UARS Re-Entry Expected Late Tonight, Early Saturday

NASA - Upper Atmosphere Research Satellite (UARS) Mission patch.

Sat, 24 Sep 2011

NASA's Upper Atmosphere Research Satellite, is expected to re-enter Earth's atmosphere expected late Friday, Sept. 23, or early Saturday, Sept. 24 (EDT). The risk to public safety or property is extremely small; safety is NASA's top priority.

As of 7 p.m. EDT on Sept. 23, 2011, the orbit of UARS was 90 miles by 95 miles (145 km by 150 km). Re-entry is expected between 11 p.m. Friday, Sept. 23, and 3 a.m., Sept. 24, Eastern Daylight Time (3 a.m. to 7 a.m. GMT). During that time period, the satellite will be passing over Canada, Africa and Australia, as well as vast areas of the Pacific, Atlantic and Indian oceans.

NASA UARS Satellite Reentry  

NASA's Upper Atmosphere Research Satellite, or UARS, is expected to re-enter Earth's atmosphere late Sept. 23 or early Sept. 24 Eastern Daylight Time, almost six years after the end of a productive scientific life. Although the spacecraft will break into pieces during re-entry, not all of it will burn up in the atmosphere.

The risk to public safety or property is extremely small, and safety is NASA's top priority. Since the beginning of the Space Age in the late-1950s, there have been no confirmed reports of an injury resulting from re-entering space objects. Nor is there a record of significant property damage resulting from a satellite re-entry.

It is still too early to say exactly when UARS will re-enter and what geographic area may be affected, but NASA is watching the satellite closely and will keep you informed. Visit this page for updates on the satellite's orbital track and predicted re-entry date.

› Re-Entry and Risk Assessment (498 KB PDF): http://www.nasa.gov/pdf/585584main_UARS_Status.pdf

› Frequently Asked Questions: Orbital Debris: http://www.nasa.gov/news/debris_faq.html

The updates posted here come from the Joint Space Operations Center of U.S. Strategic Command at Vandenberg Air Force Base, Calif., which works around the clock detecting, identifying and tracking all man-made objects in Earth orbit, including space junk.

The actual time of re-entry is difficult to predict because it depends on solar flux and the spacecraft's orientation as its orbit decays. As re-entry draws closer, predictions on the date will become more reliable.

Upper Atmosphere Research Satellite

Because the satellite's orbit is inclined 57 degrees to the equator, any surviving components of UARS will land within a zone between 57 degrees north latitude and 57 degrees south latitude. It is impossible to pinpoint just where in that zone the debris will land, but NASA estimates the debris footprint will be about 500 miles long.

If you find something you think may be a piece of UARS, do not touch it. Contact a local law enforcement official for assistance.

For more information about UARS, visit: http://www.nasa.gov/uars

Images, Video, Text, Credit: NASA / AGI.

Greetings, Orbiter.ch

Around the world – 50 000 times

ESA - ENVISAT Mission logo.

23 September 2011

ESA’s Envisat observation satellite yesterday completed its 50 000th circuit of Earth – travelling 2.25 billion km since its launch nearly a decade ago.

Envisat orbits our planet every 100 minutes, speeding along at more than seven kilometres per second.

During this milestone spin around the world on 22 September, the satellite passed from the Arctic to the Antarctic, catching glimpses of northern Greenland and New Zealand.

New Zealand

Launched on 28 February 2002, the lorry-sized Envisat is the largest Earth observation satellite ever built.

It is also the world’s most complex environmental satellite, with ten different instruments studying Earth’s land, oceans and atmosphere.

 Artist's impression of Envisat

They include the Medium Resolution Imaging Spectrometer, which captures images of ocean colour and land cover, like the above scene of New Zealand.

Greenland

The Advanced Synthetic Aperture Radar can be used day or night because it can see through clouds and darkness. This is particularly useful over polar regions, which are prone to long periods of bad weather and extended darkness.

Trace gases in the troposphere and stratosphere are measured globally by the Sciamachy imaging spectrometer, yielding maps of air pollution such as carbon dioxide, methane and nitrogen dioxide.

Nitrogen dioxide over China

Nitrogen dioxide – a mainly man-made gas – can cause lung damage and respiratory problems.

