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  • richardmitnick 5:46 pm on February 12, 2019 Permalink | Reply
    Tags: , , , , Earth's Radiation Belts, JHUAPL, ,   

    From NASA Goddard Space Flight Center: “NASA’s Van Allen Probes Begin Final Phase of Exploration in Earth’s Radiation Belts” 

    NASA Goddard Banner
    From NASA Goddard Space Flight Center

    Feb. 12, 2019

    Geoff Brown
    Johns Hopkins University Applied Physics Lab

    Media contact: Karen C. Fox
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Two tough, resilient, NASA spacecraft have been orbiting Earth for the past six and a half years, flying repeatedly through a hazardous zone of charged particles around our planet called the Van Allen radiation belts. The twin Van Allen Probes, launched in August 2012, have confirmed scientific theories and revealed new structures and processes at work in these dynamic regions. Now, they’re starting a new and final phase in their exploration.

    Van Allen Radiation belts from ESA INTEGRAL

    Van Allen Belts NASA GSFC

    NASA Van Allen Probes

    On Feb. 12, 2019, one of the twin Van Allen Probes begins a series of orbit descent maneuvers to bring its lowest point of orbit, called perigee, just under 190 miles closer to Earth. This will bring the perigee from about 375 miles to about 190 miles — a change that will position the spacecraft for an eventual re-entry into Earth’s atmosphere about 15 years down the line.

    “In order for the Van Allen Probes to have a controlled re-entry within a reasonable amount of time, we need to lower the perigee,” said Nelli Mosavi, project manager for the Van Allen Probes at the Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Maryland. “At the new altitude, aerodynamic drag will bring down the satellites and eventually burn them up in the upper atmosphere. Our mission is to obtain great science data, and also to ensure that we prevent more space debris so the next generations have the opportunity to explore the space as well.”

    The other of the two Van Allen Probes will follow suit in March, also commanded by the mission operations team at APL, which designed and built the satellites.

    1
    The twin Van Allen Probes have spent more than six years orbiting through Earth’s radiation belts. Orbit changes in early 2019 will ensure that the spacecraft eventually de-orbit and disintegrate in Earth’s atmosphere. Credits: NASA Goddard’s Scientific Visualization Studio

    The Van Allen Probes spend most of their orbit within Earth’s radiation belts: doughnut-shaped bands of energized particles — protons and electrons — trapped in Earth’s magnetic field. These fast-moving particles create radiation that can interfere with satellite electronics and could even pose a threat to astronauts who pass through them on interplanetary journeys. The shape, size and intensity of the radiation belts changes in response to solar activity, which makes predicting their state difficult.

    Originally designated as a two-year mission — based on predictions that no spacecraft could operate much longer than that in the harsh radiation belts — these rugged spacecraft have operated without incident since 2012, and continue to enable groundbreaking discoveries about the Van Allen Belts.


    Credits: NASA’s Goddard Space Flight Center

    2
    After performing de-orbit maneuvers in February and March 2019, the Van Allen Probes’ highly elliptical orbits will gradually tighten over the next 15-25 years as the spacecraft experience atmospheric drag at perigee, the point in their orbits closest to Earth. This atmospheric drag will pull them into a circular orbit as early as 2034, at which point the spacecraft will begin to enter Earth’s atmosphere and safely disintegrate. Credits: Johns Hopkins APL

    “The Van Allen Probes mission has done a tremendous job in characterizing the radiation belts and providing us with the comprehensive information needed to deduce what is going on in them,” said David Sibeck, mission scientist for the Van Allen Probes at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The very survival of these spacecraft and all their instruments, virtually unscathed, after all these years is an accomplishment and a lesson learned on how to design spacecraft.”

    Each spacecraft will be moved to a new, lower perigee of about 190 miles above Earth through a series of five two-hour engine burns. Because the Van Allen Probes spin while in orbit, the dates of these burns had to be chosen carefully. The needed geometry happens just once or twice per year: for spacecraft B, that period falls Feb. 12-22 of this year, and for spacecraft A, it’s March 11-22.

    The engine burns will each use about 4.4 pounds of propellant, leaving the spacecraft with enough fuel to keep their solar panels pointed at the Sun for about one more year.

    “We’ll continue to operate and obtain new science in our new orbit until we are out of fuel, at which point we won’t be able to point our solar panels at the Sun to power the spacecraft systems,” said Mosavi.

    During their last year or so of life, the Van Allen Probes will continue to gather data on Earth’s dynamic radiation belts. And their new, lower passes through Earth’s atmosphere will also provide new insight into how oxygen in Earth’s upper atmosphere can degrade satellite instruments — information that could help engineers design more resilient satellite instruments in the future.

