Protecting Space from Forward Contamination

As humanity has expanded its frontiers of exploration, education, and technology into the arena of deep space, many people have emphasized pressing concerns over the risk of biological contamination, raising both ethical and scientific arguments. Although there are many destinations for space missions, scientists highlight Mars as the most likely candidate for potential life, thus making it extremely vulnerable to forward contamination. Specifically, in 2012, 298 strains of bacteria were identified to have survived sterilization procedures in European Space Agency clean rooms. It is likely that dormant terrestrial microbes may already exist on the Martian surface, although no active contamination has been currently confirmed.

Given this context, Mars offers an interesting case study in the debate over space contamination. This article argues for the importance of protection measures against forward contamination and evaluates current international agreements, with a specific focus on U.S. policies in addressing this growing concern.

How does space contamination occur? Earth-based extremophiles — organisms that can survive extreme conditions — can endure a wide range of environmental stressors, including high/low temperatures, pressures, and pH levels. Often found dwelling in environments like hot springs, deep-sea hydrothermal vents, and Antarctic lakes, these resilient microbes are also able to survive tedious space travel. When introduced into extraterrestrial environments, they may contaminate these areas with organic material unique to Earth.

There are two primary types of microbial contamination in space exploration: backward contamination and forward contamination. Backward contamination refers to the introduction of potentially unknown extraterrestrial organisms into Earth’s environment, which could create serious risks to both humans and vibrant ecosystems. Forward contamination (the focus of this article) refers to the transfer of Earth-based microorganisms to other planetary bodies. On Mars, for example, these terrestrial microbes may attach to dust particles and spread over large distances during sandstorms, extending contamination beyond the immediate original landing site.

As the number of missions to Mars increases, so does the risk of biological contamination. Why is preventing contamination important to humans? Firstly, it protects the scientific integrity of astrobiological research. If extraterrestrial environments become contaminated with Earth-based organisms, it becomes basically impossible to distinguish native life from introduced life, causing future discoveries to become inconclusive. This could lead to humanity’s wasted resources, misleading data, and flawed mission planning, especially regarding where to land, drill, or explore.

Beyond the scientific aspect, ethical considerations also play a significant role. Many argue that as the only known intelligent species capable of interplanetary exploration, humans have a moral responsibility to preserve and respect the natural environments of other vulnerable worlds. Introducing invasive microbes could not only disrupt potential alien ecosystems but also alter them irreversibly or destroy them into extinction.

International legal frameworks exist to protect space from contamination. After the Soviet Union launched Sputnik in 1957 which marked the start of the space age, the International Council of Scientific Unions responded by establishing the Committee on Space Research (COSPAR) in 1958. COSPAR created various guiding principles to prevent biological contamination, including a critical rule: any mission seeking life beyond Earth must ensure that the probability of a single microbe contaminating a potential extraterrestrial habitat does not exceed 1 in 10,000. 

In 1964, COSPAR issued recommendations on the sterilization of space vehicles and probes, such as through heat, radiation, and chemical procedures. These were adopted by the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS), which advised member states to consider planetary protection measures while drafting the Outer Space Treaty.

As a result, both the Soviet and U.S. drafts of the treaty included provisions addressing the harmful contamination of celestial bodies, which were incorporated into Article IX of the 1967 Outer Space Treaty. This article specifically asks for States Parties to conduct exploration of outer space in a manner that avoids harmful contamination, requiring them to take appropriate steps to prevent changing Earth’s environment due to the introduction of extraterrestrial matter. Interestingly, while Article IX emphasizes backward contamination, it lacks explicit information to prevent forward contamination. This could potentially be because returning microbes was viewed as the greater risk at the time.

In addition, Article VI of the Outer Space Treaty holds states responsible for all national space activities, including those carried out by private companies. These activities must receive prior authorization and continuous supervision by the state. Thus, states that have agreed to the Outer Space Treaty are obligated to make sure that all entities under them implement planetary protection procedures during space missions.

The United States, specifically, does not currently have a comprehensive space law that regulates all national space activities under one framework. Instead, it has a fragmented approach, including different laws in distinct sectors such as launch services, telecommunication satellites, and NASA-related activities. While this may seem disorganized at first glance, it does offer various advantages. For example, the separation of authority provides a useful system of checks and balances, which ensures that no single entity has dominant control over all space operations. This allows for specialized agencies to focus on their expertise and run smoothly, contributing to more efficient, informed decision-making in their areas.

NASA, established in 1958 under the National Aeronautics and Space Act, greatly represents expertise in planetary protection. For example, NASA promotes contamination control through various policies, such as its Biological Contamination Control for Outbound and Inbound Planetary Spacecraft policy, which was most recently updated in May 2013. Through this policy, NASA incorporates the COSPAR guidelines for planetary protection and can enforce them with its contractors. This process ensures that even missions involving external collaborators adhere to established international standards. Moreover, NASA’s Office of Planetary Protection, historically staffed by scientists with deep knowledge in biology, signals a strong commitment to maintaining the scientific integrity of planetary exploration. The agency regularly updates its standards and participates in international discussions, reflecting to the common people transparency and a willingness to accept global ideas.

However, this rigid, segmented legal framework also presents numerous challenges. One of the main cons is the lack of clarity when it comes to regulating private space activities, particularly in the area of biological contamination protection. Under the Commercial Space Launch Act of 1984, the U.S. government licenses commercial space launch activities and requires applicants to submit environmental impact assessments. However, these assessments are primarily focused on Earth-based impacts and launch safety, rather than the potential biological contamination of bodies like Mars. This is further highlighted with the Commercial Space Launch Competitiveness Act of 2015, which provides a legal pathway for private entities to mine asteroids or other celestial bodies without requiring them to conduct planetary protection assessments. With the rise of commercial ventures from private companies like SpaceX and Blue Origin, these problems will increase in the new era of space exploration and resource exploitation.

In conclusion, while the United States benefits from expert-led agencies like NASA and a flexible regulatory structure, its fragmented approach creates inconsistencies in fields such as governing private space activities. As the number of Mars missions and commercial operations continues to grow, it will become increasingly crucial to address these missing gaps and protect the galaxy’s precious environments from forward contamination.