美国发射最大绝密间谍卫星

　　According to the Space.com on November 22, the giant booster - a Delta Four Heavy rocket - blasted off at 5:58 pm from the Cape Canaveral Air Force Base in Florida carrying a new spy satellite NROL-32 for the US's National Reconnaissance Office into orbit on November 21.

　　NRO director Bruce Carlson said that the rocket would launch "with the largest satellite in the world on it." However, the exact purpose of the new spy satellite NROL-32 is secret。

　　For comparison, in July 2009 a satellite called TerreStar-One - touted as previous largest commercial satellite ever built– launched into space on July 7 in 2009. TerreStar-One is a 6, 9 kg satellite。

　　The Delta Four Heavy rocket is the US' biggest unmanned rocket currently and has two million pounds(about 0.91 million kg) of thrust, making it the most powerful liquid- fueled booster available currently. A Delta Four Heavy rocket stands 235 feet tall and is actually made up of three boosters。

　　The rocket made its first flight in 2004 and is capable of launching payloads of up to 24 tons into low-Earth orbit and 11 tons toward the geosynchronous orbits used by communications satellites。

　　In his address last month, Carlson said that the current plan for NRO satellite missions "is the most aggressive launch campaign that the National Reconnaissance Office has had in 20 years, almost a quarter of a century."