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PubMedDate not supplied

Space flight effects on bacterial physiology.

The study of bacterial behavior under space flight conditions is highly important for the early detection of changes in bacterial communities and bacteria with medical, environmental, or life support consequences for survival of the crew in closed space environments. Although many species of prokaryotes have been studied in ground simulation facilities or have been flown in space flights, at present only few hard research data are available to predict the effects of cosmic radiation, microgravity, vibration and hypervelocity on microbial behavior in space flight. The results that are available tend to be fragmentary and often lack a classical, controlled experimental context to interpret them. Thus, many basic questions concerning the effects of space on microbial behavior have yet to be resolved.

Bacteria↗

PubMed1981

Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds.

We have studied the effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions. The data obtained evidence a significant fourfold increase of spontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight.

Chromosome Aberrations↗

PubMed2002

Cancer incidence in California flight attendants (United States).

OBJECTIVE: To examine unusual exposure opportunities to flight crews from chemicals, cosmic radiation, and electric and magnetic fields. METHODS: This project evaluated the incidence of cancers of the breast and other sites among Association of Flight Attendants (AFA) members residing in California. AFA membership files were matched to California's statewide cancer registry to identify a total of 129 newly diagnosed invasive cancers among AFA members with California residential histories between 1988 and 1995. RESULTS: Compared to the general population, female breast cancer incidence was over 30% higher than expected, and malignant melanoma incidence was roughly twice that expected. Both of these are cancers that are associated with higher socioeconomic status and have been suggestively associated with various sources of radiation. CONCLUSIONS: Consistent with the results from Nordic studies of cabin crews and a recent meta-analysis of prior studies, these data suggest that follow-up investigations should focus on the potential relative contribution of workplace exposures and lifestyle characteristics to the higher rates of disease for these two cancers.

Adult↗

PubMed1986

Bioscience experiments in the German Spacelab mission D-1: introduction and summary.

The German Spacelab mission D-l was performed from 30 October through 6 November 1985. Payload operation in orbit was managed by DFVLR for the Federal Ministry of Research and Technology. The scientific program of the mission placed emphasis on microgravity research. In bioscience, the role of gravity in vital functions of biological systems was investigated, such as intracellular and intercellular interactions, developmental processes as well as regulation and adaptation in highly organized systems including human beings. In addition, the biological significance of cosmic radiation or altered zeitgeber within the complex matrix of all relevant spaceflight components were studied. Most of the experiments were accommodated in the following three payload elements: The Bioscience Experiment Package, and the ESA facilities Vestibular Sled and BIORACK. The information gained from the individual experiments will be compiled to help answer pending questions of space bioscience.

Adaptation, Physiological↗

PubMed2001

The possible effects on health, comfort and safety of aircraft cabin environments.

A consultation was undertaken to investigate the views and concerns of stakeholders in the aircraft industry about the possible harmful effects on personal health, comfort and safety of aircraft cabin environments. Stakeholders were identified from a variety of sources including Government agencies, the Internet, House of Lords inquiry, and suggestions of interviewees. They represented: aircraft crews, aircraft constructors and engineers, government departments and authorities, holiday/flight companies, insurance companies, non-governmental organisations, occupational health physicians, passenger representatives, and independent researchers and consultants. Eighty-seven were contacted of which 57 were interviewed over the telephone using a semi-structured questionnaire. Their concerns were transcribed into a standard format and analysed qualitatively. Key stakeholders, along with Government officials, were invited to a workshop to discuss and prioritize the issues raised during the interviews. The main concerns expressed by the participants fell into five main areas: deep vein thrombosis, air quality, infection, cosmic radiation, and jet lag and work patterns. In addition, a number of safety concerns were raised as well as comments on the provision of appropriate advice to passengers. It was generally felt that further research was required on each of these subjects, as well as an improvement in the quality, quantity and availability of information provided for passengers prior to boarding a flight.

Air Pollution, Indoor↗

PubMed2002

Dose measurements in space by the Hungarian Pille TLD system.

Exposure of crew, equipment, and experiments to the ambient space radiation environment in low Earth orbit poses one of the most significant problems to long-term space habitation. Accurate dose measurement has become increasingly important during the assembly (extravehicular activity (EVA)) and operation of space stations such as on Space Station Mir. Passive integrating detector systems such as thermoluminescent dosemeters (TLDs) are commonly used for dosimetry mapping and personal dosimetry on space vehicles. The well-known advantages of passive detector systems are their independence of power supply, small dimensions, high sensitivity, good stability, wide measuring range, resistance to environmental effects, and relatively low cost. Nevertheless, they have the general disadvantage that for evaluation purposes they need a laboratory or large--in mass and power consumption--terrestrial equipment, and consequently they cannot provide time-resolved dose data during long-term space flights. KFKI Atomic Energy Research Institute (KFKI AEKI) has developed and manufactured a series of thermoluminescent dosemeter systems for measuring cosmic radiation doses in the 10 microGy to 10 Gy range, consisting of a set of bulb dosemeters and a compact, self-contained, TLD reader suitable for on-board evaluation of the dosemeters. By means of such a system, highly accurate measurements were carried out on board the Salyut-6, -7 and Mir Space Stations as well as on the Space Shuttle. A detailed description of the system is given and the comprehensive results of these measurements are summarised.

