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Webb Webb News Latest News Latest Images Blog (offsite) Awards X (offsite – login reqd) Instagram (offsite – login reqd) Facebook (offsite- login reqd) Youtube (offsite) Overview About Who is James Webb? Fact Sheet Impacts+Benefits FAQ Science Overview and Goals Early Universe Galaxies Over Time Star Lifecycle Other Worlds Observatory Overview Launch Orbit Mirrors Sunshield Instrument: NIRCam Instrument: MIRI Instrument: NIRSpec Instrument: FGS/NIRISS Optical Telescope Element Backplane Spacecraft Bus Instrument Module Multimedia About Webb Images Images Videos What is Webb Observing? 3d Webb in 3d Solar System Podcasts Webb Image Sonifications Team International Team People Of Webb More For the Media For Scientists For Educators For Fun/Learning 6 Min Read Webb Watches Carbon-Rich Dust Shells Form, Expand in Star System
A portion of Webb’s 2023 observation of Wolf-Rayet 140. Credits:
Image: NASA, ESA, CSA, STScI; Science: Emma Lieb (University of Denver), Ryan Lau (NSF NOIRLab), Jennifer Hoffman (University of Denver) Astronomers have long tried to track down how elements like carbon, which is essential for life, become widely distributed across the universe. Now, NASA’s James Webb Space Telescope has examined one ongoing source of carbon-rich dust in our own Milky Way galaxy in greater detail: Wolf-Rayet 140, a system of two massive stars that follow a tight, elongated orbit.
As they swing past one another (within the central white dot in the Webb images), the stellar winds from each star slam together, the material compresses, and carbon-rich dust forms. Webb’s latest observations show 17 dust shells shining in mid-infrared light that are expanding at regular intervals into the surrounding space.
Image A: Compare Observations of Wolf-Rayet 140 (MIRI Images)
Two mid-infrared images from NASA’s James Webb Space Telescope of Wolf-Rayet 140 show carbon-rich dust moving in space. At right, the two triangles from the main images are matched up to show how much difference 14 months makes: The dust is racing away from the central stars at almost 1% the speed of light. These stars are 5,000 light-years away in our own Milky Way galaxy. Image: NASA, ESA, CSA, STScI; Science: Emma Lieb (University of Denver), Ryan Lau (NSF NOIRLab), Jennifer Hoffman (University of Denver) “The telescope not only confirmed that these dust shells are real, its data also showed that the dust shells are moving outward at consistent velocities, revealing visible changes over incredibly short periods of time,” said Emma Lieb, the lead author of the new paper and a doctoral student at the University of Denver in Colorado.
Every shell is racing away from the stars at more than 1,600 miles per second (2,600 kilometers per second), almost 1% the speed of light. “We are used to thinking about events in space taking place slowly, over millions or billions of years,” added Jennifer Hoffman, a co-author and a professor at the University of Denver. “In this system, the observatory is showing that the dust shells are expanding from one year to the next.”
Like clockwork, the stars’ winds generate dust for several months every eight years, as the pair make their closest approach during a wide, elongated orbit. Webb also shows how dust formation varies — look for the darker region at top left in both images.
Video A: Fade Between 2022 and 2023 Observations of Wolf-Rayet 140
This video alternates between two mid-infrared light observations from NASA’s James Webb Space Telescope of Wolf-Rayet 140. Over only 14 months, Webb showed the dust in the system has expanded. This two-star system has sent out more than 17 shells of dust over 130 years. Video: NASA, ESA, CSA, STScI.; Science: Emma Lieb (University of Denver), Ryan Lau (NSF NOIRLab), Jennifer Hoffman (University of Denver) Video B: Stars’ Orbits in Wolf-Rayet 140 (Visualization)
When the two massive stars in Wolf-Rayet 140 swing past one another, their winds collide, material compresses, and carbon-rich dust forms. The stronger winds of the hotter star in the Wolf-Rayet system blow behind its slightly cooler (but still hot) companion. The stars create dust for several months in every eight-year orbit.
