Telesat, a long-time satellite provider, shared details of its low-earth orbit (LEO) technology in a press release today, touting optical links as well as Ka-band wireless connectivity, data processing “in space” and phased array antennas. The company calls its LEO offering Lightspeed.
Telecompetitor also got some additional information about Telesat LEO technology from Manik Vinnakota, director of product and commercial at Telesat, who answered some questions from us about Lightspeed plans via email.
Telesat expects to begin launching Lightspeed LEO satellites in approximately two years, with commercial services commencing in the second half of 2023.
Today’s release notes that the prime manufacturer for Telesat LEO satellites will be Thales Alenia Space.
Telesat LEO Technology
The non-geostationary satellite market is becoming an increasingly crowded one. SpaceX already has launched some of the satellites that will support its LEO offering. Also entering or eyeing the market are Amazon, LeoSat and Kepler Communications.
But while SpaceX and Amazon expect to target residential users, and perhaps businesses as well, Telesat is focused only on the enterprise market.
“Lightspeed is the only LEO network designed to serve the global requirements of enterprise (B2B) customers,” explained Vinnakota in the email to Telecompetitor. “We have designed our architecture and services to meet the low-latency, high throughput bandwidth requirements of leading Telecom, ISPs, Enterprise, Aeronautical, Maritime and Government users.”
Vinnakota added, however, that the company will be primarily serving service providers. The service providers, in turn, will serve end-user enterprises.
Like other LEO satellite operators, Telesat expects to provide lower latency in comparison with traditional geostationary satellite offerings, but there are some differences between its LEO technology and that of other providers.
Importantly, Telesat doesn’t expect to need as many satellites as other LEO operators. The company expects to provide global coverage using 298 satellites. In comparison, SpaceX expects to launch 4,400 LEO satellites to cover the U.S. and is expected to need another 7,000 to 8,000 to cover other parts of the world. Amazon also is expected to require thousands of satellites.
Asked how Telesat expects to use just 298 satellites, Vinnakota noted that Telesat Lightspeed satellites will fly in a combination of polar and inclined orbits, “optimized for complete global coverage and capacity distribution.”
Nearly 80 satellites will operate in the polar orbit and the remainder will have inclined orbits, which according to Vinnakota, brings more capacity into higher populated areas.
“The Telesat Lightspeed satellites will operate 1,000 – 1,350 km above Earth, so the satellites can see a wider footprint on the ground than those that are located at 500 km,” Vinnakota added.
According to a Telesat data sheet, the company’s satellites weigh 700 kilos – over 1500 pounds – which is substantially heavier than the satellites that some other LEO operators are offering. According to a CoBank report issued last year, some LEO satellites weigh 227 kilograms — about 500 pounds.
As Vinnakota explained, the extra weight comes from additional capabilities built into Telesat’s satellites.
“The additional size and power of the satellites allow us to host highly advanced technologies like Optical Inter-Satellite Links, Onboard processing, and sophisticated antennas that allow us to dynamically focus multiple Gbps into demand hot spots,” Vinnakota said.
While at least one other LEO operator – SpaceX – is using phased array antennas, I haven’t heard of any LEO operators other than Telesat touting optical connectivity which, according to the press release about Telesat LEO technology, enables satellites to talk to one another to create “a first-ever, highly resilient, flexible and secure, space-based IP network.”
I also haven’t heard other LEO operators talking about data processing in space, which according to Telesat, provides greater traffic routing flexibility and eliminates gateway hops.
According to Telesat, Lightspeed will have a combined capacity of 15 Tbps and will offer up to 7.5 Gbps to a single terminal or up to 20 Gbps to a single hotspot site, such as a remote community, airport hub or seaport.
Last year, we reported that Telesat had joined C Spire’s rural consortium, which aims to spur broadband deployment in rural areas. That announcement noted that Telesat expected to sell LEO connectivity to other providers to support backhaul connectivity.