It also plays an important role in atmospheric chemistry because it leads to the production of ozone in the troposphere, the lowest part of the atmosphere.

Antarctic ozone hole

Envisat’s Michelson Interferometer for Passive Atmospheric Sounding monitors gases and pollutants. As one of three atmospheric instruments, it can map the levels of more than 20 trace gases, including ozone, as well as the pollutants that attack ozone.

The sensor is particularly useful for tracking the ozone hole over the Antarctic.

Mediterranean Sea

Other Envisat instruments include the Radar Altimeter, which measures surface height to an accuracy of a few centimetres, and the Advanced Along-Track Scanning Radiometer, which records global ground and sea-surface temperatures.

Related links:

Envisat Mission: http://envisat.esa.int/

Envisat images: http://www.esa.int/esa-mmg/mmg.pl?mission=Envisat&type=I

Envisat Earth Monitoring Live: http://envisat.esa.int/live/

Where is Envisat now?: http://envisat.esa.int/webcam/where_is_envisat.htm

MIRAVI: Earth live: http://miravi.eo.esa.int/en/

Images, Animation, Text, Credits: European Space Agency (ESA).

Best regards, Orbiter.ch

OPERA experiment invites scrutiny of unexpected results

CERN - European Organization for Nuclear Research logo.

23 Sep 2011


The OPERA experiment, which observes a neutrino beam from CERN 730 km away at Italy’s INFN Gran Sasso Laboratory, will present new results in a seminar at CERN today.

The OPERA result is based on the observation of over 15000 neutrino events measured at Gran Sasso, and appears to indicate that the neutrinos travel at a velocity 20 parts per million above the speed of light, nature’s cosmic speed limit. Given the potential far-reaching consequences of such a result, independent measurements are needed before the effect can either be refuted or firmly established. This is why the OPERA collaboration has decided to open the result to broader scrutiny.

Image above: A view of the OPERA detector in Gran Sasso, Italy. Neutrino beams from CERN in Switzerland are sent over 700km through the Earth's crust to the laboratory in Italy.

In order to perform this study, the OPERA Collaboration teamed up with experts in metrology from CERN and other institutions to perform a series of high precision measurements of the distance between the source and the detector, and of the neutrinos’ time of flight. The distance between the origin of the neutrino beam and OPERA was measured with an uncertainty of 20 cm over the 730 km travel path. The neutrinos’ time of flight was determined with an accuracy of less than 10 nanoseconds by using sophisticated instruments including advanced GPS systems and atomic clocks. The time response of all elements of the CNGS beam line and of the OPERA detector has also been measured with great precision.

"We have established synchronization between CERN and Gran Sasso that gives us nanosecond accuracy, and we’ve measured the distance between the two sites to 20 centimetres,” said Dario Autiero, the CNRS researcher who will give this afternoon’s seminar. “Although our measurements have low systematic uncertainty and high statistical accuracy, and we place great confidence in our results, we’re looking forward to comparing them with those from other experiments."

OPERA experiment site in Italy

“The potential impact on science is too large to draw immediate conclusions or attempt physics interpretations. My first reaction is that the neutrino is still surprising us with its mysteries.” said Ereditato. “Today’s seminar is intended to invite scrutiny from the broader particle physics community.”

The OPERA experiment was inaugurated in 2006, with the main goal of studying the rare transformation (oscillation) of muon neutrinos into tau neutrinos. One first such event was observed in 2010, proving the unique ability of the experiment in the detection of the elusive signal of tau neutrinos.

The OPERA1 experiment, which observes a neutrino beam from CERN2 730 km away at Italy’s INFN Gran Sasso Laboratory, will present new results in a seminar at CERN this afternoon at 16:00 CEST. The seminar will be webcast at http://webcast.cern.ch. Journalists wishing to ask questions may do so via twitter using the hash tag #nuquestions, or via the usual CERN press office channels.

More information:

Press release: OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran Sasso: http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html

The OPERA collaboration's result is available on the preprint server arxiv.org: http://arxiv.org/abs/1109.4897

Quantum Diaries: Elementary, my dear neutrino: http://www.quantumdiaries.org/2011/09/23/elementary-my-dear-neutrino/

Images, Text, Credit: CERN / INFN / OPERA.

Greetings, Orbiter.ch

Aquarius Yields NASA'S First Global Map Of Ocean Salinity

NASA - Aquarius / SAC-D Mission patch.

