welcome to the astronomy news world

Sunday, August 22, 2004

Are we alone?

The search begins...
Are we alone?
For centuries, human beings have pondered this question.

Artist's concept of an extrasolar planetary system.Artist's concept of an extrasolar planetary system.

Medieval scholars speculated that other worlds must exist and that some would harbor other forms of life.
In our time, advances in science and technology have brought us to the threshold of finding an answer to this timeless question.
The recent discovery of numerous planets around stars other than the Sun confirms that our solar system is not unique. Indeed, these "extrasolar planets" appear to be common in our galactic neighborhood.
The extrasolar planets we have discovered thus far are giants, like Jupiter and Saturn. They are unlikely to support life as we know it. But some of these planetary systems might also contain smaller, terrestrial planets like Mars and Earth.
Over the next 15 years, NASA is embarking on a bold series of missions to find and characterize new worlds. These will be the most sensitive instruments ever built, capable of reaching beyond the bounds of our own solar system.

Artist's concept of Terrestrial Planet FinderArtist's concept of Terrestrial Planet Finder

The Keck Interferometer will combine the light of the world's largest optical telescopes, extending our vision to new distances.
Using a technique known as interferometry, the Keck will study dust clouds around stars where planets may be forming. It may also provide the first direct images of giant planets outside our solar system.
The Space Interferometry Mission will measure the distances and positions of stars with unprecedented accuracy. SIM's precision will allow us to detect evidence of planets just slightly larger than Earth.
Finally, the Terrestrial Planet Finder will build upon the legacy of all that have gone before it. With an imaging power 100 times greater than the Hubble Space Telescope, Terrestrial Planet Finder will send back the first photographs of nearby planetary systems.
Artist's concept of an Earth-like planetArtist's concept of an Earth-like planet

We will analyze the atmospheres of these distant worlds, looking for carbon dioxide, water and ozone. The substantial presence of all three gasses would suggest that life is present.

Such a discovery would at last provide convincing evidence that we are not alone.
We will have found another Earth.

Index From NASA:

http://planetquest.jpl.nasa.gov/overview/overview_index.html

Sayyed Mohammad Reza Naserian

Friday, August 20, 2004

NASA Mission Returns With a Piece of the Sun


In a dramatic ending that marks a beginning in scientific research, NASA's Genesis spacecraft is set to swing by Earth and jettison a sample return capsule filled with particles of the Sun that may ultimately tell us more about the genesis of our solar system.
"The Genesis mission -- to capture a piece of the Sun and return it to Earth -- is truly in the NASA spirit: a bold, inspiring mission that makes a fundamental contribution to scientific knowledge," said Steven Brody, NASA's program executive for the Genesis mission, NASA Headquarters, Washington.
On September 8, 2004, the drama will unfold over the skies of central Utah when the spacecraft's sample return capsule will be snagged in midair by helicopter. The rendezvous will occur at the Air Force's Utah Test and Training Range, southwest of Salt Lake City.
"What a prize Genesis will be," said Genesis Principal Investigator Dr. Don Burnett of the California Institute of Technology, Pasadena, Calif. "Our spacecraft has logged almost 27 months far beyond the moon's orbit, collecting atoms from the Sun. With it, we should be able to say what the Sun is composed of, at a level of precision for planetary science purposes that has never been seen before."
The prizes Burnett and company are waiting for are hexagonal wafers of pure silicon, gold, sapphire, diamond and other materials that have served as a celestial prison for their samples of solar wind particles. These wafers have weathered 26-plus months in deep space and are now safely stowed in the return capsule. If the capsule were to descend all the way to the ground, some might fracture or break away from their mountings; hence, the midair retrieval by helicopter, with crew members including some who have performed helicopter stunt work for Hollywood.
"These guys fly in some of Hollywood's biggest movies," said Don Sweetnam, Genesis project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "But this time, the Genesis capsule will be the star." The Genesis capsule -- carrying the agency's first sample return since the final Apollo lunar mission in 1972, and the first material collected beyond the Moon -- will enter Earth's atmosphere at 9:55 am Mountain Time. Two minutes and seven seconds after atmospheric entry, while still flying supersonically, the capsule will deploy a drogue parachute at 33 kilometers (108,000 feet) altitude. Six minutes after that, the main parachute, a parafoil, will deploy 6.1 kilometers (20,000 feet) up. Waiting below will be two helicopters and their flight crews looking for their chance to grab a piece of the Sun.
"Each helicopter will carry a crew of three," said Roy Haggard, chief executive officer of Vertigo Inc. and director of flight operations for the lead helicopter. "The lead helicopter will deploy an eighteen-and-a-half foot long pole with what you could best describe as an oversized, Space-Age fishing hook on its end. When we make the approach we want the helicopter skids to be about eight feet above the top of the parafoil. If for some reason the capture is not successful, the second helicopter is 1,000 feet behind us and setting up for its approach. We estimate we will have five opportunities to achieve capture."
The helicopter that does achieve capture will carry the sample canister to a clean room at the Michael Army Air Field at the U.S. Army Dugway Proving Ground, where scientists await their cosmic prize. The samples will then be moved to a special laboratory at NASA's Johnson Space Center, Houston, where they will be preserved and studied by scientists for many years to come.
"I understand much of the interest is in how we retrieve Genesis," added Burnett. "But to me the excitement really begins when scientists from around the world get hold of those samples for their research. That will be something."
JPL, a division of the California Institute of Technology, manages the Genesis mission for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, developed and operates the spacecraft. Los Alamos National Laboratory and NASA's Johnson Space Center contributed to Genesis payload development, and the Johnson Space Center will curate the sample and support analysis and sample allocation.
More detailed background on the mission is available at http://jpl.convio.net/site/R?i=owtwJtBoz19O-3BCLCXxIg.. .
-end-

