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Showing posts with label Pacific Ocean. Show all posts
Showing posts with label Pacific Ocean. Show all posts

Monday 9 July 2012

China builds nuclear-powered deep-sea station

Not content with ambitious plans to dominate space exploration over the coming decades, China is also looking to master the ocean with the development of a deep-sea station which could be its first step towards large-scale underwater mining.


Plans for the nuclear powered mobile deep-sea station were unveiled earlier this year by China Ship Scientific Research Centre – the state-owned venture whose Jiaolong manned submersible recently reached depths of over 7,000 metres – according to South China Morning Post.

The craft would have dimensions of 60.2m x 15.8m x 9.7m, weigh about 2,600 tonnes, and have enough room for 33 crew members.

It would have propellers to move submarine-like underwater and several ports to allow smaller craft to dock with it, the report said.

On that note, a smaller prototype which could carry 12 crew on an 18-day expedition is currently in production, with an expected delivery date of 2015.

While China’s plans in space appear to revolve heavily around military strategy, its deep sea efforts have more to do with the country finding an answer to its current energy problems.

Drilling for oil and mining copper and other natural resources both appear to be high on the list of China’s deep-sea priorities, although technological limitations may hold back advances in the project for some time, the report claims.

When China wants something it usually succeeds in the end, however, so it would not be out of the question to see the launch of a full-sized deep-sea station by 2030, according to SCMP.

As with most elements of Chinese technology innovation, the PLA is never too far away – this deep-sea project is apparently funded by 863 Program, a hi-tech state scheme.

By Phil Muncaster
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Related post:

China set to launch bigger space programme

Science

China plans nuclear deep-sea mining base


A Chinese company is set to build a nuclear-powered mobile deep-sea station in the western Pacific, according to local reports.

The China Ship Scientific Research Centre's proposed station -- which will have huge propellers to enable free movement in the ocean depths -- will be manned by 33 crew for up to two months at a time and powered by a nuclear reactor.

Its main goal, according to reports in the South China Sea Post, will be to mine for precious metals. The nation, which recently announced it is stockpiling rare earth elements amid fears of shortages, would use the facilities to hunt mainly for copper, lead, zinc, silver, gold and oil.

Underwater mining is typically a costly affair, full of potential dangers and problems. Canadian-owned Nautilus Minerals Inc was the first commercial copper-gold mining venture to be granted permission to explore the Bismarck Sea floor surrounding Papua New Guinea, but has already run into problems with environmentalists warning the mining could destroy marine life and cause devastating oil spills. China's Tongling Non-ferrous Metals Group had signed up as the project's very first customer in April 2012, but a dispute with Papua New Guinea also stands to halt the mining project's 2013 launch completely

The Chinese company appears to be wary of these issues, and is therefore treading carefully, with plans for the bold venture slated for a more reasonable 2030 launch -- according to experts the South China Sea Post spoke to -- and a smaller 12-crew prototype capable of 18-day dives set to launch by 2015. The larger 60-metre-long craft will weigh in at 2,600 tonnes.

In preparation, the China Ship Scientific Research Centre has been engaging in test dives of manned vehicles -- its Jiaolong model reached a record-breaking 7,020 metres at the Mariana Trenchin the Pacific Ocean on the same day that China's Shenzhou-9 spacecraft docked at the Tiangong 1 space station.

Reports suggest that the project is being funded by the state's 863 Program, a fund specifically for the development of innovative technologies, which has links with the military. Nevertheless, mining for oil and copper seem to be the most likely priorities on the agenda, with crew on the station able to spend two months at a time living and mining underwater.

Shanghai is hosting the 41st Underwater Mining Institute conference October 2012, and further details could potentially be revealed then. In the meantime, a look at the China Ship Scientific Research Centre's website reveals fields of interest that range from manned submersibles such as the Jiaolong vessel to atmospheric one-man diving suits and autonomous underwater robots -- the latter would be exponentially beneficial in aiding aquanauts during danger-filled underwater mining missions.

The centre also appears to be keen on waterslides. Definitely one to watch.

