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  • richardmitnick 10:18 pm on February 15, 2018 Permalink | Reply
    Tags: , , , , NASA Goddard, NASA Space Network, NASA TDRS   

    From Goddard: “Last NASA Communications Satellite of its Kind Joins Fleet” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Feb. 15, 2018
    Ashley Hume
    ashley.hume@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    NASA TDRS Tracking and Data Relay Satellite

    NASA has begun operating the last satellite of its kind in the network that provides communications and tracking services to more than 40 NASA missions, including critical, real-time communication with the International Space Station. Following its August launch and a five-month period of in-orbit testing, the third-generation Tracking and Data Relay Satellite (TDRS), referred to as TDRS-M until this important milestone, was renamed TDRS-13, becoming the tenth operational satellite in the geosynchronous, space-based fleet.

    “With TDRS-13’s successful acceptance into the network, the fleet is fully replenished and set to continue carrying out its important mission through the mid-2020s,” said Badri Younes, NASA’s deputy associate administrator for Space Communications and Navigation at NASA Headquarters in Washington. “Now, we have begun focusing on the next generation of near-Earth communications relay capabilities.”

    The 10 TDRS spacecraft comprise the space-based portion of the Space Network, relaying signals from low-Earth-orbiting missions with nearly 100 percent coverage.

    “The acceptance of this final third-generation TDRS into the Space Network is the result of many years of dedication and hard work by the TDRS team,” said Dave Littmann, the TDRS project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “As a result, critical space communication and tracking services that enable NASA human spaceflight and scientific discovery will continue well into the next decade.”

    ​TDRS-13 launched on Aug. 18, 2017, aboard a United Launch Alliance Atlas V rocket from Cape Canaveral Air Force Station in Florida. Built by Boeing in El Segundo, California, TDRS-13 and its nearly identical third-generation sister spacecraft are performing well. TDRS-K and -L launched in 2013 and 2014, respectively.

    NASA established the TDRS project in 1973, and the first satellite launched 10 years later, providing NASA an exponential increase in data rates and contact time communicating with the space shuttle and other orbiting spacecraft, such as the Hubble Space Telescope. Since then, NASA has continued to expand the TDRS constellation and advance the spacecraft capabilities.

    “NASA looks forward to the future, developing even better ways to meet missions’ communications needs,” said Younes. “We will leverage NASA’s success in optical communications and other innovative technologies, as well as significantly increase our partnership with industry, as we envision a shift to increased reliance on commercial networks for most, if not all, of our communications needs in the near-Earth environment.”

    Goddard is home to the TDRS project, which is responsible for the development and launch of these communication satellites. Boeing, headquartered in Chicago, Illinois, is the private contractor for the third-generation TDRS spacecraft. TDRS is the space element of NASA’s Space Network, providing the critical communication and navigation lifeline for NASA missions. NASA’s Space Communications and Navigation (SCaN) program, part of the Human Exploration and Operations Mission Directorate at the agency’s Headquarters in Washington, is responsible for NASA’s Space Network.
    For more information about NASA’s TDRS satellites, visit:
    https://www.nasa.gov/tdrs

    For more information about SCaN, visit:
    https://www.nasa.gov/SCaN

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    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

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  • richardmitnick 3:52 pm on February 9, 2018 Permalink | Reply
    Tags: A Detailed Timeline of The IMAGE Mission Recovery, , , , , NASA Goddard   

    From Goddard: “A Detailed Timeline of The IMAGE Mission Recovery” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Feb. 8, 2018
    By Miles Hatfield
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    The Imager for Magnetopause-to-Aurora Global Exploration, or IMAGE, spacecraft was re-discovered in January 2018 after more than twelve years of silence. A powerhouse of magnetosphere and aurora research, the IMAGE mission was a key driver of studies of the Sun-Earth connection from its launch on March 25, 2000, until its last contact on Dec. 18, 2005.

    Now a watchful citizen scientist, NASA, and a team of IMAGE scientists and engineers detected and received data from the spacecraft. Here’s how it happened.

    Saturday, Jan. 20

    1:39 AM EST: Amateur astronomer Scott Tilley in Roberts Creek, British Columbia, using his home satellite detection rig, begins his nightly sky scan then goes to bed.

    Sometime in the afternoon – Reviewing the previous night’s data manually – 4 MHz at a time – Tilley detects an unexpected radio frequency signal. Analyzing the specifics of its Doppler Curve – the way the frequency modulates as it crosses the sky, like the siren of a passing ambulance – and comparing it to the orbital elements logged in the space-track catalog, it came back as NASA spacecraft 26113, corresponding to the IMAGE mission.

    Unaware of any details of the mission, Tilley shrugged, logged the finding into his database, and continued looking through his data.

    A few minutes later. Reconsidering his findings — why hadn’t he ever detected the satellite in any previous scans? — Tilley took a closer look. Suddenly a portion of the spectrum just below the data he’d read jumped out. The (relatively weak) signal he’d originally detected had only been a harmonic of the spacecraft’s fundamental frequency, which was much stronger – one of the strongest he’d seen.

    Saturday Evening

    A review of public frequency lists – where other amateur astronomers post their findings – came up empty. No one else had detected this satellite in recent years. After some research, Tilley turned up an article on EO PORTAL about the IMAGE mission. “But they were referring to IMAGE in the past-tense,” Tilley said.

    Tilley eventually found IMAGE’s detailed Failure Report which stated that the spacecraft’s power source had likely been tripped, and that NASA had watched to see if it might be rebooted by an extended eclipse. But a 2007 eclipse came and went while IMAGE remained silent, and the mission was declared over.

    “The realization came over me . . . that what I was observing was the fact that the spacecraft had rebooted,” Tilley remarked. “But who’s going to listen to some guy in his basement with a coil of copper wire on his roof?”

    Sunday, Jan. 21

    01:48 am EST – Tilley publishes his findings in a blog post, then spends the next two days at work.

    Tuesday, Jan. 23

    01:38 am EST – Ruminating on his findings with his wife over dinner (who, according to Tilley, admonished him that “someone who’s smart enough to find a lost satellite surely can find the guy who built the thing”), Tilley gets up from the table to do some more research. He discovers the contact information for Dr. James Burch, the IMAGE principal investigator at the Southwest Research Institute in San Antonio, Texas, and emails him about his findings.

    4:41 am EST – Burch responds. “This is very exciting. I really appreciate your doing this and letting me know about it.”

    Burch shares the news with Richard J. Burley, former ground system manager and mission director for IMAGE at Goddard Space Flight Center in Greenbelt, Maryland. Burley (after reportedly having to “clean all the coffee off of my laptop that I spit on it when I saw Jim Burch’s email…”) jumps to action, contacting NASA’s Space Science Mission Operations Office (SSMO) and Deep Space Network (DSN) to alert them.

