Elon Musk is talking about his plans for Mars again, which is no surprise because he set up SpaceX to send humans to Mars. Lockheed Martin also unveiled their design for a rocket to land vertically on Mars much like SpaceX. But is it a good idea to send humans there anyway? In the news stories about these rockets, nobody even questions this. But what if our microbes trash the planet for the search for life.
This is an artist's impression which gives an idea of what the Lockheed Martin spaceship would look like after landing on Mars.
Yes it would be an exciting day when the first human steps on the surface of Mars, and a matter of prestige for those concerned. This is something I have read about since a child, and I would be as excited as anyone. But all that praise and excitement might quickly change to dishonour if we find that they introduced reproducing Earth micro-organisms to Mars.
The first humans to land on Mars - or to crash there - might easily enter the history books as the people who contaminated Mars irreversibly, making it almost impossible for scientists to study it properly. That's a big deal given that our main scientific reason to go to Mars is to search for life there. To dramatize the idea, here are a series of fake newspaper stories in a (hopefully) "alternative future" in which humans accidentally introduce Earth life to Mars, then regret what they did.
(photo shows Artist's impression of a human astronaut on the Mars surface holding Oskar Pernefeldt's proposed International Flag of the Earth )
(Photo is actually of a slope with RSLs from this paper)
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(Photo is of nanobes from "New life form may be a great find of the century" (1999), at one time thought to be relic RNA world life here on Earth)
(Photograph is Hubble's photograph of a Global Mars dust storm from 2001 )
Actually, if the Earth life they found was salt loving haloarchaea, they don't seem to produce spores (archaea generally probably don't). Instead they have other ways of coping with desiccation including dwarfing of the cells, protective capsules and probably forming dormant states. That's why the article says "spores and other dormant states".
The Lascaux cave painting photo is by Prof Saxx.
I created these fake newspaper stories using this online free newspaper generator. I invented the name of the astrobiology mission specialist using this online fake name generator.
This short story describes a mission similar to NASA's plan for safe zones - based on finding Mars life easily (that links to a section in my online book) according to which they would land the humans inside a region which they judge "safe to contaminate" with Earth microbes. Outside of that, not too far away, they'd have a potentially habitable and biologically interesting site for them to explore using sterile rovers, such as one of the sites with Recurring Slope Lineae. So what happens if the party get caught up in a major Mars dust storm, and then the dust carries microbes from their base to the RSL? That's the basis for this story. My first draft of it had a crash of the human occupied ship, as in Why do spacecraft crash so easily on Mars (in the same book), but I removed it to keep the storyline as simple as possible.
Why not let those first steps be taken by a telerobot instead, operated by a human in orbit around Mars? Or by robots operated from Earth?
SPACE SUITS LEAK AND SPACE SHIPS CRASH
Spacesuits leak, and a human astronaut will be spilling microbes from his spacesuit wherever he goes. Microbes capable of surviving in extreme environments get everywhere - a microbe that does fine on a dry granite cliff face in Antarctica may also be just as happy in a tropical pond or on human clothes. Also, worse - there may well be a 50 / 50 chance of a crash killing everyone on board, and at least a significant chance of that, spreading microbes from their air, food, soil, and fragments of humans over the surface of Mars - much as for the Columbia space shuttle crash.
It's far harder to land on Mars than on Earth with its thin atmosphere. Elon Musk himself says that we have to be prepared for crashes with the first humans to Mars. Also the Mars surface is interconnected.
It would be easy to make a "light air-tight anthropomorphic balloon" as James Waldie puts it, but we need to be able to bend our arms and legs at the joints, and designers achieve that with flexible joints. These have tiny gaps between the moving parts, which leak small amounts of air constantly. Wherever they go, they will leave a trail of microbes.
This photograph of Alan Bean during Apollo 12 is often shared as an example of venting from his spacesuit, or perhaps, ice crystals from the ice sublimator. Actually, Kip Teague, author of the Project Apollo Archive is cited by NASA as saying that it's a smudge on the camera. It was blue when the central subject in the camera was bright and red in tint when it was dark. It was present in the photos from frames 6813 through to 6853 (this photograph is frame 6826).
