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NASA’s Mars Helicopter Reveals Intriguing Terrain for Rover Team Ingenuity’s ninth flight provided imagery that will help the Perseverance rover team develop its science plan going forward. Images snapped on July 5 by NASA’s Ingenuity Mars Helicopter on its ambitious ninth flight have offered scientists and engineers working with the agency’s Perseverance Mars rover an unprecedented opportunity to scout out the road ahead. Ingenuity provided new insight into where different rock layers begin and end, each layer serving as a time capsule for how conditions in the ancient climate changed at this location. The flight also revealed obstacles the rover may have to drive around as it explores Jezero Crater. During the flight – designed to test the helicopter’s ability to serve as an aerial scout – Ingenuity soared over a dune field nicknamed “Séítah.” Perseverance is making a detour south around those dunes, which would be too risky for the six-wheeled rover to try crossing. The color images from Ingenuity, taken from a height of around 33 feet (10 meters), offer the rover team much greater detail than they get from the orbiter images they typically use for route planning. While a camera like HiRISE (the High Resolution Imaging Science Experiment) aboard NASA’s Mars Reconnaissance Orbiter can resolve rocks about 3 feet (1 meter) in diameter, missions usually rely on rover images to see smaller rocks or terrain features. “Once a rover gets close enough to a location, we get ground-scale images that we can compare to orbital images,” said Perseverance Deputy Project Scientist Ken Williford of NASA’s Jet Propulsion Laboratory in Southern California. “With Ingenuity, we now have this intermediate-scale imagery that nicely fills the gap in resolution.” Raised Ridges Ingenuity (its shadow is visible at the bottom of this image) offered a high-resolution glimpse of rock features nicknamed “Raised Ridges.” They belong to a fracture system, which often serve as pathways for fluid to flow underground. Here in Jezero Crater, a lake existed billions of years ago. Spying the ridges in images from Mars orbiters, scientists have wondered whether water might have flowed through these fractures at some point, dissolving minerals that could help feed ancient microbial colonies. That would make them a prime location to look for signs of ancient life – and perhaps to drill a sample. The samples Perseverance takes will eventually be deposited on Mars for a future mission that would take them to Earth for in-depth analysis. “Our current plan is to visit Raised Ridges and investigate it close up,” Williford said. “The helicopter’s images are by far better in resolution than the orbital ones we were using. Studying these will allow us to ensure that visiting these ridges is important to the team.” Dunes Sand dunes like the ones in this image keep rover drivers like JPL’s Olivier Toupet awake at night: Knee- or waist-high, they could easily cause the two-ton rover to get stuck. After landing in February, Perseverance scientists asked whether it was possible to make a beeline across this terrain; Toupet’s answer was a hard no. “Sand is a big concern,” said Toupet, who leads the team of mobility experts that plans Perseverance’s drives. “If we drive downhill into a dune, we could embed ourselves into it and not be able to get back out.” Toupet is also the lead for Perseverance’s newly tested AutoNav feature, which uses artificial intelligence algorithms to drive the rover autonomously over greater distances than could be achieved otherwise. While good at avoiding rocks and other hazards, AutoNav can’t detect sand, so human drivers still need to define “keep-out zones” around areas that could entrap the rover. Bedrock Without Ingenuity, visible in silhouette at the bottom of this next image, Perseverance’s scientists would never get to see this section of Séítah so clearly: It’s too sandy for Perseverance to visit. The unique view offers enough detail to inspect these rocks and get a better understanding of this area of Jezero Crater. As the rover works its way around the dune field, it may make what the team calls a “toe dip” into some scientifically compelling spots with interesting bedrock. While Toupet and his team wouldn’t attempt a toe dip here, the recent images from Ingenuity will allow them to plan potential toe-dip paths in other regions along the route of Perseverance’s first science campaign. “The helicopter is an extremely valuable asset for rover planning because it provides high-resolution imagery of the terrain we want to drive through,” said Toupet. “We can better assess the size of the dunes and where bedrock is poking out. That’s great information for us; it helps identify which areas may be traversable by the rover and whether certain high-value science targets are reachable.” 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. The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet. JPL, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover. The Ingenuity Mars Helicopter was built by JPL, which also manages the technology demonstration project for NASA Headquarters. It is supported by NASA’s Science, Aeronautics Research, and Space Technology mission directorates. NASA’s Ames Research Center in California’s Silicon Valley, and NASA’s Langley Research Center in Hampton, Virginia, provided significant flight performance analysis and technical assistance during Ingenuity’s development. AeroVironment Inc., Qualcomm, and SolAero also provided design assistance and major vehicle components. Lockheed Martin Space designed and manufactured the Mars Helicopter Delivery System. JPL manages the MRO mission for NASA's Science Mission Directorate in Washington. The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. For more about Perseverance: mars.nasa.gov/mars2020/ nasa.gov/perseverance

