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Space Technology

Game Changing Development

Protection Against Radiation in Space Galactic and solar radiation pose risks to both astronauts and space-based assets. Galactic Cosmic Rays (GCR) represent an ever-present background radiation comprising energetic protons and heavier elements. Energetic charged particles can also come from periods of adverse solar activity, coined Solar Energetic Proton (SEP) events but, unlike GCR, are transient, randomly occurring

increases in the radiation environment. Events can last from days to weeks with frequency modulated by the roughly 11-year solar cycle and intensities spanning over 6 orders of magnitude above quiet time levels. Both sources represent risks to humans in space through direct human exposure and damage to spacebased systems.

Solar Dynamics Observatory imagery showing a large x-ray flare from Active Region AR1263. Energetic protons arrived at Earth shortly after.

Mitigation strategies for SEP events have predominantly relied on passive shielding techniques where materials such as aluminum and polymers are used to ‘absorb’ the incident radiation. However, this method leads to constraints on vehicle design and does not always ensure vehicle hardware is protected from radiation-induced failure. Particularly important is the ability to alert crews to potential events in order that preventive actions can be taken such as seeking shelter and powering down vital instrumentation. There is relatively little capability to predict when events will occur or their intensities. The Advanced Radiation Protection project is a Game Changing Program being conducted by task leaders at NASA’s Johnson Space Center with support from The University of Alabama in Huntsville and The University of Tennessee, as well as NASA’s Langley Research Center, Marshall Space Flight Center, and Goddard Space Flight Center. This project is focused on providing mission

operators with tools to assist in mission planning and design, assessment of ‘worst-case’ radiation dose, prediction of event occurrence, and projection of cumulative radiation dose once an event has begun. Tools are being built utilizing historical satellite data spanning four decades, satellite imagery of the Sun, and large-scale first-principles simulations of the inner heliospheric environment. The Game Changing Development (GCD) Program investigates ideas and approaches that could solve significant technological problems and revolutionize future space endeavors. GCD projects develop technologies through component and subsystem testing on Earth to prepare them for future use in space. GCD is part of NASA’s Space Technology Mission Directorate. For more information about GCD, please visit

SDO extreme ultraviolet imagery showing constantly changing magnetic field lines. National Aeronautics and Space Administration Langley Research Center 100 NASA Road Hampton, VA 23681-2199

NASA Facts FS-2013-08-207-LaRC

Protection Against Radiation in Space