Universe Today : SETI@home Needs You!

Written by Nancy Atkinson

If your New Year’s resolutions include trying something new, expanding your horizons, or doing something to benefit humanity, this is for you: SETI@home needs more volunteers to help crunch data in the search for extraterrestrial intelligence (SETI). And the easy part is that your desktop computer does all the work.

SETI uses radio telescopes to listen for narrow band-width radio signals from space. Since these signals don’t occur naturally, a detection of such a signal would indicate technology from an extraterrestrial source.

The SETI project at the University of California-Berkley gets data from world's largest radio telescope in Arecibo, Puerto Rico, which has recently been updated with seven new and more sensitive receivers. The improved frequency coverage for the telescope is now generating 500 times more data for the SETI project than before, and more volunteers are needed to handle the increase in data.

According to project scientist Eric Korpela, the new data amounts to 300 gigabytes per day, or 100 terabytes (100,000 gigabytes) per year, about the amount of data stored in the U.S. Library of Congress. "That's why we need all the volunteers," he said. "Everyone has a chance to be part of the largest public participation science project in history."

The SETI@home premise is simple but brilliant: Instead of using a monstrously huge and expensive supercomputer to analyze all the data, it uses lots of small computers, all working simultaneously on different parts of the analysis. Participants download a special screensaver for their home computers, and when the computer is idle, the screensaver kicks in to grab data from UC Berkley, analyze the data and send back a report. SETI@home was launched in May of 1999.

The SETI@home software has now been upgraded to deal with all the new data generated by the updated Arecibo telescope. The telescope can now record radio signals from seven regions of the sky simultaneously instead of just one. It also has greater sensitivity and 40 times more frequency coverage.

So, if the phrase “to search out new life and new civilizations” inspires you, here’s your chance to be part of the largest community of dedicated users of any internet computing project. Currently SETI@home has 170,000 individuals donating time on 320,000 computers.

"Earthlings are just getting started looking at the frequencies in the sky; we're looking only at the cosmically brightest sources, hoping we are scanning the right radio channels," said project chief scientist Dan Werthimer. "The good news is, we're entering an era when we will be able to scan billions of channels. Arecibo is now optimized for this kind of search, so if there are signals out there, we or our volunteers will find them."

Check out SETI@home here.
Original News Source: UC Berkley Press Release

Universe Today : Carnival of Space #35

Written by Fraser Cain

We took a bit of a break over the holidays, but we're back with the Carnival of Space #35. This week it's over at the Music of the Spheres. And there's a second bonus edition with a few entries that I somehow let slip through the cracks.

Should we reach out to extraterrestrials, or just keep our mouths shut? Is Asteroid 2007 WD5 going to hit Mars later this month? These topics and more are covered in a collection of space and astronomy stories, so check them out.

And if you're interested in looking back, here's an archive to all the past carnivals of space. If you've got a space-related blog, you should really join the carnival. Just email an entry to carnivalofspace@gmail.com, and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community - and community is what blogging is all about. And if you really want to help out, let me know if you can be a host, and I'll schedule you into the calendar.

Universe Today : The Moon Meets Antares On January 5

Written by Tammy Plotner

Although no one likes to get up early, it will be worth it on the morning of January 5. For dedicated SkyWatchers, you'll enjoy the pleasing view of Venus and the last phases of the waning Moon… But look closely, because you'll see brilliant red Antares is also joining the show! Whenever a bright star like Antares is so close to the lunar limb, chances are an occultation event is about to happen for some area of the Earth. Would you like to learn more? A photographic and scientific opportunity awaits you!

Less than half a degree away from the lighted edge of the crescent Moon, Antares will make a picturesque scene for many of us that only nature can create. For a few lucky viewers in the south-western portion of South America, this could be an occultation event! If you've ever wondered about occultations, then it's time to learn more about what an occultation is, when it happens, how to view it, record and report.

