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Sonntag, 6. März 2016 - 21:45 Uhr

Astronomie - Cassini findet "magische Insel" in Kohlenwasserstoff Meer von Titan

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This image shows the evolution of a transient feature in the large hydrocarbon sea named Ligeia Mare.
NASA/JPL-Caltech/ASI/Cornell
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By comparing radar images of Saturn's exotic moon Titan, scientists have found a bright, island-like feature that has changed over time. The images, captured by the Cassini spacecraft from 2007 through 2015, show this "magic island" brightening and then dimming again.
From studying the images, scientists conclude the brightening is most likely due to waves at or beneath the surface. They do not think it's likely to be caused by tides or sea level or seafloor changes. The surface of Titan is extremely cold, on average about -180ºC, but methane and other hydrocarbons on its surface can still exist in liquid form. The "lake" shown in this image, Ligeia, is Titan's second-largest liquid hydrocarbon sea. With an area of about 130,000 square kilometers, it is nearly as large as the Caspian Sea, Earth's largest lake.
Previous images indicate other, similar features exist in Kraken Mare, Titan's largest hydrocarbon sea. With these observations, planetary scientists are beginning to understand that this moon's oceans are not stagnant, but are instead dynamic environments. Cassini will have one more opportunity to look for "magic island" in 2017, during its final, close flyby.
Until recently, it seemed unlikely NASA would visit Titan again any time soon. In the final 2016 federal budget, however, the US Congress created an Ocean Worlds exploration program. It directs NASA to begin designing missions to explore the cold, icy moons of the outer Solar System, including Europa, Titan, and another of Saturn's moons, Enceladus. These, and other worlds around Jupiter and beyond are thought to harbor liquid oceans in some form or another.
The director of NASA's Jet Propulsion Laboratory, Charles Elachi, testified at a hearing of the House Appropriations subcommittee regarding this Ocean Worlds program last Thursday. He noted that Titan is a totally new frontier for organic chemistry—a place where an entirely different kind of life might have evolved.
"Titan is a world full of organic molecules, which are of course key building blocks for life," Elachi said. "Clouds in Titan’s atmosphere rain out liquid methane and ethane, which then collects into lakes that dot Titan’s Earth-like landscape. On Earth, however, our lakes are carved into rock, whereas on Titan the lakes of methane and ethane are carved into a shell of water ice. Beneath Titan’s icy shell may reside a global liquid water ocean. Could life have arisen on such a world? For many in the planetary science community, Titan is heralded as the place to go to look for "weird life"—life unlike life as we know it, life that may have originated in liquid methane instead of liquid water."
Quelle: ars technica

Tags: Astronomie 

1627 Views

Sonntag, 6. März 2016 - 21:30 Uhr

Science - Physiker demonstrieren erstmals die Teleportation eines klassischen Objekts

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Jun.-Prof. Dr. Alexander Szameit (r.) und Dr. Marco Ornigotti zeigen ihre Modelle der Enterprise. Die Physiker haben jetzt erstmals experimentell demonstriert, dass das Konzept der Teleportation nicht nur in der Welt winziger Quantenteilchen, sondern auch in der klassischen Welt Bestand hat.

Star Trek-Vision wird Wirklichkeit
Physiker demonstrieren erstmals die Teleportation eines klassischen Objekts 
"Beam me up, Scotty", auch wenn Captain Kirk diesen Satz so nie gesagt haben soll, hält er sich als geflügeltes Wort bis heute. Wann immer der Chef des TV-Serien-Raumschiffs Enterprise zurück in seine Steuerzentrale wollte, genügte dieses Kommando und im selben Augenblick schon war er dort - ohne Zeitverlust durch die unendlichen Weiten des Weltraums.
Alles Science Fiction, erdacht in den 60er Jahren des vergangenen Jahrhunderts? Nicht ganz: Physiker sind tatsächlich in der Lage, zwar keine massiven Teilchen, so aber doch deren Eigenschaften zu beamen bzw. zu "teleportieren", wie es in der Fachsprache heißt.
Information ohne Zeitverlust übertragen
"Viele der damals revolutionär anmutenden Ideen aus der Star-Trek-Serie sind inzwischen Realität geworden", weiß Prof. Dr. Alexander Szameit von der Friedrich-Schiller-Universität Jena. "Sich selbst öffnende Türen, die Videotelefonie oder das aufklappbare Handy, all das haben wir zuerst in der Enterprise gesehen", so der Juniorprofessor für Diamant-/Kohlenstoff-basierte optische Systeme. Warum also nicht auch teleportieren? "Elementarteilchen wie Elektronen oder Lichtteilchen existieren per se in einem räumlich nicht abgegrenzten Zustand", sagt Szameit. Daher sei es für solche Teilchen möglich, mit einer gewissen Wahrscheinlichkeit zeitgleich an unterschiedlichen Orten zu sein. "Innerhalb eines solchen, über mehrere Orte verteilten Systems, lassen sich Informationen von einem Ort zum anderen ohne Zeitverlust übertragen." Dieser Vorgang ist als sogenannte Quantenteleportation bereits seit einigen Jahren bekannt.
Das Forscherteam um den Star-Trek-Fan Szameit hat nun jedoch erstmals experimentell demonstriert, dass das Konzept der Teleportation nicht nur in der Welt winziger Quantenteilchen, sondern auch in unserer klassischen Welt Bestand hat. Das berichten die Wissenschaftler im Fachmagazin "Laser & Photonics Reviews" (DOI: 10.1002/lpor.201500252).
Eigenschaften von Licht verschränken
Dazu nutzten die Forscher eine besondere Form von Laserstrahlen. "Ähnlich wie die physikalischen Zustände in einem Elementarteilchen lassen sich auch die Eigenschaften von Lichtstrahlen miteinander verschränken", erklärt Dr. Marco Ornigotti aus Szameits Team. Als "Verschränkung" bezeichnen die Physiker eine Art Kodierung. "Man verknüpft die zu übertragende Information mit einer bestimmten Eigenschaft des Lichts", so Ornigotti, der die Experimente für die nun vorgelegte Studie geleitet hat.
Im konkreten Fall haben die Physiker Information in einer bestimmten Polarisationsrichtung des Laserlichts kodiert und diese mittels Teleportation auf die Form des Laserstrahls übertragen. "Bei dieser Form der Teleportation können wir jedoch nicht beliebige Distanzen überspringen", schränkt Physiker Szameit ein, "im Gegenteil, die klassische Teleportation funktioniert ausschließlich lokal." Doch genau wie im Teleporter des Raumschiffs Enterprise oder bei der Quantenteleportation erfolgt die Informationsübertragung vollständig und sofort, ohne jeglichen Zeitverlust. Das mache eine solche Informationsübertragung für mögliche Anwendungen etwa in der Telekommunikation hochinteressant, wie Szameit unterstreicht. 
Quelle: Friedrich-Schiller-Universität Jena
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German scientists successfully teleport classical information
Using a series of laser beams, a pair of German scientists successfully teleported classical information without the transfer or matter or energy.
Researchers have previously demonstrated local teleportation within the world of quantum particles. But the latest experiment successfully translates the phenomenon for classical physics.
"Elementary particles such as electrons and light particles exist per se in a spatially delocalized state," Alexander Szameit, a professor at the University of Jena, explained in a press release.
In other words, these particles can be in two places at the same time.
"Within such a system spread across multiple locations, it is possible to transmit information from one location to another without any loss of time," Szameit.
By coupling the properties of classical information, researchers were able to use quantum teleportation for classical teleportation. Classical information is coupled using a process called "entanglement."
"As can be done with the physical states of elementary particles, the properties of light beams can also be entangled," said researcher Marco Ornigotti. "You link the information you would like to transmit to a particular property of the light."
Researchers used polarization to encode information within a laser beam, enabling the teleportation of information instantly and in its entirety without loss of time.
Whereas quantum information and quantum systems describe particle properties that are inferred, classical information describes physical properties directly measured.
The first-of-its-kind demonstration was detailed this week in the journal Laser & Photonics Reviews.
Quelle: SD

