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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.

WASHINGTON, July 15 (Xinhua) -- Coastal communities along the U. S. East Coast may be at risk to higher sea levels accompanied by more destructive storm surges in future El Nino years, according to a new study published Friday by the U.S. National Oceanic and Atmospheric Administration (NOAA).The study was prompted by an unusual number of destructive storm surges along the East Coast during the 2009-2010 El Nino winter.The study, led by Bill Sweet, from NOAA's Center for Operational Oceanographic Products and Services, examined water levels and storm surge events during the "cool season" of October to April for the past five decades at four sites representative of much of the East Coast: Boston, Atlantic City, Norfolk and Charleston.From 1961 to 2010, it was found that in strong El Nino years, these coastal areas experienced nearly three times the average number of storm surge events (defined as those of one foot or greater). The research also found that waters in those areas saw a third-of-a-foot elevation in mean sea level above predicted conditions."High-water events are already a concern for coastal communities. Studies like this may better prepare local officials who plan for or respond to conditions that may impact their communities," said Sweet. "For instance, city planners may consider reinforcing the primary dunes to mitigate for erosion at their beaches and protecting vulnerable structures like city docks by October during a strong El Nino year."El Nino conditions are characterized by unusually warm ocean temperatures in the Equatorial Pacific that normally peak during the Northern Hemisphere "cool season." They occur every three to five years with stronger events generally occurring every 10-15 years. El Nino conditions have important consequences for global weather patterns, and within the U.S., often cause wetter-than- average conditions and cooler-than-normal temperatures across much of the South.

WASHINGTON, July 15 (Xinhua) -- Researchers at Mount Sinai School of Medicine have found that grape seed polyphenols -- a natural antioxidant -- may help prevent the development or delay the progression of Alzheimer's disease.The research, led by Giulio Pasinetti, was published online Friday in the Journal of Alzheimer's Disease, which causes brain changes that gradually get worse.This is the first study to evaluate the ability of grape- derived polyphenols to prevent the generation of a specific form of amyloid (A) peptide, a substance in the brain long known to cause the neurotoxicity associated with Alzheimer's disease.In partnership with a team at the University of Minnesota, Pasinetti and collaborators administered grape seed polyphenolic extracts to mice genetically determined to develop memory deficits and A neurotoxins similar to those found in Alzheimer's disease. They found that the brain content of the A*56, a specific form of A previously implicated in the promotion of Alzheimer's disease memory loss, was substantially reduced after treatment.Previous studies suggest that increased consumption of grape- derived polyphenols, whose content, for example, is very high in red wine, may protect against cognitive decline in Alzheimer's. This new finding corroborates those theories."Since naturally occurring polyphenols are also generally commercially available as nutritional supplements and have negligible adverse events even after prolonged periods of treatment, this new finding holds significant promise as a preventive method or treatment, and is being tested in translational studies in Alzheimer's disease patients," said Pasinetti.In Alzheimer's disease, brain cells degenerate and die, causing a steady decline in memory and mental function.

BEIJING, June 28 (Xinhuanet) -- A truck-sized asteroid passed over the Atlantic Ocean within 7,500 miles of the Earth on Monday, according to NASA's Jet Propulsion Laboratory.The space rock, called asteroid 2011 MD, is the second space rock to zip extremely close to the Earth this year.The asteroid, with latest size estimates ranging from 16 to 66 feet (5 to 20 meters) wide, was discovered just last week on June 22, but there was never any risk of it impacting the Earth, NASA scientists said. That means asteroid 2011 MD would likely be too small to survive the fiery plunge through the Earth's atmosphere, let alone reach the surface, NASA scientists said. Asteroids this size can be expected to buzz Earth with close shaves about once every six years, they added.The space rock flew well below geosynchronous satellites, which orbit 22,236 miles (35,786 km) above the Earth, but well above the 220-mile (354-km) altitude of the International Space Station.There was little chance that the asteroid would hit a satellite because of the vastness of space and relatively small number of satellites, experts said.

WASHINGTON, July 27 (Xinhua) -- The solar-powered, Jupiter- bound Juno spacecraft was secured into place on top of its rocket Wednesday in preparation for launch next month, the U.S. National Aeronautics and Space Administration (NASA) announced.The launch period for Juno opens Aug. 5 and extends through Aug. 26. For an Aug. 5 liftoff, the launch window opens at 11:34 a.m. EDT (1534 GMT) and remains open through 12:43 EDT (1643 GMT).Juno will arrive at Jupiter in July 2016 and orbit its poles 33 times to learn more about the gas giant's interior, atmosphere and aurora."We're about to start our journey to Jupiter to unlock the secrets of the early solar system," said Scott Bolton, the mission 's principal investigator from the Southwest Research Institute in San Antonio. "After eight years of development, the spacecraft is ready for its important mission."