美国“阿特兰蒂斯”号航天飞机于美国东部时间11日下午2时左右从佛罗里达州肯尼迪航天中心发射升空，机上7名宇航员将对哈勃太空望远镜进行最后一次维护。

　　The U.S. space shuttle Atlantis lifted off Monday with seven-member crew onboard from Kennedy Space Center in Florida, on a mission to upgrade the 19-year-old Hubble Space Telescope for the last time.

　　The blastoff occurred at 2:01 p.m. EDT (1801 GMT). It is NASA's second space shuttle flight in 2009 and the 30th flight for Atlantis.

　　The seven astronauts are commander Scott Altman, shuttle pilot Gregory C. Johnson and mission specialists Michael Good, Megan McArthur, John Grunsfeld, Michael Massimino and Andrew Feustel.

　　According to NASA TV, about two minutes and five seconds after liftoff, the twin solid rocket boosters assisting Atlantis' launch into space have separated as planned from the shuttle's external tank. The reusable boosters will fall back toward the Atlantic Ocean, where they will land under parachutes and be retrieved by recovery ships. They are equipped with cameras to record the performance of Atlantis' external tank and any foam loss seen during its ascent.

　　Atlantis is expected to reach Hubble on Wednesday. Its 11-day mission is the final shuttle flight to Hubble.

　　The seven-member crew will enhance the observatory and ensure cutting-edge science. The mission will put in place advanced technology that improves the telescope's discovery power by 10 to 70 times. Five spacewalks are planned to install new instruments and thermal blankets, repair two existing instruments, refurbish subsystems and replace gyroscopes, batteries and a unit that stores and transmits science data to Earth. The result will be six working, complementary science instruments with new capabilities, and an extended operational lifespan through at least 2014.

　　When Atlantis was on its way to Hubble, space shuttle Endeavour was prepared as a backup vehicle for Atlantis. Endeavour will also be launched if in the unlikely event that it's needed for a rescue flight.

　　That's because Atlantis' 11-day mission comes with a higher risk than usual. Atlantis will be flying in an unusually high orbit for a space shuttle -- 350 miles up. Space is more littered there with spacecraft parts, and the odds of a catastrophic strike are greater.

　　If Atlantis is irreparably damaged during flight, its crew won't be able to reach the safe haven of the International Space Station to seek refuge for the months required to ready an unprepared shuttle for a rescue. Hubble flies higher than the space station (about 350 miles up, while the station sits at 220 miles) and in a different orbital inclination -- or tilt with respect to Earth's equator.