vendredi 30 décembre 2011

Happy New Year!












Orbiter.ch © Aerospace logo.


Dec. 30, 2011


A little personal message to wish a happy and successful year 2012 to all my Readers, Followers and Friends!

Orbiter.ch Aerospace, Software (add-ons for Orbiter Space Flight Simulator): http://orbiter.jimdo.com/

Orbiter.ch Aerospace, Daily: http://paper.li/Orbiter_ch/1306415282#

Happy New Year 2012! Best regards, Orbiter.ch

jeudi 29 décembre 2011

Fastest Rotating Star Found in Neighboring Galaxy









Astronomical Observatories discoveries.

Dec. 29, 2011


This artist's concept pictures the fastest rotating star found to date. The massive, bright young star, called VFTS 102, rotates at a million miles per hour, or 100 times faster than our sun does.

Centrifugal forces from this dizzying spin rate have flattened the star into an oblate shape and spun off a disk of hot plasma, seen edge on in this view from a hypothetical planet. The star may have "spun up" by accreting material from a binary companion star.

The rapidly evolving companion later exploded as a supernova. The whirling star lies 160,000 light-years away in the Large Magellanic Cloud, a satellite galaxy of the Milky Way.


Image above: VFTS 102, the fastest-rotating massive star. This view shows part of the stellar nursery called the Tarantula Nebula in the Large Magellanic Cloud, a small neighbor of the Milky Way.

The brilliant star VFTS 102 is in the center. This view includes both visible-light and infrared images from the Wide Field Imager at the MPG/ESO 2.2-meter telescope at La Silla, Chile and the 4.1-meter infrared VISTA telescope at Paranal, Chile. VFTS 102 is the most rapidly rotating massive star ever found.

Images, Text, Credits: NASA / ESA, and G. Bacon (STScI) / ESO / M.-R. Cioni / VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit.

Best regards, Orbiter.ch

mercredi 28 décembre 2011

Powerful Pixels: Mapping the "Apollo Zone"














NASA - Apollo All Missions commemorative patch / Google Earth logo.

Dec. 29, 2011

Grayscale pixels – up close, they look like black, white or grey squares. But when you zoom out to see the bigger picture, they can create a digital photograph, like this one of our moon:


Mosaic of the near side of the moon as taken by the Clementine star trackers. The images were taken on March 15, 1994. Credit: NASA

For NASA researchers, pixels are much more – they are precious data that help us understand where we came from, where we've been, and where we're going.

At NASA's Ames Research Center, Moffett Field, Calif., computer scientists have made a giant leap forward to pull as much information from imperfect static images as possible. With their advancement in image processing algorithms, the legacy data from the Apollo Metric Camera onboard Apollo 15, 16 and 17 can be transformed into an informative and immersive 3D mosaic map of a large and scientifically interesting part of the moon.

The "Apollo Zone" Digital Image Mosaic (DIM) and Digital Terrain Model (DTM) maps cover about 18 percent of the lunar surface at a resolution of 98 feet (30 meters) per pixel. The maps are the result of three years of work by the Intelligent Robotics Group (IRG) at NASA Ames, and are available to view through the NASA Lunar Mapping and Modeling Portal (LMMP) and Google Moon feature in Google Earth.

"The main challenge of the Apollo Zone project was that we had very old data – scans, not captured in digital format," said Ara Nefian, a senior scientist with the IRG and Carnegie Mellon University-Silicon Valley. "They were taken with the technology we had over 40 years ago with imprecise camera positions, orientations and exposure time by today’s standards."

The researchers overcame the challenge by developing new computer vision algorithms to automatically generate the 2D and 3D maps. Algorithms are sets of computer code that create a procedure for how to handle certain set processes. For example, part of the 2D imaging algorithms align many images taken from various positions with various exposure times into one seamless image mosaic. In the mosaic, areas in shadows, which show up as patches of dark or black pixels are automatically replaced by lighter gray pixels. These show more well-lit detail from other images of the same area to create a more detailed map.


Left: A normal one-camera image of the lunar surface. Right: A composite Apollo Zone image showing the best details from multiple photographs. Credit: NASA / Google Earth.

"The key innovation that we made was to create a fully automatic image mosaicking and terrain modeling software system for orbital imagery," said Terry Fong, director of IRG. "We have since released this software in several open-source libraries including Ames Stereo Pipeline, Neo-Geography Toolkit and NASA Vision Workbench."

Lunar imagery of varying coverage and resolution has been released for general use for some time. In 2009, the IRG helped Google develop "Moon in Google Earth", an interactive, 3D atlas of the moon. With "Moon in Google Earth", users can explore a virtual moonscape, including imagery captured by the Apollo, Clementine and Lunar Orbiter missions.