    “The spacecraft and instruments have given us incredible insight into spacecraft operations in a high-radiation environment,” said Mosavi. “Everyone on the mission feels a real sense of pride and accomplishment in the work we’ve done and the science we’ve provided to the world — even as we begin the de-orbiting maneuvers.”

    Read more about what the Van Allen Probes have accomplished since 2012.

    For more on the Van Allen Probes: nasa.gov/vanallenprobes

    See the full article here.


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


    NASA/Goddard Campus

     
  • richardmitnick 6:00 pm on October 27, 2018 Permalink | Reply
    Tags: JHUAPL, , , ,   

    From Spaceflight Insider: “New Horizons team previews Ultima Thule flyby” 

    1

    From Spaceflight Insider

    October 27th, 2018
    Laurel Kornfeld

    1
    An artist’s illustration of New Horizons flying by the Kuiper Belt Object Ultima Thule. Image Credit NASA / JPL / JHUAPL

    In an Oct. 24 online press conference broadcast from the American Astronomical Society (AAS) Division for Planetary Sciences (DPS) 50th Annual Meeting in Knoxville, Tennessee, four members of NASA’s New Horizons team presented a preview of the spacecraft’s Jan. 1, 2019, flyby of Kuiper Belt Object (KBO) Ultima Thule, now just 10 weeks away.

    The presenting speakers included principal investigator Alan Stern of the Southwest Research Institute (SwRI), science team collaborator Carey Lisse of the Johns Hopkins University Applied Physics Laboratory (JHUAPL), project scientist Hal Weaver, also of JHUAPL, and co-investigator Kelsi Singer, also of SwRI.

    1
    Because Ultima Thule is so far away, details cannot yet be resolved and are not expected to be until about a day before the closest approach. Image Credit: NASA/JHUAPL/SwRI

    Stern said this flyby will be more challenging than New Horizons’ Pluto flyby in July 2015 because Ultima Thule is located a billion miles beyond Pluto and much about it remains unknown. Mission scientists are still uncertain about its exact position and the presence of any potentially hazardous rings or moons. The spacecraft is older than it was at Pluto and has less battery power now while light levels are lower at such a great distance from the Sun.

    Additionally, communication between Earth and the spacecraft takes six hours one way, as opposed to four-and-a-half hours to Pluto.

    “New Horizons is going to have the capacity, in the space of one week, the first week of January 2019, to confirm or refute the very models [of solar system formation] presented here at the Division of Planetary Sciences meeting,” Stern said.

    Ultima Thule is estimated to be about 23 miles (37 kilometers) wide, much smaller than Pluto, which has a diameter of 1,477 miles (2,377 kilometers). For this reason, pre-flyby images 10 weeks before closest approach reveal just a dot rather than the increasing level of detail seen on Pluto during the same time frame. Details on the KBO will not be resolved until about one day before closest approach, Stern said.

    In addition to being the most distant object ever explored by a spacecraft, Ultima Thule, which is about ten times as wide and 1,000 times as massive as Comet 67P/Churyumov-Gerasimenko, which was orbited by the Rosetta spacecraft, is set to be the most primitive object studied by a spacecraft.

    ESA/Rosetta spacecraft


    ESA Rosetta Philae Lander

    To preview what the KBO’s surface might look like, Lisse presented images of Comet Wild 2, Saturn’s moon Phoebe, Saturn’s moon Hyperion, and Comet 67P.

    All seven instruments aboard New Horizons will study Ultima Thule. Between now and the flyby, mission scientists will prepare by monitoring changes in the KBO’s brightness to determine its size, shape, and rotation speed, search for moons and other potential hazards to the spacecraft, and refine navigation if hazards are found, Weaver explained.

    Diversion from the optimal closest approach of 2,170 miles (3,500 kilometers) can be made as late as Dec. 16 if hazards are discovered. An alternate, safer approach would bring New Horizons within 6,200 miles (10,000 kilometers) of Ultima Thule. Image resolution will be better than that obtained at Pluto because of the closer approach.

    2
    Possible Shapes of Ultima Thule. Image Credit: NASA/JHUAPL/SwRI.

    Singer outlined the mission’s goals as mapping the KBO’s geology and morphology and mapping its color and composition. Specifically, scientists will look for craters and grooves and various ices, including ammonia, carbon monoxide, methane, and water ice. They will also determine whether Ultima Thule is a binary or contact binary object or a double-lobed object like Comet 67P.

    Because KBOs are composed of pristine materials left over from the formation of the solar system, studying Ultima Thule’s ices will give scientists insight into the materials from which Earth and the solar system’s other planets were built.

    Mission scientists also hope to find answers as to why Ultima Thule, a very dark object, is slightly brighter than expected. They do not expect to find active geology or an atmosphere on such a small object.

