“When it comes to wheeled vehicles on other planets, there are few first-time events that measure up in significance to that of the first drive,” said Anais Zarifian, Mars 2020 Perseverance rover mobility test bed engineer at NASA’s Jet Propulsion Laboratory in Southern California. “This was our first chance to ‘kick the tires’ and take Perseverance out for a spin. The rover’s six-wheel drive responded superbly. We are now confident our drive system is good to go, capable of taking us wherever the science leads us over the next two years.”

The drive, which lasted about 33 minutes, propelled the rover forward 13 feet (4 meters), where it then turned in place 150 degrees to the left and backed up 8 feet (2.5 meters) into its new temporary parking space. To help better understand the dynamics of a retrorocket landing on the Red Planet, engineers used Perseverance’s Navigation and Hazard Avoidance Cameras to image the spot where Perseverance touched down, dispersing Martian dust with plumes from its engines.

More Than Roving

The rover’s mobility system is not only thing getting a test drive during this period of initial checkouts. On Feb. 26 — Perseverance’s eighth Martian day, or sol, since landing — mission controllers completed a software update, replacing the computer program that helped land Perseverance with one they will rely on to investigate the planet.

More recently, the controllers checked out Perseverance’s Radar Imager for Mars’ Subsurface Experiment (RIMFAX) and Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instruments, and deployed the Mars Environmental Dynamics Analyzer (MEDA) instrument’s two wind sensors, which extend out from the rover’s mast. Another significant milestone occurred on March 2, or Sol 12, when engineers unstowed the rover’s 7-foot-long (2-meter-long) robotic arm for the first time, flexing each of its five joints over the course of two hours.

“Tuesday’s first test of the robotic arm was a big moment for us,” said Robert Hogg, Mars 2020 Perseverance rover deputy mission manager. “That’s the main tool the science team will use to do close-up examination of the geologic features of Jezero Crater, and then we’ll drill and sample the ones they find the most interesting. When we got confirmation of the robotic arm flexing its muscles, including images of it working beautifully after its long trip to Mars — well, it made my day.”

Upcoming events and evaluations include more detailed testing and calibration of science instruments, sending the rover on longer drives, and jettisoning covers that shield both the adaptive caching assembly (part of the rover’s Sample Caching System) and the Ingenuity Mars Helicopter during landing. The experimental flight test program for the Ingenuity Mars Helicopter will also take place during the rover’s commissioning.

Through it all, the rover is sending down images from the most advanced suite of cameras ever to travel to Mars. The mission’s cameras have already sent about 7,000 images. On Earth, Perseverance’s imagery flows through the powerful Deep Space Network (DSN), managed by NASA’s Space Communications and Navigation (SCaN) program. In space, several Mars orbiters play an equally important role.

“Orbiter support for downlink of data has been a real gamechanger,” said Justin Maki, chief engineer for imaging and the imaging scientist for the Mars 2020 Perseverance rover mission at JPL. “When you see a beautiful image from Jezero, consider that it took a whole team of Martians to get it to you. Every picture from Perseverance is relayed by either the European Space Agency’s Trace Gas Orbiter, or NASA’s MAVEN, Mars Odyssey, or Mars Reconnaissance Orbiter. They are important partners in our explorations and our discoveries.”

The sheer volume of imagery and data already coming down on this mission has been a welcome bounty for Matt Wallace, who recalls waiting anxiously for the first images to trickle in during NASA’s first Mars rover mission, Sojourner, which explored Mars in 1997. On March 3, Wallace became the mission’s new project manager. He replaced John McNamee, who is stepping down as he intended, after helming the project for nearly a decade.

“John has provided unwavering support to me and every member of the project for over a decade,” said Wallace. “He has left his mark on this mission and team, and it has been my privilege to not only call him boss but also my friend.”

Touchdown Site Named

With Perseverance departing from its touchdown site, mission team scientists have memorialized the spot, informally naming it for the late science fiction author Octavia E. Butler. The groundbreaking author and Pasadena, California, native was the first African American woman to win both the Hugo Award and Nebula Award, and she was the first science fiction writer honored with a MacArthur Fellowship. The location where Perseverance began its mission on Mars now bears the name “Octavia E. Butler Landing.”

Official scientific names for places and objects throughout the solar system — including asteroids, comets, and locations on planets — are designated by the International Astronomical Union. Scientists working with NASA’s Mars rovers have traditionally given unofficial nicknames to various geological features, which they can use as references in scientific papers.