Video: NASA, ESA, CSA, Joseph Olmsted (STScI). The telescope’s mid-infrared images detected shells that have persisted for more than 130 years. (Older shells have dissipated enough that they are now too dim to detect.) The researchers speculate that the stars will ultimately generate tens of thousands of dust shells over hundreds of thousands of years.
“Mid-infrared observations are absolutely crucial for this analysis, since the dust in this system is fairly cool. Near-infrared and visible light would only show the shells that are closest to the star,” explained Ryan Lau, a co-author and astronomer at NSF NOIRLab in Tuscon, Arizona, who led the initial research about this system. “With these incredible new details, the telescope is also allowing us to study exactly when the stars are forming dust — almost to the day.”
The dust’s distribution isn’t uniform. Though this isn’t obvious at first glance, zooming in on the shells in Webb’s images reveals that some of the dust has “piled up,” forming amorphous, delicate clouds that are as large as our entire solar system. Many other individual dust particles float freely. Every speck is as small as one-hundredth the width of a human hair. Clumpy or not, all of the dust moves at the same speed and is carbon rich.
The Future of This System
What will happen to these stars over millions or billions of years, after they are finished “spraying” their surroundings with dust? The Wolf-Rayet star in this system is 10 times more massive than the Sun and nearing the end of its life. In its final “act,” this star will either explode as a supernova — possibly blasting away some or all of the dust shells — or collapse into a black hole, which would leave the dust shells intact.
Though no one can predict with any certainty what will happen, researchers are rooting for the black hole scenario. “A major question in astronomy is, where does all the dust in the universe come from?” Lau said. “If carbon-rich dust like this survives, it could help us begin to answer that question.”
“We know carbon is necessary for the formation of rocky planets and solar systems like ours,” Hoffman added. “It’s exciting to get a glimpse into how binary star systems not only create carbon-rich dust, but also propel it into our galactic neighborhood.”
These results have been published in the Astrophysical Journal Letters and were presented in a press conference at the 245th meeting of the American Astronomical Society in National Harbor, Maryland.
The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
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Laura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Claire Blome – cblome@stsci.edu, Christine Pulliam – cpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Science – Emma Lieb (University of Denver)
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Last Updated Jan 13, 2025 Editor Marty McCoy Contact Laura Betz laura.e.betz@nasa.gov Related Terms
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Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles, or MARVL, aims to take a critical element of nuclear electric propulsion, its heat dissipation system, and divide it into smaller components that can be assembled robotically and autonomously in space. This is an artist’s rendering of what the fully assembled system might look like.NASA The trip to Mars and back is not one for the faint of heart. We’re not talking days, weeks, or months. But there are technologies that could help transport a crew on that round-trip journey in a relatively quick two years.
One option NASA is exploring is nuclear electric propulsion, which employs a nuclear reactor to generate electricity that ionizes, or positively charges, and electrically accelerates gaseous propellants to provide thrust to a spacecraft.
Researchers at NASA’s Langley Research Center in Hampton, Virginia, are working on a system that could help bring nuclear electric propulsion one significant, technology-defining step closer to reality.
Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles, or MARVL, aims to take a critical element of nuclear electric propulsion, its heat dissipation system, and divide it into smaller components that can be assembled robotically and autonomously in space.
“By doing that, we eliminate trying to fit the whole system into one rocket fairing,” said Amanda Stark, a heat transfer engineer at NASA Langley and the principal investigator for MARVL. “In turn, that allows us to loosen up the design a little bit and really optimize it.”
Loosening up the design is key, because as Stark mentioned, previous ideas called for fitting the entire nuclear electric radiator system under a rocket fairing, or nose cone, which covers and protects a payload. Fully deployed, the heat dissipating radiator array would be roughly the size of a football field. You can imagine the challenge engineers would face in getting such a massive system folded up neatly inside the tip of a rocket.
