vendredi 26 avril 2013

China launches high-definition earth observation satellite














CASC - China Aerospace Science and Technology Corporation logo / EXA - NEE 01 Pegaso patch.

April 26, 2013

It is also the 19th launch of a Long March-2D, and the 175th of the Long March rocket series.

Long March-2D launch

China successfully sent high-definition earth observation satellite "Gaofen-1" into space at 12:13 p.m. Beijing time on Friday, announced the State Administration of Science, Technology and Industry for National Defence (SASTIND).

video
Launch of Gaofen-1 & other secondary payloads on Long March-2D

The mission was carried by a Long March-2D carrier rocket from northwest China's Jiuquan Satellite Launch Center. The rocket also carried three small satellites made by Ecuador, Argentina and Turkey as well as two satellite splitters from the Netherlands.

Launched together with Gaofen-1 were three small CubeSats: NEE-01 Pegaso, Turksat-3USAT and CubeBug-1 ‘Capitán Beto’. NEE 01 Pegaso is a 1U CubeSat and is the first satellite to be launched for Ecuador.

NEE-01 Pegaso, first Ecuador satellite

It is also the 19th launch of a Long March-2D, and the 175th of the Long March rocket series.

Developed by the China Academy of Space Technology, Gaofen-1 is the first of five or six satellites to be launched for the high-definition earth observation system (HDEOS) between 2011 and 2016.

The system could play an important role in disaster prevention and relief, climate change monitoring, geographical mapping, environment and resource surveying as well as precision agriculture.

The major users of the satellite will be the Ministry of Land and Resources, Ministry of Environmental Protection and Ministry of Agriculture, said the SASTIND, adding that the launch is of great significance in improving China's satellite development level and increasing its degree of self-sufficiency in high-definition remote sensing data.

Gaofen-1 satellite

There are over 50 countries to date that own or operate earth observation satellites, and the data they collect is widely used for economic and social activities and in other science research fields.

High-definition earth observation technology is an important method to obtain information rapidly, a field that all major space powers are developing.

China set up the special project for the HDEOS development in 2006. It received government approval and was initiated in 2010.

According to the project, the country will establish an earth observation system capable of great precision in time, space and spectral aspects, and integrate it with other measures to build an observation system with all-weather, round-the-clock and global coverage.

For more information about China Aerospace Science and Technology Corporation (CASC), visit: http://english.spacechina.com/n16421/index.html

Images, Video, Text, Credits: CASC / ANI / EXA / Chinanews.com / Orbiter.ch Aerospace.

Greetings, Orbiter.ch

Docking of Progress at the ISS will occur despite a broken antenna










ROSCOSMOS - Russian Vehicles patch.

April 26, 2013

 Progress docking at ISS

On Friday, April 26, the Russian spacecraft "Progress" has successfully docked with the ISS, despite a broken antenna systems "course." BBC News website conducted a live online broadcast.

video
Docking of Progress at the ISS will occur despite a broken antenna (in Russian)

The space "Truck" delivered to the ISS more than 2.5 tonnes of cargo, including food, water, air tanks and oxygen, sanitary facilities, fuel and equipment for the station modules. In addition, the crew received a parcel from home and psychologists.

Russian Orbital Segment description

Among other things, "Progress M-19M" brought Pavel Vinogradov, Alexander Misurkin, Roman Romanenko, Christopher Cassidy, Thomas Mashburn and Chris Hadfield fresh fruit and vegetables, as well as their favorite foods and drinks.

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

For more information about ROSCOSMOS, visit: http://www.federalspace.ru/main.php?lang=ru

Images, Video, Text, Credits: Roscosmos TV / ROSCOSMOS / Translation: Orbiter.ch Aerospace.

Cheers, Orbiter.ch

The launch of a spacecraft Glonass-M












ROSCOSMOS - Glonass Mission patch.

26.04.2013

 Soyuz-2.1b with the upper stage Fregat and navigation spacecraft Glonass-M launch

April 26 at 9:00 MSK 23 minutes from Launch Complex 43 area state test launch site of the Ministry of Defense of the Russian Federation (cosmodrome Plesetsk) is made of a space rocket launch of "Soyuz-2.1b" with the upper stage (RB) "Fregat" and spacecraft ( KA) "Glonass-M". Start calculation made a joint Russian Defense Ministry experts and enterprises of the rocket-space industry.

According to the flight cyclogram Glonass-M (manufactured by JSC "ISS them. Academician Reshetnev" Zheleznogorsk) launched into the target orbit and adopted by the management. He will join the existing constellation of Russian global navigation satellite system GLONASS.

Work on preparing the spacecraft "Glonass-M"

Rocket "Soyuz-2.1b" is created in the Federal State Unitary Enterprise "SRP" TsSKB-Progress "(Samara), upper stage" Fregat "made in FSUE" NPO. Lavochkin. "

Nominal orbital group of the GLONASS system consists of 24 satellites placed in three orbital planes are separated by the longitude of the ascending node at 120 °. In each orbital plane should be placed evenly 8 spacecraft, which will provide a steady signal. Orbit navigation satellites have the following characteristics: height above the surface of the Earth - 19,100 km, inclination - 64,8 °, orbital period around the Earth - 11 hours 15 minutes.

GLONASS-M spacecraft

This configuration allows you to provide continuous and global coverage of the Earth's surface and near-earth space.

