Investigation of the Radiation Environment in Deep Space and Its Effect on Spacecraft Materials Properties

Not surprisingly, our knowledge of the impact of radiation on the brain has evolved considerably. Decades of work have struggled with identifying the critical cellular targets in the brain, the latency of functional change and understanding how irradiation alters the balance between excitatory and inhibitory circuits. Radiation-induced cell kill following clinical fractionation paradigms pointed to both stromal and parenchymal targets but also defined an exquisite sensitivity of neurogenic populations of newly born cells in the brain. It became more and more apparent too, that acute (days) events transpiring after exposure were poorly prognostic of the late (months-years) waves of radiation injury believed to underlie neurocognitive deficits. Much of these gaps in knowledge persisted as NASA became interested in how exposure to much different radiation types, doses and dose rates that characterize the space radiation environment might impair central nervous system functionality, with possibly negative implications for deep space travel. Now emerging evidence from researchers engaged in clinical, translational and environmental radiation sciences have begun to fill these gaps and have uncovered some surprising similarities in the response of the brain to seemingly disparate exposure scenarios. This article highlights many of the commonalities between the vastly different irradiation paradigms that distinguish clinical treatments from occupational exposures in deep space.

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Time-dependent estimates of organ dose and dose equivalent rates for human crews in deep space from the 26 October 2003 solar energetic particle event (Halloween event) using the Earth-Moon-Mars Radiation Environment Module

Space Weather ◽

10.1029/2009sw000533 ◽

2010 ◽

Vol 8 (8) ◽

pp. n/a-n/a ◽

Cited By ~ 8

Author(s):

M. PourArsalan ◽

L. W. Townsend ◽

N. A. Schwadron ◽

K. Kozarev ◽

M. A. Dayeh ◽

...

Keyword(s):

Energetic Particle ◽

Solar Energetic Particle ◽

Organ Dose ◽

Time Dependent ◽

Radiation Environment ◽

Solar Energetic Particle Event ◽

Deep Space ◽

Dose Equivalent ◽

Particle Event ◽

The Earth

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Evaluating the Martian radiation environment based on state-of-art measurements and modelling results

10.5194/epsc2020-317 ◽

2020 ◽

Author(s):

Jingnan Guo ◽

Robert Wimmer-Schweingruber ◽

Cary Zeitlin ◽

Donald Hassler ◽

Bent Ehresmann

Keyword(s):

Space Exploration ◽

Galactic Cosmic Rays ◽

Energetic Particles ◽

Solar Energetic Particles ◽

Radiation Environment ◽

Whole Body ◽

The Sun ◽

Deep Space ◽

Radiation Risks ◽

Radiation Induced

In recent years, space agencies such as ESA, NASA, the Chinese space agency and even private sectors have been planning human deep space exploration programs to the Moon and Mars. This requires a very timely and thorough investigation to better understand the space weather conditions and effects for such deep space activities in order to further develop mitigation strategies against the associated radiation risks on humans in space. Radiation damage in deep space comes mainly from two sources, Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). As an omnipresent background, radiation induced by GCRs, which are modulated by solar activities, may increase the chance of long-term health consequences, such as onset of cancer, cardiovascular diseases, skin atrophy, eye cataract, leukemia, anemia, leucopenia and malfunctions of the central nervous system. On the other hand, intense solar energetic particles (SEPs) can be considered as mightily related to deterministic radiation effects which are of great concern for space exploration. Acute radiation syndrome (ARS) or sickness or poisoning or toxicity is induced after a whole-body exposure to high doses of radiation between at the Gy [J/kg] level. Such events, despite of being rather infrequent, could result in severe damage to humans and equipment and lead to potential failure of the entire mission and therefore should be detected and mitigated as immediately as possible. Under different shielding environment, the intensity and composition of the GCRs/SEPs may vary due to the interactions of primary particles (of different energies and charges) with the surrounding material and the generation of secondaries. Therefore, a precise quantification of the change of particle spectra under different shielding environment (e.g., within a spacecraft in deep space or at Martian surface or even subsurface which might be used for future habitat shielding) using a synergistic combination of measurements and particle-transport models is essential for assessing and predicting the radiation environment therein as well as its changes during different solar activities. Another major challenge in predicting the radiation risks for humans in space is the sudden and sporadic radiation induced by SEPs which can be very intense, dynamic and may vary drastically in time and location. Specifically speaking, the radiation and particle enhancement measured at (or predicted for) Earth&#8217;s vicinity may be completely different from of that detected elsewhere in the heliosphere as for a Mars mission, due to the different magnetic connection and distance of Mars (or the cruise spacecraft) from the acceleration and release region of SEPs near the Sun. We highlight the utmost importance of utilizing multi-spacecraft in-situ and remote sensing observations of the Sun and the heliosphere to better understand such dynamic events and their dynamic effects across the heliosphere in particular at locations where human explorations may take place.

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Update on the Worsening Particle Radiation Environment Observed by CRaTER and Implications for Future Human Deep-Space Exploration

Space Weather ◽

10.1002/2017sw001803 ◽

2018 ◽

Vol 16 (3) ◽

pp. 289-303 ◽

Cited By ~ 24

Author(s):

N. A. Schwadron ◽

F. Rahmanifard ◽

J. Wilson ◽

A. P. Jordan ◽

H. E. Spence ◽

...