“Butler’s protagonists embody determination and inventiveness, making her a perfect fit for the Perseverance rover mission and its theme of overcoming challenges,” said Kathryn Stack Morgan, deputy project scientist for Perseverance. “Butler inspired and influenced the planetary science community and many beyond, including those typically under-represented in STEM fields.”

“I can think of no better person to mark this historic landing site than Octavia E. Butler, who not only grew up next door to JPL in Pasadena, but she also inspired millions with her visions of a science-based future,” said Thomas Zurbuchen, NASA Associate Administrator for science. “Her guiding principle, ‘When using science, do so accurately,’ is what the science team at NASA is all about. Her work continues to inspire today’s scientists and engineers across the globe — all in the name of a bolder, more equitable future for all.”

Butler, who died in 2006, authored such notable works as “Kindred,” “Bloodchild,” “Speech Sounds,” “Parable of the Sower,” “Parable of the Talents,” and the “Patternist” series. Her writing explores themes of race, gender, equality, and humanity, and her works are as relevant today as they were when originally written and published.

More About the Mission

A key objective of 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.

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, built and manages operations of the Perseverance rover.

For more about Perseverance:

https://www.nasa.gov/perseverance

and

https://mars.nasa.gov/mars2020

For more information about NASA’s Mars missions, go to:

https://www.nasa.gov/mars

The group of investigators published their findings March 5 in Cell Stem Cell. This is the first time scientists have reported modifying a NG2 glia — a type of supporting cell in the central nervous system — into functional neurons after spinal cord injury, said Wei Wu, PhD, research associate in neurological surgery at IU School of Medicine and co-first author of the paper.

Wu and Xiao-Ming Xu, PhD, the Mari Hulman George Professor of Neuroscience Research at IU School of Medicine, worked on the study with a team of scientists from the University of Texas Southwestern Medical Center. Xu is also a primary member of Stark Neurosciences Research Institute, where he leads the Indiana Spinal Cord and Brain Injury Research Group.

Spinal cord injuries affect hundreds of thousands of people in the United States, with thousands more diagnosed each year. Neurons in the spinal cord don’t regenerate after injury, which typically causes a person to experience permanent physical and neurological ailments.

“Unfortunately, effective treatments for significant recovery remain to be developed,” Xu said. “We hope that this new discovery will be translated to a clinically relevant repair strategy that benefits those who suffer from a spinal cord injury.”

When the spinal cord is injured, glial cells, of which there are three types — astrocyte, ependymal and NG2 — respond to form glial scar tissue.

“Only NG2 glial cells were found to exhibit neurogenic potential in the spinal cord following injury in adult mice, but they failed to generate mature neurons,” Wu said. “Interestingly, by elevating the critical transcription factor SOX2, the glia-to-neuron conversion is successfully achieved and accompanied with a reduced glial scar formation and increased functional recovery following spinal cord injury.”

The researchers reprogrammed the NG2 cells from the mouse model using elevated levels of SOX2 — a transcription factor found inside the cell that’s essential for neurogenesis — to neurons. This conversion has two purposes, Xu said: generate neurons to replace those lost due to a spinal cord injury and reduce the size of the glial scars in the lesion area of the damaged tissue.

This discovery, Wu said, serves as an important target in the future for potential therapeutic treatments of spinal cord injury.

The partnership between the laboratory of Chun-Li Zhang, PhD, professor at UT Southwestern Medical Center, and Xu’s laboratory at IU School of Medicine greatly benefited the research, Xu added, by offering complementary expertise in neuronal reprogramming and in spinal cord injury, respectively.

“Such a collaboration will be continued between the two laboratories to address neuronal remodeling and functional recovery after successful conversion of glial cells into functional neurons in future,” Xu said.

Story Source:

Materials provided by Indiana University School of Medicine. Note: Content may be edited for style and length.

The new testing method revealed large quantities of previously undetected PFAS from fire-retardant foams and other unknown sources. Total concentrations of PFAS present in these watersheds were above state maximum contaminant levels (MCLs) for drinking water safety.

“We developed a method to fully capture and characterize all PFAS from fire-retardant foams, which are a major source of PFAS to downstream drinking water and ecosystems, but we also found large amounts of unidentified PFAS that couldn’t have originated from these foams,” said Bridger Ruyle, a graduate student at SEAS and first author of the study. “Traditional testing methods are completely missing these unknown PFAS.”

The research will be published in Environmental Science & Technology.

