NASA Experts Continue to Engage United Nations on NASA's Asteroid Initiative

NASA logo.

February 11, 2014

Animated image above: This animated GIF shows Asteroid 2014 AA, discovered by the NASA-sponsored Catalina Sky Survey on Jan. 1, 2014, as it moved across the sky. Image Credit: CSS/LPL/UA.

In June of last year, NASA Administrator Charlie Bolden spoke to the United Nations Committee on Peaceful Uses of Outer Space (COPUOS) and shared with the international community what NASA is doing to detect and track asteroids. He also engaged the United Nation’s support for NASA’s mission to find, capture and redirect an asteroid to lunar orbit, and then send humans to explore it by 2025.

Following Bolden’s presentation, Mazlan Othman, director of the U.N. Office for Outer Space Affairs, offered support for NASA’s asteroid initiative and noted that near-Earth objects (NEO) have long been a concern for COPUOS.

This week at the COPUOS Scientific and Technical Subcommittee (STSC) in Vienna, Austria, two NASA experts provided an update about additional efforts NASA is taking to support the global effort to find, characterize, and monitor near-Earth asteroids.

Jason Kessler, program executive for the Asteroid Grand Challenge, gave a presentation on the grand challenge to the subcommittee. Kessler spoke about the critical need for international cooperation in order to meet the grand challenge, which is to find all asteroid threats to human population and know what to do about them.

Asteroid Grand Challenge animated logo

At their 2013 meeting, COPUOS endorsed expanded efforts for an International Asteroid Warning Network. IAWN is a global network of telescopes and tracking stations from different parts of the world searching all parts of the sky to provide a more comprehensive picture of how many asteroids exist and where they are. The IAWN provides a way for additional nations to join the effort.

Lindley Johnson, the program executive for the Near-Earth Object Observations (NEOO) program, spoke to the subcommittee about the progress accomplished in the last year on the IAWN and the hazardous NEO Space Mission Planning Advisory Group (SMPAG), which COPUOS also endorsed in 2013. The SMPAG is a new forum for space capable nations to discuss ways to deflect an asteroid that might impact the Earth. NASA supported the first IAWN Steering Committee meeting in January, as well as the first SMPAG meeting held in early February. The IAWN and the SMPAG are independent of the United Nations, but keep the STSC updated on their activities.

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground and space-based telescopes. The NEOO program, commonly called "Spaceguard," discovers these objects, characterizes a subset that are of interest and plots their orbits into the future to determine whether any could be potentially hazardous to our planet.

As of Feb. 1, 10,685 NEOs have been discovered, including about 97 percent of asteroids larger than .6 miles (one kilometer). But there is a greater need to pinpoint smaller asteroids such as the one that impacted near Chelyabinsk, Russia.

Near-Earth Asteroid Census

NASA is mainly focused on finding asteroids larger than 459 feet (140 meters), and creating new ways to find even smaller NEOs. NASA also is committed to developing new ways to search existing data to find these objects. In September 2013, NASA announced a partnership with Planetary Resources to develop crowd-sourced software solutions to enhance detection of NEOs in data already collected by NASA and agency partners.

NASA doubled the money spent in the search for potentially hazardous asteroids through the NEOO program in Fiscal Year 2014, and is committed to developing new ways to use existing data by seeking for innovative ideas from citizen scientists.

Data from the search for NEOs also is being used to support the Asteroid Redirect Mission. The mission concept is to use a robotic spacecraft to capture a small near-Earth asteroid -- 13-32 feet (4-10 meters) in size -- or remove a boulder 3-16 feet (1-5 meters) from the surface of a larger asteroid and redirect it into a stable orbit around the moon. Astronauts launched aboard NASA's new Orion spacecraft and Space Launch System rocket would rendezvous with the captured asteroid material in lunar orbit and collect samples for return to Earth.

One of the first steps for the asteroid redirect mission is to find a target asteroid appropriate for capture and redirection -- a step that meshes with the grand challenge effort to find all asteroid threats to human populations.

