Perseverance rover hightails it to Martian delta

Hexbyte Glen Cove

NASA’s Perseverance Mars rover looks back at its wheel tracks on March 17, 2022, the 381th Martian day, or sol, of the mission. Credit: NASA/JPL-Caltech

NASA’s Perseverance Mars rover is trying to cover more distance in a single month than any rover before it—and it’s doing so using artificial intelligence. On the path ahead are sandpits, craters, and fields of sharp rocks that the rover will have to navigate around on its own. At the end of the 3-mile (5-kilometer) journey, which began March 14, 2022, Perseverance will reach an ancient river delta within Jezero Crater, where a lake existed billions of years ago.

This delta is one of the best locations on Mars for the rover to look for signs of past microscopic life. Using a drill on the end of its robotic arm and a complex sample collection system in its belly, Perseverance is collecting rock cores for return to Earth—the first part of the Mars Sample Return campaign.

“The delta is so important that we’ve actually decided to minimize science activities and focus on driving to get there more quickly,” said Ken Farley of Caltech, Perseverance’s project scientist. “We’ll be taking lots of images of the delta during that drive. The closer we get, the more impressive those images will be.”

The science team will be searching these images for the rocks they’ll eventually want to study in closer detail using the instruments on Perseverance’s arm. They’ll also hunt for the best routes the rover can take to ascend the 130-foot-high (40-meter-high) delta.

But first, Perseverance needs to get there. The rover will do this by relying on its self-driving AutoNav system, which has already set impressive distance records. While all of NASA’s Mars rovers have had self-driving abilities, Perseverance has the most advanced one yet.

“Self-driving processes that took minutes on a rover like Opportunity happen in less than a second on Perseverance,” said veteran rover planner and flight software developer Mark Maimone of NASA’s Jet Propulsion Laboratory in Southern California, which leads the mission. “Because autonomous driving is now faster, we can cover more ground than if humans programmed every drive.”






NASA’s Perseverance Mars rover will follow the proposed route to Jezero Crater’s delta shown in this animation. The delta is one the most important locations the rover will visit as it seeks signs of ancient life on Mars. Credit: NASA/JPL-Caltech/ASU/MSSS/University of Arizona

How rover planning works

Before the rover rolls, a team of mobility planning experts (Perseverance has 14 who trade off shifts) writes the driving commands the robotic explorer will carry out. The commands reach Mars via NASA’s Deep Space Network, and Perseverance sends back data so the planners can confirm the rover’s progress. Multiple days are required to complete some plans, as with a recent drive that spanned about 1,673 feet (510 meters) and included thousands of individual rover commands.

Some drives require more human input than others. AutoNav is useful for drives over flat terrain with simple potential hazards—for instance, large rocks and slopes—that are easy for the rover to detect and work around.

Thinking while driving

AutoNav reflects an evolution of self-driving tools previously developed for NASA’s Spirit, Opportunity, and Curiosity rovers. What’s different for AutoNav is “thinking while driving”—allowing Perseverance to take and process images while on the move. The rover then navigates based on those images. Is that boulder too close? Will its belly be able to clear that rock? What if the rover wheels were to slip?

Upgraded hardware allows “thinking while driving” to happen. Faster cameras mean Perseverance can take images quickly enough to process its route in real-time. And unlike its predecessors, Perseverance has an additional computer dedicated entirely to image processing. The computer relies on a single-purpose, super-efficient microchip called a field-programmable gate array that is great for computer vision processing.

“On past rovers, autonomy meant slowing down because data had to be processed on a single computer,” Maimone said. “This extra computer is insanely fast compared to what we had in the past, and having it dedicated for driving means you don’t have to share computing resources with over 100 other tasks.”

Of course, humans aren’t completely out of the picture during AutoNav drives. They still plan the basic route using images taken from space by missions like NASA’s Mars Reconnaissance Orbiter. Then, they mark obstacles such as potential sand traps for Perseverance to avoid, drawing “keep out” and “keep in” zones that help it navigate.

