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Abstract: In the field of space life sciences, the demand of an interdisciplinary and specific training of young researchers is high due to the complex interaction of medical, biological, physical, technical and other questions. The Helmholtz Space Life Sciences Research School (SpaceLife) offers an excellent interdisciplinary training for doctoral students from different fields (biology, biochemistry, biotechnology, physics, psychology, nutrition or sports sciences and related fields) and any country. SpaceLife is coordinated by the Institute of Aerospace Medicine at the German Aerospace Center (DLR) in Cologne. The German Universities in Kiel, Bonn, Aachen, Regensburg, Magdeburg and Berlin, and the German Sports University (DSHS) in Cologne are members of SpaceLife. The Universities of Erlangen-Nürnberg, Frankfurt, Hohenheim, and the Beihang University in Beijing are associated partners. In each generation, up to 25 students can participate in the three-year program. Students learn to develop integrated concepts to solve health issues in human spaceflight and in related disease patterns on Earth, and to further explore the requirements for life in extreme environments, enabling a better understanding of the ecosystem Earth and the search for life on other planets in unmanned and manned missions. The doctoral candidates are coached by two specialist supervisors from DLR and the partner university, and a mentor. All students attend lectures in different subfields of space life sciences to attain an overview of the field: radiation and gravitational biology, astrobiology and space physiology, including psychological aspects of short and long term space missions. Seminars, advanced lectures, laboratory courses and stays at labs at the partner institutions or abroad are offered as elective course and will provide in-depth knowledge of the chosen subfield or allow to appropriate innovative methods. In Journal Clubs of the participating working groups, doctoral students learn critical reading of scientific literature, first steps in peer review, scientific writing during preparation of their own publication, and writing of the thesis. The training of soft skills is offered as block course in cooperation with other Helmholtz Research Schools. The whole program encompasses 303h and is organized in semester terms. The first doctoral candidates started the program in spring 2009. [Copyright &y& Elsevier]

Abstract: The exposure of aircrew personnel to cosmic radiation has been considered as occupational exposure in the European Union since the European Council Directive 96/26/EURATOM became effective on 13th May 1996. In Germany the corresponding safety standards for aircrew are regulated by the German Radiation Protection Ordinance, which implemented the European law in 2001. The radiation exposure of the flight crew of the LUFTHANSA group is calculated by the DLR Institute of Aerospace Medicine in Cologne, applying the calculation program EPCARD in the framework of the aircrew dose determination system CALculated and Verified Aviation DOSimetry (CALVADOS). Besides the operational dose calculations, DLR performs measurements at airflight altitudes using active (e.g. TEPC, DOSTEL, etc.) and passive (Thermoluminescence detectors (TLDs), bubble detectors) radiation detectors to verify the calculation codes. Within these activities the project BOdy DOsimetry (BODO) comprised a long-term exposure of a anthropomorphic phantom to measure the skin and the depth dose distribution inside a human torso applying TLDs at aviation altitudes for the first time. The torso was flown onboard a LUFTHANSA Cargo aircraft for 3 months from mid of July to mid of October 2004. Over 800 TLDs were positioned for depth dose measurements in the head, the thorax and the abdomen of the torso. In addition dosemeter packages have been distributed on the surface of the torso to measure the skin dose as well as in the transport container and on the flight deck. [Copyright &y& Elsevier]

Human missions to Mars are planned to happen within this century. Activities associated therewith will interact with the environment of Mars in two reciprocal ways: (i) the mission needs to be protected from the natural environmental elements that can be harmful to human health, the equipment or to their operations; (ii) the specific natural environment of Mars should be protected so that it retains its value for scientific and other purposes. The following environmental elements need to be considered in order to protect humans and the equipment on the planetary surface: (i) cosmic ionizing radiation, (ii) solar particle events; (iii) solar ultraviolet radiation; (iv) reduced gravity; (v) thin atmosphere; (vi) extremes in temperatures and their fluctuations; and (vii) surface dust. In order to protect the planetary environment, the requirements for planetary protection as adopted by COSPAR for lander missions need to be revised in view of human presence on the planet. Landers carrying equipment for exobiological investigations require special consideration to reduce contamination by terrestrial microorganisms and organic matter to the greatest feasible extent. Records of human activities on the planet''s surface should be maintained in sufficient detail that future scientific experimenters can determine whether environmental modifications have resulted from explorations. [Copyright &y& Elsevier]