The MARVL technology opens a world of possibilities. Rather than cram the whole system into an existing rocket, this would allow researchers the flexibility to send pieces of the system to space in whatever way would make the most sense, then have it all assembled off the planet.
Once in space, robots would connect the nuclear electric propulsion system’s radiator panels, through which a liquid metal coolant, such as a sodium-potassium alloy, would flow.
While this is still an engineering challenge, it is exactly the kind of engineering challenge in-space-assembly experts at NASA Langley have been working on for decades. The MARVL technology could mark a significant first milestone. Rather than being an add-on to an existing technology, the in-space assembly component will benefit and influence the design of the very spacecraft it would serve.
“Existing vehicles have not previously considered in-space assembly during the design process, so we have the opportunity here to say, ‘We’re going to build this vehicle in space. How do we do it? And what does the vehicle look like if we do that?’ I think it’s going to expand what we think of when it comes to nuclear propulsion,” said Julia Cline, a mentor for the project in NASA Langley’s Research Directorate, who led the center’s participation in the Nuclear Electric Propulsion tech maturation plan development as a precursor to MARVL. That tech maturation plan was run out of the agency’s Space Nuclear Propulsion project at Marshall Space Flight Center in Huntsville, Alabama.
NASA’s Space Technology Mission Directorate awarded the MARVL project through the Early Career Initiative, giving the team two years to advance the concept. Stark and her teammates are working with an external partner, Boyd Lancaster, Inc., to develop the thermal management system. The team also includes radiator design engineers from NASA’s Glenn Research Center in Cleveland and fluid engineers from NASA’s Kennedy Space Center in Florida. After two years, the team hopes to move the MARVL design to a small-scale ground demonstration.
The idea of robotically building a nuclear propulsion system in space is sparking imaginations.
“One of our mentors remarked, ‘This is why I wanted to work at NASA, for projects like this,’” said Stark, “which is awesome because I am so happy to be involved with it, and I feel the same way.”
Additional support for MARVL comes from the agency’s Space Nuclear Propulsion project. The project’s ongoing effort is maturing technologies for operations around the Moon and near-Earth exploration, deep space science missions, and human exploration using nuclear electric propulsion and nuclear thermal propulsion.
An artist’s rendering that shows the different components of a fully assembled nuclear electric propulsion system.NASAView the full article
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4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
Danah Tommalieh, commercial pilot and engineer at Reliable Robotics, inputs a flight plan at the control center in Mountain View, California, ahead of remotely operating a Cessna 208 aircraft at Hollister municipal airport in Hollister, California.NASA/Don Richey NASA recently began a series of flight tests with partners to answer an important aviation question: What will it take to integrate remotely piloted or autonomous planes carrying large packages and cargo safely into the U.S. airspace? Researchers tested new technologies in Hollister, California, that are helping to investigate what tools and capabilities are needed to make these kinds of flights routine.
The commercial industry continues to make advancements in autonomous aircraft systems aimed at making it possible for remotely operated aircraft to fly over communities – transforming the way we will transport people and goods. As the Federal Aviation Administration (FAA) develops standards for this new type of air transportation, NASA is working to ensure these uncrewed flights are safe by creating the required technological tools and infrastructure. These solutions could be scaled to support many different remotely piloted aircraft – including air taxis and package delivery drones – in a shared airspace with traditional crewed aircraft.
“Remotely piloted aircraft systems could eventually deliver cargo and people to rural areas with limited access to commercial transportation and delivery services,” said Shivanjli Sharma, aerospace engineer at NASA’s Ames Research Center in California’s Silicon Valley. “We’re aiming to create a healthy ecosystem of many different kinds of remotely piloted operations. They will fly in a shared airspace to provide communities with better access to goods and services, like medical supply deliveries and more efficient transportation.”
During a flight test in November, Reliable Robotics, a company developing an autonomous flight system, remotely flew its Cessna 208 Caravan aircraft through pre-approved flight paths in Hollister, California.
Although a safety pilot was aboard, a Reliable Robotics remote pilot directed the flight from their control center in Mountain View, more than 50 miles away.
