Sonntag, 14. Juni 2015 - 14:00 Uhr

Raumfahrt - ESA-Sonde Rosetta/Philae auf Komet 67P/Churyumov-Gerasimenko - Update-24



The SONC prepares the wake of Philae
The fourth period of attempts to contact Philae may be good, believe Cédric Delmas, responsible for the operations SONC and Eric Jurado, responsible for activities in space mechanics SONC. They return to activities at the Science Operation Center & Navigation CNES in Toulouse to prepare this revival.
Eric Jurado, responsible for activities in space mechanics SONC, and Cedric Delmas, responsible for the SONC operations. Credits: CNES / E. Grimault, 2014.
More than seven months after the landing of Philae on the core of Comet 67P / Churyumov-Gerasimenko, the activity is still intense in SONC (Science & Navigation Operation Center) installed in the building Descartes CNES in Toulouse, and space mechanics team is heavily involved in attempts to repeatedly contact Philae?
Cédric Delmas: "Sure. The space mechanics SONC team determines the best times to that Rosetta is trying to pick up the signal of Philae. In better times, means the period during which the orbiter is in the field of view of Philae antennas when the solar panels of the landing gear are most likely illuminated by the Sun and that it should have sufficient energy to communicate. "
But is there not a problem of distance between Rosetta and Philae?
Eric Jurado: "Following the recent problems navigation by the orbiter, it was a bit far from the core to protect it from the effects of the increasing activity at the approach of the Sun, but we are still largely in the limited in terms of distance. In fact, if the communication is obviously a bit more difficult between the orbiter and Philae when it moves away, it is still possible to over 200 km. "
Cédric Delmas: "We have made calculations that show that Philae could even communicate with Rosetta 400 km of distance; the only consequence would be the duration of effective communication that would be much shorter at each window. "
Hence the importance of knowing the orientation of Philae to the ground to determine with the greatest possible precision potential niche communications?
Eric Jurado: "Yes, but of course we are taking margins, we do not try to communicate only during those moments, we cover broader periods. "
How many he has had communication attempts periods between the orbiter and Philae?
Cédric Delmas: "We are in 3 periods of communications attempts. One in March, one in April and the third period ended May 20 We have a new program period that will begin in the coming days, May 30 normally. There has been no contact so far and I can say that we expected a bit for the first 2 periods that came very early compared to the possibilities of revival of Philae. Now the conditions seem more favorable so we think that a resumption of contact for this. "
Eric Jurado with several members of the space mechanics team SONC. Credits: CNES / G. Cannat, 2014.
This awakening of Philae dependent on its precise position on the nucleus and its orientation, have you made progress on these points?
Eric Jurado: "What we can say today is that, thanks to CONSERT data and OSIRIS ROMAP mainly, but also thanks to the information provided by CIVA ROMAP and ROLIS and enlightenment solar panels we know with an accuracy of less than 50 m the final landing point of Philae. We also know how the undercarriage is oriented relative to the surface. "
SONC of the teams they will do a scientific publication on the analysis of how the landing took place?
Eric Jurado: "We are currently conducting any work that will be useful to all scientists: it is a study on how Philae came down, he bounced back and how he finally landed, because scientists really need these data to better interpret measurements of their instruments. There has already had publications in technical journals and there will be an article soon in Science for which we are co-authors. "
Attention has focused on the many non-functioning harpoons and cold gas thruster during landing, causing multiple rebounds, but the precision obtained in the calculation of the trajectory by the team Space mechanics SONC was truly outstanding?
Eric Jurado: "Philae fell to around 120 m from the place in question and with less than a minute offset relative to the calculated trajectory, which is really good compared to what we expected. "
Cédric Delmas: "Remember, the ellipse of uncertainty for the landing was a major axis of about 800 m, so we were practically in the center! "
Cédric Delmas, responsible for operations of SONC, Science & Navigation Operation Center, CNES in Toulouse. Credits: CNES / E. Grimault, 2014.
If the contact is restored with Philae in the days or weeks, the SONC will again be first in line to manage the planning of scientific activities?
Cédric Delmas: "The teams SONC mobilized for months to redefine all the activities that could be done immediately after Philae will wake up. We must be prepared to send sequences of use of different scientific instruments as soon as possible. At present, we have established different scenarios to accommodate the environment Philae, its illumination, the energy level available to it, etc. The vast difference from what we had imagined before landing, is that we do not charge the battery, which would have allowed us to establish programs on the longer term. But we know that if Philae does not communicate, it is most likely because the solar panels do not provide enough electrical power for the battery can recharge. We are therefore preparing to work only during the local day, using solar energy directly, bypassing a storage phase. This is a mode of operation that we had not anticipated before landing and had to redefine all scientific activities taking into account these new constraints. "
So, do the instruments will be favored?
Cédric Delmas: "We are to redraw the sequences of use of instruments and we think the conditions deployments. If we wanted to use some instruments, such as APXS, we should first maneuver the body of Philae, bring it down closer to the surface. Similarly, for drilling with drill SD2, since it seems that one has "drilled into the void" in November, it would rotate the balcony of Philae. All this must be carefully studied to establish an order of priority. The idea is to do well at first activities that consume little power, like those of ROMAP or SESAME, and remake images with CIVA and ROLIS to study the immediate surroundings of Philae more accurately under a better lighting. In a second time, then we would consider moving on to more complex activities that implement mechanical elements with the risk of displacement of Philae to be taken into account. "
Quelle: CNES
Update: 2.06.2015
This image of Comet 67P/Churyumov-Gerasimenko was taken by Rosetta's NAVCAM on 20 May at a distance of 163.6 km from the comet centre. It is a single frame image with a resolution of 13.9 m/pixel, and measures 14.3 km across. The intensities and contrast have been adjusted to emphasise the activity of the comet.
Processed image of Comet 67P/C-G taken by Rosetta's NAVCAM on 20 May 2015. Credits: ESA/Rosetta/NavCam – CC BY-SA IGO 3.0
In this orientation, perhaps the most striking observation is the activity seen close to Hatmehit, the circular depression on the comet’s small lobe. There also appears to be activity associated with the Nut region, which lies below Serqet in this orientation. In both cases, the activity stands out against the shadowed portions of the comet in this area.
On the large lobe, the comet is oriented with the relatively smooth face of Anubis towards the top left, making a distinct boundary with the neighbouring rugged Seth region to the right.
In this view the comet also shows off the transition between the two lobes, with Anuket on the small lobe merging into Hapi at the neck.
The original 1024 x 1024 pixel image is provided below:
Quelle: ESA
Update: 3.06.2015
Alice instrument’s ultraviolet close-up provides a surprising discovery about comet’s atmosphere 
SwRI-developed ultraviolet spectrograph is aboard Rosetta, the first spacecraft to study a comet up close
Image Courtesy of Southwest Research Institute
NASA's Alice ultraviolet (UV) spectrograph, seen here during construction, is aboard the European Space Agency's Rosetta spacecraft.
A close-up of Comet 67P/Churyumov-Gerasimenko by NASA’s ultraviolet instrument surprised scientists by revealing that electrons close to the comet’s surface ─ not photons from the Sun as had been believed ─ cause the rapid breakup of water and carbon dioxide molecules spewing from the surface.
Since last August, the European Space Agency’s Rosetta spacecraft has orbited within a hundred miles of the comet in this historic mission. The spectrograph onboard, named Alice, specializes in the far-ultraviolet wavelength band and was developed by Southwest Research Institute (SwRI). Alice examines light the comet is emitting to understand the chemistry of the comet’s atmosphere, or coma. A spectrograph is a tool astronomers use to split light into its various colors. Scientists can identify the chemical composition of gases by examining their light spectrum. Alice is the first such far-ultraviolet spectrograph to operate at a comet.
“The discovery we’re reporting is quite unexpected,” said Alice instrument Principal Investigator Dr. Alan Stern, an associate vice president in SwRI’s Space Science and Engineering Division. “It shows us the value of going to comets to observe them up close, since this discovery simply could not have been made from Earth or Earth's orbit with any existing or planned observatory. And, it is fundamentally transforming our knowledge of comets.”
“Analysis of the relative intensities of observed atomic emissions allows us to determine that we are directly observing the ‘parent’ molecules that are being broken up by electrons in the immediate vicinity, about 1 kilometer, of the comet’s surface from which the parent molecules are vaporizing,” said Dr. Paul Feldman, professor of physics and astronomy at the Johns Hopkins University in Baltimore, Maryland.
Feldman is lead author of the paper, “Measurements of the Near-nucleus Coma of Comet 67P/Churyumov-Gerasimenko with the Alice Far-ultraviolet Spectrograph on Rosetta,” which has been accepted for publication in the journal, Astronomy and Astrophysics.
Much of the water and carbon dioxide originates from “plumes” erupting from the comet’s surface, similar to those that the Hubble Space Telescope discovered on Jupiter’s moon Europa, noted co-author Dr. Joel Parker, an assistant director in SwRI’s Space Science and Engineering Division’s Boulder, Colo., office.
Based on the new Alice data reported in the paper, the explanation for the breakup of those molecules is similar to that for the plumes on Europa, except that the electrons at the comet are produced by solar radiation, while the electrons at Europa come from Jupiter’s magnetosphere, Feldman said.
Parker added, “By looking at the emission from hydrogen and oxygen atoms broken from the water molecules, we also can actually trace the location and structure of water plumes from the surface of the comet.”
The far-ultraviolet region of the spectrum allows scientists to detect the most abundant elements in the universe: hydrogen, oxygen, carbon and nitrogen. However, Feldman noted such measurements must be made from outside the Earth’s atmosphere, either from orbiting observatories such as the Hubble Space Telescope, or from planetary missions such as Rosetta. From Earth's orbit, the atomic constituents can only be seen after their “parent” molecules, such as water and carbon dioxide, have been broken up by sunlight, hundreds to thousands of kilometers away from the nucleus of the comet.
