Posted on by Fraser Cain

NASA’s Robonaut Can Move Around Now

Human-like hands, fingers and even television camera eyes have been hallmarks of NASA’s Robonaut, but recent work seeks to give the nimble robot legs, or at least a leg, and even wheels.

Robonaut took its first steps recently during tests at the Johnson Space Center in Houston, using a single “space leg” to move around the outside of a simulated Space Station. Other recent tests put the humanoid robot on wheels, a Segway scooter to be exact, and let it take to the road.

In either configuration, Robonaut?s head, torso, mechanical arms and hands maintain their ability to use the same space tools as humans. In the tests using its “space leg,” Robonaut commuted like a futuristic construction worker hand-over-hand outside a mock spacecraft. Aboard the gryo-stabilized wheels, it glided from one test station to another as its descendants might someday on the surface of the Moon or Mars.

Tests with the leg confirmed that Robonaut could climb around the outside of a spacecraft using handholds and plant its foot at a work site to make repairs or install parts. NASA?s goal is to build robots that could ?live? on the outside of spacecraft, ready for routine maintenance or emergencies. Humans inside the spacecraft would operate Robonaut with wireless controls.

The wheeled tests provided initial proof of concept for planetary Centaurs that merge humanoid robots with rovers. Those tests put Robonaut through its paces while mounted on a Segway Robotic Mobility Platform. They showed that a single teleoperator could simultaneously control both the robot?s mobility and dexterity with a wireless control system.

The climbing tests were a significant step in Robonaut?s development, proving the system?s capability for climbing, stabilizing and handling extravehicular activity (EVA) tools and interfaces in the space environment. The test featured a battery-powered, wireless Robonaut system mounted to an air-bearing sled, floating on a cushion of air, to eliminate friction and emulate the sensations experienced by astronauts working in zero gravity. Robonaut climbed using EVA handrails and plugged its stabilizing ?space leg? into a standard space station WIF (Worksite Interface Fixture) socket, while its operators drove Robonaut?s multiple limbs using innovative new telepresence controls.

?This test proved Robonaut can be operated wirelessly using an interchangeable base for different stabilization and locomotion systems — and it did it in a frictionless, space-like environment,” said Test Conductor Dr. Robert Ambrose of JSC?s Automation, Robotics and Simulation Division. ?These are all key capabilities needed for the development of future ?EVA squads? that leverage the combined talents of humans and robots to make vast improvements in spacewalk productivity.?

The Robonaut Project, which Ambrose leads, is a collaborative effort with the Defense Advanced Research Projects Agency (DARPA), and has been under development at JSC for several years. There are two Robonauts, each with highly dexterous hands that can work with the same tools humans use. Operators remotely control movements of the Robonauts? heads, limbs, hands and twin cameras through a combination of virtual-reality interfaces and verbal commands, relayed either through dedicated cabling or wireless systems.

In order to move about in a zero-gravity environment, a robot must be able to climb by itself, using gaits that smoothly manage its momentum and that minimize contact forces while providing for safety in the event of an emergency. To access worksites aboard the International Space Station and future spacecraft, robots must interact with spacewalking aids designed for humans including tethers, handrails and work anchors.

?The tests were very successful,? Ambrose said. ?The Robonaut team learned which climbing maneuvers are more feasible than others, and tested automated software safety reactions using the robot?s built-in force sensors. We also identified new opportunities for using these sensors in semi-automatic modes that will help operators across short (1-10 second) time delays. Our team will continue to tackle these challenges as NASA looks forward to applying human-robotic interaction to the tasks associated with returning to the Moon and going on to Mars.?

Learn more about Robonaut on the Internet at:

robonaut.nasa.gov

Original Source: NASA News Release

Posted on by Fraser Cain

Envisat Sees the Earth Changing in Real Time

Originally developed to pinpoint attacking aircraft during World War Two, today’s advanced radar technology can detect a very different moving target: shifts of the Earth’s crust that occur as slowly as the growth of your fingernails.

Radar data from satellites such as ESA’s Envisat are used to construct ‘interferograms’ that show millimetre-scale land movements. These rainbow-hued images provide scientists with new insights into tectonic motion, and an enhanced ability to calculate hazards arising when this slow motion speeds up, in the form of earthquakes or volcanic activity.