 

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Surface of Jupiter’s Moon Europa Churned by Small Impacts Jupiter’s moon Europa and its global ocean may currently have conditions suitable for life. Scientists are studying processes on the icy surface as they prepare to explore. It’s easy to see the impact of space debris on our Moon, where the ancient, battered surface is covered with craters and scars. Jupiter’s icy moon Europa withstands a similar trouncing – along with a punch of super-intense radiation. As the uppermost surface of the icy moon churns, material brought to the surface is zapped by high-energy electron radiation accelerated by Jupiter. NASA-funded scientists are studying the cumulative effects of small impacts on Europa’s surface as they prepare to explore the distant moon with the Europa Clipper mission and study the possibilities for a future lander mission. Europa is of particular scientific interest because its salty ocean, which lies beneath a thick layer of ice, may currently have conditions suitable for existing life. That water may even make its way into the icy crust and onto the moon’s surface. “If we hope to find pristine, chemical biosignatures, we will have to look below the zone where impacts have been gardening,” said lead author Emily Costello, a planetary research scientist at the University of Hawaii at Manoa. “Chemical biosignatures in areas shallower than that zone may have been exposed to destructive radiation.” Going Deeper While impact gardening has long been understood to be likely taking place on Europa and other airless bodies in the solar system, the new modeling provides the most comprehensive picture yet of the process. In fact, it is the first to take into account secondary impacts caused by debris raining back down onto Europa’s surface after being kicked up by an initial impact. The research makes the case that Europa’s mid- to high-latitudes would be less affected by the double whammy of impact gardening and radiation. “This work broadens our understanding of the fundamental processes on surfaces across the solar system,” said Cynthia Phillips, a Europa scientist at NASA’s Jet Propulsion Laboratory in Southern California and a co-author of the study. “If we want to understand the physical characteristics and how planets in general evolve, we need to understand the role impact gardening has in reshaping them.” Managed by JPL for NASA, Europa Clipper will help develop that understanding. The spacecraft, targeting a 2024 launch, will conduct a series of close flybys of Europa as it orbits Jupiter. It will carry instruments to thoroughly survey the moon, as well as sample the dust and gases that are kicked up above the surface. More About the Mission Missions such as Europa Clipper contribute to the field of astrobiology, the interdisciplinary research on the variables and conditions of distant worlds that could harbor life as we know it. While Europa Clipper is not a life-detection mission, it will conduct detailed reconnaissance of Europa and investigate whether the icy moon, with its subsurface ocean, has the capability to support life. Understanding Europa’s habitability will help scientists better understand how life developed on Earth and the potential for finding life beyond our planet. Managed by Caltech in Pasadena, California, JPL leads the development of the Europa Clipper mission in partnership with APL for NASA’s Science Mission Directorate in Washington. The Planetary Missions Program Office at NASA’s Marshall Space Flight Center in Huntsville, Alabama, executes program management of the Europa Clipper mission. More information about Europa can be found here: europa.nasa.gov

 

 

