Plastics to the rescue? A space radiation vest tested

This is new to me - they are evaluating wearable radiation protection for future astronauts:

With preparations underway for extended-duration crewed deep space missions, the health risks of solar particle events (SPEs) to astronauts are becoming increasingly pertinent. To address this hazard, the AstroRad vest, a personal radiation shielding garment providing targeted organ protection, was tested during Artemis I. Two anthropomorphic female phantoms, equipped with internal and external passive and active dosimeters, were flown aboard the Orion spacecraft: one unshielded and the other wearing AstroRad. Inner Van Allen belt transit active dosimeter measurements were extrapolated to simulate SPE scenarios, predicting effective dose reductions of ∼60% for an August 1972–like SPE and nearly 40% for an October 1989–like SPE, varying slightly with anatomical model. Such reductions could spare astronauts the equivalent of up to 193 and 131 days of deep space radiation exposure, respectively. These findings demonstrate that wearable shielding such as AstroRad could serve as a vital element for safe and sustainable human deep space exploration. 

Further down the article:

While coating an entire spacecraft hull with a meaningful thickness of radiation shielding remains impractical due to mass constraints (7), concentrating an equivalent thickness of shielding around astronauts’ most radiation-sensitive organs and tissues in the form of a vest incurs a significantly lower mass penalty. Therefore, while the use of shielding materials such as high-density polyethylene (HDPE) has been extensively explored as environmental radiation protection in space (8–11), StemRad and Lockheed Martin worked to create a low-mass emergency countermeasure solution in the form of a personal radiation shielding garment, termed the “AstroRad vest,” intended to be worn by astronauts during SPEs in deep space, reducing both the risk of radiation-induced cancer and the already low probability of acute radiation syndrome (ARS). The AstroRad vest further minimizes the mass of radiation shielding through a targeted shielding architecture of a spatially variable thickness that is inversely related to the degree of self-shielding provided by the underlying tissue at each point, a technique first developed for personal wearable gamma radiation shielding on Earth (12).  ......

 In accordance with the 2007 Recommendations of the International Commission on Radiological Protection (ICRP), the vest optimizes protection for the red bone marrow (RBM), colon, lungs, stomach, breasts, and ovaries (Fig. 2A) (38). The shielding core of the MARE AstroRad vest is composed of HDPE, which has the largest percent composition by mass of hydrogen atoms of any nonvolatile and nontoxic material, maximizing the shielding efficacy against space radiation per unit mass as determined by the Bethe radiation stopping formula (39). Because HDPE is solid and inflexible, the shielding core consists of thousands of tessellated interconnected hexagonal rods, which behave in a scale-like manner to maximize flexibility, freedom of movement, and comfort (Fig. 2B). This design resulted in a vest with a mass of ∼26 kg.