China CGST announces 100Gbps Space-Ground laser transmission system

The race to establish Satellite-to-Ground Laser Communications is heating up. Recently, China achieved a major milestone, which puts it ahead of Elon Musk’s Starlink system, at least that is unil Musk releases his Gen 3 satellite systems.

The nation successfully attained a 100 gigabit per second data transmission rate in satellite-to-ground laser communication. This unprecedented speed — ten times faster than their previous record — opens doors to a new era of space-based communications technologies.

Chang Guang Satellite Technology, the company behind the Jilin-1 constellation, accomplished this feat. Jilin-1 is reported to be the “world’s largest sub-meter commercial remote sensing satellite network.” As per South China Morning Post (SCMP), the data was transmitted between a mobile truck-based ground station and one of the 117 constellation satellites in Earth’s orbit.

Interestingly, this advancement gives Chang Guang Satellite a lead over Starlink.

“Musk’s Starlink has revealed its laser inter-satellite communication system but hasn’t deployed laser satellite-to-ground communication yet. We think they might have the technology, but we’ve already started large-scale deployment,” Wang Hanghang, the company’s head of laser communication ground station technology, told SCMP.

Hanghang added: “We plan to deploy these laser communication units across all satellites in the Jilin-1 constellation to improve their efficiency, with a goal of networking 300 satellites by 2027.”

With technological advancement, satellites are getting smarter and better at capturing detailed information. However, sending all that data back to Earth using traditional methods is becoming a bottleneck.

Satellite communication, especially with lasers, is a more efficient and affordable solution.  For this reason, Chang Guang Company decided to focus on laser communication technology in 2020.

Chang Guang developed a compact laser communication terminal — roughly the size of a backpack — capable of transmitting data both between satellites and from space back to Earth.

This advanced terminal was incorporated into the payload of a satellite (designated Jilin-1 02A02) launched in June 2023.

Since the ground station is mounted on a vehicle, it can be moved to avoid bad weather and turbulence, making the data transmission more reliable.

Multiple receiving stations will be established across China to improve remote sensing image data acquisition efficiency.

However, the achievement was not straightforward. For this achievement, the team overcame various technical hurdles, including atmospheric disturbances, the rapid movement of the satellite, and maintaining precise laser beam alignment. In the last few years, the company made rapid progress in developing high-speed laser communication technologies — both for space-to-ground and inter-satellite data transmission.

For instance, the system had previously achieved a 10Gbps data transfer rate from space to Earth in October 2023. SCMP stated this latest achievement of 100Gbps transmission rate is said to be equivalent to transmitting ten full-length movies within a “single second.”

This development in satellite-to-ground laser communication will significantly enhance China’s space capabilities. It will pave the way for improved satellite infrastructure, including navigation, 6G internet, and remote sensing.