These two efforts are part of NASA’s Asteroid Initiative, which will leverage and integrate NASA’s activities in human exploration, space technology, and space science. The goal is to advance the technologies and capabilities needed for future human and robotic exploration, enable the first human mission to interact with asteroid material, and accelerate efforts to detect, track, characterize, and mitigate the threat of potentially hazardous asteroids.

More about:

Send humans to explore it by 2025: http://www.nasa.gov/mission_pages/asteroids/initiative/index.html#.UvpbuiRsiCY

Asteroid Grand Challenge: http://agcnotes.wikispaces.com/

Near-Earth Object Observations (NEOO) program: http://neo.jpl.nasa.gov/

Images, Text, Credits: NASA.

Greetings, Orbiter.ch

Progress M-20M completed flight

ROSCOSMOS - Russian Vehicles patch.

Feb. 11, 2014

February 11 planned reduction of the orbit and flooding cargo vehicle (THC) Progress M-20M. According to preliminary data, in accordance with the program laid down in the ship's on-board computer specialists Mission Control Center (MCC ) FSUE TsNIIMash, including its propulsion system is scheduled for 19 hours. 06 minutes. 30 sec., And the decline of non-combustible parts in a predetermined area of the South Pacific in the 19th hour. 54 minutes. 32 seconds. Moscow time.

Image above: The intense heat and plasma trail created as the Soyuz descent module re-enters the earths atmosphere at more than 27,000km/h.

February 3, 2014 TGC Progress M-20M nominally undocked from the docking bay (DC1) Pierce the Russian segment of the International Space Station.

Russian Cargo Ship Leaves Space Station, Another on the Way

February 11 19:54 MSK in a predetermined area of the South Pacific produced flooding incombustible residue cargo vehicle (THC) Progress M-20M. At 19:06 MSK in accordance with the program laid down in the ship's on-board computer specialists Mission Control Center (MCC) FSUE TsNIIMash on "space truck" was included on the inhibition of the propulsion system, and then began a controlled reduction of THC from orbit.

Progress M-20M undocking

During autonomous flight with TGC February 8 to 10 sessions were held space experiment bend, the purpose of which was the development of methods for the control and motion analysis of THC in gravitational orientation modes (GO) and POPs (Sun-to-Earth).

Progress M-20M undocking

TGC Progress M-20M was launched to the International Space Station from the Baikonur Cosmodrome July 28, 2013 and 2366 kg of cargo delivered .

ROSCOSMOS Press Releases: http://www.federalspace.ru/20212/ & http://www.federalspace.ru/20213/

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

Cheers, Orbiter.ch

NASA & ESA Spacecraft Get a 360-Degree View of Saturn's Auroras

NASA & ESA - Cassini Mission to Saturn patch.

February 11, 2014

Dance of Saturn's Auroras

Video above: Ultraviolet and infrared images from NASA's Cassini spacecraft and Hubble Space Telescope show active and quiet auroras at Saturn's north and south poles.

NASA trained several pairs of eyes on Saturn as the planet put on a dancing light show at its poles. While NASA's Hubble Space Telescope, orbiting around Earth, was able to observe the northern auroras in ultraviolet wavelengths, NASA's Cassini spacecraft, orbiting around Saturn, got complementary close-up views in infrared, visible-light and ultraviolet wavelengths. Cassini could also see northern and southern parts of Saturn that don't face Earth.

The result is a kind of step-by-step choreography detailing how the auroras move, showing the complexity of these auroras and how scientists can connect an outburst from the sun and its effect on the magnetic environment at Saturn.

"Saturn's auroras can be fickle -- you may see fireworks, you may see nothing," said Jonathan Nichols of the University of Leicester in England, who led the work on the Hubble images. "In 2013, we were treated to a veritable smorgasbord of dancing auroras, from steadily shining rings to super-fast bursts of light shooting across the pole."

Pulses from the Sun

Image above: The dark region seen on the face of the sun at the end of March 2013 is a coronal hole (just above and to the right of the middle of the picture), which is a source of fast solar wind leaving the sun. Image Credit: NASA/SDO/AIA.

