The IAU has been the arbiter of planetary and satellite nomenclature since its inception in 1919. In keeping with the established naming theme for rupes on Mercury, all of the newly designated features are named after ships of discovery.

"We proposed the name Enterprise Rupes for the longest rupes on Mercury, which is 820 kilometers (510 miles) long. The USS Enterprise was launched in 1874 and conducted the first surveys of the Mississippi and Amazon rivers," says Michelle Selvans of the Center for Earth and Planetary Studies at the National Air and Space Museum. Selvans led the effort to name this group of rupes.

"We also recommended some fun names, such as Calypso Rupes, for Jacques Cousteau's ship," she says. And other names were proposed for their personal connections, such as Palmer Rupes, named after an icebreaker research vessel on which Selvans sailed to conduct marine geophysics research offshore of Antarctica. The other names are

* Alvin Rupes, after DSV Alvin. Built in 1964 as one of the world's first deep-ocean submersibles, Alvin has made more than 4,400 dives. It can reach nearly 63 percent of the global ocean floor.

* Belgica Rupes, after RV Belgica. Built in 1884, this steamship was originally designed as a whaling ship. It was converted to a research ship in 1896 and took part in the Belgian Antarctic Expedition of 1897-1901, becoming the first ship to overwinter in the Antarctic.

* Carnegie Rupes, after a yacht launched in 1909 as a research vessel. The ship was built almost entirely from wood and other non-magnetic materials to allow sensitive magnetic measurements to be taken for the Carnegie Institution's Department of Terrestrial Magnetism. During 20 years at sea the vessel traveled nearly 500,000 kilometers (300,000 miles) and carried out a series of cruises until an onboard explosion in port destroyed the ship in 1929.

* Duyfken Rupes, after a small Dutch ship built in the late 16th century. In 1606, the vessel sailed from the Indonesian island of Banda in search of gold and trade opportunities on the island of Nova Guinea. Under the command of Willem Janszoon, the ship and her crew did not find gold, but they did discover the northern coast of a huge continent: Australia.

* Eltanin Rupes, after the USNS Eltanin, launched in 1957 as a noncommissioned Navy cargo ship. The vessel was built with a double hull and officially classified as an Ice-Breaking Cargo Ship. In 1962, the ship was refitted to perform research in the southern oceans and reclassified an Oceanographic Research Vessel. Magnetic field measurements made with the Eltanin were critical in validating the hypothesis of sea-floor spreading.

* Nautilus Rupes, after the Exploration Vessel Nautilus. In service since 1967, the ship has conducted underwater studies in archeology in the Mediterranean and Caribbean seas. The vessel is currently equipped with remotely operated vehicles and a high-bandwidth satellite communication system for remote science and education.

* Terror Rupes, after the HMS Terror. Built in the early 1800s as a British Royal Navy bomb vessel, the ship was involved in the bombardment of Fort McHenry, one of the last battles of the War of 1812. The bombardment provided the inspiration for Francis Scott Key to write the American national anthem "Star Spangled Banner." After being retrofitted for polar exploration, the ship participated in Antarctic exploration.

Selvans says that Mercury's rupes are revealing a great deal about the evolution of the planet. Each feature formed over a major fault system that accommodated kilometers of horizontal shortening of Mercury's crust. The accumulated contraction taken up by the faults that underlie the rupes collectively records the cooling and contraction of Mercury's interior over the past 4 billion years of planetary history.

In choosing those rupes to receive names, the team picked from among the longest and most geologically interesting features that have been imaged by MESSENGER. "These features are easy to identify in images taken at dawn and dusk, when they throw shadows along their entire length," Selvans says. "A crisp shadow that is only about 1 kilometer wide but hundreds of kilometers long really stands out in images."

Since 1976, the IAU has approved names for 27 rupes on Mercury. The latest names are the first new designations for rupes in more than five years.

"The MESSENGER team is grateful to the IAU for their approval of formal names for rupes on Mercury," adds MESSENGER Principal Investigator Sean Solomon of Columbia University's Lamont-Doherty Earth Observatory.

"MESSENGER observations have revealed that these deformational features accommodated far more crustal contraction than indicated by earlier estimates. The new names will permit the MESSENGER team to document this finding in a clear and straightforward manner. Moreover, the names give us the opportunity to recognize that the exploration of Earth's oceanic regions continues in parallel with the exploration of Earth's sister planets."

