() –– As NASA’s Artemis II mission to send four astronauts to circumnavigate the Moon next year approaches, a new study reveals how well the Orion spacecraft will protect the crew.
The findings are based on data from Artemis I, a 25-day trip around the Moon that returned in late 2022. On that mission, the Orion capsule, which followed a trajectory similar to the one Artemis II will take, was uncrewed but carried nonhuman special guests.
Two of them, mannequin torsos called Helga and Zoharwere flown aboard as a test to see how much radiation astronauts might experience on their journey to the Moon. The dummies were made of materials that mimicked a person’s soft tissue, organs and bones, and, like the spacecraft, included detectors to track radiation exposure along the way.
Now, scientists have released the first results after studying the detector’s data, which were published this Wednesday in the journal NatureThe findings show that the shielding technology used on the spacecraft was effective in mitigating the radiation experienced during the journey.
“The Artemis I mission marks a crucial step in advancing our understanding of how space radiation affects the safety of future manned missions to the Moon,” said Sergi Vaquer Araujo, leader of the European Space Agency’s space medicine team, in a statement.
Araujo was not involved in the study, but the European Space Agency contributed five mobile dosimeters to measure radiation throughout the Orion spacecraft.
“We gained valuable insights into how space radiation interacts with spacecraft shielding, the types of radiation that penetrate to reach the human body, and which areas inside Orion offer the most protection,” Araujo said.
NASA has studied the impact of space radiation on human health for decades, dating back to the first manned space missions in the 1960s. Data is also periodically collected from astronauts who spend six months to a year aboard the International Space Station.
The station remains in low orbit, meaning it is partially protected by Earth’s magnetic field as well as by heavy shielding built into the orbital lab’s design. Earth’s magnetic field also blocks cosmic rays from reaching astronauts.
But for future deep space missions, astronauts will be far from the protection of Earth and will need to rely on heavily armored spacecraft and protective spacesuits.
Long-duration space missions to the Moon and Mars will expose astronauts to radiation from cosmic rays, or high-energy particles traveling through space. To reach outer space, astronauts will also have to pass through Earth’s Van Allen Belts, two bands of radiation that encircle our planet like giant doughnuts, according to the NASA/ESA. POT.
Sensors on the Orion capsule for the first time captured continuous radiation data during the round trip from Earth to the moon, researchers said. While there is some data from the Apollo missions, it was not collected continuously.
The sensors showed that radiation exposure inside Orion varied significantly depending on the location of the detectors, according to the study’s authors.
As Orion passed through the Van Allen Belts, data showed that the most protected areas, such as the capsule’s “storm shelter,” provided four times more protection than less protected areas. Researchers determined that radiation exposure in these locations was kept at a safe level for astronauts to avoid acute radiation sickness.
“The storm shelter is a very narrow area used to store crew supplies,” lead study author Stuart George, a scientist in the Space Radiation Analysis Group at NASA’s Johnson Space Center in Houston, said in an email. “We found that the storm shelter was the most protected area of the vehicle, which is good because it was designed that way.”
Passing through the Van Allen belts was considered comparable to the crew facing a space weather phenomenon.
As the Sun approaches solar maximum (the peak of its 11-year cycle, predicted to occur this year), it becomes more active, releasing intense solar flares and coronal mass ejections. Coronal mass ejections are large clouds of ionized gas called plasma and magnetic fields that are released from the Sun’s outer atmosphere.
When these explosions are directed towards Earth, they can affect spacecraft, satellites, the space station and even the terrestrial electrical grid.
“This helped us validate our shelter design to protect the crew from energetic solar particle events caused by space weather,” George said.
Cosmic ray exposures, which may account for the majority of radiation astronauts might experience on long-duration spaceflight, were 60% lower on Artemis I than those experienced on previous missions, including robotic missions to Mars, George said.
The team also noted a surprise in the findings. As Orion passed through the Van Allen belts, the spacecraft made a turn to activate the thruster and ensure it was on the right trajectory. During the turn, radiation levels inside the capsule dropped by 50% because the maneuver placed more of Orion’s shielding within the path of the radiation, George said.
Measurements taken during Artemis I could guide the design of future human spaceflight missions, the study’s authors said.
If a solar storm were to occur while Artemis astronauts were in space, it could last for several days.
The storm shelter concept was modified for Artemis II, as the smaller shelter aboard Artemis I might not be large enough for the crew to conduct normal operations if they had to remain there for an extended period during a solar storm, also known as a solar particle event.
“On Artemis II, the crew will strap supplies to the least protected wall of the Orion spacecraft,” George said via email.
“This means that during an energetic solar particle event, the crew will be able to use much more cabin space while still being protected from radiation. It will be really interesting to test this in space, with the crew in the loop.”
The Core stage of the powerful Artemis II rocket arrived at NASA’s Kennedy Space Center in Florida over the summer, and assembly is already underway on the Artemis III rocket, which is scheduled for launch in 2026 and aims to carry a woman and a person of color to the lunar south pole for the first time.
Meanwhile, the Artemis II crew, which includes NASA astronauts Reid Wiseman, Victor Glover, Christina Koch and Canadian Space Agency astronaut Jeremy Hansen, has training in IcelandAlthough they won’t land on the Moon, the crew will travel 7,402 kilometers beyond the far side of the Moon to capture images of surface features, such as craters, from orbit.
“(The fact that) humans are holding the camera during a lunar flyby and describing what they see in language scientists can understand is a boon for science,” said Kelsey Young, lunar science lead for Artemis II and science officer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement.
“That’s largely what we tell astronauts to do when we take them to these Moon-like environments on Earth.”
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