France’s Defense Ministry announced that its Defense Innovation Agency (AID) and Cailabs have achieved a groundbreaking high-speed optical satellite communication between a low-orbit nano-satellite and a commercial optical ground station.
Governments are increasingly interested in satellite laser communications as a means to enhance internet resilience against potential attacks, particularly those targeting subsea cables that currently handle most transatlantic internet traffic. Laser communications, both inter-satellite and satellite-to-ground, enable faster transmission of larger data volumes.
Optimal performance of laser satellite communication requires a network of multiple satellites exchanging data among themselves before transmitting it to Earth. An effective laser communication network necessitates dozens or even hundreds of satellites to achieve global coverage. The nano-satellite’s laser communication terminal, produced by French startup Unseenlabs, is a commercially available product. Numerous companies offer these terminals, which are required to be interoperable due to US Space Development Agency regulations.
Laser-based space communication presents several technical challenges. Unlike radio waves, laser light forms a narrow beam that must be precisely aimed at a ground-based receiver, such as a telescope, for successful data transmission. Despite laser light’s ability to travel vast distances in space, atmospheric effects and weather conditions can distort laser beams.
This distortion can lead to power loss in the beam, potentially resulting in data loss. The French experiment, launched in late 2023, involved the Keraunos satellite and aimed to test high-speed optical communications using Cailabs’ innovative technology. AID provided $6.1 million in funding for the Keraunos project, which also involved Unseenlabs. The team successfully established a stable laser link lasting several minutes, enabling them to track the low Earth orbit nano-satellite from the optical ground station and receive data transmitted from the satellite.
Optical links offer advantages over traditional radio links in terms of speed, discretion, and freedom from radio wave usage regulations. Although atmospheric turbulence can occasionally disrupt the optical link, the Keraunos satellite is capable of overcoming these disturbances to maintain optimal transmission quality.