Space radiation measurements during the Artemis I lunar mission
Stuart George, Ramona Gaza, Daniel Matthiä, Diego Laramore, Jussi Lehti, Thomas Campbell-Ricketts, Martin Kroupa, Nicholas Stoffle, Karel Maršálek, Bartos Przybyla, Mena Abdelmelek, J. Aeckerlein, Amir A. Bahadori, Janet Barzilla, Matthias Dieckmann, Michael Ecord, Ricky Egeland, T. Eronen, D. Fry, Bailey H. Jones, Christine E. Hellweg, Jordan Houri, Robert Hirsh, Mika Hirvonen, Scott Hovland, Hesham Hussein, A. S. Johnson, Moritz Kasemann, Kerry Lee, Martin Leitgab, Catherine D. McLeod, O. Milstein, L. Pinsky, P. J. Quinn, E. Riihonen, Markus Rohde, Sergiy Rozhdestvenskyy, Jouni Saari, Aaron Schram, U. Straube, D. Tureček, Pasi Virtanen, G. Waterman, S. Wheeler, Kathryn Whitman, Michael Wirtz, Madelyn Vandewalle, C. Zeitlin, E. Semones, Thomas Berger
Abstract
Abstract Space radiation is a notable hazard for long-duration human spaceflight 1 . Associated risks include cancer, cataracts, degenerative diseases 2 and tissue reactions from large, acute exposures 3 . Space radiation originates from diverse sources, including galactic cosmic rays 4 , trapped-particle (Van Allen) belts 5 and solar-particle events 6 . 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 11–13 and ground measurements with substantial caveats are also available 14 . 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 observations 9 . 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.