The scheme GLONASS constellation

The GLONASS system is defined as a dual-use system that provides the solution of problems in the interests of the Russian Defense Ministry and civilian users. Access to civilian navigation signals of global navigation satellite system GLONASS available to Russian and foreign customers at no cost and without restrictions.

The GLONASS system: http://www.federalspace.ru/main.php?id=24#gl

Original text in Russian: http://www.federalspace.ru/main.php?id=2&nid=20062

Images, Tex, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / ROSCOSMOS / Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

jeudi 25 avril 2013

Entire galaxies feel the heat from newborn stars












ESA - Hubble Space Telescope logo.

25 April 2013

Bursts of star birth can curtail future galaxy growth

Artist's impression of a galaxy undergoing a starburst

Astronomers using the NASA/ESA Hubble Space Telescope have shown for the first time that bursts of star formation have a major impact far beyond the boundaries of their host galaxy. These energetic events can affect galactic gas at distances of up to twenty times greater than the visible size of the galaxy — altering how the galaxy evolves, and how matter and energy is spread throughout the Universe.

When galaxies form new stars, they sometimes do so in frantic episodes of activity known as starbursts. These events were commonplace in the early Universe, but are rarer in nearby galaxies.

During these bursts, hundreds of millions of stars are born, and their combined effect can drive a powerful wind that travels out of the galaxy. These winds were known to affect their host galaxy — but this new research now shows that they have a significantly greater effect than previously thought.

video
Probing a galactic halo with Hubble

An international team of astronomers observed 20 nearby galaxies, some of which were known to be undergoing a starburst. They found that the winds accompanying these star formation processes were capable of ionising [1] gas up to 650 000 light-years from the galactic centre — around twenty times further out than the visible size of the galaxy. This is the first direct observational evidence of local starbursts impacting the bulk of the gas around their host galaxy, and has important consequences for how that galaxy continues to evolve and form stars.

“The extended material around galaxies is hard to study, as it’s so faint,” says team member Vivienne Wild of the University of St. Andrews. “But it’s important — these envelopes of cool gas hold vital clues about how galaxies grow, process mass and energy, and finally die. We’re exploring a new frontier in galaxy evolution!”

The team used the Cosmic Origins Spectrograph (COS) instrument [2] on the NASA/ESA Hubble Space Telescope to analyse light from a mixed sample of starburst and control galaxies. They were able to probe these faint envelopes by exploiting even more distant objects — quasars, the intensely luminous centres of distant galaxies powered by huge black holes. By analysing the light from these quasars after it passed through the foreground galaxies, the team could probe the galaxies themselves.

video
Animation of a starburst galaxy (artist’s impression)

“Hubble is the only observatory that can carry out the observations necessary for a study like this,” says lead author Sanchayeeta Borthakur, of Johns Hopkins University. “We needed a space-based telescope to probe the hot gas, and the only instrument capable of measuring the extended envelopes of galaxies is COS.”

The starburst galaxies within the sample were seen to have large amounts of highly ionised gas in their halos — but the galaxies that were not undergoing a starburst did not. The team found that this ionisation was caused by the energetic winds created alongside newly forming stars.

This has consequences for the future of the galaxies hosting the starbursts. Galaxies grow by accreting gas from the space surrounding them, and converting this gas into stars. As these winds ionise the future fuel reservoir of gas in the galaxy’s envelope, the availability of cool gas falls — regulating any future star formation.

“Starbursts are important phenomena — they not only dictate the future evolution of a single galaxy, but also influence the cycle of matter and energy in the Universe as a whole,” says team member Timothy Heckman, of Johns Hopkins University. “The envelopes of galaxies are the interface between galaxies and the rest of the Universe — and we’re just beginning to fully explore the processes at work within them.”

The team's results will appear in the 1 May 2013 issue of The Astrophysical Journal.

Notes:

[1] A gas is said to be ionised when its atoms have lost one or more electrons — in this case by energetic winds exciting galactic gas and knocking electrons out of the atoms within.

[2] Spectrographs are instruments that break light into its constituent colours and measure the intensity of each colour, revealing information about the object emitting the light — such as its chemical composition, temperature, density, or velocity.

More information:

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

The research is presented in a paper entitled “The Impact of Starbursts on the Circumgalactic Medium”, published in the 1 May 2013 issue of The Astrophysical Journal.

The international team of astronomers in this study consists of: S. Borthakur (Johns Hopkins University, USA), T. Heckman (Johns Hopkins University, USA), D. Strickland (Johns Hopkins University, USA), V. Wild (University of St. Andrews, UK), D. Schiminovich (Columbia University, USA).

Links:

Research paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1308.pdf

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

Hubble's Instruments: COS — Cosmic Origins Spectrograph: http://www.spacetelescope.org/about/general/instruments/cos/

Images, Text, Credits: ESA, NASA, L. Calçada.

Greetings, Orbiter.ch

Einstein Was Right — So Far












ESO - European Southern Observatory logo.

25 April 2013

Record-breaking pulsar takes tests of general relativity into new territory

Artist’s impression of the pulsar PSR J0348+0432 and its white dwarf companion

Astronomers have used ESO’s Very Large Telescope, along with radio telescopes around the world, to find and study a bizarre stellar pair consisting of the most massive neutron star confirmed so far, orbited by a white dwarf star. This strange new binary allows tests of Einstein’s theory of gravity — general relativity — in ways that were not possible up to now. So far the new observations exactly agree with the predictions from general relativity and are inconsistent with some alternative theories. The results will appear in the journal Science on 26 April 2013.

