The Long March 4C, also known as the Chang Zheng 4C, CZ-4C and LM-4C, previously designated Long March 4B-II, is a Chinese orbital launch vehicle. It is launched from the Jiuquan, Taiyuan, and Xichang Satellite Launch Centers, and consists of 3 stages. Long March 4C vehicles have been used to launch the Yaogan-1, Yaogan-3 synthetic-aperture radar (SAR) satellites and the Fengyun-3A polar orbiting meteorological satellite. On 15 December 2009, a Long March 4C was used to launch Yaogan-8.

Because it was still designated as Long March 4B-II at the time of its maiden flight, the first launch is often mistaken for a Long March 4B. The Long March 4C is derived from the Long March 4B, but features a restartable upper stage, and a larger payload fairing.

On 1 September 2016, the Long March 4C failed for reasons not yet known. A Long March 4C rocket blasted off from the Taiyuan Satellite Launch Center in Shanxi but failed to insert its payload, the Gaofen 10 satellite, into its designated orbit.

Stats

Height: 45.8 m (150 ft)

Diameter: 3.35 m (11.0 ft)

Mass: 250,000 kg (550,000 lb)

Stages: 3

Jiuquan Satellite Launch Center is a Chinese space vehicle launch facility (spaceport) located in the Gobi Desert, Inner Mongolia. It is part of the Dongfeng Aerospace City (Base 10). Although the facility is geographically located within Ejin Banner of Inner Mongolia's Alxa League, it is named after the nearest city, Jiuquan in Gansu Province. The launch center straddles both sides of the Ruo Shui river.

It was founded in 1958, the first of China's four spaceports. As with all Chinese launch facilities, it is remote and generally closed to foreigners.

Jiuquan Satellite Launch Center is usually used to launch vehicles into lower and medium orbits with large orbital inclination angles, as well as testing medium to long-range missiles. Its facilities are state of the art and provide support to every phase of a satellite launch campaign. The site includes the Technical Center, the Launch Complex, the Launch Control Center, the Mission Command and Control Center and various other logistical support systems.

The center covers 2800 km (1739.8 miles) and may have housing for as many as 20,000 people. The facilities and launch support equipment were likely modelled on Soviet counterparts and the Soviet Union likely provided technical support to Jiuquan.

The launch center has been the focus of many of China's ventures into space, including their first satellite Dong Fang Hong I in 1970, and their first crewed space mission, Shenzhou 5 on 15 October 2003. As of 2021, all Chinese crewed space flights, meaning all flights in the Shenzhou program including crewed flights to the Tiangong space station, have launched from Jiuquan.

In August 2016, China launched the first quantum communication satellite, the "Quantum Experiments at Space Scale", from the center.

In August 2018, Chinese private rocket manufacturing startups i-Space and OneSpace launched sub-orbital rockets from the center. On July 25, 2019, the first Chinese private orbital launch took place from Jiuquan as I-Space launched their Hyperbola-1 rocket.