The Hubble and Cassini images were focused on April and May of 2013. Images from Cassini's ultraviolet imaging spectrometer (UVIS), obtained from an unusually close range of about six Saturn radii, provided a look at the changing patterns of faint emissions on scales of a few hundred miles (kilometers) and tied the changes in the auroras to the fluctuating wind of charged particles blowing off the sun and flowing past Saturn.

"This is our best look yet at the rapidly changing patterns of auroral emission," said Wayne Pryor, a Cassini co-investigator at Central Arizona College in Coolidge, Ariz. "Some bright spots come and go from image to image. Other bright features persist and rotate around the pole, but at a rate slower than Saturn's rotation."

The UVIS images, which are also being analyzed by team associate Aikaterini Radioti at the University of Liege, Belgium, also suggest that one way the bright auroral storms may be produced is by the formation of new connections between magnetic field lines. That process causes storms in the magnetic bubble around Earth. The movie also shows one persistent bright patch of the aurora rotating in lockstep with the orbital position of Saturn's moon Mimas. While previous UVIS images had shown an intermittent auroral bright spot magnetically linked to the moon Enceladus, the new movie suggests another Saturn moon can influence the light show as well.

The new data also give scientists clues to a long-standing mystery about the atmospheres of giant outer planets.

"Scientists have wondered why the high atmospheres of Saturn and other gas giants are heated far beyond what might normally be expected by their distance from the sun," said Sarah Badman, a Cassini visual and infrared mapping spectrometer team associate at Lancaster University, England. "By looking at these long sequences of images taken by different instruments, we can discover where the aurora heats the atmosphere as the particles dive into it and how long the cooking occurs."

Saturn's Colorful Aurora

Image above: While the curtain-like auroras we see at Earth are green at the bottom and red at the top, NASA's Cassini spacecraft has shown us similar curtain-like auroras at Saturn that are red at the bottom and purple at the top. Image Credit: NASA/JPL-Caltech/SSI.

The visible-light data have helped scientists figure out the colors of Saturn's auroras. While the curtain-like auroras we see at Earth are green at the bottom and red at the top, Cassini's imaging cameras have shown us similar curtain-like auroras at Saturn that are red at the bottom and purple at the top, said Ulyana Dyudina, an imaging team associate at the California Institute of Technology, Pasadena, Calif.

The color difference occurs because Earth's auroras are dominated by excited nitrogen and oxygen molecules, and Saturn's auroras are dominated by excited hydrogen molecules.

"While we expected to see some red in Saturn's aurora because hydrogen emits some red light when it gets excited, we also knew there could be color variations depending on the energies of the charged particles bombarding the atmosphere and the density of the atmosphere," Dyudina said. "We were thrilled to learn about this colorful display that no one had seen before."

Scientists hope additional Cassini work will illuminate how clouds of charged particles move around the planet as it spins and receives blasts of solar material from the sun.

"The auroras at Saturn are some of the planet's most glamorous features – and there was no escaping NASA's paparazzi-like attention”, said Marcia Burton, a Cassini fields and particles scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who is helping to coordinate these observations. "As we move into the part of the 11-year solar cycle where the sun is sending out more blobs of plasma, we hope to sort out the differences between the effects of solar activity and the internal dynamics of the Saturn system."

 NASA & ESA Cassini spacecraft. Image Credit: NASA/ESA

There is still more work to do. A group of scientists led by Tom Stallard at the University of Leicester is busy analyzing complementary data taken during the same time window by two ground-based telescopes in Hawaii -- the W.M. Keck Observatory and NASA's Infrared Telescope Facility. The results will help them understand how particles are ionized in Saturn's upper atmosphere and will help them put a decade of ground-based telescope observations of Saturn in perspective, because they can see what disturbance in the data comes from Earth's atmosphere.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, Pasadena, manages the mission for NASA's Science Mission Directorate in Washington. More information about Cassini is available at: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

Images (mentioned), Video (mentioned), Text, Credits: NASA / JPL / Jia-Rui Cook.

Best regards, Orbiter.ch

Landsat 8's First Year

NASA / USGS - LDCM Mission patch.

