WSF-M1

WSF-M1 is the first satellite of the US Department of Defense Weather System Follow-on Microwave (WSF-M) programme, operated by the US Space Force. It was launched on 2024-04-11 and placed in a sun-synchronous orbit at 854 km altitude with a 06:00 descending equator crossing time.^[1] The Space Systems Command declared operational acceptance and initial operational capability (IOC) in April 2025.^[2] WSF-M1 carries a microwave imager payload that supports retrieval of ocean surface vector winds, tropical cyclone intensity estimation, sea-ice extent, soil moisture, snow water equivalent, and other environmental parameters.^[3] The satellite also hosts an energetic charged particle sensor covering the local space weather environment.^[3] The mission replaces environmental sensing capability previously provided by DMSP and supports global military weather and space-based environmental monitoring. Tasking is not available commercially.^[3]