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Borucki W.J.,NASA | Koch D.G.,NASA | Basri G.,University of California at Berkeley | Batalha N.,San Jose State University | And 66 more authors.
Astrophysical Journal | Year: 2011

On 2011 February 1 the Kepler mission released data for 156,453 stars observed from the beginning of the science observations on 2009 May 2 through September 16. There are 1235 planetary candidates with transit-like signatures detected in this period. These are associated with 997 host stars. Distributions of the characteristics of the planetary candidates are separated into five class sizes: 68 candidates of approximately Earth-size (Rp < 1.25 R⊕), 288 super-Earth-size (1.25 R⊕ ≤ R p < 2 R⊕), 662 Neptune-size (2 R ⊕ ≤ Rp < 6 R⊕), 165 Jupiter-size (6 R⊕ ≤ Rp < 15 R ⊕), and 19 up to twice the size of Jupiter (15 R ⊕ ≤ Rp < 22 R⊕). In the temperature range appropriate for the habitable zone, 54 candidates are found with sizes ranging from Earth-size to larger than that of Jupiter. Six are less than twice the size of the Earth. Over 74% of the planetary candidates are smaller than Neptune. The observed number versus size distribution of planetary candidates increases to a peak at two to three times the Earth-size and then declines inversely proportional to the area of the candidate. Our current best estimates of the intrinsic frequencies of planetary candidates, after correcting for geometric and sensitivity biases, are 5% for Earth-size candidates, 8% for super-Earth-size candidates, 18% for Neptune-size candidates, 2% for Jupiter-size candidates, and 0.1% for very large candidates; a total of 0.34 candidates per star. Multi-candidate, transiting systems are frequent; 17% of the host stars have multi-candidate systems, and 34% of all the candidates are part of multi-candidate systems. © 2011. The American Astronomical Society. All rights reserved.


News Article | November 11, 2015
Site: phys.org

That's a benefit for numerous industries where the clamping force of bolts is critical, including construction, auto assembly, nuclear power, racing, aviation and space. "Any performance application will have a need for this," says Dr. Gang Wang, assistant professor of mechanical and aerospace engineering who is testing the new washer system with Dr. David (Andy) Hissam, a UAH mechanical and aerospace engineering doctoral graduate who works at NASA's Marshall Space Flight Center (MSFC) and is the team lead for the Propulsion Detailed Design Branch (ER34). A bolt's clamping force, called preload, is generated as the bolt stretches during tightening. The two most common methods of applying preload are torque control and turn control. In torque control, a specified torque is placed on the fastener, typically with a torque wrench. In turn control, the nut is turned through a specified angle that stretches the bolt the desired amount. Both methods are only approximations of the true preload exerted because friction plays a major role in the readings obtained. "When you use a torque wrench, you are measuring torque, not the preload. You can be off the bolt's specified preload by plus or minus 35 percent by using a torque wrench as an indicator because of the amount of friction involved, which is very difficult to quantify," says Dr. Hissam. "That means," says Dr. Hissam, indicating a drawing of a flange, "that to get 2,000 pounds of preload on each bolt, a different torque value would have to be applied to each one." The washer the pair is developing uses piezoelectric filaments connected to a handheld device that registers the preload value by reading the electrical output of the filaments. Piezoelectric materials have the capacity generate a voltage when they are subjected to mechanical stress. "When you tighten it up, this directly indicates how much force this washer is experiencing, which is directly related to the bolt's preload," say Dr. Wang. "Instead of a plus or minus 35 percent variance, we are shooting for a closer range, like 5 percent to 10 percent." The two have filed a NASA Disclosure of Invention and New Technology and have received a 2016 MSFC Center Innovation Fund grant to further test and refine the washer. "We are continuing to look for additional sources of funding in order to further develop it," Dr. Wang says. Tests getting underway now will involve determining an appropriate low-cost material in which to embed the piezoelectric filaments, vibration and temperature testing and trials to accumulate the data necessary to provide accurate preload readings. "Two things we are after are accuracy and to keep the costs down," says Dr. Wang. "We want to test so that we can be sure that when a technician tightens a bolt he gets that specific value he is looking for every time." Because a piezoelectric load cell is ceramic and fragile, the tests will also provide information about optimizing washer design to avoid breaking the sensing elements. "You don't want a force directly applied to the piezo matter; you will break it," Dr. Wang says. Since that renders the washer's measuring capability useless, the washer's metallic elements must be designed to carry the majority of the load. "We are also looking at what type of material we should use to surround the piezo material that will protect it best," he says. "That way we can be sure the piezo element will provide an accurate reading and not break." If the elements can be preserved, the washer could be used many times. "There should be no reason," Dr. Hissam says, "that it can't be reused."