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Seeing Some Cosmic X-Ray Emitters Might Be a Matter of Perspective Known as ultraluminous X-ray sources, the emitters are easy to spot when viewed straight on, but they might be hidden from view if they point even slightly away from Earth. It’s hard to miss a flashlight beam pointed straight at you. But that beam viewed from the side appears significantly dimmer. The same holds true for some cosmic objects: Like a flashlight, they radiate primarily in one direction, and they look dramatically different depending on whether the beam points away from Earth (and nearby space telescopes) or straight at it. New data from NASA’s NuSTAR space observatory indicates that this phenomenon holds true for some of the most prominent X-ray emitters in the local universe: ultraluminous X-ray sources, or ULXs. Most cosmic objects, including stars, radiate little X-ray light, particularly in the high-energy range seen by NuSTAR. ULXs, by contrast, are like X-ray lighthouses cutting through the darkness. To be considered a ULX, a source must have an X-ray luminosity that is about a million times brighter than the total light output of the Sun (at all wavelengths). ULXs are so bright, they can be seen millions of light-years away, in other galaxies. The new study shows that the object known as SS 433, located in the Milky Way galaxy and only about 20,000 light-years from Earth, is a ULX, even though it appears to be about 1,000 times dimmer than the minimum threshold to be considered one. This faintness is a trick of perspective, according to the study: The high-energy X-rays from SS 433 are initially confined within two cones of gas extending outward from opposite sides of the central object. These cones are similar to a mirrored bowl that surrounds a flashlight bulb: They corral the X-ray light from SS 433 into a narrow beam, until it escapes and is detected by NuSTAR. But because the cones are not pointing directly at Earth, NuSTAR can’t see the object’s full brightness. Cone of Darkness About 500 ULXs have been found in other galaxies, and their distance from Earth means it’s often nearly impossible to tell what type of object generates the X-ray emission. The X-rays likely come from a large amount of gas being heated to extreme temperatures as it is pulled in by the gravity of a very dense object. That object could be either a neutron star (the remains of a collapsed star) or a small black hole, one that is no more than about 30 times the mass of our Sun. The gas forms a disk around the object, like water circling a drain. Friction in the disk drives up the temperature, causing it to radiate, sometimes growing so hot that the system erupts with X-rays. The faster the material falls onto the central object, the brighter the X-rays. Astronomers suspect that the object at the heart of SS 433 is a black hole about 10 times the mass of our Sun. What’s known for sure is that it is cannibalizing a large nearby star, its gravity siphoning away material at a rapid rate: In a single year SS 433 steals the equivalent of about 30 times the mass of Earth from its neighbor, which makes it the greediest black hole or neutron star known in our galaxy. “It’s been known for a long time that this thing is eating at a phenomenal rate,” said Middleton. “This is what sets ULXs apart from other objects, and it’s likely the root cause of the copious amounts of X-rays we see from them.” The object in SS 433 has eyes bigger than its stomach: It’s stealing more material than it can consume. Some of the excess material gets blown off the disk and forms two hemispheres on opposite sides of the disk. Within each one is a cone-shaped void that opens up into space. These are the cones that corral the high-energy X-ray light into a beam. Anyone looking straight down one of the cones would see an obvious ULX. Though composed only of gas, the cones are so thick and massive that they act like lead paneling in an X-ray screening room and block X-rays from passing through them out to the side. Scientists have suspected that some ULXs might be hidden from view for this reason. SS 433 provided a unique chance to test this idea because, like a top, it wobbles on its axis – a process astronomers call precession. Most of the time, both of SS 433’s cones point well away from Earth. But because of the way SS 433 precesses, one cone periodically tilts slightly toward Earth, so scientists can see a little bit of the X-ray light coming out of the top of the cone. In the new study, the scientists looked at how the X-rays seen by NuSTAR change as SS 433 moves. They show that if the cone continued to tilt toward Earth so that scientists could peer straight down it, they would see enough X-ray light to officially call SS 433 a ULX. Black holes that feed at extreme rates have shaped the history of our universe. Supermassive black holes, which are millions to billions of times the mass of the Sun, can profoundly affect their host galaxy when they feed. Early in the universe’s history, some of these massive black holes may have fed as fast as SS 433, releasing huge amounts of radiation that reshaped local environments. Outflows (like the cones in SS 433) redistributed matter that could eventually form stars and other objects. But because these quickly consuming behemoths reside in incredibly distant galaxies (the one at the heart of the Milky Way isn’t currently eating much), they remain difficult to study. With SS 433, scientists have found a miniature example of this process, much closer to home and much easier to study, and NuSTAR has provided new insights into the activity occurring there. “When we launched NuSTAR, I don’t think anyone expected that ULXs would be such a rich area of research for us,” said Fiona Harrison, principal investigator for NuSTAR and a professor of physics at Caltech in Pasadena, California. “But NuSTAR is unique in that it can see almost the whole range of X-ray wavelengths emitted by these objects, and that gives us insight into the extreme processes that must be driving them.” More About the Mission NuSTAR is a Small Explorer mission led by Caltech and managed by NASA’s Jet Propulsion Laboratory, a division of Caltech, for the agency’s Science Mission Directorate in Washington. NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corporation in Dulles, Virginia (now part of Northrop Grumman). NuSTAR’s mission operations center is at the University of California, Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center. ASI provides the mission’s ground station and a mirror archive. For more information about NuSTAR, visit: https://www.nasa.gov/mission_pages/nustar/main/index.html https://www.nustar.caltech.edu/