    11:44 am EST – With the news of the discovery spreading amongst the hobbyist community, amateur observer Paul Marsh reports to Tilley the first independent observation of a similar satellite signal:

    1
    Credits: Twitter: @uhf_satcom

    :12 pm EST – Burley begins communicating with a team of IMAGE scientists and engineers. His plan is to first determine if the object sending the signal is indeed IMAGE, and if so, whether the Deep Space Network can communicate with it.

    3:31 pm EST – Lisa Rhoads, system engineer and former IMAGE DSN Scheduler at NASA Goddard, recovers the last known Nominal Sequence of Events (NSOE) codes used by IMAGE – essential files used to control the Deep Space Network systems during the execution of pre-pass, pass, and post-pass actions that tell the antennae how to communicate with the spacecraft.

    She also updates Burley on the ways that the Deep Space Network had changed since 2005. Major changes include the decommissioning of several ground stations and antennae that were used to track IMAGE in the past, as well as several significant functionality changes in how the communications work.

    11:02 pm EST – Rhoads begins setting up the software required to communicate with IMAGE, including the NSOE codes.

    Thursday, Jan. 25

    To verify Tilley’s radio frequency observations as well as attempt to directly contact the satellite, NASA team members across the US begin coordinating to verify the downlink signal with a spectrum analyzer and capture a digital spectrum recording.

    Steve Waldher (NASA’s Jet Propulsion Laboratory in Pasadena, California), Jack Lippincott (JPL) and Lisa Rhoads (Goddard) coordinate to recover and read the old NSOE files.

    Leslie Ambrose (Goddard) and the Telecom Networks & Technology Branch at Goddard attempt to use a local Near Earth Network antenna to track the spacecraft. Unable to detect a signal on its first attempt, a review of pointing data and center frequency and adjustments are made and another attempt is planned for the following day.

    Rebecca Besser (Goddard) and Dale Fink (Goddard) create orbit models for IMAGE to determine when recent long-duration eclipses occurred and understand when IMAGE could have been rebooted. They identify an eclipse in mid 2012, which was as long as that of 2007, and another in early 2017, though it was not as long.

    Friday, Jan. 26

    11:54 am EST – Engineers at Goddard acquire the downlink signal and analyze its characteristics. Initial readings are consistent with those expected from the IMAGE spacecraft. Further analysis reveals that the signal strength is oscillating, indicating that the target object may be spinning, as would be expected if the object was, in fact, IMAGE.

    Throughout the day, five antennae located throughout the US—in Greenbelt, Maryland; Laurel, Maryland; Berkeley, California; White Sands, New Mexico; and Wallops Island, Virginia—come online to monitor and track the object. With all five sites producing consistent readings, there is much optimism that it is, in fact, IMAGE.

    Saturday, Jan. 27

    2:59 am EST – Tilley completes a review of his data archive and sends results to Burley, suggesting based on analysis of the Doppler Curve that the spacecraft has been transmitting since at least May 4, 2017.

    3
    Doppler curves matching those of IMAGE are detected on May 4, 2017. Credits: Scott Tilley, AScT

    9:28 am EST – Notifying the team that the five antennae have agreed on basic radio frequency characteristics of the object, Burley sets the next goal: to read data from the spacecraft.

    “Once we successfully capture data, we need the tools to examine the data in order to verify with certainty that it is IMAGE,” Burley writes in an email. “The definitive proof of identity requires reading the data, which will contain IMAGE’s unique [NASA-internal] spacecraft ID number: 166. Until this is done, although the evidence may be strong, we cannot be certain that the spacecraft is in fact IMAGE.”

    The challenge for doing so is primarily technical. “The hardware and operating systems that we used back in the day no longer exist,” Burley explains. “The FEDS/ASIST systems still exist and are in use on other missions, but they have been re-hosted, moved from AIX to Linux, and are about a dozen versions ahead of what we used on IMAGE. I’m certain that we’ll run into some compatibility issues.”

    Burley adds a closing question: “Does anyone happen to have a 4 mm tape cartridge reader that will work on a modern Linux workstation and a 16-year-old data tape and not disintegrate it?”

    3:06 pm EST – Meanwhile, Dr. Cees Bassa, an astronomer at the Netherlands Institute for Radio Astronomy and collaborator with Tilley, reviews his own data and detects the purported IMAGE signal as early as October 2016:

    4
    Timeline of IMAGE’s operational periods and eclipses that could have rebooted it. Credits: Dr. Cees Bassa (ASTRON, the Netherlands)

    Monday, Jan. 29

    Word continues to spread of IMAGE’s potential recovery. Burley and the team continue to re-work the software and locate documentation in preparation for retrieving data from the spacecraft.

    Having overcome the first challenges of knowing the signal signature and where to point the antenna to find it, the hard work begins at the Johns Hopkins University Applied Physics Lab, or APL, in Laurel, Maryland, to track and read data from the spacecraft.

    9:40 am EST – IMAGE track begins and the APL Satellite Communications Facility, or SCF, team starts the process of trying to achieve “frame sync lock” – locking onto the spacecraft’s telemetry signal to allow data to be retrieved. The SCF team, working with an incomplete set of IMAGE spacecraft RF and telemetry parameters, try different combinations for over seven hours without success.

    Tuesday, Jan. 30

    Burley successfully locates a 4 mm tape reader – borrowing a backup from the 1995 Solar and Heliospheric Observatory , or SOHO, mission – and begins attempting to read the 16-year-old tapes. Meanwhile, work continues at APL.

    1:40 pm EST – IMAGE track begins again at the APL Satellite Communications Facility.

    2:15 pm EST (approximate) – After slowly fine-tuning the parameters for APL’s 18-meter antenna (APL-18) to find the right combination, lead station engineer Tony Garcia achieves frame sync lock from the spacecraft.

    2:16 pm EST – Bill Dove, SCF manager and engineer at APL, verifies telemetry data frames are being received and files stored correctly. A quick look at the raw telemetry files show they contain actual spacecraft data.

    3:01 pm EST – Bill Dove sends first telemetry file to NASA personnel.

    3:21 pm EST – Tom Bialas (Goddard) downloads the first data file, and at last reads its ID number: 166, matching the IMAGE spacecraft. Emails quickly circulate amongst the team that there has been definitive confirmation that the spacecraft is IMAGE.

    6:20 pm EST – Engineers at APL start an unattended IMAGE track and continue to capture IMAGE data for a continued 8 ½ hours.

    Wednesday, Jan. 31

    The first data is downloaded and its ID read, but actually accessing and decoding the data it contains requires several more steps – and Burley and the team at Goddard are hard at work deciphering them.

