Risk management techniques are used throughout everyday life. Individuals prevent injury and harm by performing different actions such as wearing their seatbelts, supervising their children, and washing their hands. Simple precautions often prevent disastrous outcomes. These same practices may be applied to larger situations in the space exploration industry where many more risks, complex equipment, and critical procedures come into play. It is important for human factors engineers (HFE) to cooperate when planning a mission to space in order to identify potential problems and their sources, prioritize risk factors, and come up with solutions. Additionally, with humanity’s first excursion to Mars approaching, it is crucial to ensure the safety of the crew through risk management.

There are a multitude of different problems and risks to be aware of during mission planning to Mars. Such risks include radiation exposure, Martian regolith toxicity, and crew member injury. However, it is also important to identify the probability of risk and the impact to crew members and prioritize actions needed to minimize risk. In order to determine priorities, HFEs use an impact versus probability matrix (shown in Figure 1). This tool is designed to assign each risk with rankings in both impact and probability on a scale of 0 to 5. For impact, 5 is valued with the highest risk while 0 represents the least. Similarly, a 5 assigned to the probability of a situation’s occurrence signifies a problem that is very likely to happen while 0 means it is very unlikely to happen. When using the risk matrix to plot a risk, priority can be determined by identifying whether it has been plotted in a low, medium, or high region.

Figure 1

Impact Versus Probability Matrix

Note. This image was found on the Montana Aerospace Scholars Course Website

Many sources of risk exist in a mission. Human risks include the actions and decisions of individuals or groups. In the case of a Martian mission, human risks would refer to actions of the crew members and mission controllers on Earth. When financial resources are lost on an investment, it is known as a financial risk. If a mission fails to meet its objectives, it would result in a financial loss as the return was minimal to none at all unless a useful lesson was learned that could be used to prevent future loss. Other risks include technical and structural risks, which can be found in the design and performance of certain structures and mechanisms when they do not meet the requirements, expectations, or standards. Next, political risks may be incurred with disapproval from decisions, economic instability, and other issues. Operational and procedural risks can appear as certain systems, measures, or strategies do not work as expected or fail to serve their purpose. Finally, project-specific risks are uncertain events that may happen during the course of a project which may increase expected time or affect the overall outcome.

High levels of radiation exposure to astronauts is a risk to human health that is naturally caused by the Sun. Exposure to radiation can cause problems in astronauts such as the development of cancer, damage of cells, and the appearance of reproductive problems. Unlike Earth, Mars does not have a suitable magnetic field or atmosphere to protect life from radiation exposure. Therefore, it is crucial for teams on Earth to ensure the protection of astronauts by setting up precautions limiting and preventing the crew’s exposure. Considering the health problem hazards and prevalence of radiation on Mars, the impact and probability of exposure may both be valued at a 5. This places this risk in a region of high prioritization.

Another risk is contamination by Martian regolith. The soil on Mars is known to be abrasive, adhesive, and damaging — both to humans and technology (The European Space Agency, n.d.). This potentially dangerous soil is naturally present on the surface of Mars. Dust ultimately rendered the Spirit and InSight missions inoperable due to the accumulation on solar panels which lead to insufficient charge to maintain sufficient power. Regolith may also scratch and damage different instruments as well as mechanical components such as wheels and motors. When astronauts venture outside, they may track harmful dust back into the base which may damage instruments and systemic components on the inside. Additionally, inhalation of Martian dust may cause damage to lung tissue and be toxic as they contain strong oxidants and perchlorates (NASA, 2010). It may be determined that the impact of this risk to be a 4.5, medium-high, due to the health, safety, and technical hazards with the probability of an occurrence to be a 5, high. The impact versus probability matrix reveals this risk to be in a region of high priority when plotted.

An additional risk is the injury of a crew member. Injuries may be caused by many different scenarios, whether that be a human mistake, a natural incident, a procedural error, or a failure of an operational, technical, or structural component. Scientists with NASA in the Human Research Program Investigators’ Workshop identified that the probability for nominal injuries are 4.8% for minor, 1.0% for moderate, 0.27% for severe, and 0.03% for life-threatening. Contrarily, probabilities for off-nominal injuries are 19.1% for minor, 3.9% for moderate, 1.1% for severe, and 0.11% for life-threatening (Somers et al., n.d.). As these situations are unlikely yet still possible to happen, the Mars human factors team has assigned the probability a value of 2, meaning low to medium. An impact relies on the severity of an injury. A minor injury such as a bruise may heal quickly. However, a severe injury may affect an astronaut’s performance and a life-threatening injury can impact the crew’s mental health. It may also require a mission back to Earth, which would cost both time and money. The victim also may not be able to make it to proper treatment in time. However, this would likely not happen, and the impact of an injury may be assigned with the value of 4, which means medium to high. When plotted on the impact versus probability matrix, the risk is determined to be in the medium region of priority.

