Yes, I think surely it will! Apart from anything else, if you try to send humans to the Mars surface, then the actual landing on the surface is probably the riskiest part of the journey. Some non zero chance that you get a crash landing.
After a crash with a human occupied spacecraft - you get human bodies, and soil, and food, and atmosphere spread around on the surface of Mars. Then microbes can get imbedded in a grain of sand, which protects them from UV light, and in the Mars dust storms, which can cover the whole planet and sometimes last for months, and at their thickest, block out 99.9% of the sunlight - can be spread anywhere on Mars.
With the landers and rovers they try to get it down to at most 300,000 cultivable spores over the entire craft before launch and 300 spores per square meter (possibly 100 times that number of non cultivable archaea). People who quote that figure often forget it is about the count before launch from Earth. And though it may sound a lot, is not a lot for microbes.
The idea is that the journey to Mars reduces it further, also the landing, and then when they get there, that the lander lands somewhere where life is unlikely. And any remaining microbes will be stuck in cracks in the rover, hidden away from UV light, etc, most likely dormant, and of the ones that do make it to Mars, most will be ones unable to survive on Mars even if they find suitable habitats.
It can't be a sure thing, is always a matter of probability. But the original aim was that we should have a less than 1 in 1,000 chance of contaminating Mars in the exploration phase (based on 1 in 10,000 of contamination per mission flown and around 60 missions). Planetary protection
Due to various mishaps, the chance we have done it may be more than that but on the other hand, Mars turned out in many ways more hostile to life than expected, so there is a reasonable chance we haven't contaminated it yet.
With humans on Mars you have hundreds of trillions of microbes in tens of thousands of species for each human. And more in the food and the soil. And all of those could get scattered over the surface in event of a hard landing.
It is still a probability thing, but with numbers like that, this surely hugely increases chances of contaminating Mars.
As for spacesuits, they are not designed as bio protection suits. They leak air all the time (many don't know that), hundreds of litres of air. And every time you open an airlock, air escapes. And do you think they will keep all the human wastes inside the spacehips indefinitely? And what if some hazardous chemical builds up in the atmosphere - priority is always human lives and health - they would just let it out into the Mars atmosphere.
Can't imagine any attempt at containing the microbes inside Mars habitats lasting for long. But the hard landing thing makes the whole issue a moot point anyway as how can the landing be made safe for planetary protection?
COSPAR meets for workshops from time to time to discuss this, like every few years - what are the requirements that need to be followed when sending humans to the surface of Mars for planetary protection. And they always end their workshop reports with "more information needed". But - I don't see how they are going to find a solution to this myself. Not with present day technology.
As for the possibility of extremophiles in a spacecraft - well they have found extremophiles in the human belly button, and on the tongue, and in our clothes. And tests of surfaces in spacecraft assembly clean rooms always turn up numerous species of extremophile. They are everywhere. Because a microbe that has extremophile capabilities often doesn't lose those capabilities when it lives somewhere more hospitable. And the clean rooms select for microbes able to survive all the methods used to attempt to keep them sterile.
And that's just the ones we can identify. 99% of all microbes can't be cultivated in typical samples. Many DNA fragments in the test samples belong to unknown species of archaea. That means we don't know their capabilities, how they live, or what they do.
As for habitats on the surface of Mars, the most recent experiments by Nilton Renno's team showed that droplets of water can form on ice / salt interfaces rather easily.
It's also possible for life to survive without any water at all. For instance in the Atacama desert, microbes living in salt pillars, they get moisture from the micropores in the salt pillars even with humidity well below 100%. And the DLR experiments with lichens and microbes in Mars analogue conditions suggest that at least some Earth lifeforms may be able to survive on the surface of Mars almost anywhere just using the night time humidity of the air. That's on going experiments - so - they haven't yet done really long duration ones and the lichens and cyanobacteria would be growing slowly but they do metabolize and photosynthesize in a simulated Mars chamber duplicating many of the conditions on Mars. Certainly can't rule it out yet.
