Space-Based Laser Links Are Taking Center Stage

Today’s satellites collect more data than can be efficiently transmitted via traditional radio-frequency methods. As governments and companies build constellations with hundreds or even thousands of spacecraft, the use of optical communications technology using laser links is proliferating just as widely.

This is a turning point in the optical cross-link world—thanks in large part to SpaceX’s Starlink satellite constellation and to key investments by the U.S. Space Force and other governments.

• Space-based optical communications capabilities have moved beyond the research stage
• The global market is expected to reach $6.7 billion by 2033

A number of constellations will come online in the next 2-3 years, using laser links to connect and transmit data between satellites.

By 2027, the Space Development Agency’s (SDA) proliferated low-Earth-orbit (LEO) constellation could have 300-500 satellites in its transport layer, supporting 24/7 global communications, and more than 100 in its missile tracking layer. On the commercial side, Telesat’s planned Lightspeed LEO constellation will start with a base layer of 156 satellites and work up to 198, with launches beginning in late 2027.

The European Union’s IRIS2 is slated to include 264 communications satellites, with full service ready by late 2027. Munich-based Rivada Space Networks plans to deploy its 600-satellite Outernet by the same year to build a private space network for government and enterprise customers.

Multiple mega-constellations—with more than 1,000 spacecraft—are either planned or being deployed. Starlink counts 7,122 satellites in LEO as of March 21, according to data compiled by astronomer and astrophysicist Jonathan McDowell. Its initial layer is expected to hold 12,000.

Amazon has launched two satellites to date for its Kuiper constellation, which will eventually include more than 3,000 spacecraft. The next Kuiper launches are expected to begin imminently, officials said March 11 at the Satellite Conference & Exhibition in Washington.

With these constellations and more on the horizon, the laser cross-link industry is undergoing massive expansion. Prime contractors are investing in companies producing the optical communications terminals (OCT) that transmit and receive data. These providers—such as Germany’s Mynaric and Tesat-Spacecom, Ireland’s Mbryonics, and the U.S. Skyloom and Space Micro—are supplying terminals to a variety of commercial and government customers. A February report by market research company Astute Analytica projects the global space-based laser communication market could reach $6.7 billion by 2033.

The Defense Department ran the Transformational Satellite Communications System program in 2003-09, seeking to provide high-data-rate military satellite communications via radio-frequency (RF) and laser cross-links. The program was canceled under the fiscal 2010 budget request, with $1.5 billion spent on the design studies.

That effort never meaningfully matured in part because the Pentagon’s risk tolerance is much lower than that of a company, Telesat Government Solutions President Charles Cynamon told Aviation Week at the Satellite show.

A retired U.S. Air Force colonel, Cynamon headed the advanced concepts group in the service’s military satcom office in 2009-12. The U.S. military “kept running up to the precipice” of developing optical cross-links, but “never quite got there,” he said.

The technology seems to be moving “beyond the lab, beyond the research stage and out into the field,” said Jim Hooper, senior vice president of Cailabs US. The Rennes, France-based company is building space-to-ground optical communications terminals, including fixed sites and transportable systems, with a goal of delivering 50 fixed systems per year.

Laser-based communication offers a wealth of benefits over traditional RF, which is constrained by limited available bandwidth, signal attenuation and interference. It is also highly regulated, with limited spectrum allocation and licensing requirements. Optical communications offers specific benefits to the U.S. military, as the narrower beam leaves a much smaller footprint for a terminal to receive data, limiting an adversary’s ability to intercept the signal.

Downloading 1 TB of data can take 4 hr. via X-band, 14 min. at 10 Gbps via optical communications and less than 2 min. at 100 Gbps optical, according to data provided by Cailabs.

But there are limitations to its universal adoption, such as the atmospheric effects of clouds or rain while using laser links to bring data from space back to Earth. Pointing, acquisition and tracking—or the process by which two OCTs point at one another, make contact via laser link and track one another to keep the link intact to transmit data—is another challenge. The amount of “jitter” or disturbance to the signal caused by mechanical vibrations or atmospheric turbulence can also hinder communication.

