An Israeli-designed vest could significantly reduce astronauts’ radiation exposure on the way to the Moon or Mars, according to a new study.
The vest, called AstroRad and built by the Israeli company StemRad, was tested aboard NASA’s Artemis I mission in late 2022. The findings show that the vest could reduce radiation exposure by as much as 60% percent during a severe solar storm.
The vest is designed to shield the organs most vulnerable to radiation damage, including bone marrow, lungs, the stomach, colon, breasts and ovaries, using a dense, hydrogen-rich plastic material arranged in a honeycomb pattern. The tested version weighed about 26 kilograms, roughly 57 pounds.
The Matroshka AstroRad Radiation Experiment (MARE) was a joint project between the German Aerospace Center, NASA, the Israel Space Agency, Israel’s Ministry of Innovation, Science and Technology and StemRad. The Tel Aviv-based firm was founded in 2011.
To test the vest, NASA sent two mannequins shaped like human torsos, nicknamed Helga and Zohar, on the uncrewed 25.5-day trip around the Moon and back aboard the Orion spacecraft. Zohar wore the AstroRad vest, while Helga did not. Both were equipped with thousands of radiation sensors to measure how much radiation reached different parts of the body.
Artemis I did not fly through an actual solar storm, so scientists used a computer model, checked against the real radiation data from the mission, to estimate how the vest would perform if astronauts were caught in severe solar storms. Modeled on a severe 1972 solar storm, the vest reduced radiation exposure by 60.7%. Modeled on a 1989 storm with more penetrating radiation, it reduced exposure by 38.5%.
Researchers estimated that the reduction could extend the period astronauts could remain below specified radiation-risk thresholds by roughly 40 to 193 additional days, depending on the scenario, although they stressed that this was a model estimate. The vest also provided about 30% more effective protection than a whole-body shielding configuration of the same weight, suggesting that targeted protection can be more efficient than distributing shielding evenly across the body.
“An experiment MARE marks an important transition from measuring the radiation environment in space to evaluating practical countermeasures that can be tested under mission conditions,” said Ran Levana, director of the Israel Space Agency.
StemRad CEO Dr. Oren Milstein called the test “a formative test for AstroRad in deep space and a significant milestone for StemRad.” He said he hopes the vest “will become an ongoing Israeli contribution to NASA’s manned space program… and help pave the way for the participation of additional Israeli astronauts in future missions.”
Israeli Minister of Innovation, Science and Technology Gila Gamliel said the study “confirm[s] the strong position of the Israeli space industry at the forefront of innovation and global science.”
Israeli teams have already submitted proposals to fly further experiments on Artemis III, NASA’s planned next Moon mission, with some clearing the agency’s initial review. Final approval depends on NASA’s assessment of readiness, safety and scheduling.
The findings were published in the peer-reviewed journal Science Advances.
