How much do you know about the dangers of a trip to Mars?

Astronauts to Mars journey is not like tourists to Switzerland so easy, relaxed, and comfortable, but a journey full of uncertainties and unknown risks of adventure. Astronauts on Mars exploration missions will have to fight for a long time against the stresses of deep space radiation, microgravity, claustrophobic space, and isolation.

After all, with current technology, it will take at least six months for astronauts to reach Mars and an equally long time to return to Earth. Therefore, they must be prepared to overcome physical and psychological challenges. The National Aeronautics and Space Administration (NASA) is also working to reduce the risks astronauts may face before they are sent to Mars in the 1930s.

Stressor "synergy"

NASA's Human Research Program (HRP) chief scientist Jennifer Fogarty said earlier this month that astronauts aboard the spacecraft "will have to provide everything and more to meet the astronauts' basic survival needs because we want them to be able to do the job that is extremely demanding in terms of cognitive and physical state," according to a recent report by Space.com. "

HRP's mission is to identify the effects of spaceflight on astronauts and to develop strategies to mitigate and reduce those effects. Fogarty said the project aims to identify five categories of "stressors" that can significantly affect human health and performance during deep space missions, including altered gravity fields, inhospitable environments, radiation, isolation/restraint, distance from Earth, etc.

HRP scientists and other researchers around the world are attempting to carefully analyze and understand all of these stressors by conducting experiments on Earth to carefully monitor the mental and physical health of astronauts working on the International Space Station (ISS). The long-term goal of this work is to help achieve a manned mission to Mars, which NASA hopes to complete by the end of the 1930s. A few years ago, NASA astronauts Scott Kelly and Mikhail Kornienko spent 11 months (about twice the usual length of stay) on the International Space Station to help researchers assess the effects of very long-duration space missions (such as a round-trip trip to Mars) on astronauts.

However, it is very difficult to accurately describe what effects such a trip to Mars would have on astronauts. Fogarty said that because the various stressors of spaceflight are generally not "acting alone" and are likely to be "working in concert," it is almost impossible to put all the risk factors in an experimental setting.

For example, scientists conducting radiation studies on animals in Earth labs do not take into account the effects of microgravity because it cannot be added at this time; and the International Space Station cannot provide deep space radiation data because it operates within the Earth's protective magnetosphere; in addition, installing radiation emitters in orbiting labs does not seem like a good idea.

Radiation is the biggest risk

Some stressors are more worrisome - researchers and NASA officials have repeatedly emphasized that radiation is one of the most dangerous factors facing astronauts on missions to Mars.

One of the biggest challenges for humans going to Mars is the risk of radiation exposure," explained Dr. Lisa Simenson, space radiation element scientist for the HRP program. The health risks that can come from long-term exposure to radiation, which travels through living tissue, deposits energy causing structural damage to DNA and alters many cellular processes."

Studies have shown that exposure to high levels of radiation can increase the risk of cancer in astronauts later in life. A recent study suggests that astronauts on missions to Mars may be exposed to high doses of radiation that accumulate enough to damage their central nervous system, leaving them vulnerable in areas such as mood, memory, and learning ability.

Fogarty mentioned another problem that needs focused research: spaceflight-related neuro-ocular syndrome (SANS), also known as visual impairment/intracranial pressure (VIIP). SANS refers to the fact that spaceflight can cause serious and long-term vision problems for astronauts, possibly due to increased pressure within the skull from fluid flow.

Currently in near-Earth orbit, SANS is very manageable and relatively easy to recover from, but with what we know about the system, it's not enough to predict whether SANS will remain that way on certain exploration missions as well," Fogarty said. So, this is one of the highest priority physiological areas that we are currently studying."

Relying on the moon to get to Mars

NASA's current plan is not to go directly to Mars, but to use the moon as an intermediate station. By 2024, have two astronauts land near the moon's south pole, and shortly thereafter, establish a long-term sustainable base on and around the moon.

NASA officials say they will conduct these activities through the Artemis program, with the primary goal of learning the skills and technologies needed to send astronauts to Mars. "One of the key components of the Artemis infrastructure is a small lunar orbiting space station, the Gateway, which will serve as a hub for activities on the lunar surface. Both robotic and manned landers will descend to the lunar surface from the Gateway, and astronauts on the Gateway outpost will likely operate rovers from there as well.

A large number of studies will be conducted inside the Gateway, most of which will investigate the health and performance of astronauts in a true deep space environment. Fogarty mentioned a research strategy that could be particularly useful in planning the "Road to Mars" - studying small samples of human tissue on a lunar orbiting outpost.

This would circumvent one of the biggest problems affecting research - the use of rodents and other non-human animals as models. How do we bridge the gap between rodents and humans?" says Fogarty. Because it's not directly applicable, this also plagues terrestrial medicine and research. But as organs and tissues on chips continue to emerge and scientists continue to validate them, you can use these chips to outline very complex aspects of the human body. We can use the chip as a model organism to make significant advances in understanding complex environments as a way to address the problem of human limitations."