An international team has discovered an exotic double object that consists of a tiny, but unusually heavy neutron star that spins 25 times each second, orbited every two and a half hours by a white dwarf star. The neutron star is a pulsar that is giving off radio waves that can be picked up on Earth by radio telescopes. Although this unusual pair is very interesting in its own right it is also a unique laboratory for testing the limits of physical theories.

Artist’s impression of the pulsar PSR J0348+0432 and its white dwarf companion

This pulsar is named PSR J0348+0432 and is the remains of a supernova explosion. It is twice as heavy as the Sun, but just 20 kilometres across. The gravity at its surface is more than 300 billion times stronger than that on Earth and at its centre every sugar-cubed-sized volume has more than one billion tonnes of matter squeezed into it. Its companion white dwarf star is only slightly less exotic; it is the glowing remains of a much lighter star that has lost its atmosphere and is slowly cooling.

“I was observing the system with ESO’s Very Large Telescope, looking for changes in the light emitted from the white dwarf caused by its motion around the pulsar,” says John Antoniadis, a PhD student at the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn and lead author of the paper. “A quick on-the-spot analysis made me realise that the pulsar was quite a heavyweight. It is twice the mass of the Sun, making it the most massive neutron star that we know of and also an excellent laboratory for fundamental physics.”

Artist’s impression of the pulsar PSR J0348+0432 and its white dwarf companion

Einstein’s general theory of relativity, which explains gravity as a consequence of the curvature of spacetime created by the presence of mass and energy, has withstood all tests since it was first published almost a century ago. But it cannot be the final explanation and must ultimately break down [1].

Physicists have devised other theories of gravity that make different predictions from general relativity. For some of these alternatives, these differences would only show up in extremely strong gravitational fields that cannot be found in the Solar System. In terms of gravity, PSR J0348+0432 is a truly extreme object, even compared to the other pulsars that have been used in high precision tests of Einstein’s general relativity [2]. In such strong gravitational fields small increases in the mass can lead to large changes in the spacetime around such objects. Up to now astronomers had no idea what would happen in the presence of such a massive neutron star as PSR J0348+0432. It offers the unique opportunity to push tests into new territory.

video

Video above: Artist’s impression of the pulsar PSR J0348+0432 and its white dwarf companion.

The team combined Very Large Telescope observations of the white dwarf with very precise timing of the pulsar from radio telescopes [3]. Such a close binary radiates gravitational waves and loses energy. This causes the orbital period to change very slightly and the predictions for this change from general relativity and other competing theories are different.

“Our radio observations were so precise that we have already been able to measure a change in the orbital period of 8 millionths of a second per year, exactly what Einstein’s theory predicts,” states Paulo Freire, another team member.

This is just the start of detailed studies of this unique object and astronomers will be using it to test general relativity to ever greater precision as time goes on.

Notes:

[1] General relativity is not consistent with the other great theory of twentieth century physics, quantum mechanics. It also predicts singularities under some circumstances, where some quantities tend to infinity, such as the centre of a black hole.

[2] The first binary pulsar, PSR B1913+16, was discovered by Joseph Hooton Taylor, Jr. and Russell Hulse, for which they won the 1993 Nobel Prize in Physics. They accurately measured the changes in the properties of this remarkable object and showed that they were precisely consistent with the gravitational radiation energy losses predicted by general relativity.

[3] This work made use of data from the Effelsberg, Arecibo and Green Bank radio telescopes as well as the ESO Very Large Telescope and the William Herschel Telescope optical telescopes.

More information:

This research was presented in a paper “A Massive Pulsar in a Compact Relativistic Orbit”, by John Antoniadis et al., to appear in the journal Science on 26 April 2013.

The team is composed of John Antoniadis (Max-Planck-Institut für Radioastronomie [MPIfR], Bonn, Germany), Paulo C. C. Freire (MPIfR), Norbert Wex (MPIfR), Thomas M. Tauris (Argelander Institut für Astronomie, Bonn, Germany; MPIfR), Ryan S. Lynch (McGill University, Montreal, Canada), Marten H. van Kerkwijk (University of Toronto, Canada), Michael Kramer (MPIfR; Jodrell Bank Centre for Astrophysics, The University of Manchester, United Kingdom), Cees Bassa (Jodrell Bank), Vik S. Dhillon (University of Sheffield, United Kingdom), Thomas Driebe (Deutsches Zentrum für Luft- und Raumfahrt, Bonn, Germany), Jason W. T. Hessels (ASTRON, the Netherlands Institute for Radio Astronomy, Dwingeloo, The Netherlands; University of Amsterdam, The Netherlands), Victoria M. Kaspi (McGill University), Vladislav I. Kondratiev (ASTRON; Lebedev Physical Institute, Moscow, Russia), Norbert Langer (Argelander Institut für Astronomie), Thomas R. Marsh (University of Warwick, United Kingdom), Maura A. McLaughlin (West Virginia University), Timothy T. Pennucci (Department of Astronomy, University of Virginia) Scott M. Ransom (National Radio Astronomy Observatory, Charlottesville, USA), Ingrid H. Stairs (University of British Columbia, Vancouver, Canada), Joeri van Leeuwen (ASTRON; University of Amsterdam), Joris P. W. Verbiest (MPIfR), David G. Whelan (Department of Astronomy, University of Virginia).