By Liat Clark WIRE. UK. CO

Friday 15 June 2012

China sets new record submersible deepest seas dive

Chinese sub dives over 6,000 meters

ABOARD XIANGYANGHONG 09 - China's manned deep-sea submersible Jiaolong and three divers inside are rising from over 6,000 meters below the sea in the Mariana Trench after setting the country's dive record on Friday.
China's manned deep-sea submersible, Jiaolong, is unmoored from its mother ship before making its first dive in the Mariana Trench, as part of a bid to go to depths of up to 7,000 meters, June 15, 2012. [Photo/Xinhua]

The dive, which began at 9 am local time Friday (2300 GMT Thursday), is the first of a series of six scheduled ones.

The dive went smoothly and cost about 3 hours for the Jiaolong to reach the depth of 6,000 meters at 12 pm local time (0200GMT), which far surpassed the 5,188-meter record it made last July.

The three divers Ye Cong, Cui Weicheng and Yangbo inside the vessel wished China's Shenzhou-9 spacecraft launch a success from 6,055 meters below the sea.

The Shenzhou-9 manned spacecraft Thursday completed its final full-system drill before its planned launch in mid-June.

The Jiaolong threw ballast iron and began to rise at 12:44 pm local time (0244 GMT).

So far, the three drivers and the Jiaolong itself have been OK.

There was something wrong with the submersible's No 1 communication system, but the No 2 set is working soundly to guarantee the connection between the vessel and Xiangyanghong 09, its mother ship.

The rise is expected to last three hours and the on-scene dive headquarter will timely release the diving information.

The Jiaolong, depending on local weather and sea conditions, will try another five dives, deeper and deeper, in the coming days. The fifth and sixth are scheduled to challenge the depth of 7,000 meters.

The six dives, each of which may last eight to 12 hours, will test various functions and performances of the manned submersible at great depths.

Experts say, for safety, sea dives can only be conducted in daylight under no-more-than-four-class wind and no-more-than-three-class wave.

The Xiangyanghong 09 ship reached the designated dive zone in Mariana Trench on Monday morning.

China's manned deep-sea submersible, Jiaolong, is hung up before making its first dive in the Mariana Trench, as part of a bid to go to depths of up to 7,000 meters, June 15, 2012. [Photo/Xinhua]

Submersible sets new China dive record 

The "Jiaolong" craft descended to a depth of 6,000 metres in the Mariana Trench in the western Pacific OceanEnlarge

File photo of the Chinese submersible "Jiaolong". The manned Chinese submersible on Friday set a new record for the country's deepest ever sea dive at 6,000 metres (19,685 feet), state media said.

A manned Chinese submersible set a new record for the country's deepest sea dive Friday, over 6,000 metres, showing Beijing's technological ambitions as it also readies for its first manned space docking.

The "Jiaolong" craft dived over 19,685 feet into the Mariana Trench in the western Pacific Ocean, the first in a series of six dives which will plumb depths of 7,000 metres, the official Xinhua news agency said.

The deep-sea dive push comes as China prepares to launch a spacecraft on Saturday to conduct its first manned space docking, as part of efforts to establish a permanent space station by 2020.

The submersible, which carried three men, reached around 6,500 metres with only a technical glitch in communications, state media said.

"In our first battle, we have already reached 6,500 metres. All of our tasks have been completed," chief commander Liu Feng told state television aboard the ship carrying the submersible.

He said a piece of communications equipment on the surface of the water failed, but the team switched to a back-up system and restored communications. He did not say whether contact was completely lost with the Jiaolong.

The same vessel -- named after a dragon from Chinese mythology -- reached 5,188 metres in a Pacific dive last July, the nation's previous record.

Friday's dive sparked outpourings of nationalism on the Internet and comparisons to the upcoming space launch.

"Three pilots will take the Jiaolong to attempt the 7,000-metre dive, while three astronauts will take the Shenzhou-9 to connect with the Heavenly Palace," a Shanghai based blogger wrote on his microblog.

"Up in the sky we can pluck the moon, down in the oceans we can catch the turtles," said the posting on Sina's microblog service, quoting a saying attributed to late Chinese leader Mao Zedong.

Experts say China intends to use the submersible for scientific research, such as collecting samples of undersea life and studying geological structures, as well as future development of mineral resources.

