“The Perseverance rover will hunt for signs of ancient life and cache samples for future return to Earth.
NASA’s Perseverance rover isn’t just exploring the Red Planet. The life-hunting robot will also help a little bit of Mars make it to Earth a decade or so from now, if all goes according to plan.
Perseverance, the centerpiece of NASA’s $2.7 billion Mars 2020 mission, touched down inside the Red Planet’s Jezero Crater on Feb. 18, 2021. Once it’s fully up and running, the car-sized robot will search for evidence of past microbial life and collect several dozen samples for future return to Earth, among other ambitious tasks.
“I don’t think we’ve had a mission that is going to contribute so much to both science and technology,” NASA Acting Administrator Steve Jurczyk told Space.com shortly before Perseverance touched down. “It’s going to be truly amazing.”
If Perseverance looks familiar, that’s because the robotic explorer is largely based off its predecessor, the Mars Science Laboratory (MSL) Curiosity rover, which landed in August 2012 and is still going strong today.
Like Curiosity, the Perseverance rover was built by engineers and scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California. Roughly 85% of Perseverance’s mass is based on Curiosity “heritage hardware,” saving NASA time and money and reducing risk considerably, agency officials have said.
Perseverance is about 10 feet long (not including its robotic arm), 9 feet wide, and 7 feet tall (about 3 meters long, 2.7 meters wide and 2.2 meters tall). At 2,260 lbs. (1,025 kilograms), Perseverance weighs less than a compact car.
Like Curiosity, Perseverance has a rectangular body, six wheels, a robotic arm, a drill for sampling rocks, cameras and scientific instruments. But those instruments are quite different than the gear aboard Curiosity, because the two rovers have divergent goals. Curiosity’s main task involves assessing the habitability of ancient Mars, whereas Perseverance will hunt for evidence of ancient Martians.
Perseverance’s seven instruments “build on the success of MSL, which was a proving ground for new technology,” said George Tahu, NASA’s Perseverance program executive. “These will gather science data in ways that weren’t possible before.”
Perseverance also used the same entry, descent and landing (EDL) strategy as Curiosity. Both rovers hit the Mars atmosphere at tremendous speeds, deployed a supersonic parachute after friction slowed them down enough, and were finally lowered gently to the red dirt on cables by a rocket-powered “sky crane.”
But Perseverance had some EDL upgrades that Curiosity did not enjoy. For example, NASA’s Jet Propulsion Laboratory in Southern California, which manages the Mars 2020 mission, developed new landing technology called terrain-relative navigation. As the rover descended through the Martian skies, it used a computer to compare the landscape with pre-loaded terrain maps, guiding itself to a safe landing site and making corrections on the way down.
Another new feature, known as range trigger, used location and velocity information to determine when to open the supersonic parachute, narrowing the landing ellipse by more than half.
“Terrain-relative navigation enables us to go to sites that were ruled too risky for Curiosity to explore,” said JPL’s Al Chen, Perseverance’s EDL lead. “The ranger trigger lets us land closer to areas of scientific interest, shaving miles — potentially as much as a year — off a rover’s journey.”
Perseverance boasts nearly five times more cameras than the first Mars rover. Sojourner, which landed in 1997, carried only five cameras, and the twin rovers Spirit and Opportunity, which hit the red dirt in 2004, had 10 cameras apiece. Curiosity has 17.
Perseverance has 23 cameras. Several of them filmed the rover’s Mars arrival, capturing its landing in historic and unprecedented detail. The epic EDL video shows Perseverance’s parachute snap open in the Martian sky, for example, and documents the moment the robot’s six wheels hit the red dirt.
“For those who wonder how you land on Mars, or why it is so difficult, or how cool it would be to do so — you need look no further,” Jurczyk said in a statement a few days after touchdown.
“Perseverance is just getting started and already has provided some of the most iconic visuals in space exploration history,” he added. “It reinforces the remarkable level of engineering and precision that is required to build and fly a vehicle to the Red Planet.”
