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WASHINGTON, July 7 (Xinhua) -- Space shuttle Atlantis will soar into the sky Friday on NASA's 135th and final flight. Its scheduled return to Earth later this month will mark the end of NASA's 30-year space program.Since its onset with the launch of space shuttle Columbia, the program has been seen as a cheap, safe and reliable way for space exploration.Despite its great contributions to U.S. manned space flight, it has also left some grave and tragic lessons, making its termination inevitable.HIKING COSTSLaunched in 1972 by then President Richard Nixon, the shuttle program aimed to provide a new system of affordable space travel and proved to be NASA's most enduring project in its 50 years of existence.In 1981, shuttle Columbia made its first shuttle flight for two days. It was the ultimate hybrid and the first reusable spacecraft.Launched like a rocket and gliding back to Earth like an airplane, space shuttles not only can act as a space taxi to carry astronauts, but have the muscle of a long-distance trucker to haul heavy machinery.The spaceship boasts more than 3,500 subsystems and 2.5 million parts and is nine times faster than a speeding bullet as it climbs heavenward. That versatility, however, has translated into higher costs.NASA originally estimated the program would cost about 90 billion U.S. dollars. However, its actual cost stands at about 200 billion dollars, compared with the 151 billion dollars spent on Apollo which took Americans to the moon in 1969.In an article in Technology Review, John Logsdon, former head of the Space Policy Institute at George Washington University, drew a direct connection between the ravenous shuttle budget and the lack of other large advances in manned space flight."By operating the system for 30 years, with its high costs and high risk, rather than replacing it with a less expensive, less risky second-generation system, NASA compounded the original mistake of developing the most ambitious version of the vehicle," he wrote."The shuttle's cost has been an obstacle to NASA starting other major projects," he added.HIGH RISKIn terms of safety, the shuttles have never been as reliable as their designers had envisioned.On average, one out of every 67 flights ended up with fatal accidents. Based on the rate of deaths per million miles traveled, the space shuttle is 138 times riskier than a passenger jet.Seven astronauts onboard died when Challenger exploded about a minute after launch in 1986. Nearly two decades after the tragic blast, a new catastrophe descended when the shuttle Columbia disintegrated moments before landing in 2003, killing another seven spacemen.Again, the shuttle program was shelved for more than two years as NASA stepped up efforts to make it safer. But experts say the fundamental problem related to shuttles' safety cannot be solved due to their "birth defects.""It is in the nation's interest to replace the Shuttle as soon as possible," concluded the panel that investigated the 2003 Columbia accident.

BEIJING, June 27 (Xinhuanet) -- A "lean gene" that helps people keep slim was found closely related to diabetes and heart disease, according to a study pulished in Nature Genetics journal on Sunday.The scientists from Britain’s Medical Research Council Epidemiology Unit conducted the study.After comparing the genetic codes of more than 75,000 people, a gene called IRS1 was spotted as the decisive factor to lower the fat level in human body.But in further study, IRS1 was found putting people to a 20 percent higher risk of developing heart disease and type-2 diabetes.The study warned that people who appear slim and fit might be also at risk.But scientists suggest that the study results did not change the general message for most people."While this study pointed to genes as one factor in determining the risk of developing these conditions, it was important to remember that lifestyle factors like diet, exercise, cutting out smoking and maintaining a healthy weight also play a vital role in reducing the risk," said Ruth Loos, who led the study.

GUANGZHOU, Aug. 2 (Xinhua) -- China conducted a scientific survey of the southwest basin of the South China Sea around the end of July, the China Geological Survey (CGS) said on Tuesday.The expedition acquired a "high-quality integrative geographic profile" of the basin's 1,000-km-long survey line, which stretches from the region's Xisha Islands to the Nansha Islands, according to a press release from the CGS.The expedition allows scientists to study the evolution of tectonic activity in the South China Sea and predict disasters such as earthquakes and tsunamis, the CGS said.The survey is also of significance for countries around the South China Sea, as they will be able to use the data to enhance their ability to prevent and reduce the effects of disasters, it said.The survey lasted from June 13 to July 31 and was carried out by the Chinese research vessel Tanbao in collaboration with a French research unit. Recent typhoons prevented the researchers from surveying part of the region, therefore some data is yet to be supplied later, the CGS said.

