Space Radiation Analysis Group (SRAG) Needs for Human Exploration

As human spaceflight missions expand from Low-Earth Orbit (LEO) to the Moon and Mars, the Space Radiation Analysis Group (SRAG) team must change their strategy for mitigating impacts of radiation exposure on the astronaut crew. Space radiation sources include the constant background exposure from Galactic Cosmic Radiation (GCR), Trapped Radiation from transits through the Van Allen Belts, and short-term increases in exposure from Solar Particle Events (SPEs). Once the vehicle travels outside LEO, it no longer employs the protection of the Earth’s geomagnetic field and therefore is subjected to the full impact of both GCR and SPEs. Using the International Space Station vehicle and the uncrewed Artemis-I mission as testbeds, SRAG has incorporated new technology to improve their approach to crew protection for the upcoming Beyond-LEO missions. The first crewed mission, Artemis-II, will use the Crew Active Dosimeter (CAD) and the Hybrid Electronic Radiation Detector (HERA) to monitor radiation exposure in real-time. Future missions, which incorporate lunar landings, will include the use of additional monitors to fully describe the environment. SRAG is also working with the vehicle provider to assess the inherent shielding available, both to improve the structure and to identify steps to temporarily configure the vehicle storage for crew protection during a transient event. The SRAG group maintains a console presence in Mission Control; preparations for the Beyond-LEO missions include transitioning SPE prediction models from research to operational use to better understand the space environment and development of a real-time dose projection tools to quantify possible impacts of an enhancement in activity. Finally, the team has been working to quantify the risk of specific end effects, including cancer, of radiation exposure on the individual crew members. SRAG has been tasked with mitigating the effects of radiation exposure in the Beyond-LEO space; incorporation of new technologies to enhance this capability are critical for success.