Challenges and Benefits of Manned Mission to Mars

Space exploration is a process spurred by human curiosity and the desire for knowledge to traverse the unknown. Other than that, exploring the unknown allows us to generate a greater understanding of the universe and solar system on a level that sanctions technological advances to improve society (NASA, 2013). The history of space exploration started during mid-twentieth century, but the first successful manned mission to space was launched by Russia in 1961. Most famously, the first safe landing on the Moon was achieved in 1969 by the Apollo 11 crew ('The History of Space Exploration - Online Star Register', 2009). Since then, there have been many more attempts made in preparation to explore neighbouring celestial bodies, the closest being Mars with the exception of the Moon. Most missions involved spacecrafts observing and collecting data on Mars, looking for evidence of water, conducting soil and atmosphere analyses, all in an effort to learn more about the Red Planet (NASA, 2019). After decades of robotic exploration, there are discussions of future manned missions to Mars to further explore the planet and it’s satellites with the possibility of terraforming the planet (NASA, 2019). However, like all space missions, there are difficulties and obstacles that must be considered to ensure that the process is successful and more importantly safe for humans.

Challenges

As the aim is to send humans to Mars there are more considerations in the process to ensure that it is successful and safe for astronauts. Like all space missions, there are dangers posed to human life due to the hostile nature of the environment that is not tapered to the basic needs and conditions that we are acclimated to on Earth.

In terms of physical characteristics, Mars is about half the diameter of Earth, with a much lighter gravity and thinner atmosphere. The lower gravity experienced during the trips to and from Mars can also greatly impact the human body (Wei-Haas, 2016). Our bodies, accustomed to Earth’s gravity are constantly working muscles, bones and our heart to keep us functioning. In space, the decreased gravity causes the body to work less in order to function. In comparison to the effort required on Earth, the decrease in energy usage can cause muscle deterioration and the loss of bone density in astronauts (Wei-Haas, 2016). Bones, containing the highest amount of calcium in the body ('High Calcium Levels or Hypercalcemia', 2018), provide blood with a source of calcium. When bone mass is decreased and calcium levels increased in the blood, the kidneys are required to filter out the excess ions more often, which can lead to a greater incidence of renal stones (Wei-Haas, 2016). Increasing the level of physical activity and allowing bones and muscles to be worked similarly to Earth can ensure these effects are less impactful, especially when astronauts return to Earth.

In terms of atmospheric differences, Mars’ atmosphere about 100 times thinner than Earth’s (Klotz, 2017) with an atmospheric pressure roughly at 600Pa (Pascals) compared to Earth’s average at 101,300Pa which can cause the blood to boil in our bodies (Coffey, 2008), even at ambient temperatures. Another difference is within the composition of the atmospheres. On Earth, our atmosphere is composed of about 78% nitrogen, 21% oxygen and trace levels of other gases, water and carbon dioxide. Mars in comparison has a 95% carbon dioxide atmosphere. As a key need for survival is oxygen, the lack of free oxygen in the Martian atmosphere makes it impossible to breathe. These factors alone inhibits human survival without aid when exposed to the environment (Tate, 2015).

Further difficulties include the freezing temperatures, toxic dust and radiation on the planet’s surface (Klotz, 2017). Ambient temperatures on the planet are about -55oC, being the hottest at 20oC at equatorial regions and a chilling -150oC at extremities. Like Earth, Mars has seasonal changes meaning that temperatures can vary throughout the year, proving another challenge that requires suitable equipment to keep astronauts properly warmed (Purcell, 2016). Despite this, temperatures on Mars are not as regulated as that on Earth. This is due to the fact that Earth’s temperatures are stabalised by the geo-chemical carbon cycle, requiring mainly carbon dioxide and water, carrying greenhouse gases into the atmosphere to radiate heat (Kasting and Walker, n.d.). Mars’ atmosphere, despite being composed mainly of carbon dioxide doesn't have enough as the atmosphere is so thin (AmbretteOrrisey, 2018). It also doesn’t lacks a reliable source of liquid water to be used in the cycle (Johnson, n.d.).

In addition to probability of temperature fluctuations as a result of Mars’ thin atmosphere, strong winds are often likely to develop leading to dense dust storms that can impact the amount of solar power available (Purcell, 2016). Mars being further away from the Sun than Earth already has a shorter day span (Tate, 2015). These complications are currently one of the biggest obstacles to human exploration on the surface of Mars as the storms can block out the Sun and thus further decrease temperatures (Purcell, 2016).

Moreover, Mars is subject to a higher level of radiation compared to Earth. Solar flares, an intense burst of radiation sending electromagnetic charges at high speeds, are often discharged from the Sun (NASA, 2015). Earth isn’t subject to the same level of radiation from the bombardment of charged particles from the Sun due to the presence of the magnetic field that deflects the particles. Mars however lacks a global magnetic field which in addition to it’s already thin atmosphere subjects the planet to a higher level of radiation.

