As NASA gears up for Artemis II, a mission that will circle the moon with a crew of four astronauts as early as next year, a new study sheds light on the Orion spacecraft's radiation shielding capabilities. The data was collected during Artemis I's 25-day lunar voyage in late 2022, which, while uncrewed, carried two mannequin torsos, Helga and Zohar, to measure potential radiation exposure for astronauts.

These mannequins, composed of materials that emulate human soft tissue, organs, and bones, were equipped with detectors to monitor radiation throughout the journey. The recently published findings in the journal Nature indicate that Orion's shielding technology effectively reduced the radiation impact during the mission.

"The Artemis I mission marks a crucial step in advancing our understanding of how space radiation impacts the safety of future crewed missions to the Moon," said Sergi Vaquer Araujo, lead for the space medicine team at the European Space Agency, which contributed mobile dosimeters for the study.

NASA has been researching the effects of space radiation on human health for decades, with continuous data collection from astronauts aboard the International Space Station (ISS). The ISS, however, remains in low-Earth orbit, partially protected by Earth's magnetic field and its heavy shielding. Deep space missions, like those to the moon and Mars, will expose astronauts to cosmic rays and require well-shielded spacecraft.

The Orion capsule's sensors provided continuous radiation data from Earth to the moon and back, a first in space travel. The data revealed that radiation exposure within Orion varied significantly based on the detector locations. During the passage through Earth's Van Allen Belts, the most shielded areas of the capsule, like the "storm shelter," offered four times more protection than the least shielded areas, keeping radiation exposure within safe levels.

The "storm shelter," a small area designed for storing crew supplies, was found to be the most shielded part of the spacecraft. "We found that the storm shelter was the most shielded area on the vehicle, which is good because it was designed that way!" said lead study author Stuart George.

A surprising finding was a 50% drop in radiation levels inside the capsule during a flip maneuver to perform a thruster burn, as it positioned more of Orion's shielding against the radiation.

These measurements are crucial for designing future human spaceflight missions. For Artemis II, the storm shelter concept has been modified to allow the crew to use more of the cabin while still being effectively shielded from radiation during solar storms.

The Artemis program continues to make strides, with the core stage for Artemis II's rocket arriving at NASA's Kennedy Space Center and assembly for Artemis III already underway. Artemis II's crew is training in Iceland, preparing for a mission that will take them 4,600 miles beyond the far side of the moon, capturing images of lunar surface features from orbit.

The Artemis II mission will not only test the limits of human space exploration but also the ingenuity of our radiation shielding technologies, ensuring the safety and success of our journey to the moon and beyond.