CANBERRA, Sept. 23 (Xinhua) -- A genetic study on Friday found Aboriginal Australians are descended from the first people to leave Africa up to 75,000 years ago.Researchers from the University of Western Australia, Murdoch University and an international team analyzed genetic material of a 100-year-old West Australian Aboriginal man's hair, and found he was directly descended from a migration out of Africa into Asia.The study revealed that Australian Aboriginal ancestors split from the first modern human populations to leave Africa, between 64,000 and 75,000 years ago, at least 24,000 years before other human migrations.According to Dr. Joe Dortch, an archaeologist at the University of Western Australia, the discovery rewrites the history of the human species by confirming humans moved out of Africa in waves of migrations rather than in one single out-of-Africa diaspora.It also rewrites the story about how Aborigines arrived in Australia some 50,000 years ago."So far there are no [archaeological] sites that are over 50, 000 years old so it puts a time limit on that and focuses our future efforts," he said in a statement released on Friday.Dr. Dortch believes the finding will foster a sense of pride in modern Australian Aborigines."No-one else in the world can say 'I am descended from people who have been here 75,000 years'."Associate Professor Darren Curnoe, leader of the Human Evolutionary Biology Lab in the School of Biological, Earth & Environmental Sciences at the University of New South Wales, said the study powerfully confirms that Aboriginal Australians are one of the oldest living populations in the world, certainly the oldest outside of Africa."Australians are truly one of the world's great human populations and a very ancient one at that, with deep connections to the Australian continent and broader Asian region. About this now there can be no dispute," he told Xinhua in an email note.Meanwhile, Professor Alan Cooper, Director of the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide, said while this is a major step forward, the key unresolved question remains the unique story of Aboriginal history within Australia, such as what has happened in those 50,000 years of life in the harsh Australian environment."Unfortunately, the information from a single individual tells us very little about this fascinating, and critically important part of human history. Aborigines are one of the oldest continuous human populations outside Africa, as they note in the paper, and due to the geographic isolation and limited archaeological records remain one of the most mysterious chapters in human history," he told Xinhua on Friday.The study is published on Friday in the journal Science.Indigenous Australians are the original inhabitants of the Australian continent and nearby islands. They together make up more than 2.5 percent of Australia's population.

BEIJING, Sept. 5 (Xinhua) -- China and the World Bank are jointly researching ways to help rebalance the world's second largest economy and move toward a path of sustainable growth under the current challenging global economic situation, said World Bank Group President Robert B. Zoellick on Monday.A report, jointly being prepared by the World Bank, China's Ministry of Finance, and the Development Research Center of the State Council, will be released later this year to support China in identifying the many challenges and policy choices it will face in the next two decades, as the country seeks to avoid the so-called "middle-income trap," a stage of economic development that has slowed progress in many countries, Zoellick said.Regarding this autumn as "a sensitive time facing the world's major economies," Zoellick said many countries, including the United States, the European Union and Japan, were facing the similar fundamental challenge of restructuring for sustainable economic growth."Perhaps the challenge is more difficult for China as the country has already made remarkable progress, and thus it's not easy to persuade people to make a change," he said.Commenting in Beijing on a weekend workshop with senior Chinese officials and outside experts, Zoellick said there was agreement that China will have to rebalance its economy, improve the environment, reduce inequality and advance the quality of life for its people while at the same time maintaining rapid growth."In the near term, inflation is China's priority, as Premier Wen Jiabao mentioned," Zoellick said, adding that the Chinese government was moving in the right direction, though it was too early to have the problem solved.In next 10 years, however, Zoellick said he could not imagine China continuing to rely on exports for growth, especially when developed economies have had difficulties recovering.By shifting away from an over-dependence on export-led growth to a greater reliance on domestic demand and investment, China could benefit not only itself but the world economy, he said.As China's 12th Five-Year Plan has pointed the way forward with what needs to be done, Zoellick said the ongoing research will try to help with the "how."He said the report will cover issues such as how China can complete its transition to a market economy; how to promote open innovation; how to advance green development; how to deliver equality of opportunity and social security to citizens; how to strengthen the fiscal system, and how China can become a responsible stakeholder in the international system.During his stay in China, Zoellick also visited the country's wasteland-turned-grain-producing-base in the northeast, including a farm, a rice mill, an agricultural research center and a modern agricultural machinery park, and learned about how this land transformation had affected local people's lives.As the world population is expected to hit 9 billion by 2050, Zoellick said the World Bank has been urging G-20 countries to prioritize food issues."China feeds 20 percent of the world's population with less than 10 percent of the world's agricultural land and less than six percent of its water, so China could make a significant contribution to global food security," Zoellick said.