AST SpaceMobile’s operational strategy relies on a small constellation of very large satellites designed to deliver broadband, voice, and messaging services directly to unmodified devices. This approach differs significantly from competitors like Lynk, which utilise larger constellations of small satellites primarily targeted at messaging. The use of large satellites provides a specific technical advantage: they allow standard smartphones to browse the internet and receive high-speed data without requiring massive external antennas.
The core of this technology involves huge phased arrays that enable the high sensitivity and power levels necessary to support 4G LTE and 5G sub-6 standards. A prominent example is the BlueWalker 3 (BW3) test satellite, which features a phased array antenna covering 693 square feet to form and steer communication beams. In partnership with AT&T, this technology has already demonstrated the ability to reach download speeds of up to 14Mbit/s when sending 4G and 5G signals to Earth.
However, the size of these satellites introduces several challenges and risks:
- Space Debris: The massive surface area of satellites like BW3 presents an increased risk of space debris compared to smaller LEO satellites.
- Deployment Costs: Large satellites are significantly more expensive to deploy and operate, facing substantial size, weight, power, and cost (SWaP-C) limitations.
- Regulatory Scrutiny: Because these systems reuse terrestrial MNO spectrum from space, they require complex regulatory approvals and waivers to ensure they do not cause harmful interference to other systems.
To understand the difference in scale, consider the analogy provided in the sources: traditional small-satellite systems (like Iridium) provide limited services and require large antennas on phones, whereas a large-satellite approach (like AST SpaceMobile or Terrestar) enables standard, small smartphones to access full broadband and internet services.
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