The ten-instrument payload on Envisat includes an Advanced Synthetic Aperture Radar (ASAR) instrument designed to acquire radar images of the Earth’s surface. Part of Envisat’s assigned ‘background mission’ as it orbits the world every 100 minutes is to prioritise ASAR acquisitions over the seismic belts that cover 15% of the land surface.

“By the time Envisat completes its nominal five-year mission we should have a satisfactory amount of images across all the seismic belts,” said Professor Barry Parsons of the Centre for the Observation and Modelling of Earthquakes and Tectonics at Oxford University.

“To detect the fine ground deformation we are interested in, we require repeated radar images of each site. We then combine pairs of images together using a technique called SAR interferometry, or InSAR for short, to show up any change between acquisitions.” (For more information see link: How does interferometry work?)

To accurately measure the slow build up of strain as tectonic plates move against each other along Earth’s seismic belts, multiple interferograms are combined, requiring many individual SAR images.

“The reason for this is to minimise any atmospheric interference, relative to the small crustal deformation signal we are interested in,” added Parsons. “Using data from Envisat’s predecessor ERS, our group has recently measured tectonic movement across western Tibet with an accuracy of a few millimetres per year. The results show that slip rates across the major faults in the region are much smaller than had been previously thought and that the Tibetan plateau deforms like a fluid.”

InSAR can also be used to analyse much more abrupt ground motion: researchers have recently been employing Envisat data to chart ground deformation associated with the extremely active Piton de la Fournaise volcano on R?union Island in the Indian Ocean, and to identify the fault that caused Iran’s Bam earthquake in December 2003.

Finding fault after the Bam disaster
More than 26000 people were killed on 26 December 2003, when a 6.3 Richter scale earthquake devastated the Iranian oasis town of Bam. Its ancient citadel ? designated a World Heritage site ? collapsed into rubble. The Charter on Space and Major Disasters was activated so that spacecraft including Envisat acquired imagery to support international relief efforts.

Following Envisat’s background mission, a pre-earthquake image had been acquired of the Bam vicinity on 3 December 2003, and this was combined with a post-quake image acquired 7 January 2004 ? the earliest re-acquisition date possible due to Envisat’s 35-day global coverage ? to perform InSAR.

“This is the first time that Envisat data has been used to produce an interferogram following a major earthquake,” said Parsons, part of an international team studying the Bam quake including participants from the Geological Survey of Iran and the US Jet Propulsion Laboratory.

The results were surprising, establishing that while Bam lies in a seismic belt, this particular quake had come from a point no one had expected. Iran is like the filling in a geological sandwich as the Arabian plate advances into Eurasia, and so many seismic faults occur within its territory. Most notably, the Gowk fault located west of Bam has had several large quakes take place on it during the last two decades.

However the Envisat interferogram showed the Bam quake had resulted from the rupture of a previously undetected fault that extends under the southern part of town, its existence missed by ground surveys. The fault showed up as a distinct band of discontinuity in the interferogram, with motion either side of it ranging from around five up to as high as 30 centimetres.

As well as highlighting such surface changes, InSAR results can be used to indirectly peer beneath the ground, with software models calculating what geological occurrences fit the surface events. With Bam they found a slip exceeding two metres had taken place at a mean depth of 5.5 kilometres, along a distinct type of fault.

Coming around again
The more precisely a spacecraft’s position can be controlled, the smaller the InSAR image baseline – the spatial distance between initial and follow-up image acquisitions – and the better the quality of the final interferogram. During Envisat’s initial Bam revisit the baseline was large enough that ERS digital elevation data was needed to subtract topographic effects caused by a shifted view angle.

However for its subsequent revisit, 35 days later, the steering of the spacecraft was so precise that no topographic compensation was required, representing a formidable operational achievement for Envisat.

“Our Flight Dynamics team have computed an accuracy of 93 cm using precise orbit determination results from DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) and laser ranging observations,” stated Envisat Spacecraft Manager Andreas Rudolph.

“Special orbit manoeuvres were required to achieve this accuracy, along with hard work from teams at the European Space Operations Centre (ESOC) here in Germany and the European Space Research Institute (ESRIN) in Italy ? not to mention a bit of luck!”

Surveying an active volcano
Radar interferometry is used to study earthquakes as well as volcanoes – Envisat has been gathering data on one extremely lively example of the latter.