News Article | February 21, 2017
Site: www.prnewswire.co.uk

ATX-MS-1467 Reduced the Number and Volume of Brain Lesions With a Very Promising Safety Profile Apitope, the drug discovery and development company focused on treating the underlying cause of autoimmune diseases, announces positive results from the Phase IIa clinical study of its lead product candidate, ATX-MS-1467, for the treatment of patients with multiple sclerosis. The Phase IIa, open-label, one arm study evaluated the effects of ATX-MS-1467 in 19 patients with relapsing multiple sclerosis. The investigational product was administered intradermally (ID) every 2 weeks for 20 weeks. Following a dose titration of 50 and 200 μg in the initial 4 weeks of treatment a dose of 800μg was administered fortnightly for a further of 16 weeks. There were statistically significant reductions in total and new T1 Gadolinium enhancing lesions measured using MRI during treatment as well as a significant reduction in the volume of T1 Gadolinium enhancing lesions. The data also showed a strong trend towards improvement in the Multiple Sclerosis Functional Composite (MSFC) score that is used clinically as an indicator of improvement in disability. There were no treatment related serious adverse events and the adverse event profile was mild. Dr Keith Martin, Chief Executive Officer of Apitope, commented, "We are delighted with these positive results that confirm both clinical findings in our Phase Ib trial as well as preclinical results showing significant decreases in MRI detected lesions and disability in a standard multiple sclerosis model. We will continue to progress the development of ATX-MS-1467 as a treatment for multiple sclerosis and are currently preparing for a Phase IIb placebo controlled study to demonstrate clinical efficacy." Dr Jeremy Chataway, Consultant Neurologist, National Hospital for Neurology and Neurosurgery, London, commenting on the results said, "Having been the Chief Investigator on the previous Phase Ib study, it is pleasing to see these promising confirmatory Phase IIa results where ATX-MS-1467 has shown both an encouraging efficacy and an excellent safety and tolerability profile. While these patients were only treated for 20 weeks, results in a Phase IIb study with a longer treatment period will be interesting." The compound had previously completed a Phase I clinical study in six patients with secondary progressive multiple sclerosis (SPMS) and a second Phase I study in 43 relapsing multiple sclerosis patients, assessing safety and biological parameters. The latest results support the further development of ATX-MS-1467 in multiple sclerosis. Apitope is a European biotech company focused on the discovery and development of disease modifying therapies for abnormal immune responses, including autoimmune diseases such as, multiple sclerosis, Graves' disease, and uveitis; and Factor VIII intolerance. Apitope has a patented discovery platform which enables selection of disease-modifying peptide therapies for the target of interest; and has already generated a pipeline of seven programmes in clinical and preclinical development, of which the lead programme in multiple sclerosis is in Phase II. The discovery engine selects Apitopes™ - Antigen Processing Independent epiTOPES. Apitopes are soluble, synthetic peptides from the human sequence which can selectively suppress abnormal immune responses and reinstate the normal immune balance. Stakeholders in the company include Wales Life Sciences Fund, Vesalius Biocapital, LRM, the Wellcome Trust and the US MS charity, Fast Forward. Apitope's lead product candidate is ATX-MS-1467, a potentially disease-modifying therapy for the treatment of multiple sclerosis, is a novel peptide-based therapeutic identified using Apitope's proprietary technology platform. It consists of four short peptides that are derived from myelin basic protein, a key autoantigen in multiple sclerosis. It is designed to induce immunological tolerance of the body's T cells to key autoantigens thought to be involved in the pathogenesis of multiple sclerosis. For more information on the Company, please visit: www.apitope.com For further information: Apitope Dr Keith Martin, CEO Tel: +44-(0)-1291-63-55-11 keith.martin@apitope.com For media enquiries: Hume Brophy Conor Griffin, Alexia Faure, Alexander Protsenko Tel: +44-(0)-20-7862-6381 apitope@humebrophy.com


