samedi 29 novembre 2014

Laser link offers high-speed delivery










ESA - Sentinel-1 Mission logo / ESA - Alphasat Mission logo.

29 November 2014

Marking a first in space, Sentinel-1A and Alphasat have linked up by laser stretching almost 36 000 km across space to deliver images of Earth just moments after they were captured.

Sentinel-1A

This important step demonstrates the potential of Europe’s new space data highway to relay large volumes of data very quickly so that information from Earth-observing missions can be even more readily available.

Alphasat

Having timely access to imagery from the Sentinel-1 mission, for example, is essential for numerous applications such as maritime safety and helping to respond to natural disasters.

video
Linking to EDRS for continual data delivery

Orbiting from pole to pole about 700 km up, Sentinel-1A transmits data to Earth routinely, but only when it passes over its ground stations in Europe. However, geostationary satellites, hovering 36 000 km above Earth, have their ground stations in permanent view so they can stream data to Earth all the time.

This takes a great deal of coordination between the different teams working intensively. Later on, in routine operations, this will be fully automated.

Creating a link between the two kinds of satellites means that more information can be streamed to Earth, and almost continuously. Engineers have turned to laser to accomplish this.

Berlin from Sentinel-1A via laser

Funded by ESA and the DLR German Aerospace Center, Tesat has developed a laser communications terminal and downlink system that is carried on the geostationary Alphasat, Europe’s largest telecommunications satellite. This novel unit’s counterpart is flying on Sentinel-1A.

Over the past few weeks the Sentinel-1A operations teams at ESA’s European Space Operations Centre, ESOC, in Darmstadt, Germany, and ESA’s Earth Observation Centre, ESRIN, in Frascati, Italy, and German Space Operations Center, GSOC, in Oberpfaffenhofen, Germany, have been working intensively to prepare for the first laser link tests.

The image on the right, showing Berlin in Germany, is one of the first images delivered using this state-of-the-art technology.

“Demonstrating laser data link-ups in space has involved excellent teamwork by many at ESA, Inmarsat, Tesat and DLR,” says ESA’s Head of Mission Operations, Paolo Ferri.

EDRS–Sentinel-1A event

“I am especially proud of the major contribution the operations teams at ESOC and ESRIN have provided to the success of this activity, which will significantly improve data availability from Earth observation missions and enhance benefits for all citizens in the future.”

Heads of various agencies gathered at ESOC today to follow the operators as they linked the two satellites by laser. Radar data over Asia were acquired and downlink to Earth in near-real time.

Magali Vaissiere, ESA’s Director of Telecommunications and Integrated Applications, said, “Today, space systems have become part of the global Big Data challenge.

“You can visualise the link of today as an optical fibre in the sky that can connect the Sentinels back home to Europe, from wherever they are on their orbit around Earth.

The gold standard for EDRS

“The link is operated at 1.8 Gbit/s, with a design that could scale up to 7.2 Gbit/s in the future. Never has so much data travelled in space.”

Following processing by ESA’s Copernicus Ground Segment, images will be online and available to the public through the Sentinel data website: https://sentinel.esa.int/web/sentinel/home

Philippe Goudy, Head of ESA’s Earth Observation Projects Department, said, “This laser link between the two satellites marks an important milestone in efforts to further ensure that the Copernicus environmental services are fed with large volumes of data that are not only accurate, but are also provided as quickly as possible.

“By improving the availability of Copernicus information and services, EDRS will help to unleash the economic potential of Copernicus and thus give a boost to the overall economy.”

As today’s events show, this precursor to the future European Data Relay System (EDRS) has paved the way for an entirely new approach of delivering data.

Gerd Gruppe, DLR Member of the Executive Board Space Administration, added, “This technology has been fostered by DLR for more than 20 years. Today, laser communication technology allows a transmission of 2.7 million full written pages per minute. That’s why we have to establish this technology as a standard of communication.

video
EDRS

“Space laser communication is the future!”

The first EDRS element will be carried on the Eutelsat-9B satellite, launched next year. In the meantime, Sentinel-1A will now be able to connect through the precursor laser terminal on Alphasat. Sentinel-2A, scheduled for launch next spring, also carries the same payload.

Both Sentinel missions are dedicated to delivering key information for Europe’s environmental monitoring Copernicus programme.

Related links:

EDRS: http://www.esa.int/Our_Activities/Telecommunications_Integrated_Applications/EDRS

Sentinel-1: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1

Operations: http://www.esa.int/Our_Activities/Operations

DLR: http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10002/

Teasat Spacecom: http://www.tesat.de/en/

Inmarsat: http://www.inmarsat.com/

Airbus Defence and Space: http://www.space-airbusds.com/de/

European Commission Copernicus site: http://www.copernicus.eu/

Images, Videos, Text, Credits: ESA/J. Mai/Copernicus data/Airbus Defence and Space SAS/ATG medialab.

Greetings, Orbiter.ch

jeudi 27 novembre 2014

Venus Express rises again












ESA - Venus Express Mission patch.

November 27, 2014

Between 23 and 30 November the operations team at ESOC will conduct manoeuvres to raise the pericentre of the Venus Express (VEX) orbit again, in an effort to keep the spacecraft in productive orbit around Venus.


Image above: Visualisation of Venus Express during  aerobraking manoeuvre in 2014. The altitude of the orbit will now be raised back up, allowing science investigations to continue into 2015. Image Credits: ESA/C. Carreau.

These manoeuvres could be the last  for VEX due to low propellant levels, but all being well, VEX will continue its valuable scientific observations into 2015. The question is: how much longer can the spacecraft operate?

