PROGRESS-MS 21

The Progress MS is the latest version of the Russian Progress spacecraft series, first launched in 2015. The "MS" stands for "modernized systems", reflecting upgrades primarily focused on the communications and navigation subsystems. An evolution of the Progress M spacecraft, the Soyuz MS features minimal external changes, mainly in the placement of antennas, sensors, and thrusters. It is used by Roscosmos for cargo spaceflight missions. Progress MS-01 conducted its maiden flight on 21 December 2015, heading to the International Space Station (ISS).