Future

Future Mission Concepts May Become Reality
08.12.04 The murky, auburn tones of the Keyhole Nebula.
NASA is considering nine astrophysics experiments that could pave the way toward future space missions designed to reveal the nature of the universe and how life was formed. The candidates are mission hopefuls for becoming part of NASA's Astronomical Search for Origins Program. Operated by the Jet Propulsion Laboratory in Pasadena, Calif., the Origins Program seeks to answer the basic questions regarding our universe and the origin of life. Selected from a pool of 26 proposals, the concept finalists offer an array of experiments and methods for studying astronomical objects and their chemical composition. Researchers now have eight months to refine their projects to outline mission objectives and possible spacecraft design. Image to right: Scientists want to know more about the soupy mix of free-floating organic compounds that led to life in the universe. Credit: NASA Many of the projects plan to investigate the universe as it exists today, while others will use their technology to peer back in time to examine the cosmic past. One such instrument could be the Hubble Origins Probe. With its powerful sensors and camera, the Hubble Origins Probe concept proposes the construction of a highly-advanced space-based telescope. The Probe would use instruments originally designed for the Hubble Space Telescope to analyze the birth of individual stars, planets and black holes that formed millions of year ago. One a broader scale, the Baryonic Structure Probe intends to detect and map the flow of chemical matter into early galaxies. Understanding the path of these galactic chemical currents would give scientists tremendous insight into the twisting and churning mechanics of the universe. Many scientists believe the universe is expanding outward from a central point and occupying more and more space. The Cosmic Inflation Probe aims to measure the shape of the universe's expansion by locating galaxies that formed early in history. The immediate location of the galaxies would be compared with their beginning position and used to define the shape of their expansion.
The Hubble Space Telescope gliding above the Earth.


Image to left: Deep space research missions like the Hubble Space Telescope have shown us a universe we previously only dreamed existed. Future missions will extend our reach into the cosmos and allow us to discover the principles and mechanisms for the development of galaxies, planets and life. Credit: NASA Focusing on more than just the past, scientists are also devising ways to scan the present cosmos. The Origins Billion Star Survey mission intends to count all of the larger planets in the Milky Way, as well as the stars within 30,000 light years of the Sun. Looking to understand the building blocks of life, the Astrobiology Space InfraRed Explorer observatory will search for organic materials in space and attempt to identify how they enter a planet's environment. Time will tell which designs make it from the drawing board to the launch pad. Whatever the results, individually or collectively, any of one of these missions may show us the universe of yesterday, how it exists today, or where it might be tomorrow.