    Thursday, Feb. 1

    12:40 pm EST – The first data files, indicating the state of the spacecraft, are successfully decoded. The team learns that the battery is fully charged at 100%, and its temperature is in line with those in 2005 and historic values.

    3:19 pm EST – Engineers at APL continue to capture IMAGE data. Scientists determine that they are now running on Side A of the Power Distribution Unit (PDU) – a surprise given that it had been thought that the side A was dead after a presumed power failure on Thanksgiving Day in 2004.

    The ultimate cause of the current reboot is still not known, but these findings suggest that a reboot in some form has in fact, occurred.

    But the data indicate an overall healthy spacecraft. Next steps for the IMAGE team are to see if they can do more than just listen to the spacecraft, and talk back to it. As of Feb. 7, efforts are still underway.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    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 2:51 pm on February 6, 2018 Permalink | Reply
    Tags: , , , BurstCube, , , , , , NASA Goddard   

    From Goddard: “NASA Technology to Help Locate Electromagnetic Counterparts of Gravitational Waves” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Feb. 6, 2018
    By Lori Keesey
    NASA’s Goddard Space Flight Center

    1
    Principal Investigator Jeremy Perkins and his co-investigator, Georgia de Nolfo, recently won funding to build a new CubeSat mission, called BurstCube. Respectively, Perkins and de Nolfo hold a crystal, or scintillator, and silicon photomultiplier array technology that will be used to detect and localize gamma-ray bursts for gravitational-wave science. The photomultiplier array shown here specifically was developed for another CubeSat mission called TRYAD, which will investigate gamma-ray bursts in high-altitude lightning clouds.
    Credits: NASA/W. Hrybyk

    A compact detector technology applicable to all types of cross-disciplinary scientific investigations has found a home on a new CubeSat mission designed to find the electromagnetic counterparts of events that generate gravitational waves.

    NASA scientist Georgia de Nolfo and her collaborator, astrophysicist Jeremy Perkins, recently received funding from the agency’s Astrophysics Research and Analysis Program to develop a CubeSat mission called BurstCube. This mission, which will carry the compact sensor technology that de Nolfo developed, will detect and localize gamma-ray bursts caused by the collapse of massive stars and mergers of orbiting neutron stars. It also will detect solar flares and other high-energy transients once it’s deployed into low-Earth orbit in the early 2020s.

    The cataclysmic deaths of massive stars and mergers of neutron stars are of special interest to scientists because they produce gravitational waves — literally, ripples in the fabric of space-time that radiate out in all directions, much like what happens when a stone is thrown into a pond.

    Since the Laser Interferometer Gravitational Wave Observatory, or LIGO, confirmed their existence a couple years ago, LIGO and the European Virgo detectors have detected other events, including the first-ever detection of gravitational waves from the merger of two neutron stars announced in October 2017.

    Less than two seconds after LIGO detected the waves washing over Earth’s space-time, NASA’s Fermi Gamma-ray Space Telescope detected a weak burst of high-energy light — the first burst to be unambiguously connected to a gravitational-wave source.

    These detections have opened a new window on the universe, giving scientists a more complete view of these events that complements knowledge obtained through traditional observational techniques, which rely on detecting electromagnetic radiation — light — in all its forms.

    Complementary Capability

    Perkins and de Nolfo, both scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, see BurstCube as a companion to Fermi in this search for gravitational-wave sources. Though not as capable as the much larger Gamma-ray Burst Monitor, or GBM, on Fermi, BurstCube will increase coverage of the sky. Fermi-GBM observes the entire sky not blocked by the Earth. “But what happens if an event occurs and Fermi is on the other side of Earth, which is blocking its view,” Perkins said. “Fermi won’t see the burst.”

    BurstCube, which is expected to launch around the time additional ground-based LIGO-type observatories begin operations, will assist in detecting these fleeting, hard-to-capture high-energy photons and help determine where they originated. In addition to quickly reporting their locations to the ground so that other telescopes can find the event in other wavelengths and home in on its host galaxy, BurstCube’s other job is to study the sources themselves.

    Miniaturized Technology

    BurstCube will use the same detector technology as Fermi’s GBM; however, with important differences.

    Under the concept de Nolfo has advanced through Goddard’s Internal Research and Development program funding, the team will position four blocks of cesium-iodide crystals, operating as scintillators, in different orientations within the spacecraft. When an incoming gamma ray strikes one of the crystals, it will absorb the energy and luminesce, converting that energy into optical light.

    Four arrays of silicon photomultipliers and their associated read-out devices each sit behind the four crystals. The photomultipliers convert the light into an electrical pulse and then amplify this signal by creating an avalanche of electrons. This multiplying effect makes the detector far more sensitive to this faint and fleeting gamma rays.

    Unlike the photomultipliers on Fermi’s GBM, which are bulky and resemble old-fashioned television tubes, de Nolfo’s devices are made of silicon, a semiconductor material. “Compared with more conventional photomultiplier tubes, silicon photomultipliers significantly reduce mass, volume, power and cost,” Perkins said. “The combination of the crystals and new readout devices makes it possible to consider a compact, low-power instrument that is readily deployable on a CubeSat platform.”

    In another success for Goddard technology, the BurstCube team also has baselined the Dellingr 6U CubeSat bus that a small team of center scientists and engineers developed to show that CubeSat platforms could be more reliable and capable of gathering highly robust scientific data.

    “This is high-demand technology,” de Nolfo said. “There are applications everywhere.”

    For other Goddard technology news, go to https://www.nasa.gov/sites/default/files/atoms/files/winter_2018_final_lowrez.pdf

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    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 11:30 am on January 31, 2018 Permalink | Reply
    Tags: , , , , , IceCube cubesat, NASA Goddard   

    From Goddard: “NASA’s Small Spacecraft Produces First 883-Gigahertz Global Ice-Cloud Map” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 30, 2018
    Lori Keesey
    NASA’s Goddard Space Flight Center

    1
    The bread loaf-sized IceCube was deployed from the International Space Station in May. One month later, it began science operations gathering global data about atmospheric ice clouds in the submillimeter wavelengths. Credits: NASA.

    2
    IceCube Principal Investigator Dong Wu set out to demonstrate a commercial 883-Gigahertz radiometer in space, but ended up getting much more: the world’s first ice-cloud map in that frequency. Here he is pictured holding the instrument. Credits: NASA.

    3
    Relatively small teams from both Goddard and the Wallops Flight Facility built the IceCube mission. The Goddard team included (left photo, back row, from left to right): Dong Wu, Michael Solly, Jared Lucey, Jeffrey Piepmeier, Paul Racette, Derek Hudson; (front row, left to right): Melyane Ortiz-Acosta, Armi Pellerano, Carlos Duran-Aviles, Kevin Horgan, Negar Ehsan, and Mark Wong. Credits: NASA

    A bread loaf-sized satellite has produced the world’s first map of the global distribution of atmospheric ice in the 883-Gigahertz band, an important frequency in the submillimeter wavelength for studying cloud ice and its effect on Earth’s climate.

