Currently hurtling through space, rapidly approaching its destination, NASA’s Perseverance rover will make the most difficult landing ever attempted on Mars on Thursday, before it begins its hunt for ancient life.
When it arrives Thursday afternoon, Perseverance will enter Mars’ atmosphere at over 12,000 miles per hour, streaking across the Martian sky like a meteor for seven nail-biting minutes before finally touching down in the Jezero Crater, a site that the Curiosity rover was technologically incapable of reaching.
NASA scientists call it the “seven minutes of terror.”
The rover must survive both intense heat comparable to the sun’s surface and deceleration as it descends, while also trying to land in the correct place. A parachute 70 feet in diameter will help slow it down, as it attempts to find its way to the crater.
Then, a “skycrane,” which was also used by Curiosity, will allow Perseverance to lower itself onto the surface. When the rover finally lands, it will touch down on its wheels at a speed slower than humans walk.
“I don’t think I’m exaggerating when I say that entry, descent and landing (EDL) is the most critical and most dangerous part of the mission,” Allen Chen, the EDL lead, said this week during a news conference. “Success is never assured, and that’s especially true when we’re trying to land the biggest, heaviest and most complicated rover we’ve ever built to the most dangerous site we’ve ever attempted to land on.”
And Perseverance has to do this all on its own. It takes radio signals more than 11 minutes to get back to Earth, so the entirety of the EDL will be done without the help of mission control.
NASA chose the Jezero Crater as the landing site because scientists believe, based on orbital photographs of the region, that it was once filled with water, home to an ancient river delta. The water is long gone, but lakebed deposits make the crater an ideal place to investigate for signs of ancient life.
The crater is filled with steep cliffs, sand, boulders and impact craters, all of which make the landing more difficult. When Perseverance touches down, it must do so near the remnants of the delta, where traces of microbial organism could have settled.
“Jezero Crater is a great place, a magnificent place for science. But when I look at it from a landing perspective, I see danger,” Chen said. “It’s a formidable challenge.”
The Perseverance rover, which launched last July, is the biggest vehicle NASA has ever attempted to land on Mars, weighing over a metric ton and carrying 50% more science and technology than Curiosity, which landed in 2012. Two new technologies will help Perseverance land safely — a range trigger, which allows the rover to decide when to deploy the parachute, and terrain relative navigation, which essentially gives the rover eyes and a map, so it can check to make sure it lands in the right place.
“If it wasn’t for range trigger and terrain relative navigation, we just could not go to Jezero,” Chen said.