Standing 2631 metres above the Indian Ocean, the Piton de la Fournaise volcano is not situated along seismic belts or the associated ‘Ring of Fire’ but ? like Hawaii on the other side of the planet ? it is sited above a magma ‘hotspot’ in the Earth’s mantle.

The Institut de Physique du Globe de Paris (IPGP) operates an in-situ Volcano Observatory to monitor eruptions and associated activity.

“We have been observing this basaltic volcano for the last 25 years ? it is one of the most active volcanoes in the world,” commented Pierre Briole of IPGP. “In the last six years there have been 13 eruptions, with an average duration of one month. Between 1992 and 1998 was a quiet time, while eight eruptions occurred between 1984 and 1992.”

Deep subterranean processes drive surface volcanic activity ? lava fissures and eruptions occur because of lava channels or ‘dikes’ that extend up from high pressure magma chambers. Ground deformation either up or down in the vicinity of a volcano provides insights into what is taking place underground, but until recently the amount of ground points that could be measured was very limited.

“Back in the time of ground-based geodetic instruments it took several weeks to measure the coordinates of perhaps 20 points, to an accuracy of about one centimetre,” remembered Briole. “Then in the early 1990s came the Global Positioning System (GPS). Using GPS we could increase the number of points measured tenfold during a weeklong campaign, down to half-centimetre accuracy. But the ground deformation caused by an eruption is typically extremely localised in space, and these 200 points are spread out across the volcano’s area.”

It took another space-based technology to improve on GPS: interferograms of Piton de la Fournaise, based on more than 60 Envisat images acquired during the last year. IPGP is part of a team making use of the data that also includes participants from Blaise Pascal (Clermont-Ferrand II) and R?union Universities.

“We are lucky with Piton de la Fournaise, because its remote location in the middle of the ocean means there are no clashes with other potential Envisat targets, and so we get more acquisitions than most of the other users of ASAR imagery,” Briole added. “InSAR from Envisat has proved an extremely powerful tool for us, because it provides a very high density of information across the entire volcano.

“With new eruptions taking place so often our ground campaigns could not keep pace but interferometry gives us data on each eruption. And while the volcano is very difficult place to operate in ? often with poor visibility from the weather and a very steep eastern flank ? all parts of the volcano down to vegetation line are accessible with InSAR.”

InSAR reveals a pattern of ground inflation in the months preceding a new eruption, as pressure in the magma chamber increases. Following an eruption the pressure abates and deflation occurs.

Also revealed are localised deformations that occur as magma dikes propagate and reach the surface. The extent of the deformation associated with a new fissure indicates the depth at which it originates ? the wider the inflation, the deeper down the dike has come from.

InSAR volcanic monitoring was first established using ERS data, producing interferograms showing Italy’s highly-active Mount Etna appearing to ‘breathe’ between eruptions. And interferogram surveys of apparently extinct volcanoes along remote parts of the Andes have shown ground motion indicating some are in fact still active.

“There are plenty of interesting lines of enquiry using this technique, including the question of whether it is possible to predict when a volcano is going to erupt, and – with seismic faults often occurring near volcanoes – the question of whether seismic activity and volcanic eruptions are linked,” Briole added.

“For now our team are interested in characterising Piton de la Fournaise as accurately as we can, to perfect techniques we can later apply to volcanoes elsewhere and if possible to increase the number of acquisitions so as to demonstrate that InSAR monitoring of volcanoes has operational potential, providing early warning for civil protection authorities.”

Original Source: ESA News Release

Posted on by Fraser Cain

Detailed Picture of Stormy Saturn

Details in Saturn?s southern polar region highlight the often turbulent nature of the interfaces that separate the cloud bands on this swirling gaseous globe.

The image was taken with the narrow angle camera on July 13, 2004, from a distance of 5.1 million kilometers (3.2 million miles) from Saturn through a filter sensitive to wavelengths of infrared light centered at 889 nanometers. The image scale is 30 kilometers (19 miles) per pixel. Contrast has been enhanced slightly to aid visibility.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Original Source: CICLOPS News Release

Posted on by Fraser Cain

Dwarf Galaxies Have Been Through a Lot

Astronomers have shown for the first time that even the smallest galaxies in the Universe have complex structures that indicate a complex history. Using the Subaru Telescope, a team of astronomers from the National Astronomical Observatory of Japan, the Institute of Physics in Lithuania, the University of Durham, Paris Observatory, Kyoto University, Gunma Astronomical Observatory, and the University of Tokyo have discovered an extended halo of stars with a sharp cutoff in the dwarf irregular galaxy Leo A, a member of the Local Group of galaxies that includes the Milky Way. The discovery challenges current scenarios of galaxy formation by showing that instead of being the preservers of pristine building blocks that combined to form larger galaxies, dwarf irregular galaxies have their own history of build-up.