Several times a year the natural progress of the Moon against the progress of the starry background means a chance to see the lunar disk occult (or cover up) a bright star or planet. If the object is bright enough, you can watch this happen with only your eyes, but even binoculars or a small telescope will greatly improve the view. What a pleasure it is to see a star simply disappear behind the Moon's limb! But it's not just the Moon that occults stars - so do asteroids. Occultations happen anytime one celestial body passes in front of another - a type of eclipse. For those of you who enjoy doing a little bit of science, there's a whole lot more to do… and contributions you can make!

Thanks to great folks at the International Occultation Timing Association (IOTA), you can learn how to predict, time, record and submit your observations by downloading the free ebook: "Chasing the Shadow: The IOTA Occultation Observer's Manual - The Complete Guide to Observing Lunar, Grazing and Asteroid Occultations" available here! It's the only book of its kind that shows observers how to get started in occultations and what equipment to use. Whether you are a novice observer, or an advanced observer with a video system, you can assist in the search for asteroidal moons, help discover new double stars and help determine the size of the Sun during solar eclipses.

Let the beauty of the morning on January 5 inspire you! During the month of January you'll be treated to great things like an occultation of the Pleiades stars on January 18 in northern North America and Northern Asia. On January 19 in southern Africa you'll see Beta Tauri disappear. If you live in Alaska, January 20 means an occultation of Mars. For southern observers in Australia and New Zealand, be sure to check out the Moon and Regulus on January 24. To get times and locations, all you have to do is check with IOTA. If watching a asteroid pass in front of a star takes your fancy, then stop by here where you can get multitudes of information for events in your area!

In the meantime, get your cameras and fingers ready. We'd like to share in your success! See if you can capture the view on the morning of January 5 and post it here. Even if you're not able to photograph the event, we'd love to hear your reports and impressions. Watch the "Universe Today" in future months as we bring you more!

Space.com : Old Comets for a New Year

By Joe Rao SPACE.com Skywatching Columnist posted: 04 January 2008 06:24 am ET

As we kick off the year 2008, Comet Tuttle is putting on a nice show for backyard skywatchers. It had not been seen since 1994, but you'll have an excellent opportunity to pick it up with binoculars or small telescopes during the next two weeks.

Tuttle can even be glimpsed by sharp-eyed observers under pristine skies without any optical aids, for it is one of the brightest of the short-period comets, those that orbit the sun often enough to be seen again and again from Earth and identified as such.

And speaking of short-period comets, Comet Holmes continues to delight observers more than two months after its stupendous explosion to naked-eye visibility.

Discovery

As we all know, Halley's was the first comet-to be recognized as periodic, but it had been seen on many previous returns before Edmund Halley announced that fact in the year 1705. Similarly, although Encke's comet was discovered in 1786, it was observed on three more returns before Johann Franz Encke determined that it had an orbital period of 3.3-years.

The object that we today call Comet Tuttle had a similar history.

On Jan. 9, 1790, the renowned Parisian comet hunter Pierre Méchain discovered a fairly bright telescopic comet in the western evening sky. His friend and rival Charles Messier described it on the following night as resembling an unresolved star cluster or nebula without a nucleus. It was followed for just over three weeks; just not enough time for a sufficient number of observations to determine an accurate orbit.

Astronomers assumed that the object was traveling in a parabolic orbit and would never be seen again, and entered the literature simply as "Comet 1790 II." It wasn't to be seen again for nearly 70-years.

Tuttle's turn

Horace P. Tuttle, an assistant at Harvard College Observatory, discovered three comets by telescope during the year 1858. Tuttle found the first of them on Jan. 4 in the constellation Andromeda. Still approaching the perihelion point of its orbit (its least distance from the sun), the comet was favorably placed relative to the Earth, and this made possible a long series of positional measurements.

Comet Tuttle was brightest during February at about magnitude 7, meaning it was just below the threshold of naked eye visibility, though a relatively easy object to see with binoculars or a small telescope.

Tuttle himself was among the first to suggest that his object was identical with Comet 1790 II. A 13.7-year period was proposed by several astronomers, and it soon became clear that Comet Tuttle of 1858 had been missed at four intervening apparitions. At three of those returns (1803, 1817, and 1844) it was too close to the sun in the sky to be seen, while conversely, in 1830 it should have been an easy object in the morning sky but was somehow missed.

