China Aerospace Science and Technology Corp, the nation's dominant space contractor, conducted the debut flight of its Long March 12B carrier rocket on Monday afternoon.

According to the State-owned conglomerate, commonly abbreviated as CASC, the 24-story-tall rocket blasted off at 4:40 pm from a newly built service tower at the Jiuquan Satellite Launch Center in the Inner Mongolia autonomous region.

After a short flight, the rocket successfully entered its preset orbit and deployed its payloads — the 10th batch of Spacesail Constellation communication satellites.

The launch marked China's 37th space mission this year and the 647th flight of the Long March rocket family.

Designed and built by the China Aerospace Science and Technology Commercial Launch Vehicle Group, a CASC subsidiary based in Shanghai, the new rocket stands about 72 meters tall and 4.37 meters in diameter, and features a two-stage configuration.

Powered by 10 YF-102 series engines fueled by liquid oxygen and kerosene, the Long March 12B can generate a liftoff thrust of about 800 metric tons and carry at least 20 tons of payloads into low-Earth orbit. It is currently China's most powerful single-body rocket.

Research and development of the new rocket began in September 2024. Its design was approved in March 2025, after which engineers started building a prototype.

Liang Yanqian, a rocket designer at the China Aerospace Science and Technology Commercial Launch Vehicle Group, said engineers adopted several innovative technologies, including high-performance pintle thrust chambers and lightweight turbopumps. These components form a highly compact propulsion system that contributes to the rocket's outstanding overall performance, he said.

Engineers also reduced the rocket's weight through a streamlined design. In addition, they adopted an efficient propellant management scheme, integrated aft sections and large-diameter fuel tanks to improve flight efficiency, according to Liang.

He added that the rocket's flight-control software can autonomously detect and respond to in-flight malfunctions, helping ensure a high mission success rate.

In the near future, engineers will conduct flight tests aimed at recovering the rocket's first-stage booster. If successful, a reusable version of the Long March 12B will enter service, Liang said.

Following Monday's launch, more than 160 satellites have been sent into space for the Spacesail Constellation.

Previously known as the G60 network, the Spacesail Constellation is designed to provide high-speed, secure and reliable broadband internet services worldwide. According to Spacesail, the network is expected to comprise more than 10,000 satellites operating in low-Earth orbit by the end of 2030.

Experts said that compared with satellites operating in higher orbits, low-Earth-orbit satellites offer lower latency and broader coverage, particularly in plateau regions, making them better suited for space-based internet networks.