DMSP-5D1 F4

DMSP-5D1 (Defense Meteorological Satellite Program Block 5D1) was the ninth version of the military meteorological satellites of the Defense Meteorological Satellite Program. These version was also known as AMS (Advanced Meteorological Satellite). This series introduced a new 3-axis stabilized bus with integrated propulsion system, so that the satellite itself acted as an upper stage for the launch vehicle. It consisted of a Star-37XE and a Star-37S motor and the ISS (Integrated Stage System) control system featuring four axial hydrazine thrusters. Power was supplied by a single, articulated 8-segmented solar array.