The rover, which is the largest and most advanced rover NASA has ever built, will act as a robotic geologist, collecting samples of dirt and rocks that will eventually be returned to Earth by the 2030s.
For that reason, Perseverance is also the cleanest machine ever sent to Mars, designed so it doesn’t contaminate the Martian samples with any microbes from Earth, providing a false reading.
The mission teams have made many modifications due to the pandemic, but they have adapted to work safely and effectively. The team that will be at JPL during the landing conducted an adapted simulation of the landing that transpired last week over three days.
“Don’t let anybody tell you different — landing on Mars is hard to do,” said John McNamee, project manager for the Mars 2020 Perseverance rover mission at JPL, in a statement. “But the women and men on this team are the best in the world at what they do. When our spacecraft hits the top of the Mars atmosphere at about three-and-a-half miles per second, we’ll be ready.”
Perseverance is the latest step in NASA’s long history of exploring the red planet. It builds on lessons learned from previous missions with new goals that will shed more light on the history of Mars.
“NASA has been exploring Mars since Mariner 4 performed a flyby in July of 1965, with two more flybys, seven successful orbiters, and eight landers since then,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, in a statement.
“Perseverance, which was built from the collective knowledge gleaned from such trailblazers, has the opportunity to not only expand our knowledge of the Red Planet, but to investigate one of the most important and exciting questions of humanity about the origin of life both on Earth and also on other planets.”
The teams at NASA call it the “seven minutes of terror.”
And just weeks after the landing, video cameras and microphones on the spacecraft will show the rover’s perspective of this harrowing experience.
‘Seven minutes of terror’
The one-way light time it takes for radio signals to travel from Earth to Mars is about 10.5 minutes, which means the seven minutes it takes for the spacecraft to land on Mars will occur without any help or intervention from NASA teams on Earth.
This is the “seven minutes of terror.” The ground teams tell the spacecraft when to begin EDL (entry, descent and landing) and the spacecraft takes over from there.
It is no exaggeration to say that this is the most critical and dangerous part of the mission, according to Allen Chen, Mars 2020 entry, descent, and landing lead at JPL.
“It is not guaranteed that we will be successful,” Zurbuchen acknowledged. The mission teams, however, have done everything they can to prepare for a successful landing.
This rover is the heaviest that NASA has ever attempted to land, weighing in at over a metric ton.
The spacecraft hits the top of the Martian atmosphere moving at 12,000 miles per hour and has to slow down to zero miles per hour seven minutes later when the rover softly lands on the surface.
It will streak across the Martian sky like a meteor, Chen said.
About 10 minutes before entering the thin Martian atmosphere, the cruise stage that has carried the spacecraft on its journey through space is shed and the rover prepares for a guided entry, where small thrusters on the aeroshell help adjust its angle.
The spacecraft’s heat shield will endure peak heating of 2,370 degrees Fahrenheit, 75 seconds after entering the atmosphere.
Perseverance is targeting a 28-mile-wide ancient lake bed and river delta, the most challenging site yet for a NASA spacecraft landing on Mars. Rather than being flat and smooth, the small landing site is littered with sand dunes, steep cliffs, boulders and small craters.
The spacecraft has two upgrades — called Range Trigger and Terrain-Relative Navigation — to navigate this difficult and hazardous site.
Range Trigger will tell the 70.5-foot-wide parachute when to deploy based on the spacecraft’s position 240 seconds after entering the atmosphere. After the parachute deploys, the heat shield will detach.
The rover’s Terrain-Relative Navigation acts like a second brain, using cameras to take pictures of the ground as it rapidly approaches and determines the safest spot to land. It can shift the landing spot by up to 2,000 feet, according to NASA.
The back shell and parachute separate after the heat shield is discarded when the spacecraft is 1.3 miles above the Martian surface. The Mars landing engines, which include eight retrorockets, will fire to slow the descent from 190 miles per hour to about 1.7 miles per hour.
Then, the famed sky crane maneuver that landed the Curiosity rover will occur. Nylon cords will lower the rover 25 feet below the descent stage. After the rover touches down on the Martian surface, the cords will detach and the descent stage will fly away and land at a safe distance.
On the surface of Mars
Once the rover has landed, Perseverance’s two-year mission will begin, and it will go through a “checkout” period to make sure it’s ready.
The rover will also find a nice, flat surface to drop the Ingenuity helicopter so it has a place to use as a helipad for its potential five test flights during a 30-day period. This will occur within the first 50 to 90 sols, or Martian days, of the mission.
Once Ingenuity is settled on the surface, Perseverance will drive to a safe spot at a distance and use its cameras to watch Ingenuity’s flight.
This will be the first flight of a helicopter on another planet.
After those flights, Perseverance will begin searching for evidence of ancient life, study Mars’ climate and geology and collect samples that will eventually be returned to Earth via planned future missions. It will drive three times faster than previous rovers.
Jezero Crater was chosen as Perseverance’s home because billions of years ago, the basin was the site of a lake and river delta. Rocks and dirt from this basin could provide fossilized evidence of past microbial life, as well as more information about what ancient Mars was like.
“Perseverance’s sophisticated science instruments will not only help in the hunt for fossilized microbial life, but also expand our knowledge of Martian geology and its past, present, and future,” said Ken Farley, project scientist for Mars 2020, in a statement.
“Our science team has been busy planning how best to work with what we anticipate will be a firehose of cutting-edge data. That’s the kind of ‘problem’ we are looking forward to.”
The path Perseverance will traverse is about 15 miles long, an “epic journey” that will take years, Farley said. What scientists could discover about Mars, though, is worth the journey.
Perseverance also carries instruments that could help further exploration on Mars in the future, like MOXIE, the Mars Oxygen In-Situ Resource Utilization Experiment. This experiment, about the size of a car battery, will attempt to convert Martian carbon dioxide into oxygen.
Not only could this help NASA scientists learn how to produce rocket fuel on Mars, but also oxygen that could be use during future human exploration of the red planet.
“The mission provides hope and unity,” Zurbuchen said. “As our cosmic neighbor, Mars continues to captivate our imagination.”