The Alice spectrograph aboard Rosetta has also studied the surface of Comet 67P/ Churyumov–Gerasimenko and will be used in further studies of its atmosphere as the comet approaches the Sun and its plumes become more active due to solar heating.
Rosetta-Alice is one of two ultraviolet spectrographs named “Alice” currently flying in space. The other is New Horizons-Alice. Rosetta-Alice is operated by SwRI under contract with the Jet Propulsion Laboratory/California Institute of Technology for the National Aeronautics and Space Administration. Alice is studying the coma and surface of Comet 67P/Churyumov–Gerasimenko to understand the formation and evolution of comets and the nature of cometary activity and to connect activity of the nucleus with changes in the coma and tail as well as interactions with the solar wind.
Quelle: Southwest Research Institute
Rosetta’s continued close study of Comet 67P/Churyumov–Gerasimenko has revealed an unexpected process at work, causing the rapid breakup of water and carbon dioxide molecules spewing from the comet’s surface.
ESA’s Rosetta mission arrived at the comet in August last year. Since then, it has been orbiting or flying past the comet at distances from as far as several hundred kilometres down to as little as 8 km. While doing so, it has been collecting data on every aspect of the comet’s environment with its suite of 11 science instruments.
One instrument, the Alice spectrograph provided by NASA, has been examining the chemical composition of the comet’s atmosphere, or coma, at far-ultraviolet wavelengths.
At these wavelengths, Alice allows scientists to detect some of the most abundant elements in the Universe such as hydrogen, oxygen, carbon and nitrogen.  The spectrograph splits the comet’s light into its various colours – its spectrum – from which scientists can identify the chemical composition of the coma gases.
In a paper accepted for publication in the journal Astronomy and Astrophysics, scientists report the detections made by Alice from Rosetta’s first four months at the comet, when the spacecraft was between 10 km and 80 km from the centre of the comet nucleus.
For this study, the team focused on the nature of ‘plumes’ of water and carbon dioxide gas erupting from the comet’s surface, triggered by the warmth of the Sun. To do so, they looked at the emission from hydrogen and oxygen atoms resulting from broken water molecules, and similarly carbon atoms from carbon dioxide molecules, close to the comet nucleus.
They discovered that the molecules seem to be broken up in a two-step process.
First, an ultraviolet photon from the Sun hits a water molecule in the comet’s coma and ionises it, knocking out an energetic electron. This electron then hits another water molecule in the coma, breaking it apart into two hydrogen atoms and one oxygen, and energising them in the process. These atoms then emit ultraviolet light that is detected at characteristic wavelengths by Alice.
Similarly, it is the impact of an electron with a carbon dioxide molecule that results in its break-up into atoms and the observed carbon emissions.
“Analysis of the relative intensities of observed atomic emissions allows us to determine that we are directly observing the ‘parent’ molecules that are being broken up by electrons in the immediate vicinity, about 1 km, of the comet’s nucleus where they are being produced,” says Paul Feldman, professor of physics and astronomy at the Johns Hopkins University in Baltimore, and lead author of the paper discussing the results.
By comparison, from Earth or from Earth-orbiting space observatories such as the Hubble Space Telescope, the atomic constituents of comets can only be seen after their parent molecules, such as water and carbon dioxide, have been broken up by sunlight, hundreds to thousands of kilometres away from the nucleus of the comet.
Quelle: ESA
Update: 5.06.2015
This impressive view of Comet 67P/Churyumov-Gerasimenko was captured on 21 May from a distance of 156.8 km from the comet centre. It is a single frame image with a resolution of 13.4 m/pixel, and measures 13.7 km across. The intensities and contrast have been adjusted to emphasise the activity of the comet.
Processed image of Comet 67P/C-G taken by Rosetta's NAVCAM on 21 May 2015. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
Activity is seen all around the nucleus, but in this view is most notable around the head, with many distinct, bright jets streaming from the surface. Intricate patterns of activity are also cast around the neck and against the shadow of the small lobe.
The rather flat face on the comet’s large lobe, comprising parts of Aker and Khepry, dominates the view of the nucleus. The elongate Aten region lies adjacent, with diffuse wisps of activity hanging in front of this shadowed depression.
A fainter cloud of activity is also visible below the shadowed underside of the comet’s large lobe.
Today’s image also makes for a nice comparison with the 26 April entry, which shows the comet in a similar orientation.
The original 1024 x 1024 pixel image is provided below:
Quelle: ESA
Update: 7.06.2015
Today's CometWatch entry was taken on 23 May, when Rosetta was 138.1 km from the centre of Comet 67P/Churyumov-Gerasimenko. The single frame NAVCAM image has resolution of 11.8 m/pixel and measures 12.1 km across.
Cropped and processed single frame NAVCAM image of Comet 67P/C-G taken on 23 May 2015 from a distance of 138.1 km to the comet centre. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
The image was processed in LightRoom to convey the ever increasing activity of the comet, with swirling outflows of material emanating from various parts of the nucleus.
In this orientation, with the large comet lobe up and the small one down, the neck region remains hidden in shadows. The small lobe is dominated by the rough Anuket region and the sharp edge that separates it from Serqet, which lies mostly out of view to the bottom.
A diffuse glow appears to emanate from a portion of the small lobe that is hidden from sight in this image, suggestive of the activity seen close to Hatmehit, the circular depression on the small lobe, in CometWatch 20 May.
On the large lobe, we see parts of the complex terrain in and surrounding the Atum region. Some of its features are casting shadows on the smoother Anubis region towards the centre of this view..
As shown in previously published images of this portion of 67P/C-G, a curious set of aligned linear features can be seen. Revisit the CometWatch entries taken on 21 March 2015 (and close-up from 24 October 2014) as well as on 16 January 2015, 20 November and 19 September 2014, to view this landmark and its surroundings in more detail and from different orientations.
The original 1024 x 1024 image is provided below:
Quelle: ESA
Update: 9.06.2015
Today’s CometWatch entry was taken on 1 June 2015, from a distance of 209 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image scale is 17.8 m/pixel and the image measures 18.2 km across.
Comet 67P/C-G on 1 June. The image has been processed to highlight the comet's activity. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
The image has been processed to bring out the details of the comet’s activity, which can be seen all around the sunlit side of the comet.
In this orientation the comet’s small lobe is to the left and the large lobe to the right, with much of the southern hemisphere facing towards the spacecraft.
The outline of the rim of the large depression Hatmehit can be seen at the very far left, while at the far right a hint of Imhotep can just be made out. The flat surface at the top of the large lobe in this orientation is in the Aker/Khepry region.
The rugged terrain that faces us has only become visible in more recent months, having previously been cast in shadow. But even at a distance of over 200 km it is clear that this is a complex region with a variety of surface textures.
The original 1024 x 1024 pixel image is provided below:
Quelle: ESA
Activity on Comet 67P/Churyumov-Gerasimenko continues to rise, with new images from OSIRIS showing that some regions remain active even after nightfall. This report is provided by the OSIRIS team at the Max Planck Institute for Solar System Research (MPS) in Germany.
Rosetta’s scientific camera OSIRIS captured the sunset jets in the Ma’at region of the comet’s small lobe in late April. Images were taken approximately half an hour after the Sun had set over the region and show clearly defined jets of dust escaping into space.
Comet 67P/C-G on 25 April 2015, from a distance of approximately 93 kilometres, seen through the narrow-angle OSIRIS camera. The image shows jets emanating from the comet’s small lobe after nightfall. The  exposure time was 0.096s. The image is presented to show the details of the jets, rather than the nucleus. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
“Only recently have we begun to observe dust jets persisting even after sunset,” says OSIRIS Principal Investigator Holger Sierks from the Max Planck Institute for Solar System Research (MPS) in Germany.
Until recently, the comet’s activity originated from illuminated areas on the day side. As soon as the Sun set, these jets subsided and did not re-awaken until after sunrise the following day. One recent exception was the event captured on 12 March, which caught the onset of a dust jet at the brink of dawn, in the Imhotep region on the comet’s large lobe.
Close-up of the dust jets seen on 25 April 2015 on the comet’s small lobe. Credits: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
According to the OSIRIS scientists, the sunset jets are another sign of the comet’s increasing activity.
“Currently, 67P is rapidly approaching perihelion in mid-August,” says Sierks. “The solar irradiation is getting more and more intense, the illuminated surface warmer and warmer.”
At the time the image was taken, the comet was 270 million kilometres from the Sun. By the time the comet reaches perihelion on 13 August, the separation will be just 186 million kilometres.
The OSIRIS team think that the comet can store the incoming heat for some time beneath its surface, resulting in sustained activity from these regions even after nightfall.
“While the dust covering the comet’s surface cools rapidly after sunset, deeper layers remain warm for a longer period of time,” says OSIRIS scientist Xian Shi from the MPS, who is studying the sunset jets.
The scientists suspect that the comet’s supply of frozen gases that fuel the comet’s activity exists in these deeper layers.
Previous comet missions, such as Stardust’s flyby of Comet 81P/Wild 2 and Deep Impact’s mission to Comet 9P/Tempel 1, also found evidence of jets sustained on the night side.
“But only the high-resolution images of OSIRIS now allow us to study this phenomenon in detail,” adds Sierks.
The scientific imaging system OSIRIS was built by a consortium led by the Max Planck Institute for Solar System Research (Germany) in collaboration with CISAS, University of Padova (Italy), the Laboratoire d'Astrophysique de Marseille (France), the Instituto de Astrofísica de Andalucia, CSIC (Spain), the Scientific Support Office of the European Space Agency (The Netherlands), the Instituto Nacional de Técnica Aeroespacial (Spain), the Universidad Politéchnica de Madrid (Spain), the Department of Physics and Astronomy of Uppsala University (Sweden), and the Institute of Computer and Network Engineering of the TU Braunschweig (Germany). OSIRIS was financially supported by the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), and Sweden (SNSB) and the ESA Technical Directorate.
Quelle: ESA

