Planetary Protection:

An Outdated Policy?

"Planetary protection is a massive problem for the exploration of Mars."

Robert Zubrin

Please Note: the views, interpretations, and opinions expressed in this post are mine, and do not directly represent those of the scientific community.

October 10, 2017

by S. Alex Martin

This should come as no surprise: there are people who want to put humans are Mars, the Moon, and just about any celestial body we can send rockets to. But as spectacular as those visions seem, there's a roadblock that, at the moment, stands in the way of settling the cosmos.


Article IX of the Outer Space Treaty of 1967.

A clause of Article IX reads: "States Parties to the Treaty shall pursue studies of outer space, including the moon and other celestial bodies, and conduct exploration of them 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."

Simply put, the original Outer Space Treaty was a formal declaration put forth in the United Nations that secured the right of any country on Earth (re: State) to access space. Space, and any celestial body within it, the treaty says, belongs to all of humanity, and should therefore be pursued through peaceable means.

The Moon is not the property of any country, nor is Mars, or the moons of Jupiter, nor Saturn, nor any object that did not originate from Earth. The resources and locations in outer space are free for all to research, benefit from, and, in due time, settle upon.

The formal signing of the original Outer Space Treaty of 1967.

Article IX seems admirable in its declaration. All extraterrestrial research must be done in a manner that avoids the forward contamination of a celestial body, or the reverse contamination of Earth (i.e. return sample missions that could potentially bring back microbes that are harmful to Earth life). But it is exactly this declaration that impedes human exploration in the solar system and beyond, because Article IX gave rise to NASA's Office of Planetary Protection, which has pioneered further restrictions regarding space exploration amid growing concerns of forward and reverse contamination.

To be fair, contamination--in a sense--is a reasonable concern. You don't want to bring back a disease that life on Earth can't defend itself from (re: has no immunity to), and you don't want to destroy ecosystems on other celestial bodies, even microbial ones. This is because discovering life elsewhere in the universe would permanently change how we understand our own existence. In fact, you could argue that finding life beyond Earth will be the most important discovery in all of history -- perhaps the most important discovery any intelligent species could ever make. Therefore, forward and reverse contamination is generally frowned upon in the scientific community, because it would likely be a destructive encounter.

All of this in mind, Article IX of the Outer Space Treaty, paired with Planetary Protection policies, fuels a debate that will one day come to the forefront of space policy. Even now, there are government agencies and private companies developing spacecraft architecture to send humans to the moon, Mars, and asteroids. But with the current policies, restrictions, and treaties in place, only three scenarios could legally play out:


  1. We never leave Earth.

  2. We go to other celestial bodies, but remain in orbit, forever confined to space stations.

  3. We land on celestial bodies, but confine people, experiments, and Earth-originating microbes to an quarantine.

An artist's impression of NASA's Orion spacecraft approaching Mars

Option #1 simply isn't a choice anymore. Unless some cataclysmic natural event occurs, or another world war breaks out in the near future, humans will start flying out to Mars in the next decade or two. SpaceX is leading the charge with the most ambitious plan to land humans in the mid-2020s, NASA hopes to get there in the 2030s (despite admitting it still doesn't have enough funding to do so), and other countries and space agencies are developing their own plans to land humans on the red planet, even the United Arab Emirates, with its plan to establish a colony in the 2100s.

Option #2 is the foundation of NASA's Journey to Mars. Fly people to Mars, but keep them in orbit, running experiments by controlling rovers on the surface and collecting data. It would function in a similar manner to the International Space Station, with crews coming and going once every few years instead of every few months. Although this route may be safer, it relies heavily on old technology, will take at least two full decades to execute, and there is no tangible plan for humans to actually set foot on the planet.

Option #3 is perhaps the best legal chance we have to put humans on Mars under current regulations, but it is also the least likely to occur under said regulations. As Elon Musk's updated Mars infrastructure comes to fruition, there will likely need to be a new treaty written and agreed upon by, perhaps, the United Nations, or the International Astronautical Conference, or even an assembly of the handful of countries that have space programs (as of this writing, Australia recently announced it will be forming its own space agency). Even though as many as 71 countries claim to have space programs, only 13 have the ability to launch objects into orbit, and only three (Russia, United States, and China, in that order) have ever launched humans.