Understanding galaxy formation and evolution on time scales comparable to the age of the Universe is one of astronomy’s greatest challenges. In the scenarios of standard cosmology (Note 1), galaxies are built up via hierarchical merging: small primordial density fluctuations in the smooth distribution of matter in the early Universe grow and combine to form larger structures like the Milky Way. The most numerous type of galaxies in the universe — dwarf irregular galaxies (Note 2) — are supposed to preserve their properties unchanged over billions of years and represent pristine primeval building blocks. This is one reason why astronomers have recently been studying dwarf irregular galaxies with great interest.

The team led by Professors Nobuo Arimoto (National Astronomical Observatory of Japan) and Vladas Vansevicius (Institute of Physics, Lithuania) has studied Leo A — an isolated and extremely gas rich dwarf irregular galaxy with only 0.01% of the mass of the Milky Way and a low fraction chemical elements produced by earlier generations of stars. These characteristics suggest that this galaxy has been evolving without significant interaction with other galaxies. This galaxy has been believed to have quite a simple structure, in contrast to large disk galaxies like the Milky Way. However, this view needs to be changed due to deep imaging of the outer regions of this galaxy with the Subaru Telescope.

Prior to these observations, Leo A was already known to have a large angular size (7′ x 5′; Note 3) and Subaru Telescope equipped with its Prime Focus Camera (Suprime-Cam) was an ideal instrument to study the stars at the galaxy’s outer limits (Fig. 1). A single exposure with Suprime-Cam covers a field of view of 34′ x 27′ (pixel size 0”.2 x 0”.2) with high sensitivity. The team acquired optical images of the dwarf irregular galaxy Leo A with three broad band filters in November 2001. In order to trace the entire extent of the old stars in Leo A, the team employed red giant branch (RGB) stars which are evolved low-mass stars with very high luminosity and are expected to represent well the extended structures of galaxies. They investigated inside an ellipse of semi-major axis a = 12′ which fully covers the galaxy, and detected 1394 RGB stars distributed symmetrically and smoothly within this field.

Fig. 2 shows the radial profile of the surface number density of the red giant stars. The team found significantly larger disk structure (with a semi-major axis of 5.5′) than previously known (3.5′). Moreover, the deep observations permitted the discovery of a new stellar component in dwarf irregular galaxies, which the team calls a ?halo? (5.5′-7.5′), which has a less steep slope in the number density of RGB stars. The halo component ends at 8′ from the center of the galaxy with a sharp cutoff in the RGB star distribution. The existence of such a halo structure in dwarf irregular galaxies had been unconfirmed before these observations.

The size of Leo A revealed by these new observations is twice as large as its previously accepted size, suggesting that even in the nearby universe we see galaxies only as ?tips of icebergs” that are actually a few times more extended.

The newly discovered halo with a sharp stellar cutoff and the disk of the dwarf irregular galaxy Leo A closely resembles the structure as well as stellar and gaseous content found in large full-fledged disk galaxies like the Milky Way. The complicated structure of large massive galaxies has been believed to be a result of the merging of less massive galaxies like dwarf irregular ones. However, this study clearly reveals that the dwarf irregular galaxy Leo A already has disk and halo components, and suggests complex build-up histories for even very low mass galaxies like Leo A, which are supposed to form directly from the primordial density fluctuations in the early universe (Note 1), and challenges contemporary understanding of galaxy evolution. Professors N. Arimoto and V. Vansevicius believe Leo A is a ?Rosetta stone? (Note 4) for understanding the process of galaxy formation and evolution.

The scientific paper on this research has been accepted for publication in the August 20, 2004, Astrophysical Journal Letters (Volume 611, Number 2, L93).

Original Source: Subaru News Release

Posted on by Fraser Cain

Perseids Will Peak on August 11

The Perseid meteor shower, an annual celestial event beloved by millions of skywatchers around the world, returns to the night sky this coming week.

