The James Webb Space Telescope

Posing in the wind tunnel. Via NASA Langley.

New Gravity Map Gives Best View Yet Inside Mars

A new map of Mars' gravity made with three NASA spacecraft is the most detailed to date, providing a revealing glimpse into the hidden interior of the Red Planet.

"Gravity maps allow us to see inside a planet, just as a doctor uses an X-ray to see inside a patient," said Antonio Genova of the Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts. "The new gravity map will be helpful for future Mars exploration, because better knowledge of the planet's gravity anomalies helps mission controllers insert spacecraft more precisely into orbit about Mars. Furthermore, the improved resolution of our gravity map will help us understand the still-mysterious formation of specific regions of the planet." Genova, who is affiliated with MIT but is located at NASA's Goddard Space Flight Center in Greenbelt, Maryland, is the lead author of a paper on this research published online March 5 in the journal Icarus.

The improved resolution of the new gravity map suggests a new explanation for how some features formed across the boundary that divides the relatively smooth northern lowlands from heavily cratered southern highlands. Also, the team confirmed that Mars has a liquid outer core of molten rock by analyzing tides in the Martian crust and mantle caused by the gravitational pull of the sun and the two moons of Mars. Finally, by observing how Mars' gravity changed over 11 years – the period of an entire cycle of solar activity -- the team inferred the massive amount of carbon dioxide that freezes out of the atmosphere onto a Martian polar ice cap when it experiences winter. They also observed how that mass moves between the south pole and the north pole with the change of season in each hemisphere.

The map was derived using Doppler and range tracking data collected by NASA's Deep Space Network from three NASA spacecraft in orbit around Mars: Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). Like all planets, Mars is lumpy, which causes the gravitational pull felt by spacecraft in orbit around it to change. For example, the pull will be a bit stronger over a mountain, and slightly weaker over a canyon.

Slight differences in Mars' gravity changed the trajectory of the NASA spacecraft orbiting the planet, which altered the signal being sent from the spacecraft to the Deep Space Network. These small fluctuations in the orbital data were used to build a map of the Martian gravity field.

The gravity field was recovered using about 16 years of data that were continuously collected in orbit around Mars. However, orbital changes from uneven gravity are tiny, and other forces that can perturb the motion of the spacecraft had to be carefully accounted for, such as the force of sunlight on the spacecraft's solar panels and drag from the Red Planet's thin upper atmosphere. It took two years of analysis and computer modeling to remove the motion not caused by gravity.

"With this new map, we've been able to see gravity anomalies as small as about 100 kilometers (about 62 miles) across, and we've determined the crustal thickness of Mars with a resolution of around 120 kilometers (almost 75 miles)," said Genova. "The better resolution of the new map helps interpret how the crust of the planet changed over Mars' history in many regions."

For example, an area of lower gravity between Acidalia Planitia and Tempe Terra was interpreted before as a system of buried channels that delivered water and sediments from Mars' southern highlands into the northern lowlands billions of years ago when the Martian climate was wetter than it is today. The new map reveals that this low gravity anomaly is definitely larger and follows the boundary between the highlands and the lowlands. This system of gravity troughs is unlikely to be only due to buried channels because in places the region is elevated above the surrounding plains. The new gravity map shows that some of these features run perpendicular to the local topography slope, against what would have been the natural downhill flow of water.

An alternative explanation is that this anomaly may be a consequence of a flexure or bending of the lithosphere -- the strong, outermost layer of the planet -- due to the formation of the Tharsis region. Tharsis is a volcanic plateau on Mars thousands of miles across with the largest volcanoes in the solar system. As the Tharsis volcanoes grew, the surrounding lithosphere buckled under their immense weight.

The new gravity field also allowed the team to confirm indications from previous gravity solutions that Mars has a liquid outer core of molten rock. The new gravity solution improved the measurement of the Martian tides, which will be used by geophysicists to improve the model of Mars' interior.