Feb. 11, 2014

One of the first complete views of the United States from Landsat 8. Image Credit: NASA/David Roy

On Feb. 11, 2013, the Landsat 8 satellite rocketed into a sunny California morning onboard a powerful Atlas V and began its life in orbit. In the year since launch, scientists have been working to understand the information the satellite has been sending back. Some have been calibrating the data—checking it against ground observations and matching it to the rest of the 42-year-long Landsat record. At the same time, the broader science community has been learning to use the new data.

The map above—one of the first complete views of the United States from Landsat 8—is an example of how scientists are testing Landsat 8 data. David Roy, a co-leader of the USGS-NASA Landsat science team and researcher at South Dakota State University, made the map with observations taken during August 2013 by the satellite’s Operational Land Imager.

The strips in the image above are a result of the way Landsat 8 operates. Like its predecessors, Landsat 8 collects data in 185-kilometer (115-mile) wide strips called swaths or paths. Each orbit follows a predetermined ground track so that the same path is imaged each time an orbit is repeated. It takes 233 paths and 16 days to cover all of the land on Earth. This means that every land surface has the potential to be imaged once every 16 days, giving Roy two or three opportunities to get a cloud-free view of each pixel in the United States in a month.

Landsat's Orbit

Video above: In the year since its launch, Landsat 8 has made 5,319 orbits of Earth, capturing images of the land surface below. Here, Landsat 8 project scientist Jim Irons explains how those orbits capture the whole planet in 16 days. Image Credit: NASA's Goddard Space Flight Center.

Landsat 8 then joined its predecessor satellites to provide a continuous record of change across Earth's land surfaces since 1972.

Orbiting about 440 miles (705 km) above Earth, Landsat satellites document natural processes such as volcanic eruptions, glacial retreat, floods and forest fires, as well as human-induced processes such as urban expansion, crop irrigation and forest clear-cutting.

"Data produced by Landsat plays a vital role in managing America’s natural resources and the industries and jobs that rely on those resources," said Sen. Barbara Mikulski, chairwoman of the Senate Appropriations Committee that funds NASA and USGS. "It was Landsat that brought home the severity of Midwest floods in the 1990s, and it has helped identify periods of severe drought that were so devastating to our farmers and foresters. My hat goes off to NASA's Goddard Space Flight Center that has played a key role in building each of the Landsat satellites, including Landsat 8, improving each satellite with the latest technology and help us better understand planet Earth."

A high-flying rookie season

Landsat 8 is acquiring around 550 images per day – significantly more than the 400-image-per-day design requirement. Between Landsat 7 (launched in 1999 and still active) and Landsat 8, nearly 1,000 images per day are being collected. This is almost double the imagery collected three years ago, when Landsat 5 and 7 were operating together. The ability of Landsat 8 to image more frequently in persistently cloudy areas (e.g., humid tropics, high latitudes) is improving data collection in areas of critical importance for climate studies.

Landsat 8's robust data processing system also enables images to be available for public use within five hours of their arrival at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center in Sioux Falls, S.D. Since 2008, all Landsat data is free to all. Enhanced Landsat 8 data have quickly found their way into a wide range of operational applications, including forest health monitoring by the U.S. Forest Service, burn severity mapping by the USGS, NASA and the National Park Service, and cropland mapping by the National Agricultural Statistical Service.

"Before launch, I stated that Landsat 8 would be the best Landsat satellite yet — and I think the first year has proven that," said James Irons, Landsat 8 project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "Scientists are very pleased with the results. They can see more detail and can identify land cover more easily."

In land cover classification tests, conducted by Curtis Woodcock of Boston University, the Landsat 8 classification results were 19.5 percent more accurate than those developed from Landsat 7. Australian researchers are finding that improved Landsat 8 data have enhanced their ability identify and quantify areas of land degradation or improvement in the extensive Australian outback.

"Landsat 8's geometric and geodetic accuracy is so good that the USGS now has the means to use Landsat 8 data to significantly improve the geometric accuracy of the entire 4.6 million image Landsat archive," Tom Loveland, USGS-EROS senior scientist, noted. "That's a rare bonus — to be able to improve the historical record."

