Will Perseverance Persevere Through the Seven Minutes of Terror?

Tomorrow, on February 18, 2021, Perseverance is expected to make its landing in Jezero Crater on the martian surface. The landing will mark a new era of the way we explore Mars and lets us be one step closer to finding life, and eventually colonizing Mars. However, the hardest part and most gut-wrenching part is yet to come, the 7 minutes of terror. 

Artists Rendering of Perseverance
and Ingenuity on Mars

On July 30th, Perseverance started its seven-month journey to Jezero crater, Mars, touching on Mars on February 21st, 2021. The Mars 2020 Rover Mission was started eight years ago, with Curiosity's landing at Aeolis Palus on Mars on August 6th, 2012. There are many missions that Perseverance will carry out, and there will be multiple firsts along with the mission. There are also multiple robotic and autonomous assemblies onboard Perseverance to help it carry out its numerous missions. The rover was developed at the Jet Propulsion Laboratory(JPL) in Pasadena, California, and will launch from Cape Canaveral Air Force Station in Cape Canaveral, Florida. This will be the fifth rover launched by NASA.

Animation of Trajectory of 
Mars, Earth, and Perseverance

As mentioned before, there are multiple missions, and firsts, that Perseverance is hoping to pull off during its time on Mars. Perseverance is hoping to collect more detailed samples of Mars's surface and drilling down into Mars to collect samples. Perseverance can hold between 20 and 30 drilled samples. Perseverance will do a multitude of things with these samples. It will use onboard equipment to tell the composition of the martian soil and determine if there is any form of life in the ground. Perseverance will also cache the samples in safe tubes and deposit them for the later collection so that NASA can test the samples on Earth. 

Jezero Crater

Perseverance will be landing at Jezero crater. Jezero crater was chosen as the landing site because there is evidence that there was a lake in Jezero crater billions of years ago. This is evident by the delta-like sand patterns and the entrance and exit streams from the crater. Scientists are hoping that they will be able to find signs of microbial life at Jezero crater. Before Jezero crater, multiple sites were being looked into as landing sites. These include Columbia Hills in Gusev crater, Eberswalde crater, Holden crater, Mawrth Vallis, Northeastern Syrtis Major Planum, Nili Fossae, and Southwestern Melas Chasma. The landing range is also smaller compared to prior years, showing how accurate the team at NASA and JPL have gotten at landing rovers. The landing destination could save weeks, and even months the closer they are to an actual collection site.

Landing Site Sizes Over All NASA 
Rover Missions

The entry, descent, and landing (EDL) phase is also called the 7 minutes of terror. This is because the rover will autonomously land itself and if anything is off by one second, the whole mission can fail. There are many different things that are done to safely land the rover on Mars. The EDL phase is very important, starting with entry into the Martian orbit and ending with a powered descent. It is the same system that was used on the Curiosity rover 9 years earlier.

Landing Sequence for Perseverance

Ten minutes before entering the Martian atmosphere, Perseverance will separate from its cruise stage which helped it navigate its way to Mars. After this, Perseverance will make its atmospheric entry. When it enters the Martian atmosphere, Perseverance will travel at nearly 12,100 mph (19,500 kph).

Perseverance's Heat Shield

This leads to an immense amount of heat due to friction caused by air resistance. To counter this, Perseverance has a heat shield that will protect the rover. The air resistance will also help to slow down the rover. However, it still isn’t slow enough to land safely. That is why Perseverance will use a supersonic parachute to slow itself down greatly. The parachute, which is 70.5 feet (21.5 meters) wide, will deploy at 7 miles (11 km) above the Martian surface. This parachute is also the largest parachute ever sent to another planet.

Perseverance's Supersonic Parachute

After Perseverance has slowed down enough, it will drop its heat shield and start the vehicle’s Terrain-Relative Navigation system. This new system is an autopilot technology that will help guide the rover to a safe landing. As Perseverance is descending closer to the Martian surface, it will take and send pictures of the landing surface, giving people the perspective that they are landing on Mars. During the final minutes before landing, the sky-crane descent stage will fire eight retrorockets to safely lower the rover towards the Martian surface. The sky-crane holds the rover using three nylon cables and cuts them once the rover has safely landed. It will then jettison away and crash land on the Martian surface away from Perseverance.

Sky-Crane Descent Stage Carefully
Landing Perseverance on Mars

Tomorrow marks a new era of space exploration. But it all depends on if Perseverance can persevere through the seven minutes of terror and land safely. After we get the landing confirmation from JPL, we will get to see the first images from Perseverance, as well as his little buddy, Ingenuity takes flight, which will mark the first powered flight on Mars. If you want to see an animation of the landing, check out this video published by JPL. To get information on where and when the live streams of Perseverance land, here is a link to NASA’s official timetable for streaming the landing.

Sources:

Chris James ARC DECRA Fellow. “'7 Minutes of Terror': a Look at the Technology Perseverance Will Need to Survive Landing on Mars.” The Conversation, 16 Feb. 2021, theconversation.com/7-minutes-of-terror-a-look-at-the-technology-perseverance-will-need-to-survive-landing-on-mars-155046. 

“Jezero (Crater).” Wikipedia, Wikimedia Foundation, 23 Nov. 2020, en.wikipedia.org/wiki/Jezero_(crater). 

“Mars 2020.” Wikipedia, Wikimedia Foundation, 24 Nov. 2020, en.wikipedia.org/wiki/Mars_2020. 

“Mars Helicopter Ingenuity.” Wikipedia, Wikimedia Foundation, 22 Nov. 2020, en.wikipedia.org/wiki/Mars_Helicopter_Ingenuity. 

“NASA's Mars 2020 Perseverance Rover Landing Animations.” Youtube, JPL, 21 Dec. 2020, www.youtube.com/watch?v=rzmd7RouGrM. 

“Perseverance (Rover).” Wikipedia, Wikimedia Foundation, 20 Nov. 2020, en.wikipedia.org/wiki/Perseverance_(rover). 

Pradhan, Arnav. Perseverance: The Rover or The Trait?, Blogger, 21 Dec. 2020, www.arnavpradhan.com/2020/11/perseverance-rover-or-trait.html. 

Wall, Mike. “A New 7 Minutes of Terror: See the Nail-Biting Mars Landing of NASA's Perseverance Rover in This Video.” Space.com, Space, 16 Feb. 2021, www.space.com/perseverance-mars-2020-rover-landing-video.