Scientists have gained critical insights into the dangers of radiation exposure for astronauts traveling beyond Earth’s magnetic field, thanks to data collected during NASA’s Artemis I mission. This 25-day uncrewed flight of the Orion spacecraft around the moon and back in 2022 featured two special passengers: Helga and Zohar, mannequins equipped with sensors to measure radiation exposure.
These mannequins, or “radiation phantoms,” were designed to mimic human female bodies, as women generally have a higher sensitivity to radiation than men. The phantoms were packed with sensors to track radiation levels across various organs and tissues. Zohar wore a special protective vest, while Helga had no protection, allowing researchers to compare radiation exposure with and without shielding.
During the mission, the mannequins provided continuous data using sophisticated instruments such as NASA’s HERA and the European Space Agency’s EAD sensors. This information is invaluable, as radiation exposure is one of the biggest challenges for long-term space missions beyond low-Earth orbit, such as those planned for the moon and Mars.
The Artemis program, aiming to return astronauts to the lunar surface this decade, is seen as a stepping stone for future human exploration of Mars. However, cosmic rays and solar particles pose significant risks, including radiation sickness, increased cancer risk, and potential harm to the central nervous system. The data collected during Artemis I is crucial for developing better radiation shielding and safety protocols for astronauts on such missions.
One of the key findings was that Orion’s design, particularly areas intended as “storm shelters” for space weather events, provided up to four times more radiation protection compared to other parts of the spacecraft. This finding validates the design and will be essential for safeguarding astronauts during future missions.
The study also found that the spacecraft’s orientation significantly influenced radiation exposure. When Orion performed a 90-degree turn while passing through the inner Van Allen belt, radiation levels inside dropped by half. This occurred because the spacecraft’s shielding was better aligned to block directional radiation from the belt.
Compared to previous interplanetary missions, the radiation exposure inside Orion was about 60% lower, thanks to its enhanced shielding. This is a promising indicator for the safety of astronauts on future missions that will venture even farther from Earth.
Thomas Berger, lead author of the study and radiation physicist at the German Aerospace Center, noted that final data analysis is ongoing, with complete results expected soon. These findings will help refine protective measures for long-term missions, ensuring safer journeys for astronauts exploring deep space and beyond.
Overall, the Artemis I mission has provided valuable data that will inform the design of future spacecraft and protective gear, paving the way for safe and successful human exploration of the moon and Mars.
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