Marking the third and final arrival to the red planet this month, NASA¡¯s Perseverance rover is set to enter Mars later this week. Plunging through the thin Martian atmosphere, the rover will experience a very troubling time until it reaches the surface.?
What¡¯s even more concerning for the NASA team behind the mission is the fact that the rover will have to make this descent on its own.
As per NASA, Perseverance is scheduled to touch down on Mars on Thursday, February 18 at approximately 2:35 a.m. IST. The rover will touch the Martian base at Jezero Crater, a large impact crater about 45 kilometers wide, just north of the Martian equator.?NASA?considers it ¡°the most ideal places to find evidence of ancient microbial life.¡±
The descent will see the rover plunging at a speed of around 20,000 kmph with only a parachute and powered descent to break its fall.
It is thus understandably a very challenging experience. NASA says that out of all the missions ever sent to Mars (by any space agency), only about 40 percent have been successful. Perseverance¡¯s landing will hence mark an important milestone in NASA¡¯s attempt to explore the red planet under its Mars Exploration Program for future habitation.
With $2.4 billion (~Rs 17,449 crore) on the line, the respite comes in the fact that the space agency has equipped the system enough to beat the odds. Here is how -?
The Mars 2020 spacecraft, containing the car-sized Perseverance rover and a mini helicopter called 'Ingenuity', will follow the same entry, descent, landing process as was used to land the Curiosity Mars rover. This one, however, is equipped with new breakthrough technologies.
A crucial one among these is the heat shield that will protect the spacecraft from the extreme heat faced on entering the Martian atmosphere. Ten minutes before entering the atmosphere, the cruise stage will eject from the spacecraft and eventually burn up.
The package, however, will have to face temperatures of up to 3,800 degrees Fahrenheit (2,100 degrees Celsius). The heat shield will maintain the temperature inside to about 50 degrees Fahrenheit (10 Celsius).
The same atmospheric friction that will cause the extreme heat will also slow down the package from 13,200 to 1,000 miles per hour (5.9 to 0.45 kilometers per second).
Once the package reaches an altitude of 7 miles (11 kilometers) from the ground, a specially designed parachute will pop up, slowing it down to 9% of its original speed. From a distance of 8 km, the heat shield will be dropped altogether.
When the package will be at a height of just over 3 km, a radar will begin to calculate speed and altitude. The goal is to accurately determine the time at which to start powered descent. An early start can eat up the fuel early while a late start will crash the rover to the ground.
Around 80 seconds after heat shield separation, the backshell and parachute will separate and the package will enter a brief free fall. This free fall will then be broken at a height of a kilometre from the ground, as eight retrorockets will fire to slow down the package¡¯s descent to less than 3 kmph.
The landing gear will kick into action at this point. Four of the eight retrorockets will shut off, following which, three nylon ropes and an "umbilical cord" will spool out to lower the Perseverance rover on the Martian surface.
Once lowered, the spools will be cut from the rover and the descent stage will fly at least 150 metres away from the rover.?
Once on Mars, the six-wheeled Perseverance robot will spend at least one Mars year, equating to about 687 Earth days, on the planet. The accompanying Ingenuity helicopter will help with flyby missions by flying autonomously to nearby areas, thus expanding the exploration reach.
The duo will try to ¡°gather knowledge and demonstrate technologies that address the challenges of future human expeditions to Mars,¡± NASA says. Perseverance will do so by collecting samples of Martian rocks and storing them in cigar-sized capsules. These capsules will be left scattered on the red planet, which can then be picked up by a future rover.
¡°The main question Perseverance is trying to answer is: Was there ever ancient life on Mars?¡± NASA says.
A future mission will then collect these capsuled samples and return them to Earth. Once back home, scientists will use a variety of sophisticated instruments which are too large to transport to Mars to help answer the ever persistent question.