Update: 10.06.2015
Rosetta deckt Prozesse im Kometenkoma, der Atmosphäre eines Kometen, auf.
Die ESA-Raumsonde Rosetta hat während ihrer andauernden Untersuchungen des Kometen 67P/ Tschurjumow-Gerassimenko eine unerwartete Entdeckung gemacht: Sie hat den Prozess offengelegt, der den rapiden Zerfall von Wasser- und Kohlendioxidmolekülen auslöst, die von der Kometenoberfläche freigegeben werden.
Die Rosetta-Mission der ESA hat den Kometen im August 2014 erreicht. Seitdem umkreist die Raumsonde den Kometen oder fliegt an ihm vorbei – in Entfernungen von acht bis hin zu einigen Hundert Kilometern. Während dieser Flüge sammelt Rosetta, ausgestattet mit elf wissenschaftlichen Instrumenten, Daten zu allen Aspekten der Kometenumwelt.
Eines dieser Geräte, der von der NASA gelieferte Alice-Spektograf, untersucht die chemische Zusammensetzung der Kometenatmosphäre, auch Kometenkoma genannt, in langen Ultraviolett-Wellenlängenbereichen.
In diesen Wellenlängenbereichen ermöglicht es Alice den Wissenschaftlern, einige der am häufigsten vorkommenden Elemente im Universum aufzuspüren. Dazu gehören Wasserstoff, Sauerstoff, Kohlenstoff und Stickstoff. Der Spektograph spaltet das Licht des Kometen in seine verschiedenen Farben, sein Spektrum. So können die Wissenschaftler die chemische Zusammensetzung der Komagase bestimmen.
In einem Paper, das von der Fachzeitschrift Astronomy and Astrophysics zur Publikation angenommen wurde, beschreiben Wissenschaftler die Entdeckungen des Alice-Spektographen, die während Rosettas erster vier Monate am Kometen gemacht wurden. In dieser Zeit war die Raumsonde zwischen zehn und 80 Kilometer vom Mittelpunkt des Kometenkerns entfernt.
Für diese Studie konzentrierte sich das Team auf die Beschaffenheit der Wasser- und Kohlendioxidschwaden, die der Komet an seiner Oberfläche ausspeit. Dieses Hervorbrechen wird von der Wärme der Sonne ausgelöst. Dafür analysierten die Wissenschaftler nahe am Kometenkern die Emissionen von Wasserstoff- und Sauerstoffatomen, die ein Ergebnis aufgebrochener Wassermoleküle sind. Ebenso studierten sie Kohlenstoffatome von Kohlendioxidmolekülen.
Die Wissenschaftler entdeckten, dass die Moleküle wahrscheinlich in einem zweistufigen Prozess aufgebrochen werden.
Zunächst trifft ein ultraviolettes Photon der Sonne ein Wassermolekül im Kometenkoma und ionisiert es. Dabei löst das Photon ein energetisches Elektron aus dem Molekül heraus. Dieses Elektron trifft dann auf ein anderes Wassermolekül im Koma und spaltet es in zwei Wasserstoff- sowie ein Sauerstoffatom auf. Während dieses Prozesses energetisiert das Elektron die Atome. Diese Atome geben dann ultraviolettes Licht ab, dessen charakteristische Wellenlängen vom Alice-Spektographen entdeckt wurden.
Gleichermaßen führt der Aufprall eines Elektrons auf ein Kohlendioxidmolekül zu einem Aufspalten in Atome und die beobachteten Kohlenstoffemissionen.
„Durch die Analyse der relativen Intensitäten der beobachteten atomaren Emissionen konnten wir feststellen, dass wir tatsächlich die ‚Eltern’-Moleküle beobachten, die von Elektronen in unmittelbarer Nähe des Kometenkerns, etwa einen Kilometer von ihm entfernt, aufgebrochen werden, und zwar an dem Ort, an dem sie entstehen“, sagt Paul Feldman, Professor für Physik und Astronomie an der Johns Hopkins University in Baltimore. Feldman ist der Erstautor des Papers, in dem die Ergebnisse diskutiert werden.
Von der Erde oder von erdumkreisenden Observatorien wie dem Hubble-Weltraumteleskop aus können die atomaren Bestandteile von Kometen dagegen nur beobachtet werden, nachdem die Elternmoleküle (zum Beispiel Wasser oder Kohlendioxid) vom Sonnenlicht aufgebrochen worden sind – Hunderte bis Tausende Kilometer vom Kometenkern entfernt.
„Diese Entdeckung, über die wir jetzt berichten, kam ziemlich unerwartet“, sagt Alice-Projektleiter Alan Stern, Associate Vice President der Abteilung Weltraumwissenschaften und -technik am Southwest Research Institute (SwRI).
„Es zeigt uns auf, wie wichtig es ist, zu Kometen zu fliegen, um sie aus der Nähe analysieren zu können. Denn diese Entdeckung wäre niemals von einem Observatorium auf der Erde oder in einem Erdorbit gemacht worden, weder von einem existierenden noch von einem geplanten. Und diese Entdeckung verändert unser Wissen über Kometen fundamental.“
„Durch die Analyse der Emissionen von Wasserstoff- und Sauerstoffatomen, die von den Wassermolekülen abgespalten werden, können wir außerdem die Lage sowie die Struktur der Wasserschwaden, die aus der Kometenoberfläche herausbrechen, bestimmen“, sagt Mitautor Joel Parker, stellvertretender Direktor der Abteilung Weltraumwissenschaften und -technik am SwRI in Boulder, Colorado.
Das Wissenschaftler-Team vergleicht diese Aufspaltung der Moleküle mit dem Prozess, der für die Schwaden auf Jupiters vereistem Mond Europa vorgeschlagen wurde – mit dem Unterschied, dass die Elektronen am Kometen von Solarphotonen produziert werden. Die Elektronen auf Europa kommen aus Jupiters Magnetosphäre.
Die Ergebnisse des Alice-Spektographen werden von Daten, die andere Rosetta-Geräte gesammelt haben, bekräftigt. Zu nennen sind hier MIRO, ROSINA und VIRTIS, die in der Lage sind, die vielen verschiedenen Komabestandteile sowie deren Variationen im Zeitverlauf zu analysieren, sowie Geräte zur Partikelerkennung wie RPC-IES.
„Diese frühen Ergebnisse des Alice-Spektografen zeigen, wie wichtig es ist, einen Kometen in unterschiedlichen Wellenlängenbereichen und mit unterschiedlichen Technologien zu untersuchen, um so verschiedene Aspekte der Kometenumwelt zu erforschen“, sagt Matt Taylor, Rosetta-Projektwissenschaftler der ESA.
„Wir verfolgen derzeit aktiv, wie sich der Komet entwickelt, während er auf seinem Orbit der Sonne immer näher kommt, bis er im August das Perihel erreicht. Wir sehen, wie die Schwaden wegen der zunehmenden Sonnenwärme immer aktiver werden und untersuchen die Auswirkungen der Kometeninteraktion mit dem Sonnenwind.“
Quelle: ESA
Update: 12.06.2015