Sky & Telescope magazine predicts that the Perseid shower will reach its peak late Wednesday night and early Thursday morning, August 11?12. The rate of activity should pick up steam after midnight until the first light of dawn. North America, especially the West and Hawaii, is optimally positioned to catch the best of the shower.

An observer under a dark sky might typically see more than 60 Perseids per hour between midnight and dawn. Since the waning crescent Moon will be only three days from new at the time of shower maximum, posing minimal interference with the view, this is an opportune year for watching them.

You’ll need no equipment but your eyes. The darker your sky, the better ? any artificial light pollution in your sky will reduce the number of meteors that are visible. But even if you live in an urban or suburban area, you have a good chance of seeing at least some meteors. Find a dark spot with a wide-open view of the sky. Bring a reclining lawn chair, insect repellent, and blankets or a sleeping bag; clear August nights can get surprisingly chilly.

“Go out after about 11 p.m. or so, lie back, and watch the stars,” says Sky & Telescope senior editor Alan MacRobert. “Relax, be patient, and let your eyes adapt to the dark. With a little luck you’ll see a ‘shooting star’ every couple of minutes on average.”

Perseids can appear anywhere and everywhere in the sky. So the best direction to watch is wherever your sky is darkest, probably straight up. Faint Perseids appear as tiny, quick streaks. Occasional brighter ones may sail across the heavens for several seconds and leave a brief train of glowing smoke.

If you trace each meteor’s direction of flight backward far enough across the sky, you’ll find that your imaginary line crosses a spot in the constellation Perseus, near Cassiopeia. This is the shower’s radiant, the perspective point from which all the Perseids would appear to come if you could see them approaching from interplanetary space. The radiant is low in the north-northeast before midnight and rises higher in the northeast during the early-morning hours.

Don’t give up if it’s cloudy Wednesday night. The Perseid shower lasts for about two weeks, with good rates in the predawn hours of August 10th through 15th. This year the ever-thinning Moon becomes less of a problem with each passing night. Far fewer meteors will appear before midnight, even on the night of the shower’s maximum, because the radiant is then quite low in the sky. The radiant is always low or below the horizon for Southern Hemisphere countries like Australia, New Zealand, and South Africa, where few, if any, Perseids can be seen.

The Perseid meteoroids are tiny, sand- to pea-size bits of rocky debris that were shed long ago by Comet Swift-Tuttle. This comet, like others, is slowly disintegrating as it orbits the Sun. Over the centuries, its crumbly remains have spread all along its 130-year orbit to form a sparse “river of rubble” hundreds of millions of miles long.

Earth’s own path around the Sun carries us through this stream of particles every mid-August. The particles, or meteoroids, are traveling 37 miles per second with respect to Earth at the place where we encounter them. So when one of them strikes the upper atmosphere (about 50 to 80 miles up), it creates a quick, white-hot streak of superheated air.

For several years in the early 1990s the Perseids performed spectacularly, flaring with outbursts of up to hundreds of meteors per hour. The particles responsible for these outbursts were probably shed during Comet Swift-Tuttle’s swing by the Sun in 1862.

Astronomers Esko Lyytinen of Finland and Tom Van Flandern of Washington, DC, have alerted skygazers to the possibility that this “extra” Perseid peak could make a comeback in 2004. They predict that this year, the rubble trail released in 1862 will pass just 200,000 kilometers (125,000 miles)) inside Earth’s orbit on August 11th, just as observing conditions become optimal for meteor watchers in Eastern Europe and eastern North Africa eastward to central Russia, India, and western China.

Will the Perseids “storm” in 2004? There’s only one way to find out: Get outside and watch the show!

More about the Perseid meteors ? and how to watch and photograph them ? appears in the August 2004 issue of Sky & Telescope magazine and online in the articles listed at the end of this press release.

Original Source: Sky and Telescope News Release

Posted on by Fraser Cain

NASA Extends TRMM Mission through 2004

NASA will extend operation of the Tropical Rainfall Measuring Mission (TRMM) through the end of 2004, in light of a recent request from the National Oceanic and Atmospheric Administration (NOAA). The extension, to be undertaken jointly with NASA’s TRMM partner, the Japan Aerospace Exploration Agency (JAXA), will provide data during another storm season in the U.S. and Asia.