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”.

Link:

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

Images, Video, Text, Credits: ESO / L. Calçada.

Best regards, Orbiter.ch

NASA / ESA Probe Observes Meteors Colliding With Saturn's Rings










NASA / ESA - Cassini Mission logo.

April 25, 2013


Five images of Saturn's rings, taken by NASA's Cassini spacecraft between 2009 and 2012, show clouds of material ejected from impacts of small objects into the rings. Image credit: NASA/JPL-Caltech/Space Science Institute/Cornell.

NASA's Cassini spacecraft has provided the first direct evidence of small meteoroids breaking into streams of rubble and crashing into Saturn's rings.

These observations make Saturn's rings the only location besides Earth, the moon and Jupiter where scientists and amateur astronomers have been able to observe impacts as they occur. Studying the impact rate of meteoroids from outside the Saturnian system helps scientists understand how different planet systems in our solar system formed.


Image above: The meteoroids that NASA's Cassini spacecraft detected crashing into Saturn's rings are comparable in size to the meteor that hurtled over Russia in February 2013. Image credit: Copyright M. Ahmetvaleev.

The solar system is full of small, speeding objects. These objects frequently pummel planetary bodies. The meteoroids at Saturn are estimated to range from about one-half inch to several yards (1 centimeter to several meters) in size. It took scientists years to distinguish tracks left by nine meteoroids in 2005, 2009 and 2012.

Details of the observations appear in a paper in the Thursday, April 25 edition of Science.

Results from Cassini have already shown Saturn's rings act as very effective detectors of many kinds of surrounding phenomena, including the interior structure of the planet and the orbits of its moons. For example, a subtle but extensive corrugation that ripples 12,000 miles (19,000 kilometers) across the innermost rings tells of a very large meteoroid impact in 1983.

"These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth -- two very different neighborhoods in our solar system -- and this is exciting to see," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It took Saturn's rings acting like a giant meteoroid detector -- 100 times the surface area of the Earth -- and Cassini's long-term tour of the Saturn system to address this question."


This illustration depicts the shearing of an initially circular cloud of debris as a result of the particles in the cloud having differing orbital speeds around Saturn. Image credit: NASA/Cornell.

The Saturnian equinox in summer 2009 was an especially good time to see the debris left by meteoroid impacts. The very shallow sun angle on the rings caused the clouds of debris to look bright against the darkened rings in pictures from Cassini's imaging science subsystem.

"We knew these little impacts were constantly occurring, but we didn't know how big or how frequent they might be, and we didn't necessarily expect them to take the form of spectacular shearing clouds," said Matt Tiscareno, lead author of the paper and a Cassini participating scientist at Cornell University in Ithaca, N.Y. "The sunlight shining edge-on to the rings at the Saturnian equinox acted like an anti-cloaking device, so these usually invisible features became plain to see."

Tiscareno and his colleagues now think meteoroids of this size probably break up on a first encounter with the rings, creating smaller, slower pieces that then enter into orbit around Saturn. The impact into the rings of these secondary meteoroid bits kicks up the clouds. The tiny particles forming these clouds have a range of orbital speeds around Saturn. The clouds they form soon are pulled into diagonal, extended bright streaks.

"Saturn's rings are unusually bright and clean, leading some to suggest that the rings are actually much younger than Saturn," said Jeff Cuzzi, a co-author of the paper and a Cassini interdisciplinary scientist specializing in planetary rings and dust at NASA's Ames Research Center in Moffett Field, Calif. "To assess this dramatic claim, we must know more about the rate at which outside material is bombarding the rings. This latest analysis helps fill in that story with detection of impactors of a size that we weren't previously able to detect directly."

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

For images of the impacts and information about Cassini, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Images, Text, Credits: NASA / Dwayne Brown / JPL / Jia-Rui Cook.

Greetings, Orbiter.ch

Galileo starts to tell UTC, the world’s time












ESA - GALILEO Mission logo.

25 April 2013

Europe’s four Galileo satellites are now working as clocks accurate to a few billionths of a second, disseminating the exact time through their signals expressed as the UTC Universal Coordinated Time global standard.

“A billionth of a second equals a nanosecond, a time interval far beyond our own human capacity of appreciation,” explains Marco Falcone, ESA’s Galileo System Manager.

Galileo for timing

“A single lightning flash across the sky during a thunderstorm lasts about ten milliseconds, which is already 10 000 000 nanoseconds. But for high-tech applications, as well as navigation services, nanosecond accuracy is essential.”

The replacement for Greenwich Mean Time, UTC is part of all our daily lives: it is the timing used for Internet, banking and aviation standards as well as precise scientific experiments, maintained by the Paris-based Bureau International de Poids et Mesures (BIPM).

The BIPM computes UTC based on inputs from collections of atomic clocks maintained by institutions around the world, including ESA’s ESTEC technical centre in Noordwijk, the Netherlands.

‘Galileo time’ is derived independently of UTC but is being kept close to it, with a precise ‘offset’ between the two values being calculated continuously and then disseminated through Galileo’s navigation message.

Galileo's UTC offset

Galileo, like all other satellite navigation systems, is based on the highly precise measurement of time. A receiver on the ground pinpoints its position by calculating how long signals from satellites in orbit take to reach it.

