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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.

SAN FRANCISCO, Sept. 9 (Xinhua) -- AOL's chief executive officer (CEO) Tim Armstrong has reached out to Yahoo for talks of a merger of the two companies, U.S. media reported on Friday.Armstrong is discussing options for a combination aimed at strengthening the two Internet companies, Bloomberg quoted two people who are familiar with the matter as saying.The report said that the AOL CEO had been interested in a merger with Yahoo last year but was rejected while Carol Bartz served as Yahoo CEO, who was ousted by Yahoo's board on Tuesday.Reconsidering the option after Bartz's departure, Armstrong has talked with private equity firms and investment bankers from Allen & Co. working with Yahoo.Under one scenario being considered, Yahoo would acquire AOL and Armstrong would become CEO of the combined company, said the source.Both Yahoo and AOL are suffering from declining revenues, struggling to compete against companies like Google and Facebook. Some analysts said that the merger could not provide a long-term solution to the problems the two companies face after they failed to keep up with Internet trends.

GENEVA, Sept. 26 (Xinhua) -- Two million people worldwide are estimated to die from air pollution each year, the Geneva based World Health Organization (WHO) said in its air quality report published on Monday.According to data collected by the WHO from nearly 1,100 cities across 91 countries, elevated level of fine particle pollution, which could cause heart diseases, lung cancer, asthma and acute lower reparatory infections, are common across many urban areas, with some cities registering fine particle pollution levels 15 times as much as the WHO guidelines.For both developed and developing countries, the biggest contributors to urban outdoor air pollution include motor transport, small-scale manufacturers and other industries, burning of biomass and coal for cooking and heating, as well as coal-fired power plants.Residential wood and coal burning for space heating is said to be an important contributor to air pollution, especially in rural areas during colder months, the WHO report said.

ULAN BATOR, Aug. 2 (Xinhua) -- The Mongolian government has confirmed equine influenza, a disease that mainly affects horses, broke out in 14 provinces.The government's news office announced the confirmation Tuesday after suspected cases were recently discovered in 18 provinces of the country, where horses still play a key role.According to a Mongolian government report, Mongolian Vice Premier M. Enkhbold called a state emergency situation committee meeting on Monday to respond to the epidemic.Millions of horses will need to be vaccinated, given cases of the disease have been discovered in all but three provinces -- Bayan-Ulgii, Zavkhan and Umnugobi.Equine influenza usually broke out in spring and fall, said an official of the Mongolian veterinarian and breeding bureau. He urged vaccination to be carried out as soon as possible.Mongolia has experienced several equine influenza outbreaks in the past few decades. Outbreaks in Khovd province in 2007 and 2008 caused huge losses to the local livestock industry.Animal husbandry is a dominant factor in the agriculture sector of Mongolia, which has more than 40 million livestock, 2 million of which are horses.