The Phantom Twins are the mannequins onboard Artemis, (Zohar & Helga). Zohar will wear AstroRad, a radiation protection vest, to test how effective it could be if future crews encounter a solar storm, while Helga will be unprotected. The AstroRad vest was recently tested on the International Space Station.

The AstroRad vest is designed to protect those organs most sensitive to radiation exposure by protecting stem cell populations within them.

Watch this video. NASA Chief Highlights AstroRad Vest and International Radiation Study on Artemis I