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NASA is set to accomplish an unprecedented feat: the agency’s Perseverance Mars rover is set to film its own high-stakes landing.
The vehicle has almost reached its destination. On February 18, after nearly seven months and 300 million kilometers of space travel, the robot is expected to dive into the thin Martian atmosphere, deploy a parachute and jetpack, and then gently land in an ancient lake bed.
Once installed, it will search for mineral deposits of an ancient lake, which may contain signs of ancient microbial life. The rover is programmed to cache samples of Martian rocks and soil so that a future mission can bring them back to Earth for scientists to study.
But first, the rover must land successfully.
“I don’t think I am exaggerating when I say that entering, descending and landing is the most critical and dangerous part of a mission,” said Allen Chen, who leads this process for the perseverance at NASA’s Jet Propulsion Laboratory. a press briefing. “Success is never guaranteed and this is especially true when we try to land the biggest, heaviest and most complicated rover we’ve ever built on the most dangerous site we’ve ever attempted. to land.
A series of precise, automated maneuvers must take place to safely deliver Perseverance to its destination. There is no room for error.
This is why aerospace engineers have a special nickname for this phase of a mission to Mars: “seven minutes of terror”.
For Perseverance, this process will be all the more terrifying because of its landing site. The Mars Jezero Crater is a dry lake bed rich in exposed layers of ancient rocks, which may contain remains of past microbial life. Steep cliffs cut through the middle of the landing site, along with sand dunes and boulders.
“Jezero Crater is a great place, a great place for science,” Chen said. “But when I look at it from the landing point of view, I see the danger.”
If Perseverance arrives safely, however, it will rebroadcast the first video footage of a landing on another planet. The rover’s high-definition cameras and microphones are expected to record everything, and NASA has said it will make the footage available later.
“We are really looking forward to getting everyone to come for the race,” Chen said.
A parachute and a jetpack will slow down the fall of Perseverance
Animation from NASA shows what the Perseverance landing should look like if all goes well:
The illustration below describes each step of this process.
“We have literally seven minutes to get from the top of the atmosphere to the surface of Mars, going from 13,000 mph down to zero in perfect order, perfect choreography, perfect timing,” said Adam Steltzner, chief engineer of the Perseverance mission. in a 2012 NASA-JPL video on the Curiosity rover (which still performs well on Mars). “The computer has to do everything by itself without the help of the ground. If something doesn’t work properly, it’s over.”
The first step in Perseverance’s landing process is for the spacecraft that took it 300 million kilometers to drop its cargo: a top-shaped capsule with the rover inside. This entry capsule will succumb to the gravity of Mars and plunge towards the planet, protecting Perseverance with a heat shield.
The capsule will roam the Martian atmosphere at over 12,000 km / h, and its shield should deflect material that has been overheated by this extreme speed. The outside of the heat shield will get as hot as 2370 degrees Fahrenheit. This will cause it to cross the Martian sky like a bright meteor.
Mars’ atmosphere is about 1% thicker than ours on Earth, but it should still slow the capsule down.
The capsule must use its thrusters to move toward the landing target, as air pockets of varying density can tilt it out of its path.
Once it’s slowed down to twice the speed of sound, Perseverance will deploy a 70-foot-wide parachute. Next, the capsule will release its heat shield, clearing the way for the rover’s radar system to monitor the land below. An autopilot-type navigation system must trigger to reconfigure the vehicle’s path to the landing site.
This system, called “relative terrain navigation”, compares what the rover’s cameras see with an onboard map of the Martian surface, constructed from satellite images. He should recognize and avoid the cliffs, sand dunes, and rocky fields that litter Jezero Crater.
Perseverance’s supersonic parachute can only slow its descent to about 150 mph – as fast as a parachutist diving on Earth without a parachute. That’s why NASA engineers also outfitted the rover with a jetpack.
About a mile above the Martian surface, the jetpack will ignite its engines, with the rover strapped to its underside.
The jetpack will separate from the remaining parts of the entry capsule and fly Perseverance to a safe location identified by terrain navigation. By the time the rover reaches its landing spot, its speed should have slowed to around 1.5 mph.
Very slowly the jetpack will unroll 25 foot long nylon cords which will lower perseverance until its wheels hit the ground.
A few minutes later, mission controllers should receive the signal that the rover has landed.
After that, assuming everything has gone well, the rover will spend a few months checking and calibrating its science instruments. Then, it will release a helicopter from its belly and turn its cameras towards the drone as it takes off for the very first controlled flight to another planet.
Then, the rover will continue its main mission: to search for ancient rocks that could contain clues of microbial alien life.
Read the original article on Business Insider
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