    “This will be our first ground truth, our first close look at what makes these [Kuiper Belt] objects dark and red,” Singer said.

    Kuiper Belt. Minor Planet Center

    As done at Pluto, New Horizons will return a final image of Ultima Thule just before closest approach, then remain out of contact with Earth, instead focusing on data collection. Between 10 a.m. and 10:30 a.m. EST (15:00-15:30 GMT) Jan. 1, a signal from the probe is expected to arrive, confirming it survived the flyby.

    New Horizons will continue to study the KBO and its environment for a short time after closest approach. Return of the data collected will continue through late 2020.

    3
    Ultima Thule Timeline Overview. Image Credit: NASA/JHUAPL/SwRI

    Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science.

    HPHS Owls

    She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program.

    Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.

    [Sorry folks, I could not resist the references to my home town and my university]

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    SpaceFlight Insiderreports on events taking place within the aerospace industry. With our team of writers and photographers, we provide an “insider’s” view of all aspects of space exploration efforts. We go so far as to take their questions directly to those officials within NASA and other space-related organizations. At SpaceFlight Insider, the “insider” is not anyone on our team, but our readers.

    Our team has decades of experience covering the space program and we are focused on providing you with the absolute latest on all things space. SpaceFlight Insider is comprised of individuals located in the United States, Europe, South America and Canada. Most of them are volunteers, hard-working space enthusiasts who freely give their time to share the thrill of space exploration with the world.

     
  • richardmitnick 10:03 am on August 7, 2018 Permalink | Reply
    Tags: , , , , , JHUAPL, ,   

    From JHU HUB: “Can the Parker Solar Probe take the heat?” 

    Johns Hopkins

    From JHU HUB

    8.6.18
    By Tracy Vogel

    1
    NASA JHUAPL Parker Solar Probe approaches the sun.

    Researchers at the Applied Physics Lab develop a shield strong enough to protect the spacecraft’s sensitive instruments during its mission to “touch” the sun.

    The star of the show is a dark gray block, about the size of a textbook, and several inches thick. As an audience of reporters watches, an engineer runs a flaming blowtorch over the block until its face heats to a red glow.

    “You want to take a touch of the back surface?” she invites a NASA T-shirt-clad volunteer.

    The volunteer reaches tentatively out to the back, first with one finger, and then with her whole hand.

    “How does it feel?”

    “Lukewarm,” the volunteer responds. “Not even—normal.”


    Video: NASA Goddard

    The demonstration, dubbed “Blowtorch vs. Heat Shield” on YouTube, represents the culmination of years of research, trial and error, and painstaking analysis by engineers at the Johns Hopkins University Applied Physics Laboratory to solve what they call the “thermal problem” of the Parker Solar Probe, a spacecraft that will travel within 4 million miles of the surface of the sun.

    The “thermal problem” is a gentle way of referring to the complications of performing this record-breaking dive directly into our star’s outer atmosphere, or corona. While the Parker Solar Probe orbits the star and records data with its onboard instruments, a thermal protection system, or TPS, will shield the spacecraft from the heat. Combined with a water-powered cooling system, the TPS will keep the majority of the spacecraft’s instruments at about 85 degrees Fahrenheit—a nice summer day—while the TPS itself endures a temperature of 2500 degrees Fahrenheit.

    Without the TPS, there’s no probe.

    “This was the technology that enabled us to do this mission—to enable it to fly,” says Elisabeth Abel, TPS thermal lead. “It’s going to be incredibly exciting to see something you put a lot of energy and hard work into, to see it actually fly. It’s going to be a big day.”

    The “thermal problem” is a gentle way of referring to the complications of performing this record-breaking dive directly into our star’s outer atmosphere, or corona. While the Parker Solar Probe orbits the star and records data with its onboard instruments, a thermal protection system, or TPS, will shield the spacecraft from the heat. Combined with a water-powered cooling system, the TPS will keep the majority of the spacecraft’s instruments at about 85 degrees Fahrenheit—a nice summer day—while the TPS itself endures a temperature of 2500 degrees Fahrenheit.

    The Parker Solar Probe is expected to launch from Kennedy Space Center in Cape Canaveral, Florida, this month—its launch window opens Saturday and runs through Aug. 23. During its seven-year mission, it’ll explore some of the sun’s greatest mysteries: Why is the solar wind a breeze closer to the sun but supersonic torrent farther away? Why is the corona itself millions of degrees hotter than the surface of the sun? What are the mechanisms behind the astoundingly fast-moving solar energetic particles that can interfere with spacecraft, disrupt communications on Earth, and endanger astronauts?

