WASHINGTON — Each of the satellites in the Pentagon’s planned mesh network of communications satellites could have as many as four laser links so they can talk to other satellites, airplanes, ships and ground stations.
Optical inter-satellite links are critical to the success of the Space Development Agency’s low Earth orbit constellation — known as Transport Layer — that will be used to route data traffic. Lasers provide much higher transmission data rates than traditional radio-frequency communications but are also far more expensive.
SDA recently awarded nearly $1.8 billion in contracts for 126 satellites for the Transport Layer. By some estimates, about $500 million of that total would be for optical terminals, said Michael Abad-Santos, senior vice president of business development and strategy at BridgeComm, a Denver-based optical communications startup.
The company developed a so-called “one-to-many” optical communications technology for point-to-multipoint transmissions. This technology could help reduce the cost of building constellations by requiring fewer terminals, Abad-Santos said.
SDA last month awarded BridgeComm and Space Micro a $1.7 million Small Business Innovation Research contract to demonstrate the technology over the next two years. Space Micro, owned by Voyager Space, in January won a separate U.S. Air Force SBIR contract to develop an optical terminal to connect satellites with military aircraft.
BridgeComm first demonstrated point to multipoint optical communications in 2019 in a project with Boeing and has since continued to mature the technology, Abad-Santos said.
One-to-many connectivity is enabled by a device called managed optical communications array, or MOCA. “This is essentially the optical head and what is really unique about it is that it’s extremely modular,” he said. The MOCA aperture could make it possible for an optical inter-satellite link to talk to multiple other satellites.
“In traditional laser comms now everything is point to point, it’s a one-to-one relationship,” said Abad-Santos. “With MOCA, one optical inter satellite link can talk to 40 different satellites.”
SDA wants to further investigate how to apply this technology, he said. “This really allows the SDA and other satellite operators to potentially reduce the costs of the overall system architecture because they no longer need multiple gimbaled systems to talk in a one-to-one relationship.”
If the cost of the nodes comes down, this opens up opportunities to implement different network architectures that allow for different levels of service, Abad-Santos explained.
“You can have a gold tier, a silver tier and a bronze tier,” he said. “For those customers who want extremely low latency and high throughput you put them in the gold tier, and they are routed through the network in the most efficient way possible. For those customers that are less concerned about latency, you can put them in a lower tier at a lower cost and their traffic can be routed in the most economic way.”