More than half a century after Neil Armstrong fulfilled humanity's dream of landing on the moon, another space race is heating up – the landing on Mars. A string of missions to the Red Planet, along with NASA's Perseverance and China's ZhuRong, raises an inevitable question: When will humanity keep up? Mars rovers over the decades have delivered a lot of information, including the presence of water ice on Mars, which has sparked expectations that humans could land. But how long? And are we ready?
Toward the end of 2021, SpaceX CEO Elon Musk updated the timeline for humans to land on Mars. He said ambitiously: "The best case scenario is about 5 years, the worst case scenario is 10 years. He believes the biggest obstacle SpaceX wants to clear is to design a rocket that can optimize tonnage into orbit and then into Mars. As the most complex and advanced rocket ever built, the Starship, its engineering design is one of the determinants of the time scale.
So how realistic is this prediction?
Again, is it an exaggeration, or can SpaceX do it?
Musk is notorious for overproduction and under-delivery, the most obvious example being his claim that his Tesla electric car uses fully autonomous driving technology, and even Tesla admits that this is an exaggeration.
While SpaceX has indeed achieved incredible engineering feats, these are mostly innovations that involve the work we've been able to do, which is to put satellites into orbit and dock with the International Space Station. For now, the starship that Musk relies heavily on is an unproven technology in terms of space launches, and while there are good reasons to think it will eventually succeed, there are still many milestones to be met before seriously considering a Mars mission.
One of the biggest milestones is the Artemis moon landing, scheduled for sometime in 2025. That would give Musk's SpaceX five years from the time it landed on the moon to mars. Not impossible, but the likelihood of "punching the face again" is extremely high.
Still, we also need to remember that no one thought it was possible to reuse the rocket until SpaceX not only showed how it did it, but made it so routine that it became a key pillar of its very successful business plan. SpaceX may not have put Starship in orbit yet, but it has proven time and time again that skeptics are wrong, so even its boldest predictions can't be easily dismissed.
Moreover, we should definitely not confuse the human landing on Mars with the human colonization of Mars. If SpaceX manages to send a manned lander to Mars in December 2031, humans step on the surface of Mars for a few seconds, then immediately return to the lander, and then fly back to Earth, which is not as unlikely as it seems.
First, the trip to Mars on starship takes about 8 months, and the round trip takes about a year and a half. By 2031, NASA wants to build a permanent base on the moon that will have to be somewhat self-sufficient, and the technology will make long-distance trips to Mars more feasible.
Second, lifting off from the surface of Mars won't be much more difficult than lifting off from the moon.
The Moon's gravitational pull is about 16.67% of Earth's gravity, while Mars' gravitational pull is about 38% of Earth's gravity, so the speed required to lift off from the surface of Mars is twice the speed required on the Moon. From 1969 to 1972, the Apollo lander successfully left the moon, far below the resources SpaceX provided for Mars landing and liftoff.
SpaceX has proven that it can descend safely from a high altitude to land starship, so assuming it can do so after orbiting next year, all components should start preparing for a human landing on Mars in 2031. If all the R&D testing programs are successful over the next decade, Musk's predictions may be realized.
Can humans complete their journey to Mars?
When it comes to Mars colonization, most people are optimistic, but a considerable number of scientists are worried about whether humans can successfully reach Mars.
It is an undeniable fact that the human body was formed by millions of years of evolution on Earth. As a result, it is perfectly adapted to environments affected by certain gravitational and pressure values, and is protected from solar and cosmic radiation through the dual protection of the Earth's atmosphere and magnetosphere. If it leaves the environment, it will be subjected to a lot of physiological stress.
The first problem is microgravity, which has many consequences:
Bone decalcification: astronauts lose 12 times more bone than postmenopausal women;
Muscle mass loss: Life is too easy for zero gravity muscles and they disappear;
The heart becomes weaker: the less you do, the weaker and rounder the heart;
Body fluids (blood, lymphatic system) flow upwards to the upper part of the body. Our entire vascular system is designed to fight and pump upwards, and even if gravity disappears, it will continue to do so, creating problems such as the risk of thrombosis.
The loss of muscle mass and the weakness of the heart can be partially counteracted by a rigorous daily workout. Aboard the International Space Station, astronauts do two hours of high-intensity fitness (aerobics and weight training) a day, but return to Earth very weak. Weight training also slows bone decalcification, but remains one of the most worrying concerns about the health of potential Martian astronauts, as fractures can be fatal on Mars.
The second major problem is radiation in space – solar flares!
The Earth's dual protection (atmosphere and magnetosphere) partially blocks or deflects ultraviolet rays, completely blocks X-rays and gamma rays as well as solar wind particles and cosmic rays. This protection is equivalent to a concrete wall 30 meters thick, or a wall made of 80 cm of lead. Once they leave this natural barrier, the astronauts must be protected in other ways, through the spacecraft's insulating facilities and personal spacesuits, and so on.
Long flights will expose humans to one of the greatest horrors of space travel: solar flares. In fact, the Apollo lunar landing program did not solve this problem, but chose to take risks, because the days of the lunar mission will not coincide with solar events, but a months-long trip to Mars will be another matter.
And landing on Mars will face many difficulties...
epilogue:
While the risks of traveling to Mars are incredible, that's no reason for humans to shy away. Early Mars expeditions could have been as dangerous as any other in human history. Every astronaut knows they venture to another planet and may never get there, or may never come back, but they have no choice.
We may not see Mars colonization in our lifetime, but we feel the anticipation of every rocket that flies into the sky!
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