Comet Tuttle became the eighth comet to be recognized as a periodic object hence it is now designated as 8P/Tuttle.

The perihelion distance of 8P/Tuttle places it just outside of the Earth's orbit at 95.5 million miles (153.6 million kilometers). Also, around Dec. 22 of each year the Earth passes through the dusty trail left behind by the comet from its previous visits. This encounter gives rise to an annual display of meteors known as the Ursids, which appear to diverge from near the bright star Kochab in the bowl of the Little Dipper.

Because 8P/Tuttle was observed at each return following its 1858 rediscovery except in 1953, this time around will go down in the record books as its 12th observed apparition. And as it turns out, this apparition will be among its very best.

Where and when to look

On New Year's Day, 8P/Tuttle passed closest to Earth; a distance of 23.5 million miles (37.8 million kilometers). Although it is now slowly moving away from the Earth, it will continue to slowly approach the sun, passing closest to it on Jan. 27. Comets are most visible when they near the sun, which lights up material that boils off the comet.

So, during these next two weeks, the comet will hold nearly steady in brightness at around magnitude 6. For those blessed with clear, dark skies far from significant light pollution, the comet might be even glimpsed with the unaided eye. But good binoculars or a small telescope will easily bring 8P/Tuttle into view if you know where to train them; it should appear as a small fuzzy star possibly sporting a faint, narrow tail.

The comet will be situated against the rather dim stars that compose the so-called "watery region" of the sky, passing through eastern Pisces (the fishes) into Cetus (the whale) during the night of Jan. 6-7. On that night, it will lie not far to the west from one of the brightest stars in Pisces: fourth magnitude, Al Rischa, located at the point where the two fish are tied. In fact, the name comes from the Arabic word for "cord."

For the next couple of weeks both Pisces and Cetus can be conveniently found well up in the southern sky between 6 to 8 p.m. local standard time.

Comet 8P/Tuttle will appear to skid south in its orbit against the background stars of these two constellations. After moving through Cetus, 8P/Tuttle will pass into the dim, shapeless constellation of Fornax (the furnace) on Jan. 16. It will continue to plunge south thereafter, gradually becoming unfavorably placed for viewers in the Northern Hemisphere, although those living south of the equator will be able to follow the now fading comet right on into February.

A reminder about Comet Holmes!

While the spotlight is now on Comet Tuttle, we should not forget about our old friend, Comet Holmes which continues to be dimly visible to the unaided eye as a diffuse, circular cloud, roughly twice the apparent diameter of the moon against the stars of the constellation Perseus.

This comet was no brighter than magnitude 17 in mid-October — that's about 25,000 times fainter than the faintest star that can normally be seen without any optical aid. But late on Oct. 23, the comet's brightness suddenly rocketed all the way up to magnitude 2.5, brightening nearly one million times in less than 24 hours!

In attempting to explain why Comet Holmes exploded, comet expert, John Bortle suggested that this comet's nucleus consists of low-density material that, over time developed into a large region with a very tenuous structure, like a honeycomb. At some point, the highly fragile bonds connecting the honeycomb of material reached a failing point and a sudden crushing collapse occurred, expelling a gigantic volume of dust into space, making this dim comet suddenly appear impressively bright.

Back in 1892, Comet Holmes suffered two major outbursts separated by about 75 days. This leads to the question as to whether this comet will undergo a similar "cosmic aftershock" in the wake of its recent late October explosion.

Bortle thinks it's a possibility, based on the theory that there may be a large amount of residual instability which might lead to a second major collapse of material on the comet nucleus. If what happens now parallels what happened in 1892, another possible explosive outburst may be imminent, so it might be wise to keep a close watch on Comet Holmes in the coming days ahead.

• Online Sky Maps and More
• Sky Calendar & Moon Phases
• Astrophotography 101

Space.com : 4 Years on Mars: Rovers Continue to Amaze

By Dave Mosher Staff Writer posted: 03 January 2008 06:28 am ET

Two robots the size of golf carts were given 90 days to squeeze as much science as possible from the barren, dust-swept terrain of Mars. After that, scientists expected nothing more from them than death.

