Long March 4B

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 manufactured by the China Aerospace Science and Technology Corporation (CASC), the main contractor for the Chinese space program. CASC is a state-owned entity officially established in July 1999 as part of a Chinese government reform drive, with earlier incarnations of the program dating back to 1956. The rocket belongs to the Long March family, whose maiden flight took place on 24 April 1970, and more specifically to the Long March 4 sub-family. The Long March 4B itself made its maiden flight on 10 May 1999. It remains an active vehicle in the Chinese launch fleet.

The Long March 4B is a three-stage rocket used mostly to place satellites into low Earth and sun-synchronous orbits. It is launched from Launch Complex 1 at the Taiyuan Satellite Launch Center. The vehicle stands 44.1 metres tall with a diameter of 3.35 metres and has a launch mass of 249 tonnes. Its payload capacity is rated at 4,200 kilograms to low Earth orbit and 1,500 kilograms to geostationary transfer orbit. The rocket is not reusable: no landing attempts, successful or otherwise, are recorded for it in the available data.

According to SpaceRocket's database, the Long March 4B has flown 57 times since its debut, with 56 successful launches and one failure. This corresponds to a success rate of roughly 98 percent across more than two decades of operations, a record that places it among the more reliable members of the Long March family. The vehicle's single recorded failure stands against a long run of successful missions, and its continued active status indicates that it remains in operational service. As an expendable launcher, the Long March 4B does not attempt booster recovery, and its flight history therefore reflects a conventional launch profile focused on delivering satellites to low Earth and sun-synchronous orbits from Taiyuan. Overall, the numbers describe a mature, dependable workhorse of the Chinese orbital launch fleet, with a flight record spanning from 1999 to the present and only one unsuccessful mission to date.