Space Exploration Technologies Corp. (NASDAQ:SPCX) agreed to acquire Grain Management's nationwide 800 MHz spectrum portfolio for an undisclosed amount, giving Starlink Mobile a low-band component for a hybrid satellite-and-terrestrial wireless network. SpaceX said the spectrum would help signals penetrate walls and other obstacles and support connectivity indoors, outdoors and in cellular dead zones after final Federal Communications Commission approval. The acquisition addresses a technical gap in SpaceX's plan to become a major U.S. mobile carrier and complements its global 2 GHz mid-band holdings. The strategy would allow Starlink Mobile to connect ordinary mobile devices through satellite and terrestrial spectrum, while the company's Gen2 constellation is intended to provide additional capacity. The announcement weighed on established wireless operators, with AT&T, Verizon Communications and T-Mobile US falling sharply in after-hours trading, while SpaceX shares rose 2.56% to $164.68. The expansion adds competitive pressure to AST SpaceMobile's carrier-dependent direct-to-device model. Earlier FCC action allowed SpaceX to pursue a constellation connecting directly to ordinary phones using spectrum it already owns, though that bureau authorization remained subject to possible full-commission review. Investors are watching final FCC and transaction approvals, Starlink's launch and direct-to-cell progress, and potential Japanese government support for AST SpaceMobile's partnership with Rakuten.