After determining different risks and their sources, it is important to find ways to mitigate the problems and identify what levels of risk are acceptable. When looking at the problem of radiation exposure, which comes first on the priority list with the most significant value in the high risk area, there are many potential solutions. One method would be to increase the amount of materials in order to help shield crew from dangerous energetic particles. Material volume alone can help cut down on the amount of radiation by absorbing these particles before its contact with the astronauts. However, a problem arises with this solution as it takes more fuel to launch this additional mass and therefore would be more expensive. Though it would be difficult to launch more mass to Mars, there are other volume-increasing solutions available on the planet itself. Researchers have determined that covering a base with 1 to 2 meters of Martian regolith may limit radiation (Zhang et al., 2022). Another strategy to decrease exposure would be to use protective materials. Hydrogen is found to be an effective radiation shield (How to, 2015). As water whose molecules are composed of two hydrogen and one oxygen atom is already necessary for living on Mars, water can be strategically stored within the walls of a base. Additionally, trash produced from the astronauts may be turned into tiles which may line the outside of a base. Radiation exposure has become a risk that is accepted due to the fact that all crewed missions to space have had to work with exposures. There is no ultimate solution to this problem but there are ways to prevent harm caused by radiation. In the end, there is a balance between how much protection can be offered and how much radiation can be experienced without astronauts experiencing detrimental levels of radiation exposure. Missions will need to accept certain levels of risk to the health and safety of the crew.

Solutions to Martian regolith contamination, which came second on the priority list with a high risk area, are being researched. To prevent energy shortages, solar panels could be developed to tilt, vibrate, or blow the dust off of its surface. However, the abrasive characteristic of the regolith may still cause scratches that may damage materials. Spacesuits may be designed to stay outside of the base, attaching to the outer wall and allowing an astronaut to climb out of the suit to get inside. This would reduce the risk of tracking any unwanted martian dust into the base. Furthermore, scientists at the Kennedy Space Center are developing electrostatic precipitator systems which efficiently collect small particles throughout a wide range of industrial applications (Scientists, 2017). Missions to Mars will have to accept that Martian dust will exist as an issue which may affect certain systems, technologies, and perhaps even the health of the crew. Mission planners may establish measures to reduce the effects and damage that may be inflicted by the regolith, but with today’s technology the risk cannot be fully eliminated.

Many solutions are available to avoid a crew member injury, which is valued at a medium risk. These include rounding exposed objects, padding helmets properly, attaching warning labels to hazardous objects, insulating exposed electrical conductors, and establishing fire preventative measures (Johnson Space Center, n.d.). Additionally, it is important to provide sources of treatment in the event a crew member is injured. In order to readily treat injuries, astronauts go through first aid training to help either themselves or a crewmate. First aid kits must also be provided. Furthermore, it would be beneficial to provide a medical specialist on long-term missions. In the case of injuries, it is not always known how a crew member may be harmed. However, when a hazard or potential source of injury can be identified it is important to reduce the risk of harm to crew members. It must be accepted that there are chances of injury. Any mission or project including those on Earth involves risk of injury.  However, severe or life-threatening injuries can not be accepted as they affect the outcome of a mission and the spirit of crew members. Nevertheless, all mission planners can do is mitigate such injuries from happening by implementing safety measures.

There will always be risks to crew members in the planning of missions. Problems can not always be avoided, but human factors engineers can set measures to reduce the probability of issues from occurring in order to ensure the safety of astronauts. When mitigating risks, one must first identify the problem and source. The source of a problem may assist in developing prevention strategies and solutions. HFEs must also identify the severity of a risk on the impact vs probability matrix. This can help mission planners prioritize risks by their urgency. It is also crucial to learn from mistakes in order to prevent future errors. As more missions into space are planned there will be a concurrent need for problem solvers (or HFEs) to ensure the success of the mission. Future missions will benefit from reduced risk from technologies developed in the present. However, present day risk mitigation is an ongoing challenge and missions must plan and react accordingly. Similar to precautions individuals take in everyday life, it is important to take precautions in missions, especially crewed ones. Collaboration is crucial to limit risk and thereby greatly increase the probability of mission success. 

References

How to Protect Astronauts from Space Radiation on Mars. (2015, September 13). NASA. Retrieved January 15, 2023, from http://www.nasa.gov/feature/goddard/real-martians-how-to-protect-astronauts-from-space-radiation-on-mars/

Johnson Space Center. (n.d.). Crew Safety. Man-Systems Integration Standards. Retrieved January 15, 2023, from https://msis.jsc.nasa.gov/sections/section06.htm

NASA. (2010, August 2). Toxic Effects of Martian Dust on Humans. Mars Exploration Program Analysis Group. Retrieved January 15, 2023, from https://mepag.jpl.nasa.gov/goal.cfm?goal=5

PM Risk Chart. (n.d.). MAS 2022-23. https://mas.montanalearning.org/mod/assign/view.php?id=2559&action=editsubmission

Scientists Developing Technology to Remove Martian Dust. (2017, June 26). NASA. Retrieved January 15, 2023, from https://www.nasa.gov/feature/kennedy-scientists-developing-technology-to-remove-martian-dust/

Somers, J., Gernhardt, M., & Newby, N. (n.d.). Assessing the Risk of Crew Injury Due to Dynamic Loads during Spaceflight [Slide show]. NASA Technical Reports Server. https://ntrs.nasa.gov/api/citations/20150001872/downloads/20150001872.pdf

The European Space Agency. (n.d.). Dust Contamination Effects and Mitigation for Lunar and Martian Surface Mission. Directorate of Technology, Engineering, and Quality. Retrieved January 15, 2023, from https://technology.esa.int/news/dust-contamination-effects-mitigation-for-lunar-martian-surface-mission

Zhang, J., Guo, J., Dobynde, M. I., Wang, Y., & Wimmer‐Schweingruber, R. F. (2022). From the Top of Martian Olympus to Deep Craters and Beneath: Mars Radiation Environment Under Different Atmospheric and Regolith Depths. Journal of Geophysical Research: Planets, 127(3). https://doi.org/10.1029/2021je007157