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Sonntag, 21. April 2013 - 23:22 Uhr

Raumfahrt - Erfolgreicher Start von Antares in Orbit

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Frams: NASA-TV-LIVE


Tags: Antares Launch 

3164 Views

Sonntag, 21. April 2013 - 22:25 Uhr

Raumfahrt - Antares geht an den Start / 3.Versuch am Sonntag

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2.10.2012

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Both of NASA’s commercial space resupply companies are gearing up for launches this week. SpaceX and Orbital Sciences have contracts with NASA to deliver cargo to the International Space Station over the coming years, though each is at a different stage of the process.
Today, Orbital Sciences is rolling out its Antares rocket for the first time to the launch pad at NASA’s Wallops Island Flight Facility on Virginia’s coast. The company recently received approval to operate on the launch pad from the Mid-Atlantic Regional Spaceport that manages the launch facility. The Antares rocket builds upon Orbital Sciences family of rockets and uses surplus engines from the former Soviet Union that have been modified and converted by Aerojet. The Antares will boost the Cygnus spacecraft to the ISS.
Wallops Island is not as well known as other launch facilities such as Cape Canaveral in Florida, but the facility has been operating since 1945 and more than 16,000 rocket launches have taken place there. Most of the rockets have been much smaller, including countless research rockets designed to gather atmospheric information. The launch pads are next to the ocean, just a few dozen yards from the beach.
Orbital Sciences is a veteran of the space industry and will be using Wallops Island for its upcoming Commercial Orbital Transportation Services test flights as well as ongoing resupply missions once they have received approval from NASA. The company hopes to make its first test flight before the end of the year, and has numerous rocket launches under its belt, including small air-launched rockets as well as larger traditional rockets delivering satellites to orbit.
Further south at Cape Canaveral, SpaceX was busy over the weekend with the static fire test of its Falcon 9 rocket, scheduled to make its first contracted commercial cargo trip to the ISS on Sunday. During the test at Launch Complex 40 in Florida, the Falcon 9 successfully fired its nine Dragon Merlin engines on Saturday. The SpaceX team went through the entire launch process as if it were a normal launch and while firmly locked to the ground, the Falcon 9 engines went to full power for two seconds before being shut down.
The SpaceX team is currently reviewing the data from the static fire, and if everything looks good the company will launch at 8:35 p.m. ET on Sunday. Should something cause a delay, SpaceX has backup launch times on Monday and Tuesday.
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Orbital Sciences Corporation’s Antares rocket rolled out to the launch pad at NASA’s Wallops Flight Facility on the morning of Oct. 1, 2012. Over the next several months, Orbital plans a hot-fire test of the Antares first stage, the maiden flight of an Antares rocket, and a cargo delivery demonstration mission to the International Space Station as part of NASA’s Commercial Orbital Transportation Services. 
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Update: 4.04.2013
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Media Invited to NASA Commercial Partner New Rocket Rollout April 6
 
 
WALLOPS ISLAND, Va. -- News media are invited to cover the scheduled Saturday, April 6, morning rollout of Orbital Sciences Corporation's Antares launch vehicle to the Mid-Atlantic Regional Spaceport's Pad-0A at NASA's Wallops Flight Facility on Wallops Island, Va. 
Orbital is testing the Antares rocket and Cygnus cargo logistics spacecraft under NASA's Commercial Orbital Transportation Services (COTS) program. A demonstration flight of Antares and Cygnus to the International Space Station is planned for later this year. Following the successful completion of the COTS demonstration mission to the space station, Orbital will conduct eight cargo resupply flights to the orbiting laboratory through NASA's Commercial Resupply Services contract. 
The rollout, which is scheduled to begin at about 4:45 a.m. EDT, is in preparation for the launch vehicle's test flight later this month. Pad operations to raise the rocket to a vertical position will begin at about 6 a.m. will take two to three hours to complete. The launch window for Antares' test flight is between April 17 and 19. 
Media representatives interested in covering the Antares rollout and pad operations must contact Rebecca Powell at 757-824-1139 or rebecca.h.powell@nasa.gov by 4 p.m., April 5. A media escort will leave Wallops' main gate at 4:30 a.m. for vehicle rollout. Orbital and NASA representatives will be available for comment. All times are tentative, and reporters should contact Wallops for up-to-date information. 
NASA initiatives like COTS are helping develop a robust U.S. commercial space transportation industry with the goal of achieving safe, reliable and cost-effective transportation to and from the space station and low-Earth orbit. In parallel, NASA's Commercial Crew Program is working with commercial space partners developing capabilities to launch U.S. astronauts from U.S. soil in the next few years. 
Quelle: NASA
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Update: 6.04.2013
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The test flight of the Antares rocket is currently targeted for the afternoon of April 16 - 18 from the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility.
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Update: 7.04.2013
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Antares Test Flight Scheduled for April 17
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WALLOPS ISLAND, Va. -- Orbital Sciences Corp. completed roll-out of the first fully-integrated Antares rocket to the Mid-Atlantic Regional Spaceport Pad-0A at NASA's Wallops Flight Facility on Saturday, April 6. Orbital has confirmed an April 17 target launch date for the rocket test flight with a planned liftoff of 5 p.m. EDT. Orbital is testing the Antares rocket under NASA's Commercial Orbital Transportation Services (COTS) program. NASA initiatives like COTS are helping develop a robust U.S. commercial space transportation industry with the goal of achieving safe, reliable and cost-effective transportation to and from the space station and low-Earth orbit.
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Media Accreditation Open for Antares Test Flight

Media accreditation is open for a test flight of Orbital Sciences Corporation's Antares rocket from the Mid-Atlantic Regional Spaceport's Pad-0A at NASA's Wallops Flight Facility in Virginia. Launch is targeted to occur April 17 at approximately 5 p.m. EDT, the day of launch.

Antares is undergoing testing that will enable the rocket to eventually carry experiments and supplies to the International Space Station aboard a Cygnus cargo spacecraft. This test flight will not launch a Cygnus spacecraft or rendezvous with the space station. A demonstration flight of Cygnus to the orbiting laboratory is planned for later this year.
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Quelle: NASA
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Orbital Rolls Out Antares Rocket to Launch Pad at Wallops Island for Upcoming Test Flight
-- Company Targets April 17 for Inaugural Launch of Americas Newest Medium-Class Space Launch Vehicle --

(Dulles, VA 6 April 2013) Early this morning, Orbital Sciences Corporation (NYSE: ORB) rolled out the first fully integrated Antares rocket from its assembly building at NASAs Wallops Flight Facility (WFF) in eastern Virginia in preparation for its inaugural flight that is scheduled for April 17 at approximately 5:00 p.m. (EDT). This morning, beginning at about 4:30 a.m., the Antares rocket was transported about one mile to the Mid-Atlantic Regional Spaceport (MARS) launch pad complex aboard the Transporter/Erector/Launcher (TEL), a specialized vehicle that also raises the rocket to a vertical position on the launch pad and serves as a support interface between the rocket and the launch complexs systems.

