samedi 7 juillet 2012

Riding the winds, Solar Impulse returns to Europe













SolarImpulse - Destination Morocco patch.

July 7, 2012

It’s been a long but exciting flight with a number of stimulating events that have kept all of us on our toes, but Bertrand Piccard landed the Solar Impulse prototype safely in Madrid-Barajas’s airport at 11:19 PM (UTC), on Friday 6 July.

Rabat to Madrid – Landing in Madrid-Barajas Airport

One of the flight’s singularities was that Bertrand went from beating HB-SIA’s record ground speed, 157km/h, to gaining its fastest reverse speed at 18km/h! I couldn’t help but smile when I thought of one of André’s comments after the first attempted flight to Ouarzazate: “Maybe we should install a couple of rearview mirrors what’s going on in the back!” It wouldn’t have been absolutely necessary this time as Bertrand was offered a splendid view of the sunset over the horizon. In fact, although Bertrand was navigating eastward, the nose of the aircraft was actually pointing westward in direction of the spectacular view. We might even start speculating he did it on purpose to better seize the moment...

To better understand the difficulties Solar Impulse is faced with when there are headwinds and crosswinds, here are a couple of descriptions:

    Groundspeed: can be defined as the speed of the aircraft relatively to the ground.

    True airspeed: the speed of the aircraft in relation to the air mass it’s flying through.

To make it clearer, let’s take the following example: an airplane flies at 50 km/h with no wind. In this case, the groundspeed and true airspeed are equal to the speed of flight. Let’s suppose now that there are headwinds at 20 km/h and the pilot maintains the speed at 50 km/h, in the given air mass. From the cockpit it will seem as though he’s cruising at 50 km/h while his groundspeed will be, in actuality, only 30 km/h.  So in Bertrand’s case, a groundspeed of 157km/h* was aided by an agreeable tailwind while the reverse speed was obviously caused by particularly stubborn headwinds.

Rabat to Madrid – Bertrand Piccard and André Borschberg after landing

It’s been a particularly important flight for the Solar Impulse engineers and technicians as it has once again proven this experimental aircraft’s reliability and energy savings efficiency through never before experienced winds, often faster than the speed of the aircraft.

Madrid is the first and last stop in Europe before HB-SIA and the Solar Impulse team returns home to the lovely landscapes of the Swiss Alps.

*I’ve used km/h in this exercise, but the common speed measure in aviation is knots (kts).

Flight Report: Rabat - Madrid

Pilot: Bertrand Piccard

Take-off time: 06/07/2012 05:17 AM UTC

Time of landing: 06/07/2012 11:19 PM UTC

Flight duration: 17h 3min

Average speed: 60 km/h

Average altitude: 4'879 metres

Distance: 898 km

For more information about SolarImpulse, visit: http://solarimpulse.com/

Images, Text, Credits: Solar Impulse / Jean Revillard.

Greetings, Orbiter.ch

vendredi 6 juillet 2012

Hubble Sees Red Giant Blow a Bubble











NASA - Hubble Space Telescope patch.

July 6, 2012


Camelopardalis, or U Cam for short, is a star nearing the end of its life. As stars run low on fuel, they become unstable. Every few thousand years, U Cam coughs out a nearly spherical shell of gas as a layer of helium around its core begins to fuse. The gas ejected in the star’s latest eruption is clearly visible in this picture as a faint bubble of gas surrounding the star.

U Cam is an example of a carbon star, a rare type of star with an atmosphere that contains more carbon than oxygen. Due to its low surface gravity, typically as much as half of the total mass of a carbon star may be lost by way of powerful stellar winds. Located in the constellation of Camelopardalis (The Giraffe), near the North Celestial Pole, U Cam itself is much smaller than it appears in this Hubble image. In fact, the star would easily fit within a single pixel at the center of the image. Its brightness, however, is enough to saturate the camera's receptors, making the star look much larger than it is.

The shell of gas, which is both much larger and much fainter than its parent star, is visible in intricate detail in Hubble’s portrait. This phenomenon is often quite irregular and unstable, but the shell of gas expelled from U Cam is almost perfectly spherical.

Links:

    ESA Hubble site: http://www.spacetelescope.org/

    NASA Hubble site: http://hubblesite.org/

Image, Text, Credit: ESA / NASA.

Cheers, Orbiter.ch

SolarImpulse - Europe, here we come!













SolarImpulse - Destination Morocco patch.

July 6, 2012

The long awaited moment has finally arrived. This morning at 05:17AM (UTC), Friday 6 July, HB-SIA, piloted by Bertrand Piccard, took-off from its temporary home in Rabat, leaving the Moroccan soil to make its way back to Europe.

HB-SIA, piloted by Bertrand Piccard, ready to flight

The flight had originally been scheduled for this past Tuesday, 3 July, but due to a sudden change in weather conditions, it was postponed. The wait seemed to be long as, in our minds, we had psychologically begun our “goodbyes” to Morocco while our tummies began preparing for jamón and paellas.