 

LATEST NEWS NASA’s Curiosity Rover Finds Patches of Rock Record Erased, Revealing Clues A new paper enriches scientists’ understanding of where the rock record preserved or destroyed evidence of Mars’ past and possible signs of ancient life. Today, Mars is a planet of extremes – it’s bitterly cold, has high radiation, and is bone-dry. But billions of years ago, Mars was home to lake systems that could have sustained microbial life. As the planet’s climate changed, one such lake – in Mars’ Gale Crater – slowly dried out. Scientists have new evidence that supersalty water, or brines, seeped deep through the cracks, between grains of soil in the parched lake bottom and altered the clay mineral-rich layers beneath. The findings published in the July 9 edition of the journal Science and led by the team in charge of the Chemistry and Mineralogy, or CheMin, instrument – aboard NASA’s Mars Science Laboratory Curiosity rover – help add to the understanding of where the rock record preserved or destroyed evidence of Mars’ past and possible signs of ancient life. “We used to think that once these layers of clay minerals formed at the bottom of the lake in Gale Crater, they stayed that way, preserving the moment in time they formed for billions of years,” said Tom Bristow, CheMin principal investigator and lead author of the paper at NASA’s Ames Research Center in California’s Silicon Valley. “But later brines broke down these clay minerals in some places – essentially resetting the rock record.” Mars: It Goes on Your Permanent Record Mars has a treasure trove of incredibly ancient rocks and minerals compared with Earth. And with Gale Crater’s undisturbed layers of rocks, scientists knew it would be an excellent site to search for evidence of the planet’s history, and possibly life. Using CheMin, scientists compared samples taken from two areas about a quarter-mile apart from a layer of mudstone deposited billions of years ago at the bottom of the lake at Gale Crater. Surprisingly, in one area, about half the clay minerals they expected to find were missing. Instead, they found mudstones rich with iron oxides – minerals that give Mars its characteristic rusty red color. Scientists knew the mudstones sampled were about the same age and started out the same – loaded with clays – in both areas studied. So why then, as Curiosity explored the sedimentary clay deposits along Gale Crater, did patches of clay minerals – and the evidence they preserve – “disappear”? Clays Hold Clues Minerals are like a time capsule; they provide a record of what the environment was like at the time they formed. Clay minerals have water in their structure and are evidence that the soils and rocks that contain them came into contact with water at some point. “Since the minerals we find on Mars also form in some locations on Earth, we can use what we know about how they form on Earth to tell us about how salty or acidic the waters on ancient Mars were,” said Liz Rampe, CheMin deputy principal investigator and co-author at NASA’s Johnson Space Center in Houston. Previous work revealed that while Gale Crater’s lakes were present and even after they dried out, groundwater moved below the surface, dissolving and transporting chemicals. After they were deposited and buried, some mudstone pockets experienced different conditions and processes due to interactions with these waters that changed the mineralogy. This process, known as “diagenesis,” often complicates or erases the soil’s previous history and writes a new one. Diagenesis creates an underground environment that can support microbial life. In fact, some very unique habitats on Earth – in which microbes thrive – are known as “deep biospheres.” “These are excellent places to look for evidence of ancient life and gauge habitability,” said John Grotzinger, CheMin co-investigator and co-author at the California Institute of Technology, or Caltech, in Pasadena, California. “Even though diagenesis may erase the signs of life in the original lake, it creates the chemical gradients necessary to support subsurface life, so we are really excited to have discovered this.” By comparing the details of minerals from both samples, the team concluded that briny water filtering down through overlying sediment layers was responsible for the changes. Unlike the relatively freshwater lake present when the mudstones formed, the salty water is suspected to have come from later lakes that existed within an overall drier environment. Scientists believe these results offer further evidence of the impacts of Mars’ climate change billions of years ago. They also provide more detailed information that is then used to guide the Curiosity rover’s investigations into the history of the Red Planet. This information also will be utilized by NASA’s Mars 2020 Perseverance rover team as they evaluate and select rock samples for eventual return to Earth. “We’ve learned something very important: There are some parts of the Martian rock record that aren’t so good at preserving evidence of the planet’s past and possible life,” said Ashwin Vasavada, Curiosity project scientist and co-author at NASA’s Jet Propulsion Laboratory in Southern California. “The fortunate thing is we find both close together in Gale Crater, and can use mineralogy to tell which is which.” Curiosity is in the initial phase of investigating the transition to a “sulfate-bearing unit,” or rocks thought to have formed while Mars’ climate dried out. The mission is managed by JPL, a division of Caltech, for NASA’s Science Mission Directorate, Washington. Colleagues in NASA’s Astromaterials Research and Exploration Science Division at Johnson and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, also are authors on the paper, as well as other institutions working on Curiosity.