    IceCube — the diminutive spacecraft that deployed from the International Space Station in May 2017— has demonstrated-in-space a commercial 883-Gigahertz radiometer developed by Virginia Diodes Inc., or VDI, of Charlottesville, Virginia, under a NASA Small Business Innovative Research contract. It is capable of measuring critical atmospheric cloud ice properties at altitudes between 3-9 miles (5 Km-15 Km).

    NASA scientists pioneered the use of submillimeter wavelength bands, which fall between the microwave and infrared on the electromagnetic spectrum, to sense ice clouds. However, until IceCube, these instruments had flown only aboard high-altitude research aircraft. This meant scientists could gather data only in areas over which the aircraft flew.

    “With IceCube, scientists now have a working submillimeter radiometer system in space at a commercial price,” said Dong Wu, a scientist and IceCube principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “More importantly, it provides a global view on Earth’s cloud-ice distribution.”

    Sensing atmospheric cloud ice requires scientists deploy instruments tuned to a broad range of frequency bands. However, it’s particularly important to fly submillimeter sensors. This wavelength fills a significant data gap in the middle and upper troposphere where ice clouds are often too opaque for infrared and visible sensors to penetrate. It also reveals data about the tiniest ice particles that can’t be detected clearly in other microwave bands.

    The Technical Challenge

    IceCube’s map is a first of its kind and bodes well for future space-based observations of global ice clouds using submillimeter-wave technology, said Wu, whose team built the spacecraft using funding from NASA’s Earth Science Technology Office’s (ESTO) In-Space Validation of Earth Science Technologies (InVEST) program and NASA’s Science Mission Directorate CubeSat Initiative. The team’s challenge was making sure the commercial receiver was sensitive enough to detect and measure atmospheric cloud ice using as little power as possible.

    Ultimately, the agency wants to infuse this type of receiver into an ice-cloud imaging radiometer for NASA’s proposed Aerosol-Cloud-Ecosystems, or ACE, mission. Recommended by the National Research Council, ACE would assess on a daily basis the global distribution of ice clouds, which affect the Earth’s emission of infrared energy into space and its reflection and absorption of the Sun’s energy over broad areas. Before IceCube, this value was highly uncertain.

    “It speaks volumes that our scientists are doing science with a mission that primarily was supposed to demonstrate technology,” said Jared Lucey, one of IceCube’s instrument engineers. He was one of only a handful of scientists and engineers at Goddard and NASA’s Wallops Flight Facility in Virginia who developed IceCube in just two years. “We met our mission goals and now everything else is bonus,” he said.

    Multiple Lessons Learned

    In addition to demonstrating submillimeter-wave observations from space, the team gained important insights into how to efficiently develop a CubeSat mission, determining which systems to make redundant and which tests to forgo because of limited funds and a short schedule, said Jaime Esper, IceCube’s mission systems designer and technical project manager at Goddard.

    “It wasn’t an easy task,” said Negar Ehsan, IceCube’s instrument system lead. “It was a low-budget project” that required the team to develop both an engineering test unit and a flight model in a relatively short period of time. In spite of the challenges, the team delivered the VDI-provided instrument on time and budget. “We demonstrated for the first time 883-Gigahertz observations in space and proved that the VDI-provided system works appropriately,” she said. “It was rewarding.”

    The team used commercial off-the-shelf components, including VDI’s radiometer. The components came from multiple commercial providers and didn’t always work together harmoniously, requiring engineering. The team not only integrated the radiometer to the spacecraft, but also built spacecraft ground-support systems and conducted thermal-vacuum, vibration, and antenna testing at Goddard and Wallops.

    “IceCube isn’t perfect,” Wu conceded, referring to noise or slight errors in the radiometer’s data. “However, we can make a scientifically useful measurement. We came away with a lot of lessons learned from this CubeSat project, and next time engineers can build it much more quickly.”

    “This is a different mission model for NASA,” Wu continued. “Our principal goal was to show this small mission could be done. The question was, could we can get useful science and advance space technology with a low-cost CubeSat developed under an effective government-commercial partnership. I believe the answer is yes.”

    Small satellites, including CubeSats, are playing an increasingly larger role in exploration, technology demonstration, scientific research and educational investigations at NASA, including: planetary space exploration; Earth observations; fundamental Earth and space science; and developing precursor science instruments like cutting-edge laser communications, satellite-to-satellite communications and autonomous movement capabilities.

    NASA ESTO supports InVEST missions like IceCube and technologies at NASA centers, industry and academia to develop, refine and demonstrate new methods for observing Earth from space, from information systems to new components and instruments.

    For more Goddard technology news, go to https://www.nasa.gov/sites/default/files/atoms/files/winter_2018_final_lowrez.pdf

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    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 2:43 pm on January 25, 2018 Permalink | Reply
    Tags: , , , , NASA Goddard, NASA Poised to Topple a Planet-Finding Barrier, Ultra-Stable Thermal Vacuum system   

    From Goddard: “NASA Poised to Topple a Planet-Finding Barrier” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 25, 2018
    Lori Keesey
    NASA’s Goddard Space Flight Center

    1
    Goddard optics experts Babak Saif (left) and Lee Feinberg (right), with help from engineer Eli Griff-McMahon an employee of Genesis, have created an Ultra-Stable Thermal Vacuum system that they will use to make picometer-level measurements. Credits: NASA/W. Hrybyk

    NASA optics experts are well on the way to toppling a barrier that has thwarted scientists from achieving a long-held ambition: building an ultra-stable telescope that locates and images dozens of Earth-like planets beyond the solar system and then scrutinizes their atmospheres for signs of life.

    Babak Saif and Lee Feinberg at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, have shown for the first time that they can dynamically detect subatomic- or picometer-sized distortions — changes that are far smaller than an atom — across a five-foot segmented telescope mirror and its support structure. Collaborating with Perry Greenfield at the Space Telescope Science Institute in Baltimore, the team now plans to use a next-generation tool and thermal test chamber to further refine their measurements.

    The measurement feat is good news to scientists studying future missions for finding and characterizing extrasolar Earth-like planets that potentially could support life.

    To find life, these observatories would have to gather and focus enough light to distinguish the planet’s light from that of its much brighter parent star and then be able to dissect that light to discern different atmospheric chemical signatures, such as oxygen and methane. This would require a super-stable observatory whose optical components move or distort no more than 12 picometers, a measurement that is about one-tenth the size of a hydrogen atom.

    To date, NASA has not built an observatory with such demanding stability requirements.