But that day has finally come and our mouths are already watering. For those of us that were cheering for Italy in the Euro Cup finals, we just need ensure not to make any uncomfortable slips as we might miss our chance to a nice Spanish meal. In fact, when Bertrand was asked whether he was ready to talk about fútbol, he replied he’s more comfortable speaking about larger balls than those kicked around in stadiums, balls more like balloons that fly in the skies… I think it’s a good strategy and I might adopt a spinoff to secure a Salud! to a soothing glass of red. 

video
SolarImpulse takeoff from Rabat

On more serious terms, today’s flight still remains particularly challenging due to strong crosswinds over the Iberian Peninsula. The initial part of the flight will be smooth, leading HB-SIA towards Tangier and over the Strait of Gibraltar. However, once Bertrand enters Spain, he will need to navigate west of Seville to a first holding point. This is where the winds are expected to be stronger, up to 35-40 knots, which will have a tendency to push the Solar Impulse prototype eastward. The aircraft will therefore need to steer far enough to the West to ensure it is not pushed east of the planned track. Bertrand will then fly towards Toledo and finally to Madrid. A short holding is planned around the Spanish capital, but just long enough to get the green light from the Control Tower for Bertrand to being his final descent.

HB-SIA takeoff from Rabat to Madrid

But at least Bertrand is not alone. This is the first time HB-SIA has a passenger in addition to the pilot. A Moroccan fly has decided to try its luck and taste some of the flavors on the other side of the Strait! Do we have an insect size oxygen mask in the cockpit, anybody?

Expected Landing: Barajas- Madrid Airport (Spain) after 11:00 PM (UTC).

For more information and see online the flight: http://live.solarimpulse.com/

Images, Video, Text, Credits: SolarImpulse / Jean Revillard.

Greetings, Orbiter.ch

Ariane 5 ECA orbits EchoStar XVII and MSG-3



















ESA / Arianespace - Ariane 5 ECA - VA207 poster / MSG-3 Satellite logo.

July 6, 2012

Arianespace launch a success

 Ariane 5 ECA liftoff with EchoStar XVII and MSG-3

On Thursday, July 5, Arianespace successfully launched two satellites: the dedicated Internet satellite EchoStar XVII for the American operator Hughes Network Systems, and the MSG-3 weather satellite for Eumetsat, the European Meteorological Satellite organization.

video
Launch of Ariane 5 with EchoStar 17 and MSG-3

63rd Ariane 5 launch, 49th success in a row

Today's successful Ariane 5 launch once again proves the launcher's operational capabilities. Ariane 5 handles a complete range of missions, from commercial launches into geostationary orbit to launches into special orbits.

Separation of MSG-3 of the second stage of Ariane 5 ECA rocket

This was the 63rd launch of an Ariane 5, and the 49th successful launch in a row.

Arianespace's latest successful mission, the third Ariane 5 launch in 2012, clearly shows that its launch Service & Solutions continue to set the global standard and guarantee independent access to space for all customers, including national and international space agencies, private operators and governments.

302nd and 303rd satellites launched by Arianespace from French Guiana

Arianespace offers the launch services that best match the demanding requirements of leading operators worldwide.

EchoStar XVII spacecraft

EchoStar XVII is the second satellite launched by Arianespace for the American operator Hughes, a subsidiary of EchoStar Corporation. A high-power Ka-band satellite, EchoStar XVII will offer broadband Internet services to companies and individuals in North America. EchoStar XVII is the 37th satellite built by Space Systems/Loral to be launched by Arianespace.

MSG-3 (Meteosat Second Generation) description

MSG-3 (Meteosat Second Generation) is part of a European family of four geostationary meteorological detection and observation satellites. It is the ninth satellite to be launched by Arianespace for Eumetsat. The first two MSG satellites were launched by Arianespace in 2002 and 2005.

 MSG-3 in geostationary orbit

For more information about Arianespace, visit: http://www.arianespace.com/index/index.asp

For more information about  EchoStar, visit: http://www.echostar.com/

For more information about  EUMETSAT, visit: http://www.eumetsat.int/Home/index.htm

Images, Video, Text, Credits: Arianespace / ESA / EUMETSAT / Space Systems / Loral.

Best regards, Orbiter.ch

jeudi 5 juillet 2012

Melas Dorsa reveals a complex geological history on Mars












ESA - Mars Express Mission patch.

5 July 2012

(Click on the images for enlarge)

 Melas Dorsa in full colour

ESA’s Mars Express has imaged an area to the south of the famed Valles Marineris canyon on the Red Planet, showing a wide range of tectonic and impact features.

Melas Dorsa in context

On 17 April, the orbiter pointed its high-resolution stereo camera at the Melas Dorsa region of Mars. This area sits in the volcanic highlands of Mars between Sinai and Thaumasia Plana, 250 km south of Melas Chasma. Melas Chasma itself is part of the Valles Marineris rift system.

The image captures wrinkle ridges, some unusual intersecting faults and an elliptical crater surrounded by ejecta in the shape of a butterfly and with a strange ‘fluid-like’ appearance.