 

LATEST NEWS Meet the Open-Source Software Powering NASA’s Ingenuity Mars Helicopter Created at NASA’s JPL, the open-source flight software called F Prime isn’t just powering humanity’s first interplanetary helicopter; it’s also powering inspiration at multiple universities. When NASA’s Ingenuity Mars Helicopter hovered above the Red Planet April 19 on its maiden voyage, the moment was hailed as the first instance of powered, controlled flight on another planet. Figuring out how to fly on Mars, where the air is thin but gravity is about a third of that on Earth, took years of work. Along with the challenge of developing a craft that was up to the task, the mission needed software to make the unprecedented flights possible. So they turned to F Prime, a reusable, multi-mission flight software framework designed for CubeSats, small spacecraft, and instruments. The program was initially developed in 2013 by a team led by Tim Canham at NASA’s Jet Propulsion Laboratory in Southern California with the aim of creating a low-cost, portable, pliable software architecture option that would allow components written for one application to be reused easily in other applications and run on a range of processors. In 2017, the team pushed for F Prime to be released as open-source, meaning anyone could freely access the software’s source code, allowing external collaborators, universities, and the general public to use the framework on their own projects. It is one of hundreds of codes NASA makes available to the public for free, both as open-source or through its software catalog. “F Prime has enabled a lot of goals we’ve had at JPL to design a truly reusable multi-mission flight architecture with the added bonus of the open-source collaboration and visibility afforded by the Mars Helicopter project,” Canham said. “It’s kind of an open-source victory, because we’re flying an open-source operating system and an open-source flight software framework, and flying commercial parts that you can buy off the shelf, if you wanted to do this yourself someday.” (The helicopter carries a combination of custom-made and off-the-shelf components – many from the world of cell phone technology – including its two cameras.) Before Ingenuity, F Prime (also written as F’) had already been put through its spacecraft paces, operating successfully aboard the ISS RapidScat scatterometer instrument on the International Space Station since 2014 and JPL’s ASTERIA CubeSat in 2017. Looking forward, F Prime is scheduled to run on projects including NASA’s Lunar Flashlight CubeSat, which will look for surface ice in the Moon’s craters; the agency’s Near-Earth Asteroid Scout CubeSat, which will map an asteroid; and potentially JPL’s Ocean Worlds Life Surveyor instrument, which would help search for water-based life in our solar system. Aadil Rizvi, flight software lead for Lunar Flashlight and NEA Scout at JPL, says F Prime provides an out-of-the-box solution for several flight software services, such as commanding, telemetry, parameters, and sequencing for the spacecraft. There’s also a sort of “auto-coding” tool that makes F Prime highly portable for use across missions. “This makes it quite easy to drop in a software component from something like Mars Helicopter into another mission’s flight software such as Lunar Flashlight or make the component available for open-source use by anyone else using F Prime,” Rizvi said. “And it’s pretty cool that a significant portion of software used on the Mars Helicopter is identical to software on another spacecraft going to the Moon, or an asteroid, or sitting on a student’s desk.” Universities See the Benefits of F Prime Since its open-source debut, F Prime has gradually begun gaining traction as a useful flight software option for university and student projects. At Georgia Tech, a team has incorporated F Prime in its GT1 CubeSat, aimed to serve as an education exercise that will carry an interactive and automatic amateur radio payload. “We chose F Prime after evaluating a handful of flight software frameworks, including the option of writing our own from scratch,” said Sterling Peet, Georgia Tech research faculty member and software lead for GT1. “We don’t have the resources to build all this code from scratch, use, and test it to ensure the necessary levels of reliability in-house. But by using F Prime, we can leverage the legacy it has and also contribute our testing and related benefits back to the F Prime community and project.” A Carnegie Mellon University student-led team chose F Prime to run its Iris Lunar Rover, a tiny robot designed to prove the feasibility of nano-rovers in planetary exploration. “It was a viable option with a direct link to the creators, so we decided to use it ourselves,” said Iris Deputy Program Manager Raewyn Duvall. F Prime will control the rover while recording data and monitoring its health. “The fact that it is open-source gave us a wide range of examples to base our own modules and let us use the forum to get quick answers without having to worry about potential support service charges just to get answers to questions we may have had,” Duvall said. JPL Small Scale Flight Software Group Supervisor Jeff Levison sees university partnerships like the ones with Georgia Tech and Carnegie Mellon as a two-way street: JPL provides world-leading flight systems expertise to budding engineers, and then down the line, those future engineers could end up bringing their talents and a working understanding of F Prime to start a career at JPL. “F Prime is not an easy architecture to pick up, so a student who manages to master it and create a solid working project clearly has amazing potential for an organization like JPL,” said Carnegie Mellon’s Duvall. “Many of our students working on Iris that learned F Prime have expressed interest in applying to JPL, which I believe proves F Prime’s worth as a recruitment tool.”

