As we plan to go back on the moon and beyond, we must look back at a few factors that could risk an astronaut's health in space. Space exploration is one of humanity's most outstanding achievements. Still, it also poses significant risks, such as radiation, space debris, equipment malfunction, the weird effects of weightlessness, being far away, etc. Among them, radiation exposure is the most critical and serious risk for astronauts and, simultaneously, the least visible threat. Within Earth’s atmosphere, because of the magnetic field, we are protected from this high level of cosmic radiation, which is not there for astronauts and can profoundly affect their health and mission success. Before we understand how to protect our astronauts from this, let us know the sources of this cosmic radiation[1].
Radiation has two primary sources:
Galactic Cosmic Rays (GCRs)
Solar particle events
Let us first understand what the galactic cosmic rays are. They mostly started beyond our solar system, like from supernovas or other celestial phenomena. Solar particles from our sun also exist concurrently. The sun's energy surge is usually connected with solar flares and coronal mass ejections. Primarily consisting of protons, they may rapidly provide intense radiation. The magnetic field and atmosphere of Earth protect humans from some radiation sources. But astronauts, particularly on long-term trips to the Moon, Mars, or beyond, are vulnerable to much greater radiation levels in space[2].
Radiation's effects on astronauts
Radiation in orbit could cause both immediate and long-term health problems for astronauts. Type, dose, and period of exposure determine the consequences.
Short-Term Effects: Acute Radiation Syndrome
Among the symptoms are nausea, vomiting, exhaustion, and skin irritability.
Causes: Strong radiation levels during solar particle eruptions or unprotected contact
Impact: These symptoms can make an astronaut unable to carry out essential activities, compromising the mission's success.
Extended Effects
Especially in organs like the lungs, stomach, and breasts, extended cosmic radiation increases a cancer risk.
High-energy particles can destroy brain cells, triggering cognitive decline, memory loss, and impairment of motor function.
Radiation can impair blood vessels and the heart, therefore increasing the risk of heart disease and stroke.
The higher radiation level seen by astronauts raises their chance of developing cataracts.
3. Reproductive and Genetic Conventions
Damage of DNA by radiation could result in mutations that will influence the next generations.
Astronauts intending to have children following extended missions have questions about this.
Difficulties of Radiance in Space
Preparing for high radiation dosages is challenging due to the unpredictable nature of solar particle events. Current spaceship shielding cannot catch all cosmic radiation, especially heavy ions. The radiation level rises with longer voyages, such as those to Mars[3].
Space agencies like NASA and ESA are researching new ways to shield people from radiation. Some ideas for strategies are making drugs that protect cells or fix DNA that has been damaged, designing spacecraft with specific radiation shelters and real-time radiation monitors, limiting missions to deep space, planning missions for times when the sun isn't active, and building homes on Mars or the Moon with thick walls made of regolith.
Research into radiation shielding is crucial as humans prepare for lengthy trips to the Moon and Mars. Radiation is an invisible but significant challenge to space flight. Although radiation seriously affects astronauts, new technologies and research promise safer space flight. Awareness of and lowering these risks will help us ensure that astronauts remain fit and competent as they push the boundaries of human exploration and open the path to a future among the stars.
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Author: Mahima Gehlot