Melas Dorsa impact crater perspective view

Elliptical craters like this 16 km-wide example are formed when asteroids or comets strike the surface of the planet at a shallow angle.

Scientists have suggested that a fluidised ejecta pattern indicates the presence of subsurface ice which melted during the impact. Subsequent impacts have created a number of smaller craters in the ejecta blanket.

Zoom view of flooded crater

The rim of another large crater is visible in the upper centre part of the image, but it appears mostly to have been almost buried during some distant epoch by volcanic dust and ash.

This makes any detailed study of it almost impossible. However, its centre shows
concentric deposits that could provide insights into the composition of the volcanic material that buried it.

Melas Dorsa topography

Several wrinkle ridges can be seen across the image. These form when horizontal compression forces in the crust pushes the crust upwards.

To the left, the ridges are bisected by crustal displacement faults. These have cut into the ridges and the surrounding surface at some later epoch. This highlights the different tectonic phases responsible the formation of this region.

Melas Dorsa 3D anaglyph

Related links:

Mars Express: http://www.esa.int/SPECIALS/Mars_Express/index.html

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

Behind the lens: http://www.esa.int/SPECIALS/Mars_Express/SEMSXE1PGQD_0.html

Frequently asked questions: http://www.esa.int/SPECIALS/Mars_Express/SEM76D9OY2F_0.html

Mars Express blog: http://webservices.esa.int/blog/blog/7

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

For specialists:

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/

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum) / NASA / MGS / MOLA Science Team.

Greetings, Orbiter.ch

mercredi 4 juillet 2012

CERN scientists discover new subatomic particle that could be the Higgs Boson












CERN - European Organization for Nuclear Research logo.

July 4, 2012


Image above: Proton-proton collision in the CMS experiment producing four high-energy muons (red lines). The event shows characteristics expected from the decay of a Higgs boson but it is also consistent with background Standard Model physics processes (Image: CMS).

Scientists at the CERN research centre have discovered a new subatomic particle that could be the elusive Higgs boson, which is believed to be crucial in the formation of the universe.

“I can confirm that a particle has been discovered that is consistent with the Higgs boson theory,” said John Womersley, chief executive of the UK’s Science & Technology Facilities Council, at an event in London.

Joe Incandela, spokesman for one of the two teams hunting for the Higgs particle told an audience at CERN near Geneva: “This is a preliminary result, but we think it’s very strong and very solid.”

Scientists hunting the elusive subatomic “Higgs” particle will unveil findings on Wednesday that take them nearer to understanding how the Big Bang at the dawn of time gave rise to stars, planets and even life.

Physicists who have been smashing particles together at near light-speed at the CERN laboratory near Geneva have already seen tantalising glimpses of the “Higgs boson”, the missing piece of the fundamental theory of physics known as the Standard Model.

The world of science now awaits a mass of evidence big enough to be deemed a formal discovery.

video
 Breakthrough in quest for ‘God Particle’ is “only the beginning”

The secrecy surrounding

Wednesday’s announcement has fuelled speculation that nearly 40 years of research have reached a climax.

CERN accidentally released a video on its website briefly overnight announcing a “new particle” had been observed, but CERN representatives declined to comment on whether that was what would be announced later in the day.

“This video was released due to a technical glitch on our side here at CERN. The final results have not yet been released,” CERN press officer Renilde Vanden Broeck said in Melbourne.

She said the organisation had prepared several videos for a range of outcomes for Wednesday’s announcement. A CERN physicist who knows what will be announced said the discovery was not necessarily definitive.

video
 Best of Higgs Field Theory physicists

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.

Related link:

CERN accidentally released a video: http://blogs.telegraph.co.uk/news/tomchiversscience/100168877/something-like-the-higgs-boson-has-been-found-probably/

Find out more:

    Press release: CERN to give update on Higgs search as curtain raiser to ICHEP conference: http://press.web.cern.ch/press/PressReleases/Releases2012/PR16.12E.html

    ATLAS: http://www.atlas.ch/news/2012/ATLAS-ICHEP-results.html

    CMS: http://cms.web.cern.ch/news/july-4th-seminar-new-cms-higgs-search-results

    About the Higgs Boson: http://press.web.cern.ch/press/background/B01-Higgs_en.html

Image, Videos, Text, Credits: CERN / CMS / Reuters / Euronews.

Best regards, Orbiter.ch

mardi 3 juillet 2012

NASA Astronaut Stephen K. Robinson Leaves Agency










NASA logo.

July 03, 2012

NASA astronaut Stephen Robinson has left the space agency. Robinson ends his 36-year NASA career as a veteran of three spacewalks with more than 48 days of spaceflight experience. Robinson will become a professor at the University of California at Davis in the fall of 2012. His last day at NASA was June 30.

Robinson began work with NASA as a cooperative education student in 1975 at the agency's Ames Research Center at Moffett Field, Calif. He was selected for the astronaut corps in 1995. Robinson served as a mission specialist on four spaceflights, including space shuttle missions STS-85 in 1997, STS-95 in 1998, STS-114 in 2005 and STS-130 in 2010. On his second spaceflight, Robinson was one of Sen. John Glenn's crewmates during Glenn's historic return to space after 36 years.