Keyword(s):

Space Exploration ◽

Radiation Environment ◽

Deep Space ◽

Particle Radiation ◽

Deep Space Exploration

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Galactic Cosmic Ray induced absorbed dose rate in deep space – Accounting for detector size, shape, material, as well as for the solar modulation

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2019014 ◽

2019 ◽

Vol 9 ◽

pp. A14 ◽

Cited By ~ 4

Author(s):

Saša Banjac ◽

Lars Berger ◽

Sönke Burmeister ◽

Jingnan Guo ◽

Bernd Heber ◽

...

Keyword(s):

Energy Range ◽

Dose Rate ◽

Radiation Field ◽

Absorbed Dose ◽

Cosmic Ray ◽

Radiation Environment ◽

Solar Modulation ◽

Deep Space ◽

Absorbed Dose Rate ◽

Galactic Cosmic Ray

Depending on the radiation field, the absorbed dose rate can depend significantly upon the size of the detectors or the phantom used in the models. In deep space (interplanetary medium) the radiation field is on avarage dominated by Galactic Cosmic Ray (GCR) nuclei. Here, the deep space dose rate that a typical small silicon slab detector measures is compared to a larger phantom corresponding to an ICRU sphere with a 15 cm radius composed of water. To separate and understand respective effects from the composition, size and shape differences in the detectors, this comparison is implemented in several steps. For each phantom, the absorbed dose rate due to GCR nuclei up to Z = 28, as a function of solar modulation conditions, is calculated. The main components of the GCR flux are protons, followed by helium nuclei and electrons, with Z > 2 nuclei accounting for approximately 1% of the total number of particles. Among the light nuclei with Z > 2, most abundant ones are C, N and O. In this study, we use the GEANT4 model to calculate the absorbed dose (energy deposited as ionization, divided by mass) due to the GCR flux provided by the Badhwar-O’Neill 2010 (BON-10) model. Furthermore, we investigate how the determined absorbed dose rate changes throughout the solar cycle by varying the GCR models from solar minimum to solar maximum conditions. The developed model is validated against the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) microdosimeter measurements. In our current approach, we do not consider the effects of shielding, which will always be present under realistic scenarios. A second goal of this study is to quantify the contribution of each Z = 1, …, 28 GCR nuclei to absorbed dose rate, in relation to the phantom characteristics. For each Z we determine the most relevant energy range in the GCR spectra for absorbed dose rate estimations. Furthermore, we calculate a solar modulation dependent conversion factor to convert absorbed dose rate measured in silicon to absorbed dose rate in water. This information will improve our understanding of the radiation environment due to GCR in the near-Earth deep space and also benefit further modeling efforts by limiting the number and energy range of primary particle species that have to be considered.

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Estimates of Radiation Exposures for Human Crews in Deep Space from the January 15, 2005, Solar Energetic Particle Event Using the Earth-Moon-Mars Radiation Environment Module

Nuclear Technology ◽

10.13182/nt11-a12291 ◽

2011 ◽

Vol 175 (1) ◽

pp. 202-209

Author(s):

Mahmoud PourArsalan ◽

Lawrence W. Townsend ◽

Nathan A. Schwadron ◽

Kamen Kozarev ◽

Maher A. Dayeh ◽

...

Keyword(s):

Energetic Particle ◽

Solar Energetic Particle ◽

Radiation Environment ◽

Solar Energetic Particle Event ◽

Deep Space ◽

Particle Event ◽

The Earth

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A Self-Replicating Radiation-Shield for Human Deep-Space Exploration: Radiotrophic Fungi can Attenuate Ionizing Radiation aboard the International Space Station

10.1101/2020.07.16.205534 ◽

2020 ◽

Author(s):

Graham K. Shunk ◽

Xavier R. Gomez ◽

Nils J. H. Averesch

Keyword(s):

Ionizing Radiation ◽

International Space Station ◽

Space Exploration ◽

Space Station ◽

Thick Layer ◽

Radiation Environment ◽

Radiation Shield ◽

Deep Space ◽

International Space ◽

Deep Space Exploration

AbstractThe greatest hazard for humans on deep-space exploration missions is radiation. To protect astronauts venturing out beyond Earth’s protective magnetosphere and sustain a permanent presence on Moon and/or Mars, advanced passive radiation protection is highly sought after. Due to the complex nature of space radiation, there is likely no one-size-fits-all solution to this problem, which is further aggravated by up-mass restrictions. In search of innovative radiation-shields, biotechnology holds unique advantages such as suitability for in-situ resource utilization (ISRU), self-regeneration, and adaptability. Certain fungi thrive in high-radiation environments on Earth, such as the contamination radius of the Chernobyl Nuclear Power Plant. Analogous to photosynthesis, these organisms appear to perform radiosynthesis, using pigments known as melanin to convert gamma-radiation into chemical energy. It is hypothesized that these organisms can be employed as a radiation shield to protect other lifeforms. Here, growth of Cladosporium sphaerospermum and its capability to attenuate ionizing radiation, was studied aboard the International Space Station (ISS) over a time of 30 days, as an analog to habitation on the surface of Mars. At full maturity, radiation beneath a ≈ 1.7 mm thick lawn of the melanized radiotrophic fungus (180° protection radius) was 2.17±0.35% lower as compared to the negative control. Estimations based on linear attenuation coefficients indicated that a ∼ 21 cm thick layer of this fungus could largely negate the annual dose-equivalent of the radiation environment on the surface of Mars, whereas only ∼ 9 cm would be required with an equimolar mixture of melanin and Martian regolith. Compatible with ISRU, such composites are promising as a means to increase radiation shielding while reducing overall up-mass, as is compulsory for future Mars-missions.

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