Matching the receiver and satellite clocks then multiplying the time taken by the speed of light gives the range between user and satellite, allowing the receiver to fix its own location relative to four or more satellites.

“Each navigation system has its internal reference system time used to synchronise all system clocks and maintain overall coherence,” adds Marco. 

“Galileo runs on Galileo System Time, GST, which is fixed on the ground at the Galileo Control Centre in Fucino, Italy, by the Precise Timing Facility, based on the average of different atomic clocks.

Galileo signals

“Strictly speaking, for navigation purposes alone this internal reference system time does not need to be in agreement with UTC at the highest level of accuracy but with this agreement being the case, it is therefore possible to immediately disseminate UTC to the users to the best  accuracy and this is the aim of Galileo.”

The offset between GST and UTC is currently estimated in Turin, Italy, by the Istituto Nazionale di Ricerca Metrologica (INRIM), where time measurements are performed every day with the most precise techniques available to check GST status.

Galileo Control Centre in Fucino

INRIM has been supporting ESA’s Galileo development since the early phases of the project. More recently INRIM has overseen the creation of a ‘Time Validation Facility’ for Galileo in collaboration with five other European time-measurement institutions: the Physikalisch Technische Bundesanstalt in Germany, the National Physics Laboratory in the UK, the Systeme de References Temps Espace/Observatoire de Paris in France, the Real Instituto y Observatorio de la Armada in Spain and Observatoire Royale de Belgique.

Each day, the most precise European clocks and national time scales are compared to GST and the offset compared to UTC is estimated and provided to the Galileo Control Centre. This offset is then uploaded to the Galileo satellites for transmission in the navigation message available to users.

As explained by Patrizia Tavella from INRIM, “The UTC value available to the user via Galileo is expected to be accurate within 26 nanoseconds, but in the last two months it was even better, with a prediction error in the last two months of less than five nanoseconds.”

Related links:

ESA’s Navigation Lab helps set global time: http://www.esa.int/Our_Activities/Space_Engineering/ESA_s_Navigation_Lab_helps_set_global_time

Galileo’s clocks: http://www.esa.int/Our_Activities/Navigation/The_future_-_Galileo/Galileo_IOV_Launch/Galileo_s_clocks

International Bureau of Weights and Measures (BIPM): http://www.bipm.org/

Istituto Nazionale di Ricerca Metrologica (INRIM): http://www.inrim.it/

Images, Text, Credit: ESA.

Cheers, Orbiter.ch

Global experts agree action needed on space debris












Space Debris.

25 April 2013

There is an urgent need to remove orbiting space debris and to fly satellites in the future without creating new fragments, Europe’s largest-ever space-debris conference announced today.

The findings from the 6th European Conference on Space Debris were released during the concluding press briefing at ESA’s European Space Operations Centre in Darmstadt, Germany.

Concept for future deorbit mission

Future space missions must be sustainable, including safe disposal when they are completed. The current levels mean that we must soon begin removing debris from orbit, with research and development urgently needed for pilot ‘cleaning’ missions.

The removal of space debris is an environmental problem of global dimensions that must be assessed in an international context, including the UN.

These results were presented to over 350 worldwide participants representing almost all the major national space agencies, industry, governments, academia and research institutes.

Expert consensus on the need to act

“There is a wide and strong expert consensus on the pressing need to act now to begin debris removal activities,” says Heiner Klinkrad, Head of ESA’s Space Debris Office.

Future debris density at poles with and without active debris removal

“Our understanding of the growing space debris problem can be compared with our understanding of the need to address Earth’s changing climate some 20 years ago.”

There was wide agreement that the continuing growth in space debris poses an increasing threat to economically and scientifically vital orbital regions.

In addition to providing daily benefits to citizens and economies, today’s satellite infrastructure has immense value. The replacement cost for the approximately 1000 active satellites in orbit today is estimated to be around €100 billion. The impact on the overall economy of losing these satellites would be several orders of magnitude higher. Society would be severely damaged.

“While measures against further debris creation and actively deorbiting defunct satellites are technically demanding and potentially costly, there is no alternative to protect space as a valuable resource for our critical satellite infrastructure,” he notes.

“Their direct costs and the costs of losing them will by far exceed the cost of remedial activities.”

The findings were delivered by senior researchers and specialists from the DLR German Aerospace Center, France’s CNES space agency, Italy’s ASI space agency, the UK Space Agency, the Committee on Space Research, the International Academy of Astronautics and ESA.

ESA accelerates space debris research and development

Satellite operators worldwide, including those flying telecom, weather, navigation, broadcast and climate-monitoring missions, are now focusing their efforts on controlling space debris.

The ultimate goal is to prevent a cascade of self-sustaining collisions from setting in over the next few decades.

ESA, as a space technology and operations agency, has identified the development of active removal technologies as a strategic goal.

Sixth European Conference on Space Debris

A number of long-standing space debris-related research activities are being reinforced by the Agency. This includes improving our understanding of the debris environment and its evolution using novel, sensitive measurements and improved modelling of debris sources.

The new Clean Space initiative includes maturing technology to approach, capture and deorbit targets – a mission is already under study.

Clean Space will also develop techniques to mitigate the problem, such as passive and active deorbiting devices and the means to ‘passivate’ retiring satellites.