Another big difference is Perseverance’s sense of space.

Curiosity’s autonomous navigation program keeps the rover in a safety bubble that is 16 feet (5 meters) wide. If Curiosity spots two rocks that are, say, 15 feet (4.5 meters) apart—a gap it could easily navigate—it will still stop or travel around them rather than risk passing through.

But Perseverance’s bubble is much smaller: A virtual box is centered on each of the rover’s six wheels. Mars’ newest rover has a more sensitive understanding of the terrain and can get around boulders on its own.

“When we first looked at Jezero Crater as a landing site, we were concerned about the dense fields of rocks we saw scattered across the crater floor,” Maimone said. “Now we’re able to skirt or even straddle rocks that we couldn’t have approached before.”

While previous missions took a slower pace exploring along their path, AutoNav provides the science team with the ability to zip to the locations they prioritize the most. That means the mission is more focused on its primary objective: finding the samples that scientists will eventually want to return to Earth.



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Perseverance rover hightails it to Martian delta (2022, March 18)
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Hexbyte Glen Cove Perseverance dumps contents of Sample Tube 261 in first step to clear rocky anomaly

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NASA’s Mars Perseverance rover acquired this image using its onboard SHERLOC WATSON imager. The camera is located on the turret at the end of the rover’s robotic arm. The image was acquired on Jan. 13, 2022 (Sol 320). Credit: NASA/JPL-Caltech

NASA’s Mars 2020 mission team has been working methodically and thoroughly, making good progress on understanding the best path forward to remove the uninvited pebbles from Perseverance’s bit carousel. Over the previous weekend, and earlier this week, operational sequences were developed and tested to remove these rocky interlopers.

With terrestrial experimentation complete, we have begun executing our mitigation strategy on Mars. On Jan. 12 we did a detailed image survey of the ground below Perseverance. This was done so we would have a good idea what rocks and pebbles already exist down there before some more—from our bit carousel—join them in the not-so-distant future.

With this below-chassis, preliminary imaging, in hand, the team embarked on a maneuver with our I never imagined we would perform—ever. Simply put, we are returning the remaining contents of Sample Tube 261 (our latest cored-) back to its planet of origin. Although this scenario was never designed or planned for prior to launch, it turns out dumping a core from an open tube is a fairly straightforward process (at least during Earth testing). We sent commands up yesterday, and later on today the rover’s robotic arm will simply point the open end of the sample tube toward the surface of Mars and let gravity do the rest.

I imagine your next question is, “Why are you dumping out the contents of the sample tube?” The answer is that, at present, we are not certain how much cored rock continues to reside in Tube 261. And while this rock will never make my holiday card list, the science team really seems to like it. So if our plans go well with our pebble mitigation (see below), we may very well attempt to core “Issole” (the rock from which this sample was taken) again.

Which brings me to next steps in our pebble mitigation strategy: We’re sending up commands to the rover later today ordering it to do two rotation tests of the bit carousel. These tests (the first, a small rotation; the second, larger) will execute this weekend. Our expectations are that these rotations—and any subsequent movement—will help guide our team, providing them the necessary information on how to proceed. Still, to be thorough, we are also commanding the rover to take a second set of under-chassis images, just in case one or more pebbles happen to pop free.

We expect the data and imagery from these two rotation tests to be sent to Earth by next Tuesday, Jan. 18. From there, we’ll analyze and further refine our plans. If I had to ballpark it, I would estimate we’ll be at our current location another week or so—or even more if we decide to re- Issole.

So there you have it. The Perseverance team is exploring every facet of the issue to ensure that we not only get rid of this rocky debris but also prevent a similar reoccurrence during future sampling. Essentially, we are leaving no unturned in the pursuit of these four pebbles.



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Perseverance dumps contents of Sample Tube 261 in first step to clear rocky anomaly (2022, January 19)
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Hexbyte Glen Cove NASA’s Perseverance captures challenging flight by Mars helicopter

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The flight model of NASA’s Ingenuity Mars Helicopter. Credits: NASA/JPL-Caltech

Video footage from NASA’s Perseverance Mars rover of the Ingenuity Mars Helicopter’s 13th flight on Sept. 4 provides the most detailed look yet of the rotorcraft in action.