Abstract: We report dosimetric quantities measured by the Mars Science Laboratory Radiation Assessment Detector (RAD) on the surface of Mars during the 10–12 September 2017 solar particle event. Despite 23 g/cm2 of CO2 shielding provided by the atmosphere above RAD, dose rates rose above background galactic cosmic ray levels by factors of 2 to 3 over the course of several hours and leveled off at sustained peak rates for about 12 hr before declining over the following 36 hr. As the solar particle event flux was gradually declining, a shock front reached Mars and caused a sudden drop of about 15% in instantaneous dose rates. No solar particles followed the shock arrival, and the magnetic shielding of galactic cosmic rays by the shock reduced their intensity to levels below those seen before the start of the event. This event is the largest seen to date by RAD on Mars. [ABSTRACT FROM AUTHOR]

Abstract: The 10–12 September Solar Energetic Particle event produced the strongest increase of the radiation environment measured by the Radiation Assessment Detector on the surface of Mars since landing in August 2012. We report the details of the measurements of the energetic particle environment from Radiation Assessment Detector in Gale crater during this event. The Solar Energetic Particle event increased the low‐energy proton flux (below 100 MeV) by a factor of 30, and the higher‐energy proton flux by a factor of 4, above preevent levels. The 4He flux (below 100 MeV/nuc) rose by factors up to 10, and neutral particles by a factor of 2 above background. The increase started on 10 September around 19:50 UTC, peak‐level fluxes were reached on the morning of 11 September and prevailed for about 10 hr before decreasing toward background levels. The onset of a Forbush decrease on 13 September decreased the proton flux below preevent intensities. [ABSTRACT FROM AUTHOR]

The Mars Science Laboratory rover Curiosity, operating on the surface of Mars, is exposed to radiation fluxes from above and below. Galactic Cosmic Rays travel through the Martian atmosphere, producing a modified spectrum consisting of both primary and secondary particles at ground level. These particles produce an upward directed secondary particle spectrum as they interact with the Martian soil. Here we develop a method to distinguish the upward and downward directed particle fluxes in the Radiation Assessment Detector (RAD) instrument, verify it using data taken during the cruise to Mars, and apply it to data taken on the Martian surface. We use a combination of Geant4 and Planetocosmics modeling to find discrimination criteria for the flux directions. After developing models of the cruise phase and surface shielding conditions, we compare model‐predicted values for the ratio of upward to downward flux with those found in RAD observation data. Given the quality of available information on Mars Science Laboratory spacecraft and rover composition, we find generally reasonable agreement between our models and RAD observation data. This demonstrates the feasibility of the method developed and tested here. We additionally note that the method can also be used to extend the measurement range and capabilities of the RAD instrument to higher energies. [ABSTRACT FROM AUTHOR]

The radiation environment at the surface of Mars is mainly dominated by incoming galactic cosmic rays (GCRs) that propagate through the atmosphere, with sporadic strong contributions from solar energetic particles (SEPs). The main driver for changes in the radiation field, on time scales of years, is the solar modulation of the GCR flux. During times of higher solar activity, GCRs are more strongly attenuated, resulting in highest GCR fluxes during solar minimum and lowest fluxes at solar maximum. We report dosimetric measurements conducted with the Radiation Assessment Detector (RAD) from November 2019 to October 2020 during the recent deep solar minimum. RAD has been operating on board NASA's Curiosity rover on Mars since August 2012. We bring these measurements into context with RAD measurements from 2012 to 2013 around the (weak) maximum of Solar Cycle 24. The results show the impact of the changing solar modulation from 2012 to 2020 on the Martian surface radiation environment and have implications for future human exploration missions of Mars. We find that while the overall radiation dose rate has increased significantly by 50% between the two time frames, the biologically highly relevant dose equivalent rate shows a modest increase of 13%, yielding interesting input for the timing of such Mars missions within the solar cycle. We also report the first results of the analysis of the flux of medium-energy protons with 100–300 MeV on the Martian surface, yielding an important additional, in-situ measured data point for validating radiation transport models. • We report measurements of Mars' radiation field during the minimum of Solar Cycle 24. • Absorbed dose rates have increased by 50% since the maximum of Solar Cycle 24. • Dose equivalent rates show a modest increase of 13% in the same time frame. [ABSTRACT FROM AUTHOR]

