Israeli Radiation Vest Shows Promise for Astronaut Protection
An Israeli-developed radiation protection vest, named AstroRad, has demonstrated significant potential in shielding astronauts from harmful solar radiation during deep space missions, according to a Ynet report on September 10. Developed by StemRad in collaboration with Lockheed Martin and the Israeli Space Agency, the vest is designed to protect astronauts from high-energy particles, primarily protons, emitted by the sun during solar flares. These events pose a major threat to long-duration space expeditions beyond Earth's magnetic field.
The concept for AstroRad originated from StemRad's earlier development of a radiation protection device for rescuers following the 2011 Fukushima nuclear disaster. This initial technology focused on protecting the pelvic region, where a significant portion of active bone marrow is located, crucial for blood cell production. The developers reasoned that concentrating protection on the most vulnerable areas, rather than uniformly covering the entire body, would be more effective given weight constraints.
AstroRad utilizes a high-density polyethylene material, a plastic rich in hydrogen, which effectively slows charged particles while generating less secondary radiation than heavier materials like lead. The vest is constructed from thousands of small hexagonal elements, arranged like scales, allowing it to flex with the wearer's body. The thickness of the protective layer varies, with more material concentrated over sensitive organs such as bone marrow, lungs, the gastrointestinal tract, and reproductive organs.
Initial tests of AstroRad occurred on the International Space Station starting in November 2019, focusing on usability, including ease of donning and doffing, mobility, and comfort during extended wear. Israeli astronaut Eytan Stibbe also tested the vest on the ISS in April 2022. A key experiment took place during NASA's uncrewed Artemis I mission in late 2022, where two female-body-form mannequins, "Zoë" (wearing AstroRad) and "Helga" (unprotected), traveled around the Moon. While the mission did not experience a major solar storm, researchers used data from the Orion spacecraft's passage through Earth's radiation belts to calculate AstroRad's effectiveness.
Calculations based on simulated solar storms from August 1972 and October 1989 suggest AstroRad could reduce effective radiation doses by approximately 60% and 40%, respectively. The difference in effectiveness is attributed to the varying composition of particle streams in different solar events. AstroRad is intended for use during solar flare warnings, worn for several hours or days, and is designed to complement existing spacecraft shielding and monitoring systems. The development is seen as a vital component for future long-duration missions, including potential journeys to Mars.
