The Missile Defense Agency (MDA) is seeking innovative interceptor seekers for missile defense in the upper atmosphere as part of its Small Business Innovation Research (SBIR) program. The objective is to develop advanced seekers that can effectively detect missile threats, withstand extreme conditions, and transition from standby to operational states rapidly, while being compact and cost-effective. This initiative is crucial for enhancing the United States' layered missile defense system, which protects against missile attacks throughout all flight phases. Proposals for Phase II are expected to demonstrate a Technology Readiness Level (TRL) of at least 4 and must be submitted by September 24, 2025, with further details available at the MDA's SBIR website.