More information:

International Academy of Astronautics: http://www.iaaweb.org/

Background for media briefing 2013 Space Debris conference (PDF): http://www.slideshare.net/esaops/backgrounder-media-briefing-at-6th-european-conference-on-space-debris

Background:

About debris: http://www.esa.int/Our_Activities/Operations/Space_Debris/Global_experts_agree_action_needed_on_space_debris

Analysis and prediction: http://www.esa.int/Our_Activities/Operations/Space_Debris/Analysis_and_prediction

Scanning & observing: http://www.esa.int/Our_Activities/Operations/Space_Debris/Scanning_observing

Re-entry and collision avoidance: http://www.esa.int/Our_Activities/Operations/Space_Debris/Re-entry_and_collision_avoidance

Mitigating space debris generation: http://www.esa.int/Our_Activities/Operations/Space_Debris/Mitigating_space_debris_generation

Debris removal: http://www.esa.int/Our_Activities/Operations/Space_Debris/Debris_removal

Hypervelocity impacts and protecting spacecraft: http://www.esa.int/Our_Activities/Operations/Space_Debris/Hypervelocity_impacts_and_protecting_spacecraft

International cooperation: http://www.esa.int/Our_Activities/Operations/Space_Debris/International_cooperation

Images, Text, Credits: ESA / J. Mai.

Best regards, Orbiter.ch

mercredi 24 avril 2013

Russian Space Freighter Heads to ISS Despite Antenna Glitch










ROSCOSMOS - Russian Vehicle patch.

April 24, 2013

The unmanned Russian Progress-M19M cargo spacecraft is continuing its journey to the International Space Station (ISS) despite its failure to deploy one of its navigation antennas, Russia’s Mission Control said on Wednesday.

Progress-M19M launch

“Our main goal is to ensure that the spacecraft arrives at the orbital station,” a Mission Control spokesman said.

“We have failed so far to deploy the antenna [after two attempts], but we consider this a secondary issue at this point,” the official said.

The Progress M-19M freighter was launched earlier today from the Baikonur space center in Kazakhstan.

Russia’s Federal Space Agency Roscosmos reported a failure to deploy an antenna of the Kurs navigation system responsible for guiding the spacecraft to the docking module on the ISS shortly after the freighter reached the desired orbit.

Progress-M navigation antennas

The Progress-M19M is expected to reach the orbital outpost on April 26, making dozens of revolutions around the Earth before arriving at the ISS.

Russian space experts will continue to analyze the situation and attempt to fix the antenna glitch every 90 minutes, the spokesman said, adding that if continuing attempts are unsuccessful, the craft can dock automatically.

The Progress is on a resupply mission to deliver over 2.5 tons of cargo to the ISS, including payloads for the crew’s work and fuel for the space station, as well as food supplies, water and oxygen for the crew.

For more information about the Russian Federal Space Agency (ROSCOSMOS), visit: http://www.federalspace.ru/main.php?lang=ru

Images, Text, Credits: ROSCOSMOS / Orbiter.ch Aerospace / RIA Novosti.

Greetings, Orbiter.ch

Launch of the space rocket Soyuz-U with THC Progress M-19M










ROSCOSMOS - Russian Vehicles patch.

April 24, 2013

 Progress M-19M launch

Carrier rocket Soyuz-U brought transport cargo ship Progress M-19M into orbit, where it is two days to get to the International Space Station (ISS). "There was a cargo ship from the third stage rocket", - stated in the Federal Space Agency.

video
Launch of the space rocket Soyuz-U with THC Progress M-19M

It is interesting that the "Progress M-19M" will fly to the station is not six o'clock (already flown several ships), but under the old scheme - two days. It is expected that the docking of Progress to the service module Zvezda will happen on Friday, April 26 at 16:26 Moscow time. With the cargo ship to the ISS will be delivered about 2.5 tons of cargo, including fuel to maintain orbit of the station, scientific equipment for the crew, as well as food, water and air for cosmonauts and astronauts.

Progress M-19M schema launch

On the eve of the head of the nutrition department of the Institute of Biomedical Problems, Russian Academy of Sciences Alexander Agureev told Interfax that astronauts receive the products they ordered, as well as fresh fruits and vegetables. "It's apples, grapefruit, oranges, lemons, onions. On request, we send to the station sausages with garlic and chili pepper" - listed Agureev.


Start of Progress M-19M was approved on April 24, so as not to interfere with a satellite launch biological "Bion-M", held on April 19.

ROSCOSMOS Press Release (in Russian): http://www.federalspace.ru/main.php?id=2&nid=20059

Images, Video, Text, Credits: ROSCOSMOS / ROSCOSMOS TV / G. De Chiara, Mars Center / Translation: Orbiter.ch Aerospace.

Greetings, Orbiter.ch

mardi 23 avril 2013

CERN - CMS prepares for the future












CERN - European Organization for Nuclear Research logo.

April 23, 2013


Image above: Disc three, equipped with the muon chambers for the third muon station, was lowered into position in November 2006 (Image: CERN).

While the Large Hadron Collider (LHC) takes a break for its first long shutdown, the CMS collaboration are busy maintaining and consolidating the detector to be sure to handle the collider’s improved performance from 2015 onwards.

The biggest priority for CMS is the tracker performance. The CMS tracking system forms the innermost subdetector and fits snugly round the LHC beampipe. It must withstand an onslaught of some 1010 particles a second and the aggressive field of mixed radiation that this produces.