    The launch will conclude 60 years of planning and effort, and more than a decade spent creating the heat shield that deflects the worst of the sun’s energy.

    The front and back faces of the heat shield are made of sheets of carbon-carbon, a lightweight material with superior mechanical properties especially suited for high temperatures. At less than a tenth of an inch thick, the two carbon-carbon sheets are thin enough to bend, even if they were laid on top of each other. Between them is about 4.5 inches of carbon foam, typically used in the medical industry for bone replacement. This sandwich design stiffens everything up—like corrugated cardboard—while allowing the 8-foot heat shield to weigh in at only about 160 pounds.

    The foam also performs the heat shield’s most essential structural functions. Carbon itself conducts heat, but carbon foam is 97 percent air. In addition to cutting the weight of the spacecraft to help it get into orbit, the foam structure means there’s just not that much material for heat to travel through. The heat shield will be 2500 degrees Fahrenheit on the side facing the sun, but only 600 degrees Fahrenheit at the back.

    The foam wasn’t easy to test. It’s extremely fragile, and there was another problem.

    “When you get it hot, it can combust,” Abel says.

    Combustion isn’t an issue in a vacuum (like in space), but leftover air in test chambers would cause the foam to char. So the engineers built their own vacuum chamber at Oak Ridge National Laboratory, where a high-temperature plasma-arc lamp facility could heat the material to the incredible temperatures the heat shield would endure.

    3
    Image credit: Greg Stanley / Office of Communications

    But all of the carbon foam’s impressive heat-dispersing properties weren’t enough to keep the spacecraft at its required temperature. Because there’s no air in space to provide cooling, the only way for material to expel heat is to scatter light and eject heat in the form of photons. For that, another layer of protection was necessary: a white coating that would reflect heat and light.

    For that, APL turned to the Advanced Technology Laboratory in Johns Hopkins University’s Whiting School of Engineering, where a fortunate coincidence had led to the assembly of a heat shield–coating dream team: experts in high-temperature ceramics, chemistry, and plasma spray coatings.

    After extensive engineering and testing, the team settled on a coating based on bright white aluminum oxide. But that coating could react with the carbon of the heat shield in high temperatures and turn gray, so the engineers added a layer of tungsten, thinner than a strand of hair, between the heat shield and the coating to stop the two from interacting. They added nanoscale dopants to make the coating whiter and to inhibit the expansion of aluminum oxide grains when exposed to heat.

    Then the engineers had to determine how best to create and apply the coating.

    “The whole thing was struggling to find a ceramic coating that both reflects light and emits the heat,” says Dennis Nagle, principal research engineer at the Center for Systems Science and Engineering.

    Typically when working with enamel, Nagle says, a hard, nonporous coating is preferred—one that’ll crack when hit with a hammer. But under the temperatures faced by the Parker Solar Probe, a smooth coating would shatter like a window hit with a rock. Instead the goal was a uniformly porous coating that would withstand extreme environments. When cracks start in a porous coating, they’ll stop when they hit a pore. The coating was made of several rough, grainy layers—enough that one set of ceramic grains would reflect light that another layer misses.

    “I always tell people it works because it’s a lousy coating,” jokes Nagle. “If you want to make a good coating, it’ll fail.”

    After the Parker Solar Probe launches, it will spin repeatedly around Venus in a gradually narrowing orbit that will take it closer and closer to the sun. Scientists are eagerly awaiting the flood of new data from the probe’s instruments, but those who helped make the heat shield a reality say the thrill will be in seeing that final dip into the sun’s atmosphere, seven times closer than any previous spacecraft, the car-sized probe and its precious cargo defended from the sun’s might by their work.

    But seven years is a long time to wait for a final test of success, so the launch will have to do for now.

    “This was highly challenging,” says Dajie Zhang, a senior staff scientist in APL’s Research and Exploratory Development Department who worked on the TPS coating. “It makes me feel much better coming into work every day. The solar probe’s success showed me I can do it, and our team can do it.”

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    About the Hub

    We’ve been doing some thinking — quite a bit, actually — about all the things that go on at Johns Hopkins. Discovering the glue that holds the universe together, for example. Or unraveling the mysteries of Alzheimer’s disease. Or studying butterflies in flight to fine-tune the construction of aerial surveillance robots. Heady stuff, and a lot of it.

    In fact, Johns Hopkins does so much, in so many places, that it’s hard to wrap your brain around it all. It’s too big, too disparate, too far-flung.

    We created the Hub to be the news center for all this diverse, decentralized activity, a place where you can see what’s new, what’s important, what Johns Hopkins is up to that’s worth sharing. It’s where smart people (like you) can learn about all the smart stuff going on here.

