Changzheng 3 Family
The Changzheng 3 (or Long March 3 in its English translation) family of space launch vehicles (SLV) was designed to deliver spacecraft to the geostationary transfer orbit (GTO), where the satellite then uses its own apogee kick stage to manoeuvre to its intended position on geostationary Earth orbit (GEO). The launch vehicle is launched from the Xichang Satellite Launch Centre (XSLC).
The basic configuration of the Changzheng 3 is a three-stage, liquid-propellant rocket, with four stabilising fins attached to the lower end of the first stage. The launcher was derived from the two-stage Dongfeng 5 intercontinental ballistic missile, but added with a third-stage burning the LOX/LH2 liquid propellant. The Changzheng 3B was added with four strap-on boosters, while the Changzheng 3C was added with two boosters. The spacecraft is housed inside a payload fairing at the top of the launcher.
In 1978, CALT was tasked with the development of a new launch vehicle to launch the PRC’s first geostationary communication satellite Dongfanghong 2 (DFH-2). CALT was in charge of the overall design of the launch vehicle as well as the third-stage of the launcher, while SAST was responsible for the development of the first and second stage.
The maiden flight of the Changzheng 3 took place on 29 January 1984 to send the first DFH-2 experimental communications satellite into the orbit. However, the third-stage of the launcher failed to restart in order to move the satellite from the parking orbit to the GTO. As a result, the satellite was placed into an elliptical orbit and was unusable. A careful analysis of the failure was made using the telemetry data and the cause of the malfunction was identified as an abnormal mixture ratio in the gas generator for the third-stage.
After some modifications on its third-stage, the Changzheng 3 resumed its flight three months later and carried out six successful launches consecutively between April 1984 and April 1990, including PRC’s first commercial launch of a foreign communications satellite (AsiaSat 1).
On 28 December 1991, a Changzheng 3 launcher carrying the domestic ChinaSat 4 (ZhongXing 4) communications satellite failed, again due to the third-stage malfunction, leaving the payload with an apogee of only 2,450km instead of nearly 36,000km as required.
The Changzheng 3 returned to service in July 1994, carrying out another five GEO missions successfully between 21 July 1994 and 25 June 2000, before it was finally retired and replaced by the improved Changzheng 3A.
Variants
Last update: 28 Aug 2011