Venus Express has been in a reduced science phase since its orbit was changed following the hugely successful aerobraking campaign during the summer of 2014. The mission, originally planned for two-plus-two (two years nominal operation with a two-year extension) years, has been successfully collecting critical science data from the ‘Morning Star’ for over eight years now.

“This has been a fantastic mission and a great achievement for science over the last eight years and Venus Express continues to return excellent scientific data,” states Håkan Svedhem, Venus Express Project Scientist.

“The spacecraft remains healthy after this year’s demanding aerobraking campaign and return to scientific productivity, and we’re looking forward to getting as much science as possible while the fuel lasts.”

Lifting the orbit

Due to a combination of effects from the gravity of Venus and our Sun, VEX’s closest point of approach, the pericentre, is constantly descending closer to Venus. This ‘decay’ of the pericentre altitude would eventually damage the spacecraft (due to drag) if it is not raised away from the atmosphere.

The OCMs taking place now are using the spacecraft’s thrusters to lift the satellite at controlled increments back to a safer orbit. Without them, the pericentre altitude falls around 3 to 5 km per day.

Visualisation of Venus Express during  aerobraking manoeuvre. Image Credits: ESA/C. Carreau

As a result of the successful aerobraking manoeuvres earlier this year, the nominal 24-hr orbital period has been reduced to just over 22 hrs. Given that the routine flight control procedures followed for the last eight years – science planning, observations, ground station passes, reaction wheel offloading – were designed for a 24-hr orbit, the change of orbital period by nearly two hours has affected many aspects of planning and operations for the flight control team.

“It’s increasingly demanding to fly the spacecraft during this reduced science phase due to the changed orbit,” says Adam Williams, acting Spacecraft Operations Manager of Venus Express at ESOC.

“For most of our mission, we had a very regular 24-hour orbit. Now, we’re in a 22-hour orbit and this results in varying periods for science and ground station passes, so our operations tempo is much more irregular and very demanding.”

Correcting orbital decay

The OCMs scheduled for this month will correct the natural decay that has occurred since the PRM (pericentre raising manoeuvres) conducted in July, after the aerobraking activity.

“Aerobraking was very successful in July. It’s a credit to the designers that we have such a robust spacecraft capable of these demanding manoeuvres, and to the operators that they have kept it working so well. The mission has continued for much longer than its planned nominal lifetime and will likely continue even further,” explains Patrick Martin, Venus Express Mission Manager.

video
Venus Express aerobraking

Video above: Visualisation of the first Venus Express aerobraking manoeuvre, which will see the spacecraft orbiting Venus at an altitude of around 130 km from 18 June to 11 July. In the month before, the altitude will gradually be reduced from around 200 km to 130 km. If the spacecraft survives and fuel permits, the elevation of the orbit will be raised back up to approximately 450 km, allowing operations to continue for a further few months. Eventually, however, the spacecraft will plunge back into the atmosphere and the mission will end. Video Credits: ESA/C.Carreau.

Adding to the challenge, the team won’t know if each manoeuvre has been successful until the following day’s communications pass. In one case, they will have to wait two days for their telemetry to return due to ground station availability constraints.

How much fuel do we have?

Everything now hangs on the amount of fuel and oxidiser on board the spacecraft.

It is calculated that there is around 3 kg of fuel and 5 kg of oxidiser remaining, although some of this may not be usable due to movement of propellant in the tanks. Estimates indicate around 1.4 kg of fuel and 2 kg of oxidiser are needed for the manoeuvres.

However, it’s impossible to be certain just how much propellant is actually available and the mission’s continuation into 2015 has been approved on the assumption that propellant remains available.

Whatever happens, once the fuel is exhausted, this hugely successful mission will come to a natural end.

A monumental mission

The Venus Express mission has observed Venus for over eight years and returned startling and amazing data from Earth’s nearest planetary neighbour. Observations have focused on the structure, dynamics, composition and chemistry of the dense atmosphere and overlying clouds. VEX also investigated the swirling vortex at the planet’s south pole.

Venus Express  discovered Venus’ surprisingly cold region high in the planet’s atmosphere, and the high-altitude ozone layer. The mission confirmed that Venus is losing water from its upper atmosphere and that it may have been much more humid and Earth-like.


Image above: Andrea Accomazzo, 3rd from right, Venus Express Spacecraft Operations Manager, and members of the Venus Express mission control team anxiously await confirmation of orbit entry in ESOC's Main Control Room, 11 April 2006. Credit: ESA/J. Mai.

Some observations of the surface terrain were possible with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS). The data provide the best evidence to date that Venus has been volcanically active in recent geological times. In the upper atmosphere, large variations of sulphur dioxide have been discovered.

Toward the end of an era

Venus Express continues going strong, generating valuable scientific data, and is expected to continue to do so in robust health into 2015. The satellite itself is in excellent condition, as are all its functional instruments.

"It is a bit sad to know that sooner or later the spacecraft will run out of propellant," says ESA's Andrea Accomazzo, Head of the Solar and Planetary Missions Division at ESOC and the first Venus Express Spacecraft Operations Manager.

"When we launched Venus Express, nobody thought it would last this long. This spacecraft has been operating in a very demanding environment for many years;  with this mission we could capitalise and consolidate our early experiences with Rosetta and Mars Express. This all contributed to the now very well established capability at ESA to conceive and operate interplanetary missions.”

“Venus Express is, after Rosetta and Mars Express, the most recently launched of ESA’s interplanetary jewels. It was supposed to be a short mission, but the robustness of the spacecraft and the skills of our operations and flight dynamics teams have made it a much longer lasting, incredibly successful mission,” says Paolo Ferri, Head of Mission Operations.

“Its mission at Venus has been not only a major scientific achievement, but also very important for our teams to gain experience in operating a probe so close to the Sun. This will be extremely useful also for the preparation of the upcoming BepiColombo mission to Mercury.”