TRMM has yielded significant scientific research data over the last seven years to users around the globe. In addition, TRMM data has aided NOAA, other government agencies, and other users in their operational work of monitoring and predicting rainfall and storms, as well as in storm research. Launched in 1997, TRMM was originally designed as a three-year research mission. Following four years of extending TRMM, NASA and JAXA recently announced a decision to decommission TRMM, and proceed with a safe, controlled deorbit. Options for safe re-entry become increasingly limited the longer TRMM is operated, as it is already more than 3 years beyond design life.

“NASA is committed to working with our partner agencies to help them carry out their mission. We have decided to extend TRMM through this year’s hurricane season in our effort to aid NOAA in capturing another full season of storm data,” said Dr. Ghassem Asrar, Deputy Associate Administrator of NASA’s Science Mission Directorate. “The United States is a leader in Earth remote sensing, and NASA is proud of our role in building that leadership. Our work in partnership with NOAA and international partners such as JAXA is an important part of the world’s scientific research on global precipitation and weather. TRMM has been a valuable part of that legacy and we look to our follow-on missions to continue to reap great public benefit,” he added.

TRMM is the first satellite to measure rainfall over the global tropics, allowing scientists to study the transfer of water and energy among the global atmosphere and ocean surface that form the faster portions of the Earth’s climate system. Because TRMM’s radar enables it to “see through” clouds, it allows weather researchers to make the equivalent of a CAT-scan of hurricanes and helps weather forecasters to use TRMM data to improve prediction of severe storms.

“TRMM has proven helpful in complementing the other satellite data used by NOAA’s National Weather Service in its operations,” said Retired Air Force Brig. Gen. David L. Johnson, Director of NOAA’s National Weather Service.

JAXA welcomes and supports the decision to extend TRMM. The extension will be of benefit to the worldwide science and research communities. NASA and JAXA look forward to continuing their close collaboration beyond TRMM through establishment of a new advanced capability for the measurement of precipitation globally with the Global Precipitation Measurement Mission (GPM). GPM will use an extensive ground validation network to further improve the accuracy of its measurements compared to those made by TRMM.

NASA and NOAA have asked the National Academy of Sciences to convene a workshop next month to advise NASA and NOAA on the best use of TRMM’s remaining spacecraft life; the overall risks and benefits of the TRMM mission extension options; the advisability of transfer of operational responsibility for TRMM to NOAA; any requirement for a follow-on operational satellite to provide comparable TRMM data; and optimal use of GPM, a follow-on research spacecraft to TRMM, planned for launch by the end of the decade.

“It’s important to note that we are able to extend TRMM for this brief period and are vigilant in maintaining our requirement for a safe, controlled re-entry and deorbit of the spacecraft,” said Asrar. “We also welcome the opportunity to receive advice from the National Academy of Sciences next month on the best use of TRMM’s remaining spacecraft life, TRMM re-entry risk, and the best use of our upcoming next-generation research spacecraft, GPM,” he added

NASA and NOAA will work with the National Academy of Sciences to share with the public outcomes from next month’s workshop.

For more information about TRMM on the Internet, visit:

http://trmm.gsfc.nasa.gov/

Original Source: NASA News Release

Posted on by Fraser Cain

Outbound View of Saturn After Initial Orbit

A frigid ball of gas in the blackness of space, Cassini?s new home appears cool and serene in this natural color image.

The spacecraft obtained this view as it sped outward from the planet on its initial orbit. At left, Saturn?s shadow stretches almost completely across the rings, while at right the planet?s illuminated face appears to gaze down at the far-off Sun.

Images taken through blue, green and red filters with the wide angle camera were combined to create this natural color view. The images were taken on July 17, 2004, from a distance of about 5.8 million kilometers (3.6 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 93 degrees. The image scale is 346 kilometers (215 miles) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Posted on by Fraser Cain

Cassini Sees Lightning on Saturn

The Cassini spacecraft, which began its tour of the Saturn system just over a month ago, has detected lightning and a new radiation belt at Saturn, and a glow around the planet’s largest moon, Titan.

The spacecraft’s radio and plasma wave science instrument detected radio waves generated by lightning. “We are detecting the same crackle and pop one hears when listening to an AM radio broadcast during a thunderstorm,” said Dr. Bill Kurth, deputy principal investigator on the radio and plasma wave instrument, University of Iowa, Iowa City. “These storms are dramatically different than those observed 20 years ago.”