    How Displacements Occur

    Displacements and movement occur when materials used to build telescopes shrink or expand due to wildly fluctuating temperatures, such as those experienced when traveling from Earth to the frigidity of space, or when exposed to fierce launch forces more than six-and-a-half times the force of gravity.

    Scientists say that even nearly imperceptible, atomic-sized movements would affect a future observatory’s ability to gather and focus enough light to image and analyze the planet’s light. Consequently, mission planners must design telescopes to picometer accuracies and then test it at the same level across the entire structure, not just between the telescope’s reflective mirrors. Movement occurring at any particular position might not accurately reflect what’s actually happening in other locations.

    “These future missions will require an incredibly stable observatory,” said Azita Valinia, deputy Astrophysics Projects Division program manager. “This is one of the highest technology tall poles that future observatories of this caliber must overcome. The team’s success has shown that we are steadily whittling away at that particular obstacle.”

    The Initial Test

    To carry out the test, Saif and Feinberg used the High-Speed Interferometer, or HSI — an instrument that the Arizona-based 4D Technology developed to measure nanometer-sized dynamic changes in the James Webb Space Telescope’s optical components — including its 18 mirror segments, mounts, and other supporting structures — during thermal, vibration and other types of environmental testing.

    Like all interferometers, the instrument splits light and then recombines it to measure tiny changes, including motion. The HSI can quickly measure dynamic changes across the mirror and other structural components, giving scientists insights into what is happening all across the telescope, not just in one particular spot.

    Even though the HSI was designed to measure nanometer or molecule-sized distortions — which was the design standard for Webb — the team wanted to see it could use the same instrument, coupled with specially developed algorithms, to detect even smaller changes over the surface of a spare five-foot Webb mirror segment and its support hardware.

    The test proved it could, measuring dynamic movement as small as 25 picometers — about twice the desired target, Saif said.

    Next Steps

    However, Goddard and 4D Technology have designed a new high-speed instrument, called a speckle interferometer, that allows measurements of both reflective and diffuse surfaces at picometer accuracies. 4D Technology has built the instrument and the Goddard team has begun initial characterization of its performance in a new thermal-vacuum test chamber that controls internal temperatures to a frosty 1-millikelvin.

    Saif and Feinberg plan to place test items inside the chamber to see if they can achieve the 12-picometer target accuracy.

    “I think we’ve made a lot of progress. We’re getting there,” Saif said.

    For more Goddard technology news, go to https://www.nasa.gov/sites/default/files/atoms/files/winter_2018_final_lowrez.pdf

    See the full article here.

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    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.


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  • richardmitnick 1:35 pm on January 12, 2018 Permalink | Reply
    Tags: , , , , , NASA Goddard, No Planets Needed: NASA Study Shows Disk Patterns Can Self-Generate   

    From Goddard: “No Planets Needed: NASA Study Shows Disk Patterns Can Self-Generate” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 11, 2018
    Jeanette Kazmierczak
    jeanette.a.kazmierczak@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    When scientists searching for exoplanets — worlds located beyond our solar system — first spotted patterns in disks of dust and gas around young stars, they thought newly formed planets might be the cause. But a recent NASA study cautions that there may be another explanation — one that doesn’t involve planets at all.

    Exoplanet hunters watch stars for a few telltale signs that there might be planets in orbit, like changes in the color and brightness of the starlight. For young stars, which are often surrounded by disks of dust and gas, scientists look for patterns in the debris — such as rings, arcs and spirals — that might be caused by an orbiting world.

    “We’re exploring what we think is the leading alternative contender to the planet hypothesis, which is that the dust and gas in the disk form the patterns when they get hit by ultraviolet light,” said Marc Kuchner, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.


    Astronomers thought patterns spotted in disks around young stars could be planetary signposts. But is there another explanation? A new simulation performed on NASA’s Discover supercomputing cluster shows how the dust and gas in the disk could form those patterns — no planets needed. Credits: NASA’s Goddard Space Flight Center

    Kuchner presented the findings of the new study on Thursday, Jan. 11, at the American Astronomical Society meeting in Washington. A paper describing the results has been submitted to The Astrophysical Journal.

    When high-energy UV starlight hits dust grains, it strips away electrons. Those electrons collide with and heat nearby gas. As the gas warms, its pressure increases and it traps more dust, which in turn heats more gas. The resulting cycle, called the photoelectric instability (PeI), can work in tandem with other forces to create some of the features astronomers have previously associated with planets in debris disks.

    Kuchner and his colleagues designed computer simulations to better understand these effects. The research was led by Alexander Richert, a doctoral student at Penn State in University Park, Pennsylvania, and includes Wladimir Lyra, a professor of astronomy at California State University, Northridge and research associate at NASA’s Jet Propulstion Laboratory in Pasadena, California. The simulations were run on the Discover supercomputing cluster at the NASA Center for Climate Simulation at Goddard.

    3
    NCCS Discover Linux supercomputing cluster

    In 2013, Lyra and Kuchner suggested that PeI could explain the narrow rings seen in some disks. Their model also predicted that some disks would have arcs, or incomplete rings, which were first directly observed in 2016 [Astronomy and Astrophysics].

    “People very often model these systems with planets, but if you want to know what a disk with a planet looks like, you first have to know what a disk looks like without a planet,” Richert said.

    Richert is lead author on the new study, which builds on Lyra and Kuchner’s previous simulations by including an additional new factor: radiation pressure, a force caused by starlight striking dust grains.

    Light exerts a minute physical force on everything it encounters. This radiation pressure propels solar sails and helps direct comet tails so they always point away from the Sun. The same force can push dust into highly eccentric orbits, and even blow some of the smaller grains out of the disk entirely.

    3
    Arcs, rings and spirals appear in the debris disk around the star HD 141569A. The black region in the center is caused by a mask that blocks direct light from the star. This image incorporates observations made in June and August 2015 using the Hubble Space Telescope’s STIS instrument.
    Credits: NASA/Hubble/Konishi et al. 2016

    The researchers modeled how radiation pressure and PeI work together to affect the movement of dust and gas. They also found that the two forces manifest different patterns depending on the physical properties of the dust and gas.

    The 2013 simulations of PeI revealed how dust and gas interact to create rings and arcs, like those observed around the real star HD 141569A. With the inclusion of radiation pressure, the 2017 models show how these two factors can create spirals like those also observed around the same star. While planets can also cause these patterns, the new models show scientists should avoid jumping to conclusions.

    “Carl Sagan used to say extraordinary claims require extraordinary evidence,” Lyra said. “I feel we are sometimes too quick to jump to the idea that the structures we see are caused by planets. That is what I consider an extraordinary claim. We need to rule out everything else before we claim that.”

    Kuchner and his colleagues said they would continue to factor other parameters into their simulations, like turbulence and different types of dust and gas. They also intend to model how these factors might contribute to pattern formation around different types of stars.