Sep. 22, 2011

NASA's new Aquarius instrument has produced its first global map of the salinity of the ocean surface, providing an early glimpse of the mission's anticipated discoveries.

Aquarius, which is aboard the Aquarius/SAC-D (Satelite de Aplicaciones Científicas) observatory, is making NASA's first space observations of ocean surface salinity variations - a key component of Earth's climate. Salinity changes are linked to the cycling of freshwater around the planet and influence ocean circulation.

"Aquarius' salinity data are showing much higher quality than we expected to see this early in the mission," said Aquarius principal investigator Gary Lagerloef of Earth & Space Research in Seattle. "Aquarius soon will allow scientists to explore the connections between global rainfall, ocean currents and climate variations."

The new map, which shows a tapestry of salinity patterns, demonstrates Aquarius' ability to detect large-scale salinity distribution features clearly and with sharp contrast. The map is a composite of the data since Aquarius became operational on Aug. 25. The mission was launched June 10 from Vandenberg Air Force Base in California. Aquarius/SAC-D is collaboration between NASA and Argentina's space agency, Comision Nacional de Actividades Espaciales (CONAE).

"Aquarius/SAC-D already is advancing our understanding of ocean surface salinity and Earth's water cycle," said Michael Freilich, director of NASA's Earth Science Division at agency headquarters in Washington. "Aquarius is making continuous, consistent, global measurements of ocean salinity, including measurements from places we have never sampled before."

To produce the map, Aquarius scientists compared the early data with ocean surface salinity reference data. Although the early data contain some uncertainties, and months of additional calibration and validation work remain, scientists are impressed by the data's quality.

"Aquarius has exposed a pattern of ocean surface salinity that is rich in variability across a wide range of scales," said Aquarius science team member Arnold Gordon, professor of oceanography at Columbia University in New York and at Lamont-Doherty Earth Observatory of Columbia University in Palisades, N.Y. "This is a great moment in the history of oceanography. The first image raises many questions that oceanographers will be challenged to explain."

The map shows several well-known ocean salinity features such as higher salinity in the subtropics; higher average salinity in the Atlantic Ocean compared to the Pacific and Indian Oceans; and lower salinity in rainy belts near the equator, in the northernmost Pacific Ocean and elsewhere. These features are related to large-scale patterns of rainfall and evaporation over the ocean, river outflow and ocean circulation. Aquarius will monitor how these features change and study their link to climate and weather variations.

Aquarius satellite

Other important regional features are evident, including a sharp contrast between the arid, high-salinity Arabian Sea west of the Indian subcontinent, and the low-salinity Bay of Bengal to the east, which is dominated by the Ganges River and south Asia monsoon rains. The data also show important smaller details, such as a larger-than-expected extent of low-salinity water associated with outflow from the Amazon River.

Aquarius was built by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., and the Goddard Space Flight Center in Greenbelt, Md., for NASA's Earth Systems Science Pathfinder Program. JPL is managing Aquarius through its commissioning phase and will archive mission data. Goddard will manage Aquarius mission operations and process science data. CONAE provided the SAC-D spacecraft and the mission operations center.

The new map is available at: http://photojournal.jpl.nasa.gov/catalog/PIA14786

For more information about Aquarius/SAC-D, visit: http://www.nasa.gov/aquarius  and http://www.conae.gov.ar/eng/principal.html

Images, Text, Credit: NASA / JPL / Goddard Space Flight Center.

Cheers, Orbiter.ch

Exploring an asteroid with the Desert RATS

NASA - "Desert" RATS patch.

22 September 2011

Earlier this month, European scientists linked up with astronauts roaming over the surface of an asteroid. Desert RATS, NASA’s realistic simulation of a future mission, this year included a European dimension for the first time.

It was not really an asteroid, but a desert near Flagstaff in Arizona, USA. Since 1999, scientists, astronauts and engineers from various NASA establishments and universities have gathered once a year to simulate human missions to the Moon and Mars.

One of two vehicles used in Desert RATS

Desert RATS – Desert Research and Technology Studies – have tested rovers, habitats, spacesuits, instruments, robots, communication systems, research methods and other technical, scientific and operational aspects of future missions.

These realistic ‘missions’ in extreme environments help to guide planning for future space exploration and build valuable experience in complex operations.

