Practicalities of dose management for Japanese astronauts staying at the International Space Station

Japanese astronauts started staying at the International Space Station (ISS) in 2009, with each stay lasting for approximately 6 months. In total, seven Japanese astronauts have stayed at the ISS eight times. As there is no law for protection against space radiation exposure of astronauts in Japan, the Japan Aerospace Exploration Agency (JAXA) created its own rules and has applied them successfully to radiation exposure management for Japanese ISS astronauts, collaborating with ISS international partners. Regarding dose management, JAXA has implemented several dose limits to protect against both the stochastic effects of radiation and dose-dependent tissue reactions. The scope of the rules includes limiting exposure during spaceflight, exposure during several types of training, and exposure from astronaut-specific medical examinations. We, therefore, are tasked with calculating the dose from all exposure types applied to the dose limits annually for each astronaut. Whenever a Japanese astronaut is at the ISS, we monitor readings of an instrument in real-time to confirm that the exposed dose is below the set limits, as the space radiation environment can fluctuate in relation to solar activity.

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Long term variations of galactic cosmic radiation on board the International Space Station, on the Moon and on the surface of Mars

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020028 ◽

2020 ◽

Cited By ~ 3

Author(s):

Thomas Berger ◽

Daniel Matthiä ◽

Sönke Burmeister ◽

Cary Zeitlin ◽

Ryan Rios ◽

...

Keyword(s):

Solar Cycle ◽

Radiation Exposure ◽

International Space Station ◽

Free Space ◽

Cosmic Radiation ◽

Space Station ◽

Low Earth Orbit ◽

Radiation Environment ◽

International Space ◽

Cycle 24

<div class="abstract"> <p> <div><div class="abstract"> <div><p>The radiation environment in free space and the related radiation exposure is seen as one of the main health detriments for future long-duration human exploration missions beyond Low Earth Orbit (LEO). The steady flux of energetic particles in the galactic cosmic radiation (GCR) produces&nbsp; a low dose-rate radiation exposure, which is heavily influenced by several factors including the solar cycle, the presence of an atmosphere, relevant magnetic fields (as on Earth) and of course by the relevant spacecraft shielding. Investigations of the GCR variations over the course of a solar cycle provide valuable data for exploration mission planning and for the determination of the radiation load received due to the GCR environment. Within the current work these investigations have been performed applying three datasets generated on board the International Space Station (ISS) with the DOSTEL instruments in the frame of the DOSIS and DOSIS-3D projects, with the CRaTER instrument in a Moon orbit and with the MSL-RAD instrument on the way to and on the surface of Mars. To derive GCR dose contributions on board the ISS two procedures have been developed separating the contributions from GCR from passing&rsquo;s through the South Atlantic Anomaly (SAA), as well as ways to extrapolate the GCR dose measured on board the ISS to free space based on various ranges of the McIlwain <em>L</em>-shell parameter. At the end we provide a dataset spanning the timeframe for GCR measurements on the ISS (2009 &ndash; 2011 &amp; 2012 &ndash; 2019), Moon (2009 &ndash; 2019) and Mars (2012 &ndash; 2019), thereby covering the time span from the deep minimum of solar cycle 23, the ascending phase and maximum of solar cycle 24, and the descending phase of cycle 24, which is ongoing at the time of this writing.</p> </div> </div></div> </p> </div>

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A massive bolometer on the international space station to measure energy deposition by the space radiation environment

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2003.11.284 ◽

2004 ◽

Vol 520 (1-3) ◽

pp. 167-170 ◽

Cited By ~ 1

Author(s):

S.T.P Boyd ◽

R.V Duncan ◽

W.A Holmes

Keyword(s):

International Space Station ◽

Energy Deposition ◽

Space Station ◽

Space Radiation ◽

Radiation Environment ◽

International Space ◽

Space Radiation Environment

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Predicting chromosome damage in astronauts participating in international space station missions

Scientific Reports ◽

10.1038/s41598-021-84242-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Alan Feiveson ◽

Kerry George ◽

Mark Shavers ◽

Maria Moreno-Villanueva ◽

Ye Zhang ◽

...

Keyword(s):

International Space Station ◽

Dose Response ◽

Ex Vivo ◽

Space Station ◽

Space Radiation ◽

Blood Samples ◽

International Space ◽

Significant Difference ◽

Subject Specific

AbstractSpace radiation consists of energetic protons and other heavier ions. During the International Space Station program, chromosome aberrations in lymphocytes of astronauts have been analyzed to estimate received biological doses of space radiation. More specifically, pre-flight blood samples were exposed ex vivo to varying doses of gamma rays, while post-flight blood samples were collected shortly and several months after landing. Here, in a study of 43 crew-missions, we investigated whether individual radiosensitivity, as determined by the ex vivo dose–response of the pre-flight chromosome aberration rate (CAR), contributes to the prediction of the post-flight CAR incurred from the radiation exposure during missions. Random-effects Poisson regression was used to estimate subject-specific radiosensitivities from the preflight dose–response data, which were in turn used to predict post-flight CAR and subject-specific relative biological effectiveness (RBEs) between space radiation and gamma radiation. Covariates age, gender were also considered. Results indicate that there is predictive value in background CAR as well as radiosensitivity determined preflight for explaining individual differences in post-flight CAR over and above that which could be explained by BFO dose alone. The in vivo RBE for space radiation was estimated to be approximately 3 relative to the ex vivo dose response to gamma irradiation. In addition, pre-flight radiosensitivity tended to be higher for individuals having a higher background CAR, suggesting that individuals with greater radiosensitivity can be more sensitive to other environmental stressors encountered in daily life. We also noted that both background CAR and radiosensitivity tend to increase with age, although both are highly variable. Finally, we observed no significant difference between the observed CAR shortly after mission and at > 6 months post-mission.

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