Some of Perseverance’s cameras provide more color and 3D imaging than Curiosity can collect, according to Jim Bell of Arizona State University, the principal investigator for Perseverance’s Mastcam-Z camera system. “Z” stands for “zoom,” one of the improvements on Curiosity’s high-definition Mastcam.
Spirit, Opportunity and Curiosity have all captured 1-megapixel images in black and white with their engineering cameras, which assist in drive planning and hazard avoidance. But Perseverance’s engineering cameras acquire high-resolution, 20-megapixel color images. Their wider field of view means that, instead of spending time taking multiple images to be stitched together on the ground, the new cameras capture the same view in a single snapshot. The cameras also reduce motion blur, so they can take photos while the rover is traveling.
More detailed images mean more data to beam through space.
“The limiting factor in most imaging systems is the telecommunications link,” said Perseverance imaging scientist Justin Maki of JPL, the instrument operations team chief. “Cameras are capable of acquiring much more data than can be sent back to Earth.”
Smarter rover cameras are helping to reduce the load. On Spirit and Opportunity, photo compression was done using the onboard computer. On Perseverance, as on Curiosity, compression is performed by electronics built into the camera.
Perseverance’s data is beamed back to Earth via several spacecraft orbiting Mars: NASA’s Mars Odyssey, Mars Reconnaissance Orbiter (MRO) and MAVEN (Mars Atmosphere and Volatile Evolution), and the European Space Agency’s Trace Gas Orbiter.
Odyssey was the first orbiter to send rover data home from Spirit and Opportunity.
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“We were expecting to do that mission on just tens of megabits each Mars day, or sol,” Bell said, referring to Spirit and Opportunity’s work. “When we got that first Odyssey overflight, and we had about 100 megabits per sol, we realized it was a whole new ballgame.”
Mastcam-Z is one of Perseverance’s seven science instruments. Another, known as SHERLOC (“Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals”), will be the first instrument on Mars to use Ramen and fluorescence spectroscopies, techniques familiar to forensics experts.
When an ultraviolet light shines over certain carbon-based chemicals, they glow much like material beneath a black light. The glow can help scientists detect chemicals that form in the presence of life. SHERLOC will photograph the rocks it studies, then map the chemicals it detects across the images.
“This kind of science requires texture and organic chemicals — two things that our target meteorite will provide,” Rohit Bhartia of JPL, SHERLOC’s deputy principal investigator, said in a statement.
The space rock mentioned by Bhartia is the Martian meteorite Sayh al Uhaymir 008 (SaU008), which the team will use to help calibrate SHERLOC. Previous rovers have included calibration targets, but none of them have ever relied on Martian meteorites. (A meteorite has, however, ridden to Mars aboard the Mars Global Surveyor, which ceased operations in January 2007.)
Another Perseverance instrument, called PIXL (“Planetary Instrument for X-ray Lithochemistry”), will determine the composition of Martian materials at a very fine scale using a high-resolution camera and X-ray fluorescence spectrometer.
The rover’s SuperCam instrument, an evolution of Curiosity’s ChemCam, will zap target rocks with lasers and determine the chemical composition of the resulting vapor.
Perseverance also carries a ground-penetrating radar instrument called RIMFAX (“Radar Imager for Mars’ Subsurface Experiment”). RIMFAX will be the first rover instrument ever to look under the surface of Mars, mapping layers of rock, water and ice up to 33 feet (10 m) deep.
Also aboard the rover is a weather station known as MEDA (“Mars Environmental Data Analyzer”) and a technology demonstration called MOXIE (“Mars Oxygen In-Situ Resource Utilization Experiment”).
MOXIE is designed to generate oxygen from the Red Planet’s atmosphere, which is 95% carbon dioxide by volume. Such gear, if scaled up, could help humanity get a foothold on the Red Planet in the future, NASA officials have said. (The agency aims to put boots on Mars in the 2030s.)
SHERLOC, PIXL and Perseverance’s rock drill sit at the end of the rover’s 7-foot-long (2.1 m) robotic arm, which can move with five degrees of freedom. MEDA, MOXIE and RIMFAX are on Perseverance’s body, and Mastcam-Z and SuperCam are on the rover’s headlike mast.”