Nearly four years after their warranties expired, however, the Mars Explorations Rovers (MERs) "Spirit" and "Opportunity" continue to play productively in the red dirt.

Spirit celebrates its fourth anniversary of Martian work on Jan. 4, the day it landed in 2004, followed by Opportunity on Jan. 25. Those four Earth years since landing convert to 2.25 Martian years, or 1,422 Martian days called "sols."

"We never thought we'd still be driving these robots all over Mars," said Mark Lemmon, a planetary scientist at Texas A&M University and member of the rover science team. "We joked about driving Opportunity into Victoria Crater, but now we're there, and we're looking at doing even more science. Each day they still work is an amazing one."

Happy anniversary

Since the rovers bounced onto Mars' surface, they have collectively driven more than 11.8 miles (19.1 kilometers) and snapped more than 210,000 images. That's roughly 55 standard DVD movies worth of uncompressed data.

Scientists have used this information through the years to crank out more than 100 studies about the planet's geologic past "with many more in progress," Lemmon said.

"It's been a great year for the rovers and we're getting deeper into Martian history than we've ... done before," Lemmon said. "These robots have entirely changed the way we view Mars."

Those views include support for the existence of water on Mars, at least in the past, in the form of silica and meteorites.

In addition to that evidence, the year 2007 inflicted a global dust storm on the rovers. Although indirect sunlight powered the rovers through the dusty conditions, more than 96 percent of direct sunlight to their solar panels was filtered out.

"It was scary there for a while," Lemmon said of the low-light conditions that nearly drove the rovers to a permanent standstill.

Despite the nerve-wracking task of keeping both rovers power-positive — and their electronic circuits from snapping in the Martian cold — Lemmon explained that new science is still trickling out as a result of the weather event.

"The Mars orbiters looked down on the dust storm when it happened, but they didn't measure changes on the ground like the rovers did," he said. "The rovers are really helping us to better understand these storms."

Winter parking spot

Now that the dusty, five- to six-month Martian summer is waning and winter is creeping up, earthly operators have pinned down an over-winter parking spot for Spirit.

The rover suffered software glitches early in the mission, and now drives backward as its front right wheel is indefinitely stuck. Making matters worse is the literal fallout from the recent dust storm.

"Right now, we're working with the dustiest rover we've ever had," Lemmon said, who does not expect whirling dust devils to clean off the rover's coated solar panels any time soon. "As a result, we pretty much consider Spirit parked."

Lemmon said Opportunity, however, is in good shape to continue exploring and the team has no definitive date for parking the adventurous machine.

"Opportunity has much cleaner [solar panels] than Spirit," Lemmon said, "so there's no discussion of racing it to a north-facing slope for the winter."

Scientists used the north-facing-slope trick in the past, which helps maximize direct sunlight to the rover's solar panels during the dim Martian winter.

While Opportunity continues to maneuver around Victoria Crater, Spirit is presently resting on a slope of Home Plate — a layered outcrop of rock in the shape of a baseball home plate. "It'll stay in one place for a long time, but we'll still be able to do some science," Lemmon said.

That science includes watching the sky for water-crystal clouds and taking atmospheric measurements, but the rover may also witness a potential asteroid impact later this month.

"I'm not optimistic for the rovers seeing anything ... [but] we have some hope of seeing the impact cloud as it disperses around the planet," Lemmon said. "I like the thought of a birthday present from Mars. It'll certainly contribute more excitement to the mission."

• Video: Mars Rover Team Ponders Mission's End
• Video: Mars Rover Dynasty
• Vote: The Best of the Mars Rovers

Astronomy Magazine : White dwarf pulses like a pulsar

Current knowledge of white dwarfs is being challenged by new discoveries.

