CEO Abel Avellan and an AST SpaceMobile engineer completing test calls in Texas. Photo: Business Wire/AST SpaceMobile

AST SpaceMobile successfully made two-way voice calls to unmodified smartphones using the BlueWalker 3 satellite — a critical milestone for the company’s test satellite. AST SpaceMobile announced Tuesday that the first voice call was from Midland, Texas to Rakuten in Japan over AT&T spectrum, using a Samsung Galaxy S22 smartphone.

The company claims this is the first call of its kind from an unmodified cell phone. Engineers from Vodafone, Rakuten, and AT&T worked with the company on the testing. 

“Achieving what many once considered impossible, we have reached the most significant milestone to date in our quest to deliver global cellular broadband from space,” commented Abel Avellan, chairman and CEO of AST SpaceMobile. 

The test used AST SpaceMobile’s BlueWalker 3 test satellite, launched in September 2022. It has a massive 693-square-foot array that is designed to communicate directly with unmodified cell phones using 3GPP standard frequencies. 

AST SpaceMobile said it has also done initial compatibility tests on different smartphones and devices, exchanging subscriber identification module (SIM) and network information directly to BW3. The company also said additional testing on the smartphone uplink and downlink signal strength confirms that the technology can support “cellular broadband speeds and 4G LTE / 5G waveforms.”

Vodafone, Rakuten, and AT&T applauded the test. 

“30 years after Vodafone sent the world’s first text message, we supported AST SpaceMobile in successfully making the first ever direct-to-smartphone test call using satellite communications. This is just the start. As a lead investor in AST SpaceMobile, we will continue to break technological boundaries by connecting many more millions of people across the planet when the service becomes commercially available,” commented Margherita Della Valle, Vodafone Group chief executive. 

It will be some time before AST SpaceMobile enters commercial service, however. It won’t start commercial service until it has its next satellites, called BlueBird Block 1 satellites, in orbit. The first BlueBird satellites were expected to launch this year but are now expected to launch in the first quarter of 2024. The company needs to raise an additional $550 million to $650 million to build and launch the complete set of its BlueBird Block 2 satellites. 

There is increasing momentum around cellular direct-to-satellite connectivity in the satellite industry, with the new iPhone 14 connecting to Globalstar’s satellites for emergency messaging, Iridium working with Qualcomm, and other developments from Lynk.