'7 Minutes of Terror': How NASA's Perseverance Rover Will Land on Mars Thursday
The rover finishes its long journey to the red planet on February 18.
NASA's Perseverance rover will reach Mars on Thursday, February 18. It's been a long, long trek since it launched back in July 2020, but all journeys come to an end. Few journeys, however, end this spectacularly.
If it lands safely, Perseverance will begin its science mission focusing on the habitability of Mars in the ancient past. Before it can start that mission, however, it has to survive the "seven minutes of terror" that takes it from the top of the Martian atmosphere to the ground. The rover's much-anticipated landing on the dusty Martian surface is really just the beginning.
Here's a look at how Perseverance will get to the ground and a preview of what it'll be up to once it arrives.
Where is Perseverance landing?
The car-sized rover will land in the Jezero crater. Scientists believe this was once an ancient lakebed. There are signs that the lake had a delta where a river deposited sediment long ago. "Scientists think the environment here was likely to have preserved signs of any life that gained a foothold billions of years ago," according to NASA. That makes it a promising place to set the rover for its mission of detecting signs of ancient life.
How will Perseverance land?
There's no guarantee that the landing will go as planned. It's challenging, to say the least, and made all the more difficult by the fact that the spacecraft will have to execute the landing on its own.
Perseverance will use the "sky crane" landing technique that was successfully used by Curiosity in 2012. Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters, called this "the most challenging Martian terrain ever targeted for a landing." There are steep cliffs, sand dunes, and boulder fields that will make the landing perilous. Though, Perseverance is better equipped than any previous rover to handle those perils. That includes Terrain-Relative Navigation that will help it "see" the ground and determine a safe place to land.
Despite the many challenges, the team at the Jet Propulsion Laboratory (JPL) has confidence in the rover's chances. "The Perseverance team is putting the final touches on the complex choreography required to land in Jezero Crater," Jennifer Trosper, deputy project manager for the mission, said in a statement. "No Mars landing is guaranteed, but we have been preparing a decade to put this rover’s wheels down on the surface of Mars and get to work."
These are the stages of the landing, as shared by the JPL.
- Cruise Stage Separation: The part of the spacecraft that has been flying Perseverance—with NASA’s Ingenuity Mars Helicopter attached to its belly—through space for the last six-and-a-half months will separate from the entry capsule at about 3:38 pm ET on February 18.
- Atmospheric Entry: The spacecraft is expected to hit the top of the Martian atmosphere traveling at about 12,100 mph (19,500 kph) at 3:48 pm ET.
- Peak Heating: Friction from the atmosphere will heat up the bottom of the spacecraft to temperatures as high as about 2,370 degrees Fahrenheit (1,300 degrees Celsius) at 3:49 pm ET.
- Parachute Deployment: The spacecraft will deploy its parachute—the largest one ever sent to another planet—at supersonic speed at around 3:52 pm ET. The exact deployment time is based on the new Range Trigger technology, which improves the precision of the spacecraft’s ability to hit a landing target.
- Heat Shield Separation: The protective bottom of the entry capsule will detach about 20 seconds after the parachute deployment. This allows the rover to use a radar to determine how far it is from the ground and employ its Terrain-Relative Navigation technology to find a safe landing site.
- Back Shell Separation: The back half of the entry capsule that is fastened to the parachute will separate from the rover and its “jetpack” (known as the descent stage) at 3:54 pm ET. The jetpack will use retrorockets to slow down and fly to the landing site.
- Touchdown: The spacecraft’s descent stage, using the sky crane maneuver, will lower the rover down to the surface on nylon tethers. The rover is expected to touch down on the surface of Mars at human walking speed (about 1.7 mph, or 2.7 kph) at around 3:55 pm. The descent stage will then fly off a safe distance from the rover.
The atmospheric entry begins what has been referred to as the "seven minutes of terror." The rover is really on its own for this part of its trip, and NASA won't immediately know if each stage was successful. "Mission controllers also may not be able to confirm these milestones at the times listed above because of the complexity of deep-space communications," the agency said.
When the rover is safely on the Martian surface, one of its first activities is to take pictures of the area and send them back home. The team will begin to check the health of the rover over the next few days and weeks. The Perseverance team will spend more than a month inspecting the rover and loading new software to help with its search for ancient microbial life, according to NASA. At the same time, the team behind the Ingenuity Mars Helicopter will begin to make sure it is ready for the first-ever attempt at controlled flight on another planet.
You can see a full animation of the landing below.
How many rovers does NASA have on Mars?
If it survives the challenging landing, Perseverance will be NASA's fifth rover on Martian soil. It joins Sojourner, Opportunity, Spirit, and Curiosity.
Soujourner arrived in 1997, Spirit and Opportunity arrived just weeks apart in 2004, and Curiosity touched down in 2012. The latter is the only one of the four that is still active on the Martian surface. InSight is also on the planet's surface, landing in 2018 to start is geological study of the planet. Though, it's not a rover.
Yes, it's carrying a small helicopter.
There are many incredible things to note about Perseverance, but one exciting test that will be conducted involves a separate craft that the rover is carrying. Ingenuity is a four-pound helicopter bolted to the underside of Perseverance. It will attempt the first-ever controlled flight in another planet's atmosphere.
The helicopter is not part of Perseverance's mission to search for signs of ancient life. It's making the trip to show and test its capabilities in hopes of laying the groundwork for a new era of planetary exploration. Rovers have done remarkable things on Mars, but there are a lot of places they can't go because of the rocky terrain. Ingenuity and future airborne crafts like it may have the ability to explore topography that other missions have not yet been able to reach.
It will be an exciting test when it happens. However, for now, the thrilling science will be coming from the work done by Perseverance and its team back here on Earth.