With the completion of the Antares roll out today, we are on a clear path to a launch date of April 17, provided there are no significant weather disruptions or major vehicle check-out delays between now and then, said Mr. Michael Pinkston, Orbitals Antares Program Manager. By later today, the Antares rocket will be in a vertical position and fully integrated with the launch mount on the MARS pad.

The Antares test flight, dubbed the A-ONE mission, is the first of two missions Orbital is scheduled to conduct in 2013 under its Commercial Orbital Transportation Services (COTS) Space Act Agreement with NASA. Following a successful A-ONE launch, Orbital will carry out a full flight demonstration of its new Antares/Cygnus cargo delivery system to the International Space Station (ISS) around mid-year. In addition, the company is also scheduled to launch the first of eight operational cargo resupply missions to the ISS in 2013 under the Commercial Resupply Services (CRS) contract with NASA. All COTS and CRS flights will originate from NASAs WFF, which is geographically well suited for ISS missions and can also accommodate launches of scientific, defense and commercial satellites to other orbits.

The Antares medium-class launch system will provide a major increase in the payload launch capability that Orbital can provide to NASA, the U.S. Air Force and other customers. The Antares rocket will launch spacecraft weighing up to 14,000 lbs. into low-Earth orbit, as well as lighter-weight payloads into higher-energy orbits. Orbitals newest launcher is currently on-ramped to both the NASA Launch Services-2 and the U.S. Air Forces Orbital/Suborbital Program-3 contracts, enabling the two largest U.S. government space launch customers to order Antares for right-size and right-price launch services for medium-class spacecraft.

About Orbital

Orbital develops and manufactures small- and medium-class rockets and space systems for commercial, military and civil government customers. The companys primary products are satellites and launch vehicles, including low-Earth orbit, geosynchronous-Earth orbit and planetary exploration spacecraft for communications, remote sensing, scientific and defense missions; human-rated space systems for Earth-orbit, lunar and other missions; ground- and air-launched rockets that deliver satellites into orbit; and missile defense systems that are used as interceptor and target vehicles. Orbital also provides satellite subsystems and space-related technical services to U.S. Government agencies and laboratories.

Quelle: Orbital

 
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Update: 15.04.2013
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The sun rises over NASA's Wallops Flight Facility, where the first Antares rocket built by Orbital Sciences stands poised to launch on its test flight from Wallops Island on Virginia's Eastern Shore. Liftoff set for 5 pm ET on April 17, 2013.
It's almost show time for a new private rocket on Virginia's Eastern Shore.
A commercially built rocket designed to launch unmanned cargo ships to the International Space Station is counting down toward its first-ever flight test this week from Wallops Island, Va., a small island that is home to NASA's Wallops Flight Facility and a young commercial spaceport. Liftoff for the rocket, called Antares, is currently set for Wednesday, April 17, at 5 p.m. EDT (2100 GMT).
Quelle: NASA
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Orbital Sciences readying for launch date
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Jeffrey MacMillan/JEFFREY MACMILLAN -  Orbital Sciences’ Senior Vice President Frank Culbertson Jr. with a model of his company’s Antares rocket in this photo from August 2012. The company plans a test launch of the Antares rocket this month.
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Update: 17.04.2013
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NASA's commercial partner, Orbital Sciences Corporation of Dulles, Va., is scheduled to launch its first Antares rocket from Mid-Atlantic Regional Spaceport Pad-0A at the agency's Wallops Flight Facility in Virginia on Wednesday, April 17. 
Antares is undergoing testing that will enable the rocket to eventually carry experiments and supplies to the International Space Station aboard a Cygnus cargo spacecraft.
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Depending on where you are along the eastern seaboard of the U.S., you might be able to see the flight of our Antares rocket. The downloadable map below shows the projected degrees above the horizon (how high to look) and the path the rocket will fly so that you might be able to glimpse the Antares test flight. The best chance to see the flight extends from about Cape May, NJ southward through the Outer Banks of North Carolina. Also, if you happen to be in Bermuda, you will likely have a clear view of Antares as it rockets by.
 
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The COTS Demonstration Cygnus spacecraft completed a significant milestone on Tuesday, April 2, when its Pressurized Cargo Module (PCM) was attached to the Service Module (SM), and all mechanical flight connections were attached. The PCM was recently loaded with cargo, and was reoriented from the horizontal to the vertical to facilitate the attachment. The vertically oriented PCM was then lifted and precisely relocated over the SM by Orbital engineers and technicians.
After connecting electrical harnesses, the now completed Cygnus will perform a final set of tests to ensure proper functioning of the combined PCM/SM systems. After completion of the testing, the Cygnus will be prepared for transportation to the fueling facility.
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NASA's commercial partner, Orbital Sciences Corporation of Dulles, Va., is scheduled to launch its first Antares rocket from Mid-Atlantic Regional Spaceport Pad-0A at the agency's Wallops Flight Facility in Virginia today at 5 p.m. EDT.
Antares is undergoing testing that will enable the rocket to eventually carry experiments and supplies to the International Space Station aboard a Cygnus cargo spacecraft.
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Nachfolgend Frams von NASA-TV:
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Start-Abbruch durch abgerissenen Schlauch!
 
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Update: 18.04.2013
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The maiden flight of a powerful new rocket designed to loft space station cargo ships into orbit was called off 12 minutes before liftoff Wednesday from the Mid-Atlantic Regional Spaceport on the Virginia coast when an umbilical attached to the booster's second stage pulled away earlier than planned.
After assessing the problem, Orbital Sciences Corp. managers tentatively rescheduled launch for 5 p.m. EDT (GMT-4) Friday, repairs and weather permitting. Forecasters are predicting high winds and possible thunderstorms in the Wallops Island, Va., area Friday afternoon.
"We are still examining all of the data, but it appears that the issue is fairly straightforward," Frank Culbertson, a former space shuttle commander and Orbital vice president, said in a statement.
"With this being the first launch of the new system from a new launch facility, we have taken prudent steps to ensure a safe and successful outcome. Today, our scrub procedures were exercised and worked as planned. We are looking forward to a successful launch on Friday."
The countdown had proceeded smoothly throughout the day Wednesday with no technical problems of any significance. An initially gloomy weather forecast improved dramatically as the day wore on and the rocket was on track for launch at 5 p.m.
But the unexpected umbilical separation at the T-minus 12-minute mark interrupted the countdown.
"LC, we've had a premature separation of the umbilical on stage two so we're going to have to abort for the day," an engineer said on the countdown audio loop.
"OK, copy that," the launch conductor replied. "This is LC on countdown one, abort, abort, abort. This is LC on countdown one, abort, abort, abort, proceed to abort safing procedures."
The scrub was a disappointment to Orbital Sciences engineers who have spent the past six years designing, assembling and testing the two-stage Antares rocket. But company managers took the delay in stride.
"You learn a little bit from every launch attempt," said John Steinmeyer, an Orbital project manager. "We'll take the lessons learned today and move into another launch attempt as soon as it's safe to do so."
The Antares is the most powerful booster in Orbital's inventory and the largest rocket ever built for launch from the MARS/Wallops complex. NASA is counting on the new rocket to help ensure steady delivery of supplies and components to the International Space Station in the wake of the shuttle's retirement.
For the rocket's initial test flight, a heavily instrumented mockup of the company's Cygnus cargo ship was mounted in a protective nose cone. Assuming the test flight goes well, Orbital plans to launch a real Cygnus atop an Antares in mid June to deliver about a ton of supplies and equipment to the space station.
The test flight and the upcoming Cygnus demonstration mission are part of a $288 million contract with NASA to help develop the new launch system. The first of at least eight operational station resupply flights conducted under a separate $1.9 billion contract with NASA, is targeted for mid September.
An umbilical unexpectedly detached from the second stage of Orbital Sciences' Antares rocket 12 minutes before launch Wednesday, forcing engineers to call off the countdown. (Credit: NASA TV)
Quelle: CBS
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Antares Launch Reschedule
Orbital Sciences Corporation has confirmed the next probable attempt to test launch its Antares rocket from NASA's Wallops Flight Facility on Wallops Island, Va., will be no earlier than Friday, April 19, at 5 p.m. EDT.
NASA Television will begin live coverage of the second launch attempt beginning at 4:30 p.m.
Quelle: NASA
 