Best candidates' for lost Philae comet lander

The European Space Agency (Esa) has released some pictures that may include its lost comet lander, Philae.
Whether that really is the case is far from certain, however.
The features of interest in the images are on the scale of a few bright pixels and could very easily just be a trick of the light.
Philae was dropped on to the surface of Comet 67P by its mothership Rosetta in November last year, and has not been heard from since its battery ran flat.
The washing-machine-sized robot bounced a good kilometre from its intended touchdown point, hence the doubts about its current precise whereabouts on the 4km-wide icy dirt-ball.
Mission teams have a very good idea of where Philae ought to be - inside a patch of terrain measuring perhaps a few tens of metres across. But getting the photographic evidence to prove it is there has been very challenging.
Rosetta acquired a series of pictures of the suspected resting region back in December, and scientists have been poring over the data ever since.
They have been looking for differences in this image-set compared with pictures taken before the landing, and Thursday's release from Esa represents what can only be described as "the best candidates" for Philae. One is rated higher than the others, but even this cannot be promoted with particularly high confidence, agency officials have told the BBC.
Even after some smart processing techniques were applied, it is still just a bright splodge. Esa has rendered a movie that zooms in on this top candidate (MOV) to make it easier for people to discern the feature being discussed.
Stephan Ulamec, the lander manager with the German space agency, said recently: "In the best images we have after the landing, with the correct illumination and taken from an altitude of 20km - the lander would be in the range of two-times-three or three-times-three pixels. And this is exactly the problem: it's not very distinct. We have to assume there is some shadowing effect on the lander that will camouflage it.
"And, yes, the later in the evening and the more wine you drink - the more landers you're able to identify in this terrain," he memorably joked at this year's European Geosciences Union General Assembly in Vienna in April.
Philae bounced more than 1,200m across the surface before stopping in a ditch
Before it lost power, Philae itself returned images of its surroundings, which showed it was in some kind of ditch. The location, dubbed Abydos, is on the "head" of the duck-shaped comet.
High walls were blocking sunlight from reaching Philae's solar panels, denying the robot the ability to charge its battery.
The mission teams must now hope that those illuminations conditions will improve as Comet 67P moves closer to the Sun in the course of the next few weeks. They should. And if Philae can muster enough charge to boot up, the orbiting Rosetta will be listening for even the briefest of radio communications.
The first contacts - if they come - will be short because the battery will almost immediately die again as the transmitter equipment is fired up. But in time - perhaps by July - Philae could be getting enough intense sunlight to generate a useful amount of electricity.
The big concern, however, is the cold. For many of the lander's components this is not a problem, but there will be electronics that have experienced temperatures in the past few months that are below their "qualified" limits. This will include the onboard computer and the communications unit, both of which sit inside a so-called "warm compartment".
"A problem one may face with these low temperatures is some thermal stresses on the electronics boards, and they may damage soldering points," Dr Ulamec explained.
"All the instruments and mechanisms that are outside the warm compartment - they are qualified for very low temperatures because we were expecting those even if we had landed in the planned landing location."
Mission teams had the idea to send Rosetta on a quick, close flyby of the suspected resting place this month, to acquire new images with a higher resolution than those featured on this page. But this possibility has long since been abandoned. So much dust is coming off the active comet that Rosetta's navigation systems get confused if the probe ventures too close.
Rosetta has been pulled back from 67P and currently keeps a watching brief from a distance of about 100km.
The probe's distance from Earth is about 309 million km, and about 218 million km from the Sun.
Quelle: BBC
Update: 14.06.2015
Rosetta-Komet: Staubfontänen in der Nacht
Auch nach Einbruch der Dunkelheit bleibt der  Komet 67P/Churyumov-Gerasimenko aktiv und spuckt Staubfontänen ins All. 
Wenn die Nacht anbricht auf dem Rosetta-Kometen 67P/Churyumov-Gerasimenko, bleibt der bizarr geformte Körper weiterhin aktiv. Das belegen neue Aufnahmen der Ma’at Region auf dem „Kopf“ des Kometen, die OSIRIS, das wissenschaftliche Kamerasystem an Bord der Raumsonde Rosetta, am 25. April dieses Jahres eingefangen hat. Sie entstanden etwa eine halbe Stunde, nachdem die Sonne über dieser Region untergegangen war, und zeigen mehrere klar unterscheidbare Staubfontänen, die ins All entweichen. Forscher des OSIRIS-Teams glauben, dass die zunehmende Erwärmung des Kometen für das neu beobachtete Phänomen verantwortlich ist.
„Staubfontänen, die auch nach Sonnenuntergang weiter bestehen, beobachten wir erst seit Kurzem“, sagt OSIRIS-Teamleiter Holger Sierks vom Max-Planck-Institut für Sonnensystemforschung (MPS) in Göttingen. In den vergangenen Monaten ging die Aktivität des Kometen von beleuchteten Flächen auf der Tagseite aus. Sobald es dunkelte, kamen die Fontänen zum Erliegen und erwachten erst nach Sonnenaufgang wieder zu neuem Leben. Eine Ausnahme bildet eine Aufnahme vom 12. März 2015, die das Einsetzen einer Staubfontäne während des Morgengrauens zeigt.
Die Fontänen, die nun auch nach Sonnenuntergang auftreten, sind nach Ansicht der OSIRIS-Wissenschaftler ein weiteres Zeichen für die zunehmende Aktivität des Kometen. „Derzeit nähert sich 67P rasch seinem sonnennächsten Punkt, den er bereits Mitte August erreicht“, so Sierks. Zum Zeitpunkt der Aufnahme trennten nur noch etwa 270 Millionen Kilometer Sonne und Komet. „Die Sonneneinstrahlung wird immer intensiver, die beleuchtete Oberfläche immer wärmer“, fügt Sierks hinzu.
Detailaufnahme der Staubfontänen.
Erste Modellrechnungen deuten darauf hin, dass der Komet unter seiner Oberfläche diese Wärme für einige Zeit speichern kann. „Während der oberflächliche Staub nach Sonnenuntergang rasch abkühlt, bleiben tiefer liegende Schichten länger warm“, erklärt OSIRIS-Wissenschaftlerin Xian Shi vom MPS, die die nächtlichen Fontänen untersucht. Dort vermuten Rosetta-Wissenschaftler den Vorrat an gefrorenen Gasen, der die Aktivität des Kometen speist.
Bereits ältere Kometenmissionen wie Stardust zum Kometen 81P/Wild 2 und Deep Impact zum Kometen 9P/Tempel 1 hatten Hinweise auf Fontänen geliefert, die auf der Nachtseite entstehen. „Doch erst die hochaufgelösten Bilder von OSIRIS erlauben es uns nun, dieses Phänomen detailliert zu studieren“, so Sierks.
Rosetta ist eine Mission der Europäischen Weltraumagentur ESA mit Beiträgen der Mitgliedsstaaten und der amerikanischen Weltraumagentur NASA. Rosettas Landeeinheit Philae wurde von einem Konsortium unter Leitung des Deutschen Zentrums für Luft- und Raumfahrt (DLR), des Max-Planck-Instituts für Sonnensystemforschung (MPS) und der französischen und italienischen Weltraumagentur (CNES und ASI) zur Verfügung gestellt. Rosetta ist die erste Mission in der Geschichte, die einen Kometen anfliegt, ihn auf seinem Weg um die Sonne begleitet und eine Landeeinheit auf seiner Oberfläche absetzt.
Das wissenschaftliche Kamerasystem OSIRIS wurde von einem Konsortium unter Leitung des Max-Planck-Instituts für Sonnensystemforschung in Zusammenarbeit mit CISAS, Universität Padova (Italien), Laboratoire d'Astrophysique de Marseille (Frankreich), Instituto de Astrofísica de Andalucia, CSIC (Spanien), Scientific Support Office der ESA (Niederlande), Instituto Nacional de Técnica Aeroespacial (Spanien), Universidad Politéchnica de Madrid (Spanien), Department of Physics and Astronomy of Uppsala University (Schweden) und dem Institut für Datentechnik und Kommunikationsnetze der TU Braunschweig gebaut. OSIRIS wurde finanziell unterstützt von den Weltraumagenturen Deutschlands (DLR), Frankreichs (CNES), Italiens (ASI), Spaniens (MEC) und Schwedens (SNSB).

Tags: Raumfahrt 


Sonntag, 14. Juni 2015 - 10:24 Uhr

Astronomie - In Helium gehüllte Planeten können häufig in unserer Galaxie anzutreffen sein