Buchhave L.A.,Copenhagen University | Latham D.W.,Harvard - Smithsonian Center for Astrophysics | Carter J.A.,Harvard - Smithsonian Center for Astrophysics | Desert J.-M.,Harvard - Smithsonian Center for Astrophysics | And 45 more authors.
Astrophysical Journal, Supplement Series | Year: 2011

We present the discovery of a hot Jupiter transiting an F star in a close visual (03 sky projected angular separation) binary system. The dilution of the host star's light by the nearly equalmagnitude stellar companion (∼0.5mag fainter) significantly affects the derived planetary parameters, and if left uncorrected, leads to an underestimate of the radius and mass of the planet by 10% and 60%, respectively. Other published exoplanets, which have not been observed with high-resolution imaging, could similarly have unresolved stellar companions and thus have incorrectly derived planetary parameters. Kepler-14b (KOI-98) has a period of P = 6.790 days and, correcting for the dilution, has a mass of Mp = 8.40+0.35 -0.34 M J and a radius of Rp = 1.136+0.073-0.054 R J, yielding a mean density of ρp = 7.1 ± 1.1 g cm-3. © 2011. The American Astronomical Society. All rights reserved.


Borucki W.J.,NASA | Koch D.G.,NASA | Basri G.,University of California at Berkeley | Batalha N.,San Jose State University | And 58 more authors.
Astrophysical Journal | Year: 2011

In the spring of 2009, the Kepler Mission commenced high-precision photometry on nearly 156,000 stars to determine the frequency and characteristics of small exoplanets, conduct a guest observer program, and obtain asteroseismic data on a wide variety of stars. On 2010 June 15, the Kepler Mission released most of the data from the first quarter of observations. At the time of this data release, 705 stars from this first data set have exoplanet candidates with sizes from as small as that of Earth to larger than that of Jupiter. Here we give the identity and characteristics of 305 released stars with planetary candidates. Data for the remaining 400 stars with planetary candidates will be released in 2011 February. More than half the candidates on the released list have radii less than half that of Jupiter. Five candidates are present in and near the habitable zone; two near super-Earth size, and three bracketing the size of Jupiter. The released stars also include five possible multi-planet systems. One of these has two Neptune-size (2.3 and 2.5 Earth radius) candidates with near-resonant periods. © 2011. The American Astronomical Society.


Borucki W.J.,NASA | Koch D.G.,NASA | Batalha N.,San Jose State University | Bryson S.T.,NASA | And 83 more authors.
Astrophysical Journal | Year: 2012

A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626 with a period of 290 days. The characteristics of the host star are well constrained by high-resolution spectroscopy combined with an asteroseismic analysis of the Kepler photometry, leading to an estimated mass and radius of 0.970 0.060 M and 0.979 0.020 R. The depth of 492 10 ppm for the three observed transits yields a radius of 2.38 0.13 Re for the planet. The system passes a battery of tests for false positives, including reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A full BLENDER analysis provides further validation of the planet interpretation by showing that contamination of the target by an eclipsing system would rarely mimic the observed shape of the transits. The final validation of the planet is provided by 16 radial velocities (RVs) obtained with the High Resolution Echelle Spectrometer on Keck I over a one-year span. Although the velocities do not lead to a reliable orbit and mass determination, they are able to constrain the mass to a 3σ upper limit of 124 M ⊕, safely in the regime of planetary masses, thus earning the designation Kepler-22b. The radiative equilibrium temperature is 262 K for a planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is a rocky planet, it is the first confirmed planet with a measured radius to orbit in the habitable zone of any star other than the Sun. © 2012. The American Astronomical Society. All rights reserved.


Arnold Sr. W.R.,Defense Group Inc. | Fitzgerald M.,MSFC | Rosa R.J.,MSFC | Stahl H.P.,NASA
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