    At the Hub, you might read about cutting-edge cancer research or deep-trench diving vehicles or bionic arms. About the psychology of hoarders or the delicate work of restoring ancient manuscripts or the mad motor-skills brilliance of a guy who can solve a Rubik’s Cube in under eight seconds.

    There’s no telling what you’ll find here because there’s no way of knowing what Johns Hopkins will do next. But when it happens, this is where you’ll find it.

    Johns Hopkins Campus

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
  • richardmitnick 8:34 am on March 15, 2018 Permalink | Reply
    Tags: , , , , , JHUAPL, , , ,   

    From JHUAPL via EarthSky: “Pluto craft’s next target is Ultima Thule” 

    Johns Hopkins
    Johns Hopkins University

    Johns Hopkins Applied Physics Lab bloc
    JHU Applied Physics Lab

    EarthSky

    March 14, 2018
    Deborah Byrd

    NASA/New Horizons spacecraft

    passed Pluto in 2015.

    With public input, the mission team has nicknamed the spacecraft’s next target – on the fringes of our solar system – Ultima Thule.

    3
    This image shows New Horizons’ current position along its full planned trajectory toward MU69, now nicknamed Ultima Thule. The green segment of the line shows where the spacecraft has traveled since launch; the red indicates the spacecraft’s future path. Image via Johns Hopkins University Applied Physics Laboratory.

    Some 115,000 people from around the world recently suggested some 34,000 possible nicknames for the distant object 2014 MU69, the next target of the New Horizons spacecraft, whose historic sweep past Pluto took place in July 2015. The New Horizons mission team announced on March 13, 2018, it has selected the name Ultima Thule – pronounced ultima thoo-lee – for New Horizon’s next target, a Kuiper Belt object officially named 2014 MU69. New Horizons will sweep closest to Ultima Thule on January 1, 2019. The mission team describes the object as:

    “… the most primitive world ever observed by spacecraft, in the farthest planetary encounter in history….”

    In a statement, the team explained their reasons for their choice:

    “Thule was a mythical, far-northern island in medieval literature and cartography. Ultima Thule means “beyond Thule” – beyond the borders of the known world – symbolizing the exploration of the distant Kuiper Belt and Kuiper Belt objects that New Horizons is performing, something never before done.”

    Alan Stern of Southwest Research Institute in Boulder, Colorado, is New Horizons’ principal investigator. He said:

    “MU69 is humanity’s next Ultima Thule. Our spacecraft is heading beyond the limits of the known worlds, to what will be this mission’s next achievement. Since this will be the farthest exploration of any object in space in history, I like to call our flyby target Ultima, for short, symbolizing this ultimate exploration by NASA and our team.”

    6
    Artist’s conception of NASA’s New Horizons spacecraft encountering 2014 MU69 – now nicknamed Ultima Thule – on January 1, 2019. This object orbits a billion miles (1.6 billion km) beyond Pluto. Evidence gathered from Earth suggests it might be a binary (double) or multiple object. Image via NASA/ Johns Hopkins University Applied Physics Laboratory/ SwRI/ Steve Gribben.

    NASA and the New Horizons team launched the nickname campaign in early November. Hosted by the SETI Institute of Mountain View, California, and led by Mark Showalter, an institute fellow and member of the New Horizons science team, the online contest sought nominations from the public and stipulated that a nickname would be chosen from among the top vote-getters.

    SETI Institute


    The campaign wrapped up on December 6, after a five-day extension to accommodate more voting. Of the 34,000 names suggested, 37 reached the ballot for voting and were evaluated for popularity. This included eight names suggested by the New Horizons team and 29 nominated by the public.

    The team then narrowed its selection to the 29 publicly nominated names and gave preference to names near the top of the polls. Names suggested included Abeona, Pharos, Pangu, Rubicon, Olympus, Pinnacle and Tiramisu. Final tallies in the naming contest posted here.

    About 40 members of the public nominated the name Ultima Thule. This name was one of the highest vote-getters among all name nominees. Showalter said:

    “We are grateful to those who proposed such an interesting and inspirational nickname. They deserve credit for capturing the true spirit of exploration that New Horizons embodies.”

    After the flyby, NASA and the New Horizons team say they’ll choose a formal name to submit to the International Astronomical Union, based in part on whether MU69 is found to be a single body, a binary pair, or perhaps a system of multiple objects.

    Learn more about New Horizons, NASA’s mission to Pluto and the Kuiper Belt, at http://www.nasa.gov/newhorizons and http://pluto.jhuapl.edu.

    7
    New Horizons mission team members during the 2015 Pluto encounter. Expect more excitement to come when New Horizons encounters Ultima Thule on January 1, 2019!