Fly me to an asteroid

This time, the crew of astronauts and geologists ‘landed’ on a nearby asteroid and ventured out on field trips – by foot and on two Space Exploration Vehicles.

Desert RATS field trip by an astronaut and geologist

For two weeks, the crew lived in a Deep Space Habitat with realistic radio links to their mother craft and mission control on Earth.

They had to cope with a two-way communications delay of 100 seconds with Earth, and limited bandwidth.

Reproducing the low gravity on an asteroid was impossible, but the ‘spacewalkers’ acted as though they were on a small body.

For instance, they had to attach themselves to the ground when they used their hammers to take geological samples – otherwise, the recoil would have sent them spinning into space.

Europe comes aboard

In last year’s DRATS, William Carey, an ESA specialist in future exploration operations strategies, was the only European in Arizona but this year a full science team was active in Europe.

Image above: Multimedia library of the Erasmus centre at ESTEC served as a base for European Desert RATS 'science backroom'.

“The simulation is similar to a cricket game: long periods of inactivity punctuated by periods of intense concentration,” explained William, referring to the long preparations.

“When the extravehicular activities began, everyone’s hearts started to beat faster.”

This was especially so in the two ‘science backrooms’, each with a team of scientists and engineers supporting one vehicle and its crew. The European scientists worked in the Erasmus backroom at ESA’s ESTEC technical centre in Noordwijk, the Netherlands which normally support science operations for the ISS.

Happy team of the ESTEC 'science backroom'

The team of 11 from Italy, France, the Netherlands, ESA and NASA communicated with the crews out in Arizona, just like a backroom would on a real asteroid mission.

“These scientists were the backup eyes and the extra brain power of the crew,” said Sylvie Espinasse, coordinator for the undertaking in ESA.

“Operating with access to real-time audio and video feeds, we could monitor astronauts and geologists in the field and communicate with them taking into account the delay.”

During the two intense days when ESTEC was online, the team tracked everything on the asteroid surface, observing what the crew was doing, trying to make geological sense of it and helping the explorers to squeeze all they could from the limited spacewalking time.

Goro Komatsu

“I enjoyed this different type of exploration tremendously,” said Goro Komatsu, a field geologist from the International Research School of Planetary Science, Italy.

He was excited when the action was interrupted during the second day by a thunderstorm: “It was very useful to learn how to face the unexpected!”

After all, on a real mission to an asteroid, there might be solar storms, hampering communications and forcing the astronauts to protect themselves.

Related links:

Desert RATS (NASA): http://www.nasa.gov/exploration/analogs/desertrats/index.html

Institut des Sciences de la Terre d'Orléans (CNRS, France): http://www.isto.cnrs-orleans.fr/

International Research School of Planetary Science (Pescara, Italy): http://www.irsps.unich.it/

Department of Petrology, Vrije Universiteit (Amsterdam, the Netherlands): http://www.falw.vu.nl/en/research/earth-sciences/petrology/index.asp

Images, Text, Credits: ESA / NASA  / F. Didot / C. Dekker / J. Myrrhe.

Greetings, Orbiter.ch

Liftoff of Ariane 5 with Arabsat-5C & SES-2

Arianespace Flight VA 204 - Ariane 5 ECA – Arabsat 5C – SES-2 poster.


September 21, 2011

Ariane Flight VA204

Arianespace’s mission with a dual-satellite payload of Arabsat-5C and SES-2 is now underway following the fifth liftoff of an Ariane 5 from Europe’s Spaceport in 2011.

Liftoff of Ariane 5 with Arabsat-5C & SES-2

Total lift performance for today’s launch is approximately 8,975 kg., with the spacecraft to be deployed during a flight lasting 35 minutes.

SES-2 will be utilized by European satellite telecommunications operator SES, and was manufactured by Orbital Sciences Corporation of the U.S.  Carrying 24 C-band and 24 Ku-band transponders, the satellite is to generate approximately five kilowatts of payload power, and will replace SES’ AMC-3 spacecraft at 87 deg. West for coverage over North America and the Caribbean.

SES-2 satellite

The SES-2 platform also is equipped with the Commercially Hosted Infrared Payload (CHIRP) sensor for the U.S. Air Force – which integrates a wide-field of view sensor.

