TH 2 (Tianhui-2 = "Sky drawing") is a pair of Chinese cartography and Earth observation satellites.
The Long March 4B (Chinese: 长征四号乙火箭), also known as the Chang Zheng 4B, CZ-4B and LM-4B is a Chinese orbital carrier rocket. Launched from Launch Complex 1 at the Taiyuan Satellite Launch Center, it is a 3-stage rocket, used mostly to place satellites into low Earth and sun synchronous orbits.
The China Aerospace Science and Technology Corporation (CASC) is the main contractor for the Chinese space program. It is state-owned and has a number of subordinate entities which design, develop and manufacture a range of spacecraft, launch vehicles, strategic and tactical missile systems, and ground equipment. It was officially established in July 1999 as part of a Chinese government reform drive, having previously been one part of the former China Aerospace Corporation. Various incarnations of the program date back to 1956.INFO WIKI
China has launched a Long March/Chang Zheng-4B from the Taiyuan Satellite Launch Center at 22:32 UTC on August 18 carrying the second group of Tianhui 2 satellites into orbit.
China launched a Long March 4B rocket Wednesday carrying two Tianhui radar mapping satellites into orbit more than 300 miles in altitude.