PROGRESS-M 55 (Progress M-55) is a cargo satellite launched on December 21, 2005, from the Tyuratam Space Center, Launch Pad LC1, using the Soyuz-U-PVB launch vehicle. The spacecraft measures 7.9 meters in length with a diameter of 2.7 meters and has a span of 7.9 meters. It was manufactured by PROGT for RKKE and carries a dry mass of 4,794 kilograms, with a launch mass of 7,285 kilograms. The satellite is equipped with two deployable fixed solar arrays and batteries for power. Its design includes a sphere, cone, cylinder, and two panels, with a propulsion system powered by the 11D428A motor. The mission purpose was to deliver cargo using the Progress 7K-TGM No. 355 payload configuration.