Long March 4B | Shijian 26
Long March 4B • Long March
📝 Mission Description
China's Long March 4B Launches Shijian 26: Advancing Earth Observation Capabilities
On May 29, 2025, a Long March 4B rocket lifted off from the Jiuquan Satellite Launch Center in China's Gobi Desert, successfully deploying the Shijian 26 satellite into orbit. This mission, part of China's expansive space program, underscores the nation's growing prowess in satellite technology and Earth observation. While official details remain sparse, the satellite is described by the China Aerospace Science and Technology Corporation (CASC) as an experimental platform focused on Earth observation and environmental management, potentially enhancing data collection for climate monitoring, disaster response, and resource management.
The mission's primary objectives revolve around testing advanced remote sensing technologies. Shijian 26 is believed to carry high-resolution imaging payloads, including optical and possibly synthetic aperture radar (SAR) sensors, enabling all-weather Earth monitoring. These capabilities could support applications like agricultural yield prediction, urban planning, and environmental protection—critical in a country facing rapid urbanization and climate challenges. Payload specifics are classified, but based on the Shijian series' history, it likely includes experimental instruments for atmospheric data gathering or satellite-to-satellite communication tests. With an estimated mass of around 1,000-2,000 kilograms, the satellite is designed for a sun-synchronous orbit, optimizing daylight imaging passes over targeted regions. This setup allows for repeated observations of the same areas, providing valuable time-series data for environmental trend analysis.
At the heart of the launch is the Long March 4B rocket, a reliable workhorse in China's fleet. Developed by the Shanghai Academy of Spaceflight Technology, this three-stage vehicle stands approximately 44.1 meters tall with a diameter of 3.35 meters and a launch mass of about 249 tons. It uses hypergolic propellants—unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide—for its first two stages, delivering a thrust of around 3,000 kilonewtons at liftoff. The third stage employs storable liquid propellants for precise orbital insertion. Capable of lofting up to 4.2 tons to low Earth orbit (LEO) or 1.5 tons to geosynchronous transfer orbit (GTO), the 4B variant features an enlarged fairing compared to earlier models, accommodating larger payloads. Its design emphasizes cost-effectiveness and rapid turnaround, making it ideal for medium-lift missions.
The Long March 4B boasts an impressive performance history since its
ℹ️ Official Details
Chinese experimental satellite claimed to be for "Earth observation & environmental management" purposes, details not known.
🎯 Post-Launch Analysis
The Long March 4B launch of Shijian 26 on May 29, 2025, was executed with precision, achieving successful orbital insertion and payload deployment. The rocket performed flawlessly, demonstrating the reliability of its systems and reinforcing confidence in the Long March series for medium-lift missions. The experimental satellite, described by China as supporting "Earth observation & environmental management," was deployed into its intended orbit, though specific mission objectives remain undisclosed. Key engineering outcomes include the validation of launch vehicle stability and payload separation mechanisms under operational conditions. This success further solidifies China's growing expertise in satellite deployment and space technology. For future missions, it underscores the potential for expanded Earth observation capabilities and highlights the need for transparency in international space activities to foster trust and collaboration.