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By Space Force
U.S. Space Force Col. Nick Hague returned to Earth following a six-month mission aboard the International Space Station, March 18, 2025.
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By NASA
A chevron nozzle is installed on NASA’s Learjet for a mid-March 2001 flight test at Lorain Country Airport to verify that in an emergency, the aircraft could be flown using only the experimental engine. Credit: NASA/Marvin Smith
Shortly after dawn on March 27, 2001, NASA pilot Bill Rieke took off from an airfield just outside of Phoenix in NASA’s blue-and-white Learjet 25 and flew low over a series of microphones for the first flight test of a groundbreaking NASA technology.
On one of the plane’s engines was an experimental jagged-edged nozzle that researchers at Glenn Research Center in Cleveland had discovered made aircraft significantly quieter. These initial flight tests were an important step toward using these “chevron nozzles” on modern aircraft, lowering noise levels for communities.
NASA Glenn has been exploring ways of reducing engine noise since the first jet airliners appeared in the 1950s. New turbofan engines in the 1960s were quieter, but the expansion of the overall airline industry meant that noise was still an issue. With the introduction of noise-limiting mandates in the 1970s, NASA and engine manufacturers embarked on a decades-long search for technologies to lower noise levels.
NASA researchers discovered that the military’s use of rectangular notches, or tabs, along an engine nozzle’s exit – to help disguise a jet fighter’s infrared signature – could also reduce engine noise by helping mix the hot air from the engine core and the cooler air blowing through the engine fan. In the 1990s, Glenn researcher Dennis Huff and his colleagues discovered that a serrated, or sawtooth, shape, referred to as a chevron, offered more promise.
Dennis Huff explains chevron nozzles, seen on a table, to U.S. Senator George Voinovich and other visitors inside the Aero-Acoustic Propulsion Laboratory facility in 2006. Huff was head of NASA Glenn Research Center’s Acoustics Branch at this point.Credit: NASA/Marvin Smith NASA contracted with General Electric and Pratt & Whitney to develop an array of tab and chevron designs to be analyzed in Glenn’s unique Aero-Acoustic Propulsion Laboratory (AAPL). Extensive testing in the spring of 1997 showed the possibilities for reducing noise with these types of nozzles.
Engine manufacturers were impressed with the findings but wary of any technology that might impact performance. So, in 1998, NASA funded engine tests of the 14 most promising designs. The tests revealed the chevron nozzle had a negligible 0.25% reduction of thrust. It was a major development for jet noise research.
In September 2000, Glenn’s Flight Operations Branch was contacted about the logistics of flight-testing chevron nozzles on the center’s Learjet 25 to verify the ground tests and improve computer modeling. Nothing further came of the request, however, until early the next year when Huff informed Rieke, chief of Flight Operations, that the researchers would like to conduct flight tests in late March—with just eight weeks to prepare.
Glenn’s Acoustics Branch worked with colleagues at NASA’s Langley Research Center in Hampton, Virginia, and the Arizona-based engine manufacturer Honeywell on the effort. They planned to conduct testing at Estrella Sailport just outside of Phoenix from March 26 to 28, 2001.
Bill Rieke and Ellen Tom with the chevron nozzle installed on the Learjet. NASA Glenn Research Center’s small Flight Operations team was heavily involved with icing research and solar cell calibration flights during this period, so arrangements were made for Tom, a Federal Aviation Administration pilot, to assist with the chevron flights. Credit: Courtesy of Bill Rieke With the required safety and design reviews, the eight-week target date would be difficult to meet for any test flight, but this one was particularly challenging as it involved modifications to the engine nacelle. While the special nozzle engineers created for the flights would allow them to switch between a six- and a 12-chevron design during testing, it also got hot quickly. This necessitated the installation of new sensors, rewiring of fire alarm cables, and the presence of an onboard test engineer to monitor the temperatures. The short turnaround also required expedited efforts to obtain flight plan approvals, verify the plane’s airworthiness, and perform normal maintenance activities.
Despite the challenges, Rieke and a small team delivered the Learjet to Estrella on March 25, as planned. The next day was spent coordinating with the large Langley and Honeywell team and acquiring baseline noise data. The pilots idled the unmodified engine as the Learjet flew over three perpendicular rows of microphones at an altitude of 500 feet and speed of 230 miles per hour.
View from below as NASA Glenn Research Center’s Learjet 25 passes overhead at the Estrella airfield with the experimental chevron nozzle visible on the left wing.Credit: Courtesy of Bill Rieke The flight patterns were repeated over the next two days while alternately using the two variations of the chevron nozzle. The researchers anecdotally reported that there was no perceptible noise reduction as the aircraft approached, but significant reductions once it passed. Recordings supported these observations and showed that sideline noise was reduced, as well.
