Scientists are trying to better understand what happens to human bodies in deep space.
Astronauts encounter hazards as they journey through space. Recognizing these hazards allows NASA to seek ways that overcome the challenges of sending humans to the space station, the Moon, Mars, and beyond. Before this, we will need some answers about the impact on human health of exploring deep space.
Kristin Fabre, assistant professor at the Center for Space Medicine, Baylor College of Medicine in Houston, and senior scientist at the Translational Research Institute for Space Health (TRISH) says “We don’t really know what happens to the human body for an extended period of time [in] deep-space exploration.” By extended period of time means that from historic lunar missions are limited to only a few days at a time, whereas a trip to Mars would take months. And the International Space Station (ISS), where humans do regularly spend months in space, lies within Earth’s magnetosphere, which limits the amount and type of exposure to Deep-Space Radiation.
To study the effects on human biology in space, researchers use analogs and simulators on Earth to replicate space conditions. for example, TRISH, is working on a Mars mission simulator to study the physiological effects of prolonged space travel on the human body.
Situated in low Earth orbit (LEO), the ISS is an invaluable research setting because the conditions there still cause fundamental changes in biological systems compared to those on Earth’s surface. NASA’s famous Twins Study tracked biological and mental changes of two identical twin brothers as one orbited in space (Scott) and the other remained firmly on Earth (Mark). The study’s purpose was to determine the effect of spaceflight hazards on the human body. Although numerous changes were cataloged, researchers did note that following Scott’s return to Earth, several of those changes disappeared. Some, however, remained even after six months, including DNA damage from chromosomal inversions, shortened telomeres (which are linked to aging), and attenuated cognitive function.
SPACE CAN BE RISKY
In late 2022, the Artemis I Moon mission successfully launched and returned, heralding a thrilling new era in human space exploration. Humans will soon walk on the Moon for the first time in over 50 years, with plans for lunar outposts. Next up is Mars, a journey that could take up to three years! Ensuring space travelers’ health is crucial for mission success. For instance, an astronaut on the ISS developed a neck vein blood clot but was safely treated with the help of doctors on Earth. Longer missions farther from Earth pose greater health challenges, making medical preparedness vital for future space exploration.
SPACEFLIGHT HAZARDS AND ASSOCIATED HEALTH RISKS
HEALTH RISK 1: CANCER AND OTHER DISEASES FROM SPACE RADIATION
Did you know space is filled with ionizing radiation, powerful enough to break chemical bonds? This space radiation, unlike any on Earth, includes solar particle events from the sun and galactic cosmic rays from beyond our solar system. It can damage cells and tissues of astronauts, potentially leading to health issues like cancer, heart problems, and cognitive impairments. While cancer from space radiation may develop post-mission, scientists are studying if it’s more severe than Earth-induced cancer and how to prevent it. Research at NASA’s Space Radiation Laboratory uses cell cultures and rodents to mimic space conditions and understand these effects. Our knowledge is expanding, but there’s much more to learn about safeguarding human health in space.
HEALTH RISK 2: EYE AND VISION PROBLEMS
Do you or a family member wear glasses? Astronauts often need them too, as space can alter vision. Recently, scientists identified spaceflight associated neuro-ocular syndrome (SANS), a condition specific to space. SANS includes eye nerve swelling and tissue layer folding, impacting clear vision. While SANS hasn’t affected astronauts’ vision pre- or post-mission yet, its impact on longer missions, like a trip to Mars, is under study. Scientists believe fluid shifts in microgravity might be a cause, but more research is needed. They are also examining if SANS affects male and female astronauts differently.
HEALTH RISK 3: CHANGES IN THE BRAIN THAT AFFECT BEHAVIOR, MOOD, AND THINKING ABILITIES
Long space missions, like a journey to Mars, can be incredibly stressful due to isolation, confinement, and limited communication with Earth. These challenges can affect decision-making, teamwork, and mental health, leading to feelings of depression, anxiety, or anger. Fortunately, habits like sleeping well, exercising, journaling, staying connected with loved ones, and positive thinking have proven to reduce stress for astronauts on the International Space Station (ISS). To prepare, scientists use space analogs on Earth, such as the Human Exploration Research Analog (HERA) at NASA’s Johnson Space Center and remote locations like Antarctica. These environments simulate space conditions, helping researchers understand and mitigate the psychological and physical impacts on space travelers, ensuring they stay healthy and resilient.
HEALTH RISK 4: A POOR DIET
A poor diet has long plagued explorers, from sailors suffering scurvy in the 16th-18th centuries to today’s astronauts. Unlike sailors who could restock at ports, space travelers must rely entirely on their supplies. On the ISS, scientists are studying nutrition to prepare for long missions to the Moon and Mars, as poor nutrition can lead to issues like weak bones, cognitive decline, heart problems, and vision loss. Ensuring good nutrition is crucial not only for space health but also for addressing similar issues on Earth.
THE FIVE HAZARDS OF HUMAN SPACE FLIGHT
After all, millions of miles from Earth, going back home for a sick day is not an option!
