This thesis studies the radiation dose deposited on a 6U CubeSat in interplanetary orbit. The European Space Agency’s radiation data tool SPENVIS has been used to determine the proton flux in interplanetary space during a solar particle event which occurs only once every one hundred years. SPENVIS has further been applied to obtain a dose depth curve for this specific 1-in-100 years proton flux. Simultaneously, 6U simplified models of several materials are created as well as a realistic 6U CubeSat structure which represents the state-of-the-art in CubeSat industry. Using radiation simulation tool Fastrad, two simulations have been performed: ray-tracing simulation and forward Monte Carlo simulation. Ray-tracing simulation provides a sector shielding analysis of the models, giving an overview of the received radiation dose for each specific point in the models. Forward Monte Carlo gives an overview of the deposited radiation for each part of the model, which has shown especially beneficial for the state-of-the-art model, in which deposited dose has been obtained for each part in the model. This has led to a dataset that shows the radiation dose deposited at each location and in each part of the 6U CubeSat structure during a 1-in-100 years solar particle event that strikes in interplanetary space.