Soyuz 6 was the first of a three-flight mission with Soyuz 7 and Soyuz 8. The main goal of Soyuz 6 was to demonstrate welding capabilities in space and film the docking of Soyuz 7 and Soyuz 8. The docking systems on all three Soyuz failed, preventing the main point of the three flight joint mission. During welding demonstrations, the crew nearly killed themselves by accidentally cutting into and nearly through the hull of Soyuz.