Long March 3B

Long March 3B
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Name	Long March 3B
Manufacturer	China Academy of Launch Vehicle Technology
Country of origin	People's Republic of China
Height	54.8 m
Diameter	3.35 m
Mass	456,000 kg
Status	Active
First flight	1996-02-14

Long March 3B The Long March 3B is a heavy-lift orbital launch vehicle developed and produced by the China Academy of Launch Vehicle Technology for deployment of geostationary satellites, interplanetary probes, and crewed and uncrewed payloads from Chinese spaceports. It serves missions for organizations including the China National Space Administration, China Satellite Communications, and commercial operators, launching from sites such as Xichang Satellite Launch Center and, more recently, Wenchang Satellite Launch Center. The family has been central to the Chinese space program expansion, supporting applications for Beidou Navigation Satellite System, communications constellations, and scientific probes.

Overview

The launcher is part of the broader Long March (rocket family) lineage developed after experience with vehicles like the Long March 2F and Long March 3A, incorporating a cryogenic third-stage design derived from technology used on missions such as Chang'e 1 and later applied to probes including Chang'e 3 and Chang'e 4. Key stakeholders include the China Aerospace Science and Technology Corporation and industrial subcontractors across provinces such as Sichuan and Jiangxi. Typical payloads target geostationary orbit, geosynchronous transfer orbit, and trans-lunar injection trajectories supporting programs like China Lunar Exploration Program and commercial telecommunication deployments by firms akin to AsiaSat and ChinaSat affiliates.

Design and Specifications

The vehicle is a three-stage core with four strap-on boosters; propulsion integrates hypergolic storable propellants on the first and second stages and a cryogenic hydrogen/oxygen third stage based on the YF-75 engine family. Structural components employ alloys and manufacturing techniques developed in institutes such as Beijing Institute of Aeronautical Materials and test facilities like the China Academy of Space Technology thermal vacuum chambers. Avionics and guidance draw on heritage from projects including Shenzhou and satellite bus developments at CAST Research Center. Telemetry and tracking support has involved assets such as the Xi'an Satellite Control Center and international cooperation with agencies analogous to Arianespace for commercial market comparisons.

Development and Operational History

Development began as an evolution of earlier rockets responding to demand from operators like China Telecom and research institutes including National Astronomical Observatories, Chinese Academy of Sciences. First flight occurred in 1996 with payloads from organizations comparable to China Satellite Communications. Over its operational history, the vehicle has been employed for missions linked to Beidou, communications satellites for companies similar to APSTAR, and scientific payloads associated with institutions like the National Space Science Center. Program management involved entities such as the Ministry of Aerospace Industry (historical) and contemporary agencies including CASIC-linked suppliers.

Launch Vehicle Variants

Variants expanded the baseline into improved configurations: an enhanced version with uprated boosters and improved third-stage engines reflecting work in institutes such as the Shanghai Academy of Spaceflight Technology; a commercialized variant tailored for partnerships with operators like China Satcom; and experimental adaptations for heavier interplanetary payloads paralleling mission profiles used by Tianwen-1. Competing and complementary families in the national portfolio include vehicles like Long March 5 and Long March 7, influencing upgrade paths and manifest allocation across centers such as Jiuquan Satellite Launch Center.

Launches and Notable Missions

Notable missions include placement of major communications satellites commissioned by companies like ChinaSat and regional operators similar to APSTAR, launches supporting the Beidou Navigation Satellite System, and deployments for scientific and exploratory projects akin to the Chang'e series and probes comparable to Tianwen-1. Specific launches attracted international attention when failures impacted facilities and nearby infrastructure, invoking responses from agencies like the State Council and technical reviews involving teams from CALT and university laboratories such as those at Tsinghua University and Beihang University.

Reliability, Anomalies, and Investigations

The vehicle's reliability record includes a majority of successful missions alongside several high-profile anomalies that led to investigations by panels composed of experts from CAST, CALT, and research institutions including Chinese Academy of Sciences divisions. Failure analyses cited issues in areas investigated by laboratories at Harbin Institute of Technology and systems validated against standards used in international programs like International Telecommunication Union coordination for orbital slots. Resulting corrective actions encompassed manufacturing oversight changes, revised quality assurance practices informed by work at China Metrology Institute, and procedural updates analogous to reforms implemented after incidents involving other national launchers.

Upgrades and Future Enhancements

Planned and implemented upgrades have addressed propulsion improvements in the third stage, avionics modernization leveraging silicon and composite advances from institutes such as Institute of Microelectronics of the Chinese Academy of Sciences, and structural weight reductions informed by research at Northwestern Polytechnical University. Future enhancements aim to increase payload capacity to geostationary transfer orbit and support heavier probes resembling Tianwen-class missions, while coordination with commercial operators and projects like proposed satellite constellations echoes strategies used by entities such as SpaceX and OneWeb in international markets. Continued development aligns with national programs overseen by organizations such as the China National Space Administration and industrial partners including CASC subsidiaries.

Category:Chinese space launch vehicles