Cockpit of Reliable Robotics’ Cessna 208 aircraft outfitted with autonomous technology for remotely-piloted operations.NASA/Brandon Torres Navarrete Congressional staffers from the United States House and Senate’s California delegation joined NASA Deputy Associate Administrator for Aeronautics Research Mission Directorate, Carol Caroll, Ames Aeronautics Director, Huy Tran, and other Ames leadership at Reliable Robotics Headquarters to view the live remote flight.
Researchers evaluated a Collins Aerospace ground-based surveillance system’s ability to detect nearby air traffic and provide the remote pilot with information in order to stay safely separated from other aircraft in the future.
Initial analysis shows the ground-based radar actively surveilled the airspace during the aircraft’s taxi, takeoff, and landing. The data was transmitted from the radar system to the remote pilot at Reliable Robotics. In the future, this capability could help ensure aircraft remain safely separated across all phases of fight.
A Reliable Robotics’ modified Cessna 208 aircraft flies near Hollister Airport. A Reliable Robotics pilot operated the aircraft remotely from the control center in Mountain View.NASA/Brandon Torres Naverrete While current FAA operating rules require pilots to physically see and avoid other aircraft from inside the cockpit, routine remotely piloted aircraft will require a suite of integrated technologies to avoid hazards and coordinate with other aircraft in the airspace.
A radar system for ground-based surveillance offers one method for detecting other traffic in the airspace and at the airport, providing one part of the capability to ensure pilots can avoid collision and accomplish their desired missions. Data analysis from this testing will help researchers understand if ground-based surveillance radar can be used to satisfy FAA safety rules for remotely piloted flights.
NASA will provide analysis and reports of this flight test to the FAA and standards bodies.
“This is an exciting time for the remotely piloted aviation community,” Sharma said. “Among other benefits, remote operations could provide better access to healthcare, bolster natural disaster response efforts, and offer more sustainable and effective transportation to both rural and urban communities. We’re thrilled to provide valuable data to the industry and the FAA to help make remote operations a reality in the near future.”
Over the next year, NASA will work with additional aviation partners on test flights and simulations to test weather services, communications systems, and other autonomous capabilities for remotely piloted flights. NASA researchers will analyze data from these tests to provide a comprehensive report to the FAA and the community on what minimum technologies and capabilities are needed to enable and scale remotely piloted operations.
This flight test data analysis is led out of NASA Ames under the agency’s Air Traffic Management Exploration project. This effort supports the agency’s Advanced Air Mobility mission research, ensuring the United States stays at the forefront of aviation innovation.
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Last Updated Jan 07, 2025 Related Terms
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6 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
In-person participants L-R standing: Dave Francisco, Joanne Kaouk, Dr. Richard Moon, Dr. Tony Alleman, Dr. Sean Hardy, Sarah Childress, Kristin Coffey, Dr. Ed Powers, Dr. Doug Ebersole, Dr. Steven Laurie, Dr. Doug Ebert; L-R seated: Dr. Alejandro Garbino, Dr. Robert Sanders, Dr. Kristi Ray, Dr. Mike Gernhardt, Dr. Joseph Dervay, Dr. Matt Makowski). Not pictured: Dr. Caroline Fife In June 2024, the NASA Office of the Chief Health and Medical Officer (OCHMO) Standards Team hosted an independent assessment working group to review the status and progress of research and clinical activities intended to mitigate the risk of decompression sickness (DCS) related to patent foramen ovale (PFO) during spaceflight and associated ground testing and human subject studies.
