Kurs was the successor to the Igla system and today provides navigation beaconing for Russian space vehicles including the Soyuz spacecraft and Progress spacecraft. The main difference between both systems is that Igla requires the space station to collaborate in the docking maneuver by reorienting itself to point the docking port to the spacecraft, while Kurs allows to dock with a fully stationary space station. The main reason for this change was that Mir was to be a much bigger space station than the older Salyut, so the propellant consumption would be excessive. Kurs provided the automated docking system for all Russian spacecraft that docked with the Mir space station. When used for docking, the Soyuz or Progress vehicle broadcasts radar pulses from multiple antennas. The variation in strength between the antennas allows the system to compute relative position, attitude, and approach rate. The system is designed for automatic rendezvous and docking, but in an emergency cosmonauts may take command of the vehicle, either locally or from the International Space Station. After the dissolution of the Soviet Union in 1991, the Kurs system became the property ofUkraine; its manufacturer became a competitor in the space launch business with the Russian Federal Space Agency. Due to hard-currency problems, Kiev also raised the price of the Kurs system. Consequently, RKA sought to phase out its use in its vehicles. A test using the Russian TORU backup system to reduce reliance on Kurs, was responsible for the collision between Mir and Progress M-34 and the damage to the Spektr module, nearly causing Mir to be abandoned. After the collision and recovery, the next Progress ship had a failure of Kurs, and was docked successfully using the same TORU system.
Kurs-NA
The Kurs-NA docking system, requiring only one rendezvous antenna and using less power, replaces Kurs-A, which required five antennas. It was tested by Progress M-15M in July 2012 and by Progress M-21M in November 2013. It is used on the Progress MS.
ISS
ATV
The now Russian-built antenna part of the Kurs system also served as an independent and redundant docking monitoring system for the European Automated Transfer Vehicle. It served as an additional monitoring system and could not be used to control the approach or docking of ATV in any way.
Failures
On 15 December 2015 during the docking of Soyuz TMA-19M with the InternationalSpace Station the Kurs system mis-aligned the spacecraft and failed to dock, requiring a manual docking approach piloted by Soyuz Commander Yuri Malenchenko. This delayed the docking by 10 minutes. On 24 August 2019 during the docking of an uncrewed Soyuz MS-14 with the International Space Station the spacecraft failed to lock on to the Poisk Module port. The reason is the Kurs system failed on the Station side and failed to dock. Docking attempt was aborted until 27 August 2019.