The Radiation Assessment Detector, RAD, is one of the ten instruments that make up the science payload of the Mars Science Laboratory Curiosity rover. RAD is an energetic particle detector, capable of measuring the charged and neutral particles that make significant contributions to the radiation dose that will be received by future human explorers when they visit Mars. Prior to the launch of MSL in November 2011, RAD and its near-identical twin flight spare unit were calibrated using laboratory sources, charged particle beams, and neutron fields. The initial calibration parameters obtained in these tests were used for real-time data analysis by the instrument's onboard software. These parameters have subsequently been refined using data obtained during the cruise to Mars and during Curiosity's mission on the surface of Mars. The most critical use of calibration is in the dosimetry analysis performed onboard. Calibration is also used in onboard analysis to determine which events should be stored for telemetry to Earth. Accelerator data obtained with the flight spare unit after Curiosity was launched provide detailed information about the response of the organic and inorganic scintillators to ion beams over a wide range of charge and energy. Here we report on the methods used to determine calibration parameters, the results obtained, as well as providing an overview of the modifications to the instrument's software and configuration that have been made over the course of the mission. [ABSTRACT FROM AUTHOR]

Training young researchers in the field of space life sciences is essential to vitalize the future of spaceflight. In 2009, the DLR Institute of Aerospace Medicine established the Helmholtz Space Life Sciences Research School (SpaceLife) in cooperation with several universities, starting with 22 doctoral candidates. SpaceLife offered an intensive three-year training program for early-stage researchers from different fields (biology, biomedicine, biomedical engineering, physics, sports, nutrition, plant and space sciences). The candidates passed a multistep selection procedure with a written application, a self-presentation to a selection committee, and an interview with the prospective supervisors. The selected candidates from Germany as well as from abroad attended a curriculum taught in English. An overview of space life sciences was given in a workshop with introductory lectures on space radiation biology and dosimetry, space physiology, gravitational biology and astrobiology. The yearly Doctoral Students’ Workshops were also interdisciplinary. During the first Doctoral Students’ Workshop, every candidate presented his/her research topic including hypothesis and methods to be applied. The progress report was due after ∼1.5 years and a final report after ∼3 years. The candidates specialized in their subfield in advanced lectures, Journal Clubs, practical trainings, lab exchanges and elective courses. The students attended at least one transferable skills course per year, starting with a Research Skills Development course in the first year, a presentation and writing skills course in the second year, and a career and leadership course in the third year. The whole program encompassed 303 h and was complemented by active conference participation. In this paper, the six years’ experience with this program is summarized in order to guide other institutions in establishment of structured Ph.D. programs in this field. The curriculum including elective courses is documented. The applicants’ statistics revealed that personal contacts and the DLR website were most important the recruitment of doctoral candidates. The evaluation of the application and selection procedure revealed that prediction of thesis success based on master thesis mark or evaluation by the selection committee is difficult. SpaceLife Doctoral Students greatly contributed to the scientific output in terms of peer-reviewed publications of the Institute of Aerospace Medicine with a peak in the fourth year after start of the thesis and they continuously received awards for their scientific work. [ABSTRACT FROM AUTHOR]

The Radiation Assessment Detector (RAD), on board the Mars Science Laboratory (MSL) rover Curiosity, measures the energetic charged and neutral particles and the radiation dose rate on the surface of Mars. Although charged and neutral particle spectra have been investigated in detail, the electron and positron spectra have not been investigated yet. The reason for that is that they are difficult to separate from each other and because of the technical challenges involved in extracting energy spectra from the raw data. We use GEANT4 to model the behavior of the RAD instrument for electron/positron measurements.We compare Planetocosmics predictions for different atmospheric pressures and different modulation parameters Φ with the obtained RAD electron/positron measurements.We find that the RAD electron/positron measurements agree well with the spectra predicted by Planetocosmics. Both RAD measurements and Planetocosmics simulation show a dependence of the electron/ positron fluxes on both atmospheric pressure and solar modulation potential. [ABSTRACT FROM AUTHOR]

