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Choose your sideThe idea behind the Rift is simple: for each topic of debate, we provide you with an expertise based on a pro-con approach, written by competent and legitimate experts. We want to help you make your own opinion, and guide you on first steps to civic engagement.
Mars: a new step for mankind?
Researcher at the laboratory “Atmospheres, environments, space observations” of the University of Versailles and CNRS (LATMOS)
“Because it’s there.” It was with these words that the English mountaineer George Mallory answered the New York Times in March 1923 when he was asked why he wanted to climb Mount Everest, something he never managed to achieve and which precipitated his downfall on his third attempt. It was with these same words that President Kennedy, echoing the same Mallory, justified in a memorable speech delivered in Houston in September 1962 the ambition to send a man to the Moon before the end of the decade.
Why, since the dawn of time, has mankind strived to cross the limits that nature and the universe seemed to impose on him? Is it not because this ancestral, imperious need to explore, to go further than the horizon has always been perceived as a challenge to mankind? A challenge to its curiosity, to its intelligence, to its imagination, to its will and to its ability to realize his dreams? What more memorable moment than that of Neil Armstrong marking the powdery soil of the Moon with his footprint? What moment is more inspiring for entire generations and has made NASA the most admired organization in the world?
But while this conquest of the Moon did not survive a certain media fatigue, the exceptional only happening once, mankind has tempered, in the following decades, its desire to leave its own footprint in new worlds. However, there is hardly a planet that has not been visited since by probes created by Man and never had mankind counted so many machines that went to visit the confines of the Solar System.
Mars seems to make us the promise of having been a world perhaps inhabited and therefore inviting to receive the visit of the living, even if this living would come from another world.
But a new challenge, even greater than that of the Moon, greater than all the quests ever accomplished, is still facing us. And this challenge is called Mars. But why a human on Mars? Because Mars is, of all the planetary bodies that can be visited by mankind, the one that offers itself most easily to us. Because Mars seems to make us the promise of having been a world perhaps inhabited and therefore inviting to receive the visit of the living, even if this living would come from another world.
Because the challenge that Mars will pose will not only be a challenge to intelligence but a challenge “to intelligences“, as it seems obvious that such an adventure, like the international space station, will only be possible thanks to the participation of numerous space powers carried by a common impulse and ambition, that of taking humanity further than it has ever been, that of breaking down a new frontier.
Is it possible to imagine a nobler, more peaceful enterprise than that of uniting these wills and these capacities to achieve such an end? Yes, and this enterprise is to keep the Earth the most habitable place for mankind. But this consideration should not prevent mankind from dreaming, nor from traveling and visiting other worlds and bringing back from its travels the conviction that the Earth is its most precious possession.
No, we should not send Man to Mars
Astrophysicist at the Department of Astronomy of the University of Geneva, member of Astronomers for Planet Earth, co-author of the book “Nous ne vivrons pas sur Mars ni ailleurs” (Editions Favre)
Spirit, Opportunity, Phoenix, Curiosity, InSight, Perseverance, and soon Tianwen, exoMars, and many more to come… Each new robotic probe increases our knowledge about the Red Planet. Each new probe is more efficient than the previous ones, building on our experience on Martian soil and on the quick progress of technology.
But they all share a common property: they don’t need to breathe, drink, eat, wash, pee… Mars is not a habitable planet. Sending humans there imposes to build a bubble of habitability for them. Compared to the complexity of a manned mission, robotic probes are cheap and easy, and their gain/cost balance is extremely positive.
The cost of sending a manned mission is equivalent to about 40 Perseverance-like missions, so more or less equivalent to all the missions (orbiters or landers) sent to Mars since the first successful orbiter in 1971. Despite humans being supposedly more efficient on the field than robots (yet), it is clear that the knowledge gathered by 40 robotic missions surpasses by far the outcome of one manned mission.
Despite humans being supposedly more efficient on the field than robots (yet), it is clear that the knowledge gathered by 40 robotic missions surpasses by far the outcome of one manned mission.
The risks of a mission to Mars are tremendous. Our bodies have evolved with Earth gravity and pressure for millions of years. Taken out to space or to another planet, they are weak and fragile. Microgravity during the journey takes its toll on bones (decalcification), muscles (loss of muscular mass), vascular system (weakening of the heart, excess of fluids in the upper body, high risks of thrombosis), and it is not yet clear whether the low gravity of Mars is enough to improve the situation or not.
Also, Earth offers a double protection against space radiation: the atmosphere acts as a concrete wall of 30 m, shielding us from the Sun’s UV, X, and gamma radiation; the magnetosphere traps and deviates solar wind’s particles and galactic cosmic rays. In one 2.5 years mission, the martionauts would get the maximal radiation dose tolerated along a full astronaut career. Many technical challenges are not yet met, as the most basic ones like how to land a heavy rocket and how to launch it again to bring them back.
Last but not least, for each human sent there, we will send billions of bacteria. Robotic probes are highly sterilised before launch, but humans won’t be, and setting foot on Mars means contaminating it, with the risk of erasing the answers to the one question that really matters: did life emerged once on Mars?