NASA's National Aeronautics and Space Administration is soliciting white papers for the 2025 Request for White Papers: SBIR Phase II Sequential Awards, aimed at small businesses with prior NASA SBIR Phase II awards. The initiative seeks to evaluate existing technologies that demonstrate potential for risk reduction and align with NASA's objectives, with funding amounts ranging from $2.5 million to $4 million for selected proposals. This opportunity is critical for advancing technologies in three specific Technical Need Areas (TNAs): Entry, Descent, and Landing Flight Instrumentation, Nuclear Electric Propulsion Subsystems, and Lunar Surface Power Management and Distribution Technologies. Interested firms must submit their white papers electronically by September 23, 2024, and can contact Kenneth E. Albright at kenneth.e.albright@nasa.gov or Steven Brockway at steven.m.brockway@nasa.gov for further information.