Solar radiation is among the most prominent stress factors organisms face during space travel and possibly on other planets. Our analysis of three different halophilic archaea, namely Halobacterium salinarum NRC-1, Halococcus morrhuae, and Halococcus hamelinensis, which were exposed to simulated solar radiation in either dried or liquid state, showed tremendous differences in tolerance and survivability. We found that Hcc. hamelinensis is not able to withstand high fluences of simulated solar radiation compared to the other tested organisms. These results can be correlated to significant differences in genomic integrity following exposure, as visualized by random amplified polymorphic DNA (RAPD)-PCR. In contrast to the other two tested strains, Hcc. hamelinensis accumulates compatible solutes such as trehalose for osmoprotection. The addition of 100 m M trehalose to the growth medium of Hcc. hamelinensis improved its survivability following exposure. Exposure of cells in liquid at different temperatures suggests that Hbt. salinarum NRC-1 is actively repairing cellular and DNA damage during exposure, whereas Hcc. morrhuae exhibits no difference in survival. For Hcc. morrhuae, the high resistance against simulated solar radiation may be explained with the formation of cell clusters. Our experiments showed that these clusters shield cells on the inside against simulated solar radiation, which results in better survival rates at higher fluences when compared to Hbt. salinarum NRC-1 and Hcc. hamelinensis. Overall, this study shows that some halophilic archaea are highly resistant to simulated solar radiation and that they are of high astrobiological significance. Key Words: Halophiles-Solar radiation-Stress resistance-Survival. Astrobiology 15, 987-997. [ABSTRACT FROM AUTHOR]

Space radiation has been monitored using the РД3-Б3 (in the following we use the Latin transcription RD3-B3) spectrometer–dosimeter on board a recent space flight of the Russian recoverable satellite “BION-M” No. 1. The instrument was mounted inside the satellite in a pressurized volume together with biological objects and samples. The RD3-B3 instrument is a battery operated version of the spare model of the R3D-B3 instrument developed and built for the ESA BIOPAN-6 facility on Foton M3 satellite launched on September 2007 ( Häder et al., 2009 ). It is a low mass, small dimension automated device that measures solar radiation in four channels and ionizing radiation in 256 channels of a Liulin-type energy deposition spectrometer ( Dachev et al., 2002 ). Cosmic ionizing radiation has been monitored and separated in 256 deposited energy spectra, which were further used for determination of the absorbed dose rate and flux. The paper summarizes the results for the Earth radiation environment at the altitude of 253–585 km. [ABSTRACT FROM AUTHOR]

Within a 1.5 year comprehensive fading experiment several batches of LiF:Mg,Ti and LiF:Mg,Cu,P thermoluminescence detectors (TLDs) were studied. The TLDs originated from two manufacturers and were processed by three laboratories using different annealing and readout conditions. The TLDs were irradiated with two radiation modalities (gamma rays and thermal neutrons) and were stored at two temperatures (−17.4 °C and +18.5 °C). The goal of the experiment was to verify the stability of TLDs in the context of their application in long-term measurements in space. The results revealed that the response of all TLDs is stable within 10% for the studied temperature range. No influence of the radiation type was found. These results indicate that for the properly oven-annealed LiF TLDs, fading is not a significant problem, even for measuring periods longer than a year. [ABSTRACT FROM AUTHOR]