    Bottom line: With public input, the New Horizons mission team has given the nickname Ultima Thule to the spacecraft’s next target, Kuiper Belt Object 2014 MU69.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    Johns Hopkins Applied Physics Lab Campus

    Founded on March 10, 1942—just three months after the United States entered World War II—APL was created as part of a federal government effort to mobilize scientific resources to address wartime challenges.

    APL was assigned the task of finding a more effective way for ships to defend themselves against enemy air attacks. The Laboratory designed, built, and tested a radar proximity fuze (known as the VT fuze) that significantly increased the effectiveness of anti-aircraft shells in the Pacific—and, later, ground artillery during the invasion of Europe. The product of the Laboratory’s intense development effort was later judged to be, along with the atomic bomb and radar, one of the three most valuable technology developments of the war.

    On the basis of that successful collaboration, the government, The Johns Hopkins University, and APL made a commitment to continue their strategic relationship. The Laboratory rapidly became a major contributor to advances in guided missiles and submarine technologies. Today, more than seven decades later, the Laboratory’s numerous and diverse achievements continue to strengthen our nation.

    APL continues to relentlessly pursue the mission it has followed since its first day: to make critical contributions to critical challenges for our nation.

    Johns Hopkins Campus

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
  • richardmitnick 12:23 pm on July 5, 2017 Permalink | Reply
    Tags: , Asteroids and their impact, , , , , JHUAPL,   

    From Hopkins APL: “NASA plans to test asteroid deflection technique designed to prevent Earth impact” 

    Johns Hopkins
    Johns Hopkins University

    Johns Hopkins Applied Physics Lab bloc
    Applied Physics Lab

    7.3.17
    Geoff Brown

    JHU’s Applied Physics Lab will manage DART mission, which is moving from concept development to preliminary design phase.

    NASA is moving forward with a plan to develop a refrigerator-sized spacecraft capable of deflecting asteroids and preventing them from colliding with Earth.

    The Double Asteroid Redirection Test, or DART, is being designed and would be built and managed by scientists at the Johns Hopkins Applied Physics Laboratory. NASA approved a move from concept development to the preliminary design phase on June 23.

    1
    NASA/ESA DART
    Artist concept of NASA’s DART spacecraft, part of NASA’s first mission to demonstrate an asteroid deflection technique for planetary defense. Image credit: NASA/JHUAPL

    DART would use what is known as a kinetic impactor technique—striking the asteroid to shift its orbit. The impact would change the speed of a threatening asteroid by a small fraction of its total velocity, but by doing so well before the predicted impact, this small nudge will add up over time to a big shift of the asteroid’s path away from Earth.

    A test with a small, nonthreatening asteroid is planned for 2024.

    “DART is a critical step in demonstrating we can protect our planet from a future asteroid impact,” said Andy Cheng, who is co-leading the DART investigation at APL along with Andy Rivkin. “Since we don’t know that much about their internal structure or composition, we need to perform this experiment on a real asteroid. With DART, we can show how to protect Earth from an asteroid strike with a kinetic impactor by knocking the hazardous object into a different flight path that would not threaten the planet.”

    Small asteroids hit Earth almost daily, breaking up harmlessly in the upper atmosphere. Objects large enough to do damage at the surface are much rarer.

    The target for DART’s first test is an asteroid that will have a distant approach to Earth in October 2022, and then again in 2024. The asteroid is called Didymos—Greek for “twin”—because it’s an asteroid binary system that consists of two bodies: Didymos A, about one-half mile in size; and a smaller asteroid orbiting it called Didymos B, about 530 feet in size. DART would impact only the smaller of the two bodies, Didymos B.

    The Didymos system has been closely studied since 2003. The primary body is a rocky S-type object, with composition similar to that of many asteroids. The composition of its small companion, Didymos B, is unknown, but the size is typical of asteroids that could potentially create regional effects should they impact Earth.

    After launch, DART would fly to Didymos and use an APL-developed onboard autonomous targeting system to aim itself at Didymos B. Then the spacecraft would strike the smaller body at a speed about nine times faster than a bullet, approximately 3.7 miles per second. Earth-based observatories would be able to see the impact and the resulting change in the orbit of Didymos B around Didymos A, allowing scientists to better determine the capabilities of kinetic impact as an asteroid mitigation strategy.

    Objects larger than 0.6 miles in diameter—large enough to cause global effects—have been the focus of NASA’s ground-based search for potentially hazardous objects with orbits that bring them near the Earth. About 93 percent of these sized objects have already been found, NASA says.

    DART would test technologies to deflect objects in the intermediate size range—large enough to do regional damage yet small enough that there are many more that have not been observed and could someday hit Earth. NASA-funded telescopes and other assets continue to search for these objects, track their orbits, and determine if they are a threat.

