Perseverance rover lands on Mars


Nandkumar M Kamat

Percy has landed on Mars. Percy is a nickname for a car-sized remote-controlled robotic rover named Perseverance. I was witness on Thursday February 19 early morning (IST) to the historic and pinpoint accurate landing of the $2700 million Mars robotic rover – Perseverance. It carries a suite of very powerful analytical instruments – some of which we have never seen in any other laboratory on Earth. I was among the two million excited viewers watching the event telecast live by NASA. It was nice to watch an NRI engineer, mission head, NASA, Swati Mohan smartly handling the last-minute complex manoeuvres. There was global applause after she said: “Touchdown confirmed”. The seven minutes of “terror” had ended.

NASA used a 1000-kilogram skycrane to make the landing safe. The rover landed some two kilometres southeast of Jezero’s fossilised delta, locating a safe flat spot, tilting only 1.2 degrees, amid
a field of hazards.

“We did successfully find that parking lot, and have a safe rover on the ground,” said Allen Chen, the head of the rover’s landing team at JPL. Science reporter Paul Voosen wrote immediately for ‘Science’ on the exciting landing: “The rover’s descent was as dramatic as it was choreographed. Plunging through the Martian atmosphere while experiencing temperatures of up to 1300 degrees C, the rover deployed a parachute as big as a basketball court as it approached its seven-kilometre-wide landing zone, the most precisely targeted of any NASA Mars lander. After identifying a safe haven free of dunes and boulders, the rover and its sky crane—a sort of rocket-propelled hovercraft—detached from the parachute. The sky crane, falling at a walking pace, unspooled the rover to the surface with nylon cords. Finally, moments before touchdown, the rover deployed its six cleated aluminium wheels. The sky crane cut the cords and flew off to crash a safe distance away. The news, relayed by NASA’s Mars Reconnaissance Orbiter with an 11-minute delay, was greeted with cheers by those in JPL’s control room. The region is informally dubbed “Canyon de Chelly,” after a national monument in Navajo tribal lands.”

It is difficult to describe the importance of this mission in a single article but a lot was at stake before Perseverance safely landed close to the pre-planned spot in the Jezero crater on Mars. This crater was filled with water about 3800 million years ago and carries ancient sediment. NASA decided that it is the best place to explore for any sign of life. It was exhilarating to watch the first black and white image slowly filling up the giant screen at the control centre. That was the proof that Perseverance had landed safely.

The rover is accompanied by a novel helicopter drone named Ingenuity. The team which designed the wonderful Curiosity rover was involved in designing Perseverance. It has more durable aluminium wheels with titanium spokes. The rover needing 110 watts power has a 210 centimetres long five jointed robotic arm. The rover would be powered by a radioisotope powered thermoelectric generator using plutonium oxide as fuel. Besides there is a pack of two rechargeable lithium ion batteries. The rover carries 19 cameras and two microphones. The seven powerful instruments include- Planetary instrument for X-Ray lithochemistry (PIXL) which would examine the chemistry of surface materials near the landing site. Then there is a radar imager (RIMFAX) for subsurface experiments. It can detect any underground water or brine up to a depth of ten metres. This was designed by Norway.

Mars Environmental Dynamics Analyzer (MEDA) has a set of sensors measuring temperature, wind speed and direction, pressure, relative humidity, radiation and dust particles and their size. MOXIE or Mars Oxygen Experiment Instrument would try to generate oxygen from the traces of carbon dioxide in the atmosphere of Mars. Curiosity had carried a chemical analyser called ChemCam but Perseverance carried an advanced version called SuperCam which would perform chemical composition analysis and also identify any biosignatures from the molecules it would map. Mastcam-Z is a stereoscopic imaging system which can zoom on any object. An ultraviolet spectrometer called SHERLOC would fire a laser beam to determine fine scale minerology and detect the organic compounds in surface layers. It would take a few weeks before the rover is tested and its batteries get charged. Then it would have to establish its direct communication with the control centre on Earth using the tall antenna. The first detailed pictures and videos would be expected in March when I would be writing in detail about the importance of this Mars 2020 mission of NASA.

While watching the landing live on YouTube it was nice to hear the voice of Indian American Swati Mohan who like Kalpana Chawla and Sunita Williams could inspire young students in India. When she said: “Touchdown confirmed, Perseverance is safely on the surface of Mars, ready to begin seeking the signs of life”, it was also a great moment for Indians in India. Mohan was in charge of the crucial and critical control and landing system of the rover. She performed her task with meticulous precision and offered an objective lesson for all the students of aeronautics.

With Chinese and UAE spacecrafts already orbiting Mars and Mangalyaan still going strong, the coming days would be full of news about the red planet. For science students and teachers in India this is a great opportunity to learn.