Decompression sickness (DCS) is a condition which results from dissolved gases (primarily nitrogen) forming bubbles in the bloodstream and tissues. It is usually experienced in conditions where there are rapid decreases in ambient pressure, such as in scuba divers, high-altitude aviation, or other pressurized environments. The evolved gas bubbles have various physiological effects and can obstruct the blood vessels, trigger inflammation, and damage tissue, resulting in symptoms of DCS. NASA presently classifies DCS into two categories: Type I DCS, which is less severe, typically leads to musculoskeletal symptoms including pain in the joints or muscles, or skin rash. Type II DCS is more severe and commonly results in neurological, inner ear, and cardiopulmonary symptoms. The risk of DCS in spaceflight presents during extravehicular activities (EVAs) in which astronauts perform mission tasks outside the spaceflight vehicle while wearing a pressurized suit at a lower pressure than the cabin pressure. DCS mitigation protocols based on strategies to reduce systemic nitrogen load are implemented through the combination of habitat environmental parameters, EVA suit pressure, and breathing gas procedures (prebreathe protocols) to achieve safe and effective mission operations. The pathophysiology of DCS has still not been fully elucidated since cases occur despite the absence of detected gas bubbles but includes right to left shunting of venous gas emboli (VGE) via several potential mechanisms, one of which is a Patent Foramen Ovale (PFO).
From: Dr. Schochet & Dr. Lie, Pediatric Pulmonologists
Reference OCHMO-TB-037 Decompression Sickness (DCS) Risk Mitigation technical brief for additional information.
A PFO is a shunt between the right atrium and the left atrium of the heart, which is a persisting remnant of a physiological communication present in the fetal heart. Post-natal increases in left atrial pressure usually force the inter-septal valve against the septum secundum and within the first 2 years of life, the septae permanently fuse due to the development of fibrous adhesions. Thus, all humans are born with a PFO and approximately 75% of PFOs fuse following childbirth. For the 25% of the population’s whose PFOs do not fuse, ~6% have what is considered by some to be a large PFO (> 2 mm). PFO diameter can increase with age. The concern with PFOs is that with a right to left shunt between the atria, venous emboli gas may pass from the right atrium (venous) to the left atrium (arterial) (“shunt”), thus by-passing the normal lung filtration of venous emboli which prevent passage to the arterial system. Without filtration, bubbles in the arterial system may lead to a neurological event such as a stroke. Any activity that increases the right atrium/venous pressure over the left atrium/arterial pressure (such as a Valsalva maneuver, abdominal compression) may further enable blood and/or emboli across a PFO/shunt.
From: Nuffield Department of Clinical Neurosciences
The purpose of this working group was to review and provide analysis on the status and progress of research and clinical activities intended to mitigate the risk of PFO and DCS issues during spaceflight. Identified cases of DCS during NASA exploration atmosphere ground testing conducted in pressurized chambers led to the prioritization of the given topic for external review. The main goals of the working group included:
Quantification of any increased risk associated with the presence of a PFO during decompression protocols utilized in ground testing and spaceflight EVAs, as well as unplanned decompressions (e.g., cabin depressurization, EVA suit leak). Describe risks and benefits of PFO screening in astronaut candidates, current crewmembers, and chamber test subjects. What are potential risk reduction measures that could be considered if a person was believed to be at increased risk of DCS due to a PFO? What research and/or technology development is recommended that could help inform and/or mitigate PFO-related DCS risk? The working group took place over two days at NASA’s Johnson Space Center and included NASA subject matter experts and stakeholders, as well as invited external reviewers from areas including cardiology, hypobaric medicine, spaceflight medicine, and military occupational health. During the working group, participants were asked to review past reports and evidence related to PFOs and risk of DCS, materials and information regarding NASA’s current experience and practices, and case studies and subsequent decision-making processes. The working group culminated in an open-forum discussion where recommendations for current and future practices were conferred and subsequently summarized in a final summary report, available on the public NASA OCHMO Standards Team website.