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Update: 19.04.2013
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Antares launch delayed to Saturday to avoid bad weather
Running two days late because of a minor last-minute technical glitch, Orbital Sciences managers decided Thursday to delay the maiden flight of the company's new Antares rocket one more day to Saturday because of expected bad weather, company officials said.
The 133-foot-tall Antares rocket, built to boost unmanned space station cargo ships into orbit, now is targeted for liftoff from the Mid-Atlantic Regional Spaceport at NASA's Wallops Island, Va., facility during a three-hour window that opens at 5 p.m. EDT (GMT-4) Saturday. The weather is expected to "improve significantly," according to a company update.
Orbital got within 12 minutes of launch Wednesday only to call off the countdown after engineers spotted a data cable that had pulled loose from the rocket's second stage. Frank Culbertson, an Orbital vice president and Antares mission manager, said the issue was relatively easy to resolve and launch was tentatively rescheduled for Friday.
But forecasters said conditions were expected to deteriorate and with high winds and thick clouds expected, Orbital managers decided Thursday to delay the test flight one more day.
The Antares is the most powerful booster in Orbital's inventory and the largest rocket ever built for launch from the MARS/Wallops complex. NASA is counting on the new rocket to help ensure steady delivery of supplies and components to the International Space Station in the wake of the shuttle's retirement.
For the rocket's initial test flight, a heavily instrumented mockup of the company's Cygnus cargo ship is mounted in a protective nose cone. Assuming the test flight goes well, Orbital plans to launch a real Cygnus atop an Antares in mid June to deliver about a ton of supplies and equipment to the space station.
Quelle:Orbital
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Update: 20.04.2013
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Frams von (hoffentlich erfolgreichen) 2.Start-Versuch werden aktuell heute am Abend erfolgen:
 
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Wegen schlechten Wetter´s den Start um weitere 24 Stunden verschoben.
 
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Update: 21.04.2013
Launch from the Mid-Atlantic Regional Spaceport at NASA's Wallops Island, Va., flight facility was re-targeted for 5:00 p.m. EDT (GMT-4) Sunday. Forecasters predicted a 75 percent chance of acceptable weather.
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Alle guten Dinge sind 3, also sind wir Optimisten das heute Abend der dritte Start-Versuch von Antares gelingt!
LIVE-Frams davon gibt es dann hier: 
 
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Tags: Antares Launch 

3848 Views

Samstag, 20. April 2013 - 23:57 Uhr

UFO-Forschung - CENAP, Prof.Dr.Ulrich Walter und Zivilisationen im All-Teil3

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Im Jahre 2002 konnte man zusammen in HR3 in TV-Maintower ebenfalls die Öffentlichkeit seriöse informieren...

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Im Jahre 2012 traf man sich im Talk bei Servus-TV in Salzburg...

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3148 Views

Samstag, 20. April 2013 - 23:55 Uhr

UFO-Forschung - CENAP, Prof.Dr.Ulrich Walter und Zivilisationen im All-Teil1

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Background zu Astronauten und UFOs gab es schon im Jahre 1999, als Dr.Ulrich Walter (ESA-Astronaut) die Wege von CENAP kreuzte und in seinem Buch "Zivilisationen im All" im Kapitel UFOs auf unsere Statistik sowie Bildmaterialien zurückgriff. Danach traf man sich in den Medien immer mal wieder um die Öffentlichkeit gemeinsam seriös und ohne Alien-Märchen zu informieren. Diese drei Teile zeigen die wahren Einschätzungen eines ESA-Astronauten, die sich auch decken mit dem Wissen welches CENAP sich erarbeitet hat.

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3396 Views

Freitag, 19. April 2013 - 23:51 Uhr

Astronomie - Hubble sieht Pferdekopf-Nebel in Super-Details

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BOUT THIS IMAGE:
Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery over a century ago. The nebula is a favorite target for amateur and professional astronomers.
In this new Hubble Space Telescope view, the nebula appears in a new light, as seen in infrared wavelengths. The nebula, shadowy in optical light, appears transparent and ethereal when seen in the infrared, represented here with visible shades. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that are easily seen in infrared light.
The Horsehead was photographed in celebration of the 23rd anniversary of the launch of Hubble aboard the space shuttle Discovery. Over its two decades of producing ground-breaking science, Hubble has benefited from a slew of upgrades, including the 2009 addition of a new imaging workhorse: the high-resolution Wide Field Camera 3 that was used to take this portrait of the Horsehead.
The backlit wisps along the Horsehead's upper ridge are being illuminated by Sigma Orionis, a young five-star system just off the top of the Hubble image. A harsh ultraviolet glare from one of these bright stars is slowly evaporating the nebula. Along the nebula's top ridge, two fledgling stars peek out from their now-exposed nurseries.
Gas clouds surrounding the Horsehead have already dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being photo-evaporated, and a pillar structure forms. Astronomers estimate that the Horsehead formation has about five million years left before it too disintegrates.
The Horsehead Nebula is part of a much larger complex in the constellation Orion. Known collectively as the Orion Molecular Cloud, it also houses other famous objects such as the Great Orion Nebula (M42), the Flame Nebula, and Barnard's Loop. At about 1,500 light-years away, this complex is one of the nearest and most easily photographed regions in which massive stars are being formed.
Hubble's pairing of infrared sensitivity and unparalleled resolution offers a tantalizing hint of what the upcoming James Webb Space Telescope, set for launch in 2018, will be able to do.
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NASA's Hubble Sees a Horsehead of a Different Color
 