NASA Astronaut Stephen Robinson

His third flight was NASA's 2005 return to flight mission after the loss of shuttle Columbia in February 2003. During STS-114, Robinson performed the only in-flight spacewalk to repair of a shuttle’s heat-shield. During his final spaceflight, Robinson orchestrated the spacewalks and the complex robotic installation of the Tranquility node and cupola onto the International Space Station.

"Steve will be sorely missed by the Astronaut Office," said Janet Kavandi, director of Flight Crew Operations. "He was a fellow classmate, and I will personally miss his ever-positive attitude and smiling face. We wish him the best in his future endeavors, and we are confident that he will be a positive influence and wonderful mentor to inquisitive minds at the University of California at Davis."

Robinson holds a bachelor of science in mechanical engineering and aeronautical engineering from the University of California at Davis and a master of science and doctorate in mechanical engineering from Stanford University.

For Robinson's complete biography, visit: http://www.jsc.nasa.gov/Bios/htmlbios/robinson.html

Image, Text, Credit: NASA.

Greetings, Orbiter.ch

X-raying the beating heart of a newborn star












ESA - XMM-Newton Mission patch.

3 July 2012


The violent behaviour of a young Sun-like star spinning at high speed and spewing out super-hot plasma has been revealed thanks to the combined X-ray vision of three space telescopes, including ESA’s XMM-Newton.

video
Animation depicting V1647 Ori.

Along with data from NASA’s Chandra and Japan’s Suzaku, the findings shed new light on one of the most fundamental issues in astronomy: the birth of stars like our own Sun.

Such stars form from clouds of gas and dust. These collapse under gravity and develop a dense protostar at their centre, surrounded by an orbiting disc of gas and dust.

The protostar continues to grow as material in the disc works its way towards the centre and falls onto the newborn star at speeds of up to a few hundred kilometres per second.

However, rather than falling onto the protostar, a small fraction of the material is ejected in the form of high-speed jets emanating from the north and south poles of the star.

These jets can be highly variable, pointing to energetic activity in the innermost regions.

But the thick gas and dust envelope surrounding the central star makes it hard to see what is going on.

X-rays can penetrate this dense, obscuring region, and by monitoring variations in the intensity of X-ray emission for the young Sun-like star V1647 Ori, astronomers have been able to deduce what might be happening behind the dusty disc cloaking the star.

The star resides 1300 light-years away in McNeil’s Nebula and was observed with XMM-Newton, Chandra, and Suzaku during two multi-year outbursts. The first lasted from 2003 to 2006; the second has been under way since 2008.

During these extended outbursts the star displays faster growth in mass, a surge in X-ray emission and a dramatic increase in temperature to 50 million degrees celsius.

“We think that magnetic activity on or around the stellar surface creates the super-hot plasma,” says Kenji Hamaguchi, lead author of the paper published in the Astrophysical Journal.

“This behaviour could be sustained by the continual twisting, breaking, and reconnection of magnetic fields, which connect the star and the disc, but which rotate at different speeds.

X-ray lightcurve of V1647 Ori. Credit: Hamaguchi et al.

“Magnetic activity on the stellar surface could also be caused by accretion of material onto it.”

In addition, another variation in X-ray emission was found to repeat regularly, with a period around just one day.

For a star of V1647 Ori’s size, this implies that it is spinning as fast as it can without ripping itself to pieces.

At the same time, matter falls onto the star in large pancake-shaped hotspots on opposite sides of the stellar surface.

“We think the super-hot plasma is located on the surface of the star, which rotates with a one day period,” says Dr Hamaguchi.

“The rising and falling in flux that we see would probably be due to the emergence and disappearance of the bright hot spot in our line of sight.”

Yet the regular heartbeat of X-ray emission seen at various times between 2004 to the present day suggest that despite the chaotic behavior, the large-scale configuration of the star–disc system remains stable over timescales of several years.

“These observations of V1647 Ori by this trio of X-ray satellites provide new insight into what might be happening inside the dusty discs of newly-forming stars,” said Norbert Schartel, ESA’s Project Scientist for XMM-Newton.

Notes for Editors:

“X-raying the Beating Heart of a Newborn Star: Rotational Modulation of High-energy Radiation from V1647 Ori” by K. Hamaguchi et al. is published in the Astrophysical Journal, vol. 754, 20 July 2012.

Animation caption:

Artist impression of what might be happening behind the thick dust disc surrounding the young Sun-like star V1647 Ori. X-ray observations by ESA’s XMM-Newton, NASA’s Chandra and Japan’s Suzaku space observatories have probed the interior of the dust disc to find a rapidly-rotating star spinning with a period of one day. At 80% the mass of our Sun and with a diameter approximately four times larger, spinning at this rate nears break-up speed for a star of this size. The data also suggest that matter is accreting onto the stellar surface in two pancake-shaped hotspots located on opposite sides of the star, in which the matter heats up and the high temperature plasma is confined. Credits: C. Carreau.