Charlie Plain
NASA's John F. Kennedy Space Center

Thursday, August 19, 2004

very nice image of the day : i don't know


nasa and athens 2004

nasa withe hubble problems went to help olympic jesus help space world









the picture of day : mars exploration rover"sprit"

sprit on the columbia elvation
the pictur taken from panaromica camera

larger image

Wednesday, August 18, 2004

Astronomy Picture of the Day

2004 August 18

See Explanation.  Clicking on the picture will download
 the highest resolution version available.

Lightning on Earth
Credit & Copyright:
Elizabeth Warner (U. Maryland)

CASSINI PHOTO RELEASE
Posted: August 16, 2004

With eyes sharper than any that have peered at Saturn before, the Cassini spacecraft has uncovered two moons, which may be the smallest bodies so far seen around the ringed planet.
This image shows the tiny 'worldlet,' temporarily dubbed S/2004 S1, as it makes its way around the planet. A white box frames the moon's location in the image. Credit: NASA/JPL/Space Science Institute

The moons are approximately 3 kilometers (2 miles) and 4 kilometers (2.5 miles) across -- smaller than the city of Boulder, Colorado. The moons, located 194,000 kilometers (120,000 miles) and 211,000 kilometers (131,000 miles) from the planet's center, are between the orbits of two other saturnian moons, Mimas and Enceladus. They are provisionally named S/2004 S1 and S/2004 S2. One of them, S/2004 S1, may be an object spotted in a single image taken by NASA's Voyager spacecraft 23 years ago, called at that time S/1981 S14.

"One of our major objectives in returning to Saturn was to survey the entire system for new bodies," said Dr. Carolyn Porco, imaging team leader, Space Science Institute, Boulder, Colo. Porco planned the imaging sequences. "So, it's really gratifying to know that among all the other fantastic discoveries we will make over the next four years, we can now add the confirmation of two new moons, skipping unnoticed around Saturn for billions of years until just now.²

The moons were first seen by Dr. Sebastien Charnoz, a planetary dynamicist working with Dr. Andre Brahic, imaging team member at the University of Paris. "Discovering these faint satellites was an exciting experience, especially the feeling of being the first person to see a new body of our solar system," said Charnoz. "I had looked for such objects for weeks while at my office in Paris, but it was only once on holiday, using my laptop, that my code eventually detected them. This tells me I should take more holidays."

The smallest previously known moons around Saturn are about 20 kilometers (12 miles) across. Scientists expected that moons as small as S/2004 S1 and S/2004 S2 might be found within gaps in the rings and perhaps near the F ring, so they were surprised these small bodies are between two major moons. Small comets careening around the outer solar system would be expected to collide with small moons and break them to bits.



This shows the second new 'worldlet,' temporarily dubbed S/2004 S2. Credit: NASA/JPL/Space Science Institute


The fact that these moons exist where they do might provide limits on the number of small comets in the outer solar system, a quantity essential for understanding the Kuiper Belt of comets beyond Neptune, and the cratering histories of the moons of the giant planets.

"A comet striking an inner moon of Saturn moves many times faster than a speeding bullet," said Dr. Luke Dones, an imaging team member from the Southwest Research Institute in Boulder, Colo. "If small, house-sized comets are common, these moons should have been blown apart many times by cometary impacts during the history of the solar system. The disrupted moon would form a ring, and then most of the material would eventually gather back together into a moon. However, if small comets are rare, as they seem to be in the Jupiter system, the new moons might have survived since the early days of the solar system."

Moons surrounding the giant planets generally are not found where they originally formed because tidal forces from the planet can cause them to drift from their original locations. In drifting, they may sweep through locations where other moons disturb them, making their orbits eccentric or inclined relative to the planet's equator. One of the new moons might have undergone such an evolution.

Upcoming imaging sequences will scour the gaps in Saturn's rings in search of moons believed to be there. Meanwhile, Cassini scientists are eager to get a closer look, if at all possible, at their new finds. Porco said, "We are at this very moment looking to see what the best times are for retargeting. Hopefully, we haven't seen the last of them."

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. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

How old is the Milky Way?

EUROPEAN SOUTHERN OBSERVATORY NEWS RELEASE
Posted: August 17, 2004

Observations by an international team of astronomers with the UVES spectrometer on ESO's Very Large Telescope at the Paranal Observatory have thrown new light on the earliest epoch of the Milky Way galaxy.