The Apollo Zone project uses imagery recently scanned at NASA's Johnson Space Center in Houston, Texas, by a team from Arizona State University. The source images themselves are large – 20,000 pixels by 20,000 pixels, and the IRG aligned and processed more than 4,000 of them. To process the maps, they used Ames' Pleiades supercomputer.

The initial goal of the project was to build large-scale image mosaics and terrain maps to support future lunar exploration. However, the project's progress will have long-lasting technological impacts on many targets of future exploration.


The color on this map represents the terrain elevation in the Apollo Zone mapped area. Credit: NASA / Google Earth.

"The algorithms are very complex, so they don't yet necessarily apply to things like real time robotics, but they are extremely precise and accurate," said Nefian. "It's a robust technological solution to deal with insufficient data, and qualities like this make it superb for future exploration, such as a reconnaissance or mapping mission to a Near Earth Object."

Near Earth Objects, or "NEOs" are comets and asteroids that have been attracted by the gravity of nearby planets into orbits in Earth's neighborhood. NEOs are often small and irregular, which makes their paths hard to predict. With these algorithms, even imperfect imagery of a NEO could be transformed into detailed 3D maps to help researchers better understand the shape of it, and how it might travel while in our neighborhood.

In the future, the team plans to expand the use of their algorithms to include imagery taken at angles, rather than just straight down at the surface. A technique called photoclinometry – or "shape from shading" – allows 3D terrain to be reconstructed from a single 2D image by comparing how surfaces sloping toward the sun appear brighter than areas that slope away from it. Also, the team will study imagery not just as pictures, but as physical models that give information about all the factors affect how the final image is depicted.

"As NASA continues to build technologies that will enable future robotic and human exploration, our researchers are looking for new and clever ways to get more out of the data we capture," said Victoria Friedensen, Joint Robotic Precursor Activities manager of the Human Exploration Operations Mission Directorate at NASA Headquarters. "This technology is going to have great benefit for us as we take the next steps."

This work was funded by NASA's LMMP, and supported by collaborators at NASA's Marshall Space Flight Center, Huntsville, Alabama, NASA's Goddard Space Flight Center, Greenbelt, Maryland, NASA's Jet Propulsion Laboratory, Pasadena, Calif. and the United States Geological Survey (USGS).

To view the maps, visit the LMMP site or view in Google Earth:

    Download Google Earth at: http://earth.google.com
    Click here to download a KML file for viewing in Google Earth:
    http://byss.ndc.nasa.gov/stereopipeline/dataviz/apollo_metric.kml
    Once you open that file in Google Earth you will have options to view these "Apollo Zone" maps overlaid on Google Earth's "Moon mode".

Related links:

LMMP: http://lmmp.nasa.gov/

Ames Stereo Pipeline: http://irg.arc.nasa.gov/ngt/stereo

Neo-Geography Toolkit: http://irg.arc.nasa.gov/ngt

NASA Vision Workbench: http://irg.arc.nasa.gov/nasa-vision-workbench

Open-source libraries: http://ti.arc.nasa.gov/opensource/

Images (mentioned), Text, Credit: NASA / Ames Research Center, Jessica Culler.

Cheers, Orbiter.ch

NASA Twin Spacecraft On Final Approach For Moon Orbit











NASA - GRAIL Mission patch.

Dec. 28, 2011

NASA's twin spacecraft to study the moon from crust to core are nearing their New Year's Eve and New Year's Day main-engine burns to place the duo in lunar orbit.

Named Gravity Recovery And Interior Laboratory (GRAIL), the spacecraft are scheduled to be placed in orbit beginning at 1:21 p.m. PST (4:21 p.m. EST) for GRAIL-A on Dec. 31, and 2:05 p.m. PST (5:05 p.m. EST) on Jan. 1 for GRAIL-B.

"Our team may not get to partake in a traditional New Year's celebration, but I expect seeing our two spacecraft safely in lunar orbit should give us all the excitement and feeling of euphoria anyone in this line of work would ever need," said David Lehman, project manager for GRAIL at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif.


Artist concept of GRAIL mission. GRAIL will fly twin spacecraft in tandem orbits around the moon to measure its gravity field in unprecedented detail. Image credit: NASA / JPL.

The distance from Earth to the moon is approximately 250,000 miles (402,336 kilometers). NASA's Apollo crews took about three days to travel to the moon. Launched from Cape Canaveral Air Force Station Sept. 10, 2011, the GRAIL spacecraft are taking about 30 times that long and covering more than 2.5 million miles (4 million kilometers) to get there.