More information about the names of features on Mercury and the other objects in the Solar System can be found at the U.S. Geological Survey's Planetary Nomenclature Web site.

]]> Wed, 12 JUN 2013 00:35:24 AEST Laurel MD (SPX) May 27, 2013 - MESSENGER began its 2,000th orbit around Mercury earlier this week, on May 22. The spacecraft completed its primary mission on March 17, 2012, and its first extended mission on March 17, 2013. The team is awaiting word from NASA on a proposal for a second extended mission. In the meantime, instruments aboard the spacecraft continue to gather new data on Mercury and its environment.

From May 6 to May 14, MESSENGER traversed a superior solar conjunction, during which the spacecraft was on the far side of the Sun from Earth. Scientists used the opportunity to measure the characteristics of the solar magnetic field from the Faraday rotation of its radio-frequency carrier.

"We found the orientation of the magnetic field within a coronal mass ejection (CME) that crossed the line of sight on May 10," says Elizabeth Jensen, of the Planetary Science Institute in Tucson, Arizona.

"We saw the rotation of the plane of polarization of MESSENGER's radio-frequency signal as it moved deeper into the corona, giving information on the Sun's magnetic field configuration on May 11; and on May 12, we saw magnetohydrodynamic waves, a very important mode of energy transfer in the corona."

Solar storms cause communications disruptions, expose spacecraft and personnel in airplanes to radiation, and threaten electrical grids. Jensen says that the observations of the CME demonstrate the utility of this technique to predict the threat of solar storms headed toward Earth almost immediately after they erupt.

"Understanding the accuracy of models for the solar magnetic field and solar wind generation requires testing," she says. "Although other methods can be used in active regions, Faraday rotation is the only way to test the magnetic field models in the largest part of the corona where the solar wind is accelerating."

At its closest point to Mercury, MESSENGER will be about 447 kilometers (277.8 miles) above a point near 83.1A N latitude. Since its most recent orbit-correction maneuver on April 20, 2012, the spacecraft has completed three orbits of Mercury every day.

At this rate, says mission trajectory lead James McAdams of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, the spacecraft will reach its 3,000th orbit around Mercury on April 20, 2014.

]]> Wed, 12 JUN 2013 00:35:24 AEST St. Louis, MO (SPX) Apr 06, 2013 - Early in 2012, someone in Southern Morocco picked up 35 greenish stones, including the one shown above. Purchased by a dealer in Erfoud, Morocco, it was then resold to Stefan Ralew, a meteorite collector from Berlin.

The dealer was demanding a high price, and Ralew may have hesitated. But the wrinkled glassy coating on one face of the rock was clearly a fusion crust, a kind of glaze that forms when a meteorite is heated as it passes through the atmosphere.

Looking at other faces he would have recognized it as a type of meteorite called an achondrite, says Randy Korotev, WUSTL's meteorite expert. That meant it was an exceptional stone.

Most meteorites are stony, he explains, and of the stony meteorites, almost all (90 percent) are what are called ordinary chondrites. These are pieces of small, unmelted asteroids that are uniform in composition throughout.

The achondrites, on the other hand are pieces of large asteroids or planets, ones at least 200 kilometers in diameter. These produced enough internal heat early in their history to partially melt and segregate into a metal core surrounded by a rocky exterior.

Achondrites, which come from the crust or mantle of these differentiated bodies make up only 5 percent of the stony meteorites that have been found.

So already this find was looking very interesting. Where might it be from? About half of the achondrites come from the large asteroid 4 Vesta. Others come from Mars, the moon, or other asteroids.

To answer the question of origin, the stone's chemistry had to be analyzed. Ralew shipped it to Tony Irving at the University of Washington. "Tony is where all the serious collectors go when they find strange meteorites," says Korotev, to whom Irving sends the "lunars" (possible lunar meteorites), which is what Korotev mainly studies.

Both the iron/manganese ratio of an asteroid and the ratios of its oxygen isotopes (variants of the oxygen atom) are thought to serve as "fingerprints" of its body of origin.

At the 44th Lunar and Planetary Science Conference in March, Irving said that the stone, now officially designated Northwest Africa 7325 (NWA 7325), had highly unusual chemistry. What's more, he said, the chemistry was suspiciously similar to that measured by NASA's Messenger probe, which is currently surveying the surface of Mercury from orbit.