Tags: Science 

1402 Views

Sonntag, 6. März 2016 - 10:00 Uhr

Science-Fiction - Das erstaunliche Design bei der NASA für Star Trek-Raumschiff , IXS Enterprise

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“Warp speed, Mr. Sulu” (courtesy of Mark Rademaker/Flickr)
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NASA engineer and physicist Harold White announced a few years ago that he was working on a potentially groundbreaking idea that could allow space travel faster than the speed of light. Yes, like in “Star Trek.”
And now, to boldly go where no designer has gone before, Mark Rademaker — who is collaborating with White — has created a CGI design concept for the “warp ship.” They’re calling it the IXS Enterprise.
“We wanted to have a decent image of a theory conforming Warp ship to motivate young people to pursue a STEM career,” Rademaker said in an e-mail interview. “It does have some Sci-Fi features that might never transfer to a possible final design, unless we really want to.”
A warp ship such as the IXS Enterprise could allow travel to interstellar space in a matter of weeks rather than, say, centuries. And the science behind why it might be possible is truly mind-boggling.
An over-simplified explanation is that the concept seeks to exploit a “loophole” in Albert Einstein’s theory of relativity that allows travel faster than the speed of light by expanding space-time behind the object and contracting space-time front of it. Io9 explains more:
Essentially, the empty space behind a starship would be made to expand rapidly, pushing the craft in a forward direction — passengers would perceive it as movement despite the complete lack of acceleration.
White speculates that such a drive could result in “speeds” that could take a spacecraft to Alpha Centauri in a mere two weeks — even though the system is 4.3 light-years away.
White, whose title is “Advanced Propulsion Theme Lead for the NASA Engineering Directorate,” has mathematically calculated a plausible way to accomplish this using far less energy than required by the original theory, which was proposed in 1994 by physicist Miguel Alcubierre.
His concept requires using large rings that surround the spacecraft (which you can see in the image above) to greatly reduce the amount of energy needed to warp space-time in front of and behind the spacecraft.
“The rings are most important as they will form the Warp bubble,” Rademaker said in his e-mail. “The way they are designed now will reduce the energy requirement needed to form the bubble. (By quite a large factor.) Also we tried to fill up as much space within the rings, it’s expensive to leave that open or unused.”
White and his team at NASA’s Eagleworks Labs are now working to create a “proof of concept” for this idea.
So how quickly can this all become a reality? According to White, in an interview with i09, proving that the math can become a reality in the lab is the first and probably most important step in the process:
What White is waiting for is existence of proof — what he’s calling a “Chicago Pile” moment — a reference to a great practical example.
“In late 1942, humanity activated the first nuclear reactor in Chicago generating a whopping half Watt — not enough to power a light bulb,” he said. “However, just under one year later, we activated a ~4MW reactor which is enough to power a small town. Existence proof is important.”
Rademaker’s design is posted in his Flickr account, and we’ve included the images with his permission:
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Quelle: The Washington Post

Tags: Science IXS Enterprise 

2515 Views

Sonntag, 6. März 2016 - 09:15 Uhr

Astronomie-History - Kosmos 1942: Der Himmel als Kompass

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Aus dem CENAP-Archiv:

KOSMOS

Quelle: CENAP-Archiv


Tags: Astronomie 

1216 Views

Samstag, 5. März 2016 - 20:00 Uhr

Luftfahrt-History - 1930: Dänemarks NAVY erstaunliche Unterseeboot-Flugzeug Studie

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Aus dem CENAP-Archiv:

Quelle: CENAP-Archiv


Tags: Luftfahrt 

1244 Views

Samstag, 5. März 2016 - 17:00 Uhr

Raumfahrt - ESA-Sonde Rosetta/Philae auf Komet 67P/Churyumov-Gerasimenko - Update-46

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27.01.2016

COMETWATCH 17 JANUARY
Today's CometWatch features a NAVCAM image taken on 17 January 2016, when Rosetta was 83.4 km from the comet nucleus. The scale is 7.1 m/pixel and the image measures 7.3 km across.
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Enhanced NAVCAM image of Comet 67P/C-G taken on 17 January 2016, 83.4 km from the nucleus. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
The image shows 67P/C-G with the large lobe on the left and the small one on the right, in a similar orientation to that of CometWatch 16 August 2015. In that image, taken only three days after perihelion, the comet's spectacular activity dominated the view, while today's image reveals more of the diversity of terrains that are found on the surface.
In the upper part, we see a rough portion of the Khepry region (on the left) and a seemingly smoother portion of Aker (on the right). These two areas were often portrayed in CometWatch entries from April and May 2015, for example in this image from 21 May.
Towards the left edge of the nucleus, this view reveals the narrow and elongated Aten. At the centre of the large lobe is the Babi region, bridging to the dust covered terrains of Ash on the lower left and to Seth, which is almost entirely cast in shadow, on the lower right.
This image also beautifully portrays the string of boulders on the smooth Hapi region, on the 'neck' of the comet, leading towards the more rugged Sobek towards the top right.
On the small lobe, we see the rough Bastet region (top) neighbouring smoother portions of Ma'at (bottom). To the right, the large circular depression of Hatmehit is depicted in a striking contrast of bright and shadowed areas that reveal many boulders lying in this region.
You can use the interactive comet viewer tool to explore the various regions of the surface of 67P/C-G.
The original 1024 x 1024 image is provided below.
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TWIN TAILS
Amateur and professional astronomers alike have been monitoring changes in Comet 67P/Churyumov-Gerasimenko’s tail, which, since December, has been exhibiting two prominent structures.
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Image of 67P/C-G obtained with the 2.5m Isaac Newton Telescope on La Palma on the morning of 19 January 2016. The picture was taken through a red filter; the apparent colour has been added to help pick out faint structures by eye. The tail extends 0.5 degrees from the nucleus (the apparent size of the full moon) before reaching the edge of the image, corresponding to a minimum length of 2.2 million km. Note that the thick black lines are gaps between CCDs in the array (the camera has 4 CCDs to cover half a degree). Credit: Alan Fitzsimmons / Isaac Newton Telescope.
“Current indications from the data we’re collecting of Comet 67P/C-G is that both features are dust structures,” says professional astronomer Alan Fitzsimmons, who has recently spent time observing the comet with the Isaac Newton Telescope in La Palma.
Multiple tail structures are not uncommon in comets, and indeed have been observed during previous apparitions of Comet 67P/C-G.
The two portions of the tail are attributed to different populations of dust grains swept away from the comet’s nucleus by the radiation pressure of the Sun over the course of its 6.5 year orbit around the Sun.
In the image above, taken with the 2.5m Isaac Newton Telescope on La Palma, the upper ‘streamer’ is precisely aligned along the projected orbit of the comet, implying it is made of large and/or old dust grains moving slowly along the orbit of comet. This part is called a comet dust trail because it is formed from the particles trailing along the path of a comet. This dust trail of Comet 67P/C-G has been seen several times before by both ground-based telescopes and space-based infrared observatories.
The lower portion of the dust tail exhibits a thin central core and resembles a feature called a neckline structure. This is formed from dust grains released on the “opposite side” of the orbit from the time of the observation, and all lining up as seen from Earth. This has also been seen before in previous returns of Comet 67P/C-G.
“We need to do more calculations and modelling, but if our interpretation is correct, then the dust grains forming the neckline in December 2015 were ejected from the comet nucleus around March last year, prior to perihelion,” says Alan.
The dust coma can also be seen all around the comet nucleus, with a peak extending just ahead of the comet, and with a broader tail of smaller dust grains swept out below the neckline.
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The amateur community is also acquiring regular images of the comet.
“Because the large telescopes have nowhere near the time-coverage that the amateur/pro-am community have, it’s fantastic to see the amount of valuable data people are collecting,” adds Alan.
For example, the images shown left were taken by Tony Angel and Caisey Harlingten through a 4” telescope of the Searchlight Observatory Network at the Observatorio Sierra Contraviesa, Spain, on 22 December 2015. The image was made by stacking six images taken with an exposure of 300 seconds each in order to bring out deep details of the faint, extended tail structures.
The image is shown in positive (top) and negative (bottom).
Credits: SON@OSC/T. Angel & C. Harlingten.
 