This low-energy, long-duration trajectory has given mission planners and controllers more time to assess the spacecraft's health. The path also allowed a vital component of the spacecraft's single science instrument, the Ultra Stable Oscillator, to be continuously powered for several months. This will allow it to reach a stable operating temperature long before it begins making science measurements in lunar orbit.

"This mission will rewrite the textbooks on the evolution of the moon," said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT) in Cambridge. "Our two spacecraft are operating so well during their journey that we have performed a full test of our science instrument and confirmed the performance required to meet our science objectives."

As of Dec. 28, GRAIL-A is 65,860 miles (106,000 kilometers) from the moon and closing at a speed of 745 mph (1,200 kph). GRAIL-B is 79,540 miles (128,000 kilometers) from the moon and closing at a speed of 763 mph (1,228 kph).

During their final approaches to the moon, both orbiters move toward it from the south, flying nearly over the lunar south pole. The lunar orbit insertion burn for GRAIL-A will take approximately 40 minutes and change the spacecraft's velocity by about 427 mph (688 kph). GRAIL-B's insertion burn 25 hours later will last about 39 minutes and is expected to change the probe's velocity by 430 mph (691 kph).


Image above: Using a precision formation-flying technique, the twin GRAIL spacecraft will map the moon's gravity field, as depicted in this artist's rendering. detail. Image credit: NASA / JPL-Caltech.

The insertion maneuvers will place each orbiter into a near-polar, elliptical orbit with a period of 11.5 hours. Over the following weeks, the GRAIL team will execute a series of burns with each spacecraft to reduce their orbital period from 11.5 hours down to just under two hours. At the start of the science phase in March 2012, the two GRAILs will be in a near-polar, near-circular orbit with an altitude of about 34 miles (55 kilometers).

When science collection begins, the spacecraft will transmit radio signals precisely defining the distance between them as they orbit the moon. As they fly over areas of greater and lesser gravity, caused both by visible features such as mountains and craters and by masses hidden beneath the lunar surface. they will move slightly toward and away from each other. An instrument aboard each spacecraft will measure the changes in their relative velocity very precisely, and scientists will translate this information into a high-resolution map of the Moon's gravitational field. The data will allow mission scientists to understand what goes on below the surface. This information will increase our knowledge of how Earth and its rocky neighbors in the inner solar system developed into the diverse worlds we see today.

JPL manages the GRAIL mission. MIT is home to the mission's principal investigator, Maria Zuber. The GRAIL mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

For more information about GRAIL, visit: http://www.nasa.gov/grail

Images, Text, Credit: NASA / JPL-Caltech.

Cheers, Orbiter.ch

Orange and Blue Hazes









NASA / ESA - Cassini Insider's logo.

Dec. 28, 2011


This view from NASA's Cassini spacecraft looks toward the south polar region of Saturn's largest moon, Titan, and shows a depression within the moon's orange and blue haze layers near the south pole.

The moon's high altitude haze layer appears blue here; whereas, the main atmospheric haze is orange. The difference in color could be due to particle size of the haze. The blue haze likely consists of smaller particles than the orange haze.

The depressed or attenuated layer appears in the transition area between the orange and blue hazes about a third of the way in from the left edge of the narrow-angle image. The moon's south pole is in the upper right of this image. This view suggests Titan's north polar vortex, or hood, is beginning to flip from north to south.

The southern pole of Titan is going into darkness as the sun advances towards the north with each passing day. The upper layer of Titan's hazes is still illuminated by sunlight.

Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained on Sept. 11, 2011 at a distance of approximately 83,000 miles (134,000 kilometers) from Titan. Image scale is 2,581 feet (787 meters) per pixel.

More information about Cassini mission is online at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov

Images, Text, Credit: NASA / JPL-Caltech / Space Science Institute.

Greetings, Orbiter.ch

Spacecraft Globalstar-2 displayed on the target orbit











ROSCOSMOS patch.

28/12/2011

 Soyuz-2.1a with Globalstar satellites ready for the launch

December 28 at 21.09 Moscow time from Launch Complex 31 area Baikonur starting the automatedcalculations of rocket Soyuz, space industry of Russia conducted a successful launch of space rocket (ILV) "Soyuz-2.1a" with the upper block (RB) "Frigate" and a cluster of six spacecraft (SC) "Globalstar-2."

video
Soyuz-2.1a launch

After regular office from the third stage rocket head unit in the Republic of Belarus "Frigate" satellites and six went on autonomous flight.

In accordance with cyclogram removal from spacecraft launch cyclogram cleanly separated from the upper stage and handed over control to the customer.