Provided by NASA's Goddard Space Flight Center

The white dwarf in the AE Aquarii system is the first star of its type known to give off pulsar-like pulsations that are powered by its rotation and particle acceleration. Casey Reed [View Larger Image] January 3, 2008 New observations from Suzaku, a joint Japanese Aerospace Exploration Agency (JAXA) and NASA X-ray observatory, have challenged scientists' conventional understanding of white dwarfs. Observers had believed white dwarfs were inert stellar corpses that slowly cool and fade away, but the new data tell a completely different story. At least one white dwarf, known as AE Aquarii, emits pulses of high-energy (hard) X-rays as it whirls around on its axis. "We're seeing behavior like the pulsar in the Crab Nebula, but we're seeing it in a white dwarf," says Koji Mukai of NASA Goddard Space Flight Center in Greenbelt, Maryland. The Crab Nebula is the shattered remnant of a massive star that ended its life in a supernova explosion. "This is the first time such pulsar-like behavior has ever been observed in a white dwarf." White dwarfs and pulsars represent distinct classes of compact objects that are born in the wake of stellar death. A white dwarf forms when a star similar in mass to the Sun runs out of nuclear fuel. As the outer layers puff off into space, the core gravitationally contracts into a sphere about the size of Earth, but with roughly the mass of the Sun. The white dwarf starts off scorching hot from the star's residual heat. But with nothing to sustain nuclear reactions, it slowly cools over billions of years, eventually fading to near invisibility as a black dwarf. A pulsar is a type of neutron star, a collapsed core of an extremely massive star that exploded in a supernova. Whereas white dwarfs have incredibly high densities by earthly standards, neutron stars are even denser, cramming roughly 1.3 solar masses into a city-sized sphere. Pulsars give off radio and X-ray pulsations in lighthouse-like beams.

An artist depicts the Suzaku X-ray observatory in Earth's orbit. JAXA [View Larger Image] The discovery team, led by Yukikatsu Terada of the Institute of Physical and Chemical Research (RIKEN) in Wako, Japan, was not expecting to find a white dwarf mimicking a pulsar. Instead, the astronomers were hoping to find out if white dwarfs could accelerate charged subatomic particles to near-light speed, meaning they could be responsible for many of the cosmic rays that zip through our galaxy and occasionally strike Earth. Some white dwarfs, including AE Aquarii, spin very rapidly and have magnetic fields millions of times stronger than Earth's. These characteristics give them the energy to generate cosmic rays. To find out if this is happening, Terada and his colleagues targeted AE Aquarii with Suzaku in October 2005 and October 2006. The white dwarf resides in a binary system with a normal companion star. Gas from the star spirals toward the white dwarf and heats up, giving off a glow of low-energy (soft) X-rays. But Suzaku also detected sharp pulses of hard X-rays. After analyzing the data, the team realized that the hard X-ray pulses match the white dwarf's spin period of once every 33 seconds. The hard X-ray pulsations are very similar to those of the pulsar in the center of the Crab Nebula. In both objects, the pulses appear to be radiated like a lighthouse beam, and a rotating magnetic field is thought to be controlling the beam. Astronomers think that the extremely powerful magnetic fields are trapping charged particles and then flinging them outward at near-light speed. When the particles interact with the magnetic field, they radiate X-rays. "AE Aquarii seems to be a white dwarf equivalent of a pulsar," says Terada. "Since pulsars are known to be sources of cosmic rays, this means that white dwarfs should be quiet but numerous particle accelerators, contributing many of the low-energy cosmic rays in our galaxy." Launched in 2005, Suzaku is the fifth in a series of Japanese satellites devoted to studying celestial X-ray sources. Managed by JAXA, this mission is a collaborative effort between Japanese universities and institutions and Goddard.

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Space.com : Hot on the Trail of Cosmic Rays

By Jeremy Hsu Staff Writer posted: 02 January 2008 06:31 am ET

The mysterious origins of cosmic rays that slam into the Earth's atmosphere could soon be revealed, thanks to a better ground-based sensor that costs less than balloons or satellites.

Cosmic rays are thought to come from either the center of the galaxy or a nearby supernova, and knowing which is true will help astrophysicists paint a more accurate picture of the cosmos.

"Cosmic rays are not a spectator phenomenon in the galaxy — they have a role in galactic dynamics," said Scott Wakely, a University of Chicago physicist. "To understand the galaxy in a full sense, you need to understand cosmic rays."