Arabsat-5C satellite

Arabsat-5C is a multi-mission spacecraft for the Arab Satellite Communications Organization (Arabsat), designed to deliver capacity in both the C- and Ka-bands for a range of communications services.  It was manufactured in a joint effort by Europe’s EADS Astrium and Thales Alenia Space, and will be located at Arabsat’s 20 deg. East orbital position.

Related links:

EADS Astrium: http://www.astrium.eads.net/

Arabsat: http://www.arabsat.com/

SES: http://www.ses.com/

Thales Alenia Space: http://www.thalesgroup.com/Markets/Space/Home

Orbital Sciences Corporation: http://www.orbital.com/

Images, Video, Text, Credits: ARIANESPACE / Thales Alenia Space / EADS Astrium.

Greetings, Orbiter.ch

An Angry Bird in the Sky

ESO - European Southern Observatory logo.

21 September 2011

New ESO image of the Lambda Centauri Nebula

The Running Chicken Nebula

A new image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope reveals the Lambda Centauri Nebula, a cloud of glowing hydrogen and newborn stars in the constellation of Centaurus (The Centaur). The nebula, also known as IC 2944, is sometimes nicknamed the Running Chicken Nebula, from a bird-like shape some people see in its brightest region.

In the nebula, which lies around 6500 light-years from Earth, hot newborn stars that formed from clouds of hydrogen gas shine brightly with ultraviolet light. This intense radiation in turn excites the surrounding hydrogen cloud, making it glow a distinctive shade of red. This red shade is typical of star-forming regions, another famous example being the Lagoon Nebula (eso0936).

Some people see a chicken shape in pictures of this red star-forming region, giving the nebula its nickname — though there is some disagreement over exactly which part of the nebula is chicken shaped, with various bird-like features in evidence across the picture [1].

The Running Chicken Nebula in the constellation of Centaurus

Aside from the glowing gas, another sign of star formation in IC 2944 is the series of opaque black clumps silhouetted against the red background in part of this image. These are examples of a type of object called Bok globules. They appear dark as they absorb the light from the luminous background. However, observations of these dark clouds using infrared telescopes, which are able to see through the dust that normally blocks visible light, have revealed that stars are forming within many of them.

The most prominent collection of Bok globules in this image is known as Thackeray’s Globules, after the South African astronomer who discovered them in the 1950s. Visible among a group of bright stars in the upper right part of the image, these globules feature in a famous image taken by the NASA/ESA Hubble Space Telescope (link).

Zooming in on the Running Chicken Nebula

While Hubble offers greater detail in its image of this small area, the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory captures a much larger panorama in its images, covering an area of sky roughly the size of the full Moon [2]. Much like a zoom lens on a camera lets a photographer choose the most appropriate field of view when taking a picture, the dramatically different viewpoints offered by different telescopes can offer complementary data to scientists studying astronomical objects which cover an extended area of the sky.

If the stars cocooned in Thackeray’s Globules are still gestating, then the stars of cluster IC 2948, embedded within the nebula, are their older siblings. Still young in stellar terms, at just a few million years old, these stars shine brightly, and their ultraviolet radiation provides much of the energy that lights up the nebula. These glowing nebulae are relatively short-lived in astronomical terms (typically a few million years), meaning that the Lambda Centauri Nebula will eventually fade away as it loses both its gas and its supply of ultraviolet radiation.

Notes:

[1] Ideas for where the chicken outline lies on the picture can be submitted through the Your ESO Pictures Flickr group for a chance to win some interesting prizes.

[2] This image was produced as part of the ESO Cosmic Gems programme. This is a new initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of small amounts of observing time, combined with otherwise unused time on the telescopes’ schedules so as to minimise the impact on science observations. All data collected are also made available to astronomers through ESO’s science archive.

More information:

ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. 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 a 40-metre-class European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

    Hubble Space Telescope closeup of Thackeray’s Globules in the Running Chicken Nebula:    http://www.spacetelescope.org/images/opo0201a/

    ESO Cosmic Gems page: http://www.eso.org/public/outreach/gems.html

Images, Text, Credits: ESO / IAU and Sky & Telescope / Richard Hook / Video: ESO / N. Risinger (skysurvey.org) / Music: John Dyson (from the album Moonwind).

Greetings, Orbiter.ch