"It is high in magnesium and very low in iron, which is what they're seeing on the surface of Mercury," Korotev, who attended Irving's talk, says.

"But it's got more plagioclase (an aluminum containing mineral) than they're seeing on the surface of Mercury and it plots funny in 'oxygen isotope space.' It's plotting in a region of oxygen isotope space where we've never had meteorite data points before - except for a few ureilites, which also have oddball chemistry."

Some chemical ratios didn't match, but Irving said that might be because the stone had been "excavated from depth," that is blasted into space by a collision that left a deep scar in Mercury.

During the question and answer period after the talk, Tim McCoy, the curator of the meteorite collection at the Smithsonian Institution, said that preliminary data suggested the meteorite had crystallized from the melt 4.5 billion years ago.

That made it implausible it was from Mercury, he said. Lunar highland rocks are 4.2 to 4.3 billion years old and Mercurian rocks should have crystallized at the same time or later than the lunar highland rocks.

That objection was persuasive to Korotev. "The moon began to crystallize 4.5 years ago," he says, "but we don't have any 4.5-billion-year-old meteorites from the moon, because all of those rocks would have been bashed to smithereens during the late heavy bombardment that pockmarked the moon with craters between 4 to 3.8 billion years ago."

"The same thing would have happened on Mercury," he said, "so the question is how did this rock survive for that long? There's no sign of it being brecciated, or busted up. "

"But if it's not from Mercury," he said, "then where is it from? That's really the question."

"It has very odd chemistry for a meteorite," Korotev. "If somebody had walked in with this chemical analysis and nothing else I would have told him that it wasn't a meteorite, just based on the chemistry," he says laughing.

After a moment, he adds, "They haven't talked about cosmogenic radionuclides yet. That would be really interesting."

Cosmogenic radionuclides provide a method for estimating how long a rock has been exposed to solar wind particles streaming off the sun and cosmic rays. "If this stone had exceedingly high cosmogenic nuclides," Korotev said, "that would be an argument for it coming from Mercury, because Mercury is so close to the sun.

In the meantime the Meteoritical Society, which adjudicates all matters having to do with meteorites, has classified NWA 7325 as "achondrite ungrouped," meaning that they believe it is a stone from a differentiated body like a planet or big asteroid but beyond that they are agnostic.

Although Korotev can't say where the meteorite comes from, he can say why it is such a peculiar green. The green comes from a silicate mineral laced with chromium.

"I once analyzed bottles to see what made them blue or green," Korotev says. The greenest bottle had 660 parts per million chromium, but some of the mineral components of NWA 7325 have 7,000 parts per million chromium. That's why it's green."

But the bigger mystery is as yet unsolved.

]]> Wed, 12 JUN 2013 00:35:24 AEST Laurel MD (SPX) Mar 20, 2013 - On March 17, 2013, MESSENGER successfully completed its year-long first extended mission in orbit about Mercury, building on the groundbreaking scientific results from its earlier primary mission.

Now the team is poised to embark on a second extended mission that promises to provide new observations of Mercury's surface and interior at unprecedented spatial resolution and of the planet's dynamic magnetosphere and exosphere at high time resolution during the peak and declining phase of the current solar cycle.

"NASA is currently considering a second extension to mission operations and until the formal decision is made has asked that we continue to operate the spacecraft and its scientific instruments," says MESSENGER Project Manager Helene Winters of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

During its first extended mission, MESSENGER completed 12 specialized measurement campaigns that led to new discoveries about surface volatiles on Mercury, the duration of volcanism, the evolution of long-wavelength topography, the nature of localized regions of enhanced exospheric density, the effect of the solar cycle on Mercury's exosphere, and Mercury's energetic electrons.

Among the most recent results was confirmation of the long-held theory that the planet harbors abundant water ice and other frozen volatile materials within its permanently shadowed polar craters.

If approved by NASA, a second extended mission would seek answers to still further questions, each stimulated by findings from the primary mission and first extended mission, including: What active and recent processes have affected Mercury's surface?

+ How has the state of stress in Mercury's crust evolved over time?

+ How have compositions of volcanic materials on Mercury varied with time?

+ What are the characteristics of volatile sequestration in Mercury's north polar region?

+ What are the consequences of precipitating ions and energetic electrons at Mercury?