Abstract: During their occupational activities in space, astronauts are exposed to ionising radiation from natural radiation sources present in this environment. They are, however, not usually classified as being occupationally exposed in the sense of the general ICRP system for radiation protection of workers applied on Earth. The exposure assessment and risk-related approach described in this report is clearly restricted to the special situation in space, and should not be applied to any other exposure situation on Earth. The report describes the terms and methods used to assess the radiation exposure of astronauts, and provides data for the assessment of organ doses. Chapter 1 describes the specific situation of astronauts in space, and the differences in the radiation fields compared with those on Earth. In Chapter 2, the radiation fields in space are described in detail, including galactic cosmic radiation, radiation from the Sun and its special solar particle events, and the radiation belts surrounding the Earth. Chapter 3 deals with the quantities used in radiological protection, describing the Publication 103 (ICRP, 2007) system of dose quantities, and subsequently presenting the special approach for applications in space; due to the strong contribution of heavy ions in the radiation field, radiation weighting is based on the radiation quality factor, Q, instead of the radiation weighting factor, w R. In Chapter 4, the methods of fluence and dose measurement in space are described, including instrumentation for fluence measurements, radiation spectrometry, and area and individual monitoring. The use of biomarkers for the assessment of mission doses is also described. The methods of determining quantities describing the radiation fields within a spacecraft are given in Chapter 5. Radiation transport calculations are the most important tool. Some physical data used in radiation transport codes are presented, and the various codes used for calculations in high-energy radiation fields in space are described. Results of calculations and measurements of radiation fields in spacecraft are given. Some data for shielding possibilities are also presented. Chapter 6 addresses methods of determining mean absorbed doses and dose equivalents in organs and tissues of the human body. Calculated conversion coefficients of fluence to mean absorbed dose in an organ or tissue are given for heavy ions up to Z =28 for energies from 10MeV/u to 100GeV/u. For the same set of ions and ion energies, mean quality factors in organs and tissues are presented using, on the one hand, the Q(L) function defined in Publication 60 (ICRP, 1991), and, on the other hand, a Q function proposed by the National Aeronautics and Space Administration. Doses in the body obtained by measurements are compared with results from calculations, and biodosimetric measurements for the assessment of mission doses are also presented. In Chapter 7, operational measures are considered for assessment of the exposure of astronauts during space missions. This includes preflight mission design, area and individual monitoring during flights in space, and dose recording. The importance of the magnitude of uncertainties in dose assessment is considered. Annex A shows conversion coefficients and mean quality factors for protons, charged pions, neutrons, alpha particles, and heavy ions(2< Z ≤28), and particle energies up to 100GeV/u. [Copyright &y& Elsevier]

Abstract: The paper presents observations of relativistic electron precipitations (REP) on the International Space Station (ISS) obtained by three Bulgarian-built instruments flown in 2001 and 2008–2010. The first data are from the Liulin-E094 instrument flown in May–August 2001 inside the US laboratory module of the ISS. Next the time profiles of the REP-generated daily fluences and the absorbed doses at the orbit of ISS during the period February 2008–August 2010 are analyzed in dependence of the daily Ap index and compared with the daily relativistic electron fluence with energies of more than 2MeV measured by the GOES. The REP in April 2010 being the second largest in GOES history (with a >2MeV electron fluence event) is specially studied. [Copyright &y& Elsevier]

The Mars Science Laboratory spacecraft, containing the Curiosity rover, was launched to Mars on 26 November 2011, and for most of the 253-day, 560-million-kilometer cruise to Mars, the Radiation Assessment Detector made detailed measurements of the energetic particle radiation environment inside the spacecraft. These data provide insights into the radiation hazards that would be associated with a human mission to Mars. We report measurements of the radiation dose, dose equivalent, and linear energy transfer spectra. The dose equivalent for even the shortest round-trip with current propulsion systems and comparable shielding is found to be 0.66 ± 0.12 sievert. [ABSTRACT FROM AUTHOR]

Abstract: Space radiation has been monitored successfully using the Radiation Risks Radiometer-Dosimeter (R3D) installed at the ESA EXPOSE-R (R3DR) facility outside of the Russian Zvezda module of the International Space Station (ISS) between March 2009 and January 2011. R3DR is a Liulin type spectrometer–dosimeter with a single Si PIN detector 2cm2 of area and 0.3mm thick. The R3DR instrument accumulated about 2 million measurements of the absorbed dose rate and flux of 10s resolution. The total external and internal shielding before the detector of R3DR device is 0.41gcm−2. The calculated stopping energy of normally incident particles to the detector is 0.78MeV for electrons and 15.8MeV for protons. After the Coronal Mass Ejection (CME) at 09:54 UTC on 3 April 2010, a shock was observed at the ACE spacecraft at 0756 UTC on 5 April, which led to a sudden impulse on Earth at 08:26 UTC. Nevertheless, while the magnetic substorms on 5 and 6 of April were moderate; the second largest in history of GOES fluence of electrons with energy >2MeV was measured. The R3DR data show a relatively small amount of relativistic electrons on 5 April. The maximum dose rate of 2323μGyday−1 was reached on 7 April; by 9 April, a dose of 6600μGy was accumulated. By the end of the period on 7 May 2010 a total dose of 11,587μGy was absorbed. Our data were compared with AE-8 MIN, CRESS and ESA-SEE1 models using SPENVIS and with similar observations on American, Japanese and Russian satellites. [Copyright &y& Elsevier]