The venting from the spacesuits wasn't so visible, but they did vent liters of air constantly on every EVA, as do the modern EMU units used for spacewalks on the ISS. If we use similarly gas pressurized spacesuits for Mars, then one estimate is that over 50 litres of human borne bacteria and other airborne effluent would escape through suit bearings and joints during each EVA, potentially contaminating soil, fossil and atmospheric sample" See this paper. Perhaps this can be reduced by measures such as using counterpressure spacesuits on the body pressurized in equilibrium with the Mars atmosphere with only the regions around the head pressurized to full pressure. Still, the experts say that some leakage is inevitable.
One of NASA's identified knowledge gaps for human EVA's on Mars is the amount of microbial leakage from their suits. But they say that some leakage from the spacesuits is inevitable. They also need to vent waste gases from inside the habitat from time to time. Also astronauts' bases and rovers would leak Earth microbes into the dust, every time they open an airlock. The experts say that if we have humans on Mars, then it is inevitable that we contaminate the landing site with Earth life. There is no way to design airlocks, EVA suits etc to prevent this altogether, at present.
Also, the ground they walk on is covered with a fine dust, as fine as cigarette ash, light and easily moved, even in the near vacuum winds of the Mars atmosphere. This fine dust can travel hundreds of kilometers in a few hours during the fast winds of the Mars dust storms. Every decade or so, these storms combine and spread to cover the entire planet, and then can last for weeks. These global dust storms block out the sun and turn day into night, and it takes months for all the thick clouds of dust to settle back out of the atmosphere.
Cover from Andy Weir's "The Martian" to illustrate the fast winds of the Martian dust storms. He uses a dust storm as a central plot point. He knew that in the thin vacuum of the Mars atmosphere, the winds, though fast, are also feeble. So that's a bit of poetic license on his part; they couldn't blow over an astronaut. Indeed you would probably not even feel them. But the winds are very fast, reaching up to sixty miles per hour in dust storms, and even faster in the tiny dust devils. They also do pick up the dust, forming dust clouds, exactly as in the illustration. The winds couldn't pick up most of the dust as we know it on Earth, but they can do that on Mars because the dust is so fine, as fine as cigarette ash. Indeed, they pick up so much dust that the dust storms block out the sun, turning day into night, sometimes for weeks on end. Potentially they could transport desiccation resistant dormant microbes and spores over distances of hundreds of miles a day, and throughout the planet. And all this time, much of the dust will be protected from the harsh UV rays of the sun.
NASA have this as one of their many knowledge gaps for human extraterrestrial missions to Mars: "Obviously, the current understanding of microbe survival in Mars dust environments remains uncertain and represents an important knowledge gap" (page 34 of this report).
Carl Sagan once remarked, that the iron oxides that make up these dust particles are perfect to shield a microbe from the sterilizing UV light of the unfiltered sun. Such a microbe, imbedded in a minute crack in a fine dust grain, could eventually fall to the surface undamaged by the harsh UV light, thousands of kilometers from its point of origin. After a human landing on Mars, billions of hardy microbial spores and desiccated microbes in other dormant states will stream out from their base and spread in the dust and winds. If there are any Mars habitats for them to find, some of them surely have a chance to get there eventually. For more on this see the section: How could this work on Mars with dust storms and a globally connected environment? (in my online book "Touch Mars?").
Also, what is a mission with humans in harsh difficult conditions for months on end going to do about trash? The ISS would generate many tons of trash every year, if it wasn't all burnt up in our atmosphere. See Trash, on the Moon (in "Touch Mars?") . And what if someone dies when they are on the surface? Cremate the body?
So far, you might wonder if it is possible to contain our microbes somehow. They do exactly that with rover computers, which can't be totally sterilized either at present. They enclose the core box and some sensitive electronics with high efficiency filters (like HEPA filters) to keep even particles as small as microbes inside. Could we somehow do something similar for humans on Mars? Keep everything humans touch inside of giant filters to keep the microbes away from the surface of Mars? Could we perhaps somehow include filters in the design of our astronauts spacesuits, in every joint, and vent the spaceships and airlocks etc through such filters? And recycle everything with no trash or waste gases, everything is contained? It might be hugely challenging - but it is possible?
