Jump to content

NASA Tunnel Generates Decades of Icy Aircraft Safety Data


Recommended Posts

  • Publishers
Posted

5 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

A black-and-white photo of a man who stands inside the Icing Research Tunnel beside spray bars and the nose of a plane that is covered in ice. He is wearing a large fur-lined coat and holds a tall measurement stick and a sign that says, “Test No 1, Run No 1, Date 9-13-44” and provides other test information.
A National Advisory Committee for Aeronautics researcher notes the conditions on the P-39L after its first test run in the Icing Research Tunnel on Sept. 13, 1944. The aircraft was too large to fit in the test section, so it was installed downstream in a larger area of the tunnel. The initial tests analyzed ice buildup on the nose, propeller blades, and antennae. In the summer of 1945, the P-39L was used to demonstrate the effectiveness of a thermal pneumatic boot ice-prevention system and heated propeller blades.
Credit: NASA

On Sept. 13, 1944, researchers subjected a Bell P-39L Airacobra to frigid temperatures and a freezing water spray in the National Advisory Committee for Aeronautics (NACA)’s new Icing Research Tunnel (IRT) to study inflight ice buildup. Since that first run at the Aircraft Engine Research Laboratory (now NASA’s Glenn Research Center) in Cleveland, the facility has operated on a regular basis for 80 years and remains the oldest and one of the largest icing tunnels in the world.

Water droplets in clouds can freeze on aircraft surfaces in certain atmospheric conditions. Ice buildup on the forward edges of wings and tails causes significant decreases in lift and rapid increases in drag. Ice can also block engine intakes and add weight. NASA has a long tradition of working to understand the conditions that cause icing and developing systems that prevent and remove ice buildup.

The NACA decided to build its new icing tunnel adjacent to the lab’s Altitude Wind Tunnel to take advantage of its powerful cooling equipment and unprecedented refrigeration system. The system, which can reduce air temperature to around –30 degrees Fahrenheit, produces realistic and repeatable icing conditions using a spray nozzle system that creates small, very cold droplets and a drive fan that generates airspeeds up to 374 miles per hour.

A black-and-white photo of the inside of the Icing Research Tunnel. A man stands beneath the back end of a massive fan.
View upstream of the Icing Research Tunnel’s 25-foot-diameter drive fan in 1944. The original 12-bladed wooden fan and its 4,100-horsepower motor could produce air speeds up to 300 miles per hour. The motor and fan were replaced in 1987 and 1993, respectively.
Credit: NASA

Two rudimentary icing tunnels had briefly operated at the NACA’s Langley Memorial Aeronautical Laboratory in Hampton, Virginia, but icing research primarily relied on flight testing. The sophisticated new tunnel in Cleveland offered a safer way to study icing physics, test de-icing systems, and develop icing instrumentation.

During World War II, inlet icing was a key contributor to the heavy losses suffered by C-46s flying supply missions to allied troops in China. In February 1945, a large air scoop from the C-46 Commando was installed in the tunnel, where researchers determined the cause of the issue and redesigned the scoop to prevent freezing water droplets entering. The modifications were later incorporated into the C–46 and Convair C–40.

A black-and-white photo of the Icing Research Tunnel’s water spray system. Water sprays from equipment that includes multiple bars and tubes. A person crouches inside the tunnel in front of the stream of droplets.
A National Advisory Committee for Aeronautics engineer experiments with an Icing Research Tunnel water spray system design in September 1949. Researchers used data taken from research flights to determine the proper droplet sizes. The atomizing spray system was perfected in 1950.
Credit: NASA

Despite these early successes, NACA engineers struggled to improve the facility’s droplet spray system because of a lack of small nozzles able to produce sufficiently small droplets. After years of dogged trial and error, the breakthrough came in 1950 with an 80-nozzle system that produced the uniform microscopic droplets needed to properly simulate a natural icing cloud. 

Usage of the IRT increased in the 1950s, and the controlled conditions produced by the facility helped researchers define specific atmospheric conditions that produce icing. The Civil Aeronautics Authority (the precursor to the Federal Aviation Administration) used this data to establish regulations for all-weather aircraft. The facility also contributed to new icing protections for antennae and jet engines and the development of cyclical heating de-icing systems.