None of this proves that there are habitats for life on Mars. Or that humans would contaminate Mars. But there is a strong possibility for both.
Given the amazing discoveries that could come from studying a pristine Mars, I don't see how the COSPAR reports can give it the go-ahead until you can actually prove that it is safe. Until then surely they will just keep returning "more information needed" in the conclusions of their reports.
I think those who want to colonize Mars are over optimistic that somehow their plans will be proved to be okay by planetary protection. Either that or that the exploration phase will be completed. But they have extended the duration of the exploration phase, recognizing that there is no chance we will have explored a significant part of Mars on the ground, searching for life, in the next few decades. I think myself, the way things are going, there is no chance that e.g. by the 2020s we can say we have explored Mars adequately enough to say that the exploration phase is over, that we know all that we need to know about presence of life on the surface. I'd be surprised if we have sent a rover, by then, even to just one example each of all the suggested types of habitats where life may occur on or near the surface, never mind explored them thoroughly.
Myself - though it would be kind of cool to see humans on Mars, mainly because of all the sci. fi stories about it - it wouldn't be cool to contaminate Mars with Earth microbes - and ruin it for all time. If we contaminate it now, then for thousands, even millions of years in the future, nobody gets to study pristine Mars because of those stupid C21 humans who contaminated it with Earth life just to say that they were the first to put their boots on the surface of Mars. It is at least possible that that is how it would be remembered.
So, maybe we need another type of science fiction story.
The safe way to explore Mars with humans is by telepresence, from orbit or from Earth. With avatars on the surface. Safe for planetary protection, also safe for the humans too as they don't run all the risks of the landing, and if they have an accident on the surface, it's only their avatar that is damaged, many other benefits of that approach.
Or we can just continue with better and better and more and more autonomous rovers.
That is until we understand Mars better - or until we develop some amazing future technology that lets us land humans on the surface of Mars without contaminating it.
See Robert Walker's answer to Since it takes between 3-22 minutes to send a message to Mars, we can't control surface robots in real time. What about having humans in (Mars) orbit control robots on the surface?
After a crash with a human occupied spacecraft - you get human bodies, and soil, and food, and atmosphere spread around on the surface of Mars. Then microbes can get imbedded in a grain of sand, which protects them from UV light, and in the Mars dust storms, which can cover the whole planet and sometimes last for months, and at their thickest, block out 99.9% of the sunlight - can be spread anywhere on Mars.
With the landers and rovers they try to get it down to at most 300,000 cultivable spores over the entire craft before launch and 300 spores per square meter (possibly 100 times that number of non cultivable archaea). People who quote that figure often forget it is about the count before launch from Earth. And though it may sound a lot, is not a lot for microbes.
The idea is that the journey to Mars reduces it further, also the landing, and then when they get there, that the lander lands somewhere where life is unlikely. And any remaining microbes will be stuck in cracks in the rover, hidden away from UV light, etc, most likely dormant, and of the ones that do make it to Mars, most will be ones unable to survive on Mars even if they find suitable habitats.
It can't be a sure thing, is always a matter of probability. But the original aim was that we should have a less than 1 in 1,000 chance of contaminating Mars in the exploration phase (based on 1 in 10,000 of contamination per mission flown and around 60 missions). Planetary protection
Due to various mishaps, the chance we have done it may be more than that but on the other hand, Mars turned out in many ways more hostile to life than expected, so there is a reasonable chance we haven't contaminated it yet.
With humans on Mars you have hundreds of trillions of microbes in tens of thousands of species for each human. And more in the food and the soil. And all of those could get scattered over the surface in event of a hard landing.
It is still a probability thing, but with numbers like that, this surely hugely increases chances of contaminating Mars.
As for spacesuits, they are not designed as bio protection suits. They leak air all the time (many don't know that), hundreds of litres of air. And every time you open an airlock, air escapes. And do you think they will keep all the human wastes inside the spacehips indefinitely? And what if some hazardous chemical builds up in the atmosphere - priority is always human lives and health - they would just let it out into the Mars atmosphere.