The combination of the above reflect the need for technology able to sustain human health in the harsh environment over a prolonged period of time for a successful mission. Astronauts require suits protecting them from radiation, carry oxygen tanks when exploring the Martian environment and be stationed near the equator to ensure the warmest ambient temperatures, limiting the need to adapt equipment to sustain them under harsher conditions.

Another consideration would be a reliable source of food. Ideally, being able to grow food on Mars allows astronauts to bring less on present and future missions. Mars essentially has most of the requirements for photosynthesis to occur; an abundance of sunlight and carbon dioxide, suitable heat near the equator and water that can be extracted. However, unlike Earth’s soil which is rich with nutrients, Mars’ soil contains high levels of perchlorates toxic to organic material (Purcell, 2016). There is hence a need for more research on Mars, creating better solutions to this issue other than shipping Earth soil to the planet.

The challenging nature of surviving on Mars due to the above conditions are the major obstacles to a successful manned mission to Mars as of now. Other than that, there are many plans on how NASA could land a crewed mission to Mars. One in particular suggests landing astronauts on one of Mars’ moons, Phobos or Deimos, before actually landing on the Red Planet. The process would require launches from NASA’s Space Launch System (SLS) capable of sending crew, cargo and spacecraft like the Orion capsule to Phobos for the first half on the mission. Crew would then be transferred to Mars and stay in a lander containing suitable shelter and an ascent vehicle to enable the trip back to Earth. This procedure is thought to be able to reduce the risks and costs, making them more manageable but isn’t an official plan from NASA (Wall, 2015).

Benefits and Drawbacks: Human vs. Robotic Exploration

Curiosity of the unknown is a key feature of humans which spurred the desire to explore space, despite it being a hostile environment completely unsuitable for survival of life. As a result, multiple technological advancements have been made in the attempt to explore space, first starting off with unmanned vehicles and eventually progressing to crewed missions. Countless spacecrafts have been launched and landed on celestial bodies since mid-twentieth century, but landings on the Moon have been the farthest that humans have traversed.

Factoring this in, the main benefit of robotic exploration is cost efficiency. Robotic exploration has been a key element in paving the way for human exploration. As the technology sent into space is more ‘disposable’ compared to human life, there are fewer considerations to be made in regards to ensuring the astronaut’s health and safety. Subsequently, many costs can be saved in creating and maintaining equipment that allows human survival in space. As discussed above, there are many factors and considerations in regards to the environment outside of Earth that require alterations or technological aid in order for humans to survive, all of which requiring further costs and are a difficult engineering challenge to overcome. Most importantly, shuttle missions are considerably more expensive to launch compared to robot explorations. Current estimates of shuttle launches average to about $1.3 billion over a lifetime with additional costs per launch conducted (Phys.org, 2005). Although this amount covers developmental costs and modifications for safety, overall costs are extremely expensive with little return. Compared to the wider range of data that unmanned missions can conduct, crewed missions are limited in that aspect as humans require more to function. The basic needs for survival; food, water and air are all lacking in space, requiring sources to be delivered to astronauts or brought along to the trip. There’s also the need for the repair and maintenance of equipment sustaining the temporary habitat of astronauts (Phys.org, 2005).

In relation to missions on Mars, there have been many successes like the Mars Pathfinder and Exploration Rovers that explored the surface of Mars and delivered valuable evidence like the presence of water on Mars and proof of conditions suitable for microbial life (NASA, n.d.).

However there can be an argument made for human exploration. Despite robots being able to traverse much further and in more hostile conditions than humans, the lack of flexibility in each mission limits the ability to widen the scope of missions. As discussed above, robotic explorations are often much cheaper than crewed missions. One of the contributing factors is due to the minimalistic nature of its design. Robots are made for specific missions to gather desired data (Phys.org, 2005). Essentially it is coded to perform in a certain way but cannot act outside of that and therefore lacks the spontaneity that humans are capable of if follow up data is desired. It cannot react to any information gathered and require human input to conduct further studies. The ability to essentially think and process information spontaneously allows the focus of missions to be narrowed down according to data required rather than mindless, unproductive study of the environment.

In relation to Mars missions; out of the 31 missions conducted by countries across the globe, only five were able to meet the original objectives (Phys.org, 2005). Crewed missions, being more meticulously planned out and having the additional factor of human adaptability, tend to have a higher success rate at about 90% and are therefore more effective in that aspect.

Conclusion

As of the capabilities of today’s technology, it is essentially more feasible for robotic exploration over crewed missions. Robotic exploration will always be necessary to gain a better understanding of space before humans explore it. In comparing costs, success rates and our increasing understanding of space it is crucial that future missions involve both crewed and robotic exploration to collect and study data gathered effectively. Factoring in advances in science and engineering, it is possible for feasible technology to be developed to overcome the obstacles currently preventing effective and efficient crewed missions.