But one Chinese expert on Friday described the latest dives as an "experiment" for China and said future use of submersibles for scientific research faced obstacles, such as with stability and durability of the craft.

"Even after it reaches the 7,000-metre depth, it still remains a question whether it can achieve scientific purposes," Zhou Huaiyang, professor of the School of Ocean and Earth Sciences at Shanghai's Tongji University, told AFP.

Scientists say the oceans' floors contain rich deposits of potentially valuable minerals, but the extreme depths pose technical difficulties in harvesting them on a large scale.

 AFP
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Related post:
 China achieves double record-breaker: Sky-high and abyss-deep sea!
 

Saturday 2 June 2012

US naval fleet to shift towards Pacific by 2020

New strategy: The US plans to shift the bulk of its naval fleet to the Pacific, as Defence Minister Stephen Smith dismissed fears the move would stoke tensions with China. Picture: AP AP

SHIFTING FOCUS:While the US plans a ‘new strategic focus’ in Asia, China warned that now is not the time to ‘make waves’ in the South China Sea, which it claims

AFP, BEIJING and SINGAPORE

US fighter jets take off from the flight deck of the Nimitz-class USS George Washington for joint military exercises between the US and South Korea in the Sea of Japan (also known as the East Sea) on June 26, 2010.

China’s Xinhua news agency warned yesterday it was no time to “make waves” in the disputed South China Sea, after the US said it would shift the bulk of its naval fleet to the Pacific Ocean by 2020.

“It is advisable for some to refrain from muddying the waters and fishing therein,” said Xinhua, referring to the sea, which is part of the Pacific and the subject of overlapping territorial claims.

China claims the sea in full, and it is also claimed in whole or part by Taiwan, Brunei, Vietnam, Malaysia and the Philippines.

“As regards the South China Sea tensions, it is some other claimants, whether emboldened by the United States’ new posture or not, that sparked the fire and have been stoking the flames,” the agency said.

It was Beijing’s “genuine wish” to turn the South China Sea “into a sea of peace, friendship and cooperation,” Xinhua added.

The commentary was a reaction to US Secretary of Defense Leon Panetta telling a summit in Singapore yesterday that the US would shift the bulk of its naval fleet to the Pacific as part of a new strategic focus on Asia,

The decision to deploy more ships to the Pacific Ocean, along with expanding a network of military partnerships, was part of a “steady, deliberate” effort to bolster the US role in an area deemed vital to the US’ future, he said.

He insisted the switch in strategy was not a challenge to China, saying both countries had a common interest in promoting security and trade in the region.

“By 2020, the navy will re-posture its forces from today’s roughly 50/50 percent split between the Pacific and the Atlantic to about a 60/40 split between those oceans,” Panetta said.

“That will include six aircraft carriers in this region, a majority of our cruisers, destroyers, littoral combat ships and submarines,” he added.

The US Navy currently has a fleet of 285 ships, with about half of those vessels deployed or assigned to the Pacific.

Although the total size of the overall fleet might decline in coming years depending on budget pressures, Pentagon officials said the number of US naval ships in the Pacific would rise in absolute terms.

The US also planned to expand military exercises in the Pacific and to conduct more port visits over a wider area extending to the Indian Ocean.

Panetta was speaking to mainly Asian defense officials and officers from 27 countries at the Shangri-la Dialogue, an annual summit organized by the London-based International Institute for Strategic Studies.

VIDEO: US EXPLAINS PACIFIC-FOCUSED MILITARY STRATEGY CCTV News - CNTV English



Unlike previous summits, China chose not to send a high-level delegation to the event, prompting speculation as to what lay behind the move.

Since US President Barack Obama unveiled plans in January to shift toward Asia, the Pentagon has offered up few details about how it intends to achieve that goal.

Yesterday’s announcement on the future of the US fleet provided the clearest evidence yet of a shift to Asia, and the speech appeared designed to reassure allies that Washington would back its much-publicized “pivot” to Asia with tangible action.

In his speech, Panetta said budget woes in Washington would not affect the plan to tilt towards Asia, which he said would take years to fully realize.

The US planned new investments in capabilities needed “to project power and operate in the Asia-Pacific,” including radar-evading fighter jets, a new long-distance bomber, electronic warfare and missile defenses, he said.