The flights of the Learjet, which was powered by a variation of GE’s J-85 turbojet, were complemented by Honeywell’s turbofan-powered Falcon 20 aircraft. These flights ultimately confirmed the noise reduction found in earlier AAPL tests.
Overall, the flight tests were so successful that just over a year later the FAA began certifying GE’s CF34–8, the first commercial aircraft engine to incorporate chevron technology. The engine was first flown on a Bombardier CRJ900 in 2003. Continued studies by both NASA and industry led to the improved designs and the incorporation of chevrons into larger engines, such as GE’s GEnx.
According to Huff, the chevron’s three-decibel noise decrease was analogous to the difference between running two lawnmowers and one. Their comparatively easy integration into engine design and minimal effect on thrust made the chevron a breakthrough in noise-reduction technology. In 2002, NASA presented an innovation award to the Glenn, Langley, and Honeywell team that carried out the flights. Today, airliners such as the 737 MAX and 787 Dreamliner use chevron nozzles to lower noise levels for communities near airports.
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By USH
EBANI stands for "Unidentified Anomalous Biological Entity," referring to a mysterious class of airborne phenomena that may be biological rather than mechanical in nature. These entities are often described as elongated, flexible, and tubular, moving through the sky in a serpentine or twisting manner.
They exhibit advanced flight capabilities, including high-speed travel, precise control, and even self-illumination. Some have been observed rendering themselves invisible, raising questions about their energy sources and possible technological origins.
Recent observations have revealed formations of translucent spheres in red, white, and blue, challenging conventional classifications of both biology and aerodynamics.
Some of these entities have a massive structure composed of thousands of clustered spheres. These entities appear to function as an aircraft carrier, releasing these smaller spheres into Earth's atmosphere for an unknown purpose.
While some researchers propose that EBANIs are natural organisms evolving in Earth's upper atmosphere under unfamiliar physical laws, others speculate they may be advanced artificial (eventually biological) constructs, potentially extraterrestrial probes or surveillance devices, given the presence of large structures expelling numerous smaller spheres.
Are they living UFOs, advanced biological organisms that function autonomously within the spheres, without the need for pilots?
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By European Space Agency
The third Copernicus Sentinel-1 satellite was launched on a Vega-C rocket from Europe’s Spaceport in French Guiana. Sentinel-1C extends the legacy of its predecessors, delivering high-resolution radar imagery to monitor Earth’s changing environment, supporting a diverse range of applications and advancing scientific research. Additionally, Sentinel-1C introduces new capabilities for detecting and monitoring maritime traffic.
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By NASA
Earth (ESD) Earth Explore Climate Change Science in Action Multimedia Data For Researchers About Us 6 min read
NASA Flights Map Critical Minerals from Skies Above Western US
Various minerals are revealed in vibrant detail in this sample mineral map of Cuprite, Nevada, following processing of imaging spectrometer data. USGS On a crystal-clear afternoon above a desert ghost town, a NASA aircraft scoured the ground for minerals.
The plane, a high-altitude ER-2 research aircraft, had taken off early that morning from NASA’s Armstrong Flight Research Center in Edwards, California. Below pilot Dean Neeley, the landscape looked barren and brown. But to the optical sensors installed on the plane’s belly and wing, it gleamed in hundreds of colors.
Neeley’s flight that day was part of GEMx, the Geological Earth Mapping Experiment led by NASA and the U.S. Geological Survey to map critical minerals across more than 190,000 square miles (500,000 square kilometers) of North American soil. Using airborne instruments, scientists are collecting these measurements over parts of California, Nevada, Arizona, and Oregon. That’s an area about the size of Spain.
An ER-2 science aircraft banks away during a flight over the southern Sierra Nevada. The high-altitude plane supports a wide variety of research missions, including the GEMx campaign, which is mapping critical minerals in the Western U.S. using advanced airborne imaging developed by NASA. Credit: NASA/Carla Thomas Lithium, aluminum, rare earth elements such as neodymium and cerium — these are a few of the 50 mineral commodities deemed essential to U.S. national security, to the tech industry, and to clean energy. They support a wide range of technologies from smartphones to steelmaking, from wind turbines to electric vehicle batteries. In 2023, the U.S. imported its entire supply of 12 of these minerals and imported at least 50% of its supply of another 29.
The GEMx team believes that undiscovered deposits of at least some of these minerals exist domestically, and modern mineral maps will support exploration by the private sector.
“We’ve been exploring the earth beneath our feet for hundreds of years, and we’re discovering that we’ve only just begun,” said Kevin Reath, NASA’s associate project manager for GEMx.