More about XMM-Newton:

XMM-Newton overview: http://www.esa.int/esaSC/120385_index_0_m.html

XMM-Newton factsheet: http://www.esa.int/esaSC/SEM14YS1VED_index_0.html

XMM-Newton operations: http://www.esa.int/SPECIALS/Operations/SEMI2HZTIVE_0.html

Graphic (mentioned), Video, Text, Credits: ESA / C. Carreau.

Greetings, Orbiter.ch

A geyser of hot gas flowing from a star












ESA - Hubble Space Telescope logo.

3 July 2012

 Hubble image of Herbig-Haro object HH 110

The NASA/ESA Hubble Space Telescope has captured a new image of Herbig-Haro 110, a geyser of hot gas flowing from a newborn star.

Although Herbig–Haro (HH) objects come in a wide array of shapes, the basic configuration is usually the same. Twin jets of heated gas, ejected in opposite directions from a forming star, stream through interstellar space. These outflows are fueled by gas falling onto the young star, which is surrounded by a disc of dust and gas. If the disc is the fuel tank, the star is the gravitational engine, and the jets are the exhaust.

In Hubble’s image of HH 110, one such turbulent streamer of gas can clearly be seen streaking across the frame.

The intricate structures within HH 110 and other Herbig–Haro objects exist because the jets are not being blown through a pure vacuum. When the energetic and fast-moving Herbig–Haro jets slam into colder gas, they form shock fronts that look and behave much like the bow waves that form in front of a boat. These so-called bow shocks, which glow thanks to very high temperatures, are a distinctive feature of Herbig-Haro objects.

The structure of HH 110 and other objects like it acts like a ticker-tape, recording the activity of the star that is the origin of the jet. Erratic outbursts from the star happen at times when more matter is falling in, and these are recorded as brighter knots or blobs within the Herbig-Haro object, which move along the jet over the years. Although the jets are very fast-moving, they are also very large: the streamer of gas in this image is around half a light-year in length. This means that the motion appears quite slow from our vantage point, even when measured over years (see heic1113).

The NASA / ESA Hubble Space Telescope during Servicing Mission 4

By measuring the current speed and positions of blobs within a Herbig-Haro object, astronomers can rewind time, projecting the motion of the knots backwards to the moment when they were emitted. This in turn tells the scientists about the environment directly around the forming star.

Notes:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

Links:

    Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

    NASA press release: http://hubblesite.org/news/2012/30

Images, Text, Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA).

Cheers, Orbiter.ch

SMOS satellite measurements improve as ground radars switch off









ESA - SMOS Mission logo.

3 July 2012

Over a dozen radio signals that have hindered data collection on ESA’s SMOS water mission have been switched off. The effort also benefits satellites such as NASA’s Aquarius mission, which measures ocean salinity at the same frequency.

We all know what happens when you place a cell phone too close to a speaker: seconds before the phone rings, that obnoxious buzz interrupts your favourite song.

Sea surface salinity

This is radio interference – an unwanted reception of radio signals. Not only can it interrupt the music from your stereo, it can also impede satellite measurements.

ESA’s Soil Moisture and Ocean Salinity (SMOS) satellite was launched in 2009 to improve our understanding of our planet’s water cycle. In order to do this, it measures the microwaves emitted by Earth in the 1400–1427 MHz range. 

SMOS immediately revealed that many unlawful signals were being transmitted around the world in this frequency range, rendering some of its measurements unusable for scientific purposes.

Radio interference

Over the years, ESA has investigated exactly where the interference is coming from.

As national authorities have collaborated with ESA to pinpoint the origin and switch these unlawful emissions off, the interference has waned.

One of the largest areas of contamination in the northern hemisphere is over the North Pacific and Atlantic oceans, primarily from military radars.

Over recent years, authorities from Canada and Greenland have been asked to take action. Canada started to refurbish their equipment in late 2011, while Greenland switched off their transmitters in March 2011.

SMOS in orbit

At least 13 sources of interference have now been switched off in the northern latitudes. This has significantly improved SMOS observations at these high latitudes, which were previously so contaminated that accurate salinity measurements were not possible above 45 degrees latitude as the satellite headed north.

However, the few remaining sources can contaminate areas 3000 km away, especially as SMOS climbs north towards North America.

The efforts to reduce interference will benefit other missions carrying similar detectors, such as NASA’s Aquarius satellite, which was launched last year.

Aquarius also observes ocean salinity and, in addition, it measures sea-surface roughness to help understand how roughness affects salinity measurements.

Cleaner SMOS results

A unique feature of SMOS is that it also measures soil moisture. SMOS and Aquarius readings are highly complementary: SMOS repeats coverage faster and at finer detail, while Aquarius has better ‘pixel by pixel’ accuracy.

Scientists are trying to combine both sets of measurements in the best way to improve global salinity maps.

“Combining SMOS and Aquarius new observations will allow us to map ocean surface salinity with an unprecedented spatial and temporal resolution,” said Nicolas Reul from the French Research Institute for Exploration of the Sea.

