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By NASA
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Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA Marshall will hold a candle-lighting ceremony and wreath placement at 9:30 a.m. CST. The ceremony will include remarks from Larry Leopard, associate director, and Bill Hill, director of Marshall’s Office of Safety and Mission Assurance. NASA/ Krisdon Manecke NASA’s Marshall Space Flight Center in Huntsville, Alabama, invites media to attend its observance of the agency’s Day of Remembrance at 9:30 a.m. CST Thursday, Jan. 23, in the lobby of Building 4221.
Day of Remembrance honors the members of the NASA family who lost their lives while furthering the cause of exploration and discovery.
The event will include brief remarks from NASA Marshall leaders, followed by a candle lighting and moment of silence for the crews of Apollo 1 and space shuttles Challenger and Columbia. Speakers will include:
Larry Leopard, associate director, technical. Bill Hill, director, Office of Safety and Mission Assurance. Media interested in attending the event must confirm by 12 p.m. Wednesday, Jan. 22, with Molly Porter at: molly.a.porter@nasa.gov.
The agency will also pay tribute to its fallen astronauts with special online content, updated on NASA’s Day of Remembrance, at:
https://www.nasa.gov/dor/
Molly Porter
Marshall Space Flight Center, Huntsville, Ala.
256-424-5158
molly.a.porter@nasa.gov
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Last Updated Jan 21, 2025 EditorBeth RidgewayContactMolly Portermolly.a.porter@nasa.govLocationMarshall Space Flight Center Related Terms
Marshall Space Flight Center Explore More
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By NASA
NASA’s Jet Propulsion Laboratory used radar data taken by ESA’s Sentinel-1A satellite before and after the 2015 eruption of the Calbuco volcano in Chile to create this inter-ferogram showing land deformation. The color bands west of the volcano indicate land sinking. NISAR will produce similar images.ESA/NASA/JPL-Caltech A SAR image — like ones NISAR will produce — shows land cover on Mount Okmok on Alaska’s Umnak Island . Created with data taken in August 2011 by NASA’s UAVSAR instrument, it is an example of polarimetry, which measures return waves’ orientation relative to that of transmitted signals.NASA/JPL-Caltech Data from NASA’s Magellan spacecraft, which launched in 1989, was used to create this image of Crater Isabella, a 108-mile-wide (175-kilometer-wide) impact crater on Venus’ surface. NISAR will use the same basic SAR principles to measure properties and characteristics of Earth’s solid surfaces.NASA/JPL-Caltech Set to launch within a few months, NISAR will use a technique called synthetic aperture radar to produce incredibly detailed maps of surface change on our planet.
When NASA and the Indian Space Research Organization’s (ISRO) new Earth satellite NISAR (NASA-ISRO Synthetic Aperture Radar) launches in coming months, it will capture images of Earth’s surface so detailed they will show how much small plots of land and ice are moving, down to fractions of an inch. Imaging nearly all of Earth’s solid surfaces twice every 12 days, it will see the flex of Earth’s crust before and after natural disasters such as earthquakes; it will monitor the motion of glaciers and ice sheets; and it will track ecosystem changes, including forest growth and deforestation.
The mission’s extraordinary capabilities come from the technique noted in its name: synthetic aperture radar, or SAR. Pioneered by NASA for use in space, SAR combines multiple measurements, taken as a radar flies overhead, to sharpen the scene below. It works like conventional radar, which uses microwaves to detect distant surfaces and objects, but steps up the data processing to reveal properties and characteristics at high resolution.
To get such detail without SAR, radar satellites would need antennas too enormous to launch, much less operate. At 39 feet (12 meters) wide when deployed, NISAR’s radar antenna reflector is as wide as a city bus is long. Yet it would have to be 12 miles (19 kilometers) in diameter for the mission’s L-band instrument, using traditional radar techniques, to image pixels of Earth down to 30 feet (10 meters) across.
Synthetic aperture radar “allows us to refine things very accurately,” said Charles Elachi, who led NASA spaceborne SAR missions before serving as director of NASA’s Jet Propulsion Laboratory in Southern California from 2001 to 2016. “The NISAR mission will open a whole new realm to learn about our planet as a dynamic system.”
Data from NASA’s Magellan spacecraft, which launched in 1989, was used to create this image of Crater Isabella, a 108-mile-wide (175-kilometer-wide) impact crater on Venus’ surface. NISAR will use the same basic SAR principles to measure properties and characteristics of Earth’s solid surfaces.NASA/JPL-Caltech How SAR Works
Elachi arrived at JPL in 1971 after graduating from Caltech, joining a group of engineers developing a radar to study Venus’ surface. Then, as now, radar’s allure was simple: It could collect measurements day and night and see through clouds. The team’s work led to the Magellan mission to Venus in 1989 and several NASA space shuttle radar missions.
An orbiting radar operates on the same principles as one tracking planes at an airport. The spaceborne antenna emits microwave pulses toward Earth. When the pulses hit something — a volcanic cone, for example — they scatter. The antenna receives those signals that echo back to the instrument, which measures their strength, change in frequency, how long they took to return, and if they bounced off of multiple surfaces, such as buildings.
This information can help detect the presence of an object or surface, its distance away, and its speed, but the resolution is too low to generate a clear picture. First conceived at Goodyear Aircraft Corp. in 1952, SAR addresses that issue.
“It’s a technique to create high-resolution images from a low-resolution system,” said Paul Rosen, NISAR’s project scientist at JPL.
As the radar travels, its antenna continuously transmits microwaves and receives echoes from the surface. Because the instrument is moving relative to Earth, there are slight changes in frequency in the return signals. Called the Doppler shift, it’s the same effect that causes a siren’s pitch to rise as a fire engine approaches then fall as it departs.
Computer processing of those signals is like a camera lens redirecting and focusing light to produce a sharp photograph. With SAR, the spacecraft’s path forms the “lens,” and the processing adjusts for the Doppler shifts, allowing the echoes to be aggregated into a single, focused image.
Using SAR
One type of SAR-based visualization is an interferogram, a composite of two images taken at separate times that reveals the differences by measuring the change in the delay of echoes. Though they may look like modern art to the untrained eye, the multicolor concentric bands of interferograms show how far land surfaces have moved: The closer the bands, the greater the motion. Seismologists use these visualizations to measure land deformation from earthquakes.
Another type of SAR analysis, called polarimetry, measures the vertical or horizontal orientation of return waves relative to that of transmitted signals. Waves bouncing off linear structures like buildings tend to return in the same orientation, while those bouncing off irregular features, like tree canopies, return in another orientation. By mapping the differences and the strength of the return signals, researchers can identify an area’s land cover, which is useful for studying deforestation and flooding.
Such analyses are examples of ways NISAR will help researchers better understand processes that affect billions of lives.
“This mission packs in a wide range of science toward a common goal of studying our changing planet and the impacts of natural hazards,” said Deepak Putrevu, co-lead of the ISRO science team at the Space Applications Centre in Ahmedabad, India.
Learn more about NISAR at:
https://nisar.jpl.nasa.gov
News Media Contacts
Andrew Wang / Jane J. Lee
Jet Propulsion Laboratory, Pasadena, Calif.
626-379-6874 / 818-354-0307
andrew.wang@jpl.nasa.gov / jane.j.lee@jpl.nasa.gov
2025-006
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Last Updated Jan 21, 2025 Related Terms
NISAR (NASA-ISRO Synthetic Aperture Radar) Earth Earth Science Earth Science Division Jet Propulsion Laboratory Explore More
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By European Space Agency
Image: This Copernicus Sentinel-2 image captures the borders between North and South Dakota and Minnesota blanketed with snow and ice. View the full article
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By NASA
The Space Shuttle Columbia and Space Shuttle Challenger Memorials are seen after a wreath laying ceremony that was part of NASA’s Day of Remembrance, Thursday, Jan. 26, 2023, at Arlington National Cemetery in Arlington, Virginia. (Credit: NASA) NASA will observe its annual Day of Remembrance on Thursday, Jan. 23, honoring the members of the NASA family who lost their lives in the pursuit of exploration and discovery for benefit of humanity. The event, traditionally held every year on the fourth Thursday of January, remembers the crews of Apollo 1 and the space shuttles Challenger and Columbia.
“On NASA’s Day of Remembrance, we pause to reflect on the bravery, dedication, and selflessness of the extraordinary individuals who pushed the boundaries of exploration and discovery,” said NASA Associate Administrator Jim Free. “Their legacies remind us of the profound responsibility we have to carry their dreams forward while ensuring safety remains our guiding principle.”
Free will lead an observance at 1 p.m. EST at Arlington National Cemetery in Virginia, which will begin with a wreath-laying ceremony at the Tomb of the Unknown Soldier, followed by observances for the Apollo 1, Challenger, and Columbia crews.
Several agency centers also will hold observances for NASA Day of Remembrance:
Johnson Space Center in Houston
NASA Johnson will hold a commemoration at 10 a.m. CST at the Astronaut Memorial Grove with remarks by Center Director Vanessa Wyche. The event will have a moment of silence, a NASA T-38 flyover, taps performed by the Texas A&M Squadron 17, and a procession placing flowers at Apollo I, Challenger, and Columbia memorial trees.
Kennedy Space Center in Florida
NASA Kennedy and the Astronauts Memorial Foundation will host a ceremony at the Space Mirror Memorial at Kennedy’s Visitor Complex at 10 a.m. EST. The event will include remarks from Tal Ramon, son of Israeli astronaut Ilan Ramon, space shuttle Columbia.
Kelvin Manning, deputy director at NASA Kennedy, also will provide remarks during the ceremony, which will livestream on the center’s Facebook page.
Ames Research Center in California’s Silicon Valley
NASA Ames will hold a remembrance ceremony at 1 p.m. PST that includes remarks from Center Director Eugene Tu, a moment of silence, and bell ringing commemoration.
Glenn Research Center in Cleveland
NASA Glenn will observe Day of Remembrance with remarks at 1 p.m. EST from Center Director Jimmy Kenyon followed by wreath placement, moment of silence, and taps at Lewis Field.
Langley Research Center in Hampton, Virginia
NASA Langley will hold a remembrance ceremony with Acting Center Director Dawn Schaible followed by placing flags at the Langley Workers Memorial.
Marshall Space Flight Center in Huntsville, Alabama
NASA Marshall will hold a candle-lighting ceremony and wreath placement at 9:30 a.m. CST. The ceremony will include remarks from Larry Leopard, associate director, and Bill Hill, director of Marshall’s Office of Safety and Mission Assurance.
Stennis Space Flight Center in Bay St. Louis, Mississippi
NASA Stennis and the NASA Shared Services Center will hold a wreath-laying ceremony at 9 a.m. CST with remarks from Center Director John Bailey and Anita Harrell, NASA Shared Services Center executive director.
The agency also is paying tribute to its fallen astronauts with special online content, updated on NASA’s Day of Remembrance, at:
https://www.nasa.gov/dor
-end-
Abbey Donaldson
Headquarters, Washington
202-358-1600
Abbey.a.donaldson@nasa.gov
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Last Updated Jan 16, 2025 LocationNASA Headquarters View the full article
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By European Space Agency
Three InCubed satellites have launched from the Vandenberg Space Force Base, California, highlighting ESA’s role as partner to industry and its support for business and technology innovation.
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