With the help of Landsat 8's thermal imagery, Ted Scambos and University of Colorado, Boulder, researchers found locations in eastern Antarctica that were several degrees colder than the -128.6 F (-89.2 C) record set in 1983.

A combined effort of two teams

During the past 12 months, the USGS-EROS Center and NASA Goddard have worked in close collaboration — putting the new satellite through its paces by steering it into its orbit, calibrating its detectors, collecting test images and certifying the mission for sustained operation.

As partners in the Landsat program since its inception in the 1960s, USGS and NASA have distinct roles. NASA develops remote-sensing instruments and spacecraft, launches the Landsat satellites and validates their performance. The USGS then assumes ownership and operation of the Landsat satellites, in addition to managing ground-data reception, archiving, product generation and distribution.

Artist concept of Landsat 8. Image Credit: NASA's Goddard Space Flight Center

"The Landsat archive, reaching back across four decades, provides an unprecedented record of land-surface change," said NASA Goddard Center Director Chris Scolese. "The Landsat program's success is largely due to the great partnership between NASA and the USGS. Every day we are building and strengthening that partnership, which will undoubtedly contribute to the success of future missions."

"NASA's successful development and launch of Landsat 8, the rapidly increasing volume of image data distributed by the USGS to research and operational users worldwide, and the administration's identification of Landsat as one of the nation's critical data streams – all of these factors have sparked renewed emphasis by the administration and the user community in securing uninterrupted access to Landsat data for decades to come," said USGS-EROS Director Frank Kelly. "Both NASA Goddard and the USGS-EROS Center have developed and maintained unique capabilities, where each center leverages on the strength and expertise of the other, avoiding duplication and ensuring the success of each mission."

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

For more information about NASA's Earth science activities in 2014, visit: http://www.nasa.gov/earthrightnow

For more information about Landsat 8, visit: http://www.nasa.gov/landsat; or http://www.landsat.gsfc.nasa.gov; or http://www.landsat.usgs.gov

​Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Kate Ramsayer / U.S. Geological Survey / Jon Campbell.

Greetings, Orbiter.ch

NASA Mars Orbiters See Clues to Possible Water Flows

NASA - Mars Reconnaissance Orbiter (MRO) patch / NASA - Mars Odyssey Mission patch.

February 10, 2014

NASA spacecraft orbiting Mars have returned clues for understanding seasonal features that are the strongest indication of possible liquid water that may exist today on the Red Planet.

The features are dark, finger-like markings that advance down some Martian slopes when temperatures rise. The new clues include corresponding seasonal changes in iron minerals on the same slopes and a survey of ground temperatures and other traits at active sites. These support a suggestion that brines with an iron-mineral antifreeze, such as ferric sulfate, may flow seasonally, though there are still other possible explanations.

Researchers call these dark flows "recurring slope lineae." As a result, RSL has become one of the hottest acronyms at meetings of Mars scientists.

Color-Coded Clues to Composition Superimposed on Martian Seasonal-Flow Image

This image above combines a photograph of seasonal dark flows on a Martian slope with a grid of colors based on data collected by a mineral-mapping spectrometer observing the same area. Image Credit: NASA/JPL-Caltech/UA/JHU-APL.

"We still don't have a smoking gun for existence of water in RSL, although we're not sure how this process would take place without water," said Lujendra Ojha, a graduate student at the Georgia Institute of Technology, Atlanta, and lead author of two new reports about these flows. He originally discovered them while an undergraduate at the University of Arizona, Tucson, three years ago, in images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.

Ojha and Georgia Tech assistant professor James Wray more recently looked at 13 confirmed RSL sites using images from the same orbiter's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) instrument. They searched for minerals that RSL might leave in their wake as a way of understanding the nature of these features: water-related or not?

They didn't find any spectral signature tied to water or salts. But they did find distinct and consistent spectral signatures of ferric and ferrous minerals at most of the sites. These iron-bearing minerals were more abundant or featured distinct grain sizes in RSL-related materials as compared to non-RSL slopes. These results are in a paper published in the journal Geophysical Research Letters.

