We're already there, it's just a matter of provisioning LEO constellations and sorting out market-fit, although Starlink Direct-to-Cell (D2C) is probably the least enticing offering.

As it stands both ASTS and Lynk Global use 3GPP standards to allow standard, unmodified mobile phones to connect directly to cell towers in space, bridging terrestrial and non-terrestrial networks (NTN) without requiring special user equipment

https://www.satellitetoday.com/connectivity/2025/11/12/analy...

https://spacenews.com/the-merger-between-satellite-and-cellu...