 

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NASA’s Self-Driving Perseverance Mars Rover ‘Takes the Wheel’ The agency’s newest rover is trekking across the Martian landscape using a newly enhanced auto-navigation system. NASA’s newest six-wheeled robot on Mars, the Perseverance rover, is beginning an epic journey across a crater floor seeking signs of ancient life. That means the rover team is deeply engaged with planning navigation routes, drafting instructions to be beamed up, even donning special 3D glasses to help map their course. But increasingly, the rover will take charge of the drive by itself, using a powerful auto-navigation system. Called AutoNav, this enhanced system makes 3D maps of the terrain ahead, identifies hazards, and plans a route around any obstacles without additional direction from controllers back on Earth. “We have a capability called ‘thinking while driving,’” said Vandi Verma, a senior engineer, rover planner, and driver at NASA’s Jet Propulsion Laboratory in Southern California. “The rover is thinking about the autonomous drive while its wheels are turning.” That capability, combined with other improvements, might enable Perseverance to hit a top speed of 393 feet (120 meters) per hour; its predecessor, Curiosity, equipped with an earlier version of AutoNav, covers about 66 feet (20 meters) per hour as it climbs Mount Sharp to the southeast. “We sped up AutoNav by four or five times,” said Michael McHenry, the mobility domain lead and part of JPL’s team of rover planners. “We’re driving a lot farther in a lot less time than Curiosity demonstrated.” As Perseverance begins its first science campaign on the floor of Jezero Crater, AutoNav will be a key feature in helping get the job done. This crater once was a lake, when, billions of years ago, Mars was wetter than today, and Perseverance’s destination is a dried-out river delta at the crater’s edge. If life ever took hold on early Mars, signs of it might be found there. The rover will gather samples over some 9 miles (15 kilometers), then prep the samples for collection by a future mission that would take them back to Earth for analysis. “We’re going to be able to get to places the scientists want to go much more quickly,” said Jennifer Trosper, who has worked on every one of NASA’s Martian rovers and is the Mars 2020 Perseverance rover project manager. “Now we are able to drive through these more complex terrains instead of going around them: It’s not something we’ve been able to do before.” The Human Element Of course, Perseverance can’t get by on AutoNav alone. The involvement of the rover team remains critical in planning and driving Perseverance’s route. An entire team of specialists develops a navigation route along with planning the rover’s activity, whether it’s examining a geologically interesting feature on the way to its destination or, soon, taking samples. Because of the radio signal delay between Earth and Mars, they can’t simply move the rover forward with a joystick. Instead, they scrutinize satellite images, sometimes donning those 3D glasses to view the Martian surface in the rover’s vicinity. Once the team signs off, they beam the instructions to Mars, and the rover executes those instructions the following day. Perseverance’s wheels were modified as well to help with just how swiftly those plans are executed: Along with being slightly greater in diameter and narrower than Curiosity’s wheels, they each feature 48 treads that look like slightly wavy lines, as opposed to Curiosity’s 24 chevron-pattern treads. The goals were to help with traction as well as durability. “Curiosity couldn’t AutoNav because of the wheel-wear issue,” Trosper said. “Early in the mission, we experienced small, sharp, pointy rocks starting to put holes in the wheels, and our AutoNav didn’t avoid those.” Higher clearance for Perseverance’s belly also enables the rover to roll safely over rougher ground – including good-size rocks. And Perseverance’s beefed-up auto-navigation capabilities include ENav, or enhanced navigation, an algorithm-and-software combination that allows more precise hazard detection. Unlike its predecessors, Perseverance can employ one of its computers just for navigation on the surface; its main computer can devote itself to the many other tasks that keep the rover healthy and active. This Vision Compute Element, or VCE, guided Perseverance to the Martian surface during its entry, descent, and landing in February. Now it’s being used full-time to map out the rover’s journey while helping it avoid trouble along the way. The rover also keeps track of how far it’s moved from one spot to another using a system called “visual odometry.” Perseverance periodically captures images as it moves, comparing one position to the next to see if it moved the expected distance. Team members say they look forward to letting AutoNav “take the wheel.” But they’ll also be ready to intervene when needed. And just what is it like to drive on Mars? The planners and drivers say it never gets old. “Jezero is incredible,” Verma said. “It’s a rover driver’s paradise. When you put on the 3D glasses, you see so much more undulation in the terrain. Some days I just stare at the images.”