The success of the NACA’s icing program, along with the increased use of jet engines – which permitted cruising above the weather – reduced the need for additional icing research. In early 1957, just before the NACA transitioned to NASA, the center’s icing program was terminated. Nonetheless, the IRT remained active throughout the 1960s and 1970s supporting industry testing.

An aerial view of the Icing Research Tunnel. A cluster of building can be seen beside a large wind tunnel along with cars and road areas. A title at the top of the photo says, “Icing Research Tunnel.”
The Icing Research Tunnel is highlighted in this 1973 aerial photograph. The larger Altitude Wind Tunnel (AWT) is located behind it, and the Refrigeration Building that supported both tunnels is immediately to the left of the AWT.
Credit: NASA

By the mid-1970s, new icing issues were arising due to the increased use of helicopters, regional airliners, and general aviation aircraft. The center held an icing workshop in July 1978 where over 100 icing experts from across the world converged and lobbied for a reinstatement of NASA’s icing research program.

The agency agreed to provide funding to support a small team of researchers and increase operation of the icing facility. In 1982, a deadly icing-related airline crash spurred NASA to bring back a full-fledged icing research program.

Nearly all the tunnel’s major components were subsequently upgraded. Use of the IRT skyrocketed, and there was at least a one-year wait for new tests during this period. In 1988, the facility operated more hours than any year since 1950.

An up-close view of ice that covers propeller blades inside the Icing Research Tunnel.
This model was installed in the Icing Research Tunnel in 2023 as part of the Advanced Air Mobility Rotor Icing Evaluation Study, which sought to refine testing of rotating models in the tunnel, validate 3D computational models, and study propeller icing issues.
Credit: NASA

The facility was used in a complementary way with the Twin Otter aircraft and computer simulation to improve de-icing systems, predictive tools, and instrumentation. IRT testing also accelerated the all-weather certification of the OH-60 Black Hawk helicopter. In the 1990s, the icing program turned its attention to combatting super-cooled large droplets, which can cause ice buildup in areas not protected by leading edge de-icing systems, and tailplane icing, which can cause commuter aircraft to pitch forward.

The IRT was one of the busiest facilities at the center in the 2000s and continues to maintain a steady test schedule today, investigating icing on turbofan engines and propellers, refining testing of rotating models, validating 3D models, and much more. The IRT been used to develop nearly every modern ice protection system, provided key icing environment data to regulatory agencies, and validated leading ice prediction software. After 80 years, it remains a critical tool for sustaining NASA’s leadership in the icing field.

More Resources:

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      The Axiom Mission 4 and Expedition 73 crews join together for a group portrait inside the International Space Station’s Harmony module. In the front row (from left) are Ax-4 crewmates Tibor Kapu, Peggy Whitson, Shubhanshu Shukla, and Sławosz Uznański-Wiśniewski with Expedition 73 crewmates Anne McClain and Takuya Onishi. In the rear are, Expedition 73 crewmates Alexey Zubritskiy, Kirill Peskov, Sergey Ryzhikov, Jonny Kim, and Nichole Ayers.Credit: NASA NASA will provide live coverage of the undocking and departure of the Axiom Mission 4 private astronaut mission from the International Space Station.
      The four-member astronaut crew is scheduled to undock from the space-facing port of the station’s Harmony module aboard the SpaceX Dragon spacecraft at approximately 7:05 a.m. EDT Monday, July 14, pending weather, to begin their return to Earth and splashdown off the coast of California.
      Coverage of departure operations will begin with hatch closing at 4:30 a.m. on NASA+. Learn how to watch NASA content through a variety of platforms, including social media.
      Peggy Whitson, former NASA astronaut and director of human spaceflight at Axiom Space, ISRO (Indian Space Research Organization) astronaut Shubhanshu Shukla, ESA (European Space Agency) project astronaut Sławosz Uznański-Wiśniewski of Poland, and HUNOR (Hungarian to Orbit) astronaut Tibor Kapu of Hungary, will have spent about two weeks in space at the conclusion of their mission.
      The Dragon spacecraft will return with more than 580 pounds of cargo, including NASA hardware and data from over 60 experiments conducted throughout the mission.
      NASA’s coverage is as follows (all times Eastern and subject to change based on real-time operations):
      Monday, July 14
      4:30 a.m. – Hatch closing coverage begins on NASA+.
      4:55 a.m. – Crew enters spacecraft followed by hatch closing.
      6:45 a.m. – Undocking coverage begins on NASA+, Axiom Space, and SpaceX channels.
      7:05 a.m. – Undocking
      NASA’s coverage ends approximately 30 minutes after undocking when space station joint operations with Axiom Space and SpaceX conclude. Axiom Space will resume coverage of Dragon’s re-entry and splashdown on the company’s website.
      A collaboration between NASA and ISRO allowed Axiom Mission 4 to deliver on a commitment highlighted by President Trump and Indian Prime Minister Narendra Modi to send the first ISRO astronaut to the station. The space agencies participated in five joint science investigations and two in-orbit science, technology, engineering, and mathematics demonstrations. NASA and ISRO have a long-standing relationship built on a shared vision to advance scientific knowledge and expand space collaboration.
      The private mission also carried the first astronauts from Poland and Hungary to stay aboard the space station.
      The International Space Station is a springboard for developing a low Earth orbit economy. NASA’s goal is to achieve a strong economy off the Earth where the agency can purchase services as one of many customers to meet its science and research objectives in microgravity. NASA’s commercial strategy for low Earth orbit provides the government with reliable and safe services at a lower cost, enabling the agency to focus on Artemis missions to the Moon in preparation for Mars while also continuing to use low Earth orbit as a training and proving ground for those deep space missions.
      Learn more about NASA’s commercial space strategy at:
      https://www.nasa.gov/commercial-space
      -end-
      Claire O’Shea
      Headquarters, Washington
      202-358-1100
      claire.a.o’shea@nasa.gov
      Anna Schneider
      Johnson Space Center, Houston
      281-483-5111
      anna.c.schneider@nasa.gov
      Share
      Details
      Last Updated Jul 11, 2025 LocationNASA Headquarters Related Terms
      International Space Station (ISS) Commercial Crew Commercial Space Commercial Space Programs Humans in Space ISS Research Johnson Space Center Space Operations Mission Directorate View the full article
    • By NASA
      2 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Here you see the X-59 scaled model inside the JAXA supersonic wind tunnel during critical tests related to sound predictions.JAXA Researchers from NASA and the Japanese Aerospace Exploration Agency (JAXA) recently tested a scale model of the X-59 experimental aircraft in a supersonic wind tunnel located in Chofu, Japan, to assess the noise audible underneath the aircraft. 
      The test was an important milestone for NASA’s one-of-a-kind X-59, which is designed to fly faster than the speed of sound without causing a loud sonic boom.  
      When the X-59 flies, sound underneath it – a result of its pressure signature – will be a critical factor for what people hear on the ground. 
      The X-59 is 99.7 feet long, with a wingspan of 29.7 feet. The JAXA wind tunnel, on the other hand, is just over 3 feet long by 3 feet wide.  
      So, researchers used a model scaled to just 1.62% of the actual aircraft – about 19 inches nose-to-tail. They exposed it to conditions mimicking the X-plane’s planned supersonic cruising speed of Mach 1.4, or approximately 925 miles per hour. 
      The series of tests performed at JAXA allowed NASA researchers to gather critical experimental data to compare to their predictions derived through Computational Fluid Dynamics modeling, which include how air will flow around the aircraft.  
