'Largest ever' commercial comms array deployed in LEO

Satellite manufacturer AST SpaceMobile has reached a milestone in its mission to build the first and only global cellular broadband network in space to operate directly with standard mobile phones, having successfully completed deployment of its test satellite and communications array, BlueWalker 3 (‘BW3’), in orbit. The goal of the network is to eliminate the connectivity gaps faced by today’s five billion mobile subscribers and finally bring broadband to the billions who remain unconnected.

BW3 is being billed as the largest ever commercial communications array deployed in LEO, spanning 64.38 m² in size — a design feature critical to support a space-based cellular broadband network — with an expected field of view of over 776,996 km² on the surface of the Earth. It is designed to communicate directly with cellular devices via 3GPP standard frequencies at 5G speeds, testing the technologies that AST SpaceMobile will need for its planned commercial service.

The satellite comprises a large, flat, thin array built from identical components called Microns; solar cells collect energy on one side, and on the other side, many small antennas form a phased array. These antennas work together to form tight communications beams, which are an efficient way to push a strong signal from space to Earth. These beams of coverage are similar to those created by a terrestrial cell tower, and should help ordinary phones ‘see’ BW3 without any modifications. The array can also ‘hear’ mobile phone signals hundreds of kilometres away.

BW3 was designed to fold into a cube, which was sent into low Earth orbit by rocket back in September. AST SpaceMobile engineers subsequently contacted the satellite, oriented it to regulate power and temperature, and eventually directed it to unfold on 14 November. The unfolding process was powered by energy stores in hinges that connect the Microns together, and was made possible by years of R&D, testing and operational preparation.

AST SpaceMobile has scheduled a rigorous test program to ensure BW3 is doing everything it needs to do, and aims to work with mobile network operators (MNOs) to fine-tune ground equipment, software and operations. An experimental licence from the US Federal Communications Commission allows the company to test in Texas and Hawaii, with further testing planning across all six inhabited continents. If all goes well, the company hopes to make the first cellular broadband connections from a satellite directly to ordinary mobile phones — a major step towards building the world’s first space-based cellular broadband network.

“Every person should have the right to access cellular broadband, regardless of where they live or work. Our goal is to close the connectivity gaps that negatively impact billions of lives around the world,” said Abel Avellan, Chairman and CEO of AST SpaceMobile.

“The successful unfolding of BlueWalker 3 is a major step forward for our patented space-based cellular broadband technology and paves the way for the ongoing production of our BlueBird satellites.”

AST SpaceMobile has agreements and understandings with MNOs globally that have over 1.8 billion existing subscribers, including a mutual exclusivity with Vodafone in 24 countries. Interconnecting with AST SpaceMobile’s planned network will allow MNOs — including Vodafone Group, Rakuten Mobile, AT&T, Bell Canada, MTN Group, Orange, Telefonica, Etisalat, Indosat Ooredoo Hutchison, Smart Communications, Globe Telecom, Millicom, Smartfren, Telecom Argentina, Telstra, Africell, Liberty Latin America and others — the ability to offer extended cellular broadband coverage to their customers who live, work and travel in areas with poor or non-existent mobile coverage, with the goal of eliminating dead zones with cellular broadband from space.

“We want to close coverage gaps in our markets, particularly in territories where terrain makes it extremely challenging to reach with a traditional ground-based network,” said Luke Ibbetson, Head of Group R&D, Vodafone and an AST SpaceMobile director. “Our partnership with AST SpaceMobile — connecting satellite directly to conventional mobile devices — will help in our efforts to close the digital divide.”

Tareq Amin, CEO of Rakuten Mobile and Rakuten Symphony and an AST SpaceMobile director, added, “Our mission is to democratise access to mobile connectivity; that is why we are so excited about the potential of AST SpaceMobile to support disaster-readiness and meet our goal of 100% geographical coverage to our customers in Japan. I look forward not only to testing BW3 on our world-leading cloud-native network in Japan, but also working with AST SpaceMobile on integrating our virtualised radio network technology to help bring connectivity to the world.”

Image caption: The 64.38 m² array on Blue Walker 3 has successfully completed deployment.