Over the next few days, three space probes launched by three different countries last July will reach Mars: an orbiter called Al Amal (Hope), launched by the UAE, two landing craft (“catcher”, one must say), one Chinese, intentionally Tianwen -1 (Questions to Heaven), the other American, the robot perseverance. This coincidence in the arrival of the three probes is not the result of coincidence: Every 26 months or so, Earth and Mars meet together as close as possible to each other, which opens an ideal launch window, from which space agencies benefit from reaching the Red Planet at a lower cost (with fuel) and after a while Less flying.
Mars exploration isn’t new: the first probe launched toward our Soviet neighbor Mars 1, It was November 1962. The first flight and the first images of the surface of Mars date back to 1965, with the American probe Mariner 4. Since then, dozens of orbital probes, surface probes and moving robots have been launched to Mars, with a marked increase in the number of missions over the past 20 years.
Why is this attention? First, because Mars is relatively close to Earth and thus easier to access compared to many other planets; On the other hand, the Red Planet is not much different from ours, with its hard surface, atmosphere, and relatively temperate climate (if you like polar cold, of course!).
More importantly, Mars was likely covered in water three to four billion years ago, which increases the interesting possibility that life appeared, even if only briefly, on the red planet. Scientists would like to discover the fossil traces of this primitive life. Many also wonder if it is possible for Mars life to live to this day in microscopic form, well protected in groundwater buried beneath the surface. So searching for traces of water and possibly past or present life on the Red Planet is the main driver of Mars exploration.
Prestige and dominance
But this is not the only engine; Space exploration also serves nations to increase their prestige and establish political and military dominance here on Earth. The race for the moon in the 1960s pitted the United States against the Soviet Union, as each nation attempted to demonstrate its political superiority through its technological prowess.
Sixty years later, some of the actors have changed (Russia’s exit, the entry of China and others of lesser importance, such as India), but the geopolitical goal remains the same. We are exploring an area of scientific knowledge, of course, but also to pump our muscles in front of the world. The rise of China, which recently launched probes to the Moon and now Mars, and which aims to create its own space station in Earth orbit, should not leave anyone indifferent …
There is also a mirage of human exploration of the red planet that partially stimulates space states. Let’s forget for a moment the expectations that place humans on Mars in the year 2030 or 2040, and instead ask ourselves why we risk throwing humans on such an adventure.
Space is a hostile place for the vulnerable creatures we are. Ionizing radiation causes the body to age prematurely, not to mention the cancer risks associated with overexposure. In weightlessness, the human body loses so much muscle mass and bone mass (a form of osteoporosis), so that astronauts cannot stand on their feet and take them back to Earth after long periods on board the International Space Station. Weeks, if not months, to regain their ability to move normally.
Make room for robots
So what will the astronauts land on Mars do after a months-long journey in space? Will they be able to stand despite the lowered gravity? In which country will we find them when we return from their mission? And what will happen in the event of an accident that we cannot help them?
In contrast, the robots we send to Mars are becoming more complex and more capable of carrying out complex exploration missions for scientists on Earth, without endangering anyone’s health or life. If a robot with its missile explodes on takeoff, gets lost in space or crashes while attempting to land, then we build another robot and start over, that’s it! Such a disconnect is difficult to show if humans are on board …
There is one final issue regarding Mars exploration that hasn’t been talked about much, but which poses a real threat to the red planet: the possibility that the Martian environment might one day be contaminated with terrestrial microorganisms. There is a strict protocol (the space treaty ratified by the United Nations in 1967) to which all exploration states that launch devices towards the moon or planets are subject to it. This protocol provides, among other things, a comprehensive sterilization of any material potentially in contact with extraterrestrial environments.
The risk is far from assumed: There are microorganisms on Earth that are able to withstand extreme temperatures, high-pressure environments or a vacuum of space, and even repair their DNA after excessive exposure to ionizing radiation. Some of these extreme microorganisms have shown their ability to survive for long periods of time in space, as long as they take a trip to Mars. It would be ironic that the exploration of Mars is the origin of biological pollution that will make us discover on Mars life forms … Good Earth!