They wouldn't float like balloons or give you the chance to talk in high, squeaky voices, but planets with helium skies may constitute an exotic planetary class in our Milky Way galaxy. Researchers using data from NASA's Spitzer Space Telescope propose that warm Neptune-size planets with clouds of helium may be strewn about the galaxy by the thousands.
"We don't have any planets like this in our own solar system," said Renyu Hu, NASA Hubble Fellow at the agency's Jet Propulsion Laboratory in Pasadena, California, and lead author of a new study on the findings accepted for publication in the Astrophysical Journal. "But we think planets with helium atmospheres could be common around other stars."
Prior to the study, astronomers had been investigating a surprising number of so-called warm Neptunes in our galaxy. NASA's Kepler space telescope has found hundreds of candidate planets that fall into this category. They are the size of Neptune or smaller, with tight orbits that are closer to their stars than our own sizzling Mercury is to our sun. These planets reach temperatures of more than 1,340 degrees Fahrenheit (1,000 Kelvin), and orbit their stars in as little as one or two days.
In the new study, Hu and his team make the case that some warm Neptunes -- and warm sub-Neptunes, which are smaller than Neptune -- could have atmospheres enriched with helium. They say that the close proximity of these planets to their searing stars would cause the hydrogen in their atmospheres to boil off.
"Hydrogen is four times lighter than helium, so it would slowly disappear from the planets' atmospheres, causing them to become more concentrated with helium over time," said Hu. "The process would be gradual, taking up to 10 billion years to complete." For reference, our planet Earth is about 4.5 billion years old.
Warm Neptunes are thought to have either rocky or liquid cores, surrounded by gas. If helium is indeed the dominant component in their atmospheres, the planets would appear white or gray. By contrast, the Neptune of our own solar system is a brilliant azure blue. The methane in its atmosphere absorbs the color red, giving Neptune its blue hue.
A lack of methane in one particular warm Neptune, called GJ 436b, is in fact what led Hu and his team to develop their helium planet theory. Spitzer had previously observed GJ 436b, located 33 light-years away, and found evidence for carbon but not methane. This was puzzling to scientists, because methane molecules are made of one carbon and four hydrogen atoms, and planets like this are expected to have a lot of hydrogen. Why wasn't the hydrogen linking up with carbon to produce methane?
According to the new study, the hydrogen might have been slow-cooked off the planet by radiation from the host stars. With less hydrogen around, the carbon would pair up with oxygen to make carbon monoxide. In fact, Spitzer found evidence for a predominance of carbon monoxide in the atmosphere of GJ 436b.
The next step to test this theory is to look at other warm Neptunes for signs of carbon monoxide and carbon dioxide, which are indicators of helium atmospheres. The team says this might be possible with the help of NASA's Hubble Space Telescope, and NASA's upcoming James Webb Space Telescope may one day directly detect that helium.
Meanwhile, the wacky world of exoplanets continues to surprise astronomers.
"Any planet one can imagine probably exists, out there, somewhere, as long as it fits within the laws of physics and chemistry," said co-author Sara Seager of the Massachusetts Institute of Technology in Cambridge and JPL. "Planets are so incredibly diverse in their masses, sizes and orbits that we expect this to extend to exoplanet atmospheres."
A third author of the paper is Yuk Yung of the California Institute of Technology in Pasadena and JPL.
JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.
Quelle: NASA

Tags: Astronomie 


Samstag, 13. Juni 2015 - 22:00 Uhr

Astronomie - Einsame Galaxy 'Lost in Space'


JUNE 10, 2015: This magnificent spiral galaxy is at the edge of what astronomers call the Local Void. The Local Void is a huge volume of space that is at least 150 million light-years across that doesn't seen to contain anything much. There are no obvious galaxies. This void is simply part of the structure of the universe where matter grows clumpy over time so that galaxies form clusters and chains, which are separated by regions mostly devoid of galaxies. This results in sort of a "soap bubble" structure on large scales. The galaxy, as photographed by NASA's Hubble Space Telescope, is especially colorful where bright red patches of gas can be seen scattered through its spiral arms. Bright blue regions contain newly forming stars. Dark brown dust lanes snake across the galaxy's bright arms and center, giving it a mottled appearance.


Most galaxies are clumped together in groups or clusters. A neighboring galaxy is never far away. But this galaxy, known as NGC 6503, has found itself in a lonely position, at the edge of a strangely empty patch of space called the Local Void.
The Local Void is a huge stretch of space that is at least 150 million light-years across. It seems completely empty of stars or galaxies. The galaxy's odd location on the edge of this never-land led stargazer Stephen James O'Meara to dub it the "Lost-In-Space galaxy" in his 2007 book, Hidden Treasures.
NGC 6503 is 18 million light-years away from us in the northern circumpolar constellation of Draco. NGC 6503 spans some 30,000 light-years, about a third of the size of the Milky Way.
This Hubble Space Telescope image shows NGC 6503 in striking detail and with a rich set of colors. Bright red patches of gas can be seen scattered through its swirling spiral arms, mixed with bright blue regions that contain newly forming stars. Dark brown dust lanes snake across the galaxy's bright arms and center, giving it a mottled appearance.
The Hubble Advanced Camera for Surveys data for NGC 6503 were taken in April 2003, and the Wide Field Camera 3 data were taken in August 2013.
Object Name: NGC 6503

Quelle: NASA

Tags: Astronomie 


Samstag, 13. Juni 2015 - 17:50 Uhr

Luftfahrt-History - 1931: Berlin-New-York in einer Stunde


Aus dem CENAP-Archiv:


Quelle: Science and Mechanics, CENAP-Archiv

Tags: Luftfahrt 


Samstag, 13. Juni 2015 - 10:45 Uhr

Raumfahrt - Letzte Blicke auf die Erde vor der Rückkehr von Astronaut Terry Virts (ISS-Crew-42/43)


American astronaut Terry Virts of NASA took this photo of the Great Pyramids of Egypt on June 10, his last full day in space, and posted it on Twitter before returning to Earth on a Soyuz spacecraft on June 11, 2015. He had spent 200 days living on the International Space Station. 
Credit: NASA via Terry Virts
Astronaut Terry Virts knows how to spend his last day in space: gazing at planet Earth from afar and posting photos of that jaw-dropping view online for all to see.
Before a Soyuz space capsule returned Virts to Earth Thursday (June 11), the NASA astronaut took time out in space to photograph the Earth below, capturing spectacular vistas of the Great Pyramids of Giza in Egypt, our home planet at night and what looked to be a stunning sunrise.
Virts seemed especially proud of his photo of the pyramids, which shows the massive structures with amazing clarity, apparently because he had been trying to capture the view for the past six months."It took me to until my last day in space to get a good picture of these," Virts wrote on Twitter, where he posted photos, Vine videos and mission updates as @AstroTerry. Virts and two crewmates spent nearly 200 days living and working on the International Space Station.
Green auroras dance over Earth in this photo by NASA astronaut Terry Virts captured on June 10, his last full day in space before landing on a Soyuz spacecraft on June 11, 2015.
In another shot, the space station soars over Earth at night, with a green ribbon of aurora dancing over the planet.
"I will miss this view!" Virts wrote, and then posted four more amazing views from the station's Cupola — a seven-windowed observation deck — in a separate post.
Virts also posted a photo of the Soyuz TMA-15M spacecraft that ferried him back to Earth alongside crewmates Anton Shkaplerov of Russia and astronaut Samantha Cristoforetti of Italy. "My ride back to Earth today," he wrote.
And after uploading a Vine video of the South China Sea at night, Virts cast his camera eye at the day-lit Earth. One photo, simply captioned "Home," shows the curve of the Earth as a new day begins on the planet.
Virts' final shot was perhaps his most poignant: a view of the partially lit Earth, with the bright sun shining overhead and parts of the space station's solar arrays and robotic arm visible around the sides. The image is reminiscent of a sciencefiction film, but comes straight from Virts' camera.
"The last picture I took this mission," Virts wrote of the view.
Sun Over Earth by Virts 
Pin It NASA astronaut Terry Virts captured this view of the sun over Earth on his last day in space as he prepared to leave the International Space Station on June 11, 2015. It is the last photo he took before returning to Earth that day.
Credit: NASAView full size image
Astronauts have routinely shared photos and videos of their lives in space using Twitter, Instagram, YouTube and other social media since 
NASA astronaut Terry Virts captured this view of the sun over Earth on his last day in space as he prepared to leave the International Space Station on June 11, 2015. It is the last photo he took before returning to Earth that day.
2009, when astronaut Mike Massimino became the first space traveler to join that digital final frontier. Cristoforetti's amazing space photos and videos also have provided an eye-opening glimpse of life in space over the past six months.
Virts, Shkaplerov and Cristoforetti launched to the space station in late November 2014 and served first with the station's Expedition 42 crew and then stayed aboard to form the core of the Expedition 43 crew, which Virts commanded. NASA astronaut Scott Kelly and cosmonauts Mikhail Kornienko and Gennady Padalka remained on the space station, with Kelly and Kornienko in the midst of a yearlong mission in orbit.
Quelle: SC

Tags: Raumfahrt 


Samstag, 13. Juni 2015 - 08:00 Uhr

Raumfahrt - NASA bereitet sich vor auf erste interplanetare CubeSats Next Mission 2016 zum Mars


