AstroRad Vest

AstroRad Vest
What is AstroRad?
•    AstroRad is a wearable radiation-protection vest developed by StemRad and Lockheed Martin to protect astronauts from harmful radiation during deep-space missions.
•    The technology is particularly relevant to future missions to the Moon and Mars, where astronauts travel beyond the protective environment of Earth’s magnetic field.
Why is radiation a problem in deep space?
•    Earth’s magnetic field shields humans from much of the harmful space radiation, but astronauts travelling beyond this protection face increased exposure.
•    Deep-space radiation can increase the risk of cancer, radiation sickness and other health problems, particularly during intense solar particle events.
•    Completely shielding a spacecraft against radiation is difficult because additional shielding increases spacecraft mass and therefore launch requirements and costs.
How does the AstroRad vest work?
•    AstroRad uses hydrogen-rich, high-density polymers to absorb or slow down energetic radiation particles.
•    Instead of providing uniform shielding over the entire body, the vest selectively protects critical organs and tissues that are particularly vulnerable to radiation.
•    Greater protection is provided around the chest, abdomen and pelvis, which contain sensitive organs and large amounts of bone marrow.
•    Hydrogen is useful for shielding against energetic particles because hydrogen nuclei can efficiently transfer energy from incoming radiation particles through collisions.
Why is targeted shielding important?
•    The vest follows a selective-shielding approach, protecting the body's most vulnerable areas without requiring the spacecraft to carry enough material to shield the entire astronaut.
•    Its wearable design also allows astronauts to continue performing activities during a radiation event, rather than remaining inside a heavily shielded shelter throughout the event.
Testing aboard the International Space Station
•    NASA arranged for astronauts to test AstroRad aboard the International Space Station (ISS) during 2019 and 2020.
•    Astronauts wore the vest while performing normal activities and provided feedback on its comfort, mobility and functionality.
•    Testing in the ISS's microgravity environment helped engineers refine the vest for practical use during prolonged space missions.
Testing during Artemis I
•    An improved version of AstroRad was tested during NASA's Artemis I mission in 2022, which travelled around the Moon and returned to Earth.
•    The Orion spacecraft carried two human-shaped test dummies, Helga and Zohar, equipped with radiation sensors and materials designed to mimic human tissue.
•    Zohar wore the AstroRad vest, while Helga did not, allowing researchers to compare radiation exposure with and without the protective garment.
•    Research published in Science Advances in August 2026 used Artemis I radiation measurements to model the protection AstroRad could provide during historical solar storms.
•    The modelling indicated that AstroRad could have reduced effective radiation dose by about 60% during the August 1972 solar storm.
•    It could also have reduced effective radiation dose by about 40% during the October 1989 solar storm.
•    These reductions were estimated to correspond to approximately 193 fewer days and 131 fewer days of deep-space radiation exposure, respectively.
Significance for future space exploration
•    AstroRad could allow astronauts to partially continue their work during major solar particle events, reducing the need to remain sheltered for the entire duration of a storm.
•    The technology therefore represents an important approach to making long-duration human missions to the Moon and Mars safer.