      This marked the third round of wind tunnel tests for the X-59 model, following a previous test at JAXA and at NASA’s Glenn Research Center in Ohio. 
      The data will help researchers understand the noise level that will be created by the shock waves the X-59 produces at supersonic speeds.  
      The shock waves from traditional supersonic aircraft typically merge together, producing a loud sonic boom. The X-59’s unique design works to keep shock waves from merging, will result in a quieter sonic thump. 
      The X-59 was built in Palmdale, California at contractor Lockheed Martin Skunk Works and is undergoing final ground tests en route to its historic first flight this year.   
      NASA’s Quesst mission aims to help change the future of quiet supersonic travel using the X-59. The experimental aircraft allow the Quesst team to gather public feedback on acceptable sound levels for quiet supersonic flight.  
      Through Quesst’s development of the X-59, NASA will deliver design tools and technology for quiet supersonic airliners that will achieve the high speeds desired by commercial operators without creating disturbance to people on the ground. 
      Facebook logo @NASA@NASAaero@NASAes @NASA@NASAaero@NASA_es Instagram logo @NASA@NASAaero@NASA_es Linkedin logo @NASA Explore More
      6 min read Meet Mineral Mappers Flying NASA Tech Out West
      Article 21 hours ago 3 min read NASA Aircraft, Sensor Technology, Aid in Texas Flood Recovery Efforts
      Article 2 days ago 5 min read NASA Advances Pressure Sensitive Paint Research Capability
      Article 1 week ago Keep Exploring Discover More Topics From NASA
      Missions
      Humans In Space
      Quesst Supersonic STEM Toolkit
      Explore NASA’s History
      Share
      Details
      Last Updated Jul 11, 2025 EditorLillian GipsonContactJim Bankejim.banke@nasa.gov Related Terms
      Aeronautics Aeronautics Research Mission Directorate Low Boom Flight Demonstrator Quesst (X-59) Quesst: The Vehicle Supersonic Flight View the full article
    • By NASA
      The crew of NASA’s SpaceX Crew-11 mission sit inside a Dragon training spacecraft at SpaceX in Hawthorne, California. Pictured from left: Roscosmos cosmonaut Oleg Platonov, NASA astronauts Mike Fincke and Zena Cardman, and JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui (Credit: SpaceX). NASA’s SpaceX Crew-11 mission is set to launch a four-person crew to the International Space Station later this summer. Some of the crew have volunteered to participate in a series of experiments to address health challenges astronauts may face on deep space missions during NASA’s Artemis campaign and future human expeditions to Mars.
      The research during Crew-11 includes simulated lunar landings, tactics to safeguard vision, and other human physiology studies led by NASA’s Human Research Program.
      Select crew members will participate in a series of simulated Moon landings, before, during, and after their flight. Using a handheld controller and multiple screens, the astronauts will fly through simulated scenarios created to resemble the lunar South Pole region that Artemis crews plan to visit. This experiment allows researchers to evaluate how different gravitational forces may disorient astronauts and affect their ability to pilot a spacecraft, like a lunar lander.
      “Even though many landing tasks are automated, astronauts must still know how to monitor the controls and know when to take over to ensure a safe landing,” said Scott Wood, a neuroscientist at NASA’s Johnson Space Center in Houston coordinating the scientific investigation. “Our study assesses exactly how changes in gravity affect spatial awareness and piloting skills that are important for navigating these scenarios.”
      A ground control group completing the same tasks over a similar timeframe will help scientists better understand gravitational effects on human performance. The experiment’s results could inform the pilot training needed for future Artemis crews.
      “Experiencing weightlessness for months and then feeling greater levels of gravity on a planet like Mars, for example, may increase the risk of disorientation,” said Wood. “Our goal is to help astronauts adapt to any gravitational change, whether it’s to the Moon, a new planet, or landing back on Earth.”
      Other studies during the mission will explore possible ways to treat or prevent a group of eye and brain changes that can occur during long-duration space travel, called spaceflight associated neuro-ocular syndrome (SANS).  
      Some researchers suspect the redistribution of bodily fluids in constant weightlessness may increase pressure in the head and contribute to SANS. One study will investigate fluid pressure on the brain while another will examine how the body processes B vitamins and whether supplements can affect how astronauts respond to bodily fluid shifts. Participating crew members will test whether a daily B vitamin supplement can eliminate or ease symptoms of SANS. Specific crew members also will wear thigh cuffs to keep bodily fluids from traveling headward.
      Crew members also will complete another set of experiments, called CIPHER (Complement of Integrated Protocols for Human Exploration Research), which measures how multiple systems within the human body change in space. The study includes vision assessments, MRI scans, and other medical exams to provide a complete overview of the whole body’s response to long-duration spaceflight.