Access more information on the discoveries of the mission here: http://sci.esa.int/venus-express/33010-summary/

Related articles:

Venus Express gets ready to take the plunge: http://orbiterchspacenews.blogspot.ch/2014/05/venus-express-gets-ready-to-take-plunge.html

Venus Express: up above the clouds so high: http://orbiterchspacenews.blogspot.ch/2014/07/venus-express-up-above-clouds-so-high.html

Venus Express rise again: http://orbiterchspacenews.blogspot.ch/2014/07/venus-express-rise-again.html

Related links:

Venus Express Mission: http://www.esa.int/Our_Activities/Space_Science/Venus_Express

Images (mentioned), Video (mentioned), Text, Credits: ESA.

Greetings, Orbiter.ch

Frost-covered chaos on Mars












ESA - Mars Express Mission patch.

27 November 2014

Hellas Chaos

Thanks to a break in the dusty ‘weather’ over the giant Hellas Basin at the beginning of this year, ESA’s Mars Express was able to look down into the seven kilometre-deep basin and onto the frosty surface of Hellas Chaos.

Hellas Basin sits in the southern highlands of Mars and is one of the Solar System’s largest impact basins, with a diameter of 2300 km. It is thought to have formed some 3.8–4.1 billion years ago, during the heavy bombardment that subjected all the inner Solar System planets to a heavy rain of asteroids and comets.

Since its formation, Hellas has been sculpted by wind, ice, water and volcanic activity. It is also where most global dust storms on Mars originate.

Hellas Chaos in context

The region presented here, known as Hellas Chaos, lies in the southern central part of the basin. The high-resolution stereo camera on Mars Express captured it on 23 January.

Much of the scene is dusted with carbon dioxide frost, although in places the underlying surface is exposed. In contrast to the frosty terrain, the ridges running through the centre of the image appear golden, probably from the low Sun angle of around 25°. Flows of sediments are also visible on some portions of their flanks.

Trough in Hellas Chaos

Immediately to the north (right) of the ridges, the elevation drops down into a large east–west trough (best seen in the topography map), the floor of which displays many small knobs with a rough surface.

To the right again, the curved outline of large sublimation pits can be seen, interspersed with polygonal-patterned terrain. These features develop as a result of the contraction and relaxation during freeze–thaw cycles as the seasons change.

A few distinct impact craters can also be seen in this scene. For example, at the bottom right, one with a layered rim exhibits some dark internal streaks that could be dunes shaped by prevailing winds.

Hellas Chaos topography

In the top-right corner, a large flat-topped ‘mesa’ rises from the surface. The flanks of the mesa are covered with dust that seems to flow down into the surrounding depression. Here, the material is pushed together, presumably from successive flows producing parallel ridges of piled sediment layers.

Smaller craters can also be seen in the right-hand part of the image, some with debris blankets that appear fluidised, indicating the presence of subsurface ice that melted during the impacts that created the craters.

In the left-hand portion of the image, there are also two large, noteworthy features. At the lower left, there appear to be the remains of two overlapping craters, with the eroded rim of the smaller one sitting inside a larger crater. Both display eroded walls and host interesting internal features.

Meanwhile, in the top-left corner of the image, a region of lower elevation is littered by curious ridges and blocks of material that exhibit the same rough textures as the knobs in the central part of the image.

Hellas Chaos in 3D

The origin of the Hellas Chaos region in general is widely debated. One idea is that large amounts of sediments were deposited inside the Hellas Basin and later eroded by wind and water.

Another idea suggests that volcanic activity might be the cause. The context map shows extensive lava flows around the ‘chaos’, perhaps related to the nearby volcano Amphitrites Patera.

Alternatively, floods of lava inside the Hellas Basin, following the formation of the basin itself, could have given rise to the structures seen in this region today.

Related links:

Looking at Mars: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Mars Express overview: http://www.esa.int/Our_Activities/Space_Science/Mars_Express_overview

Mars Express 10 year brochure: http://esamultimedia.esa.int/multimedia/publications/BR-312/

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens...: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Behind_the_lens

Frequently asked questions: http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Frequently_asked_questions

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

Mars Express blog: http://blogs.esa.int/mex/

Mars Webcam: http://blogs.esa.int/vmc

Images, Text, Credits: ESA/DLR/FU Berlin.

Greetings, Orbiter.ch

mercredi 26 novembre 2014

High-flying Turkey on Station Crew’s Thanksgiving Menu










ISS - Expedition 42 Mission patch.

November 26, 2014

The International Space Station is operating at full capacity as the six-member Expedition 42 crew ramps up new science experiments by setting up research hardware.

Commander Barry Wilmore partnered up with new Flight Engineer Terry Virts in Japan’s Kibo laboratory module setting up a nanosatellite deployer known as Cyclops. Wilmore then moved on to science freezer maintenance while Virts worked on the Aniso Tubule botany study and measured air velocity in Kibo.


Image above: The Kibo laboratory module, where the Cyclops nanosatellite deployer is being prepared for service, is seen from a camera on the International Space Station. Credit: NASA TV.

Read more about the Cyclops nanosatellite launcher: http://www.nasa.gov/mission_pages/station/research/experiments/1014.html

Read more about Aniso Tubule: http://www.nasa.gov/mission_pages/station/research/experiments/1013.html

Italian astronaut Samantha Cristoforetti on her first space mission set up gear for the Blind and Imagined experiment that observes visual and sensory changes in crew members on long-duration space missions. The three cosmonauts worked on a variety of Russian science experiments including the study of the cardiovascular system, radiation exposure in the station and plasma research.

