Fault tolerance analysis is a crucial and fundamental phase in any development process that has the aim to produce a dependable system and throughout the decades, each field of science improved its knowledge about all the possible threats that can affect a system during operation: space exploration field is one of the most active and focused on these studies. This research has been developed as part of the mission HERA by ESA, due to launch in 2024, and has the main goal of investigating what are the outcomes that can occur when SEU and SEMU faults affect several parts of a well-known system under test.