T-Mobile successfully uses Starlink satellites to send emergency alerts

For the first time, T-Mobile has used SpaceX's Starlink cellular satellites in space to send an emergency alert to a phone on the ground.

The alert was sent on September 5 as T-Mobile launched a test to demonstrate how Starlink satellites could deliver emergency evacuation instructions to users on the ground without relying on traditional cell towers.

“The alert was transmitted 217 miles into space, where it was received by one of the 175+ Starlink satellites currently in low Earth orbit, effectively acting as cell towers in space,” T-Mobile says. “The alert was then transmitted to a geographic area affected by the hypothetical evacuation request and received by a T-Mobile smartphone.”

“Overall, it took emergency responders just seconds to queue an emergency message and transmit that message to users on the ground via Starlink satellites,” the network operator adds.

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The wireless carrier touted the achievement on Wednesday after both SpaceX and T-Mobile called on the FCC to clear the satellites for commercial operation. The goal is to roll out Starlink functionality to cell phones later this fall, allowing T-Mobile to serve users in dead zones.

Previous tests by SpaceX show that the same satellites can enable video calls, 17 Mbps download speeds and other internet features on devices like iPhones, Google Pixels and Samsung Galaxy phones. But despite this technological achievement, rival carriers like AT&T and Verizon have called on the FCC to put restrictions on Starlink technology outright, fearing it could cause radio interference on their own networks.

In a possible attempt to influence regulators, both SpaceX and its CEO Elon Musk have told the FCC and the public that cellular Starlink satellites would benefit all users because they could theoretically send free emergency alerts to any phone, regardless of carrier. On Wednesday, T-Mobile took the same view, saying the “emergency alerts would work for everyone – even customers of Verizon, AT&T and other wireless carriers would receive critical emergency alerts.”

The carrier also noted that its satellite capability will enable it to “bring critical emergency messages to over 500,000 square miles of land that is currently inaccessible by ground-based cell towers.”

T-Mobile's statement comes a day before a rival cellular satellite service is set to reach its own milestone. On Thursday morning, AST SpaceMobile – whose major investors include AT&T and Verizon – plans to launch its first commercial satellites into space, which will also function as cell towers. Once the satellites are fully deployed, AST SpaceMobile plans to begin beta testing as early as December, pending regulatory approval.