Cross-link technology will not make the need for RF communication go away, particularly for space-to-ground data transport, Hooper said. Instead, merging the two capabilities by using RF as a backup and having ground stations dispersed across the globe offers significant capability and security to both government and commercial customers, he says.

The Defense Department is including laser-link technology in a number of current demonstrations and new space-based programs of record.

DARPA is in the final phase of a program to create a new laser terminal that would be fully reconfigurable and capable of working with both commercial and government constellations. The Space-Based Adaptive Communications Node (Space-BACN) is scheduled to have a full interoperability demonstration this year that will inform transition plans, Space-BACN Program Manager Greg Kuperman says.

The SDA has invested more than $10 billion to date in its marquee proliferated LEO satellite architecture, which is completely enabled by optical communication links, and developed its own OCT standard defining technical specifications for terminals to interconnect as part of the Proliferated Warfighter Space Architecture (PWSA).

The agency selected a data rate of 2.5 Gbps, in part to encourage a variety of vendors to participate in the PWSA, but also because Pentagon encryption requirements do not support higher data rates, according to a February Government Accountability Office (GAO) report.

In 2023-24, the SDA launched 27 satellites to prove out certain OCT capabilities under the Tranche 0 demonstration effort. The agency is building upon those tests as it fields over 150 satellites in the first operational layer, known as Tranche 1 and due to launch this year.

So far, the SDA has demonstrated space-to-space cross-link connections and data transmission with OCTs built by the same company in the same orbital plane with two separate vendors, York Space Systems and SpaceX. It has also demonstrated space-to-ground laser data links with SpaceX.

The SDA’s work with the PWSA has encouraged a rapidly expanding market for optical communications terminal providers—and lengthy supply chain delays. The agency has contracted with nine unique prime contractors to develop spacecraft for Tranches 0, 1 and 2. At least four different OCT developers are subcontractors across those nine prime contractors, per the GAO.

Initial launches for Tranche 0 were nearly 1.5 years behind the SDA’s planned schedule. The upcoming Tranche 1 launches are suffering similar delays after the massive uptick in spacecraft units for Tranche 1 caused snags in the terminal’s supply chains. Mynaric, which has a U.S. subsidiary based in Hawthorne, California, shared in 2024 that it had struggled to ramp up production of its hardware, in part due to shortages of key second-tier components. Rocket Lab, an SDA prime, announced March 11 that it planned to acquire a majority stake in Mynaric for an initial $75 million, contingent upon a restructuring process.

Meanwhile, the U.S. Space Systems Command (SSC) is developing its own government standard, known as SIS-002, to support higher data rates—up to 20 Gbps—to orbits beyond LEO. That standard would support the command’s $100 million Enterprise Space Terminal program, under which Blue Origin, CACI International, General Atomics and Viasat won contracts in 2024 to develop OCT prototypes.

SSC is working on a different cross-link program than SDA partly because it is focused on an interorbital regime, Lt. Gen. Phillip Garrant, commander of SSC, told reporters March 3 at the Air and Space Forces Association’s Warfare Symposium in Aurora, Colorado. Whereas the SSC is looking to connect its broader missile warning architecture with assets in LEO, medium Earth orbit and geosynchronous Earth orbit, the SDA’s architecture is completely based in LEO.

“It’s not duplicative work; it’s complementary work,” Garrant said, adding that industry should eventually dictate the standards that the U.S. military would adopt. “We’re certainly not discouraging it, but at the same time, we’ve got to push some of these other companies to build something as well.”

Europe is also investing heavily in laser-link communications. The European Space Agency in February signed a contract with Italy’s Thales Alenia Space to establish a satellite collector in LEO connecting different orbital layers via laser communications. In the program’s first phase, Kepler Communications developed 10 satellites for LEO.

Thales will build a relay satellite that receives data from other spacecraft and transmits it to ground stations or satellites in higher orbits. Mynaric is producing the OCTs, and Mbryonics the optical testbed facilities.