 

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Asteroid-Hunting Space Telescope Gets Two-Year Mission Extension NEOWISE has provided an estimate of the size of over 1,850 near-Earth objects, helping us better understand our nearest solar system neighbors. For two more years, NASA’s Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) will continue its hunt for asteroids and comets – including objects that could pose a hazard to Earth. This mission extension means NASA’s prolific near-Earth object (NEO) hunting space telescope will continue operations until June 2023. “At NASA, we’re always looking up, surveying the sky daily to find potential hazards and exploring asteroids to help unlock the secrets of the formation of our solar system,” said NASA Administrator Bill Nelson. “Using ground-based telescopes, over 26,000 near-Earth asteroids have already been discovered, but there are many more to be found. We’ll enhance our observations with space-based capabilities like NEOWISE and the future, much more capable NEO Surveyor to find the remaining unknown asteroids more quickly and identify potentially-hazardous asteroids and comets before they are a threat to us here on Earth.” Originally launched as the Wide-field Infrared Survey Explorer (WISE) mission in December 2009, the space telescope surveyed the entire sky in infrared wavelengths, detecting asteroids, dim stars, and some of the faintest galaxies visible in deep space. WISE completed its primary mission when it depleted its cryogenic coolant and it was put into hibernation in February 2011. Observations resumed in December 2013 when the space telescope was repurposed by NASA’s Planetary Science Division as “NEOWISE” to identify asteroids and comets throughout the solar system, with special attention to those that pass close to Earth’s orbit. “NEOWISE provides a unique and critical capability in our global mission of planetary defense, by allowing us to rapidly measure the infrared emission and more accurately estimate the size of hazardous asteroids as they are discovered,” said Lindley Johnson, NASA’s Planetary Defense Officer and head of the Planetary Defense Coordination Office (PDCO) at NASA Headquarters in Washington. “Extending NEOWISE’s mission highlights not only the important work that is being done to safeguard our planet, but also the valuable science that is being collected about the asteroids and comets further out in space.” As asteroids are heated by the Sun, they warm up and release this heat as faint infrared radiation. By studying this infrared signature, scientists can reveal the size of an asteroid and compare it to the measurements of observations made by optical telescopes on the ground. This information can help us understand how reflective its surface is while also providing clues as to its composition. To date, NEOWISE has provided an estimate of the size of over 1,850 NEOs, helping us better understand our nearest solar system neighbors. As of March 2021, the mission had made 1,130,000 confirmed infrared observations of approximately 39,100 objects throughout the solar system since its restart in 2013. Mission data is shared freely by the IPAC/Caltech-led archive, and the data has contributed to over 1,600 peer-reviewed studies. The University of Arizona is also a key partner of the NEOWISE mission as the home institution of the NEOWISE principal investigator, Amy Mainzer, who is a professor of planetary science at the University’s Lunar and Planetary Laboratory. Among its many accomplishments after its reactivation, NEOWISE also discovered Comet NEOWISE, which was named after the mission and dazzled observers worldwide in 2020. NEOWISE’s replacement, the next-generation NEO Surveyor, is currently scheduled to launch in 2026, and will greatly expand on what we have learned, and continue to learn, from NEOWISE. “NEOWISE has taught us a lot about how to find, track, and characterize Earth-approaching asteroids and comets using a space-based infrared telescope,” said Mainzer. “The mission serves as an important precursor for carrying out a more comprehensive search for these objects using the new telescope we’re building, the NEO Surveyor.” Mainzer is also the lead of the NEO Surveyor mission. The NEOWISE project is managed by NASA’s Jet Propulsion Laboratory in Southern California, a division of Caltech, and the University of Arizona, supported by NASA’s PDCO. For more information about NEOWISE, visit: https://www.nasa.gov/neowise http://neowise.ipac.caltech.edu/ For more information about NASA's Planetary Defense Coordination Office, visit: https://www.nasa.gov/planetarydefense

