After a journey of 292.5 million miles (470.8 million kilometers), NASA’s Perseverance rover has finally reached its destination – an ancient lakebed in Jezero Crater on Mars. The rover, the most complex machine ever sent to the Red Planet, successfully touched down today at 12:55 PM PST (3:55 PM EST). It has also already sent back the first couple images, and more, higher-resolution ones will be coming in the next hours and days.
“This landing is one of those pivotal moments for NASA, the United States, and space exploration globally – when we know we are on the cusp of discovery and sharpening our pencils, so to speak, to rewrite the textbooks,” said acting NASA Administrator Steve Jurczyk. “The Mars 2020 Perseverance mission embodies our nation’s spirit of persevering even in the most challenging of situations, inspiring, and advancing science and exploration. The mission itself personifies the human ideal of persevering toward the future and will help us prepare for human exploration of the Red Planet in the 2030s.”
Landing on Mars is not easy in its thin atmosphere, and the time it takes to descend through the atmosphere to the surface is referred to as the “7 minutes of terror” where any technical or hardware problems could cause a fiery crash instead of a smooth landing. This sequence, called Entry, Descent, and Landing, or “EDL,” begins when the spacecraft reaches the top of the Martian atmosphere, travelling nearly 12,500 mph (20,000 kph).
“Landing on Mars is always an incredibly difficult task and we are proud to continue building on our past success,” said JPL Director Michael Watkins. “But, while Perseverance advances that success, this rover is also blazing its own path and daring new challenges in the surface mission. We built the rover not just to land but to find and collect the best scientific samples for return to Earth, and its incredibly complex sampling system and autonomy not only enable that mission, they set the stage for future robotic and crewed missions.”
Perseverance used both a huge parachute and a descent stage with thrusters to land. In the last portion, the rover is gently lowered to the surface on cables attached to the sky crane.
“Perseverance is NASA’s most ambitious Mars rover mission yet, focused scientifically on finding out whether there was ever any life on Mars in the past,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “To answer this question, the landing team will have its hands full getting us to Jezero Crater – the most challenging Martian terrain ever targeted for a landing.”
“The Perseverance team is putting the final touches on the complex choreography required to land in Jezero Crater,” said Jennifer Trosper, deputy project manager for the mission at JPL. “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.”
Following is the sequence of events that occur during landing:
- 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 p.m. EST (12:38 p.m. PST).
- 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 p.m. EST (12:48 p.m. PST).
- Peak heating: Friction from the atmosphere will heat up the bottom of the spacecraft to temperatures as high as about 2,370 degrees Fahrenheit (about 1,300 degrees Celsius) at 3:49 p.m. EST (12:49 p.m. PST).
- Parachute deployment: The spacecraft will deploy its parachute at supersonic speed at around 3:52 p.m. EST (12:52 p.m. PST). 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 p.m. EST (12:54 p.m. PST). 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 p.m. EST (12:55 p.m. PST).
The primary mission of Perseverance is to search for evidence of ancient microbial life. Unlike Curiosity, still roving in Gale Crater, it will look for direct evidence of life itself rather than just previous habitability. It will be the first mission since the Viking 1 and 2 landers in the late 1970s/early 1980s to do so.
But the rover will have other tasks as well. The four main science objectives of the mission are:
- Looking for Habitability: Identify past environments capable of supporting microbial life.
- Seeking Biosignatures: Seek signs of possible past microbial life in those habitable environments, particularly in special rocks known to preserve signs of life over time.
- Caching Samples: Collect core rock and “soil” samples and store them on the Martian surface.
- Preparing for Humans: Test oxygen production from the Martian atmosphere.
Jezero Crater is an ideal location to seek ancient Martian life since it used to hold a lake a few billion years ago. Today, there are still sediments, carbonates and clays that Perseverance will study, that could hold possible biosignatures such as chemical traces or even fossils like microbial mats.
As well as look for life, Perseverance will also test technologies that could be used by astronauts in future crewed missions, including production of propellant and oxygen from the Martian atmosphere, using the Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE). The Raman & Luminescence for Organics & Chemicals (SHERLOC), as well as looking for organics, will also carry small pieces of spacesuit material for testing in the harsh conditions. The Mars Environmental Dynamics Analyzer (MEDA) will study Martian weather.
The rover isn’t alone, either. It also has a companion, a small drone-like helicopter called the Ingenuity or Mars Helicopter. Flight tests will be conducted over a 30-day period, first lifting just a few feet off the ground, followed later by longer and higher flights. If it works, it will be the first powered aircraft to fly in the Martian skies. It will fly ahead of the rover as a kind of scout, looking for features of interest to examine closer.
It weighs 4 pounds (1.8 kg), is about 19 inches (0.49 meters) in height and its rotors span about 4 feet (1.2 meters) across. It is equipped with computers, navigation sensors and two cameras (one color and one black-and-white). It will rely on solar power to charge its batteries and heaters.
Perseverance landed near the edge of an old delta, where a river once emptied into the lake. The sediments, carbonates and clays in this region are an excellent place to search for traces of fossilized microorganisms. We don’t know yet what the rover will discover in its journeys, but it will be exciting to find out.
The rover will also store some of the rock and soil samples it obtains for later return to Earth, sometime later this decade. If any tantalizing clues are found by the rover’s own onboard laboratory, then those samples can be studied in even greater detail in labs back on Earth. If it works, to will be the first-ever sample return from Mars.
“Because of today’s exciting events, the first pristine samples from carefully documented locations on another planet are another step closer to being returned to Earth,” said Thomas Zurbuchen, associate administrator for science at NASA. “Perseverance is the first step in bringing back rock and regolith from Mars. We don’t know what these pristine samples from Mars will tell us. But what they could tell us is monumental – including that life might have once existed beyond Earth.”
“Perseverance is the most sophisticated robotic geologist ever made, but verifying that microscopic life once existed carries an enormous burden of proof,” said Lori Glaze, director of NASA’s Planetary Science Division. “While we’ll learn a lot with the great instruments we have aboard the rover, it may very well require the far more capable laboratories and instruments back here on Earth to tell us whether our samples carry evidence that Mars once harbored life.”
Stay tuned for more images and updates as they become available!
Perseverance was launched on July 30, 2020 onboard an Atlas V 541 rocket, from Cape Canaveral Air Force Station in Florida.
More information about Perseverance is available on the mission website.