Astronomer Damian Peach has also been keeping a regular eye on the comet as it moves across the sky. The colour composite below captures the comet between September and November last year, showing the comet’s tail and its fuzzy coma. (Click here for an image taken more recently by Damian, on 18 January.)
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Comet 67P/C-G between September and November 2015 seen in six LRGB images acquired with a 24" CDK telescope with FLI camera by Damian Peach. Each section is composed of 8 x 120 second exposure images. During this time, the tail is estimated to measure around 20–30 arc mins. Credit: D. Peach.
“Collecting data from Earth while Rosetta is flying alongside the comet is providing a unique and complementary dataset that will help both Rosetta mission scientists and ground-based astronomers understand processes relating to the comet’s activity at a range of scales,” says Rosetta project scientist Matt Taylor. “We’re hoping that ground based images will continue to be obtained until later this summer when the comet gets fainter and too close to the Sun in the sky to observe.”
Quelle: ESA
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Update: 4.01.2016
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Comet 67P/Churyumov-Gerasimenko
INSIDE ROSETTA’S COMET
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There are no large caverns inside Comet 67P/Churyumov-Gerasimenko. ESA’s Rosetta mission has made measurements that clearly demonstrate this, solving a long-standing mystery.
Comets are the icy remnants left over from the formation of the planets 4.6 billion years ago. A total of eight comets have now been visited by spacecraft and, thanks to these missions, we have built up a picture of the basic properties of these cosmic time capsules. While some questions have been answered, others have been raised.
Comets are known to be a mixture of dust and ice, and if fully compact, they would be heavier than water. However, previous measurements have shown that some of them have extremely low densities, much lower than that of water ice. The low density implies that comets must be highly porous.
But is the porosity because of huge empty caves in the comet’s interior or it is a more homogeneous low-density structure?
In a new study, published in this week’s issue of the journal Nature, a team led by Martin Pätzold, from Rheinische Institut für Umweltforschung an der Universität zu Köln, Germany, have shown that Comet 67P/Churyumov-Gerasimenko is also a low-density object, but they have also been able to rule out a cavernous interior.
This result is consistent with earlier results from Rosetta’s CONSERT radar experiment showing that the double-lobed comet’s ‘head’ is fairly homogenous on spatial scales of a few tens of metres.
The most reasonable explanation then is that the comet’s porosity must be an intrinsic property of dust particles mixed with the ice that make up the interior. In fact, earlier spacecraft measurements had shown that comet dust is typically not a compacted solid, but rather a ‘fluffy’ aggregate, giving the dust particles high porosity and low density, and Rosetta’s COSIMA and GIADA instruments have shown that the same kinds of dust grains are also found at 67P/Churyumov-Gerasimenko.
Pätzold’s team made their discovery by using the Radio Science Experiment (RSI) to study the way the Rosetta orbiter is pulled by the gravity of the comet, which is generated by its mass.
The effect of the gravity on the movement of Rosetta is measured by changes in the frequency of the spacecraft’s signals when they are received at Earth. It is a manifestation of the Doppler effect, produced whenever there is movement between a source and an observer, and is the same effect that causes emergency vehicle sirens to change pitch as they pass by.
In this case, Rosetta was being pulled by the gravity of the comet, which changed the frequency of the radio link to Earth. ESA’s 35-metre antenna at the New Norcia ground station in Australia is used to communicate with Rosetta during routine operations. The variations in the signals it received were analysed to give a picture of the gravity field across the comet. Large internal caverns would have been noticeable by a tell-tale drop in acceleration.
ESA’s Rosetta mission is the first to perform this difficult measurement for a comet.
“Newton’s law of gravity tells us that the Rosetta spacecraft is basically pulled by everything,” says Martin Pätzold, the principal investigator of the RSI experiment.
“In practical terms, this means that we had to remove the influence of the Sun, all the planets – from giant Jupiter to the dwarf planets – as well as large asteroids in the inner asteroid belt, on Rosetta’s motion, to leave just the influence of the comet. Thankfully, these effects are well understood and this is a standard procedure nowadays for spacecraft operations.”
Next, the pressure of the solar radiation and the comet’s escaping gas tail has to be subtracted. Both of these ‘blow’ the spacecraft off course. In this case, Rosetta’s ROSINA instrument is extremely helpful as it measures the gas that is streaming past the spacecraft. This allowed Pätzold and his colleagues to calculate and remove those effects too.
Whatever motion is left is due to the comet’s mass. For Comet 67P/Churyumov-Gerasimenko, this gives a mass slightly less than 10 billion tonnes. Images from the OSIRIS camera have been used to develop models of the comet’s shape and these give the volume as around 18.7 km3, meaning that the density is 533 kg/m3.
Extracting the details of the interior was only possible through a piece of cosmic good luck.
Given the lack of knowledge of the comet’s activity, a cautious approach trajectory had been designed to ensure the spacecraft's safety. Even in the best scenario, this would bring Rosetta no closer than 10 km.
Unfortunately, prior to 2014, the RSI team predicted that they needed to get closer than 10 km to measure the internal distribution of the comet. This was based on ground-based observations that suggested the comet was round in shape. At 10 km and above, only the total mass would be measurable.
Then the comet’s strange shape was revealed as Rosetta drew nearer. Luckily for RSI, the double-lobed structure meant that the differences in the gravity field would be much more pronounced, and therefore easier to measure from far away.
“We were already seeing variations in the gravity field from 30 km away,” says Pätzold.
When Rosetta did achieve a 10 km orbit, RSI was able to gather detailed measurements. This is what has given them such high confidence in their results, and it could get even better.
In September, Rosetta will be guided to a controlled impact on the surface of the comet. The manoeuvre will provide a unique challenge for the flight dynamics specialists at ESA’s European Space Operations Centre (ESOC) in Darmstadt, Germany. As Rosetta gets nearer and nearer the complex gravity field of the comet will make navigating harder and harder. But for RSI, its measurements will increase in precision. This could allow the team to check for caverns just a few hundred metres across.
Quelle: ESA
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Update: 9.02.2016
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COMETWATCH 28 JANUARY
Today's CometWatch is an image taken with Rosetta's NAVCAM on 28 January 2016, when the spacecraft was 67.6 km from the comet nucleus.
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Lightly enhanced NAVCAM image of Comet 67P/C-G taken on 28 January 2016, 67.6 km from the nucleus. The scale is 5.8 m/pixel and the image measures 5.9 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
With the declining comet activity, Rosetta is now approaching the nucleus of 67P/C-G at distances that were not possible to attain since March 2015. This is granting us a detailed view of the comet's surface, including of some regions on the southern hemisphere that were still experiencing polar winter at the beginning of last year.
In particular, the southern portion of the 'neck' region stands out in today's CometWatch, with a dramatic perspective on the rugged terrains of Sobek. The small lobe, on the left in this orientation, reveals the seemingly flat southern region of Wosret, with hints of Bastet towards the upper edge.
The large lobe, on the right, shows a variety of different terrains: from the smooth portions of Aker and Khepry, visible as a bright swath at the top, through the rougher and boulder-rich portions of Khepry and Anhur at the centre, to a side-on view of Imhotep on the right.
The great diversity of Imhotep is clearly visible in this image, with smooth areas covered in dust, large circular features, terraces and many boulders. Hints of the Ash region can also be seen towards the right edge.