Globalstar-2 satellite

Relay satellite "Globalstar-2" developed by «Thales Alenia Space» commissioned by the corporation "Globalstar» (Globalstar) and are designed to provide high quality services to global personal mobile communication.

In October 2010 and July 2011. from the Baikonur Cosmodrome launch successfully completed similar clusters of 6 spacecraft "Globalstar-2."

Original text in Russian: http://www.federalspace.ru/main.php?id=2&nid=18523

Images, Video, Text, Credits: Press Service of the Russian Space Agency (Roscosmos PAO) / Thales-Alenia / Arianespace / Translation: Orbiter.ch.

Greetings, Orbiter.ch

mardi 27 décembre 2011

Ring of Fire











NASA - Chandra X-ray Observatory patch.

Dec. 27, 2011


This composite image shows the central region of the spiral galaxy NGC 4151. X-rays (blue) from the Chandra X-ray Observatory are combined with optical data (yellow) showing positively charged hydrogen (H II) from observations with the 1-meter Jacobus Kapteyn Telescope on La Palma. The red ring shows neutral hydrogen detected by radio observations with the NSF's Very Large Array. This neutral hydrogen is part of a structure near the center of NGC 4151 that has been distorted by gravitational interactions with the rest of the galaxy, and includes material falling towards the center of the galaxy. The yellow blobs around the red ellipse are regions where star formation has recently occurred.

A recent study shows the X-ray emission probably was caused by an outburst powered by the supermassive black hole located in the white region in the center of the galaxy. Evidence for this idea comes from the elongation of the X-rays running from the top left to the bottom right and details of the X-ray spectrum. There are also signs of interactions between a central source and the surrounding gas, particularly the yellow arc of H II emission located above and to the left of the black hole.

NGC 4151 is located about 43 million light years away from the Earth and is one of the nearest galaxies that contains an actively growing black hole. Because of this proximity, it offers one of the best chances of studying the interaction between an active supermassive black hole and the surrounding gas of its host galaxy. Such interaction, or feedback, is recognized to play a key role in the growth of supermassive black holes and their host galaxies. If the X-ray emission in NGC 4151 originates from hot gas heated by the outflow from the central black hole, it would be strong evidence for feedback from active black holes to the surrounding gas on galaxy scales. This would resemble the larger scale feedback, observed on galaxy cluster scales, from active black holes interacting with the surrounding gas, as seen in objects like the Perseus Cluster.

Chandra X-ray Observatory

These results were published in the Aug. 20, 2010 issue of The Astrophysical Journal Letters. The authors were Junfeng Wang and Giuseppina Fabbiano from the Harvard Smithsonian Center for Astrophysics (CfA); Guido Risaliti from CfA and INAF-Arcetri Observatory, in Firenze, Italy; Martin Elvis from CfA; Carole Mundell from Liverpool John Moores University in Birkenhead, UK; Gaelle Dumas and Eva Schinnerer from the Max Planck Institute for Astrophysics in Heidelberg, Germany; and, Andreas Zezas from CfA and the University of Crete in Greece.

For more information about Chandra X-ray Observatory, visit: http://www.nasa.gov/mission_pages/chandra/main/index.html and http://cxc.harvard.edu/

Images, Text, Credits: X-ray: NASA / CXC / CfA / J.Wang et al.; Optical: Isaac Newton Group of Telescopes, La Palma / Jacobus Kapteyn Telescope, Radio: NSF / NRAO / VLA.

Best regards, Orbiter.ch

dimanche 25 décembre 2011

Debris from the Soyuz at the origin of a luminous trail over Europe












Space Junk.

Dec. 25, 2011

Luminous trail over Europe

The remains of a Russian Soyuz rocket are the source of the trail of light observed during Christmas Eve in a part of the European sky, said Sunday the Royal Observatory of Belgium. She was immediately aroused curiosity and questions, the Soyuz launch failed on Friday 23 December (launch of the Meridian military communications satellite).

"The ball that was observed on December 24 around 17:30 over Belgium, the Netherlands, France and Germany, was the start of the last stage of the Soyuz launcher that comes to transport including the astronaut André Kuipers' to the ISS, International Space Station, said Sunday Observatory of Belgium.

A ball of light, followed by a long trail and not looking like a shooting star, was seen Saturday in the evening in several parts of Germany, in southern Belgium and northern France in particular.
Mystery lifted Sunday.

video
Soyuz debris over Germany

Videos showing this strange trail moving for about 30 seconds before disappearing were broadcast on the internet and the Center for UFO exploration of Mannheim, in the south-west Germany, was inundated with phone calls. Some experts initially estimated that this could be a meteorite.