Mars Reconnaissance Orbiter (MRO) spacecraft. Image Credit: NASA/JPL-Caltech

Ojha said, "Just like the RSL themselves, the strength of the spectral signatures varies according to the seasons. They're stronger when it's warmer and less significant when it's colder."

One possible explanation for these changes is a sorting of grain sizes, such as removal of fine dust from the surface, which could result from either a wet process or dry one. Two other possible explanations are an increase in the more-oxidized (ferric) component of the minerals, or an overall darkening due to moisture. Either of these would point to water, even though no water was directly detected. The spectral observations might miss the presence of water, because the dark flows are much narrower than the area of ground sampled with each CRISM reading. Also, the orbital observations have been made only in afternoons and could miss morning moisture.

The leading hypothesis for these features is the flow of near-surface water, kept liquid by salts depressing the freezing point of pure water. "The flow of water, even briny water, anywhere on Mars today would be a major discovery, impacting our understanding of present climate change on Mars and possibly indicating potential habitats for life near the surface on modern Mars," said Mars Reconnaissance Orbiter Project Scientist Richard Zurek, of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Warm-Season Flows on Martian Slope

Image above: Dark, seasonal flows emanate from bedrock exposures at Palikir Crater on Mars in this image from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image Credit: NASA/JPL-Caltech/Univ. of Arizona.

In related research, reported in a paper to be published by the journal Icarus next month, the Georgia Tech scientists and colleagues at the University of Arizona; U.S. Geological Survey, Flagstaff, Ariz.; and Polish Academy of Sciences, Warsaw, used the Mars Reconnaissance Orbiter and NASA's Mars Odyssey orbiter to look for patterns in where and when the dark seasonal flows exist on Mars. Their results indicate that many sites with slopes, latitudes and temperatures matching known RSL sites do not have any evident RSL.

They hunted for areas that were ideal locations for RSL formation: areas near the southern mid-latitudes on rocky cliffs. They found 200, but barely any of them had RSL. "Only 13 of the 200 locations had confirmed RSL," said Ojha. "The fact that RSL occur in a few sites and not others indicates additional unknown factors such as availability of water or salts may play a crucial role in RSL formation."

 NASA's Mars Odyssey orbiter. Image Credit: NASA/JPL-Caltech

They compared new observations with images from previous years, revealing that RSL are much more abundant some years than others.

"NASA likes to 'follow the water' in exploring the Red Planet, so we'd like to know in advance when and where it will appear," Wray said. "RSL have rekindled our hope of accessing modern water, but forecasting wet conditions remains a challenge."

JPL, a division of the California Institute of Technology, manages the Mars Reconnaissance Orbiter and Mars Odyssey projects for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems in Denver built both orbiters. The University of Arizona operates the HiRISE camera, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colo.  The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., provided and operates CRISM.

For more about NASA's Mars exploration missions, see http://www.nasa.gov/mars and http://mars.jpl.nasa.gov .  The new research reports about recurring slope lineae are available at http://wray.eas.gatech.edu/Ojha_etal2013-acceptedGRL.pdf and http://wray.eas.gatech.edu/Ojha_etal2014-acceptedIcarus.pdf

For more information about Mars Reconnaissance Orbiter (MRO), visit: http://www.nasa.gov/mission_pages/MRO/main/

For more information about 2001 Mars Odyssey Mission, visit: http://mars.jpl.nasa.gov/odyssey/ and http://www.nasa.gov/mission_pages/odyssey/

Images (mentioned), Text, Credits: NASA.

Greetings, Orbiter.ch

Galileo works, and works well

ESA - Galileo Constellation logo.


10 February 2014

The in-orbit validation of Galileo has been achieved: Europe now has the operational nucleus of its own satellite navigation constellation in place – the world’s first civil-owned and operated satnav system.

In 2011 and 2012 the first four satellites were launched into orbit. Four is the minimum number needed to perform navigation fixes.

In the following year, these satellites were combined with a growing global ground infrastructure to allow the project to undergo its crucial In-Orbit Validation phase: IOV.