“In particular, salinity fronts and the movement of water across tropical oceans and within strong currents – such as the Gulf Stream – shall be better detected and tracked than with single-sensor observations.”

Related links:

SMOS: http://www.esa.int/SPECIALS/smos/index.html

Access SMOS data: http://earth.esa.int/SMOS/

SMOS ocean user meeting at EGU 2012: https://earth.esa.int/web/guest/smos-egu-2012

Ifremer–Cersat Salinity Center: http://www.salinityremotesensing.ifremer.fr/home

Images, Animations, Text, Credits: ESA / AOES Medialab / N. Reul, IFREMER / CATDS.

Best regards, Orbiter.ch

Mission accomplished for Galileo's pathfinder GIOVE-A












ESA - Galileo - GIOVE Mission patch.

3 July 2012

With the initial satellites of the Galileo constellation working well in orbit, it has been decided to end the mission of ESA’s pioneering GIOVE-A navigation satellite.

Launched on 28 December 2005, this first experimental satellite performed the vital task of securing the radio frequencies provisionally set aside for Galileo by the International Telecommunications Union.

It also flight-tested Galileo atomic clocks and other equipment in space for the very first time and investigated the radiation environment of medium-altitude orbits, never used before by a European mission. 

Artist's impression of GIOVE-A

ESA formally ended GIOVE-A’s mission at the end of June, although it will go on being operated for now by prime contractor Surrey Satellite Technology Ltd of Guildford, UK, to gather radiation data and performance results from a GPS receiver.

“GIOVE-A had a design life of only 27 months, so to continue operating for 78 months is impressive,” said Valter Alpe, managing GIOVE activities for ESA.

“In August 2009, the satellite was moved into a graveyard orbit around 100 km above its normal 23 222 km to make way for the Galileo validation satellites.

“The first two of these were launched on 21 October 2011 and are performing well, so while GIOVE-A has served ESA well it no longer has a job to do.”

Lift off of Soyuz carrying GIOVE-A

Built to a tight deadline by SSTL, GIOVE-A carries a rubidium atomic clock accurate to three seconds in a million years.

On 27 April 2008 it was joined by GIOVE-B, built by an Astrium-led consortium, which carries an even more accurate passive hydrogen maser clock – the first to be flown in space for navigation, accurate to one second in three million years – as well as a second rubidium clock. Operational Galileo satellites carry two pairs of both kinds of clock, for redundancy.

They are very different missions in other ways too. The GIOVEs were modified from existing satellite platforms: a prototype geostationary minisatellite for GIOVE-A, and a commercial French Proteus platform typically used for Earth observation for GIOVE-B.

GIOVE-A mated with Fregat launcher upper stage

Galileo satellites are based on an entirely new platform and improved payload, specifically engineered for extremely high reliability, only intended to go into safe mode for a few days over their planned 12 years of operation thanks to a robust design based on reconfigurable redundancy.

Even when entering ‘intermediate safe mode’ they can continue to supply navigation signals, although without the usual service guarantee.

GIOVE-B, with an orbital lifetime of 50 months and counting, will be used in payload fine calibration tests this summer with the two Galileo satellites.

Then, in September, it will be manoeuvred into a graveyard orbit 300 km higher. At this point, GIOVE-B’s own mission will end.

GIOVE-B in orbit

“Early October will see the launch of the next two Galileo satellites by Soyuz rocket from Europe’s Spaceport in French Guiana,” added Valter.

“This will be an important step forward because four satellites are the minimum to perform navigation measurements, so Galileo system testing can proceed.” A follow-up batch of full operational capability Galileo satellites is being built by Germany’s OHB and SSTL, with initial Galileo services forecast to be available by 2014.

External links:

European Commission - Galileo: http://ec.europa.eu/enterprise/policies/satnav/galileo/index_en.htm

Surrey Satellite Technolgy Limited: http://www.sstl.co.uk/

OHB: https://www.ohb-system.de/

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

Greetings, Orbiter.ch

NASA Extends Sympathy to Poindexter Family on Death of Former Astronaut










NASA logo.

July 03, 2012

Former NASA astronaut and space shuttle commander Alan "Dex" Poindexter died while on vacation with his family July 1 in Pensacola, Fla. A veteran of two spaceflights, Poindexter spent a total of 28 days in space.

Poindexter, a U.S. Navy captain, commanded the STS-131 space shuttle Discovery mission to the International Space Station in 2010, delivering more than 13,000 pounds of hardware and equipment. He was the pilot for shuttle Atlantis' STS-122 mission that delivered and installed the European Space Agency's Columbus laboratory on the station in 2008.

"Alan and I joined the astronaut corps in 1998 and flew together on STS-122, which was truly an incredible experience," said NASA Associate Administrator for Education and former astronaut Leland Melvin. "He was a passionate, caring and selfless individual who will be missed by all."