The mystery was finally lifted by Sunday Observatory of Belgium for the events related to the failure of a Russian rocket. A Soyuz has indeed taken off Wednesday from the Baikonur Cosmodrome in Kazakhstan, to the ISS but suffered a breakdown on board, which prevented the orbit of a satellite communications military and civilian.

Soyuz 2-1b rocket lifts off  on Dec. 23, from the Plesetsk Cosmodrome in northern Russia

"A failure occurred on the third stage of the rocket at the 421st second flight" had acknowledged Friday the Russian Ministry of Defense. The result also observed the luminous trail in European airspace Saturday, a fragment of the satellite fell to Earth Friday, crashing into the roof of a house in Siberia, according to Russian authorities.


Ironically, it crashed on the roof of a house in the street of the Cosmonauts, in a village in Siberia.

This is a sphere of 50cm diameter, police said, who has not said if people were in the building. This fragment belonged to the Soyuz third stage during the launch of the Meridian military communications satellite whose orbit failed aboard the Soyuz on Friday.

This is the fifth failure in 33 launches from the least January.

Text, Images, Video, Credit: ATS / AFP / Orbiter.ch / Translation: Orbiter.ch.

Best regards and Happy Holidays, Orbiter.ch

vendredi 23 décembre 2011

Festival of Lights









NASA - Wide-field Infrared Survey Explorer (WISE) patch.

Dec. 23, 2011


WISE, NASA's Wide-field Infrared Survey Explorer, has a new view of Barnard 3, or IRAS Ring G159.6-18.5, that is awash in bright green and red dust clouds. Interstellar clouds like these are stellar nurseries, where baby stars are being born.

The green ring is made of tiny particles of warm dust whose composition is very similar to smog found here on Earth. The red cloud in the center is most likely made of dust that is more metallic and cooler than the surrounding regions. HD 278942, the bright star in the middle of the red cloud, is so luminous that it is the likely cause of the surrounding ring's glow. The bright greenish-yellow region left of center is similar to the ring, though more dense. The bluish-white stars scattered throughout are stars located both in front of, and behind, the nebula.

Wide-field Infrared Survey Explorer (WISE)

Regions similar to this nebula are found near the band of the Milky Way galaxy in the night sky. This nebulas is slightly off this band, near the boundary between the constellations of Perseus and Taurus, but at a relatively close distance of only about 1,000 light-years, the cloud is a still part of our Milky Way.

The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.

For more information about WISE, visit: http://www.nasa.gov/mission_pages/WISE/main/index.html

Images, Text, Credit: NASA / JPL-Caltech / UCLA.

Cheers, Orbiter.ch

Cosmonaut and Astronaut's arrives at the Space Station

 












ROSCOSMOS - Soyuz TMA-03M Mission patch / ESA - PromISSe Mission patch.

23 December 2011

ESA astronaut André Kuipers and crewmates Oleg Kononeko and Don Pettit docked today with the International Space Station in their Soyuz TMA-03M spacecraft. They will work aboard the Station now for five months and return to Earth in May.

ESA’s fourth long mission on the International Space Station began on Wednesday, when the Soyuz rocket roared into the evening sky from Baikonur Cosmodrome in Kazakhstan.

video
Approaching the Space Station

After circling the globe for the last two days, the spacecraft docked at 13:43 GMT (14:43 CET) this evening, 23 December.

The automated rendezvous sequence began about two hours before docking, but the crew, led by commander Oleg Kononenko, were ready to take over manually if required.

A routine arrival

Preparing for arrival, the crew closed the hatch between the two Soyuz modules, donned their Sokol pressure suits and carefully monitored the approach and docking sequence.

View to the Soyuz spacecraft after the launch

Soyuz slowly flew around the Station and spiralled in to perfect alignment with the Earth-facing docking port of Russia’s Zarya module.

With TV cameras transmitting views of the Station, Soyuz fired its small thrusters for the final approach.

After docking, a firm connection is being confirmed and, when pressure checks found no air leaks, the crew will remove their suits. The hatch to the Station will be opened after the pressure is equalised between the two vehicles.

Mission full of PromISSe

During his mission, PromISSe, André will conduct more than 25 ESA experiments and around 20 for NASA and Japan’s space agency, JAXA, including human research, biology, fluid physics, materials science, radiation research and technology.

Soyuz liftoff on Wednesday

His mission also features a strong educational aspect centred on the theme ‘Spaceship Earth’.

The lessons from space will educate children in science, technology, engineering and mathematics, as well as illustrating the requirements for life on Earth.

As part of ‘Mission-X: Train Like an Astronaut’, André will invite thousands of students to perform physical exercises and classroom lessons to compete with teams around the world to become as fit as astronauts.