This ESO image shows the globular cluster NGC 6397, located at a distance of approx. 7,200 light-years in the southern constellation Ara. It has undergone a "core collapse" and the central area is very dense. Credit: ESO

The first-ever measurement of the Beryllium content in two stars in a globular cluster (NGC 6397) - pushing current astronomical technology towards the limit - has made it possible to study the early phase between the formation of the first generation of stars in the Milky Way and that of this stellar cluster. This time interval was found to amount to 200 - 300 million years.

The age of the stars in NGC 6397, as determined by means of stellar evolution models, is 13,400 +/- 800 million years. Adding the two time intervals gives the age of the Milky Way, 13,600 +/- 800 million years.

The currently best estimate of the age of the Universe, as deduced, e.g., from measurements of the Cosmic Microwave Background, is 13,700 million years. The new observations thus indicate that the first generation of stars in the Milky Way galaxy formed soon after the end of the ~200 million-year long "Dark Ages" that succeeded the Big Bang.

The age of the Milky Way

How old is the Milky Way ? When did the first stars in our galaxy ignite ?

A proper understanding of the formation and evolution of the Milky Way system is crucial for our knowledge of the Universe. Nevertheless, the related observations are among the most difficult ones, even with the most powerful telescopes available, as they involve a detailed study of old, remote and mostly faint celestial objects.

Globular clusters and the ages of stars

Modern astrophysics is capable of measuring the ages of certain stars, that is the time elapsed since they were formed by condensation in huge interstellar clouds of gas and dust. Some stars are very "young" in astronomical terms, just a few million years old like those in the nearby Orion Nebula. The Sun and its planetary system was formed about 4,560 million years ago, but many other stars formed much earlier. Some of the oldest stars in the Milky Way are found in large stellar clusters, in particular in "globular clusters", so called because of their spheroidal shape.

Stars belonging to a globular cluster were born together, from the same cloud and at the same time. Since stars of different masses evolve at different rates, it is possible to measure the age of globular clusters with a reasonably good accuracy. The oldest ones are found to be more than 13,000 million years old.

Still, those cluster stars were not the first stars to be formed in the Milky Way. We know this, because they contain small amounts of certain chemical elements which must have been synthesized in an earlier generation of massive stars that exploded as supernovae after a short and energetic life. The processed material was deposited in the clouds from which the next generations of stars were made.

Despite intensive searches, it has until now not been possible to find less massive stars of this first generation that might still be shining today. Hence, we do not know when these first stars were formed. For the time being, we can only say that the Milky Way must be older than the oldest globular cluster stars.

But how much older?

Beryllium to the rescue

What astrophysicists would like to have is therefore a method to measure the time interval between the formation of the first stars in the Milky Way (of which many quickly became supernovae) and the moment when the stars in a globular cluster of known age were formed. The sum of this time interval and the age of those stars would then be the age of the Milky Way.

New observations with the VLT at ESO's Paranal Observatory have now produced a break-through in this direction. The magic element is "Beryllium"!

Beryllium is one of the lightest elements - the nucleus of the most common and stable isotope (Beryllium-9) consists of four protons and five neutrons. Only hydrogen, helium and lithium are lighter. But while those three were produced during the Big Bang, and while most of the heavier elements were produced later in the interior of stars, Beryllium-9 can only be produced by "cosmic spallation". That is, by fragmentation of fast-moving heavier nuclei - originating in the mentioned supernovae explosions and referred to as energetic "galactic cosmic rays" - when they collide with light nuclei (mostly protons and alpha particles, i.e. hydrogen and helium nuclei) in the interstellar medium.

Galactic cosmic rays and the Beryllium clock

The galactic cosmic rays travelled all over the early Milky Way, guided by the cosmic magnetic field. The resulting production of Beryllium was quite uniform within the galaxy. The amount of Beryllium increased with time and this is why it might act as a "cosmic clock".

The longer the time that passed between the formation of the first stars (or, more correctly, their quick demise in supernovae explosions) and the formation of the globular cluster stars, the higher was the Beryllium content in the interstellar medium from which they were formed. Thus, assuming that this Beryllium is preserved in the stellar atmosphere, the more Beryllium is found in such a star, the longer is the time interval between the formation of the first stars and of this star.