That understanding depends on ground and space-based instruments. Satellites and balloons first detect a blue flash — known as Cerenkov radiation — when cosmic rays smash into the upper atmosphere and release energy.

The cosmic ray particles then break into a shower of smaller pieces and produce a second blue flash. Ground sensors usually only detect the second flash.

Tens of thousands of particles may bombard an area the size of a small parking lot on Earth daily, while rarer high-energy particles strike less than once a year in the same area. Satellites and balloons do a better job of detection by rising above the atmosphere, but they can only cover a small area.

"A $400 million satellite is only a couple particles per year, and you want hundreds of thousands," Wakely told SPACE.com. "You always want to look for new ways to do this."

Wakely set out with colleague Simon Swordy, a physicist at the University of Chicago, to create a ground-based instrument that could detect both the first and second blue flashes. The instrument will have roughly 10 times the resolution and power of current ground-based detectors.

Scientists can use information from both blue flashes to identify a particle as a certain element and maybe even its origin. For instance, some elements will more likely come from the fiery outburst of a supernova.

"We can say that was iron or that was uranium," noted Wakely. "Those are the kinds of data you need to make progress in this business."

No one thought ground-based instruments could detect the first blue flash, until Wakely and Swordy proposed the idea with other colleagues in 2001. A team of researchers in Namibia confirmed the concept using a telescope array called HESS. Wakely later made his own observations using a telescope array called VERITAS.

"That was direct evidence that it [the technique] works," said Wakely. "The goal of this [new] instrument is to combine large area detection with the high precision of space-based sensors."

An improved instrument could also help solve at least one mystery about the energy range of cosmic ray particles. Higher energy particles — such as those from the nuclei of heavy elements like iron — are rarer than common, lower-energy particles such as protons. But physicists have puzzled over a sudden drop-off in frequency of high-energy particles at a certain point in the energy spectrum, labeling the strange kink "the Knee" because of its shape.

Some researchers suggest that supernovas which they claim produced all the cosmic rays suddenly run out of energy at "the Knee," and a new source of cosmic rays takes over on the other side. Others think that a new model of physics takes over that is beyond current scientific understanding, but no one knows for sure, without more measurements of high-energy particles from "the Knee" region.

If all goes well, Wakely and Swordy plan to submit a proposal in three years to build the instrument they are designing. The National Science Foundation has already given a five-year, $625,000 grant to start drawing up the concept.

• VIDEO: Supernova: Creator/Destroyer
• Top 10 Strangest Things in Space
• Astronomers Describe Cosmic Pinball Machine

Space Weather

METEOR SHOWER: Earth is about to pass through a debris stream from near-Earth asteroid 2003 EH1, producing the annual Quadrantid meteor shower. Forecasters expect a brief but intense peak of 50+ meteors per hour over Earth's northern hemisphere sometime between 0200 UTC and 0700 UTC on Friday morning, Jan. 4th. (Subtract 5 hours to convert UTC to EST.) The timing favors observers in the eastern USA, Europe and western parts of Asia: sky map.

Winter storms frequently hide this shower from observers on the ground. To avoid such problems, a team of astronomers led by Peter Jenniskens of the SETI Institute will fly a plane above the clouds where they can train their cameras on the Quadrantids. Their data may reveal whether asteroid 2003 EH1 is a fragment of a long-dead comet: more.

ORION--WARP 5! "While at the San Antonio Astronomical Association's New Year Eve Star Party, I was taking a widefield image of Orion and thought that I would vary the focal length of the lens," says Bryan Tobias of Fredericksburg, Texas. "This is what I ended up with!"

Photo details: Nikon D300, 14-24mm lens, f/2.8, ISO 1600 20 seconds

"I call this shot Number 1, Orion--Warp 5!" he says. "I used a Nikon D300 with a Nikon lens at all focal lengths from 14mm to 24mm."

This is a good time of year to see Orion--even at impulse speed. The constellation rises in the east at sunset beneath the campfire-red light of Mars: sky map. Watching Orion ascend, you may experience the little-known "constellation illusion." The idea is the same as the Moon illusion; constellations viewed near the horizon look abnormally large. Go outside tonight and look. Can you believe your eyes?