Astronauts↗

PubMed2002

Space radiation absorbed dose distribution in a human phantom.

The radiation risk to astronauts has always been based on measurements using passive thermoluminescent dosimeters (TLDs). The skin dose is converted to dose equivalent using an average radiation quality factor based on model calculations. The radiological risk estimates, however, are based on organ and tissue doses. This paper describes results from the first space flight (STS-91, 51.65 degrees inclination and approximately 380 km altitude) of a fully instrumented Alderson Rando phantom torso (with head) to relate the skin dose to organ doses. Spatial distributions of absorbed dose in 34 1-inch-thick sections measured using TLDs are described. There is about a 30% change in dose as one moves from the front to the back of the phantom body. Small active dosimeters were developed specifically to provide time-resolved measurements of absorbed dose rates and quality factors at five organ locations (brain, thyroid, heart/lung, stomach and colon) inside the phantom. Using these dosimeters, it was possible to separate the trapped-proton and the galactic cosmic radiation components of the doses. A tissue-equivalent proportional counter (TEPC) and a charged-particle directional spectrometer (CPDS) were flown next to the phantom torso to provide data on the incident internal radiation environment. Accurate models of the shielding distributions at the site of the TEPC, the CPDS and a scalable Computerized Anatomical Male (CAM) model of the phantom torso were developed. These measurements provided a comprehensive data set to map the dose distribution inside a human phantom, and to assess the accuracy and validity of radiation transport models throughout the human body. The results show that for the conditions in the International Space Station (ISS) orbit during periods near the solar minimum, the ratio of the blood-forming organ dose rate to the skin absorbed dose rate is about 80%, and the ratio of the dose equivalents is almost one. The results show that the GCR model dose-rate predictions are 20% lower than the observations. Assuming that the trapped-belt models lead to a correct orbit-averaged energy spectrum, the measurements of dose rates inside the phantom cannot be fully understood. Passive measurements using 6Li- and 7Li-based detectors on the astronauts and inside the brain and thyroid of the phantom show the presence of a significant contribution due to thermal neutrons, an area requiring additional study.

Abdomen↗

PubMed2002

Shuttle radiation dose measurements in the International Space Station orbits.

The International Space Station (ISS) is now a reality with the start of a permanent human presence on board. Radiation presents a serious risk to the health and safety of the astronauts, and there is a clear requirement for estimating their exposures prior to and after flights. Predictions of the dose rate at times other than solar minimum or solar maximum have not been possible, because there has been no method to calculate the trapped-particle spectrum at intermediate times. Over the last few years, a tissue-equivalent proportional counter (TEPC) has been flown at a fixed mid-deck location on board the Space Shuttle in 51.65 degrees inclination flights. These flights have provided data that cover the expected changes in the dose rates due to changes in altitude and changes in solar activity from the solar minimum to the solar maximum of the current 23rd solar cycle. Based on these data, a simple function of the solar deceleration potential has been derived that can be used to predict the galactic cosmic radiation (GCR) dose rates to within +/-10%. For altitudes to be covered by the ISS, the dose rate due to the trapped particles is found to be a power-law function, rho(-2/3), of the atmospheric density, rho. This relationship can be used to predict trapped dose rates inside these spacecraft to +/-10% throughout the solar cycle. Thus, given the shielding distribution for a location inside the Space Shuttle or inside an ISS module, this approach can be used to predict the combined GCR + trapped dose rate to better than +/-15% for quiet solar conditions.

Algorithms↗

PubMed1980

Predicted LET-spectra of HZE-particles for the Free Flyer Biostack Experiment on the long duration exposure facility mission.

The LDEF (long duration exposure facility) mission, scheduled for a launch on the Space Shuttle in 1981, will fly for about 9 months in a near-earth orbit with an inclination angle of 28 degrees. In this flight the Free Flyer Biostack Experiment has the objective of measuring the biological effects of individual heavy ions from cosmic radiation (HZE particles). This paper presents results of a calculation of LET-spectra in free space and within the absorber of the experiment. The calculation considers the geomagnetic shielding of the space craft against charged particles with low energies and the disintegration of the heavy ions within the absorbing material by fragmentation. For this mission the LET spectra turn out to differ from those of previous experiments. The steepness of the spectra changes significantly with LET and also with depth of absorber.

