ANALYZING THE NATURAL TERRAIN SHIELDING EFFECT ON RADIATION EXPOSURE ON THE MARTIAN SURFACE BASED ON MSL/RAD MEASUREMENTS

Kurzfassung

Since Mars only possesses a thin atmosphere where high-energy galactic cosmic rays (GCRs) or solar energetic particles (SEPs) can propagate deep into the atmosphere and even create albedo particles in the surface, it is important to understand and assess the existing radiation environment on the surface of Mars to establish potential health hazards for future human explorers of the Red Planet. One way to shield future human explorers of Mars from the prevalent long-term exposure to GCRs and acute effects to exposure to sporadic SEP events would be to provide radiation shelters in the form of dedicated shielded environments, mainly by surrounding the space with additional mass. Since bringing additional mass to Mars would be cost- and resource-straining, it would be beneficial to make use of existing material on Mars to support such radiation shelters.Here, we present an overview of MSL/RAD measurements on Mars where we determined that the terrain surrounding the Curiosity rover provided a shielding effect from the incoming outer planetary radiation. We analyze seven locations where we found this terrain shielding effect to be prevalent, decreasing the measured radiation dose rate while the Curiosity rover was in vicinity of shielding terrain. Providing detailed analysis of the local terrain at each instance (i.e., how much of the sky view was blocked at each location), allows us to correlate the terrain shielding effect at each specific location with the measured decrease in dose rate. The presented analysis will help the community to assess the design requirements constraints for future radiation shelters on Mars.