http___www.index.hr_Black_clanak_nasa-zbog-kvara-odgodila-lansiranje-prvog-satelita-za-mjerenje-co2-u-atmosferi_757563.aspx_1.xml
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WASHINGTON - NASA on Wednesday launched a satellite designed to track carbon dioxide, a leading greenhouse gas that is responsible for global warming. The Orbiting Carbon Observatory-2 took off aboard a Delta 2 rocket at 2:56 am from Vandenberg Air Force Base in California. The successful takeoff was a boon to NASA, after two previous bids to launch Earth science spacecraft -- one for carbon and another for aerosols -- failed due to rocket malfunctions in 2009 and 2011. An attempt to launch the satellite Tuesday was also aborted at the last minute, after engineers discovered a problem with water flow to the launch pad. Tim Dunn, NASA launch director, said the team received "very good news" that the satellite's solar arrays had deployed on schedule and described the mood in mission control as one of "pure joy." "The spacecraft was rock-solid," he said on NASA TV, after live video showed mission control staff hugging and shaking hands. "It all came together tonight." Our #OCO2 carbon-counting mission is in a polar orbit: http://t.co/MS68Grko0U #GIF of spacecraft separation: http://t.co/xxrmcYlaqi — NASA (@NASA) July 2, 2014 Where Carbon Goes The satellite is now a part of the A-Train, a constellation of five other international Earth-observing satellites. The OCO-2 mission lasts two years and aims to provide the most detailed picture to date of natural sources of carbon dioxide -- where it is coming from and where it gets absorbed on the Earth's surface. "The observatory will study how these sources and sinks are distributed around the globe and how they change over time," NASA said. Human activities, like the burning of oil and coal, send nearly 40 billion tons of carbon dioxide into the atmosphere each year, according to the U.S. space agency. About half of that is absorbed back into forests and the oceans. But scientists still know little about where and how the carbon is absorbed, and how to predict the effect that future rises in carbon dioxide will have on the Earth's climate. "For society to better manage carbon dioxide levels in our atmosphere, we need to be able to measure the natural source and sink processes," said David Crisp, OCO-2 science team leader at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. The OCO-2 will take 24 measurements of carbon in the atmosphere every second -- about a million per day -- but clouds are a major obstacle. Its field of view is about one square mile (three square kilometers), so even wispy clouds can obscure its measurements. NASA expects about 100,000 of the satellite's data snapshots from around the world daily will be sufficiently cloud-free to be useful. "This challenging mission is both timely and important," said Michael Freilich, director of the Earth Science Division of NASA's Science Mission Directorate in Washington. OCO-2's data will lay "the foundation for informed policy decisions on how to adapt to and reduce future climate change," he said. - Kerry Sheridan, AFP Copyright Agence France-Presse, 2014
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Foto: Instagram/NASA NASA je danas odgodila lansiranje svog prvog satelita koji će mjeriti razine ugljičnog dioksida (CO2) u atmosferi, plina koji se smatra glavnim krivcem za stvaranje učinka staklenika što dovodi do zagrijavanja planeta. Lansiranje satelita OCO-2 bilo je predviđeno za 11.56 sati po srednjoeuropskom vremenu iz zračne baze Vandenberg u Kaliforniji raketom Delta 2. Odgođeno je u posljednji trenutak zbog "tehničkog problema", a novi termin lansiranja još nije utvrđen. Televizija NASA-e objavila je da će u najboljem slučaju novi pokušaj lansiranja satelita uslijediti u srijedu ujutro. Satelit će biti postavljen u gotovo polarnu orbitu na 705 kilometara visine. Satelit puna naziva Orbiting Carbon Observatory-2 (OCO-2) vrlo je sličan satelitu OCO-1 koji je bio uništen tijekom lansiranja u veljači 2009. OCO-2 treba pružiti cjelovitiju i globalniju sliku emisija CO2, kako onih za koje je odgovoran čovjek tako i prirodnih. Također treba utvrditi učinke oceana i šuma koji apsorbiraju i hvataju taj plin kojega je razina u atmosferi najviša u razdoblju od najmanje 800.000 godina. "Ugljični dioksid u atmosferi igra važnu ulogu u energetskoj ravnoteži našeg planeta i ključan je čimbenik za razumijevanje promjena naše klime", objasnio je Michael Freilich iz znanstvenog odjela Zemlje u NASA-i. Satelit bi trebao uvelike pridonijeti boljem razumijevanju planeta Zemlje, rekao je Freilich. Misija OCO-2 trajat će najmanje dvije godine, a on će biti glavni opservatorij skupine od pet drugih međunarodnih satelita koja će se okretati oko Zemlje svakih 99 minuta. Satelit će uzimati uzorke CO2 i tako pomagati znanstvenicima da bolje prouče promjene klime. U travnju su mjesečne koncentracije ugljičnog dioksida u atmosferi premašile 400 čestica na milijun (ppm) u sjevernoj hemisferi, što je bila najviša razina u najmanje 800.000 godina, ističe NASA. Izgaranje fosilnih goriva (ugljikovodici, prirodni plin i ugljen) i druge ljudske aktivnosti emitiraju gotovo 40 milijarda tona CO2 u atmosferu svake godine. Klimatolozi su zaključili da je rast emisija CO2 posljedica ljudskih aktivnosti, napose izgaranja fosilnih goriva i sječe šuma. Time je izmijenjen prirodni ciklus ugljika na Zemlji te izazvan rast temperature i promjena klime. Sada manje od polovice CO2 emitiranog ljudskim aktivnostima ostaje u atmosferi, navode znanstvenici. Dio tog plina s učinkom staklenika apsorbiraju oceani no još uvijek nisu razjašnjeni svi elementi cirkulacije tog plina. Mjerenja što će ih obaviti satelit OCO-2 kombinirat će se s podacima koje prikupljaju opservacijske postaje na kopnu, zrakoplovi i drugi sateliti.