China is expected to launch its unmanned spacecraft Shenzhou-8 at 5:58 a.m. Tuesday, carried by a modified Long March-2F rocket. Shenzhou-8 will make the country\'s first space docking when it rendezvous with the space lab module Tiangong-1, which was lifted into space at the end of September. The modified Long March-2F rocket, with a length of 58.3 meters, has a liftoff weight of 497 tonnes and a payload capacity of 8.13 tonnes. The updated rocket is more powerful than previous versions in terms of thrust. A Long March-2F rocket carried China\'s first unmanned spacecraft Shenzhou-1 into space on Nov. 20, 1999. On Oct. 15, 2003, a Long March-2F launched Shenzhou-5, China\'s first manned spaceflight. It has since launched Shenzhou-6 and Shenzhou-7 into orbit. The Long March-2F is one of the derivations of Long March-2, which also includes the Long March-2C, -2D and -2E. It is considered the most reliable and safest in China. The Long March-2 is a two-stage carrier rocket that is 31.17 meters long with a maximum diameter of 3.35 meters. It has a liftoff weight of 190 tonnes and is capable of sending a 1.8-tonne satellite into elliptical orbit. China started development of modern carrier rockets in 1956, and Long March rockets have become the main carriers for China\'s satellite launching. The Long March rockets currently fall into four categories, namely the Long March-1, Long March-2, Long March-3 and Long March-4. The Long March-1 is a three-stage carrier rocket that is used to launch small-sized satellite into LEO (Low Earth Orbit). With a length of 29.86 meters and maximum diameter of 2.25 meters, the 81.6-tonne Long March-1 has a liftoff thrust of 112 tonnes and is capable of sending a 300-kg satellite into a LEO of 440 km high. On April 24, 1970, China launched its first satellite, Dong Fang Hong 1, or \"the East is Red,\" into the Earth\'s orbit on a Long March-1 rocket, becoming the fifth nation to achieve independent launch capacity after the Soviet Union, the United States, France and Japan. The Long March-1D carrier rocket is a derivation of the Long March-1 and has been put into commercial use with its capacity of sending satellites into LEO. LONG MARCH-3 The Long March-3 is a three-stage carrier rocket that was developed in 1984 based on the Long March-2 series. The third stage of a Long March-3 rocket\'s flight is powered by liquid hydrogen (LH2) as the fuel and liquid oxygen (LOX) as the oxidizer. The rocket has a full length of 44.86 meters. Its first and second stages\' rockets have a diameter of 3.35 meters while its third stage rocket has a diameter of 2.25 meters. The Long March-3 has a liftoff mass of 204.88 tonnes and is capable of sending a 1.6-tonne satellite to the geosynchronous transfer orbit (GTO). The Long March-3 also has a range of derivations such as the Long March-3A, -3B and -3C.