    To assess and formulate capabilities to address these potential threats, NASA in 2016 established its Planetary Defense Coordination Office, which is responsible for finding, tracking, and characterizing potentially hazardous asteroids and comets coming near Earth; issuing warnings about possible impacts; and assisting plans and coordination of U.S. government response to an actual impact threat.

    ESA AIM Asteroid Impact Mission


    ESA/AIM will work in concert with DART.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    Johns Hopkins Applied Physics Lab Campus

    Founded on March 10, 1942—just three months after the United States entered World War II—APL was created as part of a federal government effort to mobilize scientific resources to address wartime challenges.

    APL was assigned the task of finding a more effective way for ships to defend themselves against enemy air attacks. The Laboratory designed, built, and tested a radar proximity fuze (known as the VT fuze) that significantly increased the effectiveness of anti-aircraft shells in the Pacific—and, later, ground artillery during the invasion of Europe. The product of the Laboratory’s intense development effort was later judged to be, along with the atomic bomb and radar, one of the three most valuable technology developments of the war.

    On the basis of that successful collaboration, the government, The Johns Hopkins University, and APL made a commitment to continue their strategic relationship. The Laboratory rapidly became a major contributor to advances in guided missiles and submarine technologies. Today, more than seven decades later, the Laboratory’s numerous and diverse achievements continue to strengthen our nation.

    APL continues to relentlessly pursue the mission it has followed since its first day: to make critical contributions to critical challenges for our nation.

    Johns Hopkins Campus

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
  • richardmitnick 1:26 pm on June 26, 2017 Permalink | Reply
    Tags: , , , , , JHUAPL,   

    From Hopkins HUB: “As the APL-built solar probe begins its historic encounter with the sun, revolutionary technologies will power and cool the craft” 

    Johns Hopkins
    Johns Hopkins University

    June 23, 2017
    Geoffrey Brown

    1
    The solar panels are shown here on this artist rendering of Parker Solar Probe; they are the black squares with gray rectangles on the center of the spacecraft.
    Image credit: NASA/JHUAPL

    As NASA’s Parker Solar Probe spacecraft begins its first historic encounter with the sun’s corona in late 2018—flying closer to our star than any other mission in history—a revolutionary cooling system will keep its solar arrays at peak performance, even in extremely hostile conditions.

    Every instrument and system on board Parker Solar Probe (with the exception of four antennas and a special particle detector) will be hidden from the sun behind a breakthrough thermal protection system, or TPS—an eight-foot-diameter shield that the spacecraft uses to defend itself against the intense heat and energy of our star.

    Every system will be protected, that is, except for the two solar arrays that power the spacecraft. When the spacecraft is closest to the sun, the solar arrays will be receiving 25 times the solar energy they would while orbiting Earth, and the temperature on the TPS will reach more than 2,500 degrees Fahrenheit. The cooling system will keep the arrays at a nominal temperature of 320°F (160°C) or below.

    “Our solar arrays are going to operate in an extreme environment that other missions have never operated in before,” said Mary Kae Lockwood, the spacecraft system engineer for Parker Solar Probe at the Johns Hopkins Applied Physics Lab.

    New innovations to survive the inferno

    The very outermost edges of the solar arrays are bent upward, and when the spacecraft is closest to the sun, these small slivers of array will be extended beyond the protection of the TPS in order to produce enough power for the spacecraft’s systems.

    3
    The solar array cooling system for the Parker Solar Probe spacecraft is shown undergoing thermal testing at NASA Goddard Space Flight Center in Greenbelt, Maryland, in late February. Image credit: NASA/JHUAPL .

    The incredible heat of our star would damage conventional spacecraft arrays. So, like many other technological advances created especially for this mission, a first-of-its-kind actively cooled solar array system was developed by APL, in partnership with United Technologies Aerospace Systems, which manufactured the cooling system, and SolAero Technologies, which produces the solar arrays.

    “This is all new,” Lockwood said of the innovations related to the actively cooled solar array system. “NASA funded a program for Parker Solar Probe that included technology development of the solar arrays and their cooling system. We worked closely with our partners at UTAS and SolAero to develop these new capabilities, and we came up with a very effective system.”


    Video: JHU Applied Physics Laboratory

    The Parker Solar Probe cooling system has several components: a heated accumulator tank that will hold the water during launch (“If water was in the system, it would freeze,” Lockwood said); two-speed pumps; and four radiators made of titanium tubes and sporting aluminum fins just two hundredths of an inch thick. As with all power on the spacecraft, the cooling system is powered by the solar arrays—the very arrays it needs to keep cool to ensure its operation. At nominal operating capacity, the system provides 6,000 watts of cooling capacity—enough to cool an average-sized living room.