Read more about Blind and Imagined: http://www.nasa.gov/mission_pages/station/research/experiments/127.html

The NASA astronauts on the orbital complex will have a light day on Thursday for the Thanksgiving holiday and will share a meal with the rest of their crewmates.

The six International Space Station crew members, in orbit 260 miles above Earth, will enjoy a somewhat traditional Thanksgiving dinner but with a few tweaks.

While most Americans are roasting turkeys and emptying cranberry sauce out of cans, the station crew will be cutting open bags of freeze-dried, irradiated and thermostabilized foods.

Their menu will include traditional holiday fare with a space-food flair — irradiated smoked turkey, thermostabilized candied yams and freeze-dried green beans and mushrooms. The meal also will feature NASA’s own freeze-dried cornbread dressing — just add water. Dessert features thermostabilized cherry-blueberry cobbler.


Image above: Commander Barry Wilmore talks about what he’s grateful for, gives thanks to the military for their service and reveals what he and Expedition 42 crew are eating on Thanksgiving. Watch his video message. Image Credit: NASA TV.

The space station Expedition 42 crew is made up of Commander Barry “Butch” Wilmore of NASA, Flight Engineer Terry Virts of NASA, Flight Engineers Anton Shkaplerov, Alexander Samokutyaev and Elena Serova of Russia’s Roscosmos and Italian Flight Engineer Samantha Cristoforetti of the European Space Agency.

Station food generally resembles that, for the most part, flown in space since the inception of the Space Shuttle Program some 30 years ago. NASA is researching and developing ways to extend the shelf-life of food needed for deep space missions, such as those to Mars, and to minimize the volume of packaging. The agency also is using the International Space Station as a laboratory to learn how to grow plants, such as lettuce, in space.

Future crew members spending Thanksgiving in space may have one traditional staple, fresh sweet potatoes. The sweet potato may be one of the crops chosen for crews to grow on deep space missions. It provides an important energy source — carbohydrate — as well as beta-carotene.

video
Thanksgiving Feast on Orbit

Video above: NASA Commentator Pat Ryan talks with International Space Station Food System Manager Vickie Kloeris about the types of food that are prepared for crews on orbit and the selections available for the Expedition 42 Thanksgiving celebration. Video Credit: NASA TV.

The sweet potato is able to adapt to a controlled environment with artificial sunlight. It is highly adaptable to a variety of vine-training architectures. The main shoot tip, or the end of the main vine, is the only really sensitive part. It sends hormones throughout the plant that stimulate root development, which is important since it is the roots that become the sweet potatoes. The side shoots, if picked when young, are tender and can be eaten in salads, improving the plant’s usefulness.

Scientists believe most food items in the transit food system on future deep space missions will resemble those used on the station. Advanced processing and packaging methods will be needed to provide extended shelf lives and improved nutrition for the longer missions. Stored food and salad crops will be used in the early stages of planetary stays until permanent living bases are constructed.

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video (mentioned), Text, Credit: NASA.

Cheers, Orbiter.ch

NASA's Van Allen Probes Spot an Impenetrable Barrier in Space










NASA - Van Allen Probes Mission patch.

November 26, 2014

Two donuts of seething radiation that surround Earth, called the Van Allen radiation belts, have been found to contain a nearly impenetrable barrier that prevents the fastest, most energetic electrons from reaching Earth.


Image above: A cloud of cold, charged gas around Earth, called the plasmasphere and seen here in purple, interacts with the particles in Earth's radiation belts — shown in grey— to create an impenetrable barrier that blocks the fastest electrons from moving in closer to our planet. Image Credit: NASA/Goddard.

The Van Allen belts are a collection of charged particles, gathered in place by Earth’s magnetic field. They can wax and wane in response to incoming energy from the sun, sometimes swelling up enough to expose satellites in low-Earth orbit to damaging radiation. The discovery of the drain that acts as a barrier within the belts was made using NASA's Van Allen Probes, launched in August 2012 to study the region. A paper on these results appeared in the Nov. 27, 2014, issue of Nature magazine.

“This barrier for the ultra-fast electrons is a remarkable feature of the belts," said Dan Baker, a space scientist at the University of Colorado in Boulder and first author of the paper. "We're able to study it for the first time, because we never had such accurate measurements of these high-energy electrons before."

Understanding what gives the radiation belts their shape and what can affect the way they swell or shrink helps scientists predict the onset of those changes. Such predictions can help scientists protect satellites in the area from the radiation.

The Van Allen belts were the first discovery of the space age, measured with the launch of a US satellite, Explorer 1, in 1958. In the decades since, scientists have learned that the size of the two belts can change – or merge, or even separate into three belts occasionally. But generally the inner belt stretches from 400 to 6,000 miles above Earth's surface and the outer belt stretches from 8,400 to 36,000 miles above Earth's surface.

A slot of fairly empty space typically separates the belts. But, what keeps them separate? Why is there a region in between the belts with no electrons?

Enter the newly discovered barrier. The Van Allen Probes data show that the inner edge of the outer belt is, in fact, highly pronounced. For the fastest, highest-energy electrons, this edge is a sharp boundary that, under normal circumstances, the electrons simply cannot penetrate.

"When you look at really energetic electrons, they can only come to within a certain distance from Earth," said Shri Kanekal, the deputy mission scientist for the Van Allen Probes at NASA's Goddard Space Flight Center in Greenbelt, Maryland and a co-author on the Nature paper. "This is completely new. We certainly didn't expect that."

The team looked at possible causes. They determined that human-generated transmissions were not the cause of the barrier. They also looked at physical causes. Could the very shape of the magnetic field surrounding Earth cause the boundary? Scientists studied but eliminated that possibility. What about the presence of other space particles? This appears to be a more likely cause.