+ How do Mercury's exosphere and magnetosphere respond to extreme solar wind conditions near and following solar maximum?

+ What novel insights into Mercury's thermal and crustal evolution can be obtained from high-resolution measurements made at low altitudes?

A possible second extended mission is among the topics MESSENGER team members will be discussing on March 20 in a session at the 44th Lunar and Planetary Science Conference in The Woodlands, Texas.

"Mercury has been revealing its many secrets, but each discovery has led to new puzzles," adds MESSENGER Principal Investigator Sean Solomon, of Columbia University's Lamont-Doherty Earth Observatory.

"We now have a healthy spacecraft in orbit around a planet that will not be visited by spacecraft again for more than 10 years. Our scientific plans for a second extended mission build on past discoveries, can be accomplished with planned orbital observations, span an unprecedented phase of the solar cycle, and include extraordinarily low-altitude campaigns that will offer spectacular new views of Mercury's surface and near-surface environment. We hope that NASA will support the continued investigation of the most enigmatic of the inner planets."

]]> Wed, 12 JUN 2013 00:35:24 AEST Paris (ESA) Mar 13, 2013 - The engineering model of the BepiColombo Mercury Transfer Module has completed a 12-day Sun-simulation test inside the Large Space Simulator at ESA's test centre in the Netherlands, where it received a taste of the extreme solar heating it will experience when it enters orbit around the Solar System's innermost planet in 2022.

The image was taken during a dry run on 20 February, during which the facility's motion system replicated the different orientations of the simulated solar beam and the positions of the test table.

The real test, in vacuum, began on 26 February and continued non-stop for 12 days. During this time the module was subjected to ten times the solar heating experienced by satellites circling Earth.

Some of the 121 hexagonal mirror segments that direct the simulated solar radiation onto the spacecraft are visible towards the top of the image. The aperture through which the 'sunlight' travels from the nineteen 25 kW lamps can be seen just to the left of the mirror segments.

The Mercury Transfer Module will carry the mission's two scientific satellites - Japan's Mercury Magnetospheric Orbiter and Europe's Mercury Planetary Orbiter - into orbit around Mercury. The spacecraft will use electric propulsion to reach its destination.

In this view, one of four ion propulsion engines has already been installed (the grey cylinder close to the centre of the unit), while part of the solar array drive protrudes from the right side of the module.

Earlier this month, the mission's Mercury Planetary Orbiter Mechanical and Propulsion Bus Proto-Flight Model completed a 'bake out' in the Phenix thermal vacuum facility at ESA's ESTEC test facility. This heated the unit to 60 C in a vacuum for 23 days to remove any contaminants that would outgas in space.

BepiColombo is an international mission between ESA and the Japan's JAXA space agency. It is scheduled for launch in 2015 and will arrive at Mercury in 2022, where it will study the planet's composition, geophysics, atmosphere, magnetosphere and geological history.

]]> Wed, 12 JUN 2013 00:35:24 AEST Laurel MD (SPX) Mar 12, 2013 - NASA's Planetary Data System released a new data set collected during MESSENGER's thirteenth through eighteenth month in orbit around Mercury. With this release, images and measurements are now available to the public for the third full Mercury solar day of MESSENGER orbital operations.

NASA requires that all of its planetary missions archive data in the PDS, which makes available well-documented, peer-reviewed data to the research community. This ninth delivery of MESSENGER measurements includes raw and calibrated data from all seven of the mission's science instruments, plus radio science data from the spacecraft telecommunications system, from March 25 to September 17, 2012.

The team has also provided, for the first time in this release, advanced products created with data collected through March 25, 2012, encompassing the first two full Mercury solar days of MESSENGER orbital operations. Those products include the first global mosaics of Mercury to be delivered to PDS.

"The two advanced image products in this release are an eight-color map and a higher-resolution monochrome map," says Mercury Dual Imaging System (MDIS) Instrument Scientist Nancy Chabot, of the Johns Hopkins University Applied Physics Laboratory (APL).

"They are both the products of thousands of images mosaicked together to reveal Mercury's global geology and color characteristics. These mosaics required considerable effort by many on the MESSENGER team, and we are all very proud to make these global maps available."

