Exploration of astronomical objects like nearest moons and planets of our solar system has always been a subject of great interest not only to scientists and engineers but also to common people in order to quench the curiosity towards the possibility of life other than earth. National Aeronautics and Space Administration (NASA) an American independent space agency is always in the forefront in these activities and now many other countries are also expediting their efforts in this direction.  Moon has been explored to a great extent as not only rovers but even humans have landed successfully on the moon surface.  On Thursday, NASA could have made it possible to land its Perseverance (largest and most advanced) rover on Mars surface successfully. Rover touched down on the surface of Mars after surviving a blazing seven-minute plunge through the Martian atmosphere.

Rover and its journey

The rover is about the size of a car, the 2,263-pound (1,026-kilogram) robotic geologist and astrobiologist will undergo several weeks of testing before it begins its two-year science investigation of Mars' Jezero Crater. Packed with ground breaking technology, the Mars 2020 mission was launched July 30, 2020, from Cape Canaveral Space Force Station in Florida. The Perseverance rover reached Mars after covering a 203-day journey traversing 293 million miles (472 million kilometres). Perseverance is NASA's ninth landing on Mars and the agency's fifth rover. The one-way time it takes for radio signals to travel from Earth to Mars is about 11 minutes, which means the seven minutes it takes for the spacecraft to land on Mars occurs without any help or intervention from NASA teams on Earth. This rover is the heaviest NASA has ever attempted to land, weighing in at over a metric ton. The spacecraft hit the top of the Martian atmosphere moving at 12,000 miles per hour and had to slow down to 1.7 miles per hour seven minutes later when the rover softly landed on the surface. The spacecraft's heat shield endured peak heating of 2,370 degrees Fahrenheit.

Aim of mission

The aim of exploration is not only the search for life on Mars but it will open a new platform for various other scientific activities. The Perseverance rover mission marks an ambitious first step in the effort to collect Mars samples and return them to Earth. The mission itself personifies the human ideal of persevering toward the future and will help to prepare for human exploration of the Red Planet in the 2030s. While the rover will investigate the rock and sediment of Jezero's ancient lakebed and river delta to characterise the region's geology and past climate, a fundamental part of its mission is astrobiology, including the search for signs of ancient microbial life. To that end, the Mars Sample Return campaign, being planned by NASA and the European Space Agency, will allow scientists on Earth to study samples collected by Perseverance to search for definitive signs of past life using instruments too large and complex to send to the Red Planet. Further steps will be to land humans on the Mars surface and then to go for space tourism.

The landing marks the third visit to Mars in just over a week. Two spacecraft from the United Arab Emirates and China swung into orbit around Mars on successive days last week. All three missions lifted off in July to take advantage of the close alignment of Earth and Mars, traveling some 300 million miles in nearly seven months. Nasa scientists describe Perseverance as the most ambitious of nearly 20 US missions to Mars dating back to a 1965 Mariner fly-by. Perseverance will spend the coming years scouring for signs of ancient microbial life in a historic mission that will bring back samples from Mars to Earth and prepare the way for future human visitors. The rover is equipped with a record 25 cameras and two microphones, many of them turned on during descent. Over the next two years, rover will use its 7-foot (2-meter) arm to drill down and collect rock samples with possible signs of bygone microscopic life. Three to four dozen chalk-size samples will be sealed in tubes and set aside on Mars to be retrieved by a fetch rover and brought homeward by another rocket ship. The goal is to get them back to Earth as early as 2031. Perseverance will also conduct an experiment in which it will convert small amounts of carbon dioxide in the atmosphere into oxygen, a process that could be a boon to future astronauts by providing breathable air and an ingredient for rocket fuel.

Indian significance

The Indian-American leading NASA's Perseverance rover landing on Mars. Among the scientists who are part of this historic mission, Indian-American Dr Swati Mohan spearheaded the development of attitude control and the landing system for the rover.  Apart from being the lead systems engineer during the development process, she also looks after the team and schedules the mission control staffing for GN&C.

NASA scientist Dr Mohan emigrated from India to America when she was just a year old. She spent most of her childhood in the Northern Virginia-Washington, DC metro area. At the age of 9, after having watched 'Star Trek' for the first time, she was quite astounded by the beautiful depictions of the new regions of the universe that they were exploring. She had immediately realised that she wanted to do that and "find new and beautiful places in the universe." Dr Mohan holds a Bachelor of Science degree in Mechanical and Aerospace Engineering from Cornell University and completed her MS and PhD from MIT in Aeronautics/Astronautics.

Perseverance is bringing seven science instruments to Mars, including:

• Mastcam-Z: Color cameras capable of panoramic and stereoscopic imagery.
• SuperCam: A combination camera, rock-vaporizing laser, and spectrometer that can identify the composition of rocks and soils in areas that the rover’s arm can’t reach.
• SHERLOC: A close range microscopic camera and spectrometer that the rover can move within just a few centimeters of a rock for a detailed analysis, specifically designed to detect organic molecules as well as observing bits of spacesuit material to see how well they handle the Martian atmosphere over time.
• PIXL: Another microscopic analysis tool which includes an X-ray fluorescence spectrometer to detect very small scale (like, grain of salt scale) changes in the composition and texture of rocks.
• RIMFAX: Ground-penetrating radar that can detect water or ice 10 meters beneath the surface underneath the rover.
• MEDA: A suite of sensors that measure temperature, pressure, humidity, wind speed and direction, and atmospheric dust characteristics.
• MOXIE: Moxie will try to convert Martian atmosphere (96% CO2) into useful oxygen with carbon monoxide as a by-product via an electrolyser heated to 800 degrees C. 
• Sample Caching System: A huge chunk of rover is devoted to taking samples of the Martian surface, analysing them, and storing them. These samples will be sealed up and left on the surface, with the idea that in a decade or so, another robot will come along, scoop them up, put them into a rocket, and fire them back to Earth. 
• Helicopter: The last thing that rover is carrying with it to Mars is an honest-to-goodness helicopter.