New magnetic radiation shielding to protect astronauts during deep space missions
Following the end of the Space Radiation Superconducting Shield (SR2S) project in December 2015, scientists now have the knowledge and tools required to develop magnetic shielding structures to protect astronauts from radiation exposure caused by Galactic Cosmic Rays. Long-term radiation exposure whilst in space greatly increases an astronaut’s risk of developing certain types of cancer. To evaluate the feasibility of producing such a shield, the project focused on superconductors, materials that have no electrical resistance at extremely low temperatures, to help them solve one of the biggest challenges faced by the team - the weight of the large magnet required. In deep space, the addition of an extra 1 kg to the spacecraft would result in an additional cost of $ 15 000 to the whole mission. Currently, superconductors have only been found to work whilst in extremely cold environments, not much higher than absolute zero. The temperature of deep space offers one of the only natural environments where deploying this type of technology is not only possible but actually extremely useful as well. The researchers have presented several shielding structures that could solve this challenge, particularly the achievement of the so-called ‘pumpkin structure’. This is an active shield configuration that crucially is lightweight and thus suitable for long duration deep space missions. The structure works by reducing the material crossed by incident particles, thereby avoiding the generation of secondary particles and as a result generating a more efficient shield. By adopting this design, the magnetic shield was 3 000 times stronger than the Earth’s and should be able to project a 10 metre force field that would deflect cosmic rays around the surface of the spacecraft, protecting the astronauts inside. In particular, magnesium diboride (MgB2) could be the material of choice to create the force field. Italian company Columbus Superconductors, one of the partners in the SR2S project, has used MgB2 cables and wires in a variety of ways, from medical applications to magnetic levitation systems for transportation. This has also highlighted the secondary finding that the technology could also be utilised on Earth in a number of other fields, including healthcare and power generation. It could still be many years until such technology is ready to be actively deployed for deep space manned missions but further tests of the SR2S technology will continue to be conducted in the short to mid-term. The project itself has shown the clear potential for collaboration between European researchers and industry in the pursuit of a common European Space Policy. Consequently, the promising technological results from the project have brought the notion of preparing astronauts for deep space missions that are now not possible for humans that little bit closer to reality. For further information, please see: SR2S project website
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