Animation above: This animated gif shows how particles move through Earth’s radiation belts, the large donuts around Earth. The sphere in the middle shows a cloud of colder material called the plasmasphere. New research shows that the plasmasphere helps keep fast electrons from the radiation belts away from Earth. Image Credit: NASA/Goddard/Scientific Visualization Studio.

The radiation belts are not the only particle structures surrounding Earth. A giant cloud of relatively cool, charged particles called the plasmasphere fills the outermost region of Earth's atmosphere, beginning at about 600 miles up and extending partially into the outer Van Allen belt. The particles at the outer boundary of the plasmasphere cause particles in the outer radiation belt to scatter, removing them from the belt.

This scattering effect is fairly weak and might not be enough to keep the electrons at the boundary in place, except for a quirk of geometry: The radiation belt electrons move incredibly quickly, but not toward Earth. Instead, they move in giant loops around Earth. The Van Allen Probes data show that in the direction toward Earth, the most energetic electrons have very little motion at all – just a gentle, slow drift that occurs over the course of months. This is a movement so slow and weak that it can be rebuffed by the scattering caused by the plasmasphere.

video
Radiation Belts & Plasmapause

Video above: Visualisation of the radiation belts with confined charged particles (blue & yellow) and plasmapause boundary (blue-green surface). Video Credit: NASA's Scientific Visualization Studio.

This also helps explain why – under extreme conditions, when an especially strong solar wind or a giant solar eruption such as a coronal mass ejection sends clouds of material into near-Earth space – the electrons from the outer belt can be pushed into the usually-empty slot region between the belts.

"The scattering due to the plasmapause is strong enough to create a wall at the inner edge of the outer Van Allen Belt," said Baker. "But a strong solar wind event causes the plasmasphere boundary to move inward."

A massive inflow of matter from the sun can erode the outer plasmasphere, moving its boundaries inward and allowing electrons from the radiation belts the room to move further inward too.

The Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, built and operates the Van Allen Probes for NASA's Science Mission Directorate. The mission is the second in NASA's Living With a Star program, managed by Goddard.

For more information about the Van Allen Probe, visit: http://www.nasa.gov/vanallenprobes

Image & Animation (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Karen C. Fox.

Greetings, Orbiter.ch

A Colourful Gathering of Middle-aged Stars












ESO - European Southern Observatory logo.

26 November 2014

The colourful star cluster NGC 3532

The MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile has captured a richly colourful view of the bright star cluster NGC 3532. Some of the stars still shine with a hot bluish colour, but many of the more massive ones have become red giants and glow with a rich orange hue.

The location of the bright star cluster NGC 3532 in the constellation of Carina

NGC 3532 is a bright open cluster located some 1300 light-years away in the constellation of Carina (The Keel of the ship Argo). It is informally known as the Wishing Well Cluster, as it resembles scattered silver coins which have been dropped into a well. It is also referred to as the Football Cluster, although how appropriate this is depends on which side of the Atlantic you live. It acquired the name because of its oval shape, which citizens of rugby-playing nations might see as resembling a rugby ball.

Wide-field view of the sky around the bright star cluster NGC 3532

This very bright star cluster is easily seen with the naked eye from the southern hemisphere. It was discovered by French astronomer Nicolas Louis de Lacaille whilst observing from South Africa in 1752 and was catalogued three years later in 1755. It is one of the most spectacular open star clusters in the whole sky.

NGC 3532 covers an area of the sky that is almost twice the size of the full Moon. It was described as a binary-rich cluster by John Herschel who observed “several elegant double stars” here during his stay in southern Africa in the 1830s. Of additional, much more recent, historical relevance, NGC 3532 was the first target to be observed by the NASA/ESA Hubble Space Telescope, on 20 May 1990.

video
Zooming in on the colourful star cluster NGC 3532

This grouping of stars is about 300 million years old. This makes it middle-aged by open star cluster standards [1]. The cluster stars that started off with moderate masses are still shining brightly with blue-white colours, but the more massive ones have already exhausted their supplies of hydrogen fuel and have become red giant stars. As a result the cluster appears rich in both blue and orange stars. The most massive stars in the original cluster will have already run through their brief but brilliant lives and exploded as supernovae long ago. There are also numerous less conspicuous fainter stars of lower mass that have longer lives and shine with yellow or red hues. NGC 3532 consists of around 400 stars in total.

video
Panning across the colourful star cluster NGC 3532

The background sky here in a rich part of the Milky Way is very crowded with stars. Some glowing red gas is also apparent, as well as subtle lanes of dust that block the view of more distant stars. These are probably not connected to the cluster itself, which is old enough to have cleared away any material in its surroundings long ago.

This image of NGC 3532 was captured by the Wide Field Imager instrument at ESO’s La Silla Observatory in February 2013.

Notes:

[1] Stars with masses many times greater than the Sun have lives of just a few million years, the Sun is expected to live for about ten billion years and low-mass stars have expected lives of hundreds of billions of years — much greater than the current age of the Universe.

More information:

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Photos of the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=mpg

Other photos taken with the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=15

Photos of La Silla: http://www.eso.org/public/images/archive/category/lasilla/

Images, Text, Credits: ESO/G. Beccari/IAU and Sky & Telescope/Digitized Sky Survey 2. Acknowledgement: Davide De Martin/Videos: ESO/G. Baccari/Digitized Sky Survey 2/N. Risinger (skysurvey.org). Music: movetwo.

Best regards, Orbiter.ch

mardi 25 novembre 2014

Beams come knocking on the LHC's door












CERN - European Organization for Nuclear Research logo.

November 25, 2014

Over the weekend, proton beams came knocking on the Large Hadron Collider's (LHC) door. Shooting from the Super Proton Synchrotron (SPS) and into the two LHC injection lines, the proton beams were stopped just short of entering the accelerator.