    A NASA-funded citizen science project spearheaded by Kuchner, called Disk Detective, aims to discover more stars with debris disks. So far, participants have contributed more than 2.5 million classifications of potential disks. The data has already helped break new ground [Astrophysical Journal Letters]in this research.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

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    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.


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  • richardmitnick 11:14 am on January 11, 2018 Permalink | Reply
    Tags: , , , , NASA Goddard, NASA Team First to Demonstrate X-ray Navigation in Space, , NASA/Sextant   

    From Goddard: “NASA Team First to Demonstrate X-ray Navigation in Space” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 11, 2018
    Lori Keesey
    Clare Skelly
    Goddard Space Flight Center

    1
    This illustration shows the NICER mission at work aboard the International Space Station. Credits: NASA’s Goddard Space Flight Center.

    In a technology first, a team of NASA engineers has demonstrated fully autonomous X-ray navigation in space — a capability that could revolutionize NASA’s ability in the future to pilot robotic spacecraft to the far reaches of the solar system and beyond.

    The demonstration, which the team carried out with an experiment called Station Explorer for X-ray Timing and Navigation Technology, or SEXTANT, showed that millisecond pulsars could be used to accurately determine the location of an object moving at thousands of miles per hour in space — similar to how the Global Positioning System, widely known as GPS, provides positioning, navigation, and timing services to users on Earth with its constellation of 24 operating satellites.

    3
    NASA Sextant.

    2
    NICER’s mirror assemblies concentrate X-rays onto silicon detectors to gather data that probes the interior makeup of neutron stars, including those that appear to flash regularly, called pulsars. Credits: NASA’s Goddard Space Flight Center/Keith Gendreau.

    “This demonstration is a breakthrough for future deep space exploration,” said SEXTANT Project Manager Jason Mitchell, an aerospace technologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “As the first to demonstrate X-ray navigation fully autonomously and in real-time in space, we are now leading the way.”

    This technology provides a new option for deep space navigation that could work in concert with existing spacecraft-based radio and optical systems.

    Although it could take a few years to mature an X-ray navigation system practical for use on deep-space spacecraft, the fact that NASA engineers proved it could be done bodes well for future interplanetary space travel. Such a system provides a new option for spacecraft to autonomously determine their locations outside the currently used Earth-based global navigation networks because pulsars are accessible in virtually every conceivable fight regime, from low-Earth to deepest space.

    Exploiting NICER Telescopes

    The SEXTANT technology demonstration, which NASA’s Space Technology Mission Directorate had funded under its Game Changing Program, took advantage of the 52 X-ray telescopes and silicon-drift detectors that make up NASA’s Neutron-star Interior Composition Explorer, or NICER.

    NASA/NICER

    Since its successful deployment as an external attached payload on the International Space Station in June, it has trained its optics on some of the most unusual objects in the universe.

    “We’re doing very cool science and using the space station as a platform to execute that science, which in turn enables X-ray navigation,” said Goddard’s Keith Gendreau, the principal investigator for NICER, who presented the findings Thursday, Jan. 11, at the American Astronomical Society meeting in Washington. “The technology will help humanity navigate and explore the galaxy.”

    NICER, an observatory about the size of a washing machine, currently is studying neutron stars and their rapidly pulsating cohort, called pulsars. Although these stellar oddities emit radiation across the electromagnetic spectrum, observing in the X-ray band offers the greatest insights into these unusual, incredibly dense celestial objects, which, if compressed any further, would collapse completely into black holes. Just one teaspoonful of neutron star matter would weigh a billion tons on Earth.

    Although NICER is studying all types of neutron stars, the SEXTANT experiment is focused on observations of pulsars. Radiation emanating from their powerful magnetic fields is swept around much like a lighthouse. The narrow beams are seen as flashes of light when they sweep across our line of sight. With these predictable pulsations, pulsars can provide high-precision timing information similar to the atomic-clock signals supplied through the GPS system.

    3
    This animation shows how NICER scans the sky and highlights the mission’s main features. Credits: NASA’s Goddard Space Flight Center

    Veteran’s Day Demonstration

    n the SEXTANT demonstration that occurred over the Veteran’s Day holiday in 2017, the SEXTANT team selected four millisecond pulsar targets — J0218+4232, B1821-24, J0030+0451, and J0437-4715 — and directed NICER to orient itself so it could detect X-rays within their sweeping beams of light. The millisecond pulsars used by SEXTANT are so stable that their pulse arrival times can be predicted to accuracies of microseconds for years into the future.

    During the two-day experiment, the payload generated 78 measurements to get timing data, which the SEXTANT experiment fed into its specially developed onboard algorithms to autonomously stitch together a navigational solution that revealed the location of NICER in its orbit around Earth as a space station payload. The team compared that solution against location data gathered by NICER’s onboard GPS receiver.

    “For the onboard measurements to be meaningful, we needed to develop a model that predicted the arrival times using ground-based observations provided by our collaborators at radio telescopes around the world,” said Paul Ray, a SEXTANT co-investigator with the U. S. Naval Research Laboratory. “The difference between the measurement and the model prediction is what gives us our navigation information.”

    The goal was to demonstrate that the system could locate NICER within a 10-mile radius as the space station sped around Earth at slightly more than 17,500 mph. Within eight hours of starting the experiment on November 9, the system converged on a location within the targeted range of 10 miles and remained well below that threshold for the rest of the experiment, Mitchell said. In fact, “a good portion” of the data showed positions that were accurate to within three miles.

    “This was much faster than the two weeks we allotted for the experiment,” said SEXTANT System Architect Luke Winternitz, who works at Goddard. “We had indications that our system would work, but the weekend experiment finally demonstrated the system’s ability to work autonomously.”

    Although the ubiquitously used GPS system is accurate to within a few feet for Earth-bound users, this level of accuracy is not necessary when navigating to the far reaches of the solar system where distances between objects measure in the millions of miles. “In deep space, we hope to reach accuracies in the hundreds of feet,” Mitchell said.

    Next Steps and the Future

    Now that the team has demonstrated the system, Winternitz said the team will focus on updating and fine-tuning both flight and ground software in preparation for a second experiment later in 2018. The ultimate goal, which may take years to realize, would be to develop detectors and other hardware to make pulsar-based navigation readily available on future spacecraft. To advance the technology for operational use, teams will focus on reducing the size, weight, and power requirements and improving the sensitivity of the instruments. The SEXTANT team now also is discussing the possible application of X-ray navigation to support human spaceflight, Mitchell added.

    If an interplanetary mission to the moons of Jupiter or Saturn were equipped with such a navigational device, for example, it would be able to calculate its location autonomously, for long periods of time without communicating with Earth.

