The test alert was delivered via the Starlink satellites in a process that took seconds, says T-Mobile, which is preparing to launch a cellular satellite system with SpaceX this fall.

PT on Thursday, September 5th, T-Mobile initiated a test alert for a hypothetical evacuation notice,” according to T-Mobile. “The alert was sent 217 miles into space where it was received by one of the more than 175 Starlink direct-to-smartphone satellites currently in low earth orbit that effectively function as cell towers in space.

Today, T-Mobile (NASDAQ: TMUS) announced that it successfully sent and received - for the first time ever in the U.S. - a wireless emergency alert (WEA) via satellite. The breakthrough opens up the 500,000 square miles of lightly populated, mountainous and/or uninhabitable land across the country to critical, life-saving emergency alerts.