Although the actual physics run will not start until 2015, the LHC Operations team used these tests to check their control systems, beam instrumentation, transfer line alignment, perform the first optics measurements and to spot possible bottle necks in the beam trajectory. Furthermore, the ALICE and LHCb experiments could calibrate their detectors.


Image above: Transverse beam profile in the LHC injection lines (TI2 left, TI8 right).

"These initial tests are a milestone for the whole accelerator chain," says Reyes Alemany Fernandez, the engineer in charge of the LHC. "Not only was this the first time the injection lines have seen beams in over a year, it was also our first opportunity to test the LHC's operation system. We successfully commissioned the LHC's injection and ejection magnets, all without beam in the machine itself."

Just before entering the LHC, the beams were stopped by 21.6 tonnes of graphite, aluminium and copper "beam dumps" that absorb the accelerated particles. Offshoot particles - primarily muons - generated during the dump were in turn used to calibrate ALICE and LHCb. "The experiments where given the precise timing of each beam dump, which allowed them to tune their detectors and trigger to the LHC clock," says Verena Kain, SPS supervisor.

Following these successful extraction tests, the Operations team return to their preparations for the next run of the LHC. The first LHC tests with beams are scheduled for February 2015.

CERN announces LHC restart schedule: http://orbiterchspacenews.blogspot.ch/2014/06/cern-announces-lhc-restart-schedule.html

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 20 Member States.

Read more:

"The proton beam knocks at the LHC door" – Update by the LHCb experiment collaboration: http://lhcb-public.web.cern.ch/lhcb-public/Welcome.html#TED

Related links:

Large Hadron Collider's (LHC): http://home.web.cern.ch/about/accelerators/large-hadron-collider

Super Proton Synchrotron (SPS): http://home.web.cern.ch/about/accelerators/super-proton-synchrotron

ALICE: http://home.web.cern.ch/about/experiments/alice

LHCb: http://home.web.cern.ch/about/experiments/lhcb

Image, Text, Credits: CERN/Katarina Anthony.

Greetings, Orbiter.ch

CERN makes public first data of LHC experiments












CERN - European Organization for Nuclear Research logo.

November 25, 2014

CERN launched its Open Data Portal where data from real collision events, produced by experiments at the Large Hadron Collider (LHC) will for the first time be made openly available to all. It is expected that these data will be of high value for the research community, and also be used for education purposes.

"Launching the CERN Open Data Portal is an important step for our Organization. Data from the LHC programme are among the most precious assets of the LHC experiments, that today we start sharing openly with the world. We hope these open data will support and inspire the global research community, including students and citizen scientists," says CERN Director-General Rolf Heuer.

The principle of openness is enshrined in CERN’s founding Convention, and all LHC publications have been published Open Access, free for all to read and re-use. Widening the scope, the LHC collaborations recently approved Open Data policies and will release collision data over the coming years.

The first high-level and analysable collision data openly released come from the CMS experiment and were originally collected in 2010 during the first LHC run. This data set is now publicly available on the CERN Open Data Portal. Open source software to read and analyse the data is also available, together with the corresponding documentation. The CMS collaboration is committed to releasing its data three years after collection, after they have been thoroughly studied by the collaboration.


Image above: The web-based CMS event display, accessible through the CERN Open Data Portal, shows a proton-collision event recorded by the CMS detector. Image Credits: CMS/Open Data Portal.

“This is all new and we are curious to see how the data will be re-used,” says CMS data preservation coordinator Kati Lassila-Perini. “We’ve prepared tools and examples of different levels of complexity from simplified analysis to ready-to-use online applications. We hope these examples will stimulate the creativity of external users.”

In parallel, the CERN Open Data Portal gives access to additional event data sets from the ALICE, ATLAS, CMS and LHCb collaborations, which have been specifically prepared for educational purposes, such as the international masterclasses in particle physics benefiting over ten thousand high-school students every year. These resources are accompanied by visualisation tools.

“Our own data policy foresees data preservation and its sharing. We have seen that students are fascinated by being able to analyse LHC data in the past and so, we are very happy to take the first steps and make available some selected data for education” says Silvia Amerio, data preservation coordinator of the LHCb experiment.

“The development of this Open Data Portal represents a first milestone in our mission to serve our users in preserving and sharing their research materials. It will ensure that the data and tools can be accessed and used, now and in the future,” says Tim Smith of the CERN IT Department.

All data on OpenData.cern.ch are shared under a Creative Commons CC0 public domain dedication; data and software are assigned unique DOI identifiers to make them citable in scientific articles; and software is released under open source licenses. The CERN Open Data Portal is built on the open-source Invenio Digital Library software, which powers other CERN Open Science tools and initiatives.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 20 Member States.

Read more:

"On the road to open science" – Opinion piece by Tim Smith of the CERN IT department: http://home.web.cern.ch/cern-people/opinion/2014/11/road-open-science

Further information:

Open Data Portal: http://opendata.cern.ch/

Open data policies: http://opendata.cern.ch/collection/data-policies

CMS Open Data: http://cms.web.cern.ch/news/first-batch-lhc-open-data-cms-released

Related links:

Large Hadron Collider (LHC): http://home.web.cern.ch/topics/large-hadron-collider

ALICE: http://home.web.cern.ch/about/experiments/alice

ATLAS: http://home.web.cern.ch/about/experiments/atlas

LHCb: http://home.web.cern.ch/about/experiments/lhcb

Image, Text, Credits: CERN/Cian O'Luanaigh.

Cheers, Orbiter.ch

ISS 3-D printer - Made in Space












ISS - International Space Station patch.