Abstract: A scenario for an initial manned mission to Mars involves transits through the Van Allen Radiation Belts, a 30 day ‘short surface stay’ and a 400 day Cruise Phase (to/from the planet). The contribution to the total dose incurred through transiting the belts is relatively small and manageable. Estimates of the particle radiation hazard incurred during a 30 day stay on the surface (using ESA''s Mars Energetic Radiation Environment Models dMEREM and e MEREM) indicate that the dose is not expected to be particularly challenging health-wise due to the shielding effect provided by the Martian atmosphere and the body of the planet. This is in accord with estimations obtained using the Langley HZETRN code. Estimates of GCR exposure in free space during the minimum phase of Solar Cycle 23 determined using the CREME2009 model are in reasonable agreement with published results obtained using HZETRN (which they exceed by about 10%). The Cruise Phase poses a significant radiation problem due to the cumulative effects of isotropic Galactic Cosmic Radiation over 400 days. The occurrence during this period of a large Solar Energetic Particle (SEP) event, especially if it has a hard energy spectrum, could be catastrophic health wise to the crew. Such particle events are rare but they are not currently predictable. An overview of mitigating strategies currently under development to meet the radiation challenge is provided and it is shown that the health problem posed by energetic particle radiation is presently unresolved. [Copyright &y& Elsevier]

Abstract: HAMLET is an European Commission research project aiming at optimal scientific exploitation of the data produced within the space experiment MATROSHKA. During phase 1 of this experiment a human phantom equipped with several thousands of radiation detectors (mainly TLDs) was exposed outside the International Space Station for 1.5 years. Besides the measurements realized in Earth orbit, the HAMLET project includes also a ground-based program of intercomparison of detector response to high-energy ion beams. Within the paper, the relative response of main glow-curve peaks of various TLDs (mostly based on LiF) used in frame of the MATROSHKA experiment by three laboratories (DLR Cologne, ATI Vienna and IFJ Krakow) for radiation in space and several ion beams, has been compared. For LiF:Mg,Ti detectors a very good agreement between results obtained by the three laboratories was observed, both for space and accelerator-based exposures. This should be considered a remarkable result, taking into account that the studied TLDs originated from six different batches, manufactured by two producers exploiting different production techniques and were processed by three laboratories, using significantly different protocols (annealing, readout, calibration, glow-curve analysis). Another type of TL detectors, LiF:Mg,Cu,P, was found to show response to cosmic radiation lower than that of LiF:Mg,Ti by 5%–18%. [Copyright &y& Elsevier]

Abstract: Long-term analysis of data from two radiation detection instruments on the International Space Station (ISS) shows that the docking of the Space Shuttle drops down the measured dose rates in the region of the South Atlantic Anomaly (SAA) by a factor of 1.5–3. Measurements either by the R3DE detector, which is outside the ISS at the EuTEF facility on the Columbus module behind a shielding of less than 0.45gcm−2, and by the three detectors of the Liulin-5 particle telescope, which is inside the Russian PEARS module in the spherical tissue equivalent phantom behind much heavier shielding demonstrate that effect. Simultaneously the estimated averaged incident energies of the incoming protons rise up from about 30 to 45MeV. The effect is explained by the additional shielding against the SAA 30–150MeV protons, provided by the 78 tons Shuttle to the instruments inside and outside of the ISS. An additional reason is the ISS attitude change (performed for the Shuttle docking) leading to decreasing of dose rates in two of Liulin-5 detectors because of the East–West proton fluxes asymmetry in SAA. The Galactic Cosmic Rays dose rates are practically not affected. [Copyright &y& Elsevier]

