Telesat Lightspeed Adds Military Ka-Band to Its LEO Constellation - at 0.5% Extra Cost

Key Takeaway

Telesat is adding dedicated military Ka-band spectrum to its Lightspeed LEO constellation before the first satellite has even launched. The modification - announced March 17, 2026 - adds 500 MHz of Mil-Ka spectrum across the first 156 satellites, devoting 25% of their total spectrum capacity to military and government use. The incremental cost is roughly $25 million, less than 0.5% of the total Lightspeed program budget. No schedule delay. The move reflects a significant shift in how LEO broadband operators are thinking about their market - government and defense demand is reshaping constellation design before commercial service even begins.

What Telesat Is Changing

Lightspeed is Telesat’s 198-satellite LEO constellation, designed to deliver enterprise-grade broadband at speeds up to 1 Gbps with sub-50ms latency globally. It targets a different market than consumer LEO services like Starlink - the focus is on telecommunications carriers, governments, and large enterprise customers.

The modification announced on March 17 allocates 500 MHz of Mil-Ka (military Ka-band) spectrum to the first 156 Lightspeed satellites. Mil-Ka is a protected frequency band used by military and government operators worldwide, with international agreements that allow interoperability between NATO and allied defense systems.

The Mil-Ka addition reallocates 500 MHz of user-link spectrum from commercial Ka-band to military Ka-band use - 25% of the total user-link spectrum per satellite. The gateway link is unaffected. The remaining 75% of user-link spectrum stays on commercial Ka-band.

Why Now, Before Launch?

Adding capabilities before launch is significantly cheaper than modifying deployed hardware - or launching entirely separate military satellites. Telesat CEO Dan Goldberg stated in the March 17 release that defense customers had been requesting sovereign, interoperable LEO connectivity for several years, and that adding Mil-Ka at this stage of production allows Telesat to address that demand without a meaningful impact on cost or schedule.

The defense satellite market has historically been dominated by dedicated military constellations - Wideband Global SATCOM (WGS) for the US, SKYNET for the UK, SYRACUSE for France. But these systems are expensive, slow to deploy, and aging. LEO constellations offering interoperable Mil-Ka capacity represent a new model: commercial operators providing military-grade connectivity as a service.

Telesat is positioning Lightspeed to capture this market alongside its commercial revenues. The company has held discussions with NATO members and allied defense departments across Europe and North America. Canada - a major Telesat shareholder through the government’s equity stake - has defense connectivity requirements that Lightspeed would directly serve.

The Competing Landscape

Telesat is not the first to see the military LEO opportunity. SpaceX has been awarded contracts for military Starlink use, including the US DoD’s Starshield program which uses modified Starlink hardware for classified government applications. Amazon Leo has also signaled interest in defense customers. Lightspeed’s differentiator is the dedicated Mil-Ka interoperability - rather than adapting commercial hardware, it integrates military-standard spectrum from the ground up.

The Delay: 2027 Shifts to 2028

Separately from the Mil-Ka announcement, Via Satellite reported on March 17 that Lightspeed’s commercial service entry has slipped from late 2027 to Q1 2028. The cause: a supply chain issue with application-specific integrated circuits (ASICs) from SatixFy, a key chipmaker for the satellite’s modem system.

SatixFy’s chips handle the software-defined radio processing in Lightspeed’s payload. A delay in the ASIC delivery cascades through satellite manufacturing, launch scheduling, and in-orbit testing. The two pathfinder satellites - which are still on track for a December 2026 launch - use an earlier chip revision that does not have the same supply constraint.

Timeline

What This Signals for the Industry

The Telesat announcement is part of a broader pattern: commercial LEO operators are baking government and military requirements into their constellation designs rather than treating defense as a separate, bolt-on capability.

The economics are compelling. Adding Mil-Ka to 156 satellites costs $25 million - roughly $160,000 per satellite. A dedicated military satellite might cost $300-500 million and take a decade to procure and launch. For NATO and allied governments, commercial LEO with embedded military-grade spectrum offers dramatically faster deployment and lower cost per megabit.

For Telesat specifically, the Mil-Ka addition diversifies revenue before the first satellite is even in orbit. Defense contracts tend to be long-term, high-value, and credit-stable - a useful counterweight to the volatility of commercial enterprise contracts. Whether it is enough to build a sustainable business alongside Starlink and Amazon Leo remains to be seen, but the July 2026 pathfinder launch will be the first concrete test of whether Lightspeed’s architecture delivers on its promises.