Changes in Martian gravity over time have been previously measured using the MGS and ODY missions to monitor the polar ice caps. For the first time, the team used MRO data to continue monitoring their mass. The team has determined that when one hemisphere experiences winter, approximately 3 trillion to 4 trillion tons of carbon dioxide freezes out of the atmosphere onto the northern and southern polar caps, respectively. This is about 12 to 16 percent of the mass of the entire Martian atmosphere. NASA's Viking missions first observed this massive seasonal precipitation of carbon dioxide. The new observation confirms numerical predictions from the Mars Global Reference Atmospheric Model – 2010.

The research was funded by grants from NASA's Mars Reconnaissance Orbiter mission and NASA's Mars Data Analysis Program.

Bill Steigerwald

Computational Facility Named After Langley "Human Computer" Katherine Johnson

A smiling Katherine Johnson returned Thursday to the NASA center where, for decades, she used her mathematical smarts to help shape history.

This time she was in the spotlight, not behind a desk making complex calculations and searching for the truth in numbers.

Katherine Johnson worked at NASA's Langley Research Center from 1953 to 1986. Since her retirement, she's been a strong advocate for science, technology, engineering and math (STEM) education.Credits: NASA/David C. Bowman

The mathematician and 97-year-old Newport News resident visited NASA’s Langley Research Center in Hampton, Virginia, to attend a ceremony where a $30 million, 40,000-square-foot Computational Research Facility was named in her honor.

As part of the event, Johnson also received a Silver Snoopy award from Leland Melvin, an astronaut and former NASA associate administrator for education. Often called the astronaut’s award, the Silver Snoopy goes to people who have made outstanding contributions to flight safety and mission success.

“I do thank you so much for your attention, for your kindness, but more than that, I’m so happy to see you giving more recognition to women for the work that they have done,” Johnson said. “I have always done my best … At the time it was just another day’s work.”

Johnson needn’t have been modest. She’s a Presidential Medal of Freedom winnerwhose sharp mind gave NASA an edge in mankind’s quest to explore space.

She first made her mark at a time when women and African-Americans were regularly marginalized.

Working at Langley from 1953 until her retirement in 1986, Johnson made a long list of critical contributions. She calculated the trajectory of the 1961 flight of Alan Shepard, the first American in space. Thursday’s ceremony was held on the 55th anniversary of that historic flight.

Johnson is also credited for verifying the calculations made by early electronic computers of John Glenn’s 1962 launch to orbit and the 1969 Apollo 11 trajectory to the moon.

Margot Lee Shetterly, author of a forthcoming book about Johnson and other women whose calculations were integral to America’s space program, gave the keynote address at Thursday’s event.

Her book, “Hidden Figures:  The American Dream and the Untold Story of the Black Women Mathematicians Who Helped NASA and the United States Win the Space Race,” is scheduled to be published in September by William Morrow.

Shetterly noted that Johnson eagerly credits others who share her passion for what’s now called STEM, short for science, technology, engineering and math.

In that spirit, Shetterly reviewed contributions of other notable NASA Langley women: Dorothy Vaughan, Margery Hannah and Christine Darden.

“This is one of the reasons why Mrs. Johnson’s story has captivated us,” Shetterly said. “She has such a towering talent but she has gone out of her way to recognize talent in other people.”

Hollywood is preparing to tell Johnson’s story. A film version of “Hidden Figures” starring Kirsten Dunst, Kevin Costner and Taraji P. Henson is now being produced by 20th Century Fox.

“I want to congratulate you, Mrs. Katherine Goble Johnson, Mrs. Queen Johnson, the brilliant mind, Mrs. Johnson, for the naming of the building, rightfully deserved,” said actress Henson, in a recorded video message played during the ceremony. Henson will portray Johnson in the film.

“You deserve it. They should name NASA after you! Thank you for your service.”

