The AstroRad radiation vest was developed to protect astronauts traveling to the Moon or Mars, where protection must be provided to limit radiation sickness and cancer. AstroRad, which selectively shields the most sensitive organs, is currently undergoing ergonomic testing by NASA crew on ISS, in a study sponsored by the Israel Space Agency. Israeli astronaut Eytan Stibbe will join them in wearing AstroRad in microgravity for variable durations during routine activities, assessing range of motion, comfort, and general user experience of the AstroRad vest. Stibbe will provide critical feedback, making sure AstroRad is ready for crewed deep space missions.