The original 1024 x 1024 image is provided below.
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Quelle: ESA
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Update: 12.02.2016
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EIN ABSCHIED AUF RATEN: TIME TO SAY GOODBYE, PHILAE!
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Die zuletzt andauernde Funkstille hatte es bereits angedeutet: Ein Kontakt mit Lander Philae wird immer unwahrscheinlicher, und die Bedingungen für den Lander auf dem Kometen schlechter. „Die Chancen, dass Philae noch einmal Kontakt zu unserem Team im Lander-Kontrollzentrum des DLR aufnimmt, gehen leider gegen Null, und wir senden auch keine Kommandos mehr – es wäre sehr überraschend, wenn wir jetzt noch ein Signal empfangen würden“, sagt Philae-Projektleiter Dr. Stephan Ulamec vom Deutschen Zentrum für Luft- und Raumfahrt (DLR). Für Philae bedeutet das, dass er zwar sehr wahrscheinlich eisfrei, aber voraussichtlich mit Staub bedeckt an seinem schattigen Platz auf Komet Tschurjumow-Gerassimenko in den ewigen Winterschlaf übergeht und sich in der Kälte nicht mehr einschaltet. Die Sonde Rosetta der europäischen Weltraumorganisation ESA wird hingegen noch bis September 2016 um den Kometen kreisen und weiterhin mit ihren wissenschaftlichen Instrumenten Messungen durchführen. Auch die Kommunikationseinheit auf Rosetta wird noch nicht abgeschaltet – sie wird in den nächsten Monaten solange weiterhin auf Signale des Landers horchen, bis die dafür notwendige Energie nicht mehr zur Verfügung steht.
„Es war eine einzigartige Mission mit Philae – es war nicht nur das erste Mal, dass man jemals mit einem Lander auf einer Kometenoberfläche aufgesetzt hat, wir haben auch faszinierende Daten erhalten, mit denen wir noch viele Jahre arbeiten können“, sagt Prof. Pascale Ehrenfreund, Vorstandsvorsitzende des DLR und beteiligte Wissenschaftlerin an der Mission, „Rosetta und Philae haben gezeigt, auf welch faszinierende Art und Weise die Raumfahrt den menschlichen Horizont erweitern und die Öffentlichkeit Anteil an unserer Forschung nehmen kann.“
Am 12. November 2014 hatte Philae seine spektakuläre Landung vollbracht. Inklusive eines Harpunensystems, das nach der zehnjährigen Reise durch das Weltall nicht mehr funktionierte, mehreren Hüpfern über den Kometen und einem Standort, mit dem niemand im Team gerechnet hatte. Weltweit verfolgten die Menschen, ob die zuvor noch nie versuchte Landung auf einem Kometen glücken würde. Schließlich konnten die Ingenieure und Wissenschaftler des DLR um 18.31 Uhr mitteleuropäischer Zeit verkünden: Philae steht auf dem Kometen Tschurjumow-Gerassimenko, 510 Millionen Kilometer von der Erde entfernt – und kommuniziert mit der Erde. Suchmaschine Google widmete sein Startbild dem Lander und ließ Philae ihrem Schriftzug anstelle des zweiten O seine drei filigranen Beine ausstrecken. Zeitungen von Afrika bis Südamerika, von den USA bis nach Asien und Australien vermeldeten die Nachricht der ersten Kometenlandung, in allen Sprachen bestätigten Sprecher in den Nachrichtensendungen, dass Philae tatsächlich sein Ziel erreicht hätte. Währenddessen arbeitete das Team im Kontrollraum des DLR in Köln rund um die Uhr, um die sorgfältig vorbereiteten Pläne an die neue Situation anzupassen und an dem ungeplanten Standort mit Philae zu arbeiten. „Ich hatte schon mit Interesse gerechnet“, sagt DLR-Projektleiter Dr. Stephan Ulamec. „Aber diese weltweite, riesige und auch andauernde Begeisterung hat mich sehr positiv überrascht.“ 
Winterschlaf bei Tiefsttemperaturen
Mehr als  60 Stunden forschten die Wissenschaftler mit Philaes Instrumenten, nahmen Fotos auf, schnüffelten nach Molekülen oder versuchten, sich in den unerwartet harten Untergrund zu hämmern. Mit seinen aufgeladenen Batterien konnte der Lander auch an seinem nur wenig von der Sonne beschienenen Standort arbeiten. Alle gemessenen Daten konnte Philae sicher zur Erde senden. Nach dem Erreichen des sonnennächsten Punkt am 13. August 2015 verabschieden sich  Komet, Rosetta und Philae nun wieder aus dem Inneren des Planetensystems: „Tschurjumow-Gerassimenko ist inzwischen wieder über 350 Millionen Kilometer von der Sonne entfernt“, erläutert Dr. Ekkehard Kührt, Planetenforscher am DLR und zuständig für den wissenschaftlichen Anteil des DLR an der Mission mit Rosetta und Philae. „In der Kometennacht kann es jetzt bis unter minus 180 Grad Celsius kalt werden. Selbst am Tag bleibt der gesamte Komet nun tiefgefroren.“ Für einen Lander, der auf Temperaturen bis minus 50 Grad Celsius ausgelegt ist, ist dies eine Umgebung, in der er nicht mehr arbeiten kann. Wäre er an seinem ursprünglichen Landeplatz zur Ruhe gekommen und hätte sich dort im Boden verankert, hätte er deutlich mehr Sonne zur Energieversorgung zur Verfügung gehabt, wäre aber voraussichtlich im März 2015 bei der Annäherung an die Sonne überhitzt.
Kontaktschwierigkeiten mit Funkpausen
„Dass Philae sich jetzt sehr wahrscheinlich nicht mehr melden wird, liegt auch daran, dass seine Energie nicht mehr ausreicht und die Elektronik zu kalt ist“, sagt Philae-Projektleiter Dr. Stephan Ulamec. Auch in den letzten Monaten gab es keine Funksignale von Philae. Sein Schweigen im August 2015 hatte jedoch einen anderen Grund: Während des sonnennächsten Punktes befand sich die Rosetta-Sonde in einer zu großen Entfernung, um Signale des Landers empfangen zu können und zur Erde weiterzuleiten. „Es gab im vergangenen Jahr aber auch Zeiten, in den wir nicht verstanden haben, warum Philae keinen Kontakt zu uns aufnimmt.“ Philae meldete sich zwar am 13. Juni 2015 und sendete Daten über seinen Gesundheitszustand. Insgesamt nahm er auch sieben weitere Male Kontakt zum Bodenteam auf – doch blieb dies unregelmäßig und relativ unvorhersagbar. Am 9. Juli 2015 sendete er zum letzten Mal Informationen. „Wir haben immer wieder verschiedene Kommandos gesendet, um den Kontakt mit ihm zu stabilisieren und mit den Instrumenten messen zu können, aber dies ist leider nicht gelungen.“ Die Ingenieure des Projekts  halten es für möglich, dass Kurzschlusse an den Sendern der Grund für die unregelmäßigen Kontakte und das anschließende Schweigen sein könnte.
Positive Bilanz für eine Premiere
Auch wenn die Arbeit mit Philae Wünsche offen gelassen hat – beispielsweise die chemische Untersuchung einer Bodenprobe oder mehr Zeit für wissenschaftliche Messungen: „Solche hochaufgelösten und spektakulären Bilder wie von der ROLIS-Kamera gewonnene, die unterhalb des Landers sitzt, sowie  von der Panoramakamera CIVA werden wir lange Zeit nicht mehr bekommen.“ Außerdem wurden mit einem Massenspektrometer organische Moleküle auf der Oberfläche gefunden und mit der Thermalsonde MUPUS sowie dem Seismometer SESAME physikalische Eigenschaften der Kometenoberfläche bestimmt. Der Kometenkern wurde von Sonde zu Lander mittels Radarstrahlen durchleuchtet, woraus Erkenntnisse über seine Struktur gewonnen werden konnten. Ein messbares Magnetfeld wies der Komet nicht  auf. Viele Ergebnisse wurden inzwischen in  wissenschaftlichen Journalen publiziert. „Die  Auswertung der Daten wird jedoch noch über mehrere Jahre weitergehen“, betont DLR-Planetenforscher Dr. Ekkehard Kührt.
Wissen für zukünftige Missionen
Mit der Rosetta-Mission wurden gleich mehrere Premieren im All gefeiert: Noch nie begleitete eine Raumsonde einen Kometen auf seinem Weg um die Sonne, noch nie landete ein Gerät auf einer Kometenoberfläche, um dort Messungen durchzuführen. „Wenn man einen Vergleich mit anderen historischen Missionen sucht, wären dies vielleicht die Viking-Mission, die zum ersten Mal detaillierte Bilder vom Mars sendete, oder auch die Voyager-Sonden, die einen Blick auf die großen Planeten unseres Sonnensystems ermöglichten“, sagt Philae-Projektleiter Dr. Stephan Ulamec vom DLR. Die Landung mit Philae war zudem auch eine gute Lehrstunde: „Wir können zukünftige Missionen besser an die Bedingungen auf einem Kometen anpassen.“
Die  letzten Fotos von Philae wird es sehr wahrscheinlich im Sommer 2016 geben, wenn die Rosetta-Sonde in nahen Vorbeiflügen auf den Lander blickt. „Wenn wir dann sehen, wie Philae positioniert ist, können wir manche Daten wie die Messungen des Radar-Experiments CONSERT noch besser interpretieren.“ In etwa sechs Jahren werden Philae und die Rosetta-Sonde, die im September 2016 zum Abschluss der Mission auf dem Kometen landen soll, zumindest wieder der Erde nahe sein – dann hat Komet Churyumov-Gerasimenko die Sonne ein weiteres Mal umrundet.
Die Mission
Rosetta ist eine Mission der ESA mit Beiträgen von ihren Mitgliedsstaaten und der NASA. 
Die Mission wird im Europäischen Satellitenkontrollzentrum ESA / ESOC in Darmstadt gesteuert.