    Mitchell said that GPS is not an option for these far-flung missions because its signal weakens quickly as one travels beyond the GPS satellite network around Earth.

    “This successful demonstration firmly establishes the viability of X-ray pulsar navigation as a new autonomous navigation capability. We have shown that a mature version of this technology could enhance deep-space exploration anywhere within the solar system and beyond,” Mitchell said. “It is an awesome technology first.”

    NICER is an Astrophysics Mission of Opportunity within NASA’s Explorers program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA’s Space Technology Mission Directorate funds the SEXTANT component of the mission through its Game Changing Development Program.

    Related Links:

    NASA’s NICER mission website
    More information on SEXTANT
    Download NICER-SEXTANT multimedia resources

    See the full article here.

    Please help promote STEM in your local schools.

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    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.


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  • richardmitnick 3:05 pm on January 3, 2018 Permalink | Reply
    Tags: , , , , , Magnetospheric Multiscale Mission, NASA Goddard, or MMS   

    From Goddard: “NASA’s Magnetospheric Multiscale Mission Locates Elusive Electron Act” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 3, 2018
    Mara Johnson-Groh
    mara.johnson-groh@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    The space high above Earth may seem empty, but it’s a carnival packed with magnetic field lines and high-energy particles. This region is known as the magnetosphere and, every day, charged particles put on a show as they dart and dive through it.

    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase

    Like tiny tightrope walkers, the high-energy electrons follow the magnetic field lines. Sometimes, such as during an event called magnetic reconnection where the lines explosively collide, the particles are shot off their trajectories, as if they were fired from a cannon.

    Since these acts can’t be seen by the naked eye, NASA uses specially designed instruments to capture the show. The Magnetospheric Multiscale Mission, or MMS, is one such looking glass through which scientists can observe the invisible magnetic forces and pirouetting particles that can impact our technology on Earth. New research uses MMS data to improve understanding of how electrons move through this complex region — information that will help untangle how such particle acrobatics affect Earth.

    NASA/MMS

    NASA MMS satellites in space


    This visualization shows the motion of one electron in the magnetic reconnection region. As the spacecraft approaches the reconnection region, it detects first high-energy particles, then low-energy particles. Credits: NASA’s Goddard Space Flight Center/Tom Bridgman

    Scientists with MMS have been watching the complex shows electrons put on around Earth and have noticed that electrons at the edge of the magnetosphere often move in rocking motions as they are accelerated. Finding these regions where electrons are accelerated is key to understanding one of the mysteries of the magnetosphere: How does the magnetic energy seething through the area get converted to kinetic energy — that is, the energy of particle motion. Such information is important to protect technology on Earth, since particles that have been accelerated to high energies can at their worst cause power grid outages and GPS communications dropouts.

    New research, published in the Journal of Geophysical Research, found a novel way to help locate regions where electrons are accelerated. Until now, scientists looked at low-energy electrons to find these accelerations zones, but a group of scientists lead by Matthew Argall of the University of New Hampshire in Durham has shown it’s possible, and in fact easier, to identify these regions by watching high-energy electrons.

    This research is only possible with the unique design of MMS, which uses four spacecraft flying in a tight tetrahedral formation to give high temporal and spatial resolution measurements of the magnetic reconnection region.

    “We’re able to probe very small scales and this helps us to really pinpoint how energy is being converted through magnetic reconnection,” Argall said.

    The results will make it easier for scientists to identify and study these regions, helping them explore the microphysics of magnetic reconnection and better understand electrons’ effects on Earth.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    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 8:51 am on December 22, 2017 Permalink | Reply
    Tags: , , , , , NASA Goddard, New Study Finds 'Winking' Star May Be Devouring Wrecked Planets, RZ Piscium   

    From Goddard via Manu: “New Study Finds ‘Winking’ Star May Be Devouring Wrecked Planets” 


    Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Dec. 21, 2017

    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    A team of U.S. astronomers studying the star RZ Piscium has found evidence suggesting its strange, unpredictable dimming episodes may be caused by vast orbiting clouds of gas and dust, the remains of one or more destroyed planets.

    1
    RZ Piscium, located in the constellation Pisces, is surrounded by huge dust clouds that appear to be the remains of one or more destroyed planets. Photo: NASA

    “Our observations show there are massive blobs of dust and gas that occasionally block the star’s light and are probably spiraling into it,” said Kristina Punzi, a doctoral student at the Rochester Institute of Technology (RIT) in New York and lead author of a paper describing the findings. “Although there could be other explanations, we suggest this material may have been produced by the break-up of massive orbiting bodies near the star.”


    Zoom into RZ Piscium, a star about 550 light-years away that undergoes erratic dips in brightness. This animation illustrates one possible interpretation of the system, with a giant planet near the star slowly dissolving. Gas and dust intermittently stream away from the planet, and these clouds occasionally eclipse the star as we view it from Earth. Credits: NASA’s Goddard Space Flight Center/CI Lab.

    RZ Piscium is located about 550 light-years away in the constellation Pisces. During its erratic dimming episodes, which can last as long as two days, the star becomes as much as 10 times fainter. It produces far more energy at infrared wavelengths than emitted by stars like our Sun, which indicates the star is surrounded by a disk of warm dust. In fact, about 8 percent of its total luminosity is in the infrared, a level matched by only a few of the thousands of nearby stars studied over the past 40 years. This implies enormous quantities of dust.

    These and other observations led some astronomers to conclude that RZ Piscium is a young Sun-like star surrounded by a dense asteroid belt, where frequent collisions grind the rocks to dust.

    But the evidence was far from clear. An alternative view suggests the star is instead somewhat older than our Sun and just beginning its transition into the red giant stage. A dusty disk from the star’s youth would have dispersed after a few million years, so astronomers needed another source of dust to account for the star’s infrared glow. Because the aging star is growing larger, it would doom any planets in close orbits, and their destruction could provide the necessary dust.

    So which is it, a young star with a debris disk or a planet-smashing stellar senior? According to the research by Punzi and her colleagues, RZ Piscium is a bit of both.

    The team investigated the star using the European Space Agency’s (ESA) XMM-Newton satellite, the Shane 3-meter telescope at Lick Observatory in California and the 10-meter Keck I telescope at W. M. Keck Observatory in Hawaii.

    ESA/XMM Newton X-ray telescope

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)

    UCSC Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)


    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    Young stars are often prodigious X-ray sources. Thanks to 11 hours of XMM-Newton observations, Punzi’s team shows that RZ Piscium is, too. Its total X-ray output is roughly 1,000 times greater than our Sun’s, essentially clinching the case for stellar youth.

    The team’s ground-based observations revealed the star’s surface temperature to be about 9,600 degrees Fahrenheit (5,330 degrees Celsius), only slightly cooler than the Sun’s. They also show the star is enriched in the tell-tale element lithium, which is slowly destroyed by nuclear reactions inside stars.