The View From 65,000 Feet
To jumpstart mineral exploration, USGS is leading a nationwide survey from the inside out, using tools like lidar and magnetic-radiometric sensors to probe ancient terrain in new detail.
The collaboration with NASA brings another tool to bear: imaging spectrometers. These advanced optical instruments need to stay cold as they fly high. From cryogenic vacuum chambers on planes or spacecraft, they detect hundreds of wavelengths of light — from the visible to shortwave infrared — reflected off planetary surfaces. The technology is now being used to help identify surface minerals across dry, treeless expanses of the Western U.S.
Every molecule reflects a unique pattern of light, like a fingerprint. Processed through a spectroscopic lens, a desert expanse can appear like an oil painting popping with different colorful minerals, including pale-green mica, blue kaolinite, and plummy gypsum.
“We’re not digging for gold. We’re revealing what’s hidden in plain sight,” said Robert Green, a researcher at NASA’s Jet Propulsion Laboratory in Southern California, who helped pioneer spectroscopic imaging at NASA JPL in the late 1970s. Like many of the scientists involved with GEMx, he has spent years surveying other worlds, including the Moon and Mars.
A handful of such instruments exist on Earth, and Green is in charge of two of them. One, called EMIT (Earth Surface Mineral Dust Source Investigation) flies aboard the International Space Station. Surveying Earth’s surface from about 250 miles (410 kilometers) above, EMIT has captured thousands of images at a resolution of 50 by 50 miles (80 by 80 kilometers) in a wide belt around Earth’s mid-section.
The other instrument rides beneath the fuselage of the ER-2 aircraft. Called AVIRIS (Airborne Visible/Infrared Imaging Spectrometer), it’s helping guide geologists to critical minerals directly and indirectly, by spotting the types of rocks that often contain them. It’s joined by another instrument developed by NASA, the MODIS/ASTER Airborne Simulator (MASTER), which senses thermal infrared radiance. Both instruments provide finely detailed measurements of minerals that complement what EMIT sees on a broader scale.
A crew of life support staff prepare pilot Dean Neeley for an ER-2 flight. A specialized suit – similar to an astronaut’s – allows the pilot to work, breathe, and eat at altitudes almost twice as high as a cruising passenger jet. NASA/Carla Thomas Old Mines, New Finds
In and around the multimillion-year-old magmas of the Great Basin of the Western U.S., lithium takes several forms. The silvery metal is found in salty brines, in clay, and locked in more than 100 different types of crystals. It can also be detected in the tailings of abandoned prospects like Hector Mine, near Barstow, California.
Abandoned years before a magnitude 7.1 earthquake rocked the region in 1999, the mine is located on a lode of hectorite, a greasy, lithium-bearing clay. Geologists from USGS are taking a second look at legacy mines like Hector as demand for lithium rises, driven primarily by lithium-ion batteries. A typical battery pack in an electric vehicle uses about 17 pounds (eight kilograms) of the energy-dense metal.
Australia and Chile lead worldwide production of lithium, which exceeded 180,000 tons in 2023. The third largest producer is China, which also hosts about 50% of global lithium refining capacity. Total U.S. production was around 1,000 tons, sourced entirely from a deposit in northern Nevada. Known reserves in the state are estimated to contain more than a million metric tons of lithium, according to data collected by the Nevada Bureau of Mines and Geology.
Mine wastes are also potential sources of lithium, said Bernard Hubbard, a remote sensing geologist at USGS, and many other byproduct commodities that are considered critical today but were discarded by previous generations.
“There are old copper and silver mines in the West that were abandoned long before anyone knew what lithium or rare earth element deposits were,” Hubbard said. “What has been a pollution source for communities could now be a resource.”
Following a winter pause, high-altitude GEMx flights over the American West will resume in the spring of 2025, after which USGS will process the raw data and release the first mineral maps. Already, the project has collected enough data to start producing a complete hyperspectral map of California — the first of its kind.
The value of these observations extends beyond identifying minerals. Scientists expect they’ll provide new insight into invasive plant species, waste from mines that can contaminate surrounding environments, and natural hazards such as earthquakes, landslides, and wildfires.
“We are just beginning to scratch the surface in applying these measurements to help the nation’s economy, security, and health,” said Raymond Kokaly, USGS research geophysicist and lead of the GEMx survey.
More About GEMx
The GEMx research project will last four years and is funded by the USGS Earth Mapping Resources Initiative (EarthMRI), through investments from the Bipartisan Infrastructure Law. The initiative will capitalize on both the technology developed by NASA for spectroscopic imaging as well as the expertise in analyzing the datasets and extracting critical mineral information from them.
Data collected by GEMx is available here.
By Sally Younger
NASA’s Earth Science News Team
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Last Updated Dec 05, 2024 Contact Sally Younger Related Terms
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