Rosettas Lander Philae wird von einem Konsortium unter der Leitung von DLR, MPS, CNES und ASI beigesteuert.
Quelle: ESA
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Update: 5.03.2016
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COMETWATCH – JANUARY PART 2
In this new NAVCAM view, taken 21 January, Comet 67P/Churyumov-Gerasimenko’s small lobe and its distinctive Hatmehit depression face directly towards Rosetta.
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Lightly enhanced Rosetta NAVCAM image taken on 21 January 2016 from a distance of 78.9 km. The scale is 6.7m/pixel and the image measures 6.9 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The Bastet region on the small lobe faces directly up in this orientation, with Ma’at immediately to the left and Wosret to the right. In the background, on the large lobe, a swath of smoother terrain – defining Aker, with Khepry beyond – lies between the more rugged terrain of Babi (left) and Anhur (right).
Parts of these southern hemisphere regions (to the right in the NAVCAM image) were also seen in spectacularly detailed images captured by Rosetta’s OSIRIS narrow-angle camera this week. For example, the image below was taken on 27 January as part of an extensive surface mapping campaign. The complete sequence is aiming for a large coverage of the southern hemisphere to be used for 3D shape reconstruction and composition maps.
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OSIRIS narrow-angle camera image captured on 27 January from a distance of 71.4 km. The image scale is 1.29 m/pixel.
Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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The relatively flat Aker surface can be identified to the right in this image, with Khepry to the top and Anhur towards the foreground. Sobek (centre) marks the transition towards the small lobe (left) where distinctive fracture patterns are clearly seen in Wosret (far left).
As we learned in the original OSIRIS release yesterday, the image also features two regions not previously mentioned before: Neith and Bes. The details of the regions and the locations of the boundaries are still under study (and precisely why images like this are essential), but broadly speaking, Neith lies between Wosret and Sobek on the small lobe, and Bes lies to the right of Anhur and extends into the foreground of this particular image.
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OSIRIS narrow-angle camera image captured on 23 January from a distance of 75.1 km. The image scale is 1.37 m/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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The OSIRIS team also released a striking new view focusing on the Khonsu region this week, at the boundary with Atum and Anubis (above). A variety of fracture-like features and layers are clearly visible. For example, zooming in close to the centre of the image reveals parallel sets of fracture lines that cross perpendicular to each other. On Earth and Mars this is often an indicator of ice that has contracted below the surface (see more examples and further discussion here).
Towards the right, long and near-parallel curvilinear features are evident and can be traced for some distance from the rugged terrain in the foreground to the smoother surface beyond. Understanding how features like these relate to the internal structure of the comet, and thus to the comet’s formation and evolution, is a hot topic for Rosetta mission scientists.
Meanwhile in the background of this image, much of the Anuket region on the comet’s small lobe is seen to the centre and left, with the transition into southern hemisphere regions towards the far right.
Catch up on recent OSIRIS images via the image of the day archive.
For help navigating the regions of the comet, see our comet viewer tool.
The original NAVCAM image from today’s CometWatch is provided below:
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COMETWATCH FEBRUARY – PART 1
This month, Rosetta is approaching Comet 67P/Churyumov-Gerasimenko at 40 km or less, returning beautiful views of the nucleus and its surface features. In today's CometWatch image, we see the comet pictured by Rosetta's NAVCAM on 10 February 2016, when the spacecraft was 50.6 km from the comet nucleus.
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Lightly enhanced NAVCAM image of Comet 67P/C-G taken on 10 February 2016, 50.6 km from the nucleus. The scale is 4.3 m/pixel and the image measures 4.4 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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In this orientation, the small comet lobe is in the foreground, towards the top left of the frame, and the large lobe is farther away, in the lower-right part of the image. The view reveals most of the comet's southern hemisphere, which has been experience a short and intense summer since May 2015.
The illuminated portion of the large lobe is dominated by the southern region of Anhur, with hints of Sobek on the neck. Smooth portions of Aker and Khepry are also visible towards the upper edge.
A number of regions are depicted in this view of the small lobe: Maftet, Nut and Serqet towards the lower left, Bastet on the upper right edge of the lobe, but most notably the vast, round cavity of Hatmehit in the top left and the seemingly flat terrains of Wosret at the centre of the image.
The contrast between Hatmehit, covered in dust and boulders, and the rough features on the neighbouring Wosret region were also captured in another striking image, taken with the narrow-angle camera of Rosetta's OSIRIS imaging system on 13 February somewhat closer to the comet, at 45.8 km.
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OSIRIS narrow-angle camera image taken on 13 February 2016, when Rosetta was 45.8 km from the comet. The scale is 0.82 m/pixel and the image measures 1.7 km across. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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The OSIRIS image provides a zoomed-in, detailed view onto this portion of the comet as seen in the NAVCAM image, although with a slightly different viewing angle, revealing a great deal of details about these two regions. A portion of Bastet is also visible in the OSIRIS image, including the brighter slab on the top edge of the lobe.
The original NAVCAM image is provided below.
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COMETWATCH FEBRUARY – PART 2
This week’s CometWatch entry pictures Comet 67P/C-G as seen with Rosetta’s NAVCAM on 22 February, from a distance of 32.5 km to the centre of the comet.
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Enhanced NAVCAM image of Comet 67P/C-G taken on 22 February 2016, 32.5 km from the nucleus. The scale is 2.8 m/pixel and the image measures 2.8 km across. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
At this close distance the comet nucleus overfills the camera’s field of view, but allows details of the surface to be seen at closer range than in previous weeks and months. This image focuses on the comet’s ‘neck’ region and the transition of smooth Hapi (centre) into Anuket to the left, and Seth on the large lobe to the right. Serqet is seen to the top left of the frame.
Furthermore, the composition of this image is such that traces of the comet’s activity are revealed, emanating from around the neck region and extending towards the top right of the frame.
This is nicely complemented by a wide-angle view taken by Rosetta’s OSIRIS wide-angle camera last week – and released today via the OSIRIS image of the day website – showing the current state of the comet’s activity all around the nucleus (below).
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Comet 67P/C-G taken on 18 February by Rosetta’s OSIRIS wide-angle camera from a distance of about 35.6 km. The image scale is 3.45 m/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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Meanwhile the OSIRIS narrow-angle camera continues to capture ever-detailed views of the surface in high resolution. The image below was taken on 13 February and also released via the OSIRIS image of the day website this week.
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Comet 67P/C-G taken on 13 February by Rosetta’s OSIRIS narrow-angle camera from a distance of about 46 km. The image scale is 0.84 m/pixel. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
The scene captures a detailed look at part of the Aker (foreground) and Khepry (background) regions, and extends into Babi towards the left of the image.
The original NAVCAM image for today's CometWatch entry is provided below:
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Quelle: ESA

