Exploring Mars: What's Needed For The Journey? (2024)

The prospect of travelling to Mars has captivated humanity for decades, with the planet being a frequent target of exploration in fiction. However, the reality of reaching the Red Planet is far more complex. The journey to Mars is no easy feat, requiring a vast array of considerations and resources. From the position of Earth and Mars to the technology employed, there are numerous factors that influence the duration and feasibility of the trip.

The distance between Earth and Mars is ever-changing as they orbit the Sun, with the average distance being approximately 140 million miles (225 million km). This distance, along with the available technology, determines the travel time to Mars, which can range from months to years. The journey also necessitates addressing the challenges posed by the unique characteristics of Mars, such as its thin atmosphere and substantial distance from Earth.

Moreover, the human element introduces a host of additional complexities. A human mission to Mars demands careful planning to ensure the availability of essential resources like food, water, and oxygen for the entire duration of the trip. The weight of these supplies can significantly impact the speed of the spacecraft. Furthermore, the human body's ability to withstand the rigours of space travel over extended periods remains a critical concern.

Despite these challenges, the allure of exploring Mars persists, and advancements in technology offer hope for shortening the journey and enhancing the safety of human missions.

Human survival in space

Radiation Exposure

One of the most significant threats to human health in space is radiation. Mars is much farther from the Sun than Earth, but it lacks a strong magnetosphere and has a thin atmosphere, allowing dangerous levels of radiation to reach its surface. This radiation exposure can lead to an increased risk of cancer and other diseases. To protect astronauts, NASA is researching shielding materials and structures, such as hydrogenated boron nitride nanotubes. Additionally, antioxidants and pharmaceuticals are being explored as countermeasures to repair cellular damage caused by radiation.

Microgravity Effects

In microgravity, bodily fluids shift upwards towards the head, causing vision problems and increased intracranial pressure. It also results in muscle weakness and bone loss due to reduced physical load. To counteract these effects, artificial gravity solutions are being developed, such as lower body negative pressure (LBNP) chambers and suits. These technologies aim to simulate the effects of gravity and prevent the negative consequences of prolonged weightlessness.

Diet and Exercise

Astronauts in space face dietary restrictions due to limited food options and the need for nourishment during their journey. Ensuring proper nutrition is crucial for maintaining health and reducing the risk of developing health issues. Regular exercise is also vital to counteracting muscle and bone loss, improving cardiovascular function, and providing psychological benefits.

Psychological Challenges

The psychological effects of isolation and confinement during a long-duration mission cannot be understated. Astronauts will face challenges such as boredom, stress, anxiety, and depression. Maintaining good social relationships and mental resilience is essential for the success of the mission and the well-being of the crew.

Medical Emergencies

With limited access to advanced medical facilities and equipment, addressing medical emergencies in space becomes a complex task. Astronauts will need to be equipped with the knowledge and tools to handle various medical situations, and artificial intelligence systems are being developed to assist in diagnosing and treating illnesses and injuries.

Extreme Conditions on Mars

Mars presents a hostile environment with extremely cold temperatures, toxic dust, and intense radiation. Special habitats, similar to those used in Antarctica, will be necessary to provide warmth and breathable air. Mars's thin atmosphere also allows for planet-wide dust storms, which can block sunlight for weeks and affect electricity generation and communication with Earth.

Technical Failures

The potential failure of propulsion or life-support systems is a constant risk during space missions. Robust and reliable technology is crucial to ensure the safety and survival of astronauts.

Social Dynamics

The social dynamics among crew members in cramped and isolated conditions can lead to interpersonal conflicts and relationship breakdowns. Maintaining positive interactions and effective communication is essential for the success of the mission.

Propulsion technology

The traditional method of propulsion for space missions is chemical propulsion, which comes in two main types: liquid and solid. Liquid propulsion is more efficient and offers more thrust regulation, but solid propulsion is simpler, safer, and cheaper. For example, the traditional Delta II rocket used to propel many NASA missions, including the Mars Exploration Rover, is a form of liquid propulsion.

However, chemical propulsion has its limitations, and alternative methods are being explored. One such alternative is nuclear propulsion, which comes in two forms: nuclear electric and nuclear thermal propulsion. Nuclear electric propulsion uses propellants much more efficiently than chemical rockets but provides lower thrust. Nuclear thermal propulsion, on the other hand, provides high thrust and twice the propellant efficiency of chemical rockets. NASA is currently exploring the possibility of using nuclear propulsion for future crewed missions to Mars, but significant development is still required.

Another alternative to chemical propulsion is electric propulsion, which uses electricity to expel propellant at high speed. This method is more efficient and requires very little mass, but it has lower thrust, meaning more power and time are needed to manoeuvre. Electric propulsion has been used successfully on ESA's BepiColombo, GOCE, and SMART-1 missions.

Other novel propulsion techniques under exploration include lasers, solar sails, and nuclear propulsion. Photon propulsion, which relies on a powerful laser to accelerate a spacecraft to velocities approaching the speed of light, could potentially enable a robotic spacecraft to travel to Mars in just three days.