The era of government agencies dominating human spaceflight is coming to a close, however, and this has produced a lot of gray area. Private companies are sprouting up around the world, with several taking aim at putting humans into orbit, on the Moon, and, of course, Mars. The United Launch Alliance (ULA), headed by Tory Bruno, and SpaceX, headed by Elon Musk, will both be launching crewed missions for NASA beginning in 2018 and 2019. SpaceX famously wants to send the Big F***ing Rocket (codename: BFR) to Mars and build a city, now outposts on the Moon, and even travel between cities on Earth. These ambitions will force regulations to be debated and rewritten. It's not a question of if more so than when.

SpaceX wants to build a city on Mars over the course of several decades.

In a commercialized era, we will see amendments to, if not the outright abolition of, many provisions of the Outer Space Treaty and other recognized regulations designed to protect against interplanetary contamination. To sustain humans, we will need extremely reliable habitats, and terraformation will need to begin as quickly as possible. That includes thickening and retaining Mars' atmosphere, which is 1/100th as dense as Earth's, 95.32% carbon-dioxide, and is being stripped away by solar wind -- a consequence of Mars not having a strong magnetic field.

All of these problems need solved, and we can tackle them all at the same time. Plans to generate an artificial magnetic field have been discussed, the most serious coming from NASA itself. We will also need to develop healthy biomes that allow microbes to flourish, nurture samples of soil, and support flora, followed by fauna, all in a controlled setting. These can first be developed in habitats and farms, and slowly introduced to Mars. Genetically-engineered plants resistant to extreme temperatures, radiation, and lack of nutrition may also have a role to play.

The Martian soil has many nutrients needed to support plant life, but fertilizers may need to be added for enrichment.

Contaminating Mars with Earth microbes and bacteria will be essential to maintaining the nutrients needed for plant life. Like many microscopic organisms, both can adapt to extreme and hostile environments, and both multiply very, very quickly. Scaled en masse, they would contribute to the release of greenhouse gases in the Martian soil, a cascading effect that would amplify the thickening of Mars' atmosphere, and its conversion from being toxic to humans (carbon-dioxide rich) to being nitrogen and oxygen rich, just like Earth's.


If you're worried Mars' atmosphere is too laden with carbon-dioxide for humans to ever

breath it, consider this: given enough time, plants will saturate the atmosphere with enough oxygen for humans to breathe. Earth life is so fine-tuned that, as long as there are reciprocating organisms to maintain a balance, and no toxic interference, the atmospheric composition will return to the exact proportions needed to for all the organisms in the system to survive. That means, if we can thicken Mars' atmosphere and heat the planet enough to support plants, they will turn into oxygen-pumping biomachines (we may need to control their CO2 intake at first, as receiving too much CO2 over a prolonged period would be toxic for the plants, just as too much oxygen is toxic to humans.

For all of this to happen, however, requires a different set of regulations, ones that allow for the controlled forward contamination of Mars and other celestial bodies. As it stands, rovers on Mars aren't even allowed near suspected water sources for fear of contamination. Although the reasons are admirable, I still disagree with the decision, and I think such restrictions limit the ability to do science and prepare humans for settling other worlds.


While discovering life beyond Earth in any form will undoubtedly be science's greatest moment, I think spreading Earth life to other worlds takes precedence. If there is life beyond us, we can still observe the billions of other exoplanets that may harbor it, or we might happen upon clear signals from another intelligent species. All we need is one confirmation. Whatever the case, we should concern ourselves with spreading life into the cosmos, not withholding it.

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Alex Martin is the author of six futuristic science-fiction novels. The third book in the Recovery Series, Perihelid, will be published on October 17, 2017. He's also a science communicator, and has given several assemblies at schools, colleges, bookstores, and libraries. The Experience Daliona website is an extension of his books and a representation of his greatest passions.