Behind China's tallest rocket: Long March-12B

China's Long March-12B carrier rocket made its maiden flight on Monday, marking a new step in the country's efforts to support large-scale commercial space missions and low-Earth-orbit satellite constellations.

Standing 72 meters tall and measuring 4.37 meters in diameter, the Long March-12B is currently the tallest newly developed Chinese rocket to complete a successful first launch. Equipped with nine engines at its base, the vehicle is designed to deliver high payload capacity while reducing launch costs.

One of the rocket's most notable achievements is the speed of its development. Engineers completed the entire process, from initial design studies to final product development, in just 21 months, setting a new record for the development cycle of a new Chinese launch vehicle.

Developers attribute the accelerated timeline largely to digital design technologies. The team built its own simulation platform from scratch, integrating every stage from design and analysis to virtual verification. The system enabled close collaboration across engineering disciplines and significantly improved the efficiency of design iterations.

Faster development, smarter design

The rocket also adopts a "three-horizontal" launch model: horizontal assembly, horizontal testing and horizontal transportation. Under this approach, most complex preparations are completed in the technical area before the rocket is transported to the launch pad, where it is erected, fueled and launched. The process is expected to improve launch efficiency and support a higher launch cadence.

Beyond speed, the Long March-12B incorporates a range of design features aimed at reducing weight, improving reliability and increasing performance.

Powered by nine liquid oxygen-kerosene engines, the rocket uses a propellant combination that is relatively clean and cost-effective. Kerosene can be stored at normal temperatures, simplifying fueling procedures and lowering operational costs at launch sites.

Built for satellite constellations and future reuse

The Long March-12B is primarily intended to support China's low-Earth orbit internet constellation projects. With a payload capacity in the 20-tonne class, the rocket can deploy up to 36 satellites into a single orbital plane in a single mission, helping accelerate the construction of large-scale satellite networks.

Engineers have also designed the rocket with future reusability in mind. While key recovery and reuse technologies are still under development, the vehicle's first-stage architecture has been planned to accommodate potential reusable operations.

For now, the priority remains rapidly building launch capacity to meet the growing demand for satellite constellation deployment. Economically viable rocket recovery and reuse will require further technological breakthroughs and gradual development in the years ahead.