アルテミスIの放射線測定でオリオンの安全性が証明される(Artemis I Radiation Measurements Validate Orion Safety for Astronauts)

2024-10-09 NASA

＜関連情報＞

• https://www.nasa.gov/missions/artemis/artemis-1/artemis-i-radiation-measurements-validate-orion-safety-for-astronauts/
• https://www.nature.com/articles/s41586-024-07927-7

アルテミスI月ミッションにおける宇宙放射線測定 Space radiation measurements during the Artemis I lunar mission

Stuart P. George,Ramona Gaza,Daniel Matthiä,Diego Laramore,Jussi Lehti,Thomas Campbell-Ricketts,Martin Kroupa,Nicholas Stoffle,Karel Marsalek,Bartos Przybyla,Mena Abdelmelek,Joachim Aeckerlein,Amir A. Bahadori,Janet Barzilla,Matthias Dieckmann,Michael Ecord,Ricky Egeland,Timo Eronen,Dan Fry,Bailey H. Jones,Christine E. Hellweg,Jordan Houri,Robert Hirsh,Mika Hirvonen,… Thomas Berger
Nature  Published:18 September 2024
DOI:https://doi.org/10.1038/s41586-024-07927-7

Abstract

Space radiation is a notable hazard for long-duration human spaceflight¹. Associated risks include cancer, cataracts, degenerative diseases² and tissue reactions from large, acute exposures³. Space radiation originates from diverse sources, including galactic cosmic rays⁴, trapped-particle (Van Allen) belts⁵ and solar-particle events⁶. Previous radiation data are from the International Space Station and the Space Shuttle in low-Earth orbit protected by heavy shielding and Earth’s magnetic field^7,8 and lightly shielded interplanetary robotic probes such as Mars Science Laboratory and Lunar Reconnaissance Orbiter^9,10. Limited data from the Apollo missions^11,12,13 and ground measurements with substantial caveats are also available¹⁴. Here we report radiation measurements from the heavily shielded Orion spacecraft on the uncrewed Artemis I lunar mission. At differing shielding locations inside the vehicle, a fourfold difference in dose rates was observed during proton-belt passes that are similar to large, reference solar-particle events. Interplanetary cosmic-ray dose equivalent rates in Orion were as much as 60% lower than previous observations⁹. Furthermore, a change in orientation of the spacecraft during the proton-belt transit resulted in a reduction of radiation dose rates of around 50%. These measurements validate the Orion for future crewed exploration and inform future human spaceflight mission design.