November 25, 2014

Open for Business: 3-D Printer Creates First Object in Space on International Space Station

The International Space Station’s 3-D printer has manufactured the first 3-D printed object in space, paving the way to future long-term space expeditions.

"This first print is the initial step toward providing an on-demand machine shop capability away from Earth," said Niki Werkheiser, project manager for the International Space Station 3-D Printer at NASA's Marshall Space Flight Center in Huntsville, Alabama. "The space station is the only laboratory where we can fully test this technology in space.”


Image above: International Space Station Commander Barry “Butch” Wilmore holds up the first object made in space with additive manufacturing or 3-D printing. Wilmore installed the printer on Nov. 17, 2014, and helped crews on the ground with the first print on Nov. 25, 2014. Image Credit: NASA.

NASA astronaut Barry "Butch" Wilmore, Expedition 42 commander aboard the International Space Station, installed the printer on Nov. 17 and conducted the first calibration test print. Based on the test print results, the ground control team sent commands to realign the printer and printed a second calibration test on Nov. 20. These tests verified that the printer was ready for manufacturing operations. On Nov. 24, ground controllers sent the printer the command to make the first printed part: a faceplate of the extruder’s casing. This demonstrated that the printer can make replacement parts for itself. The 3-D printer uses a process formally known as additive manufacturing to heat a relatively low-temperature plastic filament and extrude it one layer at a time to build the part defined in the design file sent to the machine.

On the morning of Nov. 25, Wilmore removed the part from the printer and inspected it. Part adhesion on the tray was stronger than anticipated, which could mean layer bonding is different in microgravity, a question the team will investigate as future parts are printed. Wilmore installed a new print tray, and the ground team sent a command to fine-tune the printer alignment and printed a third calibration coupon. When Wilmore removes the calibration coupon, the ground team will be able to command the printer to make a second object. The ground team makes precise adjustments before every print, and the results from this first print are contributing to a better understanding about the parameters to use when 3-D printing on the space station.

“This is the first time we’ve ever used a 3-D printer in space, and we are learning, even from these initial operations,” Werkheiser said. “As we print more parts we’ll be able to learn whether some of the effects we are seeing are caused by microgravity or just part of the normal fine-tuning process for printing. When we get the parts back on Earth, we’ll be able to do a more detailed analysis to find out how they compare to parts printed on Earth.”

The 3-D Printing in Zero-G Technology Demonstration on the space station aims to show additive manufacturing can make a variety of 3-D printed parts and tools in space. The first object 3-D printed in space, the printhead faceplate, is engraved with names of the organizations that collaborated on this space station technology demonstration: NASA and Made In Space, Inc., the space manufacturing company that worked with NASA to design, build and test the 3-D printer. Made In Space is located on the campus of NASA’s Ames Research Center in Moffett Field, California.

video
Setting up a Machine Shop in Space

Video above: Niki Werkheiser, the International Space Station 3-D printer project manager at NASA’s Marshall Space Flight Center in Huntsville, Alabama, discusses the on-orbit set-up and first test run of the International Space Station’s 3-D Printer. Image Credit: NASA.

“We chose this part to print first because, after all, if we are going to have 3-D printers make spare and replacement parts for critical items in space, we have to be able to make spare parts for the printers,” Werkheiser said. “If a printer is critical for explorers, it must be capable of replicating its own parts, so that it can keep working during longer journeys to places like Mars or an asteroid. Ultimately, one day, a printer may even be able to print another printer.”

Made In Space engineers commanded the printer to make the first object while working with controllers at NASA’s Payload Operations Integration Center in Huntsville. As the first objects are printed, NASA and Made In Space engineers are monitoring the manufacturing via downlinked images and videos. The majority of the printing process is controlled from the ground to limit crew time required for operations.

"The operation of the 3-D printer is a transformative moment in space development," said Aaron Kemmer, chief executive officer of Made In Space. "We’ve built a machine that will provide us with research data needed to develop future 3-D printers for the International Space Station and beyond, revolutionizing space manufacturing. This may change how we approach getting replacement tools and parts to the space station crew, allowing them to be less reliant on supply missions from Earth."

The first objects built in space will be returned to Earth in 2015 for detailed analysis and comparison to identical ground control samples made on the flight printer after final flight testing earlier this year at, NASA’s Marshall Center prior to launch. The goal of this analysis is to verify that the 3-D printing process works the same in microgravity as it does on Earth.

Related link:

3-D Printing in Zero-G Technology Demonstration: http://www.nasa.gov/mission_pages/station/research/experiments/1115.html

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Video (mentioned), Text, Credits: NASA's Marshall Space Flight Center/Bill Hubscher.

Greetings, Orbiter.ch

Unprecedented Simulations of Galaxy Formation











NASA logo.

November 25, 2014

Understanding the formation of galaxies like our own Milky Way, and the tiny dwarf galaxies around it, is key to furthering our understanding of how cosmic structures formed and the nature of dark matter and black holes. To follow the formation of even one galaxy over the lifetime of the universe requires an accurate physical model that includes many different processes which act on both large and small scales.

A new code, ChaNGA, is being run on NASA high-performance computers to produce realistic galaxy simulations that capture gravity and gas hydrodynamics, and describe how stars form and die and how black holes evolve. The simulations resolve galaxy structures at unprecedented resolution—down to several hundred light years (about 100 parsecs).

video

Video above: In this movie, we see galaxies that have formed just 1,700 million years after the Big Bang. Shades of blue trace the gas density, with white being dense, star-forming gas. We zoom in on five galaxies that will soon merge together to form one large galaxy similar in mass to the Milky Way, and briefly zoom back out to view the galaxies’ dark matter, in green. Andrew Pontzen, University College London; Fabio Governato, University of Washington.