Ingenuity is currently prepping for its 16th flight, scheduled to take place no earlier than Saturday, Nov. 20, but the 160.5-second Flight 13 stands out as one of Ingenuity’s most complicated. It involved flying into varied terrain within the “Séítah” geological feature and taking images of an outcrop from multiple angles for the rover team. Acquired from an altitude of 26 feet (8 meters), the images complement those collected during Flight 12, providing valuable insight for Perseverance scientists and rover drivers.

Captured by the ‘s two-camera Mastcam-Z, one video clip of Flight 13 shows a majority of the 4-pound (1.8-kilogram) rotorcraft’s flight profile. The other provides a closeup of takeoff and landing, which was acquired as part of a science observation intended to measure the dust plumes generated by the helicopter.

“The value of Mastcam-Z really shines through with these video clips,” said Justin Maki, deputy principal investigator for the Mastcam-Z instrument at NASA’s Jet Propulsion Laboratory in Southern California. “Even at 300 meters [328 yards] away, we get a magnificent closeup of takeoff and landing through Mastcam-Z’s ‘right eye.” And while the helicopter is little more than a speck in the wide view taken through the ‘left eye,” it gives viewers a good feel for the size of the environment that Ingenuity is exploring.”






Video footage from the Mastcam-Z instrument aboard NASA’s Perseverance Mars rover provides a big-picture perspective of the 13th flight of the agency’s Ingenuity Mars Helicopter, on Sept. 4, 2021. Credit: NASA/JPL-Caltech/ASU/MSSS

During takeoff, Ingenuity kicks up a small plume of dust that the right camera, or “eye,” captures moving to the right of the helicopter during ascent. After its initial climb to planned maximum altitude of 26 feet (8 meters), the helicopter performs a small pirouette to line up its color camera for scouting. Then Ingenuity pitches over, allowing the rotors’ thrust to begin moving it horizontally through the thin Martian air before moving offscreen. Later, the rotorcraft returns and lands in the vicinity of where it took off. The team targeted a different landing spot—about 39 feet (12 meters) from takeoff—to avoid a ripple of sand it landed on at the completion of Flight 12.

Though the view from Mastcam-Z’s left eye shows less of the helicopter and more of Mars than the right, the wide angle provides a glimpse of the unique way that the Ingenuity team programmed the flight to ensure success.

“We took off from the floor and flew over an elevated ridgeline before dipping into Séítah,” said Ingenuity Chief Pilot Håvard Grip of JPL. “Since the helicopter’s navigation filter prefers flat terrain, we programmed in a waypoint near the ridgeline, where the helicopter slows down and hovers for a moment. Our flight simulations indicated that this little ‘breather’ would help the helicopter keep track of its heading in spite of the significant terrain variations. It does the same on the way back. It’s awesome to actually get to see this occur, and it reinforces the accuracy of our modeling and our understanding of how to best operate Ingenuity.”






Video from the Mastcam-Z instrument aboard NASA’s Perseverance Mars rover captures a closeup view of the 13th flight of the agency’s Ingenuity Mars Helicopter, on Sept. 4, 2021. Credit: NASA/JPL-Caltech/ASU/MSSS

The wide-angle view also shows how Ingenuity maintains altitude during the flight. After an initial ascent to 26 feet (8 meters) altitude, the helicopter’s notes a change in elevation of the below as it heads northeast toward the ridgeline. Ingenuity automatically adjusts, climbing slightly as it approaches the ridge and then descending to remain 26 feet (8 meters) above the undulating surface. Once it flies to the right, out of view, Ingenuity collects 10 images of the rocky outcrop with its color camera before heading back into frame and returning to land in the targeted location.

