Long March 4B

Long March 4B
Name	Long March 4B
Manufacturer	China Academy of Launch Vehicle Technology
Country	People's Republic of China
Height	41.9 m
Diameter	3.35 m
Mass	250,000 kg
Status	Active
First	1999-05-10
Family	Long March

Long March 4B Long March 4B is a three-stage orbital launch vehicle developed by the China Academy of Launch Vehicle Technology for placing satellites into Sun-synchronous orbit and low Earth orbit. Derived from earlier members of the Long March family, the launcher has served civil, scientific, and meteorological programs and supported missions for actors such as the China National Space Administration, the State Bureau of Surveying and Mapping, and research institutes. Its operational role complements other Chinese vehicles used by programmes like Shenzhou, Chang'e, and Tiangong.

Overview

Long March 4B occupies a place within the Long March family alongside vehicles such as Long March 2F, Long March 3B, and Long March 5. Developed by the China Academy of Launch Vehicle Technology, the rocket enabled expanded capabilities for operators including the China National Space Administration, the Ministry of Science and Technology, and the National Remote Sensing Center. The launcher has been integrated into missions that support agencies such as the Chinese Academy of Sciences, the National Meteorological Center, and commercial entities collaborating with institutions like the China Aerospace Science and Industry Corporation and CAST. Long March 4B launches typically originate from sites used for polar and Sun-synchronous injections that figure in plans by regional authorities and international partners.

Design and Specifications

The three-stage design follows a liquid-propellant architecture with hypergolic propellants similar to configurations used by contemporaries in the Long March lineage. Structural and propulsion developments were overseen by CAAV, with key components procured and produced across supply chains involving companies like the China Aerospace Science and Technology Corporation and affiliated research centers of the Chinese Academy of Sciences. The vehicle's first and second stages employ kerosene/LOX and hypergolic systems in earlier family members, while the third stage provides precise orbital insertion for payloads such as remote sensing satellites developed by institutes like the National Satellite Meteorological Center and the Institute of Remote Sensing Applications. Guidance and avionics draw on technologies tested in programs associated with the China Academy of Space Technology and research from institutions including Tsinghua University and the Beijing Institute of Technology.

Launch History

The maiden flight occurred in 1999, marking an operational start that paralleled broader Chinese initiatives such as the BeiDou navigation buildup and the Fengyun meteorological series. Over subsequent years, Long March 4B supported campaigns for Earth observation constellations fielded by agencies like the National Remote Sensing Center and research projects tied to the Chinese Academy of Sciences. Launches have been scheduled and executed in coordination with provincial authorities at facilities administered by the China Aerospace Science and Technology Corporation and operational teams trained in procedures influenced by prior missions including those in the recoverable satellite and experimental payload programs. High-tempo periods corresponded with international collaborations and procurement of imaging assets from academic partners including Peking University and the Harbin Institute of Technology.

Payloads and Missions

Long March 4B has lofted a range of payloads such as meteorological satellites in the Fengyun series, remote sensing platforms for the Yaogan program, experimental microgravity payloads from universities, and technology demonstrators tied to the Chinese Academy of Sciences. Notable payload operators and stakeholders include the National Satellite Meteorological Center, the Chinese Academy of Sciences, the National Remote Sensing Center, and commercial entities contracting through the China Satellite Launch and Tracking Control General. Missions have supported projects affiliated with research institutions like the Institute of Remote Sensing Applications, the National Oceanic agencies of neighboring states in bilateral arrangements, and scientific collaborations with universities including Zhejiang University and Shanghai Jiao Tong University. Payload accommodation has enabled optical imagers, synthetic aperture radar modules, and smallsat clusters developed by teams at the Chinese Academy of Sciences and industrial partners.

Ground Infrastructure and Launch Sites

Long March 4B launches are conducted from Chinese launch complexes configured for polar and Sun-synchronous trajectories, notably sites that are part of the network used by the China National Space Administration and the China Aerospace Science and Technology Corporation. Facilities include launch pads with integrated processing and payload encapsulation infrastructure maintained by provincial and national organizations collaborating with contractors such as the China Aerospace Science and Industry Corporation. Launch operations draw on tracking and telemetry networks operated by the China Satellite Launch and Tracking Control General and use range assets co-developed with research centers including those at the Chinese Academy of Sciences and university partners providing instrumentation and analysis support.

Reliability and Anomalies

The vehicle has an operational record reflecting multiple successful insertions and a small number of anomalies that prompted investigations by CAAC-affiliated teams and technical review boards drawing expertise from the China Academy of Launch Vehicle Technology, the China Aerospace Science and Technology Corporation, and academic partners. Failure analyses have referenced telemetry, guidance units, stage separation events, and ground support procedures, with corrective measures informed by engineering groups at institutions such as the Beijing Institute of Technology and the Harbin Institute of Technology. Reliability metrics place the launcher among the stable members of the Long March family, supporting continued use for civil, scientific, and commercial missions coordinated by agencies including the China National Space Administration and the National Remote Sensing Center.

Category:Chinese rockets