Greeting audience at the launch pad

Following his mission is easy: André is tweeting on @astro_andre and writing his own mission diary in Dutch (‘Logboek’) with English translations.

The PromISSe blog covers the whole mission and it’s also an ideal way to post questions and comments.

For more information about the mission, take a look at http://www.esa.int/promisse.

Related links:

@astro_andre: https://twitter.com/astro_andre

Mission diary in Dutch: http://blogs.esa.int/andre-kuipers

English translations: http://blogs.esa.int/andre-kuipers/?lang=en

PromISSe blog: http://blogs.esa.int/promisse

ISS Expedition 30 (NASA): http://www.nasa.gov/mission_pages/station/expeditions/expedition30/index.html

ISS Expedition 31 (NASA): http://www.nasa.gov/mission_pages/station/expeditions/expedition31/index.html

Roscosmos (Russia): http://roscosmos.ru/main.php

Ruimteschip Aarde: http://www.ruimteschipaarde.nl/

Images, Video, Text, Credits: ESA, S. Corvaja / ROSCOSMOS / ROSCOSMOS TV / NASA TV / Youtube.

Greetings, Orbiter.ch

jeudi 22 décembre 2011

NASA's Cassini Delivers Holiday Treats From Saturn












NASA - Cassini Mission to Saturn patch.

Dec. 22, 2011


Image above: Saturn's third-largest moon Dione can be seen through the haze of its largest moon, Titan, in this view of the two posing before the planet and its rings from NASA's Cassini spacecraft. Image credit: NASA / JPL-Caltech / Space Science Institute.

No team of reindeer, but radio signals flying clear across the solar system from NASA's Cassini spacecraft have delivered a holiday package of glorious images. The pictures, from Cassini's imaging team, show Saturn's largest, most colorful ornament, Titan, and other icy baubles in orbit around this splendid planet. The release includes images of satellite conjunctions in which one moon passes in front of or behind another. Cassini scientists regularly make these observations to study the ever-changing orbits of the planet's moons. But even in these routine images, the Saturnian system shines. A few of Saturn's stark, airless, icy moons appear to dangle next to the orange orb of Titan, the only moon in the solar system with a substantial atmosphere. Titan's atmosphere is of great interest because of its similarities to the atmosphere believed to exist long ago on the early Earth.

The images are online at: http://www.nasa.gov/cassini, http://saturn.jpl.nasa.gov and http://ciclops.org .


Image above: The colorful globe of Saturn's largest moon, Titan, passes in front of the planet and its rings in this true color snapshot from NASA's Cassini spacecraft. Image credit: NASA / JPL-Caltech / Space Science Institute.

While it may be wintry in Earth's northern hemisphere, it is currently northern spring in the Saturnian system and it will remain so for several Earth years. Current plans to extend the Cassini mission through 2017 will supply a continued bounty of scientifically rewarding and majestic views of Saturn and its moons and rings, as spectators are treated to the passage of northern spring and the arrival of summer in May 2017.

"As another year traveling this magnificent sector of our solar system draws to a close, all of us on Cassini wish all of you a very happy and peaceful holiday season, " said Carolyn Porco, Cassini imaging team lead at the Space Science Institute, Boulder, Colo.


Image above: Saturn's moon Tethys, with its stark white icy surface, peeps out from behind the larger, hazy, colorful Titan in this Cassini view of the two moons. Image credit: NASA / JPL-Caltech / Space Science Institute.

More information about Cassini mission is online at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .

Cassini spacecraft. Credit: NASA / JPL

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo.

Images (mentioned), Text, Credits: NASA / JPL / Jia-Rui Cook / Space Science Institute / Joe Mason.

Best regards, Orbiter.ch

NASA Telescopes Help Find Rare Galaxy at Dawn of Time














NASA - SPITZER Space Telescope patch / NASA & ESA - Hubble Space Telescope patch.

Dec. 22, 2011


This image shows one of the most distant galaxies known, called GN-108036, dating back to 750 million years after the Big Bang that created our universe. Image credit: NASA / JPL-Caltech / STScI / University of Tokyo.

Astronomers using NASA's Spitzer and Hubble space telescopes have discovered that one of the most distant galaxies known is churning out stars at a shockingly high rate. The blob-shaped galaxy, called GN-108036, is the brightest galaxy found to date at such great distances.

The galaxy, which was discovered and confirmed using ground-based telescopes, is 12.9 billion light-years away. Data from Spitzer and Hubble were used to measure the galaxy's high star production rate, equivalent to about 100 suns per year. For reference, our Milky Way galaxy is about five times larger and 100 times more massive than GN-108036, but makes roughly 30 times fewer stars per year.