The advances in manufacturing techniques for lightweight mirrors, such as EXELSIS deep core low temperature fusion, Corning's continued improvements in the Frit bonding process and the ability to cast large complex designs, combined with water-jet and conventional diamond machining of glasses and ceramics has created the need for more efficient means of generating finite element models of these structures. Traditional methods of assembling 400,000 + element models can take weeks of effort, severely limiting the range of possible optimization variables. This paper will introduce model generation software developed under NASA sponsorship for the design of both terrestrial and space based mirrors. The software deals with any current mirror manufacturing technique, single substrates, multiple arrays of substrates, as well as the ability to merge submodels into a single large model. The modeler generates both mirror and suspension system elements, suspensions can be created either for each individual petal or the whole mirror. A typical model generation of 250,000 nodes and 450,000 elements only takes 3-5 minutes, much of that time being variable input time. The program can create input decks for ANSYS, ABAQUS and NASTRAN. An archive/retrieval system permits creation of complete trade studies, varying cell size, depth, and petal size, suspension geometry with the ability to recall a particular set of parameters and make small or large changes with ease. The input decks created by the modeler are text files which can be modified by any text editor, all the shell thickness parameters and suspension spring rates are accessible and comments in deck identify which groups of elements are associated with these parameters. This again makes optimization easier. With ANSYS decks, the nodes representing support attachments are grouped into components; in ABAQUS these are SETS and in NASTRAN as GRIDPOINT SETS, this make integration of these models into large telescope or satellite models easier. © 2013 Copyright SPIE.


Arnold Sr. W.R.,Defense Group Inc. | Bevan R.M.,MSFC | Stahl H.P.,NASA
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

Advances in mirror fabrication are making very large space based telescopes possible. In many applications, only monolithic mirrors can meet the performance requirements. The existing and near-term planned heavy launch vehicles place a premium on lowest possible mass, and then available payload shroud sizes limit near term designs to 4 meter class mirrors. Practical 8 meter class and beyond designs could encourage planners to include larger shrouds, if it can be proven that such mirrors can be manufactured. These two factors, lower mass and larger mirrors, present the classic optimization problem. There is a practical upper limit to how large of a mirror can be supported by a purely kinematic mount system handling both operational and launch loads. This paper shows how the suspension system and mirror blank need to be designed simultaneously. We will also explore the concepts of auxiliary support systems which act only during launch and disengage on orbit. We will define required characteristics of these systems and show how they can substantially reduce the mirror mass. © 2013 Copyright SPIE.


News Article | November 30, 2016
Site: phys.org

The Fast Neutron Spectrometer (FNS) is now aboard the International Space Station. Neutrons contribute to crew radiation exposure and must be measured to assess exposure levels. The FNS, developed by NASA's Marshall Space Flight Center (MSFC) and Johnson Space Center (JSC), uses a new instrument design that can significantly improve the reliability of identifying neutrons in the mixed radiation field found in deep space. The MSFC principle investigator and team lead is Mark Christl. The NASA JSC project manager is Catherine Mcleod and the technical lead is Eddie Semones at NASA JSC. "Our technique improves upon the well-establish 'capture-gated' method that uses boron-10 loaded plastic scintillators to measure the energy of fast neutrons," says Evgeny Kuznetsov, a research engineer at UAH's Center for Space Plasma and Aeronomic Research (CSPAR), who with CSPAR research scientist John Watts worked on the device. "The central element of FNS is a custom composite scintillator combined with specialized electronics that work together to separate clearly the signals due to neutrons from the signals due to other forms of radiation." The FNS is deployed on the ISS for six months to conduct a technology demonstration to evaluate its performance in a space environment. It will then remain indefinitely to fulfill secondary objectives. "The FNS central detector was manufactured in the lab at NSSTC and comprises a structure of 5,000 regularly spaced neutron sensitive Li6-doped scintillating glass fibers cast in a one-liter plastic scintillator," says Kuznetsov. In combination with specially adjusted parameters of readout electronics, the design allows the detector to measure the neutron spectrum in a mixed radiation environment. "The scintillation light produced in these two scintillators is distinct, and we exploit this difference to better understand the signals generated in response to neutrons," says Watts. "The plastic scintillator responds to the neutron losing all of its energy, and the glass fibers provide positive identification that a neutron was captured. This sequence of signals produces a trigger in the electronics, and the data is recorded for analysis." At UAH, Watts did simulations of the detector performance and simulations of gamma rejection efficiency. Kuznetsov designed front-end electronics boards, which acquire signals from photomultiplier tubes attached at the opposite sides of the central detector. These electronics boards amplify and condition acquired signals to achieve optimal neutron detection efficiency and measurement of the energy of the registered neutrons. Kuznetsov also participated in the manufacturing of the central detector. Data acquired during FNS' flight on the ISS will be used to evaluate the performance of the neutron measurement technique as well as the capability of FNS to operate in the space environment. "This validation is critical to insure FNS can meet the radiation monitoring requirements for the deep space environment during manned exploration missions," says Kuznetsov. "The data collected by FNS will be analyzed and compared to measurements made by other techniques and with calculations of the neutron flux predicted by models of the ISS in the low Earth orbit environment."


