Long March 3B

The Long March 3B is China's workhorse for geostationary orbit — the rocket that has built the country's communications satellite infrastructure, deployed the Beidou global navigation constellation, and launched China's most ambitious deep space missions. With more than 115 launches across its variants and a success rate exceeding 96 percent, it has earned its place as one of the most reliable heavy-lift rockets currently operating anywhere in the world.

The 3B designation marks a significant step up from its predecessors. The original Long March 3, introduced in 1984, was China's first cryogenic upper stage rocket but could only carry about 1,450 kilograms to GTO. The Long March 3A improved performance, and the 3B — with four large liquid-fueled strap-on boosters added around the core — more than tripled GTO capacity at the cost of significantly increased complexity. That complexity showed on the inaugural flight: on February 14, 1996, just 22 seconds after liftoff from Xichang, the rocket pitched over and plowed into a nearby hillside, killing an unknown number of people in a village — the exact death toll was never officially confirmed by China, with estimates ranging from 6 to more than 100. The accident prompted a comprehensive review of the vehicle's inertial measurement system, and the subsequent Long March 3B missions flew successfully.

The rocket's propellant combination reflects China's legacy approach to liquid-fueled rocketry. The first stage, second stage, and all four strap-on boosters burn unsymmetrical dimethylhydrazine and nitrogen tetroxide — the same toxic hypergolic combination used by the Soviet Proton and many other Cold War-era rockets. Only the third stage, which performs the critical injection burn into geostationary transfer orbit or beyond, uses liquid hydrogen and liquid oxygen, providing the high specific impulse needed for efficient high-energy trajectory insertion. The YF-75 engine that powers the third stage cryogenic system represents a mature Chinese cryogenic capability developed over decades.

The Enhanced variant — the 3B/E, introduced in 2007 with a stretched first stage, enlarged strap-on boosters, and a taller payload fairing — added approximately 400 kilograms of GTO capacity and became the primary operational configuration. The 3B/E has been the vehicle of choice for China's largest commercial communications satellites and most ambitious national missions.

The Beidou navigation constellation is the Long March 3B's most significant sustained program. China's answer to GPS, Galileo, and GLONASS, the Beidou system required dozens of launches to build — MEO, IGSO, and GEO satellites deployed across multiple orbital regimes over more than a decade. The Long March 3B carried the majority of the Beidou-3 global constellation satellites launched from 2018 onward, completing the system that now provides global navigation services and has become an alternative to GPS for Chinese military and commercial users worldwide.

For deep space, the Long March 3B has proven equally capable. It launched Chang'e 3 and its Yutu rover to the Moon in December 2013 — China's first successful lunar landing — and carried Chang'e 4 and Yutu-2 to the far side of the Moon in December 2018, the first far side landing by any spacecraft. The 3B/E variant launched Tianwen-2 in May 2025 on China's first asteroid sample return mission, placing the spacecraft on a trajectory to near-Earth asteroid Kamoʻoalewa that required the precise high-energy insertion the cryogenic third stage provides.

The Xichang Satellite Launch Center in Sichuan Province is the Long March 3B's exclusive home. Situated in a mountainous valley at approximately 1,825 meters elevation, Xichang's geography creates operational constraints — downrange safety corridors over populated terrain have been a persistent challenge, with spent stages and debris occasionally falling near villages — but its lower latitude compared to northern Chinese launch sites provides an inherent performance advantage for GTO missions.

The Long March 3B family continues to fly regularly as of 2026, averaging more than a dozen launches per year. It will remain China's primary vehicle for GTO missions and lunar deep space missions until the Long March 5 takes over for heavier payloads and the next-generation reusable launch vehicles under development by CASC and private Chinese companies begin operations.