    “The amount of lithium in a star’s surface declines as it ages, so it serves as a clock that allows us to estimate the elapsed time since a star’s birth,” said co-author Joel Kastner, director of RIT’s Laboratory for Multiwavelength Astrophysics. “Our lithium measurement for RZ Piscium is typical for a star of its surface temperature that is about 30 to 50 million years old.”

    So while the star is young, it’s actually too old to be surrounded by so much gas and dust. “Most Sun-like stars have lost their planet-forming disks within a few million years of their birth,” said team member Ben Zuckerman, an astronomy professor at the University of California, Los Angeles. “The fact that RZ Piscium hosts so much gas and dust after tens of millions of years means it’s probably destroying, rather than building, planets.”

    Ground-based observations also probed the star’s environment, capturing evidence that the dust is accompanied by substantial amounts of gas. Based on the temperature of the dust, around 450 degrees F (230 degrees C), the researchers think most of the debris is orbiting about 30 million miles (50 million kilometers) from the star.

    “While we think the bulk of this debris is about as close to the star as the planet Mercury ever gets to our Sun, the measurements also show variable and rapidly moving emission and absorption from hydrogen-rich gas,” said co-author Carl Melis, an associate research scientist at the University of California, San Diego. “Our measurements provide evidence that material is both falling inward toward the star and also flowing outward.”

    A paper reporting the findings was published Thurs., Dec. 21, in The Astronomical Journal.

    The best explanation that accounts for all of the available data, say the researchers, is that the star is encircled by debris representing the aftermath of a disaster of planetary proportions. It’s possible the star’s tides may be stripping material from a close substellar companion or giant planet, producing intermittent streams of gas and dust, or that the companion is already completely dissolved. Another possibility is that one or more massive gas-rich planets in the system underwent a catastrophic collision in the astronomically recent past.

    ESA’s XMM-Newton observatory was launched in December 1999 from Kourou, French Guiana. NASA funded elements of the XMM-Newton instrument package and provides the NASA Guest Observer Facility at Goddard, which supports use of the observatory by U.S. astronomers.

    See the full Goddard article here.
    See Manu Garcia’s full article here. Look near the top for the language translator.

    Please help promote STEM in your local schools.

    STEM Icon

    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 11:09 am on December 21, 2017 Permalink | Reply
    Tags: , , , , , , Mission to the sun: Special delivery - Parker Solar Probe heads to NASA's Goddard Space Flight Center for environmental testing, NASA Goddard,   

    From JHU HUB- “Mission to the sun: Special delivery – Parker Solar Probe heads to NASA’s Goddard Space Flight Center for environmental testing” 

    Johns Hopkins
    JHU HUB

    12.20.17
    Hub staff report

    Spacecraft designed, built at JHU’s Applied Physics Lab is scheduled for launch in 2018.

    1
    The Parker Solar Probe team at Johns Hopkins APL prepares to lift the heat shield in preparation for shipment to NASA’s Goddard Space Flight Center. Image credit: NASA / Johns Hopkins APL / Ed Whitman.

    How do you prepare to move the first spacecraft to touch the sun? The same way you would move anything else: carefully wrap it, pack it, rent a truck, and perform a nitrogen purge.

    Last month, the Parker Solar Probe spacecraft traveled from the Johns Hopkins Applied Physics Laboratory, where it was designed and built, to NASA’s Goddard Space Flight Center in Greenbelt, Maryland. It’s a short drive, but it took significant preparation.

    2
    NASA’s Parker Solar Probe, shown in protective bagging to prevent contamination, is mounted on a rotating pedestal. Image credit: NASA / Johns Hopkins APL / Ed Whitman

    First, the spacecraft was wrapped in a special protective layer to prevent dust or dirt from reaching the probe. Then it was bolted to a specially designed pedestal that carefully tilted the probe onto its side to fit it inside a shipping container. If kept upright, the probe would have been too tall to pass under highway bridges during transport.

    Once boxed and loaded onto a truck bed, the scientists performed a nitrogen purge, slowly sucking air and moisture out of the container and replacing it with ultra-dry nitrogen with an extremely low dew point. A nitrogen purge is a common practice among military and commercial aerospace projects to prevent corrosive moisture and condensation from reaching sensitive electronics.

    3
    Image credit: NASA / Johns Hopkins APL / Ed Whitman

    The move, accompanied by a state police escort, took place at 4 a.m.—to avoid traffic, of course.

    4
    No, it’s not a still from the movie E.T., it’s members of the testing team preparing the Parker Solar Probe for environmental testing in the Acoustic Test Chamber at NASA’s Goddard Space Flight Center. Image credit: NASA / Johns Hopkins APL / Ed Whitman.

    At Goddard, the Parker Solar Probe has undergone extensive testing and simulations to ensure it’s ready for its historic mission next year (launch is scheduled for between July 31 and Aug. 19).

    It underwent an acoustic test, which subjected the probe to sound forces like those generated during a rocket launch. Goddard’s Acoustic Test Chamber is a 42-foot-tall chamber that uses 6-foot-tall speakers that can reach 150 decibels to simulate the extreme noise of the Delta IV Heavy, the highest-capacity rocket currently in operation and the vehicle that will carry the probe into space.

    The spacecraft’s specially designed Thermal Protection System, or TPS, has also gone through thorough testing. The heat shield, developed by scientists at APL and the Whiting School of Engineering, is made of carbon-carbon composite material to protect the probe from the intense heat of the sun’s atmosphere, which can reach temperatures of almost 2,500 degrees Fahrenheit. As the spacecraft hurtles through the hot solar atmosphere and back out into outer space, the TPS will keep the instruments on the spacecraft at approximately room temperature.

    5
    The probe’s Thermal Protection System is lowered into the Thermal Vacuum Chamber at NASA’s Goddard Space Flight Center in preparation for environmental testing. Image credit: NASA / Johns Hopkins APL / Ed Whitman.

    The heat shield was tested in Goddard’s Thermal Vacuum Chamber, which simulated the harsh conditions that it will endure during the mission.

    During its mission, the Parker Solar Probe will use seven Venus flybys over the course of nearly seven years to gradually shrink its orbit around the sun, coming as close as 3.7 million miles—about eight times closer to the sun than any spacecraft has come before. Upon its closest orbit, the Parker Solar Probe will be traveling at about 450,000 miles per hour. That’s fast enough to get from Philadelphia to Washington, D.C., in one second.

    The solar probe, named for Eugene Parker, the astrophysicist who predicted the existence of the solar wind in 1958, is a “true mission of exploration,” the scientists write on the mission homepage. “Still, as with any great mission of discovery, Parker Solar Probe is likely to generate more questions than it answers.”

    See the full article here .

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    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.

     
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