News Article | December 21, 2015
Site: phys.org

Additive manufacturing, or 3-D printing, is a key technology for enhancing space vehicle designs and manufacturing and enabling more affordable exploration missions. The technology has the potential to influence spacecraft built for leaving Earth and spaceships and landers for visiting other destinations. Future plans include performing engine tests with liquid oxygen and methane—key propellants for Martian landers since methane and oxygen production might be possible on the Red Planet. "We manufactured and then tested about 75 percent of the parts needed to build a 3-D printed rocket engine," said Elizabeth Robertson, the project manager for the additively manufactured demonstrator engine at NASA's Marshall Space Flight Center in Huntsville, Alabama. "By testing the turbopumps, injectors and valves together, we've shown that it would be possible to build a 3-D printed engine for multiple purposes such as landers, in-space propulsion or rocket engine upper stages." Over the last three years, the Marshall team has been working with various vendors to make 3-D printed parts, such as turbopumps and injectors, and test them individually. To test them together, they connected the parts so that they work the same as they do in a real engine. Only they are not packaged together in a configuration that looks like the typical engine you see on a test stand. "In engineering lingo, this is called a breadboard engine," explained Nick Case, the testing lead for the effort. "What matters is that the parts work the same way as they do in a conventional engine and perform under the extreme temperatures and pressures found inside a rocket engine. The turbopump got its "heartbeat" racing at more than 90,000 revolutions per minute (rpm) and the end result is the flame you see coming out of the thrust chamber to produce over 20,000 pounds of thrust, and an engine like this could produce enough power for an upper stage of a rocket or a Mars lander." Seven tests were performed with the longest tests lasting 10 seconds. During the tests, the 3-D printed demonstrator engine experienced all the extreme environments inside a flight rocket engine where fuel is burned at greater than 6,000 degrees Fahrenheit (3,315 degrees Celsius) to produce thrust. The turbopump delivers the fuel in the form of liquid hydrogen cooled below 400 degrees Fahrenheit (-240 degrees Celsius). These tests were performed with cryogenic liquid hydrogen and liquid oxygen, propellants that are mainstays of spaceship propulsion systems. Even if methane and oxygen prove to be the Mars propellant of choice, the propellant combination of cryogenic liquid hydrogen and oxygen tests the limits of 3-D printed hardware because it produces the most extreme temperatures and exposes parts to cryogenic hydrogen, which can cause embrittlement. In addition to testing with methane, the team plans to add other key components to the demonstrator engine including a cooled combustion chamber and nozzle and a turbopump for liquid oxygen. "These NASA tests drive down the costs and risks associated with using additive manufacturing, which is a relatively new process for making aerospace quality parts," said Robertson. "Vendors who had never worked with NASA learned how to make parts robust enough for rocket engines. What we've learned through this project can now be shared with American companies and our partners." To make each part, a design is entered into a 3-D printer's computer. The printer then builds each part by layering metal powder and fusing it together with a laser – a process known as selective laser melting. The 3-D printed turbopump, one of the more complex parts of the engine, had 45 percent fewer parts than similar pumps made with traditional welding and assembly techniques. The injector had over 200 fewer parts than traditionally manufactured injectors, and it incorporated features that have never been used before because they are only possible with additive manufacturing. Complex parts like valves that normally would take more than a year to manufacture were built by in a few months. This made it possible to get the parts built and assembled on the test stand much sooner than if they had been procured and made with traditional methods. Marshall engineers designed the fuel pump and its components and leveraged the expertise of five suppliers to build the parts using 3-D printing processes. "This new manufacturing process really opened the design space and allowed for part geometries that would be impossible with traditional machining or casting methods," said David Eddleman, one Marshall's propulsion designers. "For the valve designs on this engine, we used more efficient structures in the piece parts that resulted in optimized performance." All data on materials characterization and performance for these parts will be available in NASA's Materials and Processes Technical Information System, called MAPTIS, which is available to approved users. To learn more about MAPTIS or request access, visit: maptis.nasa.gov/ NASA propulsion engineer Nick Case explains how engineers configured engine parts to make and test additively manufactured engine parts as a system. Credit: NASA/MSFC Explore further: NASA performs first J-2X powerpack test of the year

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