Jun 4 2013

From The Space Library

RELEASE: 13-171 - NASA PREPARES FOR LAUNCH OF NEXT SOLAR SATELLITE --WASHINGTON -- NASA's next scientific satellite, which is scheduled for launch June 26, will provide the most detailed look ever at the sun's lower atmosphere or interface region. The Interface Region Imaging Spectrograph (IRIS) mission will observe how solar material moves, gathers energy, and heats up as it travels through this largely unexplored region of the solar atmosphere. The interface region, located between the sun's visible surface and upper atmosphere, is where most of the sun's ultraviolet emission is generated. These emissions impact the near-Earth space environment and Earth's climate. The IRIS spacecraft was designed and built by Lockheed Martin's Advanced Technology Center in Palo Alto, Calif. It will launch aboard an Orbital Sciences Corp. Pegasus XL rocket deployed by the company's L-1011 aircraft from Vandenberg Air Force Base on the central California coast. IRIS data will fill a crucial gap in our understanding of the solar interface region upon joining our fleet of heliophysics spacecraft, said Jeffrey Newmark, NASA's IRIS program scientist in Washington. "For the first time we will have the necessary observations for understanding how energy is delivered to the million-degree outer solar corona and how the base of the solar wind is driven." IRIS carries an ultraviolet telescope that feeds a multi-channel imaging spectrograph. The satellite is the first mission designed to use an ultraviolet telescope to obtain high-resolution images and spectra every few seconds and provide observations of areas as small as 150 miles across the sun. Previous observations suggest there are structures in this region of the solar atmosphere 100 to 150 miles wide, but 100,000 miles long, said Alan Title, IRIS principal investigator at Lockheed Martin. "Imagine giant jets like huge fountains that have a footprint the size of Los Angeles and are long enough and fast enough to circle Earth in 20 seconds. IRIS will provide our first high-resolution views of these structures along with information about their velocity, temperature and density." After launch, IRIS will travel in a polar, sun-synchronous orbit around Earth, crossing nearly directly over the poles in such a way that it moves over the equator at the same local time each day. The spacecraft will orbit at an altitude range of 390 miles to 420 miles. This orbit allows for almost continuous solar observations on IRIS' two-year mission. NASA's Ames Research Center in Moffett Field, Calif., will provide IRIS mission operations and ground data systems. The Norwegian Space Centre in Oslo, Norway, will provide regular downlinks of science data. NASA's Launch Services Program at the agency's Kennedy Space Center is responsible for launch management. IRIS is a NASA Small Explorer Mission, which the agency's Goddard Space Flight Center in Greenbelt, Md., manages for the Science Mission Directorate in Washington. The goal of the Explorers Program is to provide frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. Other IRIS contributors include the Smithsonian Astrophysical Observatory in Cambridge, Mass.; Montana State University in Bozeman, Mont.; Stanford University in Stanford, Calif.; and the University of Oslo in Norway.

RELEASE: C13-027 - NASA AWARDS AIRCRAFT OPERATIONS SUPPORT CONTRACT --EDWARDS, Calif. -- NASA has selected L-3 Vertex Aerospace of Madison, Miss., to support the operations of all aircraft assigned to the agency's Dryden Flight Research Center at Edwards Air Force Base and the Dryden Aircraft Operations Facility in nearby Palmdale, Calif. The cost-plus-award-fee contract takes effect July 1 following a month-long phase-in. It covers a base period of 22 months with two one-year options and one 14-month option. If all options are exercised, the total value will be about $77.1 million and the period of performance will extend to June 30, 2018. Under terms of the contract, L-3 Vertex Aerospace is responsible for maintenance of all aircraft, aircraft engines and related ground support equipment for Dryden's fleet of specialized research and support aircraft. The aircraft range from motor gliders and modified commercial aircraft to former military high-performance and one-of-a-kind research aircraft. Services include organizational, intermediate and limited depot-level aircraft maintenance; aircraft modification; and aircrew and flight line operations support. The contract also supports aircraft operations and maintenance when those aircraft are deployed to locations other than Dryden. Major subcontractors identified by L-3 Vertex Aerospace include Integration Innovation Inc., of Huntsville, Ala., and LOGMET LLC of Austin, Texas.

