High Quality Content by WIKIPEDIA articles! Unmanned spaceflights to the International Space Station (ISS) are made primarily to deliver cargo, however several Russian modules have also docked to the outpost following unmanned launches. Resupply missions typically use the Russian Progress spacecraft, European Automated Transfer Vehicles, and Japanese Kounotori vehicles. The primary docking system for Progress spacecraft is the automated Kurs system, with the manual TORU system as a backup. ATVs also use Kurs, however they are not equipped with TORU. Progress and ATV can remain docked for up to six months. Kounotori spacecraft rendezvous with the station, before being grappled using Canadarm2, and berthed at the nadir port of the Harmony module for one to two months. As of 2012, Progress spacecraft have flown most of the unmanned missions to the ISS.