"The discovery is surprising because previous surveys had not found galaxies this bright so early in the history of the universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "Perhaps those surveys were just too small to find galaxies like GN-108036. It may be a special, rare object that we just happened to catch during an extreme burst of star formation."

The international team of astronomers, led by Masami Ouchi of the University of Tokyo, Japan, first identified the remote galaxy after scanning a large patch of sky with the Subaru Telescope atop Mauna Kea in Hawaii. Its great distance was then carefully confirmed with the W.M. Keck Observatory, also on Mauna Kea.

 SPITZER Space Telescope. Credit: NASA.

"We checked our results on three different occasions over two years, and each time confirmed the previous measurement," said Yoshiaki Ono of the University of Tokyo, lead author of a new paper reporting the findings in the Astrophysical Journal.

GN-108036 lies near the very beginning of time itself, a mere 750 million years after our universe was created 13.7 billion years ago in an explosive "Big Bang." Its light has taken 12.9 billion years to reach us, so we are seeing it as it existed in the very distant past.

Astronomers refer to the object's distance by a number called its "redshift," which relates to how much its light has stretched to longer, redder wavelengths due to the expansion of the universe. Objects with larger redshifts are farther away and are seen further back in time. GN-108036 has a redshift of 7.2. Only a handful of galaxies have confirmed redshifts greater than 7, and only two of these have been reported to be more distant than GN-108036.

 Hubble Space Telescope. Credit: NASA / ESA

Infrared observations from Spitzer and Hubble were crucial for measuring the galaxy's star-formation activity. Astronomers were surprised to see such a large burst of star formation because the galaxy is so small and from such an early cosmic era. Back when galaxies were first forming, in the first few hundreds of millions of years after the Big Bang, they were much smaller than they are today, having yet to bulk up in mass.

During this epoch, as the universe expanded and cooled after its explosive start, hydrogen atoms permeating the cosmos formed a thick fog that was opaque to ultraviolet light. This period, before the first stars and galaxies had formed and illuminated the universe, is referred to as the "dark ages." The era came to an end when light from the earliest galaxies burned through, or "ionized," the opaque gas, causing it to become transparent. Galaxies similar to GN-108036 may have played an important role in this event.

"The high rate of star formation found for GN-108036 implies that it was rapidly building up its mass some 750 million years after the Big Bang, when the universe was only about five percent of its present age," said Bahram Mobasher, a team member from the University of California, Riverside. "This was therefore a likely ancestor of massive and evolved galaxies seen today."

Other authors include: Kyle Penner and Benjamin J. Weiner of the University of Arizona, Tucson; Kazuhiro Shimasaku and Kimihiko Nakajima of the University of Tokyo; Jeyhan S. Kartaltepe of the National Optical Astronomy Observatory; Hooshang Nayyeri of the University of California, Riverside; Daniel Stern of NASA's Jet Propulsion Laboratory, Pasadena, Calif.; Nobunari Kashikawa of the National Astronomical Observatory of Japan; and Hyron Spinrad of University of California, Berkeley.

NASA / ESA Hubble Space Telescope. 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. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu/ and http://www.nasa.gov/spitzer .

Images (mentioned), Text, Credit: NASA / ESA / JPL / Whitney Clavin.

Greetings, Orbiter.ch

CryoSat ice satellite rides new waves







ESA - CRYOSAT 2 Mission logo.

22 December 2011

ESA’s CryoSat mission has been gathering detailed information on the thickness of Earth’s ice since its launch in 2010. Through international collaboration, this state-of-the-art mission is soon to be used to monitor conditions at sea for marine forecasting.

CryoSat was built to measure tiny variations in the thickness of Earth’s ice. As a result, the mission is providing scientists with the data they need to help improve our understanding of the relationship between ice, climate and sea level.

Wind speed from CryoSat

As CryoSat orbits from pole to pole, it passes over vast expanses of ocean. So while the mission was designed specifically for ice monitoring, it can also serve to help improve the safety of marine traffic. 

The satellite carries Europe’s first radar altimeter specialised for the purpose of detecting tiny variations in the height of the ice – but it can also be used to measure sea level and the height of the waves.

The instrument sends out short radar pulses and measures the time it takes for the signals to travel from the satellite to the ground and back. This information provides the height of the surface below.

video
CryoSat in orbit

The advantage of yielding this kind of information from CryoSat is also down to the advanced performance of its main SIRAL instrument.

When data from CryoSat are merged with other altimeter data such as that from the Envisat and Jason satellites, the combined estimation of wave height and wind speed is greatly improved.

In addition, thanks to its drifting orbit, CryoSat allows a high number of crossovers with other altimeter missions. This provides a set of measurements that have not been available before.