Four-satellite constellation

“IOV was required to demonstrate that the future performance that we want to meet when the system is deployed is effectively reachable,” says Sylvain Loddo, ESA’s Galileo Ground Segment Manager.

“It was an intermediate step with a reduced part of the system to effectively give evidence that we are on track.”

On 12 March 2013, Galileo’s space and ground infrastructure came together for the very first time to perform the historic first determination of a ground location, taking place at ESA’s Navigation Laboratory in the ESTEC technical centre, in Noordwijk, the Netherlands.

From this point, generation of navigation messages enabled full testing of the entire Galileo system. A wide variety of tests followed, carried out all across Europe.

Galileo Validated video

“ESA and our industrial partners had teams deployed in the field continuously for test operations,” adds Marco Falcone, ESA’s Galileo System Manager.

“More than 10 000 km were driven by test vehicles in the process of picking up signals, along with pedestrian and fixed receiver testing. Many terabytes of IOV data were gathered in all.”

Test results

The single most important finding from the test results? Galileo works, and it works well. The entire self-sufficient system has been shown as capable of performing positioning fixes across the planet.

Galileo’s observed dual-frequency positioning accuracy is an average 8 m horizontal and 9 m vertical, 95% of the time. Its average timing accuracy is 10 billionths of a second – and its performance is set to sharpen as more satellites are launched and ground stations come on line.

Galileo positioning performance

For Galileo’s search and rescue function – operating as part of the existing international Cospas–Sarsat programme – 77% simulated distress locations can be pinpointed within 2 km, and 95% within 5 km.

All alerts are detected and forwarded to the Mission Control Centre within a minute and a half, compared to a design requirement of 10 minutes.

“Europe has proven with IOV that in terms of performance we are at a par with the best international systems of navigation in the world,” comments Didier Faivre, ESA Director of Galileo and Navigation-related Activities.

Next steps

Following this success, the build-up of the Galileo system can proceed to placing the remaining satellites into orbit and deploying further ground stations.

More than 10 000 km were driven during testing

The next two Galileo ‘Full Operational Capability’ satellites are currently at ESTEC, completing their testing to be cleared for flight.

Over the course of 2014, six more satellites are planned to join the existing four in three separate Soyuz launches. Galileo’s initial services are scheduled to start by the end of this year.

Galileo partners

The definition phase and the development and IOV phase of the Galileo programme were carried out by the ESA and co-funded by ESA and the European Commission.

Galileo inspection

The Full Operational Capability phase of the Galileo programme is managed and fully funded by the European Commission. The Commission and ESA have signed a delegation agreement by which ESA acts as design and procurement agent on behalf of the Commission.

More about:

Galileo fixes Europe's position in history: http://www.esa.int/Our_Activities/Navigation/Galileo_fixes_Europe_s_position_in_history

European ground stations enable Galileo search and rescue testing: http://www.esa.int/Our_Activities/Navigation/European_ground_stations_enable_Galileo_search_and_rescue_testing

Galileo achieves its first airborne tracking: http://www.esa.int/Our_Activities/Navigation/Galileo_achieves_its_first_airborne_tracking

How satellite navigation works: http://www.esa.int/Our_Activities/Navigation/The_future_-_Galileo/Galileo_IOV_Launch/How_satellite_navigation_works

Galileo on the ground: http://www.esa.int/Our_Activities/Navigation/The_future_-_Galileo/Galileo_IOV_Launch/Galileo_on_the_ground

Radio Navigation Laboratory: http://www.esa.int/Our_Activities/Navigation/ESA_Navigation_Development_Facilities_supports_new_projects

EC Galileo website: http://ec.europa.eu/enterprise/policies/satnav/galileo/index_en.htm

Images, Video, Text, Credits: ESA / P. Carril / Anneke Le Floc'h.

Best regards, Orbiter.ch

Overflowing craters

ESA - Mars Express Mission patch.

Feb. 10, 2014

The flood after the impact

Large and small, hundreds of thousands of craters scar the surface of Mars, hollowed out by a multitude of asteroids and comets that impacted the Red Planet throughout its history.