NASA's two small MarCO CubeSats will be flying past Mars in 2016 just as NASA's next Mars lander, InSight, is descending through the Martian atmosphere and landing on the surface. MarCO, for Mars Cube One, will provide an experimental communications relay to inform Earth quickly about the landing.
Credits: NASA/JPL-Caltech
When NASA launches its next mission on the journey to Mars – a stationary lander in 2016 – the flight will include two CubeSats. This will be the first time CubeSats have flown in deep space.  If this flyby demonstration is successful, the technology will provide NASA the ability to quickly transmit status information about the main spacecraft after it lands on Mars.
The twin communications-relay CubeSats, being built by NASA's Jet Propulsion Laboratory (JPL), Pasadena, California, constitute a technology demonstration called Mars Cube One (MarCO).  CubeSats are a class of spacecraft based on a standardized small size and modular use of off-the-shelf technologies. Many have been made by university students, and dozens have been launched into Earth orbit using extra payload mass available on launches of larger spacecraft.
The full-scale mock-up of NASA's MarCO CubeSat held by Farah Alibay, a systems engineer for the technology demonstration, is dwarfed by the one-half-scale model of NASA's Mars Reconnaissance Orbiter behind her.
Credits: NASA/JPL-Caltech
The basic CubeSat unit is a box roughly 4 inches (10 centimeters) square. Larger CubeSats are multiples of that unit. MarCO's design is a six-unit CubeSat – about the size of a briefcase -- with a stowed size of about 14.4 inches (36.6 centimeters) by 9.5 inches (24.3 centimeters) by 4.6 inches (11.8 centimeters).
MarCO will launch in March 2016 from Vandenberg Air Force Base, California on the same United Launch Alliance Atlas V rocket as NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) lander. Insight is NASA’s first mission to understand the interior structure of the Red Planet. MarCO will fly by Mars while InSight is landing, in September 2016.
“MarCO is an experimental capability that has been added to the InSight mission, but is not needed for mission success,” said Jim Green, director of NASA’s planetary science division at the agency’s headquarters in Washington. “MarCO will fly independently to Mars."
During InSight’s entry, descent and landing (EDL) operations on Sept. 28, 2016, the lander will transmit information in the UHF radio band to NASA's Mars Reconnaissance Orbiter (MRO) flying overhead. MRO will forward EDL information to Earth using a radio frequency in the X band, but cannot simultaneously receive information over one band while transmitting on another. Confirmation of a successful landing could be received by the orbiter more than an hour before it’s relayed to Earth.
MarCO’s radio is about softball-size and provides both UHF (receive only) and X-band (receive and transmit) functions capable of immediately relaying information received over UHF.
The two CubeSats will separate from the Atlas V booster after launch and travel along their own trajectories to the Red Planet. After release from the launch vehicle, MarCO's first challenges are to deploy two radio antennas and two solar panels. The high-gain, X-band antenna is a flat panel engineered to direct radio waves the way a parabolic dish antenna does. MarCO will be navigated to Mars independently of the InSight spacecraft, with its own course adjustments on the way.
Ultimately, if the MarCO demonstration mission succeeds, it could allow for a “bring-your-own” communications relay option for use by future Mars missions in the critical few minutes between Martian atmospheric entry and touchdown.
By verifying CubeSats are a viable technology for interplanetary missions, and feasible on a short development timeline, this technology demonstration could lead to many other applications to explore and study our solar system.
JPL manages MarCO, InSight and MRO for NASA's Science Mission Directorate in Washington. Technology suppliers for MarCO include: Blue Canyon Technologies of Boulder, Colorado, for the attitude-control system; VACCO Industries of South El Monte, California, for the propulsion system; AstroDev of Ann Arbor, Michigan, for electronics; MMA Design LLC, also of Boulder, for solar arrays; and Tyvak Nano-Satellite Systems Inc., a Terran Orbital Company in San Luis Obispo, California, for the CubeSat dispenser system. 
Quelle: NASA

Tags: Raumfahrt 


Freitag, 12. Juni 2015 - 22:15 Uhr

Astronomie - NASA, Universität Forscher diskutieren Suche nach Leben im Sonnensystem, und darüber hinaus .


NASA and university scientists will discuss at 2 p.m. EDT, Tuesday June 16, astrobiology research activities and technology that are advancing the search for evidence of habitability in our solar system and beyond. The briefing will air live on NASA Television and the agency’s website.
Briefing topics will include the quest for evidence of habitability and life on Mars, plans for exploring the habitability of Europa and Enceladus, and progress in identifying signs of habitability on exoplanets.
The briefing will be held during the 2015 Astrobiology Science Conference in Chicago June 15-19 in Salon A5 of the Hilton Downtown Chicago, located at 720 South Michigan Avenue.
Briefing participants are:
John Grunsfeld, associate administrator for Science at NASA Headquarters in Washington
Vikki Meadows, professor of astronomy and principal investigator at the University of Washington’s Virtual Planetary Laboratory in Seattle
Britney Schmidt, assistant professor in the Department of Earth and Atmospheric Sciences at the Georgia Institute of Technology, and principal investigator for the NASA-funded project Sub-Ice Marine and Planetary Analog Ecosystems
Alexis Templeton, associate professor in the Department of Geological Sciences at the University of Colorado-Boulder, and principal investigator for the NASA Astrobiology Institute Rock-Powered Life team
Quelle: NASA

Tags: Astronomie und darüber hinaus . 


Freitag, 12. Juni 2015 - 18:45 Uhr

Raumfahrt - ESA-ISS-Futura-Mission:ESA-Astronaut Samantha Cristoforetti - Expedition 42/43



Quelle: ESA


Update: 13.12.2014

Quelle: ESA


Update: 1.01.2014



View of the Alps From Space


Expedition 42 Flight Engineer Samantha Cristoforetti of the European Space Agency (ESA) took this photograph of the Alps from the International Space Station, and posted it to social media on Tuesday, Dec. 23, 2014. She wrote, "I'm biased, but aren't the Alps from space spectacular? What a foggy day on the Po plane, though! #Italy"
Quelle: ESA



Update: 12.06.2015 

Samantha Cristoforetti back on Earth


ESA astronaut Samantha Cristoforetti, NASA astronaut Terry Virts and Russian commander Anton Shkaplerov landed safely today in the Kazakh steppe after a three-hour ride in their Soyuz spacecraft. They left the International Space Station at 10:20 GMT at the end of their six-month stay on the research complex.

Soyuz TMA-15M braked from the Station’s cruising speed of almost 28 800 km/h and entered the atmosphere shortly afterwards. The small descent module separated as planned and parachutes deployed to slow the vehicle down even more.
The module fired retrorockets moments before landing and springs in the moulded seats reduced the impact of hitting the steppe at 13:44 GMT. Teams were on hand within minutes to help them out.
They leave behind NASA astronaut Scott Kelly and cosmonauts Mikhail Kornienko and Gennady Padalka to look after the Station and run experiments. Scott and Mikhail are almost a third of the way through their almost a  year stay in space.

Landing of the Soyuz TMA-15M spacecraft


Samantha is the seventh ESA astronaut and the first female ESA astronaut to complete a long-duration mission in space. She set new records for longest single time in space for an ESA astronaut and female astronauts in general. She took over duties from ESA astronaut Alexander Gerst for cargo on ESA’s Automated Transfer Vehicle Georges Lemaître. Samantha was responsible for packing the versatile spacecraft. She monitored its undocking, which marked the end of an era – Georges Lemaître was the last in a series of five ATV vessels supplied by ESA to service the Station.
Samantha also helped to grab and dock two Dragon ferries with the Station’s robotic arm, providing support for the first in January and taking the lead as prime operator of the 16 m-long arm to grapple Dragon-6 in April.
With two spacewalks conducted during her mission, Samantha played an important role preparing her colleagues for their sortie and supporting them while they were working outside the Station.
Science foremost
For the first time a Station airlock was used for scientific research when Samantha and Terry sampled their exhaled breath under reduced pressure, using nitric oxide as a tool to monitor lung inflammation as well as charting lung health in astronauts.
Samantha’s Expedition saw much research conducted on genetics and biology, keeping ants, fruit flies, plants and worms for international studies on the effects of spaceflight over multiple generations.
Meanwhile, hardware attached to Europe’s Columbus laboratory module continues to monitor the Sun and ocean winds. Another exterior facility is exposing ‘extremophiles’ and organic compounds to space and investigating the origin of life.
ESA astronaut Samantha Cristoforetti, NASA astronaut Terry Virts and Russian commander Anton Shkaplerov landed safely on 11 June 2015 in the Kazakh steppe after a three-hour ride in their Soyuz spacecraft. They left the International Space Station at 10:20 GMT at the end of their six-month stay on the research complex.
Terry Virtz, Anton Shkaplerov, and Samantha Cristoforetti are returning after more than six months onboard the International Space Station where they served as members of the Expedition 42 and 43 crews.
Quelle: ESA

Tags: Raumfahrt 


Freitag, 12. Juni 2015 - 18:15 Uhr

Raumfahrt - Die vier RS-25-Triebwerke für den Debüt-Start des Space Launch System (SLS) sind Veteranen Space Shuttle Haupt Triebwerke (SSME)