The Beryllium may therefore provide us with unique and crucial information about the duration of the early stages of the Milky Way.

A very difficult observation

So far, so good. The theoretical foundations for this dating method were developed during the past three decades and all what is needed is then to measure the Beryllium content in some globular cluster stars.

But this is not as simple as it sounds! The main problem is that Beryllium is destroyed at temperatures above a few million degrees. When a star evolves towards the luminous giant phase, violent motion (convection) sets in, the gas in the upper stellar atmosphere gets into contact with the hot interior gas in which all Beryllium has been destroyed and the initial Beryllium content in the stellar atmosphere is thus significantly diluted. To use the Beryllium clock, it is therefore necessary to measure the content of this element in less massive, less evolved stars in the globular cluster. And these so-called "turn-off (TO) stars" are intrinsically faint.

In fact, the technical problem to overcome is three-fold: First, all globular clusters are quite far away and as the stars to be measured are intrinsically faint, they appear quite faint in the sky. Even in NGC6397, the second closest globular cluster, the TO stars have a visual magnitude of ~16, or 10000 times fainter than the faintest star visible to the unaided eye. Secondly, there are only two Beryllium signatures (spectral lines) visible in the stellar spectrum and as these old stars do contain comparatively little Beryllium, those lines are very weak, especially when compared to neighbouring spectral lines from other elements. And third, the two Beryllium lines are situated in a little explored spectral region at wavelength 313 nm, i.e., in the ultraviolet part of the spectrum that is strongly affected by absorption in the terrestrial atmosphere near the cut-off at 300 nm, below which observations from the ground are no longer possible.

It is thus no wonder that such observations had never been made before, the technical difficulties were simply unsurmountable.

VLT and UVES do the job

Using the high-performance UVES spectrometer on the 8.2-m Kuyen telescope of ESO's Very Large Telescope at the Paranal Observatory (Chile) which is particularly sensitive to ultraviolet light, a team of ESO and Italian astronomers succeeded in obtaining the first reliable measurements of the Beryllium content in two TO-stars (denoted "A0228" and "A2111") in the globular cluster NGC 6397. Located at a distance of about 7,200 light-years in the direction of a rich stellar field in the southern constellation Ara, it is one of the two nearest stellar clusters of this type; the other is Messier 4.

The observations were done during several nights in the course of 2003. Totalling more than 10 hours of exposure on each of the 16th-magnitude stars, they pushed the VLT and UVES towards the technical limit. Reflecting on the technological progress, the leader of the team, ESO-astronomer Luca Pasquini, is elated: "Just a few years ago, any observation like this would have been impossible and just remained an astronomer's dream!"

The resulting spectra of the faint stars show the weak signatures of Beryllium ions (Be II). Comparing the observed spectrum with a series of synthetic spectra with different Beryllium content (in astrophysics: "abundance") allowed the astronomers to find the best fit and thus to measure the very small amount of Beryllium in these stars: for each Beryllium atom there are about 2,224,000,000,000 hydrogen atoms.

Beryllium lines are also seen in another star of the same type as these stars, HD 218052. However, it is not a member of a cluster and its age is by far not as well known as that of the cluster stars. Its Beryllium content is quite similar to that of the cluster stars, indicating that this field star was born at about the same time as the cluster.

From the Big Bang until now

According to the best current spallation theories, the measured amount of Beryllium must have accumulated in the course of 200 - 300 million years. Italian astronomer Daniele Galli, another member of the team, does the calculation: "So now we know that the age of the Milky Way is this much more than the age of that globular cluster - our galaxy must therefore be 13,600 +- 800 million years old. This is the first time we have obtained an independent determination of this fundamental value!".

Within the given uncertainties, this number also fits very well with the current estimate of the age of the Universe, 13,700 million years, that is the time elapsed since the Big Bang. It thus appears that the first generation of stars in the Milky Way galaxy was formed at about the time the "Dark Ages" ended, now believed to be some 200 million years after the Big Bang.