The Katherine G. Johnson Computational Research Facility under construction at NASA Langley is nearly one-fourth complete and is expected to open in 2017. The third new building in the center’s 20-year revitalization plan, it will allow the center to consolidate the majority of its data centers in one location.

Rep. Bobby Scott and Hampton Mayor George Wallace spoke at Thursday’s naming ceremony. Rep. Scott Rigell sent a representative who offered his congratulations. Sen. Tim Kaine sent a video greeting. A letter from NASA Administrator Charlie Bolden was read aloud.

“I am told you once remarked that, even though you grew up in the height of segregation, you did not have time to think about your place in history and that you never had a feeling of inferiority,” Bolden wrote. “Instead you considered yourself, as you described it, ‘as good as anybody, but no better.’

“The truth of the matter is that you are better. You are one of the greatest minds ever to grace our agency or our country and because of your mind, heart, and soul, my own granddaughters and young Americans like them can pursue their own dreams without a feeling of inferiority."

Rep. Scott said he's happy that Johnson's remarkable contributions are finally getting the exposure they deserve. He's looking forward to seeing them splashed across the big screen.

"I enjoy comedies and thrillers like anybody else," he said, "but Dr. Johnson's story is one that we ought to be telling our children."

See a video on Katherine Johnson's legacy.

See more photos from Thursday's event at a Flickr gallery.

Homeschool Day Brings STEM Activities to Virginia Air & Space Center

Jacob Earley, left, Frank Jones and his mother, Maria Jones, learned about the effects of gravity on other planets from NASA intern Jessica Hathaway during Homeschool Appreciation Day, which took place May 6 at the Virginia Air & Space Center (VASC) in Hampton, Virginia. Hathaway was one of several volunteers from NASA's Langley Research Center in Hampton who taught homeschooled children and their parents interactive lessons about everything from ultraviolet radiation to engineering satellites to navigating a rover on Mars. Approximately 300 people registered for the event, which has a focus on activities involving science, technology, engineering and math (STEM). The VASC is the official visitor center for NASA Langley.

Joe Atkinson NASA Langley Research Center

5 Out-of-This World Technologies Developed for Our Webb Space Telescope

Our James Webb Space Telescope is the most ambitious and complex space science observatory ever built. It will study every phase in the history of our universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

In order to carry out such a daring mission, many innovative and powerful new technologies were developed specifically to enable Webb to achieve its primary mission.  

Here are 5 technologies that were developed to help Webb push the boundaries of space exploration and discovery:

1. Microshutters

Microshutters are basically tiny windows with shutters that each measure 100 by 200 microns, or about the size of a bundle of only a few human hairs. 

The microshutter device will record the spectra of light from distant objects (spectroscopy is simply the science of measuring the intensity of light at different wavelengths. The graphical representations of these measurements are called spectra.)

Other spectroscopic instruments have flown in space before but none have had the capability to enable high-resolution observation of up to 100 objects simultaneously, which means much more scientific investigating can get done in less time. 

Read more about how the microshutters work HERE.

2. The Backplane

Webb’s backplane is the large structure that holds and supports the big hexagonal mirrors of the telescope, you can think of it as the telescope’s “spine”. The backplane has an important job as it must carry not only the 6.5 m (over 21 foot) diameter primary mirror plus other telescope optics, but also the entire module of scientific instruments. It also needs to be essentially motionless while the mirrors move to see far into deep space. All told, the backplane carries more than 2400kg (2.5 tons) of hardware.

This structure is also designed to provide unprecedented thermal stability performance at temperatures colder than -400°F (-240°C). At these temperatures, the backplane was engineered to be steady down to 32 nanometers, which is 1/10,000 the diameter of a human hair!

Read more about the backplane HERE.

3. The Mirrors

One of the Webb Space Telescope’s science goals is to look back through time to when galaxies were first forming. Webb will do this by observing galaxies that are very distant, at over 13 billion light years away from us. To see such far-off and faint objects, Webb needs a large mirror. 