 
WASHINGTON -- Astronomers have used NASA's Hubble Space Telescope to photograph the iconic Horsehead Nebula in a new, infrared light to mark the 23rd anniversary of the famous observatory's launch aboard the space shuttle Discovery on April 24, 1990. 
Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery more than a century ago. The nebula is a favorite target for amateur and professional astronomers. It is shadowy in optical light. It appears transparent and ethereal when seen at infrared wavelengths. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that easily are visible in infrared light. 
Hubble has been producing ground-breaking science for two decades. During that time, it has benefited from a slew of upgrades from space shuttle missions, including the 2009 addition of a new imaging workhorse, the high-resolution Wide Field Camera 3 that took the new portrait of the Horsehead. 
The nebula is part of the Orion Molecular Cloud, located about 1,500 light-years away in the constellation Orion. The cloud also contains other well-known objects such as the Great Orion Nebula (M42), the Flame Nebula, and Barnard's Loop. It is one of the nearest and most easily photographed regions in which massive stars are being formed. 
In the Hubble image, the backlit wisps along the Horsehead's upper ridge are being illuminated by Sigma Orionis, a young five-star system just out of view. Along the nebula's top ridge, two fledgling stars peek out from their now-exposed nurseries. 
Scientists know a harsh ultraviolet glare from one of these bright stars is slowly evaporating the nebula. Gas clouds surrounding the Horsehead already have dissipated, but the tip of the jutting pillar contains a slightly higher density of hydrogen and helium, laced with dust. This casts a shadow that protects material behind it from being stripped away by intense stellar radiation evaporating the hydrogen cloud, and a pillar structure forms. 
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy Inc., in Washington. 
Quelle:NASA

3868 Views

Freitag, 19. April 2013 - 23:10 Uhr

Raumfahrt - Spacewalk von ISS-Crew-35 für Kommunikationstechnologie Upgrades

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Spacewalk Preps and Communications Upgrade on Station

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On the eve of a scheduled six-hour spacewalk, the Expedition 35 crew completed a wide-range of science experiments and wrapped up the installation of a new communication system that will enhance the research capabilities of the International Space Station. 
Commander Chris Hadfield of the Canadian Space Agency and Flight Engineer Tom Marshburn of NASA began their workday by participating in several ongoing human research studies. Both astronauts tested their urine for the Pro K experiment as nutritionists monitor how dietary changes affect the bone loss that occurs during spaceflight. Afterward, Hadfield drew a blood sample from Marshburn who then processed and stored the sample in the Minus Eighty-Degree Laboratory Freezer for ISS, or MELFI, to preserve it until it can be returned to Earth for study. 
Marshburn’s fellow NASA astronaut aboard the station, Flight Engineer Chris Cassidy, began his day downloading sound environment data from acoustic dosimeters worn by crew members earlier this week. Cassidy then deployed the dosimeters at various locations throughout the complex to continue tracking the noise levels that crew members are exposed to. 
After the crew’s daily planning conference with flight control teams around the world, Cassidy spent much of his day setting up and operating the Capillary Flow Experiment. Results from this experiment, which takes a close look at how fluids flow across surfaces with complex geometries in a weightless environment, will improve computer models used to design fluid transfer systems and fuel tanks on future spacecraft. 
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Two members of the Expedition 35 crew will venture outside the International Space Station Friday for a six-hour spacewalk to deploy and retrieve several science experiments and install a new navigational aid.
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Expedition 35 Flight Engineers Pavel Vinogradov (left) and Roman Romanenko will participate in a six-hour spacewalk Friday. Credit: NASA
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The spacewalkers' first task will be to install the Obstanovka experiment on the station's Zvezda service module. Obstanovka will study plasma waves and the effect of space weather on Earth's ionosphere. 
They will retrieve the Biorisk experiment, which studied the effect of microbes on spacecraft structures. If time permits, they also will retrieve one section of the Vinoslivost experiment, which exposed materials samples to space. 
While at the far end of Zvezda, Vinogradov and Romanenko will replace a faulty retro-reflector device, one of a suite of navigational aids that will provide assistance to the European Space Agency's Albert Einstein Automated Transfer Vehicle 4 cargo ship during its final approach for an automated docking to the space station in June. 
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Quelle NASA
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Frams: NASA-TV-LIVE
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Update: 20.04.2013
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Spacewalkers Deploy Plasma Experiment, Install Navigational Aid
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Two members of the Expedition 35 crew wrapped up a 6-hour, 38 minute spacewalk at 4:41 p.m. EDT Friday to deploy and retrieve several science experiments on the exterior of the International Space Station and install a new navigational aid. 
Russian Flight Engineers Pavel Vinogradov and Roman Romanenko opened the hatch to the Pirs airlock and docking compartment to start the spacewalk at 10:03 a.m. 
The spacewalkers' first task was to install the Obstanovka experiment on the station's Zvezda service module. Obstanovka will study plasma waves and the effect of space weather on Earth's ionosphere. 
While at the far end of Zvezda, Vinogradov and Romanenko replaced a faulty retro-reflector device, one of a suite of navigational aids that will provide assistance to the European Space Agency's Albert Einstein Automated Transfer Vehicle 4 cargo ship during its final approach for an automated docking to the space station in June. 
After deploying a pair of sensor booms for Obstanovka, Vinogradov and Romanenko retrieved the Biorisk experiment from the exterior of Pirs. The Biorisk experiment studied the effect of microbes on spacecraft structures. 
For their final task, the two spacewalkers translated to the Poisk module to retrieve one of two Vinoslivost Materials Sample Experiment panels from the Poisk module. As Vinogradov was removing the panel, it slipped out of his grasp and was irretrievable. The trajectory the panel took will move it away from the space station with no chance of the two making contact. 
This was the 167th spacewalk in support of space station assembly and maintenance, totaling 1,055 hours, 39 minutes. Vinogradov's seven spacewalks total 38 hours, 25 minutes. Romanenko completed his first spacewalk. 
This was the first of as many as six Russian spacewalks planned for this year. Two U.S. spacewalks are scheduled in July. 
During Friday’s spacewalk, Flight Engineers Alexander Misurkin and Chris Cassidy were restricted to their Soyuz TMA-08M spacecraft and the Poisk module to which it is docked. This is a standard procedure during Russian spacewalks as hatches are closed to protect the remainder of the station while still providing crew members access to their Soyuz vehicles. 
Commander Chris Cassidy and Flight Engineer Tom Marshburn, whose Soyuz TMA-07M spacecraft is docked to Rassvet module, had a freer run of the station, including the Zarya module and all modules on the U.S. side of the station. While Vinogradov and Romanenko performed their spacewalk outside the station, Hadfield and Marshburn continued scientific research and maintenance activities inside. 
Marshburn delved into his first onboard session with the BP Reg, a Canadian medical experiment that seeks to understand the causes of fainting and dizziness seen in some station astronauts upon return to Earth. BP Reg collects data before, during and after the mission using inflatable cuffs attached to the legs. The experiment will not only help understand dizziness in astronauts, but also have direct benefits for people on Earth – particularly those predisposed to falls and resulting injuries, as seen in the elderly. 
Marshburn also collected data from NanoRacks and transferred the data to a laptop computer. NanoRacks provides microgravity research facilities for small standardized payloads aboard the station. 
Hadfield retrieved acoustic dosimeters that Cassidy deployed throughout the station Thursday and downloaded the data from these devices to track the noise levels that crew members are exposed to. 
Hadfield also performed some maintenance on the Waste and Hygiene Compartment, one of the toilets aboard the station. The commander rounded out his workday loading software on a laptop computer associated with EXPRESS rack 8. Each of the eight EXPRESS racks aboard the complex provides simple, standard interfaces to accommodate up to ten small payloads, resulting in a total capability to operate up to 80 experiments. 
Over the weekend, the Russian crew members will spend some time drying out their Orlan spacesuits and stowing the tools used in Friday’s spacewalk. All six crew members will participate in weekly housekeeping tasks and enjoy some off-duty time to rest and catch up with friends and family back on Earth. 
Quelle: NASA