Other advanced products include

+ summed gamma-ray spectra and background-subtracted, geolocated neutron counts from the Gamma-Ray and Neutron Spectrometer;

+ time-averaged magnetic field data from the Magnetometer;

+ altimeter profiles, radiometry, and a northern hemisphere digital elevation map produced with data from the Mercury Laser Altimeter (MLA);

+ limb tangent height and surface reflectance spectra from the Mercury Atmospheric and Surface Composition Spectrometer;

+ pitch-angle and measured-flux distributions and energy spectra from the Energetic Particle and Plasma Spectrometer;

+ and occultation data and spherical harmonic gravity and shape models derived from the radio science investigation and the MLA.

"Many in the public have been eagerly awaiting the release of the MESSENGER advanced products, and the MESSENGER team is excited to be able to provide them," says APL's Susan Ensor, MESSENGER's Science Operations Center lead.

"Extra analyses and processing are required to generate these products, which in many cases combine data over time and include maps, topography, and other global data. The team has also worked closely with the PDS in planning and documenting these new products to ensure their long-term usefulness to the science community."

"Mercury is a planet of many mysteries," adds MESSENGER Principal Investigator Sean Solomon, of Columbia University's Lamont-Doherty Earth Observatory. "With each increment of data, we have made discoveries that raised new questions. Finding answers to those questions requires further analysis. We hope that this latest release of MESSENGER data will induce more of our colleagues from the broader planetary science community to help us unravel the many stories that Mercury has yet to tell."

The MESSENGER mission's ACT-REACT-QuickMap software, developed by Applied Coherent Technology Corporation, allows users to examine global mosaics constructed with high-resolution images from this and previous PDS deliveries.

The tool also provides weekly updates of coverage for surface-observing instruments, as well as the status of specially targeted MDIS observations. Future enhancements to QuickMap will include simple data fusion, by which data sets from multiple elements of the payload may be combined.

]]> Wed, 12 JUN 2013 00:35:24 AEST Boston MA (SPX) Feb 27, 2013 - By analyzing Mercury's rocky surface, scientists have been able to partially reconstruct the planet's history over billions of years. Now, drawing upon the chemical composition of rock features on the planet's surface, scientists at MIT have proposed that Mercury may have harbored a large, roiling ocean of magma very early in its history, shortly after its formation about 4.5 billion years ago.

The scientists analyzed data gathered by MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging), a NASA probe that has orbited the planet since March 2011. Later that year, a group of scientists analyzed X-ray fluorescence data from the probe, and identified two distinct compositions of rocks on the planet's surface. The discovery unearthed a planetary puzzle: What geological processes could have given rise to such distinct surface compositions?

To answer that question, the MIT team used the compositional data to recreate the two rock types in the lab, and subjected each synthetic rock to high temperatures and pressures to simulate various geological processes. From their experiments, the scientists came up with only one phenomenon to explain the two compositions: a vast magma ocean that created two different layers of crystals, solidified, then eventually remelted into magma that then erupted onto Mercury's surface.

"The thing that's really amazing on Mercury is, this didn't happen yesterday," says Timothy Grove, a professor of geology at MIT. "The crust is probably more than 4 billion years old, so this magma ocean is a really ancient feature."

Grove, along with postdoc Bernard Charlier and Maria Zuber, the E.A. Griswold Professor of Geophysics and Planetary Science and now MIT's vice president for research, published the results in the journal Earth and Planetary Science Letters.

Making Mercury's rocks
MESSENGER entered Mercury's orbit during a period of intense solar-flare activity; as the solar system's innermost planet, Mercury takes the brunt of the sun's rays. The rocks on its surface reflect an intense fluorescent spectrum that scientists can measure with X-ray spectrometers to determine the chemical composition of surface materials.

As the spacecraft orbited the planet, an onboard X-ray spectrometer measured the X-ray radiation generated by Mercury's surface. In September 2011, the MESSENGER science team parsed these energy spectra into peaks, with each peak signifying a certain chemical element in the rocks. From this research, the group identified two main rock types on Mercury's surface.

Grove, Charlier and Zuber set out to find an explanation for the differences in rock compositions. The team translated the chemical element ratios into the corresponding building blocks that make up rocks, such as magnesium oxide, silicon dioxide and aluminum oxide. The researchers then consulted what Grove refers to as a "pantry of oxides" - finely powdered chemicals - to recreate the rocks in the lab.

"We just mix these together in the right proportions and we've got a synthetic copy of what's on the surface of Mercury," Grove says.