Cassini finds radio bursts from this lightning are highly episodic. There are large variations in the occurrence of lightning from day to day, sometimes with little or no lightning, suggesting a number of different, possibly short-lived storms at middle to high latitudes. Voyager observed lightning from an extended storm system at low latitudes, which lasted for months and appeared highly regular from one day to the next.

The difference in storm characteristics may be related to very different shadowing conditions in the 1980s than are found now. During the Voyager time period when lightning was first observed, the rings cast a very deep shadow near Saturn’s equator. As a result, the atmosphere in a narrow band was permanently in shadow — making it cold — and located right next to the hottest area in Saturn’s atmosphere. Turbulence between the hot and cold regions could have led to long-lived storms. However, during Cassini’s approach and entry into Saturn’s orbit, it is summer in the southern hemisphere and the ring shadow is distributed widely over a large portion of the northern hemisphere, so the hottest and coldest regions are far apart.

A major finding of the magnetospheric imaging instrument is the discovery of a new radiation belt just above Saturn’s cloud tops, up to the inner edge of the D-ring. This is the first time that a new Saturnian radiation belt has been discovered with remote sensing.

This new radiation belt extends around the planet. It was detected by the emission of fast neutral atoms created as its magnetically trapped ions interact with gas clouds located planetward of the D-ring, the innermost of Saturn’s rings. With this discovery, the radiation belts are shown to extend far closer to the planet than previously known.

“This new radiation belt had eluded detection by any of the spacecraft that previously visited Saturn. With its discovery we have seen something that we did not expect, that radiation belt particles can ‘hop’ over obstructions like Saturn’s rings, without being absorbed by the rings in the process,” said Dr. Donald G. Mitchell, instrument scientist for the magnetospheric imaging instrument at the Johns Hopkins University Applied Physics Laboratory, Laurel, Md.

Saturn’s largest moon, Titan, is also shining for attention. Cassini’s visual and infrared mapping spectrometer captured Titan glowing both day and night, powered by emissions from methane and carbon monoxide gases in the moon’s extensive, thick atmosphere.

“Not only is Titan putting on a great light show but it is also teaching us more about its dense atmosphere,” said Dr. Kevin Baines, science team member for the visual and infrared mapping spectrometer at JPL. “What is amazing is that the size of this glow or emission of gases is a sixth the diameter of the planet.”

The Sun-illuminated fluorescent glow of methane throughout Titan’s upper atmosphere ? revealing the atmosphere’s immense thickness and extending more than 700 kilometers (435 miles) above the surface, was expected. However, the nighttime glow, persistently shining over the night side of Titan, initially surprised scientists.

“These images are as if you were seeing Titan through alien eyes. Titan glows throughout the near-infrared spectrum. If you were an alien it would be hard to get a good night’s sleep on Titan because the light would always be on,” said Baines.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. JPL designed, developed and assembled the Cassini orbiter.

For the latest images and more information about the Cassini- Huygens mission, visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Proton Launches Amazonas Satellite

A Proton rocket launched by International Launch Services (ILS) successfully carried the Amazonas satellite into orbit today.

The 191-foot-tall (58.2-meters) vehicle lifted off at 4:32 a.m. from Baikonur (6:32 p.m. EDT Wednesday, 22:32 GMT Wednesday). The rocket?s Breeze M upper stage placed the satellite into a transfer orbit 9 hours and 11 minutes later.

The launch vehicle was built by Khrunichev State Research and Production Space Center of Moscow, a partner in the ILS joint venture along with Lockheed Martin Corp. [NYSE:LMT]. This was the third Proton launch of the year for ILS, and the seventh mission overall for the company in 2004.

The satellite was built for Hispasat of Spain, and will be used by its subsidiaries Hispamar of Brazil and Hispasat Canarias to provide a multitude of communications services at both C- and Ku-band on both sides of the Atlantic Ocean. When it reaches its operating position of 61 degrees West longitude, the Amazonas satellite will be the largest in the Hispasat fleet. The high-power satellite is a Eurostar E3000 model built by EADS Astrium of Europe, the third E3000 spacecraft launched by ILS this year.

