Abstract
After having been an instrument of the Cold War, space exploration has become a major technological, scientific and societal challenge for a number of countries. With new projects to return to the Moon and go to Mars, radiobiologists have been called upon to better assess the risks linked to exposure to radiation emitted from space (IRS), one of the major hazards for astronauts. To this aim, a major task is to identify the specificities of the different sources of IRS that concern astronauts. By considering the probabilities of the impact of IRS against spacecraft shielding, three conclusions can be drawn: (1) The impacts of heavy ions are rare and their contribution to radiation dose may be low during low Earth orbit; (2) secondary particles, including neutrons emitted at low energy from the spacecraft shielding, may be common in deep space and may preferentially target surface tissues such as the eyes and skin; (3) a “bath of radiation” composed of residual rays and fast neutrons inside the spacecraft may present a concern for deep tissues such as bones and the cardiovascular system. Hence, skin melanoma, cataracts, loss of bone mass, and aging of the cardiovascular system are possible, dependent on the dose, dose-rate, and individual factors. This suggests that both radiosusceptibility and radiodegeneration may be concerns related to space exploration. In addition, in the particular case of extreme solar events, radiosensitivity reactions—such as those observed in acute radiation syndrome—may occur and affect blood composition, gastrointestinal and neurologic systems. This review summarizes the specificities of space radiobiology and opens the debate as regards refinements of current radiation protection concepts that will be useful for the better estimation of risks.
Highlights
To date, exposure to ionizing radiation (IR) is one of the major concerns for space exploration [1,2,3,4]
Since space missions generally correspond to exposure to low-dose radiation, space radiobiology should integrate the uncertainties related to rare physical events, the specificity of some radiobiological phenomena occurring at low-doses, and their contribution to radiation-induced risks [6]
Unlike the syndromes associated with radiosensitivity, the syndromes associated with cancer proneness and radiosusceptibility are generally caused by heterozygous gene mutations and their related clinical features may not be detectable without DNA sequencing before cancer occurrence
Summary
Exposure to ionizing radiation (IR) is one of the major concerns for space exploration [1,2,3,4]. The data generated by the first Explorer and Pioneer satellites permitted Van Allen and Franck to point out the existence of the Earth’s radiation belt; that is, a high intensity band of corpuscular radiation temporarily trapped in the Earth’s magnetic field, the Van Allen radiation belt They revealed, thereafter, that this belt is composed of protons and electrons that are mainly generated as secondary particles from neutrons emitted from cosmic charged particles [13,14]. Numerous hypotheses were formulated about the injuries that such particle flux may cause on electronics, materials, and overall, on human health at each passage above the SAA From this period, on-board radiation dosimetry was systematically set up for each space mission [16,17,18]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
