The sky above Mars will witness some amazing aeronautical displays in the next few days, when three probes of rival space robots arrive on the red planet after traveling millions of kilometers through space.
The orbit of the Hope spacecraft in the United Arab Emirates will arrive first, on Tuesday, followed by the Chinese spacecraft Tianwen-1 the next day. Finally, the American rover Perseverance will land dramatically on the surface of Mars on February 18.
It is a remarkable army that reveals the growing desire of many nations to develop their own space technology and explore the solar system. How well they succeed when they reach their target this week and next remains to be seen, however. Mars is an unforgivable place to visit.
.
Of the dozens of missions to Mars since 1960, about half have crashed or completely missed the planet due to component failures, rocket engine crashes or software errors.
“It can be a heartbreaking business,” said British physicist Colin Wilson of Oxford University. “I had instruments in two previous missions to Mars – the British Beagle Lander and the Schiaparelli spacecraft in Europe – and every time I was in the control room, squeezing my seat, as they descended. And on both occasions the wells collapsed. “
Mars is a difficult destination for several reasons. First, it is millions of miles away, said astrobiologist Susanne Schwenzer of Open University. “It’s not like going to the moon, which is only a quarter of a million miles away. This is the equivalent of a putt in a game of golf. Instead, Mars is incredibly far away. In golf terms, it is the equivalent of a complete and much more complicated tee-shot. ”
In addition, Mars has an atmosphere, but not a thick one. “That means there is enough air to trigger dust storms and winds that blow and push the lander off course and into danger,” Wilson added. “On the other hand, it’s not thick enough to allow you to use parachutes for the entire descent of the probe.”
In the past, American space engineers relied on mounting airbags on their probes, allowing them to rest after being dropped from a parachute. However, NASA’s new generation of rovers is too complex and difficult for such maneuvers, and perseverance will be based on a rocket platform called the celestial crane to lower it to the Martian surface.
This technique was used once before, in 2012, to land the American rover Curiosity. Now Perseverance, a much heavier rover, will follow suit on a journey that has been called “seven minutes of terror” by NASA. This is the time it will take for the SUV-sized rover, which weighs more than a ton, to reach the surface of Mars after hitting the planet’s upper atmosphere at over 13,000 mph.
Atmospheric friction will produce the first speed reduction. Then a huge parachute will be released automatically and this will reduce the speed of the probe to a few hundred miles per hour. Then the rocket crane engines of the sky crane will start and the probe will slow down until it rises about 20 meters above the surface of the red planet.
The crane will lower the rover on the cables until it reaches the surface, the cables will be cut and the sky crane will fly to make its own uncontrolled landing at a safe distance from Perseverance. Only then will a message be sent to NASA engineers to inform them of the good news.
Instead, the UAE Hope spacecraft, the first interplanetary spacecraft in the Arab world, will have a relatively simple time this week. It is designed only to orbit Mars, which it will accomplish by burning its main engine for 30 minutes.
If the combustion is successful, it will slow down the spacecraft enough to be captured by Mars’ gravitational field and enter orbit around it. Hope will spend the next two years studying Mars to better understand how, over billions of years, it lost a thick atmosphere that was able to support water vapor on its surface, but which was slowly transformed into a cold and arid world.
The Chinese Tianwen-1 is also scheduled to enter Martian orbit this week. He will study the planet for several months before dropping a lander that will transport a 250 kg rover robot to the planet. If it works, China will become only the second nation in the world to successfully land a robotic vehicle in another world, after the United States.
“China has already landed the rover safely on the moon, but it will be a much bigger achievement and will really show what scientists can do in their space today,” Schwenzer said.
Crucially, the three probes are part of a spearhead of missions that in the coming years should transform our knowledge of the planet, by returning the samples of Martian stone and soil to Earth for study. This task will be initiated by Perseverance, which is programmed to identify promising geological sites, extract soil samples and leave their caches in the selected locations. Future missions, involving Europe and the United States, will then take these samples and bring them back to Earth.
“When we do this, we hope to get answers to the simple question: is there, or has there been, life on Mars,” Schwenzer added.
“It’s a crucial issue – if life evolved on Mars, independent of life on Earth, it means that life evolved twice, separately, in the same solar system and is likely to be common in the cosmos.”