“But make no mistake — in a steady, deliberate and sustainable way — the United States military is rebalancing and is bringing an enhanced capability and development to this vital region,” he added.

Military commanders are revising doctrine to take into account new weapons that “could deny our forces access to key sea routes and lines of communication,” Panetta said.

Amid a growing US-China rivalry, US officials privately acknowledge the push for a larger military footprint is meant to reinforce US diplomacy when confronting Beijing’s assertive stance in the South China Sea.

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U.S. designs on South China Sea exposed!
China's warns US of Confrontation over South China Sea

Tuesday 6 December 2011

Prepare for combat, China’s Hu urges navy!



AFP
 
Chinese President Hu Jintao Tuesday urged the navy to prepare for military combat amid growing regional tensions over maritime disputes and a US campaign to assert itself as a Pacific power.

The navy should “accelerate its transformation and modernisation in a sturdy way, and make extended preparations for military combat in order to make greater contributions to safeguard national security,” he said.

Addressing the powerful Central Military Commission, Hu said: “Our work must closely encircle the main theme of national defence and military building.”

His remarks, which were posted on a statement on a government website, come amid growing US and regional concerns over China’s naval ambitions, particularly in the South China Sea.



Chinese President Hu Jintao on Tuesday urged the navy to prepare for military combat, amid growing regional tensions over maritime disputes and a US campaign to assert itself as a Pacific power.

The navy should "accelerate its transformation and modernisation in a sturdy way, and make extended preparations for military combat in order to make greater contributions to safeguard national security," he said.

Addressing the powerful Central Military Commission, Hu said: "Our work must closely encircle the main theme of national defence and military building."

His comments, which were posted in a statement on a government website, come as the United States and Beijing's neighbours have expressed concerns over its naval ambitions, particularly in the South China Sea.

Several Asian nations have competing claims over parts of the South China Sea, believed to encompass huge oil and gas reserves, while China claims it all. One-third of global seaborne trade passes through the region.



Vietnam and the Philippines have accused Chinese forces of increasing aggression there.

In a translation of Hu's comments, the official Xinhua news agency quoted the president as saying China's navy should "make extended preparations for warfare.

The Pentagon however downplayed Hu's speech, saying that Beijing had the right to develop its military, although it should do so transparently.

"They have a right to develop military capabilities and to plan, just as we do," said Pentagon spokesman George Little, but he added, "We have repeatedly called for transparency from the Chinese and that's part of the relationship we're continuing to build with the Chinese military."

"Nobody's looking for a scrap here," insisted another spokesman, Admiral John Kirby. "Certainly we wouldn't begrudge any other nation the opportunity, the right to develop naval forces to be ready.

"Our naval forces are ready and they'll stay ready."

State Department spokesman Mark Toner said: "We want to see stronger military-to-military ties with China and we want to see greater transparency. That helps answer questions we might have about Chinese intentions."

Hu's announcement comes in the wake of trips to Asia by several senior US officials, including President Barack Obama, Defense Secretary Leon Panetta and Secretary of State Hillary Clinton.

US undersecretary of defence Michelle Flournoy is due to meet in Beijing with her Chinese counterparts on Wednesday for military-to-military talks.

Chinese Premier Wen Jiabao last month warned against interference by "external forces" in regional territorial disputes including those in the South China Sea.

And China said late last month it would conduct naval exercises in the Pacific Ocean, after Obama, who has dubbed himself America's first Pacific president, said the US would deploy up to 2,500 Marines to Australia.

China's People's Liberation Army, the largest military in the world, is primarily a land force, but its navy is playing an increasingly important role as Beijing grows more assertive about its territorial claims.

Earlier this year, the Pentagon warned that Beijing was increasingly focused on its naval power and had invested in high-tech weaponry that would extend its reach in the Pacific and beyond.

China's first aircraft carrier began its second sea trial last week after undergoing refurbishments and testing, the government said.

The 300-metre (990-foot) ship, a refitted former Soviet carrier, underwent five days of trials in August that sparked international concern about China's widening naval reach.

Beijing only confirmed this year that it was revamping the old Soviet ship and has repeatedly insisted that the carrier poses no threat to its neighbours and will be used mainly for training and research purposes.