Another major element is to improve the muon detectors with a fourth endcap layer to help discriminate between interesting muons and fake signatures or background. New shielding discs, 10 centimetres deep, are to be installed on either end of the detector. Each shielding disc is made of 12 iron sector-casings filled with a special concrete. The concrete, developed for this specific application by CERN’s civil engineers, is almost 50% denser than normal concrete – it is made using haematite (or ferric oxide) instead of the usual sand – and it is loaded with boron to absorb low-energy neutrons that would otherwise give rise to unwanted hits in the detector.

The CMS detector description (click on the image for enlarge)

The new 100-tonne shielding discs represent the first large mechanical elements of CMS to be constructed entirely underground in the experimental cavern. Each disc will have to be taken apart into its 12 component sectors for lowering and then be rebuilt in a vertical position underground. The shielding discs will have an installed clearance to the new detector layer of around 10–20 millimetres, so it will be a delicate operation and the logical course of action is to install the discs before the detectors.

The schedule for 2013 is planned in fine detail with a list of hundreds of tasks that are currently being translated into day-to-day planning schematics. Amid this important technical work, the CMS collaboration will attempt to welcome around 20,000 visitors to the site at Point 5 over the course of the year. The coming two years might be described as a shutdown period for the LHC and its experiments, but life at Point 5 will be as busy as it has ever been.

This edited extract is from an article in the CERN Courier April issue. Read the full article: http://cerncourier.com/cws/article/cern/52743

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 links:

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

CMS: http://home.web.cern.ch/about/experiments/cms

Images, Text, Credits: CERN /  Austin Ball, Achintya Rao.

Cheers, Orbiter.ch

Hubble Captures Comet ISON











NASA - Hubble Space Telescope patch.

April 23, 2013


Image above: NASA’s Hubble Space Telescope provides a close-up look of Comet ISON (C/2012 S1), as photographed on April 10, when the comet was slightly closer than Jupiter’s orbit at a distance of 386 million miles from the sun. Credit:NASA, ESA, J.-Y. Li (Planetary Science Institute), and the Hubble Comet ISON Imaging Science Team.

This NASA Hubble Space Telescope image of Comet (C/2012 S1) ISON was photographed on April 10, when the comet was slightly closer than Jupiter’s orbit at a distance of 386 million miles from the Sun (394 million miles from Earth).

Even at that great distance the comet is already active as sunlight warms the surface and causes frozen volatiles to sublimate. A detailed analysis of the dust coma surrounding the solid, icy nucleus reveals a strong, jet blasting dust particles off the sunward-facing side of the comet’s nucleus.

Preliminary measurements from the Hubble images suggest that the nucleus of ISON is no larger than three or four miles across. This is remarkably small considering the high level of activity observed in the comet so far, said researchers. Astronomers are using these images to measure the activity level of this comet and constrain the size of the nucleus, in order to predict the comet’s activity when it skims 700,000 miles above the sun's roiling surface on November 28.

The comet’s dusty coma, or head of the comet, is approximately 3,100 miles across, or 1.2 times the width of Australia. A dust tail extends more than 57,000 miles, far beyond Hubble’s field of view.

More careful analysis is currently underway to improve these measurements and to predict the possible outcome of the sungrazing perihelion passage of this comet.

This image was taken in visible light. The blue false color was added to bring out details in the comet structure.

Hubble Space Telescope. Image credit: NASA / ESA

ISON stands for International Scientific Optical Network, a group of observatories in ten countries who have organized to detect, monitor, and track objects in space. ISON is managed by the Keldysh Institute of Applied Mathematics, part of the Russian Academy of Sciences.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For more information about Hubble visit:

NASA Hubble sites: http://www.nasa.gov/hubble and http://hubblesite.org/

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

Images (mentioned), Text, Credit: NASA / Space Science Telescope Institute.

Greetings, Orbiter.ch

Three Years of SDO Images












NASA - Solar Dynamics Observatory (SDO) patch.

April 23, 2013

In the three years since it first provided images of the sun in the spring of 2010, NASA’s Solar Dynamics Observatory has had virtually unbroken coverage of the sun's rise toward solar maximum, the peak of solar activity in its regular 11-year cycle. This video shows those three years of the sun at a pace of two images per day.

video
Three Years of SDO Images

Video Credit: NASA's Goddard Space Flight Center.

SDO’s Atmospheric Imaging Assembly captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 kelvins (about 1.08 million F). In this wavelength it is easy to see the sun’s 25-day rotation as well as how solar activity has increased over three years.

During the course of the video, the sun subtly increases and decreases in apparent size. This is because the distance between the SDO spacecraft and the sun varies over time. The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph and Earth orbits the sun at 67,062 mph.


Image above: This image is a composite of 25 separate images spanning the period of April 16, 2012, to April 15, 2013. It uses the SDO AIA wavelength of 171 angstroms and reveals the zones on the sun where active regions are most common during this part of the solar cycle. Credit: NASA/SDO/AIA/S. Wiessinger.

Such stability is crucial for scientists, who use SDO to learn more about our closest star. These images have regularly caught solar flares and coronal mass ejections in the act, types of space weather that can send radiation and solar material toward Earth and interfere with satellites in space. SDO’s glimpses into the violent dance on the sun help scientists understand what causes these giant explosions -- with the hopes of some day improving our ability to predict this space weather.

