Sen—The European Space Agency (ESA) is working on a two year project to research materials, including simulated Moon and Mars soil, that could be used to shield astronauts from space radiation during missions to the Moon, Mars or an asteroid.
ESA is working with the GSI particle accelerator in Germany to help with the research. The particle accelerator is capable of simulating the high-energy heavy atomic nuclei found in galactic cosmic radiation.
Alessandra Menicucci, managing the project, explains: "We are working with the only facility in Europe capable of simulating the high-energy heavy atomic nuclei found in galactic cosmic radiation – the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany.
"We assessed materials including aluminium, water, polyethylene plastic, multilayer structures and simulated Moon and Mars material – the latter on the basis these will be accessible to planetary expeditions. We have also confirmed a new type of hydrogen storage material holds particular promise."
Astronauts need protection from the space radiation, which comes from the Sun and from galactic cosmic radiation - atomic nuclei producing from dying stars.
GSI's linear accelerator UNILAC (UNIversal Linear ACcelerator). Credit: GSI
The International Space Station (ISS) orbits within Earth's magnetic field which provides a protective bubble from the bulk of solar radiation, but dedicated shielding is required once we venture beyond Earth's magnetic field, as would be the case on a deep space mission to re-visit the Moon or to land on an asteroid or the Red Planet.
Menicucci notes: "The real challenge for deep-space missions is galactic cosmic radiation, which cannot be shielded completely because of its very high energy, although the exposure level decreases with increased solar activity. Most are small protons or helium nuclei, but about 1% are larger, the size of an iron atom or more – known as ‘high-ionising high energy particles’ or HZE for short."
The research suggests thinner shields may be more effective, "the lighter a material's atomic nuclei the better protection" says Menicucci, and water and polyethylene have tested better than aluminium. Tests have also been conducted on new hydrogen-rich materials developed by UK company Cella Energy.
NASA are building the Space Launch System (SLS) rocket to life the Orion Multi-Purpose Crew Vehicle into space with the ambition of sending humans to an asteroid by 2025 and to Mars in the 2030s.