Biological Science Disciplines↗

PubMed1993

Fungi in space--literature survey on fungi used for space research.

A complete review of the scientific literature on experiments involving fungi in space is presented. This review begins with balloon experiments around 1935 which carried fungal spores, rocket experiments in the 1950's and 60's, satellite and moon expeditions, long-time orbit experiments and Spacelab missions in the 1980's and 90's. All these missions were aimed at examining the influence of cosmic radiation and weightlessness on genetic, physiological, and morphogenetic processes. During the 2nd German Spacelab mission (D-2, April/May 1993), the experiment FUNGI provided the facilities to cultivate higher basidiomycetes over a period of 10 d in orbit, document gravimorphogenesis and chemically fix fruiting bodies under weightlessness for subsequent ultrastructural analysis. This review shows the necessity of space travel for research on the graviperception of higher fungi and demonstrates the novelty of the experiment FUNGI performed within the framework of the D-2 mission.

Cosmic Radiation↗

PubMed1998

Depth dependence of absorbed dose, dose equivalent and linear energy transfer spectra of galactic and trapped particles in polyethylene and comparison with calculations of models.

A matched set of five tissue-equivalent proportional counters (TEPCs), embedded at the centers of 0 (bare), 3, 5, 8 and 12-inch-diameter polyethylene spheres, were flown on the Shuttle flight STS-81 (inclination 51.65 degrees, altitude approximately 400 km). The data obtained were separated into contributions from trapped protons and galactic cosmic radiation (GCR). From the measured linear energy transfer (LET) spectra, the absorbed dose and dose-equivalent rates were calculated. The results were compared to calculations made with the radiation transport model HZETRN/NUCFRG2, using the GCR free-space spectra, orbit-averaged geomagnetic transmission function and Shuttle shielding distributions. The comparison shows that the model fits the dose rates to a root mean square (rms) error of 5%, and dose-equivalent rates to an rms error of 10%. Fairly good agreement between the LET spectra was found; however, differences are seen at both low and high LET. These differences can be understood as due to the combined effects of chord-length variation and detector response function. These results rule out a number of radiation transport/nuclear fragmentation models. Similar comparisons of trapped-proton dose rates were made between calculations made with the proton transport model BRYNTRN using the AP-8 MIN trapped-proton model and Shuttle shielding distributions. The predictions of absorbed dose and dose-equivalent rates are fairly good. However, the prediction of the LET spectra below approximately 30 keV/microm shows the need to improve the AP-8 model. These results have strong implications for shielding requirements for an interplanetary manned mission.

Cosmic Radiation↗

PubMed1981

A new thermoluminescent dosimeter system for space research.

A small, portable, vibration and shock resistant thermoluminescent dosimeter system was developed to measure cosmic radiation dose on board a spacecraft. The system consists of a small battery-operated reader and a special bulb dosimeter. Doses from 10 microGy up to 100 mGy can be measured. The electrical power consumption of the reader is about 5 W, its volume is about 1 dm3 and its mass is about 1 kg. Details are given for the construction and technical parameters of the dosimeter and reader.

Calcium Sulfate↗

PubMed1986

Track structure in biological models.

High-energy heavy ions in the galactic cosmic radiation (HZE particles) may pose a special risk during long term manned space flights outside the sheltering confines of the earth's geomagnetic field. These particles are highly ionizing, and they and their nuclear secondaries can penetrate many centimeters of body tissue. The three dimensional patterns of ionizations they create as they lose energy are referred to as their track structure. Several models of biological action on mammalian cells attempt to treat track structure or related quantities in their formulation. The methods by which they do this are reviewed. The proximity function is introduced in connection with the theory of Dual Radiation Action (DRA). The ion-gamma kill (IGK) model introduces the radial energy-density distribution, which is a smooth function characterizing both the magnitude and extension of a charged particle track. The lethal, potentially lethal (LPL) model introduces lambda, the mean distance between relevant ion clusters or biochemical species along the track. Since very localized energy depositions (within approximately 10 nm) are emphasized, the proximity function as defined in the DRA model is not of utility in characterizing track structure in the LPL formulation.

Animals↗

PubMed2006

Fresh new air in space? 'MoMa' on the A.S.I. launch pad.

The present project has been developed because of the desire to unify the research lines in the A.S.I. 'Medicine & Biotechnology' area into one research line that could satisfy the interests of all of the collaborative groups and at the same time could pursue a relevant social goal. A 6 month feasibility study (SF) called MoMa was carried out in the ASI framework. During the SF the know-how and the tools already available in the national scientific community have been assessed, selected and evaluated even with the important contribution of Small and Medium-size Enterprises (SME) and of Italian industries already involved in Space Research. As result of the SF MoMa, all of the participants decided to combine all the efforts together and define, with all the know-how and the available technologies, one strategic topic, the "Aging" with a special attention to the Quality of Life (QoL). The space environment is a unique laboratory to study the reaction of living organisms (especially humans) to microgravity and cosmic radiation. The study of the effects of these two variables at the molecular and cellular levels will shed light on the response of cells and living organisms to adverse stimulations that are always present even on Earth and will help us able to develop the best strategies to protect the organisms from the progressive structural and functional decline related to Aging. Relevant spin-offs on Earth and also relevant industrial applications are the expected outputs of this project.