      Several other studies involving human health and performance are also a part of Crew-11’s science portfolio. Crew members will contribute to a core set of measurements called Spaceflight Standard Measures, which collects physical data and biological samples from astronauts and stores them for other comparative studies. Participants will supply biological samples, such as blood and urine, for a study characterizing how spaceflight alters astronauts’ genetic makeup. In addition, volunteers will test different exercise regimens to help scientists explore what activities remain essential for long-duration journeys.
      After landing, participating crew members will complete surveys to track any discomfort, such as scrapes or bruises, acquired from re-entry. The data will help clarify whether mission length increases injury risks and could help NASA design landing systems on future spacecraft as NASA prepares to travel to the Moon, Mars, and beyond.
      NASA’s Human Research Program pursues methods and technologies to support safe, productive human space travel. Through science conducted in laboratories, ground-based analogs, and aboard the International Space Station, the program investigates how spaceflight affects human bodies and behaviors. Such research drives NASA’s quest to innovate ways that keep astronauts healthy and mission-ready.
      Explore More
      2 min read NASA Announces Winners of 2025 Human Lander Challenge
      Article 2 weeks ago 4 min read NASA, Australia Team Up for Artemis II Lunar Laser Communications Test
      Article 2 weeks ago 3 min read NASA Engineers Simulate Lunar Lighting for Artemis III Moon Landing
      Article 3 weeks ago Keep Exploring Discover More Topics From NASA
      Living in Space
      Artemis
      Human Research Program
      Space Station Research and Technology
      View the full article
    • By NASA
      An artist’s concept design of NASA’s Lunar Terrain Vehicle.Credit: NASA NASA has selected three instruments to travel to the Moon, with two planned for integration onto an LTV (Lunar Terrain Vehicle) and one for a future orbital opportunity.
      The LTV is part of NASA’s efforts to explore the lunar surface as part of the Artemis campaign and is the first crew-driven vehicle to operate on the Moon in more than 50 years. Designed to hold up to two astronauts, as well as operate remotely without a crew, this surface vehicle will enable NASA to achieve more of its science and exploration goals over a wide swath of lunar terrain.
      “The Artemis Lunar Terrain Vehicle will transport humanity farther than ever before across the lunar frontier on an epic journey of scientific exploration and discovery,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “By combining the best of human and robotic exploration, the science instruments selected for the LTV will make discoveries that inform us about Earth’s nearest neighbor as well as benefit the health and safety of our astronauts and spacecraft on the Moon.”
      The Artemis Infrared Reflectance and Emission Spectrometer (AIRES) will identify, quantify, and map lunar minerals and volatiles, which are materials that evaporate easily, like water, ammonia, or carbon dioxide. The instrument will capture spectral data overlaid on visible light images of both specific features of interest and broad panoramas to discover the distribution of minerals and volatiles across the Moon’s south polar region. The AIRES instrument team is led by Phil Christensen from Arizona State University in Tempe.
      The Lunar Microwave Active-Passive Spectrometer (L-MAPS) will help define what is below the Moon’s surface and search for possible locations of ice. Containing both a spectrometer and a ground-penetrating radar, the instrument suite will measure temperature, density, and subsurface structures to more than 131 feet (40 meters) below the surface. The L-MAPS instrument team is led by Matthew Siegler from the University of Hawaii at Manoa.
      When combined, the data from the two instruments will paint a picture of the components of the lunar surface and subsurface to support human exploration and will uncover clues to the history of rocky worlds in our solar system. The instruments also will help scientists characterize the Moon’s resources, including what the Moon is made of, potential locations of ice, and how the Moon changes over time.
      In addition to the instruments selected for integration onto the LTV, NASA also selected the Ultra-Compact Imaging Spectrometer for the Moon (UCIS-Moon) for a future orbital flight opportunity. The instrument will provide regional context to the discoveries made from the LTV. From above, UCIS-Moon will map the Moon’s geology and volatiles and measure how human activity affects those volatiles. The spectrometer also will help identify scientifically valuable areas for astronauts to collect lunar samples, while its wide-view images provide the overall context for where these samples will be collected. The UCIS-Moon instrument will provide the Moon’s highest spatial resolution data of surface lunar water, mineral makeup, and thermophysical properties. The UCIS-Moon instrument team is led by Abigail Fraeman from NASA’s Jet Propulsion Laboratory in Southern California.