Crystals in the melt
The researchers then melted the samples of synthetic rock in a furnace, cranking the heat up and down to simulate geological processes that would cause crystals - and eventually rocks - to form in the melt.

"You can tell what would happen as the melt cools and crystals form and change the chemical composition of the remaining melted rock," Grove says. "The leftover melt changes composition."

After cooling the samples, the researchers picked out tiny crystals and melt pockets for analysis. The scientists initially looked for scenarios in which both original rock compositions might be related. For example, both rock types may have come from one region: One rock may have crystallized more than the other, creating distinct but related compositions.

But Grove found the two compositions were too different to have originated from the same region, and instead may have come from two separate regions within the planet. The easiest explanation for what created these distinct regions, Grove says, is a large magma ocean, which over time likely formed different compositions of crystals as it solidified. This molten ocean eventually remelted, spewing lava onto the surface of the planet in massive volcanic eruptions.

Grove estimates that this magma ocean likely existed very early in Mercury's existence - possibly within the first 1 million to 10 million years - and may have been created from the violent processes that formed the planet. As the solar nebula condensed, bits and pieces collided into larger chunks to form tiny, and then larger, planets. That process of colliding and accreting may produce enough energy to completely melt the planet - a scenario that would make an early magma ocean very feasible.

"The acquisition of data by spacecraft must be combined with laboratory experiments," Charlier says. "Although these data are valuable by themselves, experimental studies on these compositions enable scientists to reach the next level in the interpretation of planetary evolution."

Larry Nittler, a staff scientist in the Department of Terrestrial Magnetism at the Carnegie Institution of Washington, led the research team that originally identified the two rock compositions from MESSENGER data. He says the MIT team's experimental results propose a very likely early history for Mercury.

"We're gradually filling in more blanks, and the story may well change, but this work sets up a framework for thinking about new data," says Nittler, who was not involved in the study. "It's a very important first step toward going from exciting data to real understanding."

This research was supported by a NASA cosmochemistry grant, a Marie Curie International Outgoing Fellowship, and the NASA MESSENGER mission. Grove, along with postdoc Bernard Charlier and Maria Zuber, the E.A. Griswold Professor of Geophysics and Planetary Science and now MIT's vice president for research, published the results in the journal Earth and Planetary Science Letters.

]]> Wed, 12 JUN 2013 00:35:24 AEST Paris (ESA) Feb 06, 2013 - The BepiColombo Mercury Planetary Orbiter Mechanical and Propulsion Bus Proto-Flight Model (the structure with integrated heat pipes and chemical propulsion subsystem) has been baked out in the Phenix thermal vacuum facility at ESA's European Space Research and Technology Centre (ESTEC) in Noordwijk, the Netherlands.

The BepiColombo Mercury Planetary Orbiter (MPO) Mechanical and Propulsion Bus (MPB) Proto-Flight Model (PFM) has been baked out in the Phenix thermal vacuum facility at ESA's European Space Research and Technology Centre (ESTEC) in Noordwijk, the Netherlands. T

This process involved heating the MPB to 60C in a vacuum for 20 days to remove any contaminants that would outgas in space.

Given the extremes of temperature to which BepiColombo will be exposed - in excess of 350C on the parts illuminated by the Sun, -120C or less on the parts exposed to cold space - prevention of outgassing is important because the outgassing products from the hot areas of the spacecraft may recondense on colder areas or be photochemically deposited on Sun-illuminated surfaces by ultraviolet radiation.

Contamination of thermal control surfaces would alter their absorptivity / emissivity ratios, possibly causing an uncontrolled increase in temperature.

Contamination of the solar arrays could greatly decrease their power output, while contamination of the instruments would severely degrade their optics. Molecular contamination is caused by volatiles that are released by materials such as paints, plastics and adhesives.

The Phenix thermal vacuum facility is designed for small and medium spacecraft and subsystems. The facility consists of a cylindrical vacuum chamber nearly 12 metres long and 4.5 metres in diameter, with access gained through a 4.5-metre-diameter door. The chamber is equipped with a movable box-shaped shroud system and a movable platform on which the test item is mounted.

This design enables a quicker throughput time as the movable platform and shroud enable preparation outside the chamber and rapid loading of the facility. Phenix typically achieves a vacuum of 5 + 10-6 millibar in the absence of heavily outgassing materials.

