Space Is One Big Petri Dish
With return missions to Mars already in the works, it is prudent to develop best practices and protocols to avoid contamination to and from Earth
Given all the efforts invested in finding extraterrestrial life, it makes sense that we would do our utmost to not spread our earthly contaminants to any otherworldly forms of life. As early as 1956, the U.N.’s Committee on the Peaceful Uses of Outer Space (COPUOS), as well as other non-governmental organization, began to propose regulatory measures to deal with contamination and sterilization issues associated with space exploration. The Committee on Space Research (COSPAR) of the International Council for Science (ICSU) has been active for decades in developing these policies.
To this day, COSPAR continues to promote international scientific research in space while preserving “opportunities for the study of life and organic chemical evolution" and avoiding harmful contamination.
COSPAR’s aspirations are non-trivial, especially as they are non-binding and space exploration has become significantly more complicated, multinational, commercial, and budgetarily constrained.
One complication is unanticipated non-normal landings onto other celestial bodies, also known as crashes. For example, SpaceX did not sterilize Starman, the Tesla roadster now hurtling potentially towards Mars. Moreover, there are the hundreds, and soon to be thousands, of cheap and diminutive unsterilized cube satellites that could one day hit another celestial body, bringing with that impact all of the associated hearty earth microbes. Given the huge costs associated with cleaning these devices—estimated to amount to at least 14% of each mission's budget—it is not easy to convince commercial companies to clean their devices, especially given the small probability of a non-normal landing and the lack of binding regulation.
Still, ostensibly every one of the robots and probes that are sent to planets and asteroids would seem to be required by international law to achieve some vague level of decontamination. Specifically, Article IX of the Outer Space Treaty requires space-faring states to conduct exploration of celestial bodies "so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, shall adopt appropriate measures for this purpose.”
While Article IX is limited to governments, Article VI arguably extends such requirements to private organizations as well. Article IX has broad implications: space exploration creates many potential opportunities for contamination, including, outbound and forward contamination, back and return contamination, as well as the possibility of cross-contamination between or among other celestial bodies. This contamination is not necessarily limited to human fabricated or earth-based contaminants. There is also a confounding background baseline level of natural cross contamination throughout the universe due in part to meteorite strikes.
Contamination might occur even under the harshest conditions of space. On the return from the first human journey to the moon, in addition to having infamously gone through the indignity of U.S. Customs, the astronauts were also subjected to a one-month quarantine, just in case. In at least one instance, recovered devices from an earlier mission were found to still have some biocontamination on them, even after years on the moon. Nevertheless, given what we know now regarding the harsh environment of the moon, current sterilization efforts for the lunar missions are very limited. Even those lunar quarantines were eventually discontinued after Apollo 14 in 1971.
At this point, under current NASA rules, neither outward-bound lunar probes nor returning robots from the moon require any sort of pre or post sterilization procedures. The prior discovery of bio-contaminants from the moon notwithstanding, this makes scientific sense—the moon effectively has no atmosphere, it is constantly being bombarded by ultraviolet and other cosmic radiation, and local temperatures fluctuate between around -170 degrees Celsius and 123 degrees Celsius, with temperatures plummeting to as low as -230 degrees Celsius at the poles. Life as we know it would seem to be unable to survive unprotected on the moon, although contaminating terrestrial organic matter might.
However, even if contaminating the moon with life is unlikely, re-introduced efforts to prevent moon contamination might be justifiable as a testing ground for future Mars and other celestial explorations.
Consider the costs and investments that NASA already puts into preventing contamination in space. Currently, Mars probes are cleaned by NASA to such a degree that there are only approximately 300,000 microbes on the surface of the ships. This might seem like a lot, but compare it to you and me: the average human has at least 40 trillion microbes on their exposed surfaces. Another example is the Centaur rocket that was responsible for hurtling the Mars InSight probe to its destination was not cleaned to the same degree as its cargo. To prevent a contaminating non-normal Centaur landing on Mars, the initial trajectory of the launch was purposefully set to miss Mars, so that when the Centaur was eventually separated, it would cruise to infinity, away from Mars.
Still, even with all of this intricate planning and foresight, NASA needs to work harder on its planetary protection methods, and the moon might be just the place to practice. A recent report by the National Academies of Sciences, Engineering, and Medicine has found current planetary protection policies to be woefully inadequate. For example, the Office of Planetary Protection (OPP), whose motto is “protecting all of the planets, all of the time," and whose mission is to formulate, implement, and ensure compliance with contamination policies, is a part of NASA, constituting a major conflict of interest. Also, there is, as of yet, no government agency that has the authority to regulate non-governmental space exploration.
However, things are slowly starting to change for the better. Last year, NASA appointed biochemist and astrobiologist Lisa Pratt as head of the OPP. Pratt has pledged to revise the OPP's problematic policies and to work with private space companies to see how they can better prevent contamination. This comes not a moment too soon: with upcoming return missions to Mars in the works, it is prudent to develop best practices and sample-handling protocols to avoid both forward and reverse contamination to and from Mars with organisms that could pose a health risk to life and the environment, on both planets. After all, nobody wants Mars to smell as bad as the ISS.
Dov Greenbaum, JD PhD, is the director of the Zvi Meitar Institute for Legal Implications of Emerging Technologies and Professor at the Harry Radzyner Law School, both at the Interdisciplinary Center (IDC) Herzliya.