Well, so far the answer seems to be no. The experts say that they would design the missions and equipment to limit the contamination as much as they could, but that it it doesn't seem possible to keep our microbes totally within impermeable barriers when astronauts are exploring another planet. As Rick Davis put it in a press conference,
“We’re basically, if you will, big sacks of microbes. And so keeping that segregated from the Martian environment when humans get there is probably impossible.”
However, this reaches a whole new level of challenge once you start to think about the possibility of an "off nominal" mission. Suppose that instead of a safe landing, they crash on Mars killing everyone on board? After all, the space shuttles Columbia and Challenger crashed, and the landing on Mars is particularly challenging. It's far harder to land there than on Earth, and even with the best efforts to make it safe, a crash of an early crewed mission to Mars has to be fairly high in probability. I cover this in Why do spacecraft crash so easily on Mars? (in my online book) .
Elon Musk warns that early settlers must be prepared to die in the attempt. After a crash like that, minute fragments of the astronauts bodies, food, air, water and the spacecraft itself would spread in the dust, infused with trillions of microbes, and this is likely to irreversibly contaminate Mars with Earth life. The space shuttle debris fields spanned hundreds of miles
Columbia disaster debris field in East Texas - it spans about 250 miles
With Elon Musk's supersonic retropropulsion, the rockets come in at great speed. They don't have parachutes but just use their rockets fired in reverse, assisted with atmospheric resistance, to land vertically on the surface of Mars. His plan is to use the same technology they use to lands the Falcon 9 first stages on a barge in the sea, to land on Mars. On Mars, as with his experiments with the barge landings on Earth, they can come in too hard, and topple over. But there's an additional hazard on Mars. The astronauts' spacecraft has to skim really close to the surface to get enough resistance from the atmosphere to slow down enough to land.
They skim so close to the surface that they can't land on the higher mountains and the Martian highlands, because the air up there would be to thin for this technique. When he says that early settlers have to be prepared to risk their lives, he is not exaggerating. Perhaps the NASA mission might be less risky, it's hard to say, especially since they have no detailed designs yet for their landing craft, but any human landing on Mars is bound to be dangerous. When Curiosity landed on Mars, they didn't call it "Seven minutes of terror" for nothing.
However small or large the debris field is after a crash like that (do say if you know of a way to estimate its size for Mars), the remains would get mixed up in the dust, and perhaps it doesn't make that much difference. The Mars dust storms would surely, in time, spread the finer particles and microbe spores from it throughout Mars. For more on this, see the sections below: How could this work on Mars with dust storms and a globally connected environment? , Why do spacecraft crash so easily on Mars, and Elon Musk's fun but dangerous trip to Mars.
Could we design spacecraft in the near future so that even in a crash on Mars, they will contain all the microbes in a human occupied spacecraft? For some ideas, see Could we send humans to the Mars surface in a biologically reversible way? (in "Touch Mars?") . At any rate we don't have any realistic near future spacecraft that can do this.
WHAT ABOUT ALL THE REASONS FOR SENDING HUMANS TO MARS?
So what about this idea that we have to send humans to Mars with great urgency, because Earth is doomed, some time in the next few centuries / millennia and that we must have humans on at least two planets in order to survive the catastrophes that are bound to follow. At least that's what the likes of Elon Musk and Stephen Hawking suggest. If you think that way, you might feel that it is a matter of such urgency that we don't have time to stop and try to find out if there is life on Mars or what there is there.
Also, doesn't Mars look so like Earth in the photos -- much like deserts in the American West?
The Mars Desert Research Station in Utah - isn't Mars much like this, just a desert like the American Wild West but on another planet?
It even has a day about the same length of Earth's. Does that not mean it's the perfect place to send humans? Ripe for colonization?
Does anyone have the right to stop humans from colonizing Mars? And are we not nature's only way to get to other planets? Are humans not an unstoppable force of nature that shouldn't be thwarted in any way at all?
And what about its thin carbon dioxide atmosphere? Isn't that a huge advantage over everywhere else? The Moon has no atmosphere.
And what about the frontier spirit? Wouldn't humans on Mars, faced with such adversity, be so inventive they could overcome anything, no matter how difficult? Surely we rise to adversity and need difficult conditions to prove what we are capable of?