But the August sea trials were met with concern from regional powers including Japan and the United States, which called on Beijing to explain why it needs an aircraft carrier.

China, which publicly announced around 50 separate naval exercises in the seas off its coast over the past two years -- usually after the event -- says its military is only focused on defending the country's territory.

Chinese-Navy

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Friday 23 September 2011

NASA satellite falls back to Earth !





Dead satellite likely fell into Pacific Ocean--maybe

By: William Harwood, CNET

NASA's decommissioned 6.3-ton Upper Atmosphere Research Satellite, out of gas and out of control after two decades in space, plunged back into the atmosphere early Saturday, heating up, breaking apart, and presumably showering chunks of debris along a 500-mile-long Pacific Ocean impact zone.
Maybe.

U.S. Strategic Command radar tracking indicated re-entry would occur around 12:16 a.m. EDT (GMT-4) Saturday as the satellite was descending across the Pacific Ocean on a southwest-to-northeast trajectory approaching Canada's west coast. If re-entry occurred on or before the predicted time, any wreckage that survived atmospheric heating almost certainly fell into the Pacific Ocean.

NASA's derelict Upper Atmosphere Research Satellite fell to Earth Saturday, presumably into the Pacific Ocean west of Canada. But it's not yet a sure thing.

"Because we don't know where the re-entry point actually was, we don't know where the debris field might be," said Nicholas Johnson, chief orbital debris scientist at NASA's Johnson Space Center.

"If the re-entry point was at the (predicted time) of 04:16 GMT, then all that debris wound up in the Pacific Ocean. If the re-entry point occurred earlier than that, practically the entire pass before 04:16...is over water. So the only way debris could have probably reached land would be if the re-entry occurred after 04:16."

Johnson said amateur satellite watchers in the U.S. northwest and the Canadian southwest were "looking to observe UARS as it came over. Every one of those attempts came up negative. That would suggest that the re-entry did, in fact, occur before it reached the North American coast, which, again, would mean most of this debris fell into the Pacific."

But it's not yet certain and it's equally possible a delayed re-entry resulted in debris falling somewhere in northern Canada or elsewhere along the trajectory.

"We may never know," Johnson told reporters in an afternoon teleconference.

The centerpiece of a $750 million mission, the Upper Atmosphere Research satellite was launched from the shuttle Discovery at 12:23 a.m. EDT (GMT-4) on Sept. 15, 1991. The solar-powered satellite studied a wide variety of atmospheric phenomena, including the depletion of Earth's ozone layer 15 to 30 miles up.

The long-lived satellite was decommissioned in 2005, and one side of its orbit was lowered using the last of its fuel to hasten re-entry and minimize the chances of orbital collisions that could produce even more orbital debris. No more fuel was available for maneuvering and the satellite's re-entry was "uncontrolled."

As with all satellites in low-Earth orbit, UARS was a victim of atmospheric drag, the slow but steady reduction in velocity, and thus altitude, caused by flying through the tenuous extreme upper atmosphere at some five miles per second.

UARS' final trajectory as it neared the discernible atmosphere proved difficult to predict. The descent slowed somewhat Friday, presumably because the spacecraft's orientation changed. As the day wore on, the predicted impact time slipped from Friday afternoon to early Saturday.

Johnson said falling satellites typically begin breaking up at an altitude of around 50 miles. In the case of UARS, computer analysis indicated about 26 pieces of debris would survive to reach the surface, spread out along a 500-mile-long down-range footprint. Johnson said the heel of the footprint, the area where the lightest debris might fall, is typically 300 miles or so beyond the breakup point.

But so far, "we've got no reports of anyone seeing anything that we believe are credible," Johnson said.

Johnson told reporters last week he expected most of the satellite to burn up as it slammed into the dense lower atmosphere at more than 17,000 mph. But computer software used to analyze possible re-entry outcomes predicted 26 pieces of debris would survive to impact the surface, the largest weighing some 330 pounds. Impact velocities were expected to range from 30 mph to 240 mph.

"We looked at those 26 pieces and how big they are, and we've looked at the fact they can hit anywhere in the world between 57 north and 57 south, and we looked at what the population density of the world is," he said. "Numerically, it comes out to a chance of 1 in 3,200 that one person anywhere in the world might be struck by a piece of debris. Those are obviously very, very low odds that anybody's going to be impacted by this debris."

