Studying the effects of exposure to space radiation is essential to holistically enhance the experience of our future space explorers.

There is much to be studied and understood about space radiation if the human race wants to continue the exploration of space in a safe manner. In fact, the space radiation environment holds vital knowledge required for future space missions and especially, crewed spaceflights. While we know that cosmic radiation can affect our appliances and technologies in various manners, we must also anticipate possible repercussions on the human body. While life on our planet is pretty much shielded from solar and cosmic radiation by Earth’s magnetic fields, we can’t say the same for those traveling beyond our planet’s atmosphere. When a human moves further away from the atmosphere, they can become exposed to the full radiation spectrum and its damaging effects, such as that of the ionizing radiation of radiation belts, such as the Van Allen belt, around our planet.

According to NASA, there are three crucial elements that dictate the effects of radiation on astronauts, namely:

• Altitude above our planet – at higher altitudes above the Earth’s atmosphere, there is less protection against ionizing particles, and spacecrafts tend to pass through radiation belts more often.
• Solar cycle – the Sun goes through an 11-year cycle, which peaks in a staggering number and intensity of solar flares, especially during periods when there are several sunspots.
• Individual bodies – regardless of external factors, sometimes one person can be more susceptible to the effects of space radiation than another.

Despite astronauts wearing protective gear to guard themselves from the detrimental effects of radiation, researchers still worry over the severity of health impacts moderate exposure to high energy radiation particles may bring about in the case of long-term projects in the future, such as lunar and interplanetary missions. In fact, the observations from the ExoMars Trace Gas Orbiter which stipulates that six months on Mars could mean a radiation dose that is 60% of the total limit for an astronaut in their entire career.

The 2006 report by the National Council on Radiation Protection and Measurements (NCRP) on space explorations that stretch past our low-earth orbit (LEO) determined that “current space radiation guidelines pertain only to missions in LEO and are not considered relevant for missions beyond LEO”. As such, we also have to consider defining the radiation risk limits for human exploration beyond the LEO.

Without a doubt, it is vital to study and understand the full extent of the ramifications of space radiation exposure on the human body to ensure a protected and productive human space travel. When radiation can affect any part of the body to the cellular level, NASA’s Human Research Program has concerns over possible health problems, such as cancer, cardiovascular diseases, cognitive impairment and damages to the central nervous system. 

Peter Guida, liaison biologist for NASA Space Radiation Laboratory, states that “the primary means by which radiation affects cells is by damaging DNA – breaks in strands could be experienced.” In explaining the radiation exposure resulting in cancer, she mentions that “DNA bases (adenine, guanine, cytosine, and thymine) can also be knocked out. The cell will make an attempt to repair these damages. Sometimes it’s effective and sometimes it’s not, and sometimes it can be misrepaired. Genes that have been misrepaired can become mutations, and the accumulation of these mutations over time can potentially lead to cancer.”

The space radiation environment not only poses a serious risk to the safety of spacecraft in orbit, but also to human space exploration. And so, understanding the interactions of the space radiation environment is important for holistically enhancing the experience of future space explorers.