Tags: Spacewalk ISS-Crew-35 

2980 Views

Freitag, 19. April 2013 - 12:45 Uhr

Astronomie - "Heinz Haber - von Mannheim zu den Sternen"

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Ausstellung über Heinz Haber in Mannheim
Vom 15.  Mai bis zum 31.  Juli 2013 zeigt das Planetarium Mannheim die Ausstellung "Heinz Haber  – von Mannheim zu den Sternen". Sie widmet sich dem vor hundert Jahren in der Neckarstadt geborenen Astrophysiker und Raumfahrtexperten, der vielen Menschen durch seine Wissenschaftssendungen im Fernsehen bekannt wurde. So sendete die ARD ab dem Jahr 1968 die Serie "Was sucht der Mensch im Weltraum?". Auch als Sachbuchautor machte sich Haber einen Namen, unter anderem mit den Titeln "Brüder im All" und "Der offene Himmel".
Zudem war Haber Mitbegründer und Herausgeber der Zeitschrift "Bild der Wissenschaft". Diesen Medienaktivitäten ging eine berufliche Laufbahn in Deutschland und den USA vor­aus. Mit Untersuchungen im Bereich der Weltraummedizin unterstützte Haber die Pläne Wernher von Brauns für eine bemannte Raumstation. Haber verstarb 1990 in Hamburg. Die dem "Fernsehprofessor" gewidmete Ausstellung kann während der Öffnungszeiten des Planetariums im Foyer besichtigt werden, der Eintritt ist frei. Weitere Informationen: Plane­tarium Mannheim, www.planetarium-mannheim.de
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Prof.Heinz Haber aufgenommen beim CENAP-Besuch von Perry-Rhodan-WeltCon im September 1986
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Freitag, 19. April 2013 - 12:00 Uhr