After Flight 13, Ingenuity went quiet in October, along with NASA’s other Mars spacecraft during Mars solar conjunction, when the Red Planet and Earth are on opposite sides of the Sun, precluding most communications. Following conjunction, Ingenuity performed a short experimental flight test before undertaking Flight 15, which began the multi- journey back to the vicinity of “Wright Brothers Field,” its starting point back in April.



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NASA’s Perseverance captures challenging flight by Mars helicopter (2021, November 18)
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Hexbyte Glen Cove Twin of NASA’s Perseverance Mars rover begins terrain tests

Hexbyte Glen Cove

Updated with new features, the Earthly twin of NASA’s Perseverance Mars rover arrives at the Mars Yard garage at the agency’s Jet Propulsion Laboratory on Oct. 29, 2021. Credit: NASA/JPL-Caltech

On a recent day in November, the car-size rover rolled slowly forward, then stopped, perched on the threshold of a Martian landscape. But this rover, named OPTIMISM, wasn’t on the Red Planet. And the landscape was a boulder-strewn mock-up of the real Mars—the Mars Yard at NASA’s Jet Propulsion Laboratory in Southern California.

OPTIMISM, a twin of the Perseverance rover that is exploring Jezero Crater on Mars, will perform a crucial job in the weeks ahead: Navigating the Mars Yard’s slopes and hazards, drilling sample cores from boulders, and storing the samples in metal tubes—just like Perseverance is doing in its hunt for signs of ancient microbial life. Short for Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars, OPTIMISM is more generically known as a vehicle system test bed, and the recently upgraded rover begins testing out new equipment for the first time this month.

The tests help ensure that OPTIMISM’s twin on Mars can safely execute the commands sent by controllers on Earth. They also could potentially reveal unexpected problems Perseverance might encounter.

“The size and shape of rocks in the visual field—will they turn into obstacles or not?” said Bryan Martin, the flight software and test beds manager at JPL. “We test a lot of that, figure out what kinds of things to avoid. What we have safely traversed around here has informed rover drivers in planning their traverses on Mars. We’ve done so much testing on the ground we can be confident in it. It works.”

About as long as a doubles tennis court and twice as wide, the Mars Yard has served as a testing ground for many a fully-engineered rover twin—from the engineering model of the very first, tiny Sojourner that landed on Mars in 1997 to the Spirit and Opportunity missions that began in 2004 to the Curiosity and Perseverance rovers exploring Mars today.

In each case, a rover double has scaled slopes, dodged obstacles, or helped rover planners puzzle out new paths on the simulated patch of Mars. OPTIMISM first rolled out into the Mars Yard in September 2020, when it conducted mobility tests.

But it recently received some key updates to match features available on Perseverance, including additional mobility software and the bulk of the exquisitely complex sample caching system. And while the team has already performed tests using the coring drill at the end of OPTIMISM’s robotic arm, they’ll be testing the newly installed Adaptive Caching Assembly for the first time in the Mars Yard. The assembly on Perseverance is responsible for storing rock and sediment samples. Some or all of these initial samples could be among those returned to Earth by a future mission.

“Now we can do it end-to-end in the test bed,” said the Vehicle System Test Bed systems engineering lead, Jose G. Trujillo-Rojas. “Drill into the rock, collect the core sample, and now we have the mechanism responsible to cache that sample in the cylinder.”

And if problems arise on Perseverance on Mars, OPTIMISM can be used as a platform to figure out what went wrong and also how to fix it.

Twin twins

On this November day, a heavy-duty vehicle transported OPTIMISM from a JPL test lab to the Mars Yard garage. Recently expanded, the structure also provides shelter to one of Curiosity’s Earthly counterparts: MAGGIE, or Mars Automated Giant Gizmo for Integrated Engineering. A second Curiosity double, a skeletal version called “Scarecrow” that lacks a computer brain, is housed in a separate shed in the Mars Yard.

MAGGIE would be joining OPTIMISM in the Mars Yard garage in the days ahead.

But, for now, the test-bed crew was focused on OPTIMISM. “Straight 5 meters forward: Ready?” Leann Bowen, a test bed engineer, called out from a computer console inside the garage.

