First two-way cellphone call made via satellite

AST SpaceMobile has announced the successful completion of the first-ever two-way voice calls to unmodified smartphones using the BlueWalker 3 satellite.
AT&T spectrum was used to make a voice call from Midland in Texas to the Rakuten mobile network in Japan using a Samsung Galaxy S22 smartphone using AST SpaceMobile’s BlueWalker 3 satellite.
Engineers from Vodafone, Rakuten and AT&T collaborated to test the service for the first time on 25 April 2023.
This has been touted as an important step to providing space-based GSM connectivity globally, including cellular broadband.
Facilitating smartphone calls using low-earth orbit satellites demonstrates the ability to offer a full suite of GSM services over a spaceborne cellular base station.

AST SpaceMobile team at the company’s Midland, Texas headquarters, with engineers from testing partners Vodafone, Rakuten and AT&T
AST SpaceMobile claims it is building the first and only space-based cellular broadband network accessible by standard smartphones.
They plan to deliver a global cellular network from space. In a briefing early last year, the company told investors that its network would eventually consist of 168 satellites.
This is the latest milestone in the company’s “goal of transforming the way the world connects,” said Abel Avellan, chairman and chief executive officer of AST SpaceMobile.
SpaceX, Inmarsat, and OneWeb are competitors who also have projects in the works to facilitate connections between low-earth orbit satellites and ordinary smartphones.
The key differentiator for AST SpaceMobile currently is that the company has facilitated a low-earth satellite connection without needing special software, ground terminals or hardware.

Render of AST SpaceMobile’s BlueWalker 3 test satellite currently in low Earth orbit

AST SpaceMobile engineers who supported the first voice calls over BlueWalker 3 outside company headquarters in Midland, Texas