Ceres-1S | Tianqi 16-18 & 20

China's Ceres-1S Rocket Boosts IoT Constellation with Tianqi Satellite Launch

On May 19, 2025, China's burgeoning commercial space sector marked another milestone with the successful launch of the Ceres-1S rocket from the Jiuquan Satellite Launch Center. Carrying four small satellites—Tianqi 16, 17, 18, and 20—the mission aimed to expand a low Earth orbit (LEO) constellation dedicated to Internet of Things (IoT) communications. This deployment underscores the growing role of private enterprises in advancing global connectivity, particularly in remote and underserved regions.

The primary objective of the Tianqi mission series is to build a robust satellite network for IoT applications, enabling real-time data transmission for industries such as agriculture, environmental monitoring, logistics, and disaster management. Operated by Beijing-based Guodian Gaoke, the Tianqi constellation leverages narrowband communication technology to support low-power, wide-area networks. Each of the four satellites launched weighs approximately 50 kilograms and is designed for a lifespan of several years in LEO, orbiting at altitudes between 500 and 600 kilometers. Their payload capabilities include advanced transceivers that handle data rates up to 10 kilobits per second, facilitating seamless integration with ground-based IoT devices. This setup allows for efficient, cost-effective global coverage, reducing reliance on terrestrial infrastructure and addressing challenges like signal latency in remote areas. By adding these satellites, the constellation now approaches two dozen operational units, enhancing redundancy and coverage density to support an estimated millions of connected devices worldwide.

At the heart of this mission is the Ceres-1S rocket, a sea-launched variant of the Ceres-1 developed by Galactic Energy, one of China's leading private aerospace firms. The rocket stands about 20 meters tall with a diameter of 1.4 meters and a launch mass of around 31 tons. It employs a four-stage solid-propellant design, which offers simplicity, rapid deployment, and lower costs compared to liquid-fueled alternatives. The first three stages provide the thrust for ascent, while the fourth stage ensures precise orbital insertion. With a payload capacity of up to 300 kilograms to a 500-kilometer sun-synchronous orbit, the Ceres-1S is optimized for small satellite missions, making it an attractive option for commercial clients. Its sea-launch capability, demonstrated from a mobile platform in the Yellow Sea, adds flexibility by mitigating range safety concerns and enabling launches from equatorial latitudes for better orbital efficiency.