The United States funds a massive, unitemized 'black budget' dedicated to researching and developing highly advanced, classified aerospace technologies.

A significant portion of military aerospace developments is shielded from public scrutiny through the Pentagon's classified 'black budget,' which reached an unprecedented $86 billion in fiscal year 2019. These funds are allocated to highly classified programs, such as Lockheed Martin's Skunk Works, to pioneer revolutionary aerospace engineering and low-observable platforms. Because these cutting-edge technologies are tested under extreme secrecy, their flight characteristics and visual signatures often mimic physics-defying anomalies to observers unaware of their domestic, classified origins.