It would seem that the system in which we live may indeed be one of the "founding" members of the galaxy population in the Universe

index from: spaceflightnow.com

http://http://www.spaceflightnow.com/news/n0408/17milkyway/


New moons for Saturn

New moons for Saturn
August 16, 2004
The Cassini spacecraft has discovered a pair of 2-mile-wide moons, mission scientists announced today. The satellites, provisionally named S/2004 S1 and S/2004 S2, are the smallest bodies so far seen around the ringed planet. The finds raise Saturn's known number of moons to 33.

As Cassini fell toward Saturn in early June, scientists began using the spacecraft's cameras to scan for new satellites. "One of our major objectives in returning to Saturn was to survey the entire system for new bodies," said Carolyn Porco, leader of Cassini's imaging team at the Space Science Institute, in Boulder, Colorado. "So it's really gratifying to know that among all the other fantastic discoveries we will make over the next 4 years, we can now add the confirmation of two new moons, skipping unnoticed around Saturn for billions of years until just now."

Sebastien Charnoz, a planetary dynamicist working with Andre Brahic, a Cassini imaging team member at the University of Paris, found the new moons. "Discovering these faint satellites was an exciting experience, especially the feeling of being the first person to see a new body of our solar system," Charnoz said. For weeks from his Paris office, Charnoz had searched Cassini images for saturnian moons using a special computer program, but he didn't score a hit until he went on vacation with his laptop. "This tells me I should take more holidays," he joked.

Both of the new moons orbit Saturn in a little more than one Earth day. S/2004 S1 and S/2004 S2 are, respectively, about 2 miles (3 kilometers) and 2.5 miles (4 km) across, orbiting 120,000 miles (194,000 km) and 131,000 miles (211,000 km) from Saturn's center. This places them between the two large saturnian moons Mimas and Enceladus. From Earth, the new moons appear fainter than magnitude 22.

Scientists are investigating a possibility that S/2004 S1 is actually a recovery of an object first detected by the Voyager spacecraft 23 years ago. That object, dubbed S/1981 S14, appeared in a single image taken August 23, 1981.

Before today's announcement, the smallest moons known to orbit Saturn were about 12 miles (20 km) across. Scientists expect to find small moons within the gaps in Saturn's rings, where their gravitational pull helps clear out particles and maintain the gaps. Finding a pair of moonlets beyond the rings, between two major moons, is something of a surprise.

Cassini scientists are trying to improve their views of S/2004 S1 and S/2004 S2 even as they continue the search for additional moons. "We are at this very moment looking to see what the best times are for retargeting," Porco said. "Hopefully, we haven't seen the last of them."
http://www.astronomy.com/default.aspx?c=a&id=2384

Saturday, August 14, 2004

today picture: x price gift and future winers


The Canadian Arrow astronauts -- Back row (from left): Larry Clark, Jason Dyer and Yaroslav "Yarko" Pustovyi. Front row (from left): Capt. David Ballinger (ret), Terry Wong and Capt. Ted Gow. Credit: Canadian Arrow. Clilk to larger image

have nice time perusus good meteor


Tuesday, August 10, 2004

pictures of the day: mars rovers picture

in "Endurance Crater" opportunity

As NASA's Mars Exploration Rover Opportunity creeps farther into "Endurance Crater," the dune field on the crater floor appears even more dramatic. This false-color image taken by the rover's panoramic camera shows that the dune crests have accumulated more dust than the flanks of the dunes and the flat surfaces between them. Also evident is a "blue" tint on the flat surfaces as compared to the dune flanks. This results from the presence of the hematite-containing spherules ("blueberries") that accumulate on the flat surfaces.

Sinuous tendrils of sand less than 1 meter (3.3 feet) high extend from the main dune field toward the rover. Scientists hope to send the rover down to one of these tendrils in an effort to learn more about the characteristics of the dunes. Dunes are a common feature across the surface of Mars, and knowledge gleaned from investigating the Endurance dunes close-up may apply to similar dunes elsewhere.