Also, not only that, wouldn't the humans on Mars with this indomitable "frontier spirit", create a new civilization there which is so inventive that it will be able to survive just through the export of its many inventions to the less challenged and so less inventive Earth? Faced with such an inventive society - what does it matter that you need million dollar spacesuits just to get outside your habitat? What does it matter that you can't breathe a single breath on the Mars surface without a full body pressurized spacesuit? What does it matter that nothing from Earth could grow there except, just possibly, a few lichens and microbes huddled in shadows or beneath the surface and in the rocks? Human ingenuity will overcome all adversity. And the inventions they will have to make on Mars will be so valuable and so revolutionary that they will earn all the billions and even trillions of dollars they need by selling the intellectual property rights for their inventions to Earth! At least that's what the enthusiasts say.
And what about Robert Zubrin's argument that microbes from Earth on Mars can't cause any harm there? We have meteorites going back and forth between the two planets, so it can't possibly do any harm to introduce Earth life to Mars (so they say again).
Well, that's what the Mars colonization enthusiasts will tell you. All those things are part of the argument for Mars colonization that's been built up over many books and articles.
It's going to take a while to answer all these points. There's a whole story been built up around future Mars colonization, but it's based on many assumptions, and just about every single one can be challenged.
ASSUMPTION OF MARS AS LIKE A PROMISED LAND
You have to assume that Mars is almost like a "promised land" designed for humans, to be so optimistic as to think everything will break in our favour like that. There is no guarantee that Mars is even safe for humans, as we'll see. It's certainly not an easy place to live.
That 24 hour day is about the only resemblance to Earth. And it's actually a disadvantage, not an advantage. It means no solar power at night. The thin carbon dioxide atmosphere is a liability because every decade or so, sometimes several times per decade, it blows the thin cigarette consistency ash that covers the planet into global dust storms that block out the sun for weeks on end. That fine dust in turn is riddled with chemicals - perchlorates that harm humans long term, and probably also chlorates and chlorites that are hazardous for us short term too, can even cause vomiting and unconsciousness. We also don't know that Mars life is safe for humans, in the case where there is life there. There's the possibility that it is defeated by our unusual biochemistry, but it's also possible that our defense systems, adjusted for Earth life, are totally naive and let them do whatever they want to us. The Nobel prize winning microbial geneticist Joshua Lederberg put it like this:
"If Martian microorganisms ever make it here, will they be totally mystified and defeated by terrestrial metabolism, perhaps even before they challenge immune defenses? Or will they have a field day in light of our own total naivete in dealing with their “aggressins”?
And though the Mars colonization enthusiasts tend to hit the headlines, there are plenty of scientists that criticize them, on many levels. But this narrative of overcoming the "wild west" of Mars and starting up a new colony there is very powerful in the US especially. This gives a publicity bias. Those who criticize it, they don't tend to get heard much. The articles about their ideas are less interesting to the Mars colonization enthusiasts. If you have an article saying that
"Everything will be fine, Mars is great for humans, microbes from Earth can't do any harm there"
That will be shared far and wide. But an article that suggests that
"Everything won't be fine, humans can trash Mars, Mars is not necessarily a good place for humans"
Well who will share that article? Well I've tried to redress this a bit with my posts.
I think the key is to not just talk about the negatives of humans on Mars but talk about the positives of humans on the Moon. There's actually a lot of support for humans returning to the Moon and many people who say it makes far more sense in the near term. This then takes off some of the pressure that we have to send humans to Mars as soon as possible. What if we don't?
Maybe that can help to make this article more "shareable"?
CHRIS HADFIELD'S ANALOGY OF CANOES PADDLING IN THE SEINE
What happens if you just look in this other direction, of a future where we don't rush humans to Mars as quickly as we can? Maybe it's not such a bad future as you'd think. Astronauts like Chris Hadfield and even Buzz Aldrin who is dead keen on humans on Mars are agreed that it is good to return to the Moon first. Buzz Aldrin was quoted out of context by Obama with his "Been there done that". It was meant as a joke. Buzz Aldrin as with most astronauts, and many scientists, and every government except the US and every space agency except SpaceX, agree that it is good to return to the Moon first.
The retired Canadian astronaut Chris Hadfield, former commander of the ISS, interviewed by New Scientist, put it like this in their article "We should live on the moon before a trip to Mars"
"I think ultimately we’ll be living on the moon for a generation before we get to Mars. If the world and the moon were threatened and the only way to preserve our species was to launch from Earth, we could go to Mars with yesterday’s technology, but we would probably kill just about everybody on the way."