The four RS-25 engines selected for the debut launch of the Space Launch System (SLS) are veteran Space Shuttle Main Engines (SSME) with a rich history of successful flight. The four engines will be delivered to the Michoud Assembly Facility in the second half of 2015, ahead of being installed on the core stage of the Exploration Mission -1 (EM-1) SLS.
SLS EM-1 Engine Set:
The RS-25D, or SSME as it is more commonly known, helped push the Space Shuttle fleet uphill during a 30 year career that resulted in only one major malfunction during its flight history - namely STS-51F (ME-1), resulting in a safe Abort To Orbit (ATO).
Following the decision to retire the Shuttle once the International Space Station had been assembled, the engines were set to live on with the Ares I Upper Stage. However, problems with the requirement for air-starting the engine for second stage flight altered NASA’s direction towards the J-2X.
With the Constellation Program (CxP) culled from NASA’s forward path, the realigned deep space exploration goals called for a Heavy Lift Launch Vehicle (HLV), utilizing the best hardware from the defunct CxP and esteemed Shuttle Program.
As such, the remaining set of RS-25Ds from the Shuttle Program were given one final role, to launch the SLS before ending their lives when the Core Stage is destroyed post-launch via a destructive re-entry.
A total of 15 RS-25Ds left the Kennedy Space Center (KSC) for their new role, arriving at the Stennis Space Center in 2012.
The shipped engines included all nine of the last SSMEs to fly with the Space Shuttle. These engines performed admirably, with Discovery flying Main Engine 1 (ME-1) – serial number 2044, ME-2 – 2048 and ME-3 – 2058 during her final mission, STS-133.
For Endeavour’s swansong, ME-1 – 2059, ME-2 – 2061, and ME-3 – 2057 helped begin the flight phase of the successful STS-134 mission, while Atlantis closed out the Space Shuttle Program, flying with engines ME-1 – 2047, ME-2 – 2060 and ME-3 – 2045 during STS-135.
In preparation for this new role for the famous engines, Stennis engineers built a new 7,755-pound thrust frame adapter for the A-1 Test Stand, in order to enable testing of the RS-25s ahead of their role on SLS’ core.
The first engine that will grace the test stand for the opening tests of the RS-25 for SLS will be Engine 0525.
This engine never flew in space, as it was one of two development engines used for component testing on Stand A-2 to support shuttle flights – 0528 was the second development engine.
Final testing – using these units was conducted in 2009 – with engine 0525 earmarked for any hot-fire tests that may have been required to support the final STS missions during 2010.
According to L2 information, the assembly of engine E0525 is now scheduled for completion on May 22.
The Firing Readiness Review for the A-1 test stand is scheduled for May 28, and engine E0525 is to be installed on the A-1 stand on June 2. The first test firing is still scheduled for July 8.
This will officially mark the first live testing of the RS-25s towards their role with SLS, as preparations for the December 15, 2017 debut of the HLV begin to pick up the pace.
In a sign of the advancing path towards that first launch, L2 information has confirmed NASA’s Liquid Engine Office has now selected the first four engines that will loft the monster rocket uphill.
The four engines – ME-2045, ME-2056, ME-2058, and ME-2060 – are all established Shuttle veterans with numerous successful missions under their belts.
Per L2 SSME Flight Readiness Review (FRR) and Green Book documentation, ME-2045 – the most experienced engine set to fly on EM-1 – flew on STS-89, 95, 92, 102 and 105 in its Block IIA configuration, along with STS-110, 113, 121, 118, 127, 131 – and the final shuttle mission with Atlantis on STS-135 – in its Block II configuration.
The upgrade path for the SSME saw the Block IIA as an intermediate upgrade from Block I, after which followed the full Block II configuration.  Changes made to the engines did not affect either the engine or the powerhead serial numbers.
The main change from Block IIA to Block II was the use of a new High Pressure Fuel Turbopump (HPFTP). However, there were also other changes made during this process, per the “SSME Bible” (L2).
In contrast, the Block I to Block IIA upgrade involved new engine serial numbers, such as the main combustion chamber, which was new. However, they were mated to the old powerheads, whose serial numbers did not change.
The next engine selected for EM-1 – ME-2056 – flew on STS-104 and 109 in its Block IIA, before becoming involved in STS-114 and STS-121 as a Block II engine.
ME-2058 and ME-2060 are newer engines, both flying only in their Block II configuration.
ME-2058  flew with STS-116, 120, 124, 119, 129 and 133, while ME-2060 helped push STS-127, 131 and STS-135 into orbit.
These four engines are scheduled to be delivered from their current home at the Stennis Space Center to MAF at one-month intervals beginning in September 2015.
SLS will see the engines being installed into the core at MAF, ahead of being shipped to the Kennedy Space Center (KSC).
After the last of those engines are delivered in December 2015, four more engines will be prepared and tested as contingency engines, to be available in case one or more of the first four engines need to be replaced.
These contingency engines will be ME-2047, ME-2059, ME-2062, and ME-2063.
Providing there are no problems with the EM-1 set, these next four engines are now all-but confirmed as being the engine set for SLS’ second mission into space, which may become a specific payload mission in 2019.
This intermediate mission may debut the new Exploration Upper Stage (EUS) ahead of SLS’ third mission, which is known as Exploration Mission -2 (EM-2).
EM-2 is set to be the first launch of a crewed Orion, on a mission to explore a captured asteroid near the Moon.
(Images: Via NASA and L2 content from L2′s SLS and SSME specific L2 sections, which includes, presentations, videos, graphics and internal – interactive with actual SLS engineers – updates on the SLS and HLV, available on no other site.)
(L2 is – as it has been for the past several years – providing full exclusive SLS and Exploration Planning coverage.
Quelle: NSC
Update: 12.06.2015

We have Ignition: NASA Space Launch System RS-25 Engine Fires Up for Third Test in Series

The RS-25 engine fires up at the beginning of a 500-second test June 11 at NASA's Stennis Space Center near Bay St. Louis, Mississippi. Four RS-25 engines will power the core stage of NASA's new rocket, the Space Launch System.
Credits: NASA/Stennis
Ladies and gentlemen, we've started our engine. An RS-25 engine fired up for 500 seconds June 11 at NASA's Stennis Space Center near Bay St. Louis, Mississippi.
Four RS-25 engines will power NASA's new rocket, the Space Launch System, at speeds of 17,500 mph -- 73 times faster than the top speeds of an Indianapolis 500 race car -- to send astronauts on future missions beyond Earth’s orbit, including to an asteroid and ultimately to Mars.
This is the third firing of an RS-25 development engine on the A-1 test stand at Stennis. The first RS-25 test in this series was conducted Jan. 9, and the second was May 28. Four more tests are planned for the current development engine.
"While we are using proven space shuttle hardware with these engines, SLS will have different performance requirements," said Steve Wofford, manager of the SLS Liquid Engines Office at NASA's Marshall Space Flight Center in Huntsville, Alabama. The Marshall Center manages the SLS Program for the agency. "That's why we are testing them again. This is a whole new ballgame -- we need way more power for these engines to be able to go farther than ever before when it comes to human exploration. And we believe the modifications we've made to these engines can do just that."
The first flight test of the SLS -- designated as Exploration Mission 1 -- will feature a configuration for a 70-metric-ton (77-ton) lift capacity and carry an uncrewed Orion spacecraft beyond low-Earth orbit to test the performance of the integrated system.
"We have several objectives that will be accomplished during this test series, which will provide critical data on the new engine controller unit, materials and engine propellant inlet pressure conditions," Wofford added.
The new engine controller unit, the "brain" of the engine, allows communication between the vehicle and the engine, relaying commands to the engine and transmitting data back to the vehicle. The controller also provides closed-loop management of the engine by regulating the thrust and fuel mixture ratio while monitoring the engine's health and status. The controller will use updated hardware and software configured to operate with the new SLS vehicle avionics architecture.
The test series will show how the RS-25 engines will perform with colder liquid oxygen temperatures; greater inlet pressure due to the taller SLS core stage liquid oxygen tank and higher vehicle acceleration; and more nozzle heating due to the four-engine configuration and its position in-plane with the SLS booster exhaust nozzles. New ablative insulation and heaters also will be tested during the series. Aerojet Rocketdyne of Sacramento, California, is the prime contractor for the RS-25 engine work.
As the SLS evolves, it will provide an unprecedented lift capability of 130 metric tons (143 tons) to enable missions even farther into our solar system to places like Mars.
Quelle: NASA


Freitag, 12. Juni 2015 - 08:45 Uhr

Raumfahrt - Rückkehr von ISS-Crew 43 am 11.Juni



ISS043E174193 (05/06/2015) --- NASA astronaut Terry Virts (left) Commander of Expedition 43 on the International Space Station along with crewmates Russian cosmonaut Anton Shkaplerov (center) and ESA (European Space Agency) astronaut Samantha Cristoforetti on May 6, 2015 perform a checkout of their Russian Soyuz spacesuits in preparation for the journey back to Earth.
Credits: NASA
After more than six months of performing scientific research and technology demonstrations in space, three International Space Station crew members are scheduled to depart the orbiting laboratory Thursday, June 11. NASA Television will provide coverage of their station departure and return to Earth.
Coverage begins at 10:40 a.m. EDT Wednesday, June 10, when Expedition 43 Commander Terry Virts of NASA hands over command of the space station to cosmonaut Gennady Padalka of the Russian Federal Space Agency (Roscosmos).
At 6:20 a.m. the following day, Virts and Flight Engineers Samantha Cristoforetti of ESA (European Space Agency) and Anton Shkaplerov of Roscosmos will undock their Soyuz spacecraft from the space station and land in Kazakhstan at 9:43 a.m. (7:43 p.m. Kazakh time).
Their return wraps up 199 days in space, during which they traveled more than 84 million miles since their launch from the Baikonur Cosmodrome in Kazakhstan on Nov. 24. Their return date was delayed four weeks to allow Roscosmos to investigate the cause of the loss of the unpiloted Progress 59 cargo ship in late April.
NASA Television will broadcast departure and landing activities at the following times:
Wednesday, June 10
10:40 a.m. - Change of command ceremony in which Virts hands over station command to Padalka
Thursday, June 11
2:30 a.m. - Farewell and hatch closure coverage (hatch closure scheduled for 2:55 a.m.)
6 a.m. - Undocking coverage (undocking scheduled at 6:20 a.m.)
8:30 a.m. - Deorbit burn and landing coverage (deorbit burn scheduled at 8:51 a.m., with landing at 9:43 a.m.)
noon. - Video File of hatch closure, undocking and landing activities
10 p.m. - Video File of landing and post-landing activities and post-landing interviews with Virts and Cristoforetti in Kazakhstan
When the Virts, Shkaplerov and Cristoforetti land in Kazakhstan Thursday, Virts will have logged 212 days in space on two flights, the first of which was on space shuttle mission STS-130 in 2010. Shkaplerov will have spent 364 days in space on two flights, the first of which was on Expedition 29/30 in 2011. This was Cristoforetti’s first flight into space.
Expedition 44 formally begins aboard the station, under the command of Padalka, when the Soyuz undocks. He and crewmates Scott Kelly of NASA and Mikhail Kornienko of Roscosmos will operate the station until the arrival of NASA astronaut Kjell Lindgren, Russian cosmonaut Oleg Kononenko and Kimiya Yui of the Japan Aerospace Exploration Agency, who are scheduled to launch from Kazakhstan in July.
Kelly and Kornienko are spending one year in space, twice the typical mission duration, to provide researchers the opportunity to learn more about the medical, psychological and biomedical challenges faced by astronauts during long duration spaceflight.
Quelle: NASA
Update: 11.06.2015