The MPB PFM will now be transported to Thales Alenia in Turin for integration of additional equipment and subsystems. These have already been subjected to a similar outgassing treatment.

]]> Wed, 12 JUN 2013 00:35:24 AEST Washington DC (SPX) Jan 31, 2013 - With both x-ray and gamma-ray spectrometers, the MErcury Surface, Space ENvironment, GEochemistry and Ranging probe (MESSENGER), which entered orbit around Mercury in 2011, is well equipped for carrying out a detailed compositional analysis of Mercury's crust, the understanding of which could help determine the nature of the planet's formation, and of its volcanic past.

Using spectrometric measurements and laboratory analyzes of Mercury surface-analogue samples, Stockstill-Cahill et al. determine that the upper layers of Mercury's crust most closely resemble magnesian basalt terrestrial rocks, though with lower iron concentrations.

To make their determination, the authors used a software package known as MELTS to simulate the cooling and crystallization of potential Mercurian lavas with different chemical compositions, estimating the temperatures at which minerals would crystallize out of the molten lava and the abundances of different mineral species.

Similarly, the authors simulated the cooling of magnesium-rich terrestrial rocks and of meteoritic samples.

Based on their chemical compositional analysis, the authors infer a number of properties for an early lava on Mercury. They suggest that the lava would have had a very low viscosity, streaming across the surface in widespread but thin layers.

Further, they calculate that the temperatures required to produce the magnesium-rich lava would have been much higher than for terrestrial rocks not enriched in magnesium.

The authors say that the low-viscosity lava would leave telltale marks on the planet's surface that could be identified through further MESSENGER observations.

Magnesium-rich crustal compositions on Mercury: Implications for magmatism from petrologic modeling Karen R. Stockstill-Cahill and Timothy J. McCoy: Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA; Larry R. Nittler and Shoshana Z. Weider: Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, District of Columbia, USA; Steven A. Hauck, II: Department of Earth, Environmental, and Planetary Sciences, Case Western Reserve University, Cleveland, Ohio, USA. Journal of Geophysical Research-Planets, doi: 10.1029/2012JE004140, 2012 Wed, 12 JUN 2013 00:35:24 AEST Paris (ESA) Dec 18, 2012 - The mass properties of the BepiColombo Mercury Transfer Module Structural and Thermal Model have been measured. The transfer module's primary task is to provide solar-electric propulsion during the mission's journey to Mercury.

The mass properties (total mass, centre of gravity (CoG) and moment of inertia (MoI) about all three axes) of the BepiColombo Mercury Transfer Module (MTM), the component of the composite spacecraft that will provide solar-electric propulsion for the journey to Mercury, have been measured at ESA's European Space Research and Technology Centre (ESTEC) in Noordwijk, the Netherlands.

The mass properties of the MTM were measured using similar techniques to those that were employed for the Mercury Planetary Orbiter (MPO) and the Mercury Composite Spacecraft (MCS). (See journal entries #06 and #07 for further details.)

MTM testing
The tests were again performed in the 'Hydra' cleanroom at the ESTEC Test Centre; the MTM assembly was installed on the WM50/6 test system for lateral CoG measurements, and on the M80/MPMA test system for longitudinal CoG and MoIs determination.

The WM50/6 was used to measure the position of the spacecraft CoG along the lateral (horizontal, in this configuration) axes. The M80/MPMA was used to determine the position of the spacecraft CoG along its longitudinal axis and the Products of Inertia (PoI) about all axes.

BepiColombo is Europe's first mission to Mercury. It is scheduled to launch in August 2015 and arrive at Mercury in January 2022.

It will endure temperatures in excess of 350C and gather data during a one-year nominal mission, with a possible one-year extension. The mission comprises two spacecraft: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO).

During the journey to Mercury, the MMO will be shielded from the Sun by the Magnetospheric Orbiter Sunshield and Interface Structure (MOSIF), which also provides the interface between the MMO and the MPO.

The fourth component of the composite spacecraft stack is the Mercury Transfer Module (MTM), whose primary task is to provide solar-electric propulsion for the journey to Mercury.

]]> Wed, 12 JUN 2013 00:35:24 AEST Subscribe to our daily selection of space, military, environment and energy newsletters responseText http://visitor.constantcontact.com/manage/optin/ea?v=0016gbbKsaiGSpQFojVO8ZoHw%3D%3D