The US Missile Defense Agency (MDA) recently issued a notice seeking innovative missile defense system technologies, architectures, and concepts aimed at developing low-cost interceptors or systems. The October 10 request for information (RFI) specifically calls for exploring technologies and prototypes to significantly reduce the cost per kill, excluding directed energy systems like high-energy lasers and high-power microwaves. The MDA expressed interest in using spiral development processes in two- to three-year sprints, beginning as early as 2025, to incrementally introduce new technologies and system builds for more affordable solutions. Final briefing papers for the RFI are due by November 15.