Long March 3C/YZ-1 | Shiyan 29
Long March 3C/YZ-1 • Long March
📝 Mission Description
China's Long March 3C/YZ-1 Launches Shiyan 29 Satellite
On September 5, 2025, China marked another milestone in its ambitious space program with the successful launch of the Shiyan 29 satellite aboard a Long March 3C/YZ-1 rocket from the Xichang Satellite Launch Center in Sichuan Province. This mission, shrouded in some secrecy as is common with China's experimental payloads, underscores the nation's rapid advancements in space technology and its strategic positioning in global space exploration.
The primary objective of the Shiyan 29 mission, as officially stated by the China Aerospace Science and Technology Corporation (CASC), is "space environment detection." This vague descriptor aligns with the Shiyan series' focus on testing new technologies for monitoring cosmic phenomena, such as radiation levels, magnetic fields, and orbital debris. While exact details remain classified, analysts speculate that the satellite could incorporate advanced sensors for real-time data collection, potentially aiding in space weather forecasting or satellite constellation management. Payload capabilities likely include high-resolution imaging systems and environmental monitoring instruments, with a design emphasizing longevity in geostationary transfer orbit (GTO). Such satellites often serve dual purposes, blending civilian research with potential military applications like reconnaissance or signal intelligence, though no official confirmation exists. The mission's opacity reflects China's approach to space activities, where technological trials can inform broader programs like the BeiDou navigation system or future lunar explorations.
At the heart of the launch is the Long March 3C/YZ-1 rocket, a reliable workhorse in China's fleet. The Long March 3C is a three-stage launch vehicle derived from the earlier Long March 3A, enhanced for medium-lift capabilities. It stands approximately 55 meters tall with a diameter of 3.35 meters at its core stage. The first stage is powered by four YF-21C engines burning unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide, generating about 1,200 kilonewtons of thrust each. The second stage uses a single YF-24 engine, while the third stage employs a YF-75 cryogenic engine fueled by liquid hydrogen and oxygen, enabling precise orbital insertions. The YZ-1 upper stage, a key addition, provides additional propulsion for GTO missions, boosting payload capacity to around 3,800 kilograms. This configuration allows for a total liftoff mass of about 345 tons and a thrust-to-weight ratio optimized for equatorial launches from Xichang,
ℹ️ Official Details
Satellite officially named for "space environment detection" purposes, exact details unknown.
🎯 Post-Launch Analysis
The Long March 3C/YZ-1 mission, launching Shiyan 29 on September 05, 2025, achieved a successful orbital insertion and payload deployment. The rocket performed flawlessly during ascent, demonstrating reliable technical execution and precise trajectory control. The satellite, designated for "space environment detection," was deployed into its intended orbit, though specific mission objectives remain undisclosed. Engineering outcomes highlight the robustness of the Long March 3C/YZ-1 configuration, reinforcing confidence in its design for medium-lift missions. This success further validates China's consistent progress in space launch capabilities, ensuring operational reliability for future endeavors. The mission's outcome strengthens the foundation for subsequent Shiyan-series experiments, potentially advancing space environment monitoring technologies. It also underscores the adaptability of the Long March family, paving the way for more complex missions and international collaborations in the evolving space domain.