      “Together, these three scientific instruments will make significant progress in answering key questions about what minerals and volatiles are present on and under the surface of the Moon,” said Joel Kearns, deputy associate administrator for Exploration, Science Mission Directorate at NASA Headquarters. “With these instruments riding on the LTV and in orbit, we will be able to characterize the surface not only where astronauts explore, but also across the south polar region of the Moon, offering exciting opportunities for scientific discovery and exploration for years to come.”
      Leading up to these instrument selections, NASA has worked with all three lunar terrain vehicle vendors – Intuitive Machines, Lunar Outpost, and Venturi Astrolab – to complete their preliminary design reviews. This review demonstrates that the initial design of each commercial lunar rover meets all of NASA’s system requirements and shows that the correct design options have been selected, interfaces have been identified, and verification methods have been described. NASA will evaluate the task order proposals received from each LTV vendor and make a selection decision on the demonstration mission by the end of 2025. 
      Through Artemis, NASA will address high priority science questions, focusing on those that are best accomplished by on-site human explorers on and around the Moon by using robotic surface and orbiting systems. The Artemis missions will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.
      To learn more about Artemis, visit:
      https://www.nasa.gov/artemis
      -end-
      Karen Fox / Molly Wasser
      Headquarters, Washington
      202-358-1600
      karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
      Share
      Details
      Last Updated Jul 10, 2025 LocationNASA Headquarters Related Terms
      Artemis Earth's Moon Science Mission Directorate View the full article
    • By NASA
      7 min read
      NASA’s Parker Solar Probe Snaps Closest-Ever Images to Sun
      KEY POINTS
      NASA’s Parker Solar Probe has taken the closest ever images to the Sun, captured just 3.8 million miles from the solar surface. The new close-up images show features in the solar wind, the constant stream of electrically charged subatomic particles released by the Sun that rage across the solar system at speeds exceeding 1 million miles an hour. These images, and other data, are helping scientists understand the mysteries of the solar wind, which is essential to understanding its effects at Earth. On its record-breaking pass by the Sun late last year, NASA’s Parker Solar Probe captured stunning new images from within the Sun’s atmosphere. These newly released images — taken closer to the Sun than we’ve ever been before — are helping scientists better understand the Sun’s influence across the solar system, including events that can affect Earth.
      “Parker Solar Probe has once again transported us into the dynamic atmosphere of our closest star,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “We are witnessing where space weather threats to Earth begin, with our eyes, not just with models. This new data will help us vastly improve our space weather predictions to ensure the safety of our astronauts and the protection of our technology here on Earth and throughout the solar system.”
      Parker Solar Probe started its closest approach to the Sun on Dec. 24, 2024, flying just 3.8 million miles from the solar surface. As it skimmed through the Sun’s outer atmosphere, called the corona, in the days around the perihelion, it collected data with an array of scientific instruments, including the Wide-Field Imager for Solar Probe, or WISPR. 
      Parker Solar Probe has revolutionized our understanding of the solar wind thanks to the spacecraft’s many passes through the Sun’s outer atmosphere.
      Credit: NASA’s Goddard Space Flight Center/Joy Ng The new WISPR images reveal the corona and solar wind, a constant stream of electrically charged particles from the Sun that rage across the solar system. The solar wind expands throughout of the solar system with wide-ranging effects. Together with outbursts of material and magnetic currents from the Sun, it helps generate auroras, strip planetary atmospheres, and induce electric currents that can overwhelm power grids and affect communications at Earth. Understanding the impact of solar wind starts with understanding its origins at the Sun.
      The WISPR images give scientists a closer look at what happens to the solar wind shortly after it is released from the corona. The images show the important boundary where the Sun’s magnetic field direction switches from northward to southward, called the heliospheric current sheet. It also captures the collision of multiple coronal mass ejections, or CMEs — large outbursts of charged particles that are a key driver of space weather — for the first time in high resolution.
      “In these images, we’re seeing the CMEs basically piling up on top of one another,” said Angelos Vourlidas, the WISPR instrument scientist at the Johns Hopkins Applied Physics Laboratory, which designed, built, and operates the spacecraft in Laurel, Maryland. “We’re using this to figure out how the CMEs merge together, which can be important for space weather.”
      To view this video please enable JavaScript, and consider upgrading to a web browser that
      supports HTML5 video
