One of the most important goals for the Human Research Program at NASA is to support investigation into understanding and quantifying health impacts of space radiation. Their final goal is to ensure that crew members can live and work in space, including locations beyond Low Earth Orbit, without exceeding acceptable radiation health risks. Galactic cosmic ray (GCR) and SEP exposure is one of the main health risks for long duration exploration. Quantifying the astronaut exposure from GCRs is a critical aspect of risk assessment for both ISS operations and long duration missions beyond the geomagnetic field.