For comparison, some 42.5 tons of wreckage from the shuttle Columbia hit the ground in a footprint stretching from central Texas to Louisiana when the orbiter broke apart during re-entry in 2003. No one on the ground was injured and no significant property damage was reported.

The UARS satellite is deployed into orbit in 1992.
An astronaut picture of the UARS satellite being deployed in 1991.
Photograph courtesy NASA

An astronaut picture of the UARS satellite being deployed in 1991.
Photograph courtesy NASA

Defying predictions one last time, NASA's doomed UARS satellite dove through Earth's atmosphere late last night over the North Pacific Ocean, off the U.S. West Coast, the space agency says. (Also see "Space Debris: Five Unexpected Objects That Fell to Earth.")

As recently as Friday morning, U.S. officials had forecast that the Upper Atmosphere Research Satellite, or UARS, would fall out of the sky in the late afternoon or early evening Friday, eastern time.
(See "NASA Satellite Falling Faster Due to Solar Activity.")

But the satellite shifted position as it tumbled toward the planet, forcing scientists to throw out their earlier time estimates.

NASA said early Saturday that UARS fell out of orbit sometime between 11:23 p.m. and 1:09 a.m. ET.
Amateur satellite trackers in places such as San Antonio, Texas, and northern Minnesota reported catching glimpses of UARS as it made its final, doomed circles around Earth.

Though the spacecraft plummeted over the Pacific, it's still not clear exactly where debris from the satellite has landed. Pieces of the satellite will be strung along a debris "footprint" stretching 500 miles (800 kilometers).

So far there are "no reports of any damage or injury," NASA said via Twitter close to midday Saturday.
Satellite Pieces Not For Sale

UARS, which weighed more than six tons, was lofted into orbit by the space shuttle Discovery in 1991. The craft recorded data on Earth's atmosphere until it was switched off in 2005.

Some 1,100 pounds (500 kilograms) of debris from the satellite were projected to survive the superheated descent through the atmosphere. The biggest intact piece, NASA said, would probably be a 300-pound (140-kilogram) chunk of the spacecraft's structure.

NASA warned the curious not to touch any pieces of the spacecraft that may have made it to the ground, because of the risk of sharp edges.

The space agency also tried to head off sales of UARS remnants on Internet auction sites such as eBay.
"Any pieces of UARS found are still the property of the country that made it," NASA warned via Twitter this morning. "You'll have to give 'em back to U.S."
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Lifeless satellite falls back to Earth

(China Daily)




Lifeless satellite falls back to Earth
Junk left from colliding satellites floats through space in this computer-generated image. NASA confirmed that two communication satellites from the United States and Russia collided 800 kilometers above northern Siberia on Sept 10. [Provided to China Daily]
NASA assures public that there is little chance of getting hit by debris

WASHINGTON - Fragments from an old 6-ton NASA satellite hurtled toward Earth on Friday, while the exact site of the crash-landing remained a mystery into the final hours.

The US space agency has stressed that the risk is "extremely small" that any of the 26 chunks that are expected to survive the fiery re-entry into Earth's atmosphere will hit one of the planet's seven billion people a one in 3,200 chance.


"Re-entry is possible sometime during the afternoon or early evening of Sept 23, Eastern Daylight Time," NASA said on its website on Thursday night.

That would be early morning Saturday Beijing time.

"It is still too early to predict the time and location of re-entry with any more certainty, but predictions will become more refined in the next 24 hours."

The influence of solar flares and the tumbling motion of the satellite make narrowing down the landing a particularly difficult task, experts said as the Internet lit up with rumors of where and when it would fall.

The US Department of Defense and NASA were busy tracking the debris and keeping all federal disaster agencies informed, a NASA spokeswoman said.

The Federal Aviation Administration issued a notice on Thursday to pilots and flight crews of the potential hazard and urged them to "report any observed falling space debris to the appropriate (air traffic control) facility and include position, altitude, time and direction of debris observed," CNN said.

The satellite was launched in 1991 and was designed to provide data for better understanding Earth's upper atmosphere and the effects of natural and human interactions on the atmosphere. The satellite was deactivated in 2005 as it ran out of fuel and was left orbiting Earth.