Aging↗

PubMed1991

Real time quality factor and dose equivalent meter "CIRCE" and its use on-board the Soviet orbital station "MIR".

During the French-Soviet space mission "Aragatz," the experiment CIRCE (Compteur Integrateur de Rayonnement Complexe dans l'Espace) recorded the dose rate and quality factor values inside the MIR station. This paper presents results obtained with a new active dose equivalent meter based on microdosimetric techniques and using a low pressure tissue equivalent proportional counter. In terms of lineal energy CIRCE device works in the 0.2-1200 keV micrometer-1 range in tissue. Preliminary studies were performed in photon, neutron and heavy ion beams, and in the real stratosphere cosmic radiation field. Long term measurements on-board MIR station from December 1988 to April 1989 gave an average quality factor value equal to 1.9 +/- 0.3. Through the South Atlantic Anomaly (SAA), the quality factor was equal to 1.4. The temporal orbital variations of the dose rates and quality factors have been established in space dosimetry for the first time.

Cosmic Radiation↗

PubMed1996

Intercomparison of radiation measurements on STS-63.

A joint NASA Russia study of the radiation environment inside the Space Shuttle was performed on STS-63. This was the second flight under the Shuttle-Mir Science Program (Phase 1). The Shuttle was launched on 2 February 1995, in a 51.65 degrees inclination orbit and landed at Kennedy Space Center on 11 February 1995, for a total flight duration of 8.27 days. The Shuttle carried a complement of both passive and active detectors distributed throughout the Shuttle volume. The crew exposure varied from 1962 to 2790 microGy with an average of 2265.8 microGy or 273.98 microGy/day. Crew exposures varied by a factor of 1.4, which is higher than usual for STS mission. The flight altitude varied from 314 to 395 km and provided a unique opportunity to obtain dose variation with altitude. Measurements of the average east-west dose variation were made using two active solid state detectors. The dose rate in the Spacehab locker, measured using a tissue equivalent proportional counter (TEPC), was 413.3 microGy/day, consistent with measurements made using thermoluminescent detectors (TLDs) in the same locker. The average quality factor was 2.33, and although it was higher than model calculations, it was consistent with values derived from high temperature peaks in TLDs. The dose rate due to galactic cosmic radiation was 110.6 microGy/day and agreed with model calculations. The dose rate from trapped particles was 302.7 microGy/day, nearly a factor of 2 lower than the prediction of the AP8 model. The neutrons in the intermediate energy range of 1-20 MeV contributed 13 microGy/day and 156 microSv/day, respectively. Analysis of data from the charged particle spectrometer has not yet been completed.

Atlantic Ocean↗

PubMed1990

Biokosmos 8 experiment: dosimetric measurements with AgCl track detectors behind low shielding.

Monocrystalline sheets of AgCl nuclear track detectors, mounted on top of a detector package, covered by a thin light-filter of 15 micrometers-thick Kapton-foil, were flown in the outside facilities of the Biokosmos 8 Mission. The aim of this lay-out was to record low energy protons and heavy ions, including SAA particles, from the unshielded cosmic radiation. The tracks recorded turned out to be strongly faded. The possible reasons, high temperature (>60 degrees C at the detector surface indicated by temperature markers) or too high temporary intensities of the filtered sunlight, are discussed on the basis of simulation experiments. The report briefly describes: (1) Characteristics of the AgCl-detectors. (2) The lay-out of the experiment, postflight handling and results. (3) Simulation experiments on the ground with respect to the observed fading. (4) A new lay-out proposed for a future analogous experiment with AgCl-detectors.

Atlantic Ocean↗

PubMedDate not supplied

ESA's Biopan 1--"Vitamin" experiment preliminary results.

The purpose of "Vitamin" experiment is to study the efficiency of protective substances on three biological acellular systems aqueous solutions exposed to cosmic radiation in space. The first system "LDL" is a low density lipoprotein. The second is "E2-TeBG complexe" in which estradiol (E2) is bound to its plasmatic carrier protein, testosterone-estradiol binding globulin (TeBG). The third is "pBR 322", a plasmid. "Vitamin" experiment was accommodated in the Biopan which had been mounted on the outer surface of a Foton retrievable satellite. The experiment was exposed to space environment during 15 days. A stable temperature of about 2O degrees C was maintained throughout the flight. "Vitamin" experiment preliminary results are presented and discussed.

Cosmic Radiation↗