Before the rover heads down to the dunes, rover drivers must first establish whether the slippery slope that leads to them is firm enough to ensure a successful drive back out of the crater. Otherwise, such hazards might make the dune field a true sand trap.
AND SPRIT
IN COLOMBIA



New NASA Supercomputer to Aid Theorists and Shuttle Engineers

NASA researchers have teamed up with a pair of Silicon Valley firms to build a supercomputer that ranks alongside the world's largest Linux-based systems.
When complete, the Space Exploration Simulator supercomputer will provide 10 times the data-crunching power of NASA's current supercomputer capacity.
"Our space scientists in the past were starved for [computer] cycles," said Walter Brooks, chief of the NASA Advanced Supercomputing (NAS) division. "Sometimes people would submit an idea and it would take weeks to get an answer."
Brooks told SPACE.com the new system will allow scientists to run complicated computer models, such as those used for research into planetary formation or solar physics, alongside the meticulous space shuttle engineering studies critical for NASA's return to flight.
NASA's Ames Research Center in Mountain View, California -- home to NAS -- is developing the new supercomputing system as part of its collaborative Project Columbia with the aid of Silicon Graphics, Inc. (SGI) and the Intel Corp. in the Silicon Valley.
Plans call for a network of 20 powerful SGI Altix computers, each with 512-processor systems, equipped with 500 terabytes of local data storage. Once the computers are linked, their 10,240 Intel Itanium 2 processors will power the Space Exploration Simulator over a wide range of studies, including space shuttle modeling, climate change, mission safety and aeronautics.
"This will enable NASA to meet its immediate mission-critical requirements for return to flight, while building a strong foundation for our space exploration vision and future missions," NASA Administrator Sean O'Keefe said in a statement.
During the Columbia investigation, engineering and shuttle computer models took up most of NASA's supercomputing capacity, leaving Earth and space science studies by the wayside. With the new system, a single computer node can handle the return to flight shuttle modeling requirements, opening the rest for scientific research. The space agency also plans to allow the public science and engineering communities access to a portion of the Space Exploration Simulator for their own studies.
Ames and SGI researchers already had one 512-processor Linux computer -- built last year -- named Kalpana in honor of astronaut Kalpana Chawla who died with her fellow crewmates in the Columbia accident. A second machine has been linked to it, with the remaining 18 expected to follow over the next three months.
Since the Space Exploration Simulator relies on off-the-shelf technology, researchers can upgrade the system as more advanced computer chips and processors become available. Those internal upgrades are key, since the 20-computer system has consumed the available space at Ames.
"NASA, 20 years ago, led the way in computing," Brooks said. "When you're building the world's most complex vehicle, tackling hard problems like debris and crew escape…we need that kind of computing ability."

by www.space.com

Sunday, August 08, 2004

Hubble Trouble: One of Four Instruments Stops Working

One of the four astronomical instruments on the Hubble Space Telescope shut down earlier this week and engineers are trying to pin down the problem. The other three instruments continue to operate normally.
The instrument, called the Space Telescope Imaging Spectrograph (STIS), does not make the classic pictures that Hubble is famous for, but instead splits light into its constituent colors. It has been used to discover dim stars that reveal clues about the age of the universe, study planet-forming environments around other stars and provide insight into black holes.
The STIS stopped working Tuesday, Aug. 3, going into what officials call a suspended mode, according to a NASA statement released Friday. Mission managers think there is a malfunction in a power converter. It is not known if the glitch can be fixed.
The spectrograph was installed during the second Hubble servicing mission, in 1997. It was designed to operate for five years. NASA says it has met or exceeded all its scientific requirements.
NASA has convened an Anomaly Review Board to investigate the problem and determine if the instrument is recoverable.
"A final decision on how to proceed is expected in the coming weeks as analysis of the problem progresses," according to the statement.
The instrument is not slated for replacement by the next servicing effort. That mission, which NASA Administrator Sean O'Keefe cancelled in January due to safety concerns for the space shuttle fleet, is up in the air right now. O'Keefe reconsidered his decision and said a robotic mission might be undertaken, though he continues to resist expert suggestions that a manned shuttle mission to service the telescope remain a serious option.
Hubble's other instruments -- the Near Infrared Camera and Multi-Object Spectrometer (NICMOS), the Advanced Camera for Surveys, and the Wide Field/Planetary Camera 2 -- are not affected by the problem.
The STIS is used for about 30 percent of Hubble's observing time. A standby list of targets for the other three instruments will likely take up that time.
Hubble has otherwise been in good health. But its batteries and pointing gyroscopes are expected to fail in the next two to three years. If they are not replaced by a robotic or human servicing mission, Hubble will likely cease operations by 2008, engineers have concluded.
more: www.hubblesite.org
www.space.com