Reusability changes the launch math; phased arrays change the payload math. The single most important design choice in a modern communications satellite is not whether it carries a dish or an array — it is that almost all of them now carry arrays. Understanding why explains most of what a constellation can and cannot do.
Start with the dish, because it is intuitive. A parabolic dish collects or focuses radio energy along one axis; to aim it somewhere else, you physically move it. That is fine for a single high-value link — a ground station tracking one satellite, or a GEO satellite holding one beam over one region. But a dish points at one thing at a time, and it does so with motors that wear out.
A phased array is a different machine. It is a flat panel covered in many small radiating elements, each fed a copy of the signal with a precisely controlled timing offset, or phase. By tuning those offsets, the array forms a beam and steers it electronically — and, crucially, it can form several beams at once, each aimed independently, switching targets in milliseconds. AST SpaceMobile's FY2025 10-K describes a constellation built around exactly this kind of large array.
The mass budget and the business model meet here. A constellation serving many users across a wide footprint needs to illuminate many small coverage cells simultaneously and hand users off as satellites streak overhead. Only electronic beam-steering can do that at the required speed. A satellite full of motorized dishes could not keep up, and would weigh and fail in ways a solid-state array does not.
There is a cost to the elegance: phased arrays are power-hungry and computationally demanding, because forming and steering beams is real-time signal processing, not mechanics. That is part of why constellation operators raise so much capital — the satellites are sophisticated, and the prospectus supplements that fund them describe arrays large enough to make the physics work. These documents were surfaced via EdgarBeast and recorded on sec.gov.
The takeaway for reading any constellation story: when an operator boasts about its antenna, it is really telling you how many beams it can aim, how precisely, and how fast it can reconfigure them. That capability — not the rocket, not the orbit — is what determines how many customers a satellite can actually serve.