There’s a rocket-powered sky crane involved.
NASA’s Perseverance rover is only a few days away from its daring seven-minute landing on Mars, where it will touch down on the most challenging terrain ever targeted by a Red Planet mission.
On Feb. 18, the car-size Perseverance — the heart of NASA’s Mars 2020 mission — will attempt to land inside the 28-mile-wide (45 kilometers) Jezero Crater. The entry, descent and landing (EDL) phase of a Mars mission is often referred to as “seven minutes of terror,” because the sequence is so harrowing and happens faster than radio signals can reach Earth from Mars. That means the spacecraft is on its own once it enters the Martian atmosphere — and a gripping new video from NASA shows how the rover will pull off such an amazing feat.
“Space always has a way of throwing us curveballs and surprising us,” Swati Mohan, Mars 2020 guidance, navigation and control operations lead at NASA’s Jet Propulsion Laboratory (JPL) in Southern California, says in the video. “There are many things that have to go right to get Perseverance on to the ground safely.”
NASA’s Perseverance Mars rover landing: Everything you need to know
The EDL phase begins when the spacecraft reaches the top of the Martian atmosphere and ends with a rocket-powered sky crane lowering Perseverance safely to the surface of the Red Planet. The entire EDL sequence takes roughly seven minutes, during which many crucial steps must take place. The stakes are very high on Thursday for Mars 2020, which will hunt for signs of ancient life and collect samples for humanity’s first interplanetary sample-return campaign.
“There is a lot counting on this,” Al Chen of JPL, Mars 2020 entry, descent and landing lead, says in the video. “This is the first leg of our sample return relay race — there is a lot of work on the line.”
Shortly before reaching the Red Planet, Perseverance will shed its cruise stage, which helped fly the rover to Mars over the last 6.5 months. The next big milestone is atmospheric entry, when the rover will barrel into the Martian skies at about 12,100 mph (19,500 kph).
The vehicle is equipped with a heat shield that will protect the rover from the intense heat generated during its initial descent and also help slow the spacecraft down. At about 7 miles (11 kilometers) above the surface, the spacecraft will deploy its 70.5-foot-wide (21.5 meters) supersonic parachute — the largest ever sent to another planet, according to the video.
Soon after, the heat shield will separate and drop away from the spacecraft, exposing Perseverance to the Martian atmosphere for the first time and jumpstarting the vehicle’s Terrain-Relative Navigation system, which is a new autopilot technology that will help guide the rover to a safe landing on Mars.
“Perseverance will be the first mission to use Terrain-Relative Navigation,” Mohan says in the video. “While it’s descending on the parachute, it will actually be taking images of the surface of Mars and determining where to go based on what it sees. This is finally like landing with your eyes open — having this new technology really allows Perseverance to land in much more challenging terrain than Curiosity, or any previous Mars mission, could.”
Perseverance’s EDL sequence is very similar to that of NASA’s Curiosity rover, which landed in 2012. However, Perseverance is slightly bigger and equipped with more advanced scientific instruments, including new technology that will help guide the spacecraft through its difficult landing.
Scientists believe an 820-foot-deep (250 m) lake filled Jezero Crater about 3.9 billion to 3.5 billion years ago. The area also has a prominent river delta, where water once flowed through and deposited lots of sediment. While this landing site offers geologically rich terrain, the rocks, craters and cliffs make it a very challenging place for Perseverance to land.
“The science team identified Jezero Crater as basically an ancient lake bed and one of the most promising places to look for evidence of ancient microbial life, and to collect samples for future return to Earth,” JPL’s Matt Smith, flight director for Mars 2020 cruise operations, says in the video. “The problem is, it is a much more hazardous place to land.”
During the final minute before Perseverance lands on the Red Planet, the mission’s sky-crane descent stage will fire up eight retrorockets, or Mars landing engines. Then, the sky crane will lower the rover safely to the ground on three nylon cables. Once the rover has made landfall, it will cut the cables connecting it to the descent stage, which will then fly off and crash-land safely away from Perseverance.
“Surviving that seven minutes is really just the beginning for Perseverance,” Chen says in the video. “Its job — being the first leg of sample-return; to go look for those signs of past life on Mars — all that can’t start until we get Perseverance safely to the ground, and then that’s when the real mission begins.”