Analysis of data from the Artemis I mission showed that the AstroRad radiation-protection vest can reduce an astronaut’s exposure to intense solar radiation by up to 60 percent. The study is based on measurements obtained during the uncrewed flight of the Orion spacecraft to the Moon. For the experiment, two anthropomorphic human-torso phantoms, Zohar and Helga, were placed inside Orion. They were designed to simulate the female body because the breasts and ovaries are particularly sensitive to ionizing radiation. Dosimeters were installed inside both phantoms, but only Zohar was equipped with the AstroRad vest.

During the Artemis I mission, no major solar proton event occurred. Therefore, the researchers used radiation data recorded by the phantoms while passing through the inner Van Allen radiation belt to estimate the potential level of protection during two major solar events in the past.

Under the scenario of the August 1972 solar event, the vest could have reduced the absorbed radiation dose by approximately 60 percent. According to the researchers’ calculations, this would have been equivalent to reducing the radiation exposure by roughly 193 days of continuous deep-space travel. For the October 1989 solar event, the protective effectiveness was estimated at approximately 40 percent, corresponding to a dose reduction equivalent to 131 days of exposure to background cosmic radiation.

Solar proton events pose a particular danger beyond Earth’s magnetosphere. Unlike relatively constant background radiation, a powerful burst of solar particles can expose astronauts to a significant radiation dose within just a few hours. Among the best-known events are the solar flares of August 1972 and October 1989.

AstroRad is a flexible protective vest made primarily from high-density polyethylene. Its design is intended to provide additional shielding for the bone marrow and organs that are particularly vulnerable to radiation exposure.

The results indicate that wearable radiation-protection systems can substantially reduce radiation doses during intense solar events. This is especially relevant for future lunar expeditions: the Artemis II mission is planned to carry a crew, while Artemis III is intended to include a human landing on the lunar surface.