Raumfahrt - ISS-Spacewalks - Rückblicke

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Russians Outfit the ISS
Russian cosmonauts Gennady Padalka (top), Expedition 32 commander; and Yuri Malenchenko, flight engineer, participate in a session of extravehicular activity (EVA) to continue outfitting the International Space Station. During the five-hour, 51-minute spacewalk on August 20, 2012, Padalka and Malenchenko moved the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module to prepare Pirs for its eventual replacement with a new Russian multipurpose laboratory module. The two spacewalking cosmonauts also installed micrometeoroid debris shields on the exterior of the Zvezda service module and deployed a small science satellite. 
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Expedition 30 Cosmonauts Perform Spacewalk
This image of Russian cosmonauts Oleg Kononenko and Anton Shkaplerov, both Expedition 30 flight engineers, was taken during a spacewalk on Thursday, Feb. 16, 2012. During the six-hour, 15-minute spacewalk, Kononenko and Shkaplerov moved the Strela-1 crane from the Pirs Docking Compartment in preparation for replacing it in 2012 with a new laboratory and docking module. The duo used another boom, the Strela-2, to move the hand-operated crane to the Poisk module for future assembly and maintenance work. Both telescoping booms extend like fishing rods and are used to move massive components outside the station. On the exterior of the Poisk Mini-Research Module 2, they also installed the Vinoslivost Materials Sample Experiment, which will investigate the influence of space on the mechanical properties of the materials. The spacewalkers also collected a test sample from underneath the insulation on the Zvezda Service Module to search for any signs of living organisms. Both spacewalkers wore Russian Orlan spacesuits bearing blue stripes and equipped with NASA helmet cameras.
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Sunita Williams on Spacewalk
NASA astronaut Sunita Williams, Expedition 32 flight engineer, appears to touch the bright sun during the mission’s third session of extravehicular activity (EVA) on Sept. 5, 2012. 
During the six-hour, 28-minute spacewalk, Williams and Japan Aerospace Exploration Agency astronaut Aki Hoshide (visible in the reflections of Williams’ helmet visor), flight engineer, completed the installation of a Main Bus Switching Unit (MBSU) that was hampered by a possible misalignment and damaged threads where a bolt must be placed. They also installed a camera on the International Space Station’s robotic arm, Canadarm2.
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ISS28-E-005403 (25 May 2011) --- At one of the International Space Station's trusses, NASA astronaut Michael Fincke is pictured during the STS-134 mission's third spacewalk. Astronauts Fincke and Andrew Feustel (out of frame), both mission specialists, coordinated their shared activity with NASA astronaut Greg Chamitoff (out of frame), who stayed in communication with the pair and with Mission Control Center in Houston from the shirt sleeve environment inside the station.
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Cosmonauts Conduct Spacewalk
Cosmonauts Sergei Volkov and Alexander Samokutyaev (out of frame), attired in Russian Orlan spacesuits, conducted a spacewalk on Wednesday, Aug. 3, 2011, on the Russian segment of the International Space Station. During the six-hour, 23-minute spacewalk, the Expedition 28 flight engineers moved a cargo boom from one airlock to another, installed a prototype laser communications system and deployed an amateur radio micro-satellite.
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Work Is a Spacewalk
During the STS-131 mission's first spacewalk, astronauts Rick Mastracchio and Clayton Anderson (out of frame) moved a new 1,700-pound ammonia tank from space shuttle Discovery's cargo bay to a temporary parking place on the station, retrieved an experiment from the Japanese Kibo Laboratory exposed facility and replaced a Rate Gyro Assembly on one of the truss segments.
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ISS018-E-039022 (10 March 2009) --- Astronaut Michael Fincke, Expedition 18 commander, participates in a session of extravehicular activity (EVA) to perform maintenance on the International Space Station. During the 4-hour, 49-minute spacewalk, Fincke and cosmonaut Yury Lonchakov (out of frame) reinstalled the Exposing Specimens of Organic and Biological Materials to Open Space (Expose-R) experiment on the universal science platform mounted to the exterior of the Zvezda Service Module. The spacewalkers also removed straps, or tape, from the area of the docking target on the Pirs airlock and docking compartment. The tape was removed to ensure it does not get in the way during the arrival of visiting Soyuz or Progress spacecraft. Photo credit: NASA
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ISS017-E-011302 (15 July 2008) --- Russian Federal Space Agency cosmonaut Sergei Volkov, Expedition 17 commander, participates in a session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the five-hour, 54-minute spacewalk, Volkov and cosmonaut Oleg Kononenko (out of frame), flight engineer, continued to outfit the station's exterior, including the installation of a docking target on the Zvezda Service Module. Photo credit: NASA
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ISS017-E-011310 (15 July 2008) --- This close-up view shows reflections in the visor of Russian Federal Space Agency cosmonaut Oleg Kononenko, Expedition 17 flight engineer, as he participates in a session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. Visible in the reflections in the visor are cosmonaut Sergei Volkov, commander, and various components of the station. During the five-hour, 54-minute spacewalk, Kononenko and Volkov continued to outfit the station's exterior, including the installation of a docking target on the Zvezda Service Module. Photo credit: NASA 
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ISS014-E-13326 (4 Feb. 2007) --- Astronaut Sunita L. Williams, Expedition 14 flight engineer, uses a digital still camera to expose a photo of her helmet visor during today's session of extravehicular activity (EVA) as construction continues on the International Space Station. Also visible in the reflections in the visor is a solar array wing. During the spacewalk, Williams and Michael E. Lopez-Alegria (out of frame), commander and NASA space station science officer, reconfigured the second of two cooling loops for the Destiny laboratory module, secured the aft radiator of the P6 truss after retraction and prepared the obsolete Early Ammonia Servicer (EAS) for removal this summer. 
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ISS014-E-09795 (14 Dec. 2006) --- European Space Agency (ESA) astronaut Christer Fuglesang, STS-116 mission specialist, participates in the mission's second of three planned sessions of extravehicular activity (EVA) as construction resumes on the International Space Station. Astronaut Robert L. Curbeam, Jr. (out of frame), mission specialist, also participated in the spacewalk. 
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S128-E-007035 (1 Sept. 2009) --- Astronaut Nicole Stott, Expedition 20 flight engineer, participates in the STS-128 mission's first session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the six-hour, 35-minute spacewalk, Stott and astronaut John "Danny" Olivas (out of frame), mission specialist, removed an empty ammonia tank from the station's truss and temporarily stowed it on the station's robotic arm. Olivas and Stott also retrieved the European Technology Exposure Facility (EuTEF) and Materials International Space Station Experiment (MISSE) from the Columbus laboratory module and installed them on Discovery's payload bay for return.
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SS020-E-038055 (3 Sept. 2009) --- A portion of the International Space Station is featured in this image photographed by a space walking astronaut during the STS-128 mission's second session of extravehicular activity (EVA) as construction and maintenance continue on the station. The blackness of space and Earth's horizon provide the backdrop for the scene.
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SS020-E-038470 (5 Sept. 2009) --- NASA astronaut John "Danny" Olivas, STS-128 mission specialist, participates in the mission's third and final session of extravehicular activity (EVA) as construction and maintenance continue on the International Space Station. During the seven-hour, one-minute spacewalk, Olivas and European Space Agency astronaut Christer Fuglesang (out of frame), mission specialist, deployed the Payload Attachment System (PAS), replaced the Rate Gyro Assembly #2, installed two GPS antennae and did some work to prepare for the installation of Node 3 next year. During connection of one of two sets of avionics cables for Node 3, one of the connectors could not be mated. This cable and connector were wrapped in a protective sleeve and safed. All other cables were mated successfully.
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Between Earth and Space
Astronaut Robert L. Behnken, STS-123 mission specialist, participates in the mission's third scheduled spacewalk. During the 6-hour, 53-minute spacewalk, Behnken and Rick Linnehan installed a spare-parts platform and tool-handling assembly for Dextre, also known as the Special Purpose Dextrous Manipulator. Among other tasks, they also checked out and calibrated Dextre's end effector and attached critical spare parts to an external stowage platform. The new robotic system was activated on a power and data grapple fixture located on the Destiny laboratory on flight day nine. The blackness of space and Earth's horizon provide the backdrop for the scene. 
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Preparing for the Future
Astronaut Mike Fossum continues his duties during this the second of the STS-124mission's three scheduled spacewalk. During the seven-hour, 11-minute spacewalk, Fossum and fellow astronaut Ron Garan installed television cameras on the front and rear of the Kibo Japanese Pressurized Module (JPM) to assist Kibo robotic arm operations, removed thermal covers from the Kibo robotic arm, prepared an upper JPM docking port for flight day seven's attachment of the Kibo logistics module. 
They also readied a spare nitrogen tank assembly for its installation during the third spacewalk, retrieved a failed television camera from the Port 1 truss and inspected the port Solar Alpha Rotary Joint.
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Preparing Kibo's New Home
Astronaut Mike Fossum used a digital camera to create this self-portrait during the STS-124 mission's first scheduled spacewalk. During the six-hour, 48-minute spacewalk, Fossum and fellow astronaut Ron Garan prepared the Kibo Japanese Pressurized Module for its installation to the space station. Kibo was officially opened during a ceremony performed by astronaut Akihiko Hoshide and the Expedition 17 and STS-124 crew the following day, Wednesday, June 4, 2008.
During the spacewalk, Fossum and Garan also loosened restraints holding the Orbiter Boom Sensor System in its temporary stowage location on the space station's starboard truss, demonstrated cleaning techniques for the Solar Alpha Rotary Joint's (SARJ) race ring and installed a replacement SARJ Trundle Bearing Assembly.
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S123-E-008475 (23 March 2008) --- Astronaut Mike Foreman, STS-123 mission specialist, helps to tie down the Orbiter Boom Sensor System on the International Space Station's S1 truss during EVA 5 on March 22. The structure at the end of the boom is a transmission device for laser imagery from the laser devices used for scanning the thermal protection system.
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Dangerous Maneuvers
While anchored to a foot restraint on the end of the Orbiter Boom Sensor System, astronaut Scott Parazynski assesses his repair work as the solar array is fully deployed during the STS-120 mission's fourth spacewalk. During the 7-hour, 19-minute spacewalk, Parazynski cut a snagged wire and installed improvised stabilizers designed to strengthen the damaged solar array's structure and stability in the vicinity of the damage. 
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Building the New World
European Space Agency astronaut Hans Schlegel worked on the new Columbus laboratory during the STS-122 mission's second spacewalk. During the six-hour, 45-minute spacewalk, Schlegel and NASA astronaut Rex Walheim (out of frame) worked to replace a nitrogen tank used to pressurize the station's ammonia cooling system.
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Suiting Up
Attired in his Russian Orlan spacesuit, Russian Federal Space Agency cosmonaut Oleg Kononenko, Expedition 17 flight engineer, prepared for the July 10 spacewalk. During the full dress rehearsal "dry run" that took place on July 8, Kononenko and fellow cosmonaut Commander Sergei Volkov tested translation capability and the status of the suits' communications gear and other systems while in the Pirs Docking Compartment of the International Space Station.
Durin the 6-hour, 18-minute spacewalk, they inspected their Soyuz TMA-12 spacecraft and retrieved a pyro bolt from it. Image Credit: NASA
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Out on a Limb
Anchored to a Canadarm2 mobile foot restraint, astronaut Rick Linnehan participates in the mission's first scheduled spacewalk. During the seven-hour spacewalk, Linnehan and Expedition 16 flight engineer Garrett Reisman prepared the Japanese logistics module-pressurized section for removal from Endeavour's payload bay and installed the tool change out mechanisms on the Canadian-built Dextre robotic system, the final element of the station's Mobile Servicing System. 
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The View From Above
Visible through a window on Endeavour's aft flight deck, astronaut Rick Linnehan participates in the mission's third scheduled spacewalk. During the 6-hour, 53-minute spacewalk, Linnehan and astronaut Robert L. Behnken installed a spare-parts platform and tool-handling assembly for Dextre, also known as the Special Purpose Dextrous Manipulator. Among other tasks, they also checked out and calibrated Dextre's end effector and attached critical spare parts to an external stowage platform. The new robotic system is scheduled to be activated on a power and data grapple fixture located on the Destiny laboratory on flight day nine. 
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Quelle: NASA