Abstract: In 2007, the European Space Agency (ESA) initiated the development of European Crew Personal Active Dosimeters. The hardware development objective is to produce an active personal dosimeter which shows absorbed dose and dose equivalent spectra similar to a Tissue Equivalent Proportional Counter (TEPC), but which is based on more robust silicon detector devices. Several detector/dosimeter components have been investigated – by computer simulations – for their performance in the radiation field at the ISS position. [ABSTRACT FROM AUTHOR]

Abstract: The radiation environment in space is very different from the one encountered on Earth. In addition to the sparsely ionizing radiation, there are particles of different Z with energies ranging from keV up to hundreds of GeV which can cause severe damage to both electronics and humans. It is therefore important to understand the interactions of these highly ionizing particles with different materials such as the hull of space vehicles, human organs and electronics. We have used the Particle and Heavy-Ion Transport code System (PHITS), which is a three-dimensional Monte Carlo code able to calculate interactions and transport of particles and heavy ions with energies up to 100GeV/nucleon in most matter. PHITS is developed and maintained by a collaboration between RIST (Research Organization for Information Science & Technology), JAEA (Japan Atomic Energy Agency), KEK (High Energy Accelerator Research Organization), Japan and Chalmers University of Technology, Sweden. For the purpose of examining the applicability of PHITS to the shielding design we have simulated the ESA facility Matroshka (MTR) designed and lead by the German Aerospace Center (DLR). Preliminary results are presented and discussed in this paper. [ABSTRACT FROM AUTHOR]

Abstract: The radiation field in low Earth orbit (LEO) and deep space is complicated. The radiation impact on astronauts depends strongly on the particles’ linear energy transfer (LET) and is dominated by high LET radiation. Radiation risk is a key concern for human space flight and can be estimated with radiation LET spectra measured for the different organs of an astronaut phantom. At present the best passive personal dosimeters used for astronauts are thermoluminescence dosimeters (TLDs) and optically stimulated luminescence dosimeters (OSLDs) for low LET and CR-39 plastic nuclear track detectors (PNTDs) for high LET. CR-39 PNTDs, TLDs and OSLDs were used for the MATROSHKA-1 experiment to measure radiation experienced by astronauts outside the international space station (ISS). LET spectra and radiation field quantities (differential and integral fluence, absorbed dose and dose equivalent) were measured for the different organs and skin locations of the MAROSHKA phantom using CR-39 PNTDs and TLDs. The spectra and results can be used to determine the radiation quantities for astronaut''s extra vehicular activity (EVA) and for the further in-depth study of the radiation risk for astronauts. Sensitivity fading of CR-39 detectors was observed for the MATROSHKA experiment and a practical method was developed to correct it. This paper presents the radiation LET spectra measured with CR-39 PNTDs and the total radiation quantities combined from results measured with CR-39 PNTDs and TLDs. [Copyright &y& Elsevier]

Abstract: The “Pille-MKS” thermoluminescent (TL) dosimeter system developed by the KFKI Atomic Energy Research Institute (KFKI AEKI) and BL-Electronics, consisting of 10 :Dy bulb dosimeters and a compact reader, has been continuously operating on board the International Space Station (ISS) since October 2003. The dosimeter system is utilized for routine and extravehicular activity (EVA) individual dosimetry of astronauts/cosmonauts as part of the service system as well as for on board experiments, and is operated by the Institute for Biomedical Problems (IBMP). The system is unique in that it regularly provides accurate dose data right on board the space station, a feature that became increasingly important during the suspension of the Space Shuttle flights. Seven dosimeters are located at different places of the Russian segment of the ISS and are read out once a month. Two of these dosimeters are dedicated to EVAs and one is kept in the reader and will be read out automatically every 90min. During coronal mass ejections impacting Earth some of the dosimeters serve for individual monitoring of the astronauts with readouts once or twice every day. In this paper we report the results of dosimetric measurements made on board the ISS during Expedition-8, -9 and -10 using the “Pille” portable thermoluminescent detector (TLD) system and we compare them with our previous measurements on different space stations. [Copyright &y& Elsevier]

