The Impact of Space Environment

Three years without the protective embrace of Earth is a daunting prospect for anyone.

Earth provides a safety net that no other planet in our solar system can match, including its gravitational and magnetic fields. The magnetic field shields us from the majority of solar wind and protects against harmful radiation fluctuations that bombard other inner planets. Our atmosphere is sustained by this magnetic barrier, which keeps high-energy particles from stripping it away. We can visualize this magnetic field as Earth's own defensive shield, which is evident in phenomena like the aurora borealis.

Once astronauts venture beyond Earth's atmosphere, these energetic particles can penetrate the metal structure of their spacecraft. Solar energetic particles can inflict direct damage to human DNA, potentially resulting in acute radiation sickness or cancer. Research indicates clear evidence of DNA damage from space radiation, demonstrated by experiments with HeLa cells aboard a Russian space station, which showed a direct link between flight duration and radiation exposure. The length of exposure is crucial as it correlates with the severity of damage, such as chromosomal changes in white blood cells after extended space missions.

Studies also suggest increased risks for cardiovascular diseases and cognitive decline. Given that three years of exposure to unfiltered cosmic radiation far exceeds the few months typically studied, we lack definitive knowledge about the extent of damage to human health, leading to concerns about long-term quality of life for survivors post-mission.

NASA is exploring solutions to these challenges, but they admit that more work is needed. Sheila Thibeault, a materials researcher at NASA, acknowledges, “We’ve made progress in developing shielding against these energetic particles, but we’re still searching for effective materials.” Some potential solutions include polyethylene, commonly found in plastic bottles, which is inexpensive and effective due to its high hydrogen content. Another candidate, hydrogenated boron nitride nanotubes (BNNTs), consists of tiny tubes that can absorb neutrons, making them promising for protective gear.

Additionally, research into medications that could mitigate radiation damage is ongoing, though preventing exposure remains the best approach.

The Challenges of Microgravity

The absence of gravity poses another significant hurdle. Humans are inherently adapted to function in gravitational environments, and without it, vital bodily processes, such as fluid circulation, can become problematic. Muscles and bones weaken, necessitating that current astronauts aboard the International Space Station exercise for several hours daily to maintain their physical strength. In space, changes in intracranial pressure can lead to issues such as vision problems and balance difficulties.

Moreover, the body’s natural cell death regulation becomes disrupted, leading to uncontrolled cell growth, which poses a risk in the event of complications during a prolonged flight.

NASA’s solution involves a lower body negative pressure chamber (LBNP), which applies pressure to the lower body to draw fluids downward, mimicking Earth-like intracranial pressure. However, the long-term effects of such treatments remain unknown. Alan Hargens, a space physiologist at the University of California, San Diego, explains, “We don’t know how much time [in LBNP] is required to protect the body from fluid shifts in space.” His team has developed a prototype LBNP suit for daily use, describing it as “an early form of artificial gravity.”

Addressing Astronaut Well-being

How will astronauts manage their medical and psychological needs during such a lengthy journey?

Even with a physician on board, there’s no certainty they could handle unprecedented challenges. A small company named VisualDX is addressing this issue, with funding from NASA, to adapt its online diagnostic tool for use in deep space. They are creating a system that functions offline and focuses on medical issues more likely to arise for astronauts, eliminating the need for constant communication with Earth.

This tool, when combined with the Autonomous Medical Officer Support (AMOS) system, will enable non-medical personnel to perform essential procedures like inserting breathing tubes. Astronauts on the International Space Station are currently testing these technologies to evaluate their effectiveness compared to relying on Earth-based medical advice. The vast distance between Mars and Earth means that even messages sent at light speed would take minutes to reach their destination.

Significant advancements are being made in biomedical fields to ensure human survival during a three-year mission to another planet; however, it remains impossible to plan for every contingency. Erik Antonsen, an emergency medicine physician and aerospace engineer at NASA, states:

“The moon is like a camping trip compared to a journey to Mars. When we embark on the first missions to Mars, there’s a substantial risk that someone may not survive.”

There are still many unknowns, and the longest human presence on the moon has been just three days, making it a far more attainable objective than Mars.

While various technologies are in development to address the challenges of potential human missions to Mars, many medical tools and devices remain unprepared for such a venture. It is likely that these advancements will not be fully realized for another decade or two. Consequently, the notion of colonizing Mars appears more like a distant dream, a sentiment echoed by NASA, which currently envisions a human mission to Mars in the 2030s.