424B3

AST SpaceMobile appointed Shanti Gupta as Chief Accounting Officer effective September 15, 2021, bringing over 20 years of finance and accounting experience from Ernst & Young, Deloitte, and KPMG, with compensation of $250,000 base salary plus 250,000 restricted stock units. The company simultaneously filed this prospectus supplement dated September 21, 2021 to update its registration statement covering the potential issuance of approximately 141.5 million shares of Class A common stock in exchange for ownership units in its parent entity AST & Science, LLC, with the stock trading at $11.55 per share on Nasdaq under ticker ASTS.