?We thank Hispasat for again selecting an ILS vehicle,? said ILS President Mark Albrecht. ?We have demonstrated that Hispasat can rely on us for a good launch, whether they choose Proton, or whether they choose Atlas as they have twice before.?

Albrecht added that the Proton vehicle has now completed five missions this year, three for ILS and two for the Russian government. ?We call this the workhorse of the Russian fleet, because it flies so often and so reliably. Everyone from start-up businesses to telecommunications giants to participants in the International Space Station have put their trust in Proton,? he said. ?ILS is proud to market this vehicle for commercial satellite launches.?

“This is a major milestone for EADS Astrium, with Amazonas being the third Eurostar E3000 version satellite to be launched this year by a Proton Breeze M launcher from ILS,” said Antoine Bouvier, CEO of EADS Astrium. ?Amazonas is the most powerful satellite ordered by Hispasat. The satellite was delivered in time, which was very important. This satellite is equipped with a new lithium-ion battery offering higher efficiency. All our teams in Europe were mobilized to make this event a success.?

ILS has established itself as the indisputable launch services leader by offering the industry’s two best launch systems: Proton and the Lockheed Martin-built Atlas. With a remarkable launch rate of 65 missions since 2000, the Atlas and Proton launch vehicles have consistently demonstrated the reliability and flexibility that have made them the vehicles of choice. Since the beginning of 2003, ILS has signed more new commercial contracts than all its competitors combined. ILS was formed in 1995, and is based in McLean, Va., a suburb of Washington, D.C.

Original Source: ILS News Release

Posted on by Fraser Cain

da Vinci Project Announces X Prize Attempt

The Canadian da Vinci Project Team has notified the ANSARI X PRIZE of its intention to launch its rocket on October 2nd, 2004, marking its official entry in the international, commercially-funded space race competition.

The da Vinci Project, which unveiled its rocket Wild Fire today, joins one American team — in a field of 26 — to announce its launch date. “With two ANSARI X PRIZE teams launching within days of each other for the $10 million prize (U.S.), we truly have a remarkable race for space,” said Dr. Peter H. Diamandis, Chairman and Founder of the X PRIZE Foundation. The recipient of the $10 million prize will be the first team to travel safely to space twice within a two-week period on a privately funded, re-useable spacecraft.

Brian Feeney, who plans to pilot Wild Fire approximately 85 kilometers into suborbital space, said the team is finalizing construction of the rocket as well as logistical details related to the event, which will be held in Kindersley, Saskatchewan.

“We’re very close to achieving our mission, thanks to the organizations and individuals that understand the significance of this race,” said Feeney. “The da Vinci Project is on the cusp of a new era of space travel for humankind. Our team is proof positive that ingenuity and innovation can overcome the impossible.”

In addition, Feeney announced a new sponsor to finance the project. Golden Palace.Com, the world’s largest online casino, has signed on as the title sponsor. The Golden Palace.Com Space Program — Powered By The da Vinci Project — is poised to make history.

According to sources at the casino, GoldenPalace.com is excited and very proud to be a part of the historic flight of the Wild Fire. In the continuing pursuit for innovative ideas for exposure, Golden Palace sources believes the ANSARI X Prize competition provides the advertising exposure as well as the added incentive of a history-making event that will eventually serve to benefit all humankind.

The da Vinci Project, which Feeney describes as the largest volunteer technology project in Canada, has achieved several critical milestones since officially entering the competition in 1996. These milestones have included the filing of necessary papers to Canadian government for launch approval; securing the site for launch; the testing of engine components; testing the design and securing a wide range of sponsors including Sun Microsystems of Canada, Blake Cassels Graydon, ANSYS, Hinz Automation and Kindersley Transport.

“The da Vinci Project is emblematic of the spirit of the ANSARI X PRIZE,” said Diamandis. “It brings together many of the best and brightest to break down preconceived notions on space travel and prove that we are no longer bound to one planet.”

The X PRIZE Foundation is working with the Federation Aeronautique Internationale (FAI), the international body responsible for all aviation and space world records, to ensure that the ANSARI X PRIZE winner will also receive official international recognition for his achievement. In addition to duration, altitude and distance, the FAI has introduced new world record categories for ‘minimum time between two consecutive sub-orbital flights in a reusable vehicle’ and ‘number of persons carried in sub-orbital flight’.

Original Source: da Vinci Project News Release