Israeli Radiation Shielding Vest Proves Effective in Artemis 1 Lunar Mission Test

In late 2022, NASA's uncrewed Artemis 1 mission, featuring the Orion spacecraft orbiting the Moon, included a radiation protection test of the AstroRad vest developed by Israeli company StemRad. The vest is designed to shield astronauts from harmful charged particles emitted by the Sun, particularly during solar storms, which can cause acute radiation sickness and increase long-term cancer risks. The experiment was conducted in collaboration with the Israeli Space Agency and the German Aerospace Center (DLR), using two human-sized mannequins equipped with thousands of radiation sensors. One mannequin, named Zohar, wore the AstroRad vest, while the other, Helga, did not.

Although no significant solar activity occurred during the 25-day mission, researchers analyzed radiation exposure as the spacecraft passed through Earth’s Van Allen belts and extrapolated data to two major historical solar storms from 1972 and 1989. The findings, published in Science Advances nearly four years after the mission, showed that the vest reduced radiation exposure by 60% during the 1972 event and nearly 40% during the 1989 event. Protection varied by organ, with the liver, stomach, and lungs receiving over 60% less radiation, while the thyroid and esophagus had lower but still significant protection.

StemRad CEO Oren Milstein emphasized the vest’s importance for astronaut safety during solar storms, noting it allows astronauts to continue normal activities without retreating to confined radiation shelters inside the spacecraft. The vest weighs 16 kilograms, down from 26 kilograms in the original test model, while maintaining 80% of the protective capability. The vest is intended for use inside spacecraft or lunar habitats, not under spacesuits.

NASA’s evolving Artemis program plans, including the cancellation of the Lunar Gateway station in favor of a lunar base, and the pending selection between SpaceX’s Starship and Blue Origin’s Blue Moon landers for crewed lunar missions, will influence the vest’s integration. The first crewed Artemis lunar landing is planned for 2028 but may be delayed. StemRad’s collaboration with NASA under the Artemis Accords remains uncertain, but the company continues to advance the vest’s development, aiming to provide essential radiation protection for future deep space missions, including potential crewed Mars expeditions.