Tags: Raumfahrt 

1610 Views

Samstag, 5. März 2016 - 15:45 Uhr

Astronomie - Hubble und ein Sternen Fingerabdruck

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Showcased at the center of this NASA/ESA Hubble Space Telescope image is an emission-line star known as IRAS 12196-6300.
Located just under 2,300 light-years from Earth, this star displays prominent emission lines, meaning that the star’s light, dispersed into a spectrum, shows up as a rainbow of colors marked with a characteristic pattern of dark and bright lines. The characteristics of these lines, when compared to the “fingerprints” left by particular atoms and molecules, can be used to reveal IRAS 12196-6300’s chemical composition.
Under 10 million years old and not yet burning hydrogen at its core, unlike the sun, this star is still in its infancy. Further evidence of IRAS 12196-6300’s youth is provided by the presence of reflection nebulae. These hazy clouds, pictured floating above and below IRAS 12196-6300, are created when light from a star reflects off a high concentration of nearby dust, such as the dusty material still remaining from IRAS 12196-6300’s formation.
Quelle: NASA

Tags: Astronomie 

1591 Views

Samstag, 5. März 2016 - 15:30 Uhr

Raumfahrt - Scott Kelly: Sechs Dinge, die passieren, nach einem Jahr im Weltraum

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After a record stay in space, astronaut Scott Kelly grew 1.5 inches due to a lack of gravity. He faces a greater risk of cancer than most earth-bound folks due to radiation exposure that’s 20 times higher in space. His bones are less dense than they used to be, and his heart is likely smaller.
“It felt like I had been up there my whole life, you know, after about the first six months,” Kelly said in a NASA video following his March 1 return from the International Space Station. “I’m definitely encouraged on our ability to go even longer.”
Kelly spent 340 days aboard the ISS on his fourth mission to space, along with Russian cosmonaut Mikhail Kornienko. Over his entire career, Kelly has spent 520 days in space. His twin brother, retired astronaut Mark Kelly, is providing data to help quantify the effect of a year in space on a person who is almost identical genetically.
Humans aren’t engineered for long-term space travel, which makes Kelly’s Year in Space mission a key component of NASA’s efforts to mitigate the harsh effects. If it doesn’t succeed, missions to Mars and any plans for supply or mining operations on the moon won’t be feasible. A round trip to Mars is expected to last more than 500 days.
Here are some of the things that happen to the body in space, which NASA needs to understand better:
The fluids in your body shift due to zero gravity. In the brain, this can cause impaired vision or even loss of sight, a problem NASA astronauts detected only in recent years as ISS stays became longer. Scott Kelly also had some vision issues. “He’s just starting to get an idea of the impact on his vision,” Mark Kelly said Friday at a NASA news conference. The fluid movement can alter eye shapes. The working theory is that genetics and a lack of certain B vitamins disposes some people to have this vision problem in zero gravity.
Some bones, muscles, and organs deteriorate. Astronauts can lose as much as 2 percent of their bone density each month, according to NASA, more than twice the amount the average adult loses annually. This is because of the lack of weight bones experience in space and differences in how the body processes calcium. Muscle soreness is a common complaint among space travelers. “Which muscles or muscle groups hurt?” a reporter asked Scott Kelly Friday. “Yeah, all of them,” he replied. The zero-G environment can also cause increased risk of kidney stones, hip and spine troubles, and slower healing times. A decrease in the size of the heart is related to changes in blood flows, but the issue still isn't well understood. To counteract some of these effects, astronauts on the ISS exercise frequently and vigorously. 
You get taller: Gravity on earth compresses our spine, which doesn’t happen in space, as fluids flow between the spinal disks. But the effect isn’t permanent. Back on earth, you revert rapidly to your original height.
Immunity is suppressed: The human immune system doesn’t operate as well in space, and NASA isn’t sure why. 
Space is a cancer danger. Astronauts are exposed to far more radiation than people on earth because of the shielding effect of the planet's atmosphere. NASA rigorously monitors astronauts’ career radiation levels—which means Kelly almost certainly has no future space time—but a long mission will require advanced work on how to mitigate this risk.
The isolation carries psychological effects, among the most significant and most mysterious aspects of long periods in space. Understanding and ameliorating the psychological effects of extended missions will be critical to any future human exploration of space, because NASA expects these impacts will be larger as mission lengths increase. 
Quelle: Bloomberg

Tags: Raumfahrt die passieren 

1515 Views

Samstag, 5. März 2016 - 15:00 Uhr

Raumfahrt - Erfolgreicher Start von SpaceX Falcon9 mit SES-9 Satelliten

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8.02.2016

SES said that it is targeting a February 24, 2016 launch date (with a backup date of the 25th) for its new satellite, SES-9.
This date was mutually set by SES and the launch operator for SES-9, SpaceX, the Hawthorne, California based company that designs, manufactures and launches the Falcon 9 rocket and other spacecraft. SpaceX is currently completing an extended series of testing and pre-flight validation in advance of the SES-9 launch, which will take place at Cape Canaveral Air Force Station, Florida.
In order to minimise the impact of moving the launch from late last year, SpaceX is supporting a mission modification. The changed mission will reduce the time needed for SES-9 to reach its orbital slot, keeping the Operational Service Date (OSD) in the third quarter of 2016, as previously foreseen.
SES-9 will be positioned at 108.2 degrees East and provide both replacement and incremental capacity for a prime video neighbourhood over Asia which already serves over 22 million households with high quality broadcast solutions. The spacecraft will be co-located with SES-7 and increases SES’s global video capabilities to serve markets in Asia, including South Asia, Indonesia and the Philippines.
The spacecraft is also designed to deliver data connectivity to homes and enterprises across Asia, and provides dedicated beams to support growing mobility communications needs across the Indian Ocean.
SES-9 is part of a fleet investment programme that supports SES`s strategy to further globalise its services and grow its offer in the dynamic emerging markets. Along with six other spacecraft under construction, this programme will increase SES´s satellite capacity for emerging markets by 21% by end of 2018.
SES-9 was built by Boeing Satellite Systems and is designed to operate for 15 years in geosynchronous orbit with a 12.7-kilowatt payload and 57 high-power Ku-band transponders (equivalent to 81 × 36 MHz transponders).
SES-9 will use a chemical bi-propellant apogee motor to quickly achieve a 24h synchronous orbit and then electric propulsion to circularise the final orbit and to remove eccentricity at 36,000 kilometers over the equator. Subsequent on-orbit manoeuvres will be executed with electric propulsion.
Quelle: Broadband TV News
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Update: 23.02.2016
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SpaceX Falcon 9 conducts Static Fire ahead of SES-9 launch