Astronaut Alan "Dex" Poindexter

"We in the astronaut family have lost not only a dear friend, but also a patriot of the United States," said Peggy Whitson, chief of the Astronaut Office at NASA's Johnson Space Center in Houston. "He proudly served his country for 26 years as a fighter pilot, test pilot, astronaut and commander of a space shuttle. I am proud to have both flown in space and worked with him for so many years. Dex will be deeply missed by those of us at Johnson and the entire NASA family."

Poindexter earned an undergraduate degree with highest honors from the Georgia Institute of Technology in Atlanta and a graduate degree from the Naval Postgraduate School in Monterey, Calif. He was selected as an astronaut candidate in June 1998 and served in the Astronaut Office, Shuttle Operations Branch at Johnson as the lead support astronaut for NASA's Kennedy Space Center in Florida. He also served as a spacecraft communicator, or CAPCOM, for multiple missions.

"Dex was a wonderful human being and a pleasure to have in the astronaut office," Janet Kavandi, fellow astronaut and Director of Flight Crew Operations said. "His good-natured demeanor made him approachable to his crews and the many people at Johnson and Kennedy who enabled his missions."

Poindexter retired from NASA and the astronaut corps in 2010 and returned to serve in the United States Navy as Dean of Students at the Naval Postgraduate School.

For Poindexter's complete biography, please visit: http://www.jsc.nasa.gov/Bios/htmlbios/poindexter.html 

Image, Text, Credit: NASA.

My condolences to the family and his NASA colleagues, Orbiter.ch

lundi 2 juillet 2012

Sounding Rocket Mission to Observe Magnetic Fields on the Sun






HINODE logo.

July 2, 2012


Image above: SUMI’s instruments are designed to study magnetic fields of the sun’s chromosphere -- a thin layer of solar atmosphere sandwiched between the visible surface, photosphere and its atmosphere, the corona. Hinode, a collaborative mission of the space agencies of Japan, the United States, United Kingdom and Europe, captured these very dynamic pictures of our sun's chromosphere on Jan. 12, 2007. Image credit: JAXA / NASA.

On July 5, NASA will launch a mission called the Solar Ultraviolet Magnetograph Investigation or SUMI, to study the intricate, constantly changing magnetic fields on the sun in a hard-to-observe area of the sun's low atmosphere called the chromosphere.

Magnetic fields, and the intense magnetic energy they help marshal, lie at the heart of how the sun can create huge explosions of light such as solar flares and eruptions of particles such as coronal mass ejections (CMEs). While there are already instruments – both on the ground and flying in space – that can measure these fields, each is constrained to observe the fields on a particular layer of the sun's surface or atmosphere. Moreover, none of them can see the layer SUMI will observe.

"What's novel with this instrument is that it observes ultraviolet light, when all the others look at infrared or visible light," says Jonathan Cirtain, a solar scientist at NASA's Marshall Space Flight Center in Huntsville, Ala. and the principal investigator for SUMI. "Those wavelengths of light correspond to the lowest levels in the sun's atmosphere, but SUMI will look at locations higher in the chromosphere."


Image above: The chromosphere is a narrow layer above the photosphere that raises in temperature with height. Normally, it can't be seen by the naked eye because the light from the photosphere of the Sun overpowers it. The coloring of the chromosphere (deep red) is caused by the immense hydrogen supply it contains. Credit: NASA.

This higher layer of the chromosphere is known as the transition region – because the chromosphere transitions here into the part of the sun's atmosphere called the corona -- and it is a region that is dominated by the magnetic fields and in which solar material heats up dramatically forming the corona and the base of the solar wind. Understanding the structure of the magnetic fields in this region will then allow us to understand how the corona is heated and how the solar wind is formed. It is also an area believed to be where flare accelerated particles originate, so understanding the processes at play in the transition region can help with models to predict such eruptions on the sun.

To measure magnetic fields in the chromosphere, SUMI will observe the ultraviolet (UV) light emitted from two types of atoms on the sun, Magnesium 2 and Carbon 4. Through established methods of measuring how the light is affected as it travels through the magnetic environment of the solar atmosphere towards Earth, scientists can measure the original strength and direction of the magnetic fields, thus creating a three-dimensional magnetic map of the region.

HINODE spacecraft. Image credit: JAXA / NASA.

This trip for SUMI is largely a test flight to make sure the instrument works and to assess possible improvements. The instrument flew once before in July 2010 but experienced a much higher G-force than expected, which broke screws holding the main mirror in place so it could not gather accurate data. The team has now reinforced the mirror.

"With the knowledge we get from a successful SUMI mission, we can go on to build space-based instrumentation that will help us understand the processes that form flares and CME's and help us predict space weather," says Cirtain.

SUMI will launch from White Sands Missile Range in New Mexico on a Black Brant rocket. The flight will last about eight minutes total.

Images (mentioned), Text, Credit: NASA Goddard Space Flight Center / Karen C. Fox.

Greetings, Orbiter.ch

Hubble Sees a Vapor of Stars












NASA - Hubble Space Telescope patch.