    Somewhat surprisingly, the coolant used is nothing more than regular pressurized water—approximately five liters, deionized to remove minerals that could contaminate or harm the system. Analysis showed that during the mission, the coolant would need to operate between 50°F and 257°F—and few liquids can handle those ranges like water. “Part of the NASA technology demonstration funding was used by APL and our partners at UTAS to survey a variety of coolants,” said Lockwood. “But for the temperature range we required, and for the mass constraints, water was the solution.” The water will be pressurized, which will raise its boiling point above 257°F.

    The solar arrays feature their own technical innovations. “We learned a lot about solar array performance from the [APL-built] MESSENGER spacecraft, which was the first to study Mercury,” said Lockwood. “In particular, we learned how to design a panel that would mitigate degradation from ultraviolet light.”

    The cover glass on top of the photovoltaic cells is standard, but the way the heat is transferred from the cells into the substrate of the panel, the platen, is unique. A special ceramic carrier was created and soldered to the bottom of each cell, and then attached to the platen with a specially chosen thermally conductive adhesive to allow the best thermal conduction into the system while providing the needed electrical insulation.

    From ice to fire: Launch challenges

    While the extraordinary heat of the sun will be the spacecraft’s most intense challenge, the minutes immediately following launch are actually one of the spacecraft’s most critical early performance sequences.

    When Parker Solar Probe launches on board a ULA Delta IV Heavy rocket from Cape Canaveral Air Force Station in Florida in summer 2018, the cooling system will undergo wide temperature swings. “There’s a lot to do to make sure the water doesn’t freeze,” said Lockwood.

    First, temperatures of the solar arrays and cooling system radiators will drop from that in the fairing (about 60°F) to temperatures ranging from –85°F to –220°F before they can be warmed by the sun. The pre-heated coolant tank will keep the water from freezing; the specially designed radiators—designed to reject heat and intense temperatures at the sun—will also survive this bitter cold, thanks to a new bonding process and design innovations.

    Less than 60 minutes later, the spacecraft will separate from the launch vehicle and begin the post-separation sequence. It will rotate itself to point at the sun; the solar arrays will release from their launch locks; the arrays will rotate to point to the sun; a latch valve will open to release the warm water into two of the four radiators and the solar arrays; the pump will turn on; the spacecraft will rotate back to a nominal pointing orientation, warming up the two coldest and unactivated radiators; and power from the cooled solar arrays will begin recharging the battery.

    In another first, this complex and critical series of tasks will be completed autonomously by the spacecraft, without any input from mission control.

    The water for the two unactivated radiators will remain in the storage tank for the first 40 days of flight; after that, the final two radiators will be activated.

    “One of the biggest challenges in testing this is those transitions from very cold to very hot in a short period of time,” Lockwood said. “But those tests, and other tests to show how the system works when under a fully heated TPS, correlated quite well to our models.”

    Thanks to testing and modeling, the team studied data and increased the thermal blanketing on the first two radiators to be activated, in order to balance maximizing their capacity at the end of the mission, and further reduce the risk of water freezing early in the mission.

    Keeping cool, autonomously

    When Parker Solar Probe is hurtling past the sun at some 450,000 miles an hour, it will be 90 million miles from mission controllers on Earth—too far for the team to “drive” the spacecraft. This means that adjustments to how the spacecraft is protecting itself with the TPS need to be handled by Parker Solar Probe’s onboard guidance and control systems. These systems use new and effective autonomous software to allow the spacecraft to instantly alter its pointing to maximize protection from the sun. This autonomous capability is critical to the operation of the spacecraft’s solar arrays, which must be constantly adjusted for optimal angle as Parker Solar Probe hurtles through the sun’s harsh, superheated corona.

    “During solar encounters, very small changes in the wing angle of the solar array can vastly change cooling capacity needed.” Lockwood said that a one degree change in the array angle of one wing would require 35 percent more cooling capacity.

    The constant challenge is to make sure the spacecraft and the arrays are staying cool.

    “There’s no way to make these adjustments from the ground, which means it has to guide itself,” Lockwood said. “APL developed a variety of systems—including wing angle control, guidance and control, electrical power system, avionics, fault management, autonomy and flight software—that are critical parts working with the solar array cooling system.”

    Added Lockwood: “This spacecraft probably is one of the most autonomous systems ever flown.”

    That autonomy, along with the new cooling system and pioneering solar array upgrades, will be crucial to ensuring that Parker Solar Probe can perform the never-before-possible science investigations at the sun that will answer questions scientists have had about our star and its corona. More details about the mission’s objectives are available online.

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    Stem Education Coalition

    Johns Hopkins Campus

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
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