OrbitalHub

Telesat is positioning its Lightspeed low Earth orbit constellation as a critical component of defense communications networks, with a planned laser communications demonstration in 2027 that could validate the system for high-demand applications including missile defense. The Canadian satellite operator announced the strategy during the Satellite 2026 conference in Washington, D.C., highlighting changes to the system design aimed at military compatibility.

The company plans to launch the first two Lightspeed satellites in December 2026, with a laser communications relay demonstration scheduled for 2027 under a $30 million NASA contract awarded in 2022. The test will simulate a data relay scenario in orbit: one satellite will act as a mission spacecraft, the other as a relay node. A subsequent phase will involve a Planet Labs imaging satellite equipped with an optical terminal, which will send data through the Lightspeed system to a ground station.

Chuck Cynamon, president of Telesat Government Solutions, emphasized that the demonstration represents a proof point for the Pentagon’s growing interest in space-based data networks. “There’s a demand for hybrid architectures,” Cynamon stated, pointing to the Space Force’s development of what it calls a “space data network” intended to connect satellites, sensors, and weapons into a unified real-time architecture.

The Golden Dome missile defense initiative would depend on such networks as its core transport layer, routing data between sensors, command systems, and interceptors in near real time. Gen. Michael Guetlein, who leads Golden Dome, has indicated that funding for the space data network is increasing, with Cynamon noting that “there’s probably no limit on how much capability is going to be needed on orbit from a space data network.”

The company has modified its system design to align with military requirements, including adding military Ka-band frequencies aligned with the Pentagon’s existing wideband satcom systems. Each of the planned 198 Lightspeed satellites will carry four optical terminals supplied by Tesat-Spacecom, enabling high-speed links between spacecraft that can move large volumes of information with low latency while reducing exposure to jamming or interception.

The capacity pool model Telesat intends to offer the government would allow access to Lightspeed’s bandwidth and potentially optical connections without owning satellites. “We could also offer a pool of optical connections on a daily, weekly or monthly basis,” Cynamon explained, reflecting a broader shift toward hybrid architectures that blend military and commercial infrastructure.

Telesat expects to begin commercial service in 2028 after deploying the first 156 satellites, with launches contracted to SpaceX in batches of roughly 15 spacecraft. The company enters a competitive field dominated by SpaceX’s Starlink and Starshield, along with emerging systems such as Amazon LEO. Both competitors are pursuing defense business and deploying optical inter-satellite links.

One emerging demand driver is the concept of orbital data centers, which Cynamon noted could further increase pressure on satellite networks to expand capacity and move data more quickly between space and the ground. “I think it’s going to put pressure on the ability to have large pipes and land data quickly on the ground,” he observed.

Optical communications between satellites operate at frequencies far higher than traditional radio-frequency links, typically using near-infrared wavelengths around 1550 nanometers. This frequency choice offers several advantages for space-based communications, including narrower beam divergence that enables higher data rates while reducing interference between neighboring links.

The fundamental principle involves modulating a laser beam with data and directing it precisely at a receiving terminal, requiring extremely precise pointing and tracking systems. The transmitting terminal must aim its beam with accuracy measured in microradians, roughly equivalent to aligning two lasers pointed from opposite ends of a football field and having them meet at the 50-yard line.

Data rates for optical links can reach 10 gigabits per second or higher, compared to typical radio-frequency satellite links measured in megabits per second. This capacity advantage becomes particularly significant for applications involving large data volumes, such as high-resolution imagery or video from Earth observation satellites.

The laser links used in satellite constellations employ coherent detection, where the receiving terminal mixes the incoming optical signal with a locally generated laser to extract the data. This technique provides sensitivity improvements over direct detection methods, enabling links across distances of thousands of kilometers with minimal transmit power.

Atmospheric effects present challenges for optical links that radio frequencies avoid, including scattering by molecules and aerosols, absorption by water vapor, and turbulence that can cause beam wander and scintillation. For inter-satellite links above Earth’s atmosphere, these effects largely disappear, making optical communications most attractive for links between spacecraft rather than from space to ground.