Tags: ISS-Spacewalks 

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Donnerstag, 18. April 2013 - 22:21 Uhr

Astronomie - Bislang aussichtsreichste Kandidaten für lebensfreundliche Exoplaneten gefunden

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Ein internationales Wissenschaftlerteam, zu dem auch Lisa Kaltenegger (Max-Planck-Institut für Astronomie) gehört, hat die Entdeckung zweier potenziell erdähnlicher Planeten, Kepler-62e und Kepler-62f mit dem NASA-Weltraumteleskop Kepler bekanntgegeben, die sich in der habitablen Zone des Sterns Kepler-62 befinden. Ihren Radien nach zu urteilen, sollte es sich um Felsplaneten handeln. Damit wären dies die bislang besten Kandidaten für lebensfreundliche Planeten. Die Untersuchungen von Dr. Kaltenegger zeigen, dass beide Planeten in der sogenannten habitablen Zone ihres Sterns liegen, in der flüssiges Wasser vorkommen kann – die Voraussetzung für Leben, wie wir es kennen.

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Abbildung 1: Ein Vergleich des Planetensystems um den Stern Kepler-62 mit unserem eigenen Sonnensystem. Die Planetenumlaufbahnen (oben und unten) sind relativ zueinander im richtigen Maßstab. Die Planetengrößen selbst (Mitte) sind untereinander ebenfalls im richtigen Maßstab. Die habitable Zone – befindet sich dort ein Planet, kann auf dessen Oberfläche prinzipiell flüssiges Wasser existieren – ist grün eingezeichnet. Kepler-62e und Kepler-62f sind die bislang besten Kandidaten für lebensfreundliche Planeten: Planeten mit fester Oberfläche, die sich in der habitablen Zone ihres Sterns befinden.

