Perseverance rover is coming in for a Mars landing today

Landing day is finally here.

The NASA Perseverance rover has been on a nearly 300 million-mile journey since it left Earth more than 6 months ago. If all goes well, it’s expected to land on Mars around 3:55 p.m. ET.

Humanity’s love affair with Mars is an enduring one, full of wonder about the possibility of life on this mysterious neighboring planet. This historic mission is one step closer to searching for evidence that could give us the answer.

It just has to land successfully to begin that quest.

Perseverance is full of firsts. The search for signs of ancient life on Mars. The first helicopter fly on another planet. The first recordings of sound on the red planet.

NASA’s most sophisticated rover to date has a packed agenda for the next few years.

The rover will explore Jezero Crater, the site of an ancient lake that existed 3.9 billion years ago, and search for microfossils in the rocks and soil there. Follow-up missions will return samples of this site collected by Perseverance to Earth by the 2030s.

Along for the ride with Perseverance is an experiment to fly a helicopter, called Ingenuity, on another planet for the first time.

While we can’t watch the landing “live,” NASA is inviting the world to tune in to its countdown and landing commentary, which will stream live beginning on Thursday at 2:15 p.m. ET. Tune in via NASA’s public TV channel, website, app, YouTube, Twitter, Facebook, LinkedIn, Twitch, Daily Motion or THETA.TV. In a first, the agency will also offer a Spanish language show for the landing.

During the landing coverage, NASA’s mission control team will be able to confirm if the rover safely landed on the surface of Mars

Once the rover has landed on Mars, you can follow its journey using an interactive map. Any raw images sent back by the rover this week and going forward will also be immediately available to the public on NASA’s site.

Landing on Mars: ‘7 minutes of terror’

If successful, Perseverance will be NASA’s ninth landing on Mars and the agency’s fifth rover. First, it has to go through the infamous “seven minutes of terror.”

The one-way time it takes for radio signals to travel from Earth to Mars is about 11 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.

The ground teams tell the spacecraft when to begin EDL (entry, descent and landing) and the spacecraft takes over from there — and mission control begins an agonizing wait.

This rover is the heaviest 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 1.7 miles per hour seven minutes later when the rover softly lands on the surface.

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 — that will happen 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 to 1.7 miles per hour — or the average walking speed of a human.

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.

Timing

During NASA’s coverage, listen for specific callouts that share what’s happening during the landing time line.

Cruise stage separation is expected about 3:38 p.m. ET. This is the component that has safely carried Perseverance and Ingenuity through space since launch.

Perseverance will enter the atmosphere about 3:48 p.m. ET.

Finally, Perseverance is expected to land at 3:55 p.m. ET.

All of these times are subject to change because there is a certain unpredictability to the Martian atmosphere and what happens when a spacecraft enters it.

Data from NASA’s Mars Reconnaissance Orbiter will relay data from the rover throughout landing.

The orbiters around Mars can also send back any images, either taken by the rover or the orbiters, to Earth.

The agency’s Odyssey orbiter will fly over the landing site and communicate with the rover to confirm its health about 7:27 p.m. ET, according to NASA. Then, the European Space Agency’s ExoMars Trace Gas Orbiter will also do a check-in with Perseverance and return any images and data to Earth at 9:36 p.m. ET.

The mission: What the rover will do

Once the rover has landed, Perseverance’s two-year mission will begin. First, it will go through a “checkout” period.

Perseverance will capture images of its surroundings and send them back, unfold its “head” and take more pictures while going through some health checkups with engineers.

Teams on Earth will go through a month of inspections, software downloads and preparations for roving.

The helicopter team will make sure Ingenuity is safe, healthy and ready to fly, “a true extraterrestrial Wright Brothers moment,” according to Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate.

Over a process that takes about 10 days, the rover will drop the helicopter on the surface of Mars and roll away from it. The little 4-pound helicopter will have to survive frigid nights on Mars, keep itself warm and charge itself using solar panels. Then, it will be ready for its first flight, which will last about 20 seconds.

“The Ingenuity team will be on the edge of our seats with the Perseverance team on landing day,” said MiMi Aung, the Ingenuity project manager. “We can’t wait until the rover and the helicopter are both safely on the surface of Mars and ready for action.”

Perseverance will search for evidence of ancient life and study Mars’ climate and geology and collect samples that will eventually be returned to Earth by the 2030s.

“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.

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. To accomplish its goals, Perseverance will drive a little less than 0.1 mile per hour, three times faster than previous rovers.

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 used during future human exploration of the red planet.