Abstract: Shielding is arguably the main countermeasure for the exposure to cosmic radiation during interplanetary exploratory missions. However, shielding of cosmic rays, both of galactic or solar origin, is problematic, because of the high energy of the charged particles involved and the nuclear fragmentation occurring in shielding materials. Although computer codes can predict the shield performance in space, there is a lack of biological and physical measurements to benchmark the codes. An attractive alternative to passive, bulk material shielding is the use of electromagnetic fields to deflect the charged particles from the spacecraft target. Active shielding concepts based on electrostatic fields, plasma, or magnetic fields have been proposed in the past years, and should be revised based on recent technological improvements. To address these issues, the European Space Agency (ESA) established a Topical Team (TT) in 2002 including European experts in the field of space radiation shielding and superconducting magnets. The TT identified a number of open research questions to be addressed, including development and testing of novel shielding materials, studies on the angular distributions of energetic solar particles, and cooling systems for magnetic lenses in space. A detailed report to the ESA will be published within a few months. A summary of the TT conclusions and recommendations will be discussed in this paper, with emphasis on active shielding using superconducting magnets. [Copyright &y& Elsevier]

The European Space Agency has recently initiated a study of the human responses, limits and needs with regard to the stress environments of interplanetary and planetary missions. Emphasis has been laid on human health and performance care as well as advanced life support developments including bioregenerative life support systems and environmental monitoring. The overall study goals were as follows: (i) to define reference scenarios for a European participation in human exploration and to estimate their influence on the life sciences and life support requirements; (ii) for selected mission scenarios, to critically assess the limiting factors for human health, wellbeing, and performance and to recommend relevant countermeasures; (iii) for selected mission scenarios, to critically assess the potential of advanced life support developments and to propose a European strategy including terrestrial applications; (iv) to critically assess the feasibility of existing facilities and technologies on ground and in space as testbeds in preparation for human exploratory missions and to develop a test plan for ground and space campaigns; (v) to develop a roadmap for a future European strategy towards human exploratory missions, including preparatory activities and terrestrial applications and benefits. This paper covers the part of the HUMEX study dealing with lunar missions. A lunar base at the south pole where long-time sunlight and potential water ice deposits could be assumed was selected as the Moon reference scenario. The impact on human health, performance and well being has been investigated from the view point of the effects of microgravity (during space travel), reduced gravity (on the Moon) and abrupt gravity changes (during launch and landing), of the effects of cosmic radiation including solar particle events, of psychological issues as well as general health care. Countermeasures as well as necessary research using ground-based test beds and/or the International Space Station have been defined. Likewise advanced life support systems with a high degree of autonomy and regenerative capacity and synergy effects were considered where bioregenerative life support systems and biodiagnostic systems become essential. Finally, a European strategy leading to a potential European participation in future human exploratory missions has been recommended. [Copyright &y& Elsevier]

Exposure of crew to the space radiation environment poses one of the most significant problems in long term missions in low earth orbits and in interplanetary missions. Accurate personal dose measurement will become increasingly important especially during manned missions to Mars. A series of instruments suitable for on-board dose, flux and LET measurements has been developed by the authors''. Based on the experience gained so far from their utilization, an instrument consisting of a thermoluminescent device and a dosimetry telescope is proposed for the use on the International Space Station and for human Mars missions. The short technical description of this instrument is given in this paper. [Copyright &y& Elsevier]

Stacks of CR-39 plastic nuclear track detectors were mounted inside the MIR spacecraft during the EUROMIR95 space mission for a period of 6 months. This long exposure time resulted in a large number of tracks of HZE-particles in the detector foils. All trajectories of stopping iron nuclei could be reconstructed by optimizing the etching conditions so that an automatic track measurement using image analysis techniques was possible. We found 185 stopping iron nuclei and used the e´nergy-range relation to calculate their energies at the stack surface. The measured spectrum of iron nuclei inside the MIR station is compared to results of model predictions considering the effect of the solar modulation for the mission period, the geomagnetic shielding effect for the MIR orbit and the shielding by material of the spacecraft walls and its instrumentation. [Copyright &y& Elsevier]

Following the publication of the joint The International Commissions on Radiation Units and Measurements (ICRU) and on Radiological Protection (ICRP) report on new operational quantities for radiation protection, the European Dosimetry Group (EURADOS) have carried out an initial evaluation. The EURADOS report analyses the impact that the new quantities will have on: radiation protection practice; calibration and reference fields; European and national regulation; international standards and, especially, dosemeter and instrument design. The task group included experienced scientists drawn from across the various EURADOS working groups., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)