 

LATEST NEWS Deep Space Atomic Clock Moves Toward Increased Spacecraft Autonomy Designed to improve navigation for robotic explorers and the operation of GPS satellites, the technology demonstration reports a significant milestone. Spacecraft that venture beyond our Moon rely on communication with ground stations on Earth to figure out where they are and where they’re going. NASA’s Deep Space Atomic Clock is working toward giving those far-flung explorers more autonomy when navigating. In a new paper published today in the journal Nature, the mission reports progress in their work to improve the ability of space-based atomic clocks to measure time consistently over long periods. Known as stability, this feature also impacts the operation of GPS satellites that help people navigate on Earth, so this work also has the potential to increase the autonomy of next-generation GPS spacecraft. To calculate the trajectory of a distant spacecraft, engineers send signals from the spacecraft to Earth and back. They use refrigerator-size atomic clocks on the ground to log the timing of those signals, which is essential for precisely measuring the spacecraft’s position. But for robots on Mars or more distant destinations, waiting for the signals to make the trip can quickly add up to tens of minutes or even hours. If those spacecraft carried atomic clocks, they could calculate their own position and direction, but the clocks would have to be highly stable. GPS satellites carry atomic clocks to help us get to our destinations on Earth, but those clocks require updates several times a day to maintain the necessary level of stability. Deep space missions would require more stable space-based clocks. Managed by NASA’s Jet Propulsion Laboratory in Southern California, the Deep Space Atomic Clock has been operating aboard General Atomic’s Orbital Test Bed spacecraft since June 2019. The new study reports that the mission team has set a new record for long-term atomic clock stability in space, reaching more than 10 times the stability of current space-based atomic clocks, including those on GPS satellites. When Every Nanosecond Counts All atomic clocks have some degree of instability that leads to an offset in the clock’s time versus the actual time. If not corrected, the offset, while miniscule, increases rapidly, and with spacecraft navigation, even a tiny offset could have drastic effects. One of the key goals of the Deep Space Atomic Clock mission was to measure the clock’s stability over longer and longer periods, to see how it changes with time. In the new paper, the team reports a level of stability that leads to a time deviation of less than four nanoseconds after more than 20 days of operation. “As a general rule, an uncertainty of one nanosecond in time corresponds to a distance uncertainty of about one foot,” said Eric Burt, an atomic clock physicist for the mission at JPL and co-author of the new paper. “Some GPS clocks must be updated several times a day to maintain this level of stability, and that means GPS is highly dependent on communication with the ground. The Deep Space Atomic Clock pushes this out to a week or more, thus potentially giving an application like GPS much more autonomy.” The stability and subsequent time delay reported in the new paper is about five times better than what the team reported in the spring of 2020. This does not represent an improvement in the clock itself, but in the team’s measurement of the clock’s stability. Longer operating periods and almost a full year of additional data made it possible to improve the precision of their measurement. The Deep Space Atomic Clock mission will conclude in August, but NASA announced that work on this technology continues: the Deep Space Atomic Clock-2, an improved version of the cutting-edge timekeeper, will fly on the VERITAS (short for Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) mission to Venus. Like its predecessor, the new space clock is a technology demonstration, meaning its goal is to advance in-space capabilities by developing instruments, hardware, software, or the like that doesn't currently exist. Built by JPL and funded by NASA’s Space Technology Mission Directorate (STMD), the ultra-precise clock signal generated with this technology could help enable autonomous spacecraft navigation and enhance radio science observations on future missions. “NASA’s selection of Deep Space Atomic Clock-2 on VERITAS speaks to this technology’s promise,” said Todd Ely, Deep Space Atomic Clock principal investigator and project manager at JPL. “On VERITAS, we aim to put this next generation space clock through its paces and demonstrate its potential for deep space navigation and science.” More About the Mission The Deep Space Atomic Clock is hosted on a spacecraft provided by General Atomics Electromagnetic Systems of Englewood, Colorado. It is sponsored by STMD’s Technology Demonstration Missions program located at NASA’s Marshall Space Flight Center in Huntsville, Alabama, and NASA’s Space Communications and Navigation (SCaN) program within NASA’s Human Exploration and Operations Mission Directorate. JPL manages the project.