July 2, 2012


Relatively few galaxies possess the sweeping, luminous spiral arms or brightly glowing center of our home galaxy the Milky Way. In fact, most galaxies look like small, amorphous clouds of vapor. One of these galaxies is DDO 82, captured by the Hubble Space Telescope. Though tiny compared to the Milky Way, such dwarf galaxies may contain between a few million and a few billion stars.

DDO 82, also known by the designation UGC 5692, is not without a hint of structure, however. Astronomers classify it as an "Sm galaxy," or Magellanic spiral galaxy, named after the Large Magellanic Cloud, a dwarf galaxy that orbits the Milky Way. That galaxy, like DDO 82, is said to have one spiral arm.

DDO 82 can be found in the constellation of Ursa Major (the Great Bear) approximately 13 million light-years away. The object is considered part of the M81 Group of around three dozen galaxies. DDO 82 gets its name from its entry number in the David Dunlap Observatory Catalogue. Canadian astronomer Sidney van den Bergh originally compiled this list of dwarf galaxies in 1959.

The image is made up of exposures taken in visible and infrared light by Hubble’s Advanced Camera for Surveys.

For more information about Hubble visit:

http://www.nasa.gov/hubble and http://hubblesite.org/

ESA Hubble site: http://www.spacetelescope.org/

Image, Text, Credit: ESA / NASA.

Cheers, Orbiter.ch

Global Change Observation Mission 1st - Water "SHIZUKU" (GCOM-W1) Inserted into A-Train Orbit












JAXA - GCOM-W1 "SHIZUKU" Mission patch.

July 2, 2012 (JST)

The Japan Aerospace Exploration Agency (JAXA) confirmed that the Global Change Observation Mission 1st - Water "SHIZUKU" (GCOM-W1) was inserted into a planned position on the A-Train orbit as a result of orbit control performed on June 29, 2012. The SHIZUKU was launched from the Tanegashima Space Center at 1:39 p.m. on May 18, 2012.

The SHIZUKU is flying in front of the Aqua satellite, thus it takes the most front position in the A-Train until another National Aeronautics and Space Administration (NASA) satellite, OCO-2 (USA) joins the constellation.

Global Change Observation Mission 1st - Water "SHIZUKU" (GCOM-W1)

We have received a welcome message from Dr. Michael Freilich, Earth Science Division Director, of the NASA, as follows: "We are pleased to welcome JAXA and SHIZUKU as a member of the international A-Train constellation. The merging and sharing of data from multiple A-Train satellites has already led to significant advances in atmospheric science, and the addition of the Advanced Microwave Scanning Radiometer 2 (AMSR2) dataset will be an important extension of the A-Train's scientific capabilities."

JAXA will increase the rotation speed of the AMSR2 aboard the SHIZUKU from the lower rotation mode (11 rpm) to the regular observation mode of 40 rpm to verify its observation performance.

Image Credit: NASA.

Outline of A-Train (The Afternoon Constellation)

The Afternoon Constellation, or the "A-Train", is an Earth observation satellite constellation run by NASA, and consists of multiple satellites orbiting the Earth in close proximity at an altitude of about 700km, crossing the equator at around 1:30 p.m. local mean solar time. This system allows satellites from various countries to cooperate in earth observations. Currently, with the A-train, the following satellites are participating: Aqua (NASA, U.S.A.), CloudSat (NASA, U.S.A), CALIPSO (NASA, U.S.A./ CNES, France), Aura (NASA, U.S.A.) and Japan has participated in the system for the first time with the SHIZUKU.

Special Features of the A-Train

For Earth observation, it is very efficient to perform observations by measuring the same one location with various sensors at the same time. With various satellites lining up on the almost same orbit, the A-Train enables us to observe the same location on the Earth by multiple satellites around the same time (approximately within 10 minutes.) The position of each satellite is strictly controlled; therefore, a new comer has to be injected into a pre-determined location that does not interfere with other already-flying members. The SHIZUKU entered the A-Train orbit successfully by utilizing JAXA's rendezvous technology. It is the first experience for JAXA to operate a satellite in the constellation flying on the almost same orbit.

(Reference) A-Train (Satellite constellation) member satellites:

- Aura (NASA, USA) launched on July 15, 2004
To acquire observation data for elucidating the composition of the earth atmosphere, its chemical react, and dynamics.

- CALIPSO (NASA/CNES, USA/France) launched on April 28 2006
An optical lidar satellite to acquire observation data to clarify impact of aerosol and clouds on the Earth's climate

- CloudSat (NASA, USA launched on April 28, 2006)
A radio wave radar satellite to acquire observation data to study the impact of clouds on the Earth's climate

- Aqua (NASA, USA launched on May 4, 2002)
The name came from the Latin word "Aqua" meaning water. The satellite acquires observation data on the Earth's various water circulations including water vapor in the atmosphere and from the ocean, clouds, precipitation, ocean ice, and ground water.

Mission website:

SHIZUKU Special Site: http://www.jaxa.jp/countdown/f21/index_e.html

Images, Text, Credits: Japan Aerospace Exploration Agency (JAXA) / NASA.

Greetings, Orbiter.ch