PFAS — per- and polyfluoroalkyl substances — are present in products ranging from fire retardant foams to non-stick pans. Nicknamed “forever chemicals” due to their long lifespan, PFAS have been building up in the environment since they were first used in the 1950s.

Despite the associated health risks, there are no legally enforceable federal limits for PFAS chemicals in drinking water. The Environmental Protection Agency’s provisional health guidelines for public water supplies only cover PFOS and PFOA, two common types of PFAS. Massachusetts, along with a few other states, has gone further by including six PFAS in their new MCLs in drinking water. But there are thousands of PFAS chemical structures known to exist, several hundred of which have already been detected in the environment.

“We’re simply not testing for most PFAS compounds, so we have no idea what our total exposure is to these chemicals and health data associated with such exposures are still lacking,” said Elsie Sunderland, the Gordon McKay Professor of Environmental Chemistry at SEAS and senior author of the paper.

The standard testing methods used by the EPA and state regulatory agencies only test for 25 or fewer known compounds. The problem is the overwhelming majority of PFAS compounds are proprietary and regulatory agencies can’t find what they don’t know exist.

The new method developed by Sunderland and her team can overcome that barrier and account for all PFAS in a sample. CSI: PFAS

PFAS are made by combining carbons and fluorine atoms to form one of the strongest bonds in organic chemistry. Fluorine is one of the most abundant elements on earth but naturally occurring organic fluorine is exceedingly rare — produced only by a few poisonous plants in the Amazon and Australia. Therefore, any amount of organofluorine detected in the environment is sure to be human made.

PFAS compounds found in the environment come in two forms: a precursor form and a terminal form. Most of the monitored PFAS compounds, including PFOS and PFOA, are terminal compounds, meaning they will not degrade under normal environmental conditions. But precursor compounds, which often make up the majority of PFAS chemicals in a sample, can be transformed through biological or environmental processes into terminal forms. So, while the EPA or state agencies may monitor PFAS concentrations, they still are not detecting much of the huge pool of PFAS precursors.

That’s where this new method comes in.

The researchers first measure all the organofluorine in a sample. Then, using another technique, they oxidize the precursors in that sample and transform them into their terminal forms, which they can then measure. From there, the team developed a method of statistical analysis to reconstruct the original precursors, fingerprint their manufacturing origin, and measure their concentration within the sample.

“We’re essentially doing chemical forensics,” said Sunderland.

Using this method, Sunderland and her team tested six watersheds on Cape Cod as part of a collaboration with the United States Geological Survey and a research center funded by the National Institutes of Health and led by the University of Rhode Island that focuses on the sources, transport, exposure and effects of PFAS.

The team focused on identifying PFAS from the use of fire-retardant foams. These foams, which are used extensively at military bases, civilian airports, and local fire departments, are a major source of PFAS and have contaminated hundreds of public water supplies across the US.

The research team applied their forensic methods to samples collected between August 2017 and July 2019 from the Childs, Quashnet, Mill Creek, Marstons Mills, Mashpee and Santuit watersheds on Cape Cod. During the collection process, the team members had to be careful what they wore, since waterproof gear is treated with PFAS. The team ended up in decades-old waders to prevent contamination.

The sampling sites in the Childs, Quashnet and Mill Creek watersheds are downstream from a source of PFAS from fire retardant foams — the Quashnet and Childs from The Joint Base Cape Cod military facility and Mill Creek from Barnstable County Fire Training Academy.

Current tests can only identify about 50 percent of PFAS from historical foams — products that were discontinued in 2001 due to high levels of PFOS and PFOA — and less than 1 percent of PFAS from modern foams.

Using their new method, Sunderland and her team were able to identify 100 percent of all PFAS compounds in the types of fire-retardant foams that were used for decades at Joint Base Cape Cod and Barnstable County Fire Training Academy.

“Our testing method was able to find these missing compounds that have been used by the chemical industry for more than 40 years,” said Sunderland.

The tests also revealed huge quantities of PFAS from unknown sources.

“Our accounting of PFAS from firefighting foams could not explain 37 to 77 percent of the organofluorine that we measured,” said Ruyle. “This has huge ramifications for not only our understanding of human exposure but also for how much PFAS is discharging into the ocean and accumulating in marine life.”

To follow up on these findings, Ruyle is currently working with NIH to identify some of the health impacts of PFAS from contemporary firefighting foams using toxicology studies. Sunderland’s team is continuing to study the unknown PFAS to better identify their sources and potential for accumulation in abundant marine food webs on Cape Cod.