Marine weather forecasts are essential for the safe passage of vessels but accurate forecasts need a supply of timely wind and wave observations.

Since CryoSat’s primary objective was measure ice, fast data delivery was not initially intended.

Wave height from CryoSat

However, the CryoSat team has changed this to demonstrate that CryoSat can deliver marine information in near-real time from most of its orbits around Earth.

Up to now, this new product called 'fast delivery mode' has only been provided to organisations such the National Ocean and Atmospheric Organisation (NOAA) in the US.

This is about to change: marine information is expected to be available systematically to all users from February.

At NOAA’s Laboratory for Satellite Altimetry (LSA), the CryoSat data are processed to estimate wind speed and wave height, which are then provided to forecasters at NOAA’s National Centres for Environmental Predication.

CryoSat is also providing data on sea level. This is important for monitoring the movement of the ocean waters and mapping the heat content of the upper layers – a reservoir of energy that can lead to tropical storms and hurricanes.

Sea level from CryoSat and other satellites

LSA combines CryoSat data with information from other organisations such as the French space agency CNES, the European Centre for Medium-Range Weather Forecasts and NASA.

This processing takes a matter of only three days. NOAA delivers these data to ocean modellers and forecasters worldwide.

For example, Australia’s Integrated Marine Observing System now uses CryoSat observations of sea level to monitor surface currents.

This is not only a prime example of what an international approach can achieve in Earth observation, but also demonstrates that although ESA’s family of Earth Explorer satellites are designed with a specific scientific objective in mind, they are able to offer so much more – benefiting both science and the way we live.

Related links:

CryoSat: http://www.esa.int/SPECIALS/Cryosat/index.html

Access CryoSat data: http://earth.esa.int/cryosat

In depth, CryoSat-2: http://www.esa.int/esaLP/LPcryosat.html

NOAA: http://www.noaa.gov/

CSIRO Marine and Atmospheric Research: http://www.cmar.csiro.au/

IMOS Integrated Marine Observing System: http://imos.org.au/

Images, Video, Text, Credits: Credits: ESA / AOES Medialab / NOAA, E. Leuliette, J. Sienkiewicz / CSIRO, D. Griffen.

Best regards, Orbiter.ch

First Galileo satellite producing full spectrum of signals












ESA - GALILEO / GIOVE Mission logo.

22 December 2011

Europe’s first Galileo satellite appears in blooming health, transmitting test signals received by ESA’s ground station in Redu, Belgium across the whole of its assigned radio spectrum.

The first two Galileo satellites were launched by Soyuz from Europe’s Spaceport in French Guiana on 21 October. They are currently in the midst of a rigorous campaign to check that their highly sophisticated navigation payloads are operating as planned, unaffected by the strains of launch.

Galileo team at Redu receiving signals

Testing is centred on the first Galileo satellite for now, expected to progress to the second satellite early in the new year.

Galileo is a state-of-the-art global satellite navigation system offering various groups of users a total of ten different modulated signals across three spectral bands, known as E1, E5 and E6. 

Last weekend all Galileo signals were activated simultaneously across these bands for the first time, following the switch-on and ‘outgassing’ – warming up to vent potentially harmful vapours – of power amplifiers in the remaining E6 band.

First Galileo triple band signals

The signals were received by Galileo Test User Receivers deployed at the Redu ground station, within Belgium’s Ardennes forest, as well as by identical receivers at ESA’s Navigation Laboratory, in ESA’s ESTEC technical centre in Noordwijk, the Netherlands.

These test receivers work in the same way as operational receivers will once Galileo begins its initial services in 2014. They are capable of processing the Open Service, Commercial Service and Safety-of-Life Service signals from the Galileo constellation.

First two Galileo IOV satellites

Galileo combines multi-frequency signals with the most accurate atomic clock ever flown in space for navigation, accurate to one second in three million years. Its signals should open up a large number of commercial applications by combining this accuracy with the increased reliability of dual- or triple-frequency measurements.

Receiver developers can choose among the variety of Galileo signals on offer to meet the needs of their customers in the most efficient way. They can even combine the processing of Galileo signals with US GPS or Russian Glonass signals to offer more robust positioning information in challenging environments such as city centre ‘urban canyons’.

Related Links:

Soyuz-Galileo IOV launch website: http://www.esa.int/SPECIALS/Galileo_IOV/

Navigation: http://www.esa.int/esaNA/index.html

Galileo: http://www.esa.int/esaNA/galileo.html

Redu Centre: http://www.esa.int/SPECIALS/About_ESA/SEM4UQJ4LOG_0.html

Images, Text, Credits: ESA / P. Carril.

Greetings, Orbiter.ch