Susana Zanello is an expert in adapting humans to life in space. Invited as a guest at the Ecole Federal Lausanne (EPFL), she shared her perspective on exploration, space exploration, future travel to Mars and more. We are publishing the interview presented on Phys.org.
Space travel affects the human body much more strongly than we think. Susana Zanello specializes in these effects. A biologist, she works for the Division of Space Life Sciences in Houston, an institution that supports NASA's work. Its mission is to study human adaptation to life in space, identify the associated risks and develop countermeasures to keep astronauts healthy as they conduct reconnaissance missions.
How will this EPFL stay help your research?
I came here to learn more about miniaturization and collect some ideas. In space medicine, we need devices with small dimensions that will allow in-flight analyzes and real-time health monitoring: to measure the pulse, blood pressure, respiration rate and temperature of astronauts. In addition, there must be some way to collect health data for the entire crew. This is an important point, since there are a lot of restrictions in space: available space, crew time, the weight of objects that we take there. So we are looking for new micro and nanotechnology to make smaller and better devices.
What are the most important manifestations of space flight in the body?
Living outside the Earth is a challenge. In the process of evolution, life has adapted to this planet. In space, one of the main risks is microgravity - the absence of gravity. The obvious consequence is the loss of bone mineral density. Up there, you just don't have to constantly struggle with the force of gravity, as we do on Earth.
Thus, the skeleton simply does not need to support us. The human body begins to adapt by reducing the density of the bone matrix and processing calcium differently. This leads to a loss of bone strength, which increases the risk of fractures when you return to Earth, as well as kidney stones.
Cosmic radiation is another important risk to life in space. The Earth's magnetic field is an effective shield, preventing most high-energy particles from reaching the planet's surface. Outside the Van Allen belts or on other planets, we will be constantly bombarded by powerful solar protons and galactic cosmic rays.
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There is strong evidence that they can pass through our bodies and interact with DNA. In the long term, there is a risk associated with DNA changes, cancer, so serious research is needed.
Is your work focused on changes in the vision of astronauts?
In the early 2000s, we began to observe a decrease in the visual acuity of astronauts after they spent time on the ISS, the International Space Station. Further research showed changes in the shape of the eyes, a flattening of the eyeball, and a thickening of the back of the eye at the beginning of the optic nerve. 60% of astronauts experience vision loss, in some cases it is irreversible. Therefore, NASA considers this a high priority health risk.
What is causing this loss of vision?
We think this is due to the displacement of fluids in the body. On Earth, fluids tend to move towards the feet. Their movement and valves in our leg veins help pump blood back to the heart. In microgravity, this system is no longer needed and your fluid is pumped into your head instead.
This leads to the appearance of a puffy face and chicken legs, as well as, possibly, to increased intracranial pressure. Scientists speculate that when the pressure in the cerebrospinal fluid rises, it changes the pressure in the eyes, which affects visual acuity.
What kind of research are you going to do in the future?
There are physiological signs of adaptation that we can observe, as well as those underlying them at the molecular level. Genes can be expressed in different ways in space, resulting in certain physiological changes. The research I'm doing right now should answer these questions. But again, there are many limitations to doing experiments in space.
Now astronauts live there for up to six months, and only two of them decided on a one-year mission. But when we talk about other distant destinations like Mars, it speaks of the need for long missions. To find out what can happen on such voyages, we need to conduct experiments not only on the ISS, but also on terrestrial analogs of space bases, on platforms that simulate the conditions of space.
What are the main challenges of traveling to Mars?
Such a mission will take at least three years. The first risk is physiological. To measure it, we need to take into account duration, distance, isolation, confinement with a limited number of people, the stress of high workload, and the pressure of having to succeed. Once you arrive on Mars, it's better: partial gravity. Your bones will receive immediate stimulation and the rate of drop in bone density will decrease. But again, on the surface, astronauts face the risk of high-energy radiation. Not to mention the harsh climate, dust and the need for good food.
How about other planets?
Of course, we are starting to think about more distant objects like Jupiter's moon Europa, on which water was discovered. But he is much further. Plus, believe it or not, while Mars appears to be a dead planet, it is still relatively friendly compared to the rest. Its size and rotation is similar to that of the Earth. The day lasts almost 24 hours. This is important for people who are used to living in such conditions. Living on a planet with 10-hour days, for example, can cause many side effects for the body.
Are we too accustomed to earthly conditions to fly into space?
Experience shows that we can adapt to a new environment. Of course, there will always be certain risks. We must carefully determine the levels of these potential risks. But we cannot ignore the thirst for human exploration. Even with a high risk, there is always someone who wants to rush into the new and unknown.