Long March 5

📷 中国新闻社 / Wikimedia Commons (CC BY 3.0)

The Long March 5 — Chang Zheng 5, or CZ-5 — is China’s most powerful operational rocket, built by the China Academy of Launch Vehicle Technology. It stands about 57 m tall, weighs roughly 869,000 kg at liftoff, and comes in two versions: the two-stage CZ-5 for high orbits and deep space, and the CZ-5B, which trades the second stage for a huge fairing to haul 25,000 kg into low Earth orbit.

Nearly every headline Chinese space achievement of the 2020s rode on it: the modules of the Tiangong space station, the Chang’e lunar sample-return missions, and Tianwen-1, the country’s first Mars orbiter and rover.

Development History

China began developing the Long March 5 in the 2000s as a clean break from its older rockets, which burned toxic, storable propellants. Engineers created two new engines from scratch — the kerosene-oxygen YF-100 for the boosters and the hydrogen-oxygen YF-77 for the core — and built a brand-new coastal spaceport, Wenchang on Hainan Island, because the 5 m diameter core stages travel by ship and are too wide for China’s railway tunnels.

The maiden flight on 3 November 2016 succeeded, but the second launch in July 2017 failed when a first-stage YF-77 turbopump broke down, and the payload never reached orbit. The failure grounded the rocket for two and a half years and pushed back China’s lunar and space-station plans; a redesigned engine flew a successful return-to-flight mission in December 2019.

Since then the rocket has flown a steady string of flagship missions, and by mid-2025 the family had logged more than a dozen launches.

Design & Capabilities

Four strap-on boosters, each with two YF-100 kerosene engines, deliver most of the roughly 10,600 kN of liftoff thrust, while the hydrogen-fueled 5 m core with its two YF-77s burns far longer. The CZ-5’s second stage uses two restartable YF-75D hydrogen engines for precise high-orbit insertions, delivering about 14,000 kg to geostationary transfer orbit — and it has flung probes toward the Moon and Mars at Earth-escape speeds of roughly 40,000 km/h. An optional Yuanzheng-2 space tug can ride on top for direct injections into very high orbits.

The CZ-5B variant deletes the second stage entirely: the core pushes station-module-sized payloads of up to 25,000 kg straight into low orbit. That design drew international criticism, because after several launches the huge empty core stage reentered the atmosphere uncontrolled, scattering debris unpredictably — a practice most space agencies design their rockets to avoid.

Notable Missions

In July 2020 a Long March 5 launched Tianwen-1, which put China’s first orbiter around Mars and delivered the Zhurong rover to the surface in 2021, making China the second country to operate a rover on Mars. That November, Chang’e 5 rode to the Moon and brought back 1.7 kg of lunar samples — the first returned by anyone since 1976 — and Chang’e 6 repeated the feat in 2024 from the Moon’s far side, a world first.

The CZ-5B, meanwhile, built the Tiangong station, launching the Tianhe core module in April 2021 and the Wentian and Mengtian laboratory modules in 2022. In late 2024 it also began lofting the first batches of China’s planned Guowang internet megaconstellation.

Frequently Asked Questions

Why does Long March 5 launch from an island?

Wenchang on Hainan Island sits at about 19 degrees north, where Earth’s rotation gives a bigger free speed boost than China’s older inland sites. Just as important, the 5 m core stages arrive by ship, since they cannot fit through railway tunnels, and spent stages fall harmlessly into the sea instead of over land.

What happened on its second flight?

In July 2017 a turbopump in one of the core stage’s YF-77 hydrogen engines failed, and the rocket fell short of orbit. The failure grounded the Long March 5 for about two and a half years, delaying the Chang’e 5 sample return and the space station, until a redesigned engine flew successfully in December 2019.

What is the difference between CZ-5 and CZ-5B?

The CZ-5 is a two-stage rocket for geostationary transfer, lunar and interplanetary missions, sending about 14,000 kg toward geostationary orbit. The CZ-5B drops the second stage and adds a giant fairing so the core can push about 25,000 kg — a space station module — directly into low Earth orbit.

How does it compare with other heavy rockets?

Its 25,000 kg to low orbit sits in the same class as Europe’s Ariane 64, well below Falcon Heavy’s 63,800 kg. Within China nothing operational matches it, and it remains the essential rocket for the country’s biggest missions until the crew-rated Long March 10 and super-heavy Long March 9 arrive.