Orbital debris experts say space junk of this size from broken-down satellites and spent rockets tends to fall back to Earth about once a year, though this is the biggest NASA satellite to fall in three decades.

NASA's Skylab crashed into western Australia in 1979.

The surviving chunks of the tour-bus sized satellite will include titanium fuel tanks, beryllium housing and stainless steel batteries and wheel rims. The parts may weigh as little as one kg or as much as 158 kg, NASA said.

Orbital debris scientists say the pieces will fall somewhere between 57 north latitude and 57 south latitude, which covers most of the populated world.

The debris field is expected to span 800 square kilometers.

Pang Zhihao, a researcher from the Chinese Research Institute of Space Technology, told Xinhua that the crash could have been avoided had the satellite been put into a higher orbit, or manipulated to drop in the South Pacific when it had abundant fuel.

Lifeless satellite falls back to Earth
Pang said most spacecraft will incinerate upon re-entering Earth's atmosphere, and the debris will mostly likely fall into the ocean or hit an uninhabited area.

NASA has also said that in 50 years of space exploration no one has ever been confirmed injured by falling space junk.

The craft contains no fuel and so is not expected to explode on impact.

"No consideration ever was given to shooting it down," NASA spokeswoman Beth Dickey said.
NASA has warned anyone who comes across what they believe may be debris not to touch it but to contact authorities for assistance.

Space law professor Frans von der Dunk from the University of Nebraska-Lincoln's College of Law told AFP that the United States will likely have to pay damages to any country where the debris falls.

"The damage to be compensated is essentially without limit," von der Dunk said, referring to the 1972 Liability Convention to which the United States is one of 80 signatories.

"Damage here concerns 'loss of life, personal injury or other impairment of health; or loss of or damage to property of States or of persons, natural or juridical, or property of international intergovernmental organizations,'" he said, reading from the agreement.

However, the issue could get thornier if the debris causes damage in a country that is not part of the convention.

"The number of countries so far theoretically at risk is rather large, so there may be an issue if damage would be caused to a state not being party to the Liability Convention," he said.

AFP-Xinhua

Huge Tumbling Satellite Could Fall to Earth Over US Tonight or Saturday, NASA Says

 "The satellite's orientation or configuration apparently has changed, and that is now slowing its descent," NASA officials wrote in a morning status update today. "There is a low probability any debris that survives re-entry will land in the United States, but the possibility cannot be discounted because of this changing rate of descent." [Complete coverage of NASA's falling satellite]

NASA expects about 26 large pieces of the UARS spacecraft to survive re-entry through Earth's atmosphere and reach the planet's surface. The biggest piece should weigh about 300 pounds. The spacecraft is the largest NASA satellite to fall from space uncontrolled since 1979. [6 Biggest Spacecraft to Fall Uncontrolled From Space]

NASA officials have said the the chances that a piece of UARS debris hits and injures one of the nearly 7 billion people on the planet are about 1 in 3,200. However, the personal odds of you being struck by UARS satellite debris are actually about 1 in several trillion, NASA officials have said.

As of 10:30 a.m. EDT (1430 GMT) today, the UARS satellite was flying in an orbit of about 100 miles by 105 miles (160 kilometers by 170 km), and dropping.  NASA launched the UARS satellite in 1991 to study Earth's ozone layer and upper atmosphere. The satellite was decommissioned in 2005.

"Re-entry is expected late Friday, Sept. 23, or early Saturday, Sept. 24, Eastern Daylight Time," NASA officials wrote. "Solar activity is no longer the major factor in the satellite's rate of descent."

The sun has had an extremely active week, one that has included several solar flares. High solar activity can cause the Earth's atmosphere to heat and expand, which can increase drag on a low-flying satellite like UARS, making it fall faster.
Get a snapshot view of NASA's Upper Atmosphere Research Satellite (UARS), which will fall to Earth in 2011, in this SPACE.com infographic.
Get a snapshot view of NASA's Upper Atmosphere Research Satellite (UARS), which will fall to Earth in 2011, in this SPACE.com infographic.
CREDIT: Karl Tate, SPACE.com Contributor
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