This image shows a region of the planet’s northern hemisphere known as Hephaestus Fossae – after the Greek god of fire – that was imaged by the high-resolution stereo camera on ESA’s Mars Express orbiter on 28 December 2007. The image has been coloured to indicate the elevation of the terrain: green and yellow shades represent shallow ground, while blue and purple stand for deep depressions, down to about 4 km.

Scattered across the scene are a few dozen impact craters that cover a wide range of sizes, with the largest boasting a diameter of around 20 km.

The long and intricate canyon-like features that resemble riverbeds are the phenomenal aftermath of the same fierce impacts that created the largest craters.

Artist's view of Mars Express spacecraft

When a small body such as a comet or an asteroid crashes at high speed into another object in the Solar System, the collision dramatically heats up the surface at the impact site.

In the case of the large crater seen in this image, the heat produced by such a powerful smash melted the soil – a mixture of rock, dust and also, hidden deep down, water ice – resulting in a massive overflow that flooded the surrounding environment. Before drying up, this muddy fluid carved a complex pattern of channels while making its way across the planet’s surface.

The melted rock–ice mixture also gave rise to the fluidised appearance of the debris blankets surrounding the largest crater.

Based on the lack of similar structures near the small craters in this image, scientists believe that only the most powerful impacts – those responsible for forging the largest craters – were able to dig deep enough to release part of the frozen reservoir of water lying beneath the surface.

Hephaestus Fossae perspective view

This image of Hephaestus Fossae was obtained by ESA’s Mars Express orbiter on 28 December 2007. The region is dotted with craters and channel systems and lies at about 21°N and 126°E on the Red Planet. Named after the Greek god of fire, Hephaestus Fossae extends for more than 600 km on the western flank of Elysium Mons in the Utopia Planitia region.

The surface is mostly smooth, and is covered by several small impact craters measuring 800 to 2800 m in diameter. Smaller craters are scattered across the entire region. The left side of the image shows a large impact crater measuring 20 km in diameter. Covering an area of approximately 150 sq km, a crater of this size on Earth could harbour cities such as Bonn or Kiel. In contrast to the smaller craters, it shows a blanket of ejecta with flow forms surrounding the rim.

Hephaestus Fossae perspective view

This image of Hephaestus Fossae was obtained by ESA’s Mars Express orbiter on 28 December 2007. The region is dotted with craters and channel systems and lies at about 21°N and 126°E on the Red Planet. Named after the Greek god of fire, Hephaestus Fossae extends for more than 600 km on the western flank of Elysium Mons in the Utopia Planitia region.

The surface is mostly smooth, and is covered by several small impact craters measuring 800 to 2800 m in diameter. Smaller craters are scattered across the entire region. The left side of the image shows a large impact crater measuring 20 km in diameter. Covering an area of approximately 150 sq km, a crater of this size on Earth could harbour cities such as Bonn or Kiel. In contrast to the smaller craters, it shows a blanket of ejecta with flow forms surrounding the rim.

Hephaestus Fossae perspective view

This image of Hephaestus Fossae was obtained by ESA’s Mars Express orbiter on 28 December 2007. The region is dotted with craters and channel systems and lies at about 21°N and 126°E on the Red Planet. Named after the Greek god of fire, Hephaestus Fossae extends for more than 600 km on the western flank of Elysium Mons in the Utopia Planitia region.

The surface is mostly smooth, and is covered by several small impact craters measuring 800 to 2800 m in diameter. Smaller craters are scattered across the entire region. A larger impact crater measuring 20 km in diameter is a prominent feature. Covering an area of approximately 150 sq km, this crater could harbour cities such as Bonn or Kiel. In contrast to the smaller craters, it shows a blanket of ejecta with flow forms surrounding the rim.

The large craters were formed when loose, soft material was ejected due to impact, and the smaller ones formed due to secondary impacts, when consolidated material was ejected in a ballistic path and impacted the original crater at varying distances. Most martian water exists in the form of subsurface ice. The presence of a blanket of ejecta and outflow channels around the crater suggest that the primary impact may have penetrated the surface enough to melt a buried frozen water reservoir.

For more information about Mars Express Mission, visit: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum).

Greetings, Orbiter.ch