and atomization. Although these studies are based on strong models, they must be compared to hotfire data and later flight data to be assessed fully, all the more so that the pump test campaign was not performed. / I denna rapport behandlas två exempel på provningsaktiviteter för delkomponenter av en methalox-driven 300 kN-klass raketmotor, utvecklad av Pangea Aerospace för användning på förstasteg. Delkomponenterna består av injektorerna samt dekryogena pumparna. En av svårigheterna med provkampanjerna är att utvärdera prestandan hos dessa delkomponenter utan att använda kryogena drivmedel och underförhållanden som skiljer sig från flygförhållandena. Två olika metoder användes för att imitera de kryogena drivmedlen vid extrema tryck och temperaturer. Först testades pumparna med vatten som en ersättning för de båda drivmedlen, och sedan testades injektorerna med både vatten och kväve för att ta hänsyn till de olika aggregations tillstånden. Korrelationen, likhetsmetoderna, samt provbänkstorleken utredes i detalj för bägge testkampanjer, men endast injektortestkampanjen slutfördes och dess resultat analyserades. Metoden för att efterlikna kryogena vätskors beteende i en pump leder till användning av en provbänk som inte bara reglerar tryck och massflöde utan även temperatur för att ta hänsyn till kavitations effekterna. Dessutom måste bänken ha kapacitet att trycksätta vattnet under atmosfärstryck, vilket leder till användning av en vakuumpump. Injektortestkampanjen ger resultat som ligger nära de teoretiska förutsägelserna. Detta gör det möjligt att välja den optimala injektordesignen genom en kvantitativ bedömning av utloppskoefficienten och en kvalitativ bedömning av vinkeln och finfördelningen av injektorstrålen. Även om dessa studier baseras på starka modeller måste de jämföras med data från brännprover och senare flygdata för att kunna bedömas fullt ut, särskilt som pumptestkampanjen inte genomfördes.

The particular study case in this thesis is the shock test performed on the LISA Pathfinder satellite conducted in a laboratory environment on a dedicated test bed: Vega Shock Test Apparatus (VESTA). This test is considered fully representative to study shock levels produced by fairing jettisoning event at Vega Launcher Vehicle, which induces high shock loads towards the satellite. In the frame of this thesis, some transient response analyses have been conducted in MSC Nastran, and a shock simulation tool for the VESTA test configuration has been developed. The simulation tool is based on Nastran Direct Transient Response Analysis solver (SOL 109), and is representative of the upper composite of Vega with the LISA Pathfinder coupled to it. Post-processing routines of transient response signals were conducted in Dynaworks which served to calculate Shock Response Spectra (SRS). The simulation tool is a model of forcing function parameters for transient analysis which adequately correlates with the shock real test data, in order to understand how the effect of shock generated by the launcher is seen in the satellite and its sub-systems. Since available computation resources are limited the parameters for analysis were optimised for computation time, file size, memory capacity,  and model complexity. The forcing function represents a release of the HSS clamp band which is responsible for fairing jettisoning, thus the parameters which were studied are mostly concerning the modelling of this event. Among many investigated, those which visibly improved SRS correlation are radial forcing function shape, implementation of axial impulse, clamp band loading geometry and refined loading scheme. Integration time step duration and analysis duration were also studied and found to improve correlation.  From each analysis, the qualifying shock environment was then derived by linear scaling in proportion of the applied preload, and considering a qualification margin of 3dB. Consecutive tracking of structural responses along shock propagation path exposed gradual changes in responses pattern and revealed an important property that a breathing mode (n = 0) at the base of a conical Adapter translates into an axial input to the spacecraft. The parametrisation itself was based on responses registered at interfaces located in near-field (where the clamp band is located and forcing function is applied) and medium-field with respect to the shock event location. Following shock propagation path, the final step was the analysis of shock responses inside the satellite located in a far-field region, which still revealed a very good correlation of results. Thus, it can be said that parametrisation process was adequate, and the developed shock simulation tool can be qualified. However, due to the nature of shock, the tool cannot fully replace VESTA laboratory test, but can support shock assessment process and preparation to such test. In the last part of the thesis, the implementation of some finite element model improvements is investigated. Majority of the panels in spacecraft interior exhibited shock over-prediction due to finite element model limitation. Equipment units modelled as lump masses rigidly attached with RBE2 elements to the panel surface are a source of such local over-predictions. Thus, some of the units were remodelled and transient responses were reinvestigated. It was found that remodelling with either solid elements, or lump mass connected to RBE3 element and reinforced by RBE2 element, can significantly improve local transient responses. This conclusion is in line with conclusions found in ECSS Shock Handbook.