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Die Entdeckung zweier Planetensysteme um die Sterne Kepler-62 und Kepler-69 wurde heute, Donnerstag, den 18. April um 11 Uhr lokaler Zeit (20 Uhr MESZ) auf einer Pressekonferenz im Ames Research Center der NASA in Moffett Field, California bekanntgegeben. Auf dem Podium saßen unter anderem NASAs Direktor für Astrophysik, Paul Hertz, der Chefwissenschaftler der Kepler-Mission William Borucki, und Lisa Kaltenegger vom Max-Planck-Institut für Astronomie. Kaltenegger, die außerdem noch mit dem Harvard-Smithsonian Center for Astrophysics in Boston affiliiert ist, ist kein Mitglied des Kepler-Teams, war aber dafür verantwortlich, die potenzielle Lebensfreundlichkeit der Planeten des Kepler-62-Systems abzuschätzen.
Der Stern Kepler-62 im Sternbild Leier, rund 1200 Lichtjahre von der Erde entfernt, ist ein wenig kleiner und kühler als unsere Sonne (Spektraltyp von Kepler-62: K2V; geschätzte Masse: 0,7 Sonnenmassen; geschätzter Radius 0,63 Sonnenradien). Sein Planetensystem ist gerade so ausgerichtet, dass die Planeten aus Sicht eines Beobachters auf der Erde in regelmäßigen Abständen vor ihrem Mutterstern vorbeilaufen und dabei einen Bruchteil des Sternenlichts abschatten. Auf diese Weise (»Transitmethode«) kann das Weltraumteleskop Kepler, das extrem genaue Helligkeitsmessungen durchführen kann, Planeten um ferne Sterne nachweisen. Das gelang auch bei dem Stern, der entsprechend des für das Weltraumteleskop benutzten Katalogs die Bezeichnung Kepler-62 trägt: Hier wies Kepler fünf Planeten nach, die den üblichen Konventionen folgend Kepler-62b bis Kepler-62f genannt wurden.
Ein wichtiger Aspekt der Erforschung von Exoplaneten ist die Suche nach Planeten, auf denen die richtigen Bedingungen für Leben herrschen könnten – ein Schritt in Richtung auf das Ziel, Leben auf fernen Planeten tatsächlich nachzuweisen. Gerade in dieser Hinsicht sind die neuentdeckten Planeten Kepler-62e und Kepler-62f hochinteressant. Lisa Kaltenegger, Expertin für die Atmosphären insbesondere erdähnlicher Exoplaneten und die Wissenschaftlerin, die die entsprechenden Analysen für das Kepler-62-System durchführte, erklärt:
»Ich habe von dieser spannenden Entdeckung erstmals von William Borucki gehört, der mich im Oktober 2012 auf einer Konferenz ansprach. Das Kepler-Team hat mich dann gebeten, zu untersuchen, ob Kepler-62e oder Kepler-62f in die lebensfreundliche 'habitable Zone' ihres Heimatsterns fallen. Wie sich herausstellt, ist das der Fall – und diese Planeten sind etwas ganz Besonderes, weil sie die bislang kleinsten sind, die wir in der habitablen Zone eines Sterns gefunden haben.«
Der Radius von Kepler-62e ist 1,61 mal so groß wie jener der Erde, der von Kepler-62f 1,41 mal so groß. Zuvor war der kleinste Planet in einer habitablen Zone, dessen Radius bekannt war, Kepler-22b gewesen, mit dem 2,4-fachen Erdradius.
»Bisher waren alle interessanten Planeten in habitablen Zonen solche, die mit der sogenannten Radialgeschwindigkeitsmethode nachgewiesen worden waren. Dieses Verfahren liefert aber naturgemäß nur eine Untergrenze für die Masse eines Planeten, und keine Information über seinen Radius. Allein aufgrund der Masse ist es aber schwierig zu beurteilen, ob es sich um einen erdartigen Planeten, also einen Planeten mit fester Oberfläche handelt. Ein Radius von weniger als dem Doppelten des Erdradius ist dagegen ein deutliches Zeichen, das es sich um einen erdähnlichen Planeten handelt – es sei denn, wir betrachteten einen Planeten, der einen äußerst jungen Stern umkreist.«
Dass es sich bei den neuentdeckten Planeten tatsächlich um Felsplaneten mit solider Oberfläche handelt, und nicht um Gasplaneten wie Jupiter oder Neptun, ist ein Schlüsselaspekt der neuen Entdeckung. Die interessantesten sicheren Kandidaten für habitable Planeten, die bislang bekannt sind (GJ 667Cc, Gl 581d, HD 85512b und Gl 163c) wurden sämtlich mit der Radialgeschwindigkeitsmethode nachgewiesen, die lediglich Rückschlüsse auf die Mindestmasse des untersuchten Planeten zulässt. Wahrscheinlichkeitsüberlegungen zeigen, dass die tatsächliche Masse des Planeten in den meisten Fällen zwischen dieser Mindestmasse und dem Doppelten der Mindestmasse liegt. Für die erwähnten Kandidaten würde dies bedeuten, dass es sich um Felsplaneten, aber durchaus auch um Miniaturversionen des Neptun handeln könnte. Ein warnendes Beispiel ist der Planet Kepler-11f, ein Mini-Neptun mit 2,3 Erdmassen und dem 2,6fachen des Erdradius.
»Aussagen über die Lebensfreundlichkeit eines Planeten hängen immer von zusätzlichen Annahmen ab. Nehmen wir an, bei Kepler-62e und -62f handle es sich in der Tat um Felsplaneten, wie ihre Radien nahelegen. Nehmen wir weiterhin an, dass es auf diesen Planeten Wasser gibt, und dass ihre Atmosphäre eine ähnliche Zusammensetzung hat wie jene der Erde, also vor allem Stickstoff, mit Anteilen von Wasser und Kohlenstoffdioxid. Unter diesen Voraussetzungen könnten beide Planeten flüssiges Wasser auf ihrer Oberfläche besitzen. Kepler-62f empfängt weniger Strahlungsenergie von seinem Stern als die Erde von der Sonne und würde dementsprechend mehr Treibhausgase benötigen als die Erde, etwa Kohlenstoffmonoxid, um nicht einzufrieren. Kepler-62e ist seinem Stern näher und benötigt eine hinreichend dichte Wolkendecke, mit der er Strahlungsanteile des Sterns reflektieren kann, damit flüssiges Wasser auf seiner Oberfläche möglich ist.«
Ob ein Planet lebensfreundlich ist oder nicht, entscheiden die Wissenschaftler dabei daran, ob auf ihm flüssiges Wasser existieren kann – die Voraussetzung für Leben, wie wir es kennen. Ob er im astronomischen Sinne habitabel ist (in der habitablen Zone seines Sterns liegt) ist ein noch etwas schärferes Kriterium – es setzt die Möglichkeit voraus, dass es auf der Oberfläche des Planeten flüssiges Wasser gibt. Das ist dem derzeitigen Stand nach die Voraussetzung dafür, dass sich Leben auf diesem Planeten möglicherweise in Zukunft mithilfe astronomischer Beobachtungen nachweisen lässt.
Habitabilität bedeutet nicht notwendigerweise, dass der betreffende Planet bis ins Detail so aussieht wie die Erde. Im Gegenteil wären Planeten mit hinreichend größerem Radius als die Erde, wie Kepler-62e und Kepler-62f, bei gleicher chemischer Zusammensetzung höchstwahrscheinlich Wasserwelten, deren Oberfläche von einem tiefen, globalen Ozean bedeckt ist.
Das Ergebnis der Habitabilitäts-Analyse zeigt nicht, dass der betreffende Planet tatsächlich habitable ist – nur, dass er es, die richtigen Atmosphärenbedingungen vorausgesetzt, sein könnte. Ein definitiver Nachweis ist derzeit noch Zukunftsmusik. Er kann erst gelingen, wenn mit größeren Teleskopen als den derzeit verfügbaren eine spektroskopische Analyse von Planetenatmosphären möglich wird, man also eine Art »chemischen Fingerabdruck« des Planeten bekommen kann. Ein wichtiger Teil der Arbeit von Kaltenegger und ihren Mitarbeitern besteht darin, Modellrechnungen anzustellen, wie die chemischen Fingerabdrücke bestimmter Sorten von Planet, eben beispielsweise auch Kepler-62e und -62f, aussehen können.
Letztlich könnten diese zukünftigen Beobachtungen sogar die chemischen Spuren von Leben auf einem anderen Planeten zutage fördern. Aber bis solche direkten Messungen möglich sind, können wir nicht mehr tun, als die Habitabilität neu entdeckter Planeten unter Einbeziehung aller verfügbaren Daten abzuschätzen – und eine solche Abschätzung zeigt, dass Kepler-62e und -62f die aussichtsreichsten Kandidaten sind, von denen wir bislang wissen.
Kaltenegger schließt:
»Was Kepler-62e und Kepler-62f so spannend macht, ist zweierlei: Zum einen kennen wir ihren Radius, und der weist daraufhin, dass es sich in der Tat um erdähnliche Planeten handelt. Außerdem liegen diese Planeten in der habitablen Zone ihres Sterns. Das macht sie zu den besten Kandidaten für habitable Planeten, die wir kennen. Und es war sehr aufregend für mich, bei dieser bahnbrechenden Entdeckung der Kepler-Mission dabei gewesen zu sein.«
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Abbildung 2: Massen und Größen (Radien) für ausgewählte Planeten. Die eingezeichneten Kurven zeigen den Zusammenhang zwischen Masse und Radius (entspricht der mittleren Dichte) für verschiedene Sorten von Planeten. Die blaue Linie beispielsweise entspricht Planeten, die überwiegend (75%) aus Wasser bestehen, die schwarze Linie solchen, die wie unsere Erde überwiegend aus Fels bestehen (hier vertreten durch das Mineral Enstatit, MgSiO3, aus der Gruppe der Pyroxene, welche den Großteil des Erdmantels ausmachen) usw. Die gemessenen Radien von Kepler-62e und Kepler-62 plus eine Abschätzung ihrer Massen sind als blaue Flächen eingezeichnet und eigen, dass es sich mit hoher Wahrscheinlichkeit um erdähnliche Planeten handelt: Planeten mit einer festen (obschon möglicherweise ozeanbedeckten) Oberfläche. Kepler-11f, ein Mini-Neptun, zeigt beispielhaft, dass eine verhältnismäßig niedrige Masse alleine noch nicht heißt, dass man es mit einem erdähnlichen Planeten zu tun hat.
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Abbildung 3: Die habitable Zone, in der flüssiges Wasser auf einer Planetenoberfläche existieren kann, für verschiedene Arten von Stern. Oben sind die inneren Planeten unseres eigenen Sonnensystems zu sehen, von denen sich Erde und Mars in der habitablen Zone befinden. Kepler-62 ist deutlich kühler als die Sonne, und Kepler-62e und -62f befinden sich in seiner habitablen Zone. Für Kepler-69c, dessen Entdeckung ebenfalls heute bekanntgegeben wurde, ist der Energieausstoß seines Sterns nicht genau genug bekannt; die Messgenauigkeit lässt zu, dass sich auch dieser Planet möglicherweise in der habitablen Zone seines Sterns befindet. Kepler-22b, der bis zu den jüngsten Entdeckungen kleinste Planet in der habitablen Zone seines Sterns, ist mit großer Wahrscheinlichkeit ein Mini-Neptun, kein erdähnlicher Planet. Was hier als empirische habitable Zone bezeichnet wird bezeichnet den Abstandsbereich, in dem flüssiges Wasser auf der Planetenoberfläche existieren kann, falls der betreffende Planet eine ausreichende Wolkendecke besitzt. In der konservativen habitablen Zone kann flüssiges Wasser auf der Planetenoberfläche auch ohne das Vorliegen einer Wolkendecke existieren.
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Quelle: 
Max-Planck-Institut für Astronomie - Heidelberg

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