Over the next several years, the Department of Defense (DoD) will launch the last of its weather satellites, which it uses to plan military operations and generate weather forecasts. Long-running efforts to develop replacements for those satellites encountered schedule and cost difficulties, and in December 2011, the Congress directed DoD to cancel its latest program and to prepare for a follow-on program. DoD’s plans now call for a new development effort, but it has not yet determined the capabilities it wants in that satellite. In this paper, the Congressional Budget Office (CBO) examines three different satellite design concepts that DoD might consider and compares the cost and capability of those designs. The paper also discusses alternative approaches that DoD might take, such as fielding single instruments on several small satellites instead of several instruments on a single satellite and foregoing a new generation of military weather satellites altogether and instead relying on other sources for weather data.