“The first Starlink satellites launched to polar orbit are equipped with laser crosslinks, a technology the company plans to add to other satellites next year.
SpaceX included 10 Starlink satellites on its Transporter-1 dedicated rideshare launch Jan. 24. Those satellites are the first in the Starlink constellation SpaceX has deployed to polar orbit, after winning Federal Communications Commission to do so Jan. 8.
In tweets after the launch, Elon Musk, founder and chief executive of SpaceX, said those satellites were equipped with laser intersatellite links. “These also have laser links between the satellites, so no ground stations are needed over the poles,” he said in response to one tweet about the launch.
Intersatellite links allow satellites to transfer communications from one satellite to another, either in the same orbital plane or an adjacent plane. Such links allow operators to minimize the number of ground stations, since a ground station no longer needs to be in the same satellite footprint as user terminals, and extend coverage to remote areas where ground stations are not available. They can also decrease latency, since the number of hops between satellites and ground stations are reduced.
SpaceX has tested intersatellite links on other Starlink satellites, although they are not in widespread use. During a September 2020 webcast of a Starlink launch, the company said it tested “space lasers” between two satellites, relaying hundreds of gigabytes of data. “Once these space lasers are fully deployed, Starlink will be one of the fastest options available to transfer data around the world,” the company said at the time.
Musk, in another tweet, said SpaceX would roll out laser intersatellite links on other Starlink satellites next year. “All sats launched next year will have laser links. Only our polar sats have lasers this year & are v0.9,” he said.”