SpaceX’s Falcon 9 rocket has conducted her Static Fire test on Monday, a dress rehearsal milestone ahead of Wednesday’s launch of the SES-9 satellite. The test took place at SLC-40, at the same time as work begins at LC-39A to remove the Shuttle-era Rotating Service Structure (RSS) from the site of future SpaceX launches.
SES-9:
The Static Fire test validates the health of the launch vehicle, allowing for SpaceX management to approve the final flow to launch day.
Numerous requirements have to be successfully proven via such a test, such as the engine ignition and shut down commands, which have to operate as designed, and that the Merlin 1D engines perform properly during start-up.
It also serves as a full dress rehearsal for the launch team and provides another test of SpaceX’s recent upgrade to a supercooled propellant pad systems that resulted in a number of challenges ahead of its debut use during the OG-2 launch.
The Falcon 9 was erected vertical at the pad around 1pm Eastern, ahead of the Static Fire test around 5:50pm Eastern.
Once the required engine and vehicle data has been collected detanking operations will follow, before the rocket is lowered onto the Transporter Erector (TE) and rolled back to the hanger.
The Static Fire’s data review will be fed into the Launch Readiness Review (LRR) – a key meeting that will ultimately confirm the launch date.
The first attempt is currently scheduled for Wednesday, within a window that ranges from 18:46 to 20:23 Eastern. A second opportunity is available on Thursday, within the same launch window.
The mission is tasked with lofting the SES-9 spacecraft en route to its orbital slot of 108.2° E. This satellite has been patiently waiting its turn for a ride into space after it was initially set to ride as the Return To Flight mission last year.
The satellite will provide incremental – as well as replacement capacity – to the well-established slot over Asia, where it will be co-located with the existing satellites.
Built by Boeing, the spacecraft is based on the BSS-702HP bus and has a launch mass of 5,330 kg.
With 81 (36 MHz equivalent) Ku-band transponders, the satellite will expand SES’s capability to provide DTH broadcasting and other communications services in Northeast Asia, South Asia & Indonesia, as well as maritime communications for vessels in the Indian Ocean.
It is set for a service life of 15 years.
Despite this mission being a demanding Geostationary Transfer Orbit (GTO) launch, SpaceX still hopes to return the first stage back to the recently deployed Autonomous Spaceport Drone Ship (ASDS) landing barge, named “Of Course I Still Love You”.
Nailing a landing on the ASDS in the Atlantic is technically more of a challenge than returning to Landing Zone 1 (LZ-1) at Cape Canaveral.
The successful landing of the OG-2 first stage at LZ-1 was the first successful recovery of a flown Falcon 9 stage, which was followed up with a successful two second static fire test at SLC-40.
The stage is currently housed at the new HIF at 39A, albeit now with its aft end somewhat dismantled for inspections along with – according to sources – some “potential” harvesting for future vehicles – which would play into the goal of initial reusability of flown hardware.
The stage itself will not fly again, per comments previously made by SpaceX CEO Elon Musk. The first “reflight” of a recovered stage may come late this year, based on upcoming recoveries.
Numerous brand new Falcon 9’s are currently in various stages of production on the Hawthorne factory floor, as recently shown in a SpaceX photo.
The company did not reveal which stages relate to which specific future missions – although the upcoming CRS-8 first stage was still at the McGregor test site, several days after a test incident resulted in damage to the hardware.
It is likely all the stages in the photo are destined to be part of Falcon 9’s busy 2016 Q2/Q3 schedule, while the debut of the Falcon Heavy – and its three cores – is, at least, half a year away.
Falcon Heavy will be the first rocket to launch from SpaceX’s 39A pad at the Kennedy Space Center, a pad that has been converted from its Shuttle era to being able to launch both the Falcon Heavy and Falcon 9.
One of the final phases of its conversion is about to begin, with a huge crane now on site at the pad, ready to remove the Rotating Service Structure (RSS).
The RSS was used to install payloads into the Shuttle’s payload bay, whilst providing protection to the orbiter during her pad stay.
2016-02-22-033122Once the RSS is removed, the remaining Fixed Service Structure (FSS) will undergo some structural reinforcements, according to SpaceX.
The FSS – just as it did during the Shuttle and Apollo era – will be the final leg for astronauts ready to ingress the spacecraft ahead of launch. This time, the astronauts will be boarding the Dragon 2 spacecraft, sometime in 2017.
The mission, called “SpX-DM2″ – will be the second flight of the Dragon 2 spacecraft to the International Space Station, following on from the December 2016 “SpX-DM1″ flight, which is set to be an uncrewed demonstration mission.
Quelle: NS
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Update: 22.10 MEZ
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Update: 24.02.2016 /11.50 MEZ
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Date
Thu, Feb 25 2016 12:46 AM CET — Thu, Feb 25 2016 3:00 AM CET
About
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SpaceX’s Falcon 9 rocket will deliver SES-9, a commercial communications satellite for SES, to a Geostationary Transfer Orbit (GTO). SES is a world-leading satellite operator that provides satellite-enabled communications services to broadcasters, Internet service providers, mobile and fixed network operators, and business and governmental organizations worldwide using its fleet of more than 50 geostationary satellites. SpaceX is targeting an evening launch of SES-9 from Space Launch Complex 40 at Cape Canaveral Air Force Station, Fla. The approximately 90-minute launch window opens on February 24 at 6:46:14 pm ET. A backup launch window opens at 6:46:17 pm ET on February 25. The satellite will be deployed approximately 31 minutes after liftoff.
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Quelle: SpaceX
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Update: 25.02.2016
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Start wegen Wetter um 24 Stunden verschoben:
Quelle: SpaceX
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Update: 22.00 MEZ
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Update: 26.02.2016:
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Weather for today's launch attempt at 80% favorable, though upper level winds and ground level winds remain watch items.
Quelle: SpaceX
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SpaceX scrubbed its second attempt at launching a satellite on Thursday.
Just under two minutes away from the private space company's scheduled launch time, the countdown froze. A new launch day has not yet been set.
The mission, which SpaceX is carrying out on behalf of SES, could provide internet access to remote areas of the Asia-Pacific, including India, where about 1 billion people have no internet access.
The first launch attempt from the Cape Canaveral Air Force Station in Florida on Wednesday was aborted "out of an abundance of caution" because the SpaceX team was still working to "ensure liquid oxygen temperatures are as cold as possible," the company said. The colder the liquid oxygen, the more powerful the thrust.
The reason for aborting the second launch attempt on Thursday was not immediately clear.
But liquid oxygen -- which is a key rocket fuel ingredient -- was a key reason SpaceX could not reattempt the launch Thursday night.
Related: SpaceX rocket explodes after landing
Nearly all of the fuel had been loaded from the holding tank and into SpaceX's Falcon 9 rocket when the launch was halted, so the rocket will need to be emptied.
Oxygen has to be kept at -297˚F in order to remain liquid, and Musk wants to use even colder oxygen because it offers a more powerful launch.
SpaceX didn't indicate what the target temperature is for this mission, but Musk said he wanted the liquid oxygen at -340˚F for a rocket that took off on a December mission.
Quelle: CNN
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Update: 19.30 MEZ
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Update: 28.02.2016 / 19.20 MEZ
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...22.20 MEZ
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Update: 29.02.2016
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Third try for SpaceX launch aborts
CAPE CANAVERAL - The third try for a SpaceX launch aborted again just before takeoff Sunday.
The launch for a communications satellite was set for 6:47 p.m today at Cape Canaveral.
The launch held on the pad briefly at one point becuase a boat got in the way, but that problem cleared just before the launch restarted. The abort signal was then given just as the countdown reached zero. 
A tweet from the Air Force's 45th Space Wing indicated that the next launch date would likely not be until Tuesday or later.
SpaceX tweeted Sunday afternoon that the launch was on, although the company was monitoring high-level winds.
Launches for the same rocket and satellite were scrubbed on Wednesday and Thursday. Thursday's countdown was aborted at 6:45 p.m., two minutes before liftoff, according to SpaceX's online webcast. The launch is also supposed to feature another attempt at landing the reusable Falcon 9 rocket on a barge.
During a countdown halt, sometimes there is no more time to reload propellant again, which is what SpaceX personnel said on a webcast about Thursday's launch.
The commercial space company said Wednesday's scrub was "out of an abundance of caution," but that the Falcon 9 rocket "remains healthy."
The launch will be SpaceX's first this year from Florida's Space Coast.
The rocket is to carry a satellite for Luxembourg-based SES into orbit that will help telecommunications and broadcasts in Asia.
The company will also attempt to land the rocket after it delivers its payload on an ocean barge for the first time, a move some say will help the company as it progresses toward a mission to Mars.
Industry experts said the landing would cut costs for the company, resulting in a smaller financial threshold for launching payloads into space.
SES has more than 50 satellites already in orbit and the launch of SES-9 will expand its capacity, company officials said.
Experts had said the variables of a barge landing, including precise location and speed of descent, made it much tougher than doing so on land, which the company has already done.
Quelle: Orlando Sentinel
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Update: 1.03.2016
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Update: 2.03.2016
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Launch update
Unfortunately upper-level winds continue to exceed acceptable limits and are expected to get worse as we approach tonight’s launch window, so we are forgoing today’s launch attempt. Winds are forecast to exceed acceptable limits through Thursday. Our team will continue working with the Air Force’s Launch Weather Officer to evaluate the best available opportunity for flight in the coming days.
Quelle: SpaceX
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Update: 3.03.2016
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'Sledgehammer' winds have led SpaceX to reschedule its launch for Friday
Due to high altitude winds, Elon Musk has announced that SpaceX will postpone its second launch of the year for this Friday.
"Pushing launch to Friday due to extreme high altitude wind shear. Hits like a sledgehammer when going up supersonic," Musk Tweeted.
This is the fourth time in one week — since last Wednesday — that SpaceX has postponed its mission to launch the Boeing-made SES-9 satellite into space.
SpaceX's spokesperson Phillip Larson added in an email statement:
"Winds are forecast to exceed acceptable limits through Thursday. Our team will continue working with the Air Force’s Launch Weather Officer to evaluate the best available opportunity for flight in the coming days.” 
Cancellations aren't necessarily a sign that anything is wrong. And as of Sunday, the Falcon 9 rocket prepped for the mission was reportedly in good health.
SpaceX is simply being extra careful to make sure everything goes smoothly once the rocket lifts off the ground.
The reason this launch has garnered such attention is because of an attempted rocket landing that will swiftly follow take-off.
SpaceX has been trying for over a year now to land the first stage of its Falcon 9 rockets onto an ocean platform. The attempt scheduled to take place after Friday's launch will be SpaceX's fourth try for success.
Despite the fact that SpaceX has stated that it has low expectations of success, these rocket landings are a novelty of 21st century spaceflight and worth getting excited about.
Quelle: BI
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Update: 4.03.2016
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SpaceX to try again Friday for Falcon 9 launch
SpaceX plans to try again Friday to launch its Falcon 9 rocket from Cape Canaveral after scrubbing three launches recently because of weather and a pesky boat that wandered into an off-limits zone.
The launch window Friday is set to open at 6:35 p.m. and close at 8:06 p.m.
The last launch attempt Sunday was in the final countdown stages twice when it was aborted. Earlier this week, a launch update said that upper-level winds continued to exceed acceptable limits and were expected to stay that way through tonight.
A nighttime launch should be visible from South Florida. The webcast will also be available live at www.spacex.com/webcast. 
Quelle: SpaceX
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Update: 5.03.2016 / 8.25 MEZ
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Erfolgreicher Start von Falcon-9 mit SES-9 Satelliten
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Quelle: SpaceX
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Update: 15.00 MEZ
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TV broadcasting satellite finally launched on Falcon 9