MEDIA ADVISORY: M13-092 - NASA ANNOUNCES MAJOR AIRBORNE POLLUTION/CLIMATE STUDY JUNE 6 --WASHINGTON -- NASA will host a media teleconference at 1 p.m. EDT, Thursday, June 6, to announce a new airborne science campaign over the southern United States. The campaign will investigate how air pollution and natural emissions affect climate and the atmosphere. The Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys campaign, or SEAC4RS, is NASA's most complex airborne mission of the year. The mission targets summertime emissions from intense forest fires in the U.S. West and natural emissions from forests in the Southeast. Flights begin in August from Houston's Ellington Field and continue through September. The panelists for the teleconference are: -- Brian Toon, SEAC4RS principal investigator, Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder -- Hal Maring, radiation sciences program manager, Earth Science Division, Science Mission Directorate, NASA Headquarters, Washington

RELEASE: 13-172 - NASA'S HUBBLE MAPS 3-D STRUCTURE OF EJECTED MATERIAL AROUND ERUPTING STAR --WASHINGTON -- A flash of light from a stellar outburst has provided a rare look at the 3-D structure of material ejected by an erupting nova. Astronomers used NASA's Hubble Space Telescope to observe the light emitted by the close double-star system T Pyxidis, or T Pyx, a recurring nova, during its latest outburst in April 2011. A nova erupts when a white dwarf, the burned-out core of a sun-like star, has siphoned off enough hydrogen from a companion star to trigger a thermonuclear runaway. As hydrogen builds up on the surface of the white dwarf, it becomes hotter and denser until it detonates like a colossal hydrogen bomb, leading to a 10,000-fold increase in brightness in a little more than one day. Nova explosions are extremely powerful, equal to a blast of one million billion tons of dynamite. T Pyx erupts every 12 to 50 years. Contrary to some predictions, the astronomers were surprised to find the ejecta from earlier outbursts stayed in the vicinity of the star and formed a disk of debris around the nova. The discovery suggests material continues expanding outward along the system's orbital plane, but it does not escape the system. We fully expected this to be a spherical shell, says Arlin Crotts of Columbia University, a member of the research team. "This observation shows it is a disk, and it is populated with fast-moving ejecta from previous outbursts." Team member Stephen Lawrence of Hofstra University in Hempstead, N.Y., will present the results Tuesday at the American Astronomical Society meeting in Indianapolis. Team member Jennifer Sokoloski, also of Columbia University and co-investigator on the project, suggests these data indicate the companion star plays an important role in shaping how material is ejected, presumably along the system's orbital plane, creating the pancake-shaped disk. The disk is tilted about 30 degrees from face-on toward Earth. Using Hubble's Wide Field Camera 3, the team took advantage of the blast of light emitted by the erupting nova to trace the light's path as it lit up the disk and material from previous ejecta. The disk is so vast, about a light-year across, that the nova's light cannot illuminate all of the material at once. Instead, the light sweeps across the material, sequentially illuminating parts of the disk, a phenomenon called a light echo. The light reveals which parts of the disk are nearer to Earth and which sections are farther away. By tracing the light, the team assembled a 3-D map of the structure around the nova. We've all seen how light from fireworks shells during the grand finale will light up the smoke and soot from shells earlier in the show, Lawrence said. "In an analogous way, we're using light from T Pyx's latest outburst and its propagation at the speed of light to dissect its fireworks displays from decades past." Although astronomers have witnessed light propagating through material surrounding other novae, this is the first time the immediate environment around an erupting star has been studied in three dimensions. Astronomers have studied light echoes from other novae, but those phenomena illuminated interstellar material around the stars instead of material ejected from them. The team also used the light echo to refine estimates of the nova's distance from Earth. The new distance is 15,600 light-years from Earth. Previous estimates were between 6,500 and 16,000 light-years. T Pyx is located in the southern constellation Pyxis, or the Mariner's Compass. The team is continuing to analyze the Hubble data to develop an outflow model. T Pyx has a history of outbursts. Besides the 2011 event, other previous known eruptions were seen in 1890, 1902, 1920, 1944, and 1966. Astronomers call erupting stars novae, Latin for "new," because they abruptly appear in the sky. A nova quickly begins to fade in several days or weeks as the hydrogen is exhausted and blown into space. The team also includes Helena Uthas of Columbia University. The team's results will appear online Wednesday, June 5 and will be published in the June 20 issue of the Astrophysical Journal Letters. Sokoloski is the paper's lead author.