Solar Dynamics Observatory (SDO) spacecraft. Credit: NASA/SDO

For more information about Solar Dynamics Observatory (SDO), visit: http://sdo.gsfc.nasa.gov/ and http://www.nasa.gov/mission_pages/sdo/main/index.html

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Karen C. Fox and Scott Wiessinger.

Best regards, Orbiter.ch

Herschel links Jupiter’s water to comet impact












ESA - Herschel Mission patch.

23 April 2013

ESA’s Herschel space observatory has solved a long-standing mystery as to the origin of water in the upper atmosphere of Jupiter, finding conclusive evidence that it was delivered by the dramatic impact of comet Shoemaker-Levy 9 in July 1994.

During the spectacular week-long collision, a string of 21 comet fragments pounded into the southern hemisphere of Jupiter, leaving dark scars in the planet’s atmosphere that persisted for several weeks.

The remarkable event was the first direct observation of an extraterrestrial collision in the Solar System. It was followed worldwide by amateur and professional astronomers with many ground-based telescopes and the NASA/ESA Hubble Space Telescope.

Shoemaker-Levy 9 impact site G

ESA’s Infrared Space Observatory was launched in 1995 and was the first to detect and study water in Jupiter’s upper atmosphere. It was widely speculated that comet Shoemaker-Levy 9 may have been the origin of this water, but direct proof was missing.

Scientists were able to exclude an internal source, such as water rising from deeper within the planet’s atmosphere, because it is not possible for water vapour to pass through the ‘cold trap’ that separates the stratosphere from the visible cloud deck in the troposphere below.

Thus the water in Jupiter’s stratosphere must have been delivered from outside. But determining its origin had to wait more than 15 years, until Herschel used its sensitive infrared eyes to map the vertical and horizontal distribution of water’s chemical signature.

Herschel’s observations found that there was 2–3 times more water in the southern hemisphere of Jupiter than in the northern hemisphere, with most of it concentrated around the sites of the 1994 comet impact. Additionally, it is only found at high altitudes.

 Water in Jupiter’s atmosphere

“Only Herschel was able to provide the sensitive spectral imaging needed to find the missing link between Jupiter’s water and the 1994 impact of comet Shoemaker-Levy 9,” says Thibault Cavalié of the Laboratoire d’Astrophysique de Bordeaux, lead author of the paper published in Astronomy and Astrophysics.

“According to our models, as much as 95% of the water in the stratosphere is due to the comet impact.”

Another possible source of water would be a steady rain of small interplanetary dust particles onto Jupiter. But, in this case, the water should be uniformly distributed across the whole planet and should have filtered down to lower altitudes.

ESA’s Herschel Infrared Space Observatory

Also, one of Jupiter’s icy moons could deliver water to the planet via a giant vapour torus, as Herschel has seen from Saturn’s moon Enceladus, but this too has been ruled out. None of Jupiter’s large moons is in the right place to deliver water to the locations observed.

Finally, the scientists were able to rule out any significant contributions from recent small impacts spotted by amateur astronomers in 2009 and 2010, along with local variations in the temperature of Jupiter’s atmosphere.

Shoemaker-Levy 9 is the only likely culprit.

“All four giant planets in the outer Solar System have water in their atmospheres, but there may be four different scenarios for how they got it,” says Dr Cavalié. “For Jupiter, it is clear that Shoemaker-Levy 9 is by far the dominant source, even if other external sources may contribute also.”

Comet Shoemaker-Levy 9 approaches Jupiter

“Thanks to Herschel’s observations, we have now linked a unique comet impact – one that was followed in real time and which captured the public’s imagination – to Jupiter’s water, finally solving a mystery that has been open for nearly two decades,” adds Göran Pilbratt, ESA’s Herschel project scientist.

The observations made in this study foreshadow those planned for ESA’s future Jupiter Icy moons Explorer mission launching towards the Jovian system in 2022, where it will map the distribution of Jupiter’s atmospheric ingredients in even greater detail.

Notes for Editors:

“The spatial distribution of water in the stratosphere of Jupiter from Herschel-HIFI and –PACS observations,” by T. Cavalié et al. is published in Astronomy & Astrophysics, 553, A21, May 2013.

The observations were obtained under the Herschel Guaranteed Time Key Programme “Water and related chemistry in the Solar System”. HIFI observations were taken in July 2010 and PACS observations were made in October 2009 and December 2010.  The results were complemented with data on the stratospheric temperature of Jupiter taken at NASA’s Infrared Telescope Facility taken during the same period.

Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Related links:

Herschel: ESA's giant infrared observatory: http://www.esa.int/Our_Activities/Space_Science/Herschel

Online Showcase of Herschel Images OSHI: http://oshi.esa.int/

Herschel operations: http://www.esa.int/Our_Activities/Operations/Herschel_operations

This article in depth: http://sci.esa.int/jump.cfm?oid=51720

Read science paper: http://www.aanda.org/10.1051/0004-6361/201220797

Herschel Science Centre: http://herschel.esac.esa.int/

Images, Text, Credits: ESA / R. Evans, J. Trauger, H. Hammel and the HST Comet Science Team / Water map: ESA/Herschel/T. Cavalié et al.; Jupiter image: NASA/ESA/Reta Beebe (New Mexico State University) / Comet Shoemaker-Levy 9 approaches Jupiter: NASA, ESA, H. Weaver & E. Smith (STScI) and J. Trauger & R. Evans (Jet Propulsion Laboratory).

Best regards, Orbiter.ch