"It’s as if you and I were in Paris, paddling around in the Seine in little canoes saying, 'We’ve got boats, we’ve got paddles, let’s go to Australia!' Australia? We can barely cross the English Channel. We’re sort of in that boat in space exploration right now. A journey to Mars is conceivable but it’s still a lot further away than most people think."
The Moon is not only safer, it's also a natural place to begin to develop reliable technology for multi-year missions throughout the solar system. If we can achieve that then the cost of human missions to the Moon will go down dramatically to a fraction of the normal cost. Imagine what a cost saving it would be if we could send a crew to the Moon for two years with no resupply from Earth, as if it was an interplanetary mission to Mars?
We need these shake out cruises close to Earth first. The Moon or the L1 or L2 positions are ideal places to do them, close to Earth, and also of great interest in their own right. Once we have biological closed systems working on the Moon, then missions throughout our solar system that last for a decade or more could be as easy to support as ones that last for a couple of years or less.
Once we have that capability, we can go to Venus, Mars and beyond, even to Mercury, the asteroids and Jupiter's Callisto, with no worry about narrow safety margins. Or for earlier missions, using ISS type life support to get to Mars or Venus, then we could do shake down cruises in the Earth Moon system to make sure everything is working well before we send the crew on their interplanetary missions, so far from help from Earth, or any possibility of aborting back to Earth. And many of the ideas the enthusiasts have developed for Mars will work as well or better on the Moon, as we'll see.
So, that maybe gives you an idea of where this is headed. Please be patient with me as I answer those points made by the Mars colonization enthusiasts one at a time. There is a lot to answer there.
IDEA THAT WE HAVE TO BECOME MULTI-PLANETARY TO SURVIVE
First, there's this whole narrative that we have to go to Mars because we need to become multi-planetary. Do we? Would it help at all to have a "backup" on Mars? Let's start with this one, as it is often given as the main reason we "have" to go to Mars. Elon Musk says this over and over. We have to become interplanetary and Mars is the only way to do it.
I can see value in a small colony on the Moon - a seed bank, more geologically stable than the one in Norway - passively cooled, immune to any effects of climate change. Also a knowledge bank too, an information repository which can be designed to last for millions of years. One that could be designed also so that it can be interrogated from Earth via radio waves.
That's a sensible "backup". Just an extra one. As a programmer I'm keen on multiple backups. Although it's not likely we ever need it, well, it is extra insurance to have a backup on the Moon. So why not? If we can afford it. Far far less expensive than an attempt at a Mars colony for sure.
And what do you use the backup for? Well, to restore Earth of course. There is nothing, nothing at all that could make Earth anything like as uninhabitable as Mars.
A nuclear war can't do it. You would have to cobalt bomb all of Earth, and nobody has been insane enough to develop cobalt bombs - nuclear weapons designed to make areas of Earth uninhabitable for decades. Carpet cobalt bomb all of Earth - and the result is still a safer place to live, as regards radioactivity - than Mars. You could clear an area of the soil of radioactivity and build a habitat over it, filter out radioactivity in the air, and the result is much more habitable than anywhere on Mars. There is no way to clear some of the surface of Mars of the incoming cosmic radiation. All you can do is to live underground or cover your habitats in meters of regolith.
We can breathe the air.
IDEA THAT MARS IS THE ONLY SENSIBLE PLACE FOR HUMANS TO COLONIZE
So, first, actually, the 24 hour day is about the only thing that's Earth-like about Mars. It's actually a disadvantage too, it means that you have to engineer for huge swings in temperature every day, between above 0 C to the coldest temperatures in Antarctica and below, and you have twelve hours a day without solar power.
We have a far more attractive place for humans right close at hand at the lunar poles. The lunar poles are almost exactly perpendicular to the ecliptic, which means they don't really have seasons. They have solar power 24/7 just about year round and steady temperatures and very easy heat rejection.
The Mars thin atmosphere
IDEA THAT WE CAN SOLVE ALL THE MARS ISSUES BY TERRAFORMING IT - AND THEN IT WILL BE PERFECT FOR HUMANS
PLANETARY CHAUVINISM