The following key findings are the main take-aways from the OCHMO independent assessment:
In an extreme exposure/high-risk scenario, excluding individuals with a PFO and treating PFOs does not necessarily decrease the risk of DCS or create a ‘safe’ environment. It may create incremental differences and slightly reduce overall risk but does not make the risk zero. There are other physiological factors that also contribute to the risk of DCS that may have a larger impact (see 7.0 Other Physiological Factors in the findings section). Based on the available evidence and the risk of current decompression exposures (based on current NASA protocols and NASA-STD-3001 requirements to limit the risk of DCS), it is not recommended to screen for PFOs in any spaceflight or ground testing participants. The best strategy to reduce the risk of DCS is to create as safe an environment as possible in every scenario, through effective prebreathe protocols, safety, and the capability to rapidly treat DCS should symptoms occur. Based on opinion, no specific research is required at this time to further characterize PFOs with DCS and altitude exposure, due to the low risk and preference to institute adequate safe protocols and ensuring treatment availability both on the ground and in spaceflight. For engineering protocols conducted on the ground, it should be ensured that the same level of treatment capability (treatment chamber in the immediate vicinity of the testing) is provided as during research protocols. The ability to immediately treat a DCS case is critical in ensuring the safety of the test subjects. The full summary report includes detailed background information, discussion points from the working group, and conclusions and recommendations. The findings from the working group and resulting summary report will help to inform key stakeholders in decision-making processes for future ground testing and spaceflight operations with the main goal of protecting crew health and safety to ensure overall mission success.
Summary Report About the Author
Sarah D. Childress
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Last Updated Dec 31, 2024 Related Terms
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Download PDF: Statistical Analysis Using Random Forest Algorithm Provides Key Insights into Parachute Energy Modulator System
Energy modulators (EM), also known as energy absorbers, are safety-critical components that are used to control shocks and impulses in a load path. EMs are textile devices typically manufactured out of nylon, Kevlar® and other materials, and control loads by breaking rows of stitches that bind a strong base webbing together as shown in Figure 1. A familiar EM application is a fall-protection harness used by workers to prevent injury from shock loads when the harness arrests a fall. EMs are also widely used in parachute systems to control shock loads experienced during the various stages of parachute system deployment.
Random forest is an innovative algorithm for data classification used in statistics and machine learning. It is an easy to use and highly flexible ensemble learning method. The random forest algorithm is capable of modeling both categorical and continuous data and can handle large datasets, making it applicable in many situations. It also makes it easy to evaluate the relative importance of variables and maintains accuracy even when a dataset has missing values.
Random forests model the relationship between a response variable and a set of predictor or independent variables by creating a collection of decision trees. Each decision tree is built from a random sample of the data. The individual trees are then combined through methods such as averaging or voting to determine the final prediction (Figure 2). A decision tree is a non-parametric supervised learning algorithm that partitions the data using a series of branching binary decisions. Decision trees inherently identify key features of the data and provide a ranking of the contribution of each feature based on when it becomes relevant. This capability can be used to determine the relative importance of the input variables (Figure 3). Decision trees are useful for exploring relationships but can have poor accuracy unless they are combined into random forests or other tree-based models.
The performance of a random forest can be evaluated using out-of-bag error and cross-validation techniques. Random forests often use random sampling with replacement from the original dataset to create each decision tree. This is also known as bootstrap sampling and forms a bootstrap forest. The data included in the bootstrap sample are referred to as in-the-bag, while the data not selected are out-of-bag. Since the out-of-bag data were not used to generate the decision tree, they can be used as an internal measure of the accuracy of the model. Cross-validation can be used to assess how well the results of a random forest model will generalize to an independent dataset. In this approach, the data are split into a training dataset used to generate the decision trees and build the model and a validation dataset used to evaluate the model’s performance. Evaluating the model on the independent validation dataset provides an estimate of how accurately the model will perform in practice and helps avoid problems such as overfitting or sampling bias. A good model performs well on
both the training data and the validation data.
The complex nature of the EM system made it difficult for the team to identify how various parameters influenced EM behavior. A bootstrap forest analysis was applied to the test dataset and was able to identify five key variables associated with higher probability of damage and/or anomalous behavior. The identified key variables provided a basis for further testing and redesign of the EM system. These results also provided essential insight to the investigation and aided in development of flight rationale for future use cases.
For information, contact Dr. Sara R. Wilson. sara.r.wilson@nasa.gov
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