The U.S. Space Force was established on Dec. 20, 2024, when the National Defense Authorization Act was signed into law, creating the first new branch of the armed services since 1947. The establishment of the USSF resulted from widespread recognition that space is a national security imperative.

Earth-to-space weapons pose the greatest current danger and include direct-ascent anti-satellite weapons, which the United States, China, India and Russia have all tested, as well as directed-energy lasers and jammers.