Expedition 43 Crew Departs Space Station, Lands Safely in Kazakhstan

The Soyuz TMA-15M crew, reviewing entry procedures in their descent module before returning to Earth on Thursday. Left to right: NASA astronaut Terry Virts, spacecraft commander Anton Shkaplerov and European Space Agency astronaut Samantha Cristoforetti. NASA

Ankunft von ISS-Crew-43 auf der Erde / Zhezkazgan, Kazakhstan 
Expedition 43 Commander Terry Virts of NASA, Flight Engineers Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos) and Samantha Cristoforetti of ESA (European Space Agency) touched down at 9:44 a.m. EDT (7:44 p.m., Kazakh time), southeast of the remote town of Dzhezkazgan in Kazakhstan.
Credits: NASA TV
Three crew members of the International Space Station (ISS) returned to Earth Thursday after a 199-day mission that included several spacewalks, technology demonstrations, and hundreds of scientific experiments spanning multiple disciplines, including human and plant biology.
Expedition 43 Commander Terry Virts of NASA, Flight Engineers Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos) and Samantha Cristoforetti of ESA (European Space Agency) touched down at 9:44 a.m. EDT (7:44 p.m., Kazakh time), southeast of the remote town of Dzhezkazgan in Kazakhstan.
During their time aboard the orbiting laboratory, the crew members participated in a variety of research activities focusing on the effects of microgravity on cells, Earth observation, physical science, and biological and molecular science. Their research included the start of a one-year study into human health management over long-duration space travel with the March arrival of NASA astronaut Scott Kelly and Roscosmos cosmonaut Mikhail Kornienko – the One-Year Crew.
team members welcomed three cargo spacecraft during their stay on station. One Russian ISS Progress cargo vehicle docked to the station in February carrying tons of supplies, and Virts assisted with grapple and connection of two SpaceX Dragon deliveries in January and April -- the company's fifth and sixth NASA-contracted commercial resupply missions.
In preparation for the arrival of U.S. commercial crew vehicles, Virts ventured outside the station for three planned spacewalks to make adjustments for new International Docking Adapters (IDA) that can accommodate the spacecraft. The first IDA is scheduled to arrive on SpaceX’s seventh commercial resupply flight later this month.
The crew also had the opportunity to participate in the demonstration of new, cutting-edge technologies such as the Synthetic Muscle experiment, a test of a new polymer that contracts and expands similar to real muscle. This technology has the potential for future use on robots, enabling them to perform tasks that require considerable dexterity but are too dangerous to be performed by humans in space.
The crew engaged in a number of biological studies, including one investigation to better understand the risks of in-flight infections and another studying the effects microgravity has on bone health during long-duration spaceflight. The Micro-5 study used a small roundworm and a microbe that causes food poisoning in humans to study the risk of infectious diseases in space, which is critical for ensuring crew health, safety and performance during long-duration missions. The Osteo-4 study investigated bone loss in space, which has applications not only for astronauts on long-duration missions, but also for people on Earth affected by osteoporosis and other bone disorders.
The returning crew members will celebrate individual milestones in their space exploration careers. With the completion of his second mission, Virts now has spent 212 days in space. Shkaplerov, having completed his second long-duration mission on the station, has spent 364 days in space. Cristoforetti set a new record for single mission duration by a female astronaut with 199 days in space on her first flight, surpassing NASA astronaut Suni Williams’ previous record of 195 days as a flight engineer on Expeditions 14 and 15 from December 2006 to June 2007.
Expedition 44 now is operating the station with Roscosmos’ Gennady Padalka in command. Flight Engineers Scott Kelly of NASA and Mikhail Kornienko of Roscosmos, are continuing station research and operations until three new crewmates arrive. Kelly and Kornienko are on the first joint U.S.-Russian one-year mission, an important stepping stone on NASA’s journey to Mars.
NASA’s Kjell Lindgren, Roscosmos’ Oleg Kononenko and Japan Aerospace Exploration Agency astronaut Kimiya Yui are scheduled to launch from Kazakhstan in late July.
Quelle: NASA
Update: 12.06.2015 

ISS crew successfully evacuated from descent capsule

The Mission Control Center specified that commander Shkaplerov was the first to be evacuated. Cristoforetti was the second and Virts the last one to be taken out
Members of a search and rescue group seen after finding a descent capsule in Kazakhstan in 2013© EPA/SHAMIL ZHUMATOV / POOL
KOROLYOV /Moscow Region/, June 11. /TASS/. Search and rescue groups have evacuated the astronauts, who returned to Earth from the International Space Station (ISS), from the descent capsule of the Soyuz TMA-15M spacecraft, the Moscow Region-based Mission Control Center said Thursday.
The descent capsule of the Soyuz TMA-15M manned spacecraft with three members of an international crew on board - Russian cosmonaut Anton Shkaplerov, American astronaut Terry Virts and European Space Agency astronaut Samantha Cristoforetti - landed at the estimated time in Kazakhstan.
The Mission Control Center specified that commander Shkaplerov was the first to be evacuated. Cristoforetti was the second and Virts the last one to be taken out.
The crew worked in orbit since late November 2014. The astronauts were to have returned May 14 but had to stay in orbit longer due to April’s accident involving the Progress M-27M spacecraft.
Russian cosmonauts Gennady Padalka and Mikhail Korniyenko, as well as NASA astronaut Scott Kelly remained on board the space station. The next manned spacecraft - Soyuz TMA-17M - will blast off toward the ISS July 24.
The Progress M-27M cargo spacecraft was launched on April 28 from the Baikonur space center on a Soyuz-2.1a carrier rocket. The rocket took the spacecraft to a higher orbit than required to dock with the ISS. After a few unsuccessful attempts to get control of the spacecraft, experts gave up the idea. The Progress was taking food, oxygen and other cargos to the ISS crew. It burned in dense atmosphere May 8.
Roscosmos concluded that the cause of the accident was "abnormal separation" of the Soyuz third stage and the Progress due to decompression of the rocket’s fuel tanks, caused by an unaccounted design property.
Quelle: TASS

After 199 Days in Orbit, Space Station Trio Comes Back Down to Earth

NASA's Terry Virts, Russia's Anton Shkaplerov and Italy's Samantha Cristoforetti sit in chairs outside their Soyuz spacecraft just minutes after landing in a remote area near the town of Zhezkazgan, Kazakhstan, on Thursday. Bill Ingalls / NASA
A NASA astronaut, a Russian cosmonaut and a record-setting Italian spaceflier left the International Space Station and landed back on Earth on Thursday after spending a longer-than-expected 199 days in orbit.
NASA's Terry Virts, Russia's Anton Shkaplerov and Italy's Samantha Cristoforetti sailed away in a Russian Soyuz space capsule right on time, at 6:20 a.m. ET, as part of a regular crew changeover. They touched down amid the steppes of Kazakhstan at 9:44 a.m. ET.
"It was a textbook homecoming," NASA commentator Rob Navias said.
After the landing, the three crew members were helped out of the capsule and set down in chairs to adjust to Earth's gravity. "I feel really good," Virts told the recovery team. "A cold water would be nice."
The spacefliers were taken to a medical tent for checkups, and within days they'll be back in their respective homes.
During the 199 days, Virts took part in three occasionally tense spacewalks to get the station ready for the arrival of U.S.-made spaceships a couple of years from now. The crew dealt with hundreds of scientific experiments, sipped the first espresso made in zero-G, and handled three robotic cargo deliveries — two by SpaceX Dragon capsules, and one by a Russian Progress craft.
The trio's return was delayed for nearly a month due to problems with a different Progress cargo ship in April. The craft was sent into a faulty orbit due to the failure of a Soyuz rocket and eventually burned up in Earth's atmosphere. The Russians didn't want to proceed with the station crew changeover until they finished investigating the mishap. Last week Russia launched its first Soyuz rocket since the failure.
The next three spacefliers are now scheduled to launch in another Soyuz capsule in late July.
The delay kept Cristoforetti in orbit long enough to set a space endurance record for women astronauts, surpassing the 195-day mark set by NASA's Sunita Williams in 2007. The record for male astronauts is 437.7 days, set by Soviet cosmonaut Valery Polyakov in 1995.
Three other astronauts remain on duty on the station: the outpost's new commander, Russian cosmonaut Gennady Padalka; and Russia's Mikhail Kornienko and NASA's Scott Kelly, who are in the midst of a nearly yearlong stay in orbit.
Quelle: BBC-News

Tags: Raumfahrt 


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