Quelle: SpaceX

Tags: Raumfahrt 

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Samstag, 5. März 2016 - 14:45 Uhr

Astronomie - Leben oder Illusion? Die Vermeidung von "falschen Positiven" bei der Suche nach Lebenswelten

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New research from the University of Washington-based Virtual Planetary Laboratory will help astronomers better identify and rule out “false positives” in the ongoing search for life. Shown is a NASA illustration of Kepler 62E, about 1,200 light-years away in the constellation Lyra.NASA

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Is it life, or merely the illusion of life?
Research from the University of Washington-based Virtual Planetary Laboratory published Feb. 26 in Astrophysical Journal Letters will help astronomers better identify — and thus rule out — “false positives” in the search for life beyond Earth.
Powerful devices such as the James Webb Space Telescope, set for launch in 2018, may help astronomers look for life on a handful of faraway worlds by searching for, among other things, evidence of oxygen — a “biosignature” — in their atmospheres. This is done by transit spectroscopy, or studying the spectral features of light visible through a planet’s atmosphere when it transits or passes in front of its host star.
“We wanted to determine if there was something we could observe that gave away these ‘false positive’ cases among exoplanets,” said lead author Edward Schwieterman, a doctoral student in astronomy. “We call them ‘biosignature impostors’ in the paper.
“The potential discovery of life beyond our solar system is of such a huge magnitude and consequence, we really need to be sure we’ve got it right — that when we interpret the light from these exoplanets we know exactly what we’re looking for, and what could fool us.”
Here on Earth, oxygen is produced almost exclusively by photosynthesis — plants and algae converting the sun’s rays into energy to sustain life. And so Earth’s oxygen biosignature is indeed evidence of life. But that may not be universally true.
Previous research from the Virtual Planetary Laboratory has found that some worlds can create oxygen “abiotically,” or by nonliving means. This is more likely in the case of planets orbiting low-mass stars, which are smaller and dimmer than our sun and the most common in the universe.
The first abiotic method they identified results when the star’s ultraviolet light splits apart carbon dioxide (CO2) molecules, freeing some of the oxygen atoms to form into O2, the kind of oxygen present in Earth’s atmosphere.
The giveaway that this particular oxygen biosignature might not indicate life came when the researchers, through computer modeling, found that the process produces not only oxygen but also significant and potentially detectable amounts of carbon monoxide. “So if we saw carbon dioxide and carbon monoxide together in the atmosphere of a rocky planet, we would know to be very suspicious that future oxygen detections would mean life,” Schwieterman said.
The team also found an indicator for abiotic oxygen resulting from starlight similarly breaking down atmospheric water, H2O, allowing hydrogen to escape and leaving vast quantities of oxygen — far more than the Earth has ever had in its atmosphere.
In such cases, Schwieterman said, oxygen molecules collide with each other frequently, producing short-lived pairs of oxygen molecules that become O4 molecules, with their own unique signature.
“Certain O4 features are potentially detectable in transit spectroscopy, and many more could be seen in reflected light,” Schwieterman said. “Seeing a large O4 signature could tip you off that this atmosphere has far too much oxygen to be biologically produced.”
“With these strategies in hand, we can more quickly move on to more promising targets that may have true oxygen biosignatures,” he said.
“It’s one thing to detect a biosignature gas, but another thing to be able to interpret what you are looking at, said Victoria Meadows, UW professor of astronomy and principal investigator of the Virtual Planetary Laboratory. “This research is important because biosignature impostors may be more common for planets orbiting low-mass stars, which will be the first places we look for life outside our solar system in the coming decade.”
Schwieterman’s other UW co-authors are astronomy professor Rory Barnes and doctoral students Giada Arney and Rodrigo Luger.
Other co-authors are Shawn Domagal-Goldman of the NASA Goddard Space Flight Center in Greenbelt, Maryland; Drake Deming of the University of Maryland; and Chester Harman of Pennsylvania State’s Center for Exoplanets and Habitable Worlds.
The research was funded by the NASA Astrobiology Institute.
Quelle: University of Washington

Tags: Astronomie 

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