      This video, made from images taken by Parker Solar Probe’s WISPR instrument during its record-breaking flyby of the Sun on Dec. 25, 2024, shows the solar wind racing out from the Sun’s outer atmosphere, the corona. NASA/Johns Hopkins APL/Naval Research Lab When CMEs collide, their trajectory can change, making it harder to predict where they’ll end up. Their merger can also accelerate charged particles and mix magnetic fields, which makes the CMEs’ effects potentially more dangerous to astronauts and satellites in space and technology on the ground. Parker Solar Probe’s close-up view helps scientists better prepare for such space weather effects at Earth and beyond.
      Zooming in on Solar Wind’s Origins
      The solar wind was first theorized by preeminent heliophysicist Eugene Parker in 1958. His theories about the solar wind, which were met with criticism at the time, revolutionized how we see our solar system. Prior to Parker Solar Probe’s launch in 2018, NASA and its international partners led missions like Mariner 2, Helios, Ulysses, Wind, and ACE that helped scientists understand the origins of the solar wind — but from a distance. Parker Solar Probe, named in honor of the late scientist, is filling in the gaps of our understanding much closer to the Sun.
      At Earth, the solar wind is mostly a consistent breeze, but Parker Solar Probe found it’s anything but at the Sun. When the spacecraft reached within 14.7 million miles from the Sun, it encountered zig-zagging magnetic fields — a feature known as switchbacks. Using Parker Solar Probe’s data, scientists discovered that these switchbacks, which came in clumps, were more common than expected.
      When Parker Solar Probe first crossed into the corona about 8 million miles from the Sun’s surface in 2021, it noticed the boundary of the corona was uneven and more complex than previously thought.
      As it got even closer, Parker Solar Probe helped scientists pinpoint the origin of switchbacks at patches on the visible surface of the Sun where magnetic funnels form. In 2024 scientists announced that the fast solar wind — one of two main classes of the solar wind — is in part powered by these switchbacks, adding to a 50-year-old mystery.
      However, it would take a closer view to understand the slow solar wind, which travels at just 220 miles per second, half the speed of the fast solar wind.
      “The big unknown has been: how is the solar wind generated, and how does it manage to escape the Sun’s immense gravitational pull?” said Nour Rawafi, the project scientist for Parker Solar Probe at the Johns Hopkins Applied Physics Laboratory. “Understanding this continuous flow of particles, particularly the slow solar wind, is a major challenge, especially given the diversity in the properties of these streams — but with Parker Solar Probe, we’re closer than ever to uncovering their origins and how they evolve.”
      Understanding Slow Solar Wind
      The slow solar wind, which is twice as dense and more variable than fast solar wind, is important to study because its interplay with the fast solar wind can create moderately strong solar storm conditions at Earth sometimes rivaling those from CMEs.
      To view this video please enable JavaScript, and consider upgrading to a web browser that
      supports HTML5 video
      This artist’s concept shows a representative state of Earth’s magnetic bubble immersed in the slow solar wind, which averages some 180 to 300 miles per second. NASA’s Goddard Space Flight Center Conceptual Image Lab Prior to Parker Solar Probe, distant observations suggested there are actually two varieties of slow solar wind, distinguished by the orientation or variability of their magnetic fields. One type of slow solar wind, called Alfvénic, has small-scale switchbacks. The second type, called non-Alfvénic, doesn’t show these variations in its magnetic field. 
      As it spiraled closer to the Sun, Parker Solar Probe confirmed there are indeed two types. Its close-up views are also helping scientists differentiate the origins of the two types, which scientists believe are unique. The non-Alfvénic wind may come off features called helmet streamers — large loops connecting active regions where some particles can heat up enough to escape — whereas Alfvénic wind might originate near coronal holes, or dark, cool regions in the corona. 
      In its current orbit, bringing the spacecraft just 3.8 million miles from the Sun, Parker Solar Probe will continue to gather additional data during its upcoming passes through the corona to help scientists confirm the slow solar wind’s origins. The next pass comes Sept. 15, 2025.
      “We don’t have a final consensus yet, but we have a whole lot of new intriguing data,” said Adam Szabo, Parker Solar Probe mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
      By Mara Johnson-Groh
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Share








      Details
      Last Updated Jul 10, 2025 Related Terms
      Heliophysics Goddard Space Flight Center Heliophysics Division Missions NASA Centers & Facilities NASA Directorates Parker Solar Probe (PSP) Science & Research Science Mission Directorate Solar Wind Space Weather Explore More
      8 min read NASA’s Webb Scratches Beyond Surface of Cat’s Paw for 3rd Anniversary


      Article


      5 hours ago
      6 min read Smarter Searching: NASA AI Makes Science Data Easier to Find


      Article


      1 day ago
      2 min read Polar Tourists Give Positive Reviews to NASA Citizen Science in Antarctica


      Article


      1 day ago
      Keep Exploring Discover More Topics From NASA
      Missions



      Humans in Space



      Climate Change



      Solar System


      View the full article
  • Check out these Videos

×
×
  • Create New...