Study of Radiation Enviroment for Low-Earth Orbit (LEO) Spacecraft

The design of a space mission involves study of particle fluxes and their effects on spacecraft; space environment has a strong degrading effect on materials and components, so those need to be understood and mitigated against in order to ensure the success of mission. This work focuses on the study of Low Earth Orbit (LEO) radiation environment and how the particles interact with materials for a hypotethical space mission. Mission goal is Energetic Particle Atoms (ENA) detection using gas detector (MicroMeEGAS??) on board of a CubeSat. The payload will observe phenomena due to interation between magnetosphere and solar wind measuring precipitated particles. Being gas detector sensitive to several type of radiation, it is important to evaluate both its protection in terms of charged particles, that do not contribute to the signal, and the signal-to-noise ratio, because detector must be able to separate the desired signal from the background noise. So, the choice of the orbit requires some constraints as a consequence of the set scientific objective: we want to avoid areas where radiations are more intensive (South Atlantic Anomaly and polar regions) and for this reason we analyse the environment of LEO orbit with a low inclination. We investigate the major sources of natural environmental radiation analyzing trapped electrons and protons, solar particles flux and galactic cosmic ray intensity that arrive on and inside a cubesat at different altitudes of an appropriate Low Earth Orbit (LEO). The study of the orbit and the analysis of the radiation environment around the spacecraft are done by modeling with a web simulation tool, SPENVIS (SPace ENVironment Information System), instead Monte Carlo methods are used to simulate radiation fluxes, that penetrate into the CubeSat. Simulation results will be essential to proceed to evaluate the appropriate corrections in the instrument design, with appropriate shielding studies.