The objective of the activity is to design, manufacture and test a novel radiation shielding solution with significant improvement of the shielding efficiency per unit mass in comparison to aluminium for geostationary Earth orbit applications. Targeted Improvements: 30 - 50% increase in radiation shielding efficiency per unit mass compared to aluminium. Description: The radiation environment of the geostationary Earth orbit (GEO) is challenging for electronic components and equipment on-board the satellite. The established solution for protecting against the harmful effects of radiation is to implement heavy and high volume radiation shielding at component or equipment level. This has a significant impact on the mass and mechanical design. Alternative novel shielding solutions areunder investigation, such as using multi-layered materials that have shown significant advantages compared to current aluminium solutions. Potentially, these techniques could offer significant mass and volume savings. Additionally, if these solutions were available, more widespread use of terrestrial commercial-off-the-shelf components would be possible for space applications. The aim of this activity is to achieve a 30 - 50% increase in radiation shielding efficiency per unit mass as compared to aluminium. In addition, the activity shall also analyse how new shielding solutions could improve performance by enabling the use of low- or non-rad hard components in GEO. Lightweight radiation shielding materials suitable for the GEO environment shall be proposed and a trade-off performed. Samples will be manufactured and tested in a representative radiation environment to assess their effectiveness. Based on this, designs will be developed for component and equipment level shielding. Modular design solutions shall be considered. This will enable the shielding to be built up around varying geometries, reducing the need to customise the shielding for each application. The radiation efficiency of the shielding solution(s) shall be demonstrated on commercial-off-the-shelf test components. The deliverables of this activity will be breadboard models of both component and equipment level shielding solutions.