The Vulcan device consisted of two major units. The first unit included various welding devices and a turn-table with samples of metals to be welded. The second unit consisted of an electric power pack, a protective shield which covered the welding unit, and a remote control console.
Finally, on April 25, 1969 during a meeting of the Soyuz State Commission, it was decided that the solo and docking flights outlined for 1969 by design bureau OKB