China has set a new milestone in satellite-to-ground laser communications, achieving a peak data transmission speed of 120 Gbps in a real-world operational experiment. The breakthrough, led by the Aerospace Information Research Institute (AIR) under the Chinese Academy of Sciences, pushes high-speed space data transmission beyond the 100 Gbps mark and signals major progress for the future of space-based internet, Earth observation, and rapid data delivery from orbit.
What makes this record especially notable is how it was achieved. Rather than upgrading hardware or launching a new satellite, the team doubled performance by reconfiguring satellite software while the spacecraft was already in orbit. In other words, the jump from 60 Gbps to 120 Gbps came without any physical changes to the AIRSAT-02 satellite, demonstrating how much untapped potential can be unlocked through smarter in-orbit optimization of existing laser communication payloads.
The experiment was carried out using a self-developed laser ground station featuring a 500-millimeter aperture. The station is located on the Pamir Plateau in China’s Xinjiang Uygur Autonomous Region, a high-altitude site well-suited for optical communications because of its atmospheric conditions. From there, researchers established a laser link directly with the AIRSAT-02 satellite and validated the system under practical testing conditions.
Results from the test underscore that this wasn’t just a one-off speed spike, but a stable and usable connection. The satellite and ground station were able to acquire the link within seconds, with a reported success rate above 93%. The system also maintained continuous communication for as long as 108 seconds, and in that window moved an impressive 12.656 terabits of data.
This achievement also continues a rapid progression in China’s laser communications capabilities. The same research team previously demonstrated 10 Gbps in 2023, then increased that to 60 Gbps in 2025, before reaching today’s 120 Gbps peak. Each step forward becomes harder than the last, as higher throughput demands tighter precision, improved parallelization, stronger stability, and better handling of how data is packaged and transmitted through the optical link.
Li Yalin, a senior engineer at AIR and technical lead for the project, described the leap in terms of escalating complexity: earlier speeds were like moving traffic across a simple single-lane bridge, while 120 Gbps is closer to operating a multi-lane highway—requiring fast setup and efficient, parallel “traffic flow” to keep data moving at extreme rates.
As satellites collect ever-growing volumes of information—especially from high-resolution imaging, environmental monitoring, mapping, and scientific sensors—downlink bandwidth becomes a bottleneck. Demonstrations like this show how laser communications can relieve that pressure, enabling more data to reach the ground faster, with stronger scalability for future constellations and next-generation space services.