Can't imagine any attempt at containing the microbes inside Mars habitats lasting for long. But the hard landing thing makes the whole issue a moot point anyway as how can the landing be made safe for planetary protection?
COSPAR meets for workshops from time to time to discuss this, like every few years - what are the requirements that need to be followed when sending humans to the surface of Mars for planetary protection. And they always end their workshop reports with "more information needed". But - I don't see how they are going to find a solution to this myself. Not with present day technology.
As for the possibility of extremophiles in a spacecraft - well they have found extremophiles in the human belly button, and on the tongue, and in our clothes. And tests of surfaces in spacecraft assembly clean rooms always turn up numerous species of extremophile. They are everywhere. Because a microbe that has extremophile capabilities often doesn't lose those capabilities when it lives somewhere more hospitable. And the clean rooms select for microbes able to survive all the methods used to attempt to keep them sterile.
And that's just the ones we can identify. 99% of all microbes can't be cultivated in typical samples. Many DNA fragments in the test samples belong to unknown species of archaea. That means we don't know their capabilities, how they live, or what they do.
As for habitats on the surface of Mars, the most recent experiments by Nilton Renno's team showed that droplets of water can form on ice / salt interfaces rather easily.
It's also possible for life to survive without any water at all. For instance in the Atacama desert, microbes living in salt pillars, they get moisture from the micropores in the salt pillars even with humidity well below 100%. And the DLR experiments with lichens and microbes in Mars analogue conditions suggest that at least some Earth lifeforms may be able to survive on the surface of Mars almost anywhere just using the night time humidity of the air. That's on going experiments - so - they haven't yet done really long duration ones and the lichens and cyanobacteria would be growing slowly but they do metabolize and photosynthesize in a simulated Mars chamber duplicating many of the conditions on Mars. Certainly can't rule it out yet.
None of this proves that there are habitats for life on Mars. Or that humans would contaminate Mars. But there is a strong possibility for both.
Given the amazing discoveries that could come from studying a pristine Mars, I don't see how the COSPAR reports can give it the go-ahead until you can actually prove that it is safe. Until then surely they will just keep returning "more information needed" in the conclusions of their reports.
I think those who want to colonize Mars are over optimistic that somehow their plans will be proved to be okay by planetary protection. Either that or that the exploration phase will be completed. But they have extended the duration of the exploration phase, recognizing that there is no chance we will have explored a significant part of Mars on the ground, searching for life, in the next few decades. I think myself, the way things are going, there is no chance that e.g. by the 2020s we can say we have explored Mars adequately enough to say that the exploration phase is over, that we know all that we need to know about presence of life on the surface. I'd be surprised if we have sent a rover, by then, even to just one example each of all the suggested types of habitats where life may occur on or near the surface, never mind explored them thoroughly.
Myself - though it would be kind of cool to see humans on Mars, mainly because of all the sci. fi stories about it - it wouldn't be cool to contaminate Mars with Earth microbes - and ruin it for all time. If we contaminate it now, then for thousands, even millions of years in the future, nobody gets to study pristine Mars because of those stupid C21 humans who contaminated it with Earth life just to say that they were the first to put their boots on the surface of Mars. It is at least possible that that is how it would be remembered.
So, maybe we need another type of science fiction story.
The safe way to explore Mars with humans is by telepresence, from orbit or from Earth. With avatars on the surface. Safe for planetary protection, also safe for the humans too as they don't run all the risks of the landing, and if they have an accident on the surface, it's only their avatar that is damaged, many other benefits of that approach.
Or we can just continue with better and better and more and more autonomous rovers.
That is until we understand Mars better - or until we develop some amazing future technology that lets us land humans on the surface of Mars without contaminating it.
See Robert Walker's answer to Since it takes between 3-22 minutes to send a message to Mars, we can't control surface robots in real time. What about having humans in (Mars) orbit control robots on the surface?
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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