The Department of Defense, specifically the United States Air Force, is seeking innovative solutions through the Small Business Innovation Research (SBIR) program for the development of acoustic recorders designed for persistent high-altitude sensing. The objective is to create a lightweight, low-power acoustic sensor and accelerometer package that can be deployed on high-altitude balloons (HABs) to detect and track various phenomena, including aircraft, ships, and natural events such as explosions and earthquakes. This initiative aims to enhance surveillance and monitoring capabilities at altitudes where traditional ground-based or satellite sensors may be less effective, addressing the current lack of high-quality, compact acoustic sensors suitable for extreme high-altitude conditions. Interested parties should note that the solicitation is open from May 15, 2024, to June 12, 2024, with proposals due by the latter date. For more information, please visit the official SBIR website at https://www.dodsbirsttr.mil/topics-app/.