Innovative Radiation Shielding Technologies
Space radiation is considered one of the major health problems and thus potentially limiting factors for long-duration human spaceflight together with isolation and microgravity-induced physiological changes. Among the various health risks, carcinogenesis caused by exposure to space radiation is now generally considered the main hindrance to interplanetary travel. Current manned missions to low Earth orbits are partially protected by the Earths’ magnetosphere. Astronauts are exposed to protons, electrons and heavy ions, along with secondary radiation including neutrons and recoil nuclei that are produced by nuclear reactions in spacecraft or tissue. MeV electrons are encountered mainly in Earth orbit but can be hazardous for EVA and transfer phases of missions. Beyond Earth orbit, the main hazards are high energy protons and ions. While the energies of concern range from tens of MeV upwards, the lower energy portion, including particles from solar particle events can easily be shielded against. The remaining environment of concern is galactic cosmic rays (GCRs) - protons and ions of energies from 100 MeV upwards, and in particular particles of energy around a GeV. These particles are difficult to shield against and interact with matter to produce significant amounts of secondary radiation. The atomic number of GCRs extends from hydrogen to uranium; however, nuclei heavier than iron (Z=26) are infrequent. Ionizing radiation is a well-known carcinogen. The risks of cancer are generally established at relatively high doses (>100 mSv). Large uncertainties remain about cancer risk at lower doses and at low dose rates (below50 mSv/h). An ambitious human exploration program would thus require substantial advances in radiation shielding concepts and counter measures.
The ESA advisory board HISPAC/FTAP recommended radiation as one of the “technology challenges” for ESA together with propulsion and torpor/hibernation. An Ariadna Call for Idea was identified as the most appropriate mechanism to start implementing the recommendation regarding new and innovative scientific and technical concepts and techniques for innovative radiation shield technologies. The team together with FTAP and TEC-EES members has therefore opened a Call for Ideas. A proposal was accepted that focusses on developing an innovative wearable radiation protection system to mitigate the effects of cosmic radiation on astronauts in space exploration missions. This project was proposed by Luca Mariotti and Andrea Ottolennhi from the Department of Physics at the University of Pavia in Italy. For more information please find the study description.
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