“All right, bring her home, Leann,” Trujillo-Rojas said.

With a whine of electric motors, OPTIMISM crept forward on its six metal wheels, stopping right on the mark on the garage’s concrete floor as members of the team looked on in their white lab coats. Through a wide-open door ahead of the rover, the Mars Yard beckoned.

Drilling core samples from terrestrial rocks in the Mars Yard and sealing them in metal tubes is not as straightforward as it might sound. JPL’s Mars team provides a variety of rock types for OPTIMISM to drill through, since the exact nature of the rock Perseverance will encounter often can’t be known in advance. Terrain is a variable, too: One previous test with the robotic arm involved parking the rover on a slope, then instructing it to drill.

Engineering models of the Curiosity Mars rover (foreground) and the Perseverance Mars rover share space in the garage at JPL’s Mars Yard. Credit: NASA/JPL-Caltech

“There was a possibility that the rover might slip,” Trujillo-Rojas said. “We wanted to test that first here on Earth before sending instructions to the rover on Mars. That was scary, because you can imagine if you drill this way, and the rover slightly slipped back, the drill could have gotten stuck.”

OPTIMISM drilled the core successfully, suggesting Perseverance also could pull off on a slope if required.

Test drive

With longer drives in Perseverance’s near future, another job for the Earth-bound twin will involve presenting new challenges to the rover’s autonomous navigation system, or AutoNav. Perseverance uses a powerful computer to make 3D maps using rover images of the ahead, and uses those maps to plan its drive with minimal human assistance.

In Mars Yard tests, the twin rover might pause as it “thinks through” several possible choices—or even decides, unexpectedly, to avoid altogether and just go around.

“Seeing the rover autonomously move in the Mars Yard, you kind of get that sense of being connected to the rover on Mars,” he said. “It gives you that visual connection.”

Of course, OPTIMISM and its human team must contend with environmental factors very different from those encountered by Perseverance, which is built for freezing temperatures and intense radiation. Earth’s stronger gravity required OPTIMISM’s metal wheels to be thicker than its Martian counterpart’s. And its electronics sometimes must be cooled to avoid damage from Southern California’s summer temperatures—the opposite of the problem caused by deep cold on Mars.

“On Mars, we try to keep the rover warm,” Trujillo-Rojas said. “Here, we’re trying to keep it cool.”

Deer, bobcats, tarantulas, even occasional snakes, find their way into the Mars Yard. Wildfire in the region can fill the air with smoke. And testing and staffing schedules had to contend with COVID-19.

“We’ve been through a lot of challenges with this rover,” he said. “As soon as we were going to start building it, with hands-on integration, the pandemic happened. And then we had rains, and we got a lot of fire. We had to leave the lab—smoky!”

Now, a revamped OPTIMISM is ready to get back to work.

“It’s a big milestone for our team,” Trujillo-Rojas said.

More about the mission

A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.



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For more about Perseverance, visit mars.nasa.gov/mars2020/ and nasa.gov/perseverance

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Hexbyte Glen Cove Perseverance Mars Rover to acquire first sample thumbnail

Hexbyte Glen Cove Perseverance Mars Rover to acquire first sample

Hexbyte Glen Cove

A light-colored “paver stone” like the ones seen in this mosaic will be the likely target for first sampling by the Perseverance rover. The image was taken on July 8, 2021 in the “Cratered Floor Fractured Rough” geologic unit at Jezero Crater. Credit: NASA/JPL-Caltech/ASU/MSSS

NASA is making final preparations for its Perseverance Mars rover to collect its first-ever sample of Martian rock, which future planned missions will transport to Earth. The six-wheeled geologist is searching for a scientifically interesting target in a part of Jezero Crater called the “Cratered Floor Fractured Rough.”

This important mission milestone is expected to begin within the next two weeks. Perseverance landed in Jezero Crater on Feb. 18, and NASA kicked off the rover mission’s science phase June 1, exploring a 1.5-square-mile (4-square-kilometer) patch of crater floor that may contain Jezero’s deepest and most ancient layers of exposed bedrock.