NEW YEARS COMET: Tonight, after sunset, take your binoculars outside and scan the sky right above your head. You may find a little emerald fuzzball--Comet 8P/Tuttle. The comet is making its closest approach to Earth (24 million miles) this week. Shining like a ~6th magnitude star, it is barely visible to the unaided eye, but a fine target for binoculars and backyard telescopes. Sky maps: Jan 2, 3.

On Dec. 30th, in the mountains of northern Italy, Giampaolo Salvato photographed the comet gliding by spiral galaxy M33:

more galaxy-comet encounter photos

"This is a 2 x 5 minute exposure at ISO 1600," says Salvato, who took the picture using his backyard telescope and a Canon 5D digital camera.

The colors in this photo are truly heavenly: The galaxy is blue because of a great number of young and massive blue-white stars outlining the spiral arms. The comet, on the other hand, is green because of cyanogen (CN, a poisonous gas) and diatomic carbon (C₂) present in the comet's atmosphere; both substances glow emerald-green when exposed to UV sunlight in the near vacuum of space.

Universe Today : Shuttle Launch Decision on Tap

Written by Nancy Atkinson

NASA engineers continue to repair a faulty electrical connector on Space Shuttle Atlantis’ external fuel tank which has delayed the launch of the STS-122 mission to the International Space Station. An update of the progress on that work will be presented at a mission management team meeting scheduled for Thursday, January 3 and mission managers will perhaps then be prepared to announce a proposed launch date for Atlantis.

The repairs could take several days or even weeks. At a press briefing last week, shuttle program manager Wayne Hale declined to offer a probable launch date. “We’re in the middle of troubleshooting and repair,” he said. “Until that gets a little bit further along, I actually have no valid dates to give you… To avoid what I think would be a totally misleading headline along the lines of ‘NASA Delays the Space Shuttle Again’ we’re just not going to give you a launch date because that, in fact, would not be accurate.”

The engine cutoff (ECO) fuel sensor system transmitted false readings during two launch countdowns for Atlantis earlier in December. A fueling test performed on December 18 isolated the problem to a 1 ½ -by 3 inch connector called a pass-through connector, located both inside and outside the tank. The wires for all four ECO sensors pass through the same connector. From the data of that test, engineers believe the problem lies in gaps between pins and sockets on the external side of the pass-through connector when the system is chilled to cryogenic temperatures, as when the tank is filled with liquid hydrogen and oxygen.

Engineers have removed the connector and are bench-testing the components in similar cryogenic conditions to try to duplicate the failure. Meanwhile, new hardware is being installed on the tank as the shuttle sits on launchpad 39A at the Kennedy Space Center.

“We have allowed the team that did the troubleshooting to very thoroughly go through all the data,” said Hale. “They have told us they are sure the problems that we’re seeing reside in that series of connectors. Where exactly in that series of connectors is a little bit open to interpretation.”

The connectors on the inside of the tank are being visually inspected. “It is a possibility that the internal connector is involved,” Hale said. “However, all the physics based discussion of the kinds of things that can happen point to something happening on the external connector.” Problems with the internal connector would involve “more invasive” work, Hale said, that could possibly damage the tank.

A similar repair was done to the Atlas rockets several years ago to fix problems with circuitry in the Centaur stage. ECO sensors protect the shuttle's main engines by triggering engine shut down if fuel runs unexpectedly low. The Space shuttle main engines running without fuel would likely result in an explosion.

The STS-112 mission will deliver the European Space Agency’s Columbus science module to the station along with a new crew member Leopold Eyharts from France who will take over for Dan Tani. Tani, whose mother was killed in a car accident on December 19, will return to Earth on Atlantis.

“These repairs and troubleshooting activities will determine when we will launch,” said Hale. “The plan to go forward will take as long as it takes, but we don’t think this will be a long-term thing. Probably something that will take a couple of weeks.”