Simulation results are being used to interpret observations gathered by NASA missions, such as the Hubble Space Telescope, to further NASA's goal in astrophysics: "Discover how the universe works, explore how it began and evolved, and search for life on planets around other stars."

Project Details

ChaNGA (Charm N-body GrAvity solver), was developed at the University of Washington and the University of Illinois to perform N-body plus hydrodynamics simulations. A unique load-balancing scheme, based on the CHARM runtime system, allows us to obtain good performance on massively parallel systems such as Pleiades supercomputer located at NASA's Ames Research Center.


Image above: The filamentary nature (cosmic web) of dark matter in a volume of the universe, from a simulation produced with the ChaNGA code. In this image, the universe is only 3.5 billion years old. Brighter points indicate denser regions. The volume is 81.5 million light years (25 megaparsecs) per side, and contains 2 billion dark matter particles. Dense knots indicate highly dense regions where galaxies form and cluster together. Andrew Pontzen, University College London.

On Pleiades, we are running high-fidelity simulations of dozens of individual galaxies, spanning from the mass of the Milky Way down to those 1,000 times less massive, with force resolutions under 100 parsec (1 parsec = 3.26 light years). Examples of ongoing projects with these simulations include: quantifying the redistribution of matter in galaxies when supernova energy is deposited; exploring the growth of black holes and the impact of active galactic nuclei (AGN) on galaxy evolution; and determining whether the ultraviolet light from stars in galaxies can "escape" to re-ionize the universe.

Results and Impact

The high-resolution simulations already produced by our collaboration have revolutionized scientists' view of galaxy formation. We have discovered that when supernovae occur in the high-density regions where stars are born, their energy can be transferred to dark matter, pushing the dark matter out of the center of galaxies.


Image above: Image from a high-resolution simulation of a Milky Way-sized galaxy. The simulation was run to the present day (roughly 13.5 billion years of evolution) using NASA's Pleiades supercomputer. The zoomed region where the galaxy formed was selected from the larger volume shown above. This image includes gas, stars, and dark matter, and shows light that traces newly born stars. The spiral arms are regions of stars that extend from the center of the galaxy. Alyson Brooks, Rutgers University.

This process cannot occur in lower-resolution simulations, and thus evaded detection for over a decade, despite other attempts to produce realistic galaxy simulations. These new results explain several long-standing observational challenges to Lambda Cold Dark Matter (CDM) galaxy formation theory, and open new paths of inquiry.

Why HPC Matters

Achieving the high-resolution simulations that have revolutionized our theory of galaxy formation requires billions of particles in a given simulation, and the high-density regions where stars form require small time steps. A single galaxy simulation can take up to 1 million processor hours. Our newly updated version of ChaNGA allows us to scale to hundreds of thousands of cores.

video

Video above: This is a spiral galaxy similar to the Milky Way. We see this galaxy at the present day, 13.75 billion years after the Big Bang. Colors trace density, with yellow-white being the densest part of the galaxy, and blue being the lower density gas and stars. We fly through the disk of galaxy to the approximate location of our Sun, and enjoy the view of the night sky and galaxy. Andrew Pontzen, University College London; Alyson Brooks, Rutgers University.

Tests performed on Pleiades have produced science-ready galaxy simulations, and more state-of-the-art simulations will be run on Pleiades over the next year.

More Information:

SC14 Demo Abstract: http://www.nas.nasa.gov/SC14/demos/demo27.html

Pleiades Supercomputer: http://www.nas.nasa.gov/hecc/resources/pleiades.html

University of Washington Astronomy Department: http://www.astro.washington.edu/

Rutgers Department of Physics and Astronomy: http://www.physics.rutgers.edu/

ChaNGA (Charm N-body GrAvity solver): http://www-hpcc.astro.washington.edu/tools/changa.html

Images (mentioned), Videos (mentioned), Text, Credits: NASA/Maureen Teyssier, Rutgers University/Fabio Governato, The University of Washington.

Best regards, Orbiter.ch

S3 - The first zero gravity flights will begin in 2015











S3 - Swiss Space System logo.

November 25, 2014

Some 400 people have booked their place to make a weightless flight

The aerospace company Swiss Space System (S3) will offer flights in zero gravity in the second half of 2015 in Switzerland. About 400 seats have been reserved since May.

The company will then offer this technology in the United States, Canada, Asia, the Middle East and Europe. And new destinations will still be able to appear in the program of this round the S3 zero gravity world, says Tuesday the company based in Payerne (VD) in a statement.

Parabolic flight. Image Credit: ESA/CNES (Illustration)

These flights "make possible the weightless body and allowing objects to float free of Earth's gravity," she continues. They last less than two hours during which 15 parabolas are performed. Each offers a weightless experience of 20 to 25 seconds.

As early as 2400 Swiss francs

Pricewise, three categories are available to adventurers. In the "party zone", which can accommodate up to 40 passengers, the experience is offered at less than 2000 euros (2400 Swiss francs). In the "premium area", which can accommodate up to 28 passengers, and where fun activities are included, it takes 5,000 euros (6,000 francs).

Parabolic flight. Image Credit: ESA/CNES

For the wealthy, it will be possible to rent the "VIP room" that can hold 12 passengers and wants to offer a "tailored experience." For rent, it will cost 50,000 euros (60,000 francs). In the last two categories, participants will receive a watch brand.

Many requests

"At this stage, we have 400 pre-bookings in Switzerland," said the ats Gregory Loretan, responsible for communication. The demand is such that the company had to increase the number of flights. In Switzerland, "the number of experiments was tripled it," she wrote.

For more information about Swiss Space System (S3), visit: http://www.s-3.ch/

Images (mentioned), Text, Credits: ATS/Translation: Orbiter.ch Aerospace.

Cheers, Orbiter.ch