“When Neil Armstrong took the first sample from the Sea of Tranquility 52 years ago, he began a process that would rewrite what humanity knew about the Moon,” said Thomas Zurbuchen, associate administrator for science at NASA Headquarters. “I have every expectation that Perseverance’s first sample from Jezero Crater, and those that come after, will do the same for Mars. We are on the threshold of a new era of planetary science and discovery.”

It took Armstrong 3 minutes and 35 seconds to collect that first Moon sample. Perseverance will require about 11 days to complete its first sampling, as it must receive its instructions from hundreds of millions of miles away while relying on the most complex and capable, as well as the cleanest, mechanism ever to be sent into space—the Sampling and Caching System.






Watch as NASA-JPL engineers test the Sample Caching System on the Perseverance Mars rover. Described as one of the most complex robotic systems ever built, the Sample and Caching System will collect core samples from the rocky surface of Mars, seal them in tubes and leave them for a future mission to retrieve and bring back to Earth. Credit: NASA-JPL/Caltech

Precision instruments working together

The sampling sequence begins with the rover placing everything necessary for sampling within reach of its 7-foot-long (2-meter-long) robotic arm. It will then perform an imagery survey, so NASA’s science team can determine the exact location for taking the first sample and a separate target site in the same area for “proximity science.”

“The idea is to get valuable data on the rock we are about to sample by finding its geologic twin and performing detailed in-situ analysis,” said science campaign co-lead Vivian Sun, from NASA’s Jet Propulsion Laboratory in Southern California. “On the geologic double, first we use an abrading bit to scrape off the top layers of rock and dust to expose fresh, unweathered surfaces, blow it clean with our Gas Dust Removal Tool, and then get up close and personal with our turret-mounted proximity science instruments SHERLOC, PIXL, and WATSON.”

SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals), PIXL (Planetary Instrument for X-ray Lithochemistry), and the WATSON (Wide Angle Topographic Sensor for Operations and eNgineering) camera will provide mineral and chemical analysis of the abraded target.

Perseverance’s SuperCam and Mastcam-Z instruments, both located on the rover’s mast, will also participate. While SuperCam fires its laser at the abraded surface, spectroscopically measuring the resulting plume and collecting other data, Mastcam-Z will capture high-resolution imagery.

Working together, these five instruments will enable unprecedented analysis of geological materials at the worksite.

“After our pre-coring science is complete, we will limit rover tasks for a sol, or a Martian day,” said Sun. “This will allow the rover to fully charge its battery for the events of the following day.”

Sampling day kicks off with the sample-handling arm within the Adaptive Caching Assembly retrieving a sample tube, heating it, and then inserting it into a coring bit. A device called the bit carousel transports the tube and bit to a rotary-percussive drill on Perseverance’s robotic arm, which will then drill the untouched geologic “twin” of the studied the previous sol, filling the tube with a core sample roughly the size of a piece of chalk.

Perseverance’s arm will then move the bit-and-tube combination back into bit carousel, which will transfer it back into the Adaptive Caching Assembly, where the sample will be measured for volume, photographed, hermetically sealed, and stored. The next time the sample tube contents are seen, they will be in a clean room facility on Earth, for analysis using scientific instruments much too large to send to Mars.

“Not every sample Perseverance is collecting will be done in the quest for ancient life, and we don’t expect this first sample to provide definitive proof one way or the other,” said Perseverance project scientist Ken Farley, of Caltech. “While the rocks located in this geologic unit are not great time capsules for organics, we believe they have been around since the formation of Jezero Crater and incredibly valuable to fill gaps in our geologic understanding of this region—things we’ll desperately need to know if we find life once existed on Mars.”



More information:
To learn more about Perseverance, visit: nasa.gov/perseverance and mars.nasa.gov/mars2020/

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Perseverance Mars Rover to acquire first sample (2021, July 21)
retrieved 22 July 2021
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