Starlink, SpaceX's internet connectivity constellation, received a big upgrade.
On Sunday, CEO Elon Musk confirmed a mysterious black pipe, spotted on the latest Starlink satellites, is a laser link. The feature could bring internet access to more places. The 10 satellites sporting the upgrade launched at 10 a.m. Eastern on January 24, from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida.
The upgrade could dramatically improve Starlink's overall reach and help it meet its goals. Satellite internet promises connections from almost anywhere with a view of the sky, but existing services like Viasat and HughesNet are plagued with slower-than-advertised speeds and long response times. SpaceX aims to solve this by orbiting the satellites much closer to the ground, at an altitude of 550 kilometers.
This also means launching a lot more satellites than other constellations. Since the first batch of 60 launched in May 2019, SpaceX launched 1,023 satellites. The company has applied for permission to launch up to 42,000 satellites. By comparison, there were around 5,000 satellites orbiting Earth in total at the start of 2019.
Starlink enables a user to access the internet by connecting their home router to a satellite dish outside. This is pointed at the sky to communicate with the satellites overhead. Each craft receives signals from a user, then connects to a giant SpaceX-operated ground station operated elsewhere. That enables access to the rest of the internet.
So what happens if a given satellite can't see a ground station? SpaceX's original plan was to use laser links between the satellites to find a pathway and connect to the rest of the internet. The first satellites lacked these links. In February 2020, Musk wrote on Twitter they weren't really that necessary:
"Direct links aren’t needed to offer service. Starlink will initially bounce signals off ground/ocean relays to get from 🛰 to 🛰."
By the end of 2020, SpaceX had started offering limited beta tests for customers in the United States, United Kingdom, and Canada using the laser-less constellation. Users on the "Better Than Nothing" beta reported speeds of around 150 megabits per second.
The 10 new satellites are the first in the constellation to use laser links. They launched as part of the Transporter-1 rideshare flight, which packed 143 satellites in total as part of the company's first SmallSat Rideshare mission. SpaceX declared it the most spacecraft ever deployed on a single mission.
The laser-equipped Starlinks were also the first to deploy to a polar orbit. Musk explained that these will be the only satellites to launch this year with laser links, which he dubbed "v0.9." All satellites launched next year are expected to feature laser links.
The Inverse analysis — Laser links make a lot of sense. A November 2018 animation produced by University College London's Mark Handley showed how the links could be faster than a fiber optic connection, in part because the speed of light is around 50 percent faster through a vacuum than through glass.
So why not just roll them out across the board? The main issue is cost, as the team explained on Reddit in November 2020: "Bringing down the cost of the space lasers and producing a lot of them fast is a really hard problem that the team is still working on."
The ongoing beta test shows Starlink works without the links. As it stands, the beta speeds fall far short of SpaceX's goals to reach one gigabit per second. A slide from a SpaceX presentation this month showed the company's long-term ambition is 10 gigabits per second, plus a resilient network with "multiple routing options to every Starlink and Gateway."
With satellites from April 2020 only expected to orbit for around three to four years, expect SpaceX to roll out updates to new craft as it sees fit — news that will also please astronomers irritated with the highly-visible early models.