Universe Today : Controversial NASA Aviation Report Released

Written by Nancy Atkinson

NASA released the results on Dec. 31 from an $11.3 million federal air safety study. The agency previously withheld the report, and came under fire from Congress and news organizations for doing so. Earlier reports said NASA was concerned the data in the report would upset travelers and hurt airline profits. But today NASA administrator Mike Griffin and the head of NASA’s Office of Safety and Mission Assurance Bryan O’Connor said the release of the report was delayed to protect both pilot confidentiality and classified commercial aviation information.

“We came across instances in looking at the raw data where information was contained that could have compromised one of those two things,” said Administrator Griffin. “We determined that an independent review of that data was necessary in order to prevent such compromise.”

A panel led by O’Connor reviewed the 16,000 page report and data such as pilots’ names and other confidential information was redacted.

Also, Griffin said there are questions as to the validity of the data in the report, which has not been peer-reviewed.

“We consider the study was not properly organized and not properly reviewed, and that makes the results very difficult to interpret and to use,” he said. The study was conducted by the Battelle Memorial Institute for NASA.

An independant review of the data will be done in the future by the National Academy of Sciences.

Griffin said the original press release highlighting the refusal to release the data used “inappropriate language” to explain the rationale for not releasing the report.

NASA's survey, the National Aviation Operations Monitoring System (NAOMS), interviewed about 8,000 pilots per year from 2001 until the end of 2004. The program was terminated before moving on to interview flight attendants and air traffic controllers, as originally proposed.

Approximately one million dollars a year was put into this study. Griffin said it is a small fraction of NASA’s overall work, and in retrospect, the study did not receive the attention that it should have.

The report can be found on NASA's website. Its length makes it difficult to wade through the data. Additionally, some portions of the report that have not yet been edited for confidential information have been left out. NASA will release the remainder of the report as soon as possible.

The original plan for the survey never called for NASA to interpret and analyze the data. The study’s purpose was to develop new methodologies for collecting aviation safety data, and then the data would be transitioned to the aviation safety community. “NASA conducts research, and this was one element of such research,” said Griffin. “NASA extended the research, which was originally to be concluded in 2004 in order to properly fund the transition of the data and its review. We’ve gone the extra mile with this data and we’ve gone well beyond our original intentions, which is why we’ve brought it to an end.”

It remains uncertain whether any data from the report will ever be used by the aviation safety community. Griffin said it was his understanding that the FAA has “simply moved on from NAOMS,” and that the FAA has over 150 different programs to provide survey data from individuals involved in all areas of air flight.

While NASA didn’t analyze the data, Griffin offered his opinion of what the report surmises: “What the flying public should understand is that they have approximately the same risk of dying from a lightning strike as they do dying from an air transport accident in the United States, which means to say that this is one of the safest forms of travel that human beings have ever invented, and that no one should think otherwise.”

In testimony to congress earlier this year, Griffin characterized the data in the report as not as valid as he would prefer to have for a NASA report. Griffin said that he still feels that way, and that his concern is that this research work was not properly peer reviewed and the data that was extracted from the survey was not properly vailidated at its conclusion.

The survey purportedly unearthed approximately four times as many engine failures than the FAA has documentation for. “It calls into question the reporting mechanisms rather than the underlying rate of engine failures, which we believe we understand,” Griffin said, adding there are other inconsistencies, as well. “Those kinds of inconsistencies, when we looked at the data, gave us pause for thought, and still do.”

“The value of this will need to be determined by the larger aviation community, which I remind you, does not reside within NASA,”Griffin continued. “All that we at NASA have said is that this survey was not peer reviewed and the data was not validated at its conclusion….its up to others whether or not they believe this research has value.”

Griffin had promised to release the report before the end of 2007, and he did so without compromising confidential information that, by law, NASA is prohibited from releasing.

Griffin said this survey doesn’t cast any doubt in his mind about the safety of aviation in the United States. “I did not, having looked at a snapshot of the data, see anything that the flying public would care about or ought to care about,” he said. “But it’s not for me to prescribe what others may care about. We were asked to release the data and we did that.”

The report can be found on the NASA website.

Original News Source: NASA News Audio