The choice of propulsion system will depend on various factors, including the mission type, the weight of the spacecraft, and the desired level of efficiency and manoeuvrability. While there have been significant advancements in propulsion technology, there is still room for improvement to reduce the time, cost, and energy requirements of travelling to Mars.

Radiation and other health risks

The health risks posed by radiation exposure are significant and include cancer, cardiovascular diseases, and cognitive and behavioural decrements. The full extent of the risks is not yet fully understood, but NASA has set a career radiation limit for astronauts of 1 sievert, with a 3% risk of exposure-induced death.

On a mission to Mars, astronauts could receive radiation doses up to 700 times higher than on Earth. A recent NASA study found that a round trip to Mars could result in a radiation dose of 0.66 sieverts, close to the limit. The risks are further exacerbated by the long duration of a Mars mission, with astronauts exposed to radiation for up to three years.

The effects of radiation exposure on the human body include damage to the brain, heart, and central nervous system, as well as an increased risk of cancer and degenerative diseases. NASA's Twins Study found that astronaut Scott Kelly, who spent a year in space, exhibited DNA damage compared to his identical twin brother, Mark, who remained on Earth.

In addition to the direct health impacts of radiation, there are also indirect effects. Radiation exposure can cause changes in the central nervous system, leading to altered neurocognitive function, impaired motor function, and neurobehavioural changes. These effects may impact an astronaut's ability to perform their duties during a mission.

The risks associated with radiation exposure are not limited to the astronauts themselves. The potential for radiation contamination of Mars, a planet that may have supported microbial life, is a significant concern. Human missions must take precautions to prevent contamination of the planet and the equipment used to study it.

Overall, radiation and other health risks are critical challenges that must be addressed before human missions to Mars can become a reality. Protecting astronauts from radiation exposure and mitigating the potential impacts on their health and performance are key areas of focus for space agencies and researchers.

The search for life

Mars is a priority in the search for life because it may have been similar to early Earth. Both planets were warm and wet with an atmosphere dominated by carbon dioxide. Volcanoes on both planets released gases containing the elements of organic chemistry: carbon, hydrogen, nitrogen, and oxygen. Meteor impacts could have created the conditions necessary for these atoms to become the building blocks of life.

However, NASA's public interest in finding life on Mars is not reflected in its Mars exploration program, which focuses on geological research. The last time NASA conducted experiments to identify living microbes on Mars was in 1976. The Curiosity rover of 2012 was meant to find out if Mars could support microbial life, and the 2021 Perseverance mission was to collect geological samples and find signs of ancient life. NASA's existing rovers are directed to avoid areas likely to harbor life.

Despite this, some argue that the fear of forward contamination—the possibility of transferring microbes from Earth to Mars—is unfounded. Martian microorganisms would not pose a risk to life on Earth, and if this kind of contamination were possible, it would have already happened due to asteroid impacts on Mars.

Preparing for future human exploration

Scientific and Exploration Objectives:

The primary objective of exploring Mars is to search for past or present life. Mars, being the most Earth-like planet in the Solar System, may hold clues about the potential habitability of other worlds and the origins of life. Understanding the evolution of Mars, including its climate change history, water presence, and geological processes, can provide valuable insights.

Technological Advancements:

To reduce the travel time and cost of human missions to Mars, advancements in propulsion technologies are crucial. NASA and other space agencies are investing in projects to develop more efficient propulsion systems, such as nuclear thermal propulsion and electric propulsion. These innovations aim to reduce travel time and increase mission safety.

Mission Planning and Design:

The design of a crewed mission to Mars requires careful planning and optimization. Factors such as travel duration, fuel consumption, and the weight of supplies and equipment need to be balanced. The use of local resources, such as water, for fuel and consumption by astronauts, can help reduce the overall weight and complexity of the mission.

Health and Safety Considerations:

Exploring Mars poses several health risks to astronauts, including exposure to cosmic rays and other ionizing radiation, loss of kidney function, adverse effects of prolonged weightlessness, and psychological and social impacts of long-duration missions. Developing countermeasures and support systems to mitigate these risks is essential.

International Cooperation and Funding:

The cost of human exploration of Mars is a significant limiting factor. International cooperation and collaboration among space agencies and organizations can help share the financial burden and promote global scientific advancement. Space tourism and technological advancements may also contribute to reducing the funding required.

Planetary Protection and Biohazards:

The potential presence of biohazards in Martian soil and dust needs to be assessed before sending astronauts. Understanding and managing the risks associated with uncontained Martian material brought back to Earth by astronauts is crucial for the safety of both the crew and our planet.

In summary, preparing for future human exploration of Mars involves a multitude of scientific, technological, logistical, and safety considerations. By addressing these challenges and continuing to advance our knowledge and capabilities, we move closer to the goal of successfully sending humans to explore the Red Planet.

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