NASA’s Perseverance rover, the flagship of the $2.7 billion Mars 2020 mission, represents a bold leap in planetary exploration. Designed to search for signs of ancient life, it will collect and cache samples for eventual return to Earth and test new technologies that could shape the future of interplanetary travel. But before any of these objectives can be pursued, the rover must survive a perilous descent into Jezero Crater—a challenge that has defeated many missions in the past.
Historically, only about 40% of Mars surface missions have landed successfully. While early decades of the Space Age were marked by frequent failures, NASA’s more recent track record has been strong. Perseverance will rely on the “sky crane” landing method, first proven by the Curiosity rover in 2012, to deliver the car-sized vehicle safely to the Martian surface.
Launched on July 30, 2020, Perseverance builds on Curiosity’s work studying Mars’ habitability and climate history. It is the first surface mission to actively hunt for evidence of ancient microbial life. The rover will store dozens of carefully selected samples, which a joint NASA–European Space Agency effort aims to return to Earth as early as 2031. Such material could be analyzed with instruments far more sophisticated than those a rover can carry, offering unprecedented scientific insight.
Mars 2020 also carries notable technology demonstrations. Ingenuity, a small helicopter mounted beneath Perseverance, will attempt the first powered flight on another planet. If successful, it could pave the way for aerial exploration of Mars. Another payload, MOXIE—the Mars Oxygen In-Situ Resource Utilization Experiment—will produce oxygen from the planet’s thin, carbon dioxide-rich atmosphere, a capability that could one day support human missions.
The landing site, Jezero Crater, is a 28-mile-wide depression located about 18 degrees north of the Martian equator. More than 3.5 billion years ago, Jezero contained a lake comparable in size to Lake Tahoe and an associated river delta. Observations from NASA’s Mars Reconnaissance Orbiter have revealed clay minerals on the crater floor, materials known on Earth to preserve signs of microbial life. “On Earth, scientists have found such clays in the Mississippi River delta, where microbial life has been found embedded in the rock itself,” NASA officials noted, underscoring Jezero’s potential as a repository of ancient biosignatures.
Perseverance’s entry, descent, and landing (EDL) sequence will unfold on February 18, 2021. Ten minutes before atmospheric entry, the spacecraft will discard its cruise stage, which provided power, fuel, and communications during the journey from Earth. It will then strike Mars’ atmosphere at nearly 12,500 mph (20,000 km/h). Atmospheric drag will slow the craft, but friction will heat the heat shield’s exterior to 2,370 degrees Fahrenheit (1,300 degrees Celsius). Inside the aeroshell, Perseverance will remain near room temperature.
About four minutes after entry, a 70.5-foot-wide supersonic parachute will deploy, slowing the descent to roughly 940 mph (1,512 km/h). This deployment will be guided by Range Trigger, a new system that optimizes parachute release timing. Twenty seconds later, the heat shield will drop away, exposing Perseverance to the Martian air and allowing its radar and cameras to begin mapping the terrain. Terrain-Relative Navigation will compare these images to preloaded maps, enabling the rover to steer toward the safest reachable landing spot.
The parachute will reduce speed to about 200 mph (320 km/h), still too fast for a safe touchdown. At 6,900 feet (2,100 m) altitude, the back shell and parachute will be released, and the sky crane’s eight thrusters will ignite, slowing the descent to 1.7 mph (2.7 km/h). At 65 feet (20 m) above the surface, the crane will lower Perseverance on cables. Once the rover’s wheels touch down, the cables will be cut, and the descent stage will fly off to crash at a safe distance.
Touchdown is targeted for 3:55 p.m. EST (2055 GMT). The entire EDL will be autonomous, as the 11-minute signal delay between Mars and Earth makes real-time control impossible. NASA will broadcast coverage starting at 2:15 p.m. EST, with the possibility of high-definition video and audio from the rover’s onboard cameras and microphone capturing the landing in unprecedented detail.