Webb’s scientists and engineers determined that a primary mirror 6.5 meters across is what was needed to measure the light from these distant galaxies. Building a mirror this large is challenging, even for use on the ground. Plus, a mirror this large has never been launched into space before! 

If the Hubble Space Telescope’s 2.4-meter mirror were scaled to be large enough for Webb, it would be too heavy to launch into orbit. The Webb team had to find new ways to build the mirror so that it would be light enough - only 1/10 of the mass of Hubble’s mirror per unit area - yet very strong. 

Read more about how we designed and created Webb’s unique mirrors HERE.

4. Wavefront Sensing and Control

Wavefront sensing and control is a technical term used to describe the subsystem that was required to sense and correct any errors in the telescope’s optics. This is especially necessary because all 18 segments have to work together as a single giant mirror.

The work performed on the telescope optics resulted in a NASA tech spinoff for diagnosing eye conditions and accurate mapping of the eye.  This spinoff supports research in cataracts, keratoconus (an eye condition that causes reduced vision), and eye movement – and improvements in the LASIK procedure.

Read more about the tech spinoff HERE. 

5. Sunshield and Sunshield Coating

Webb’s primary science comes from infrared light, which is essentially heat energy. To detect the extremely faint heat signals of astronomical objects that are incredibly far away, the telescope itself has to be very cold and stable. This means we not only have to protect Webb from external sources of light and heat (like the Sun and the Earth), but we also have to make all the telescope elements very cold so they don’t emit their own heat energy that could swamp the sensitive instruments. The temperature also must be kept constant so that materials aren’t shrinking and expanding, which would throw off the precise alignment of the optics.

Each of the five layers of the sunshield is incredibly thin. Despite the thin layers, they will keep the cold side of the telescope at around -400°F (-240°C), while the Sun-facing side will be 185°F (85°C). This means you could actually freeze nitrogen on the cold side (not just liquify it), and almost boil water on the hot side. The sunshield gives the telescope the equivalent protection of a sunscreen with SPF 1 million!

Read more about Webb’s incredible sunshield HERE. 

Learn more about the Webb Space Telescope and other complex technologies that have been created for the first time by visiting THIS page.

For the latest updates and news on the Webb Space Telescope, follow the mission on Twitter, Facebook and Instagram.

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Nine Notable Facts About the NACA

The National Advisory Committee for Aeronautics (NACA) reached a major milestone in 2015.

On March 3, the agency that in 1958 would dissolve and reform as NASA celebrated its centennial.

NASA Langley, established in 1917 as the Langley Memorial Aeronautical Laboratory, was the NACA's first field center.

During the March 24 talk, Tom Crouch, senior curator of aeronautics; John Anderson, curator of aerodynamics; and Roger Launius, associate director for collections and curatorial affairs discussed the formation of the NACA, the technological breakthroughs it generated, and the evolution of its research and development model.

Here are nine of the more interesting things they shared:

1. Charles Doolittle Walcott, a self-trained scientist and the man whose efforts led to the formation of the NACA, was best known not as an aeronautics expert, but as a paleontologist. "Throughout his long career," Crouch said, "he was really one of the most effective spokesmen for science and technology in the federal government."

2. Walcott was a good friend of aviation pioneer and Wright brothers rival Samuel Pierpont Langley, who was devastated in 1903 when his Aerodrome flying machine twice failed to take flight over the Potomoc River. Langley died in 1906. "One of Charles Doolittle Walcott's aims in life was to resurrect and honor the memory of his old friend Samuel Pierpont Langley," Crouch said — so much so that he once suggested naming all airplanes Langleys. Eventually, Walcott named the Langley Memorial Aeronautical Laboratory after his friend.

3. Prior to World War I, aeronautics was not a high priority for the U.S. government. On a list of the aeronautics appropriations for 14 countries in the period from 1908 to 1913, the United States was dead last with $435,000. That put the U.S. behind Brazil, Chile, Bulgaria, Spain and Greece. Topping the list: Germany, with $28 million.

4. In the late 1920s, Fred Weick, a Langley engineer, developed what became known as the NACA cowling, a type of fairing or cover used to reduce drag on aircraft engines. The cowling also improved engine cooling. In 1929, Weick won the Collier Trophy, U.S. aviation's more prestigious award, for this innovation.

5. By the 1930s, the world had entered a golden era of aeronautics — largely due to the NACA. "The NACA was aeronautical engineering," said Anderson. And some of the most important aeronautical innovations were taking place right here at Langley Research Center. It was during the 1930s that Langley aerodynamicist Eastman Jacobs developed a systematic way of designing an airfoil. That systematic design became known as the NACA airfoil, and aircraft makers worldwide began using it.

In 1934, during a high-speed wind tunnel test at Langley, a researcher named John Stack captured the first ever photograph of a shockwave on an airfoil. Credits: NASA

6. Aeronautics researchers in the 1930s were struggling to determine the cause of a peculiar phenomenon — as an object approached the speed of sound, drag greatly increased and lift drastically reduced. In 1934, a young Langley researcher named John Stack figured out why by photographing a high-speed wind tunnel test of an airfoil. The photo captured the culprit — a shockwave. It was the first time a shockwave had ever been photographed on an airfoil. "This was a dramatic intellectual contribution of the NACA that a lot of people don't really appreciate," said Anderson.

7. The woman who developed the format and style guide for the NACA's technical reports was a physicist from North Dakota named Pearl Young. She came to Langley in 1922, the first professional woman employed at the center, and was appointed Langley's first Chief Technical Editor in 1929. "The technical memorandums … became the model worldwide for how to increase knowledge and make it available to the broadest base of people that can use it," said Launius.

8. The NACA used to host an annual Aircraft Engineering Research Conference at Langley. The conferences were "a who's who of anybody involved in aeronautics in the United States," said Launius. "This interchange of information, of ideas, of concerns, becomes the critical component to fueling the research processes that led to some of the great breakthroughs of the early period before World War II." Among the notable attendees at the 1934 conference were Orville Wright, Charles Lindbergh and Howard Hughes.

A photo taken in Langley's Full Scale Tunnel during the 1934 Aircraft Engineering Research Conference at Langley. Orville Wright, Charles Lindbergh and Howard Hughes were in attendance. Credits: NASA

9. Following World War II, according to Launius, the NACA began to change its "model ever so slightly," making its first forays into public-private partnerships. Perhaps the earliest example of these partnerships was the Bell X-1, a joint project between the NACA, the U.S. Air Force and Bell Aircraft Company. The Bell X-1 became the first manned aircraft to break the sound barrier.

Nebula Images: http://nebulaimages.com/

Astronomy articles: http://astronomyisawesome.com/

Orion AA-2 Crew Module Painted for Flight

The Orion crew module for the Ascent Abort Test 2 (AA-2) was transported from NASA's Langley Research Center in Hampton, Virginia, to the Joint Base Langley-Eustis Friday, Jan. 26, for a fresh coat of paint before final testing and shipment to NASA’s Johnson Space Center in Houston. Specific flight test markings are being painted on the crew module to allow for attitude and trajectory data collection during launch. Next, it will be tested to determine the module's mass and weight, and also its center of gravity or balance, and then delivered to Johnson for integration and additional testing.

The crew module to be used for the test, fabricated at Langley, is a simplified representation designed to match the outer shape and approximate mass distribution of the Orion crew module that astronauts will fly in. During the test, planned for April 2019, the launch abort system will be activated during challenging ascent conditions at NASA's Kennedy Space Center in Florida.

Image credit: NASA/David C. Bowman

Congratulations to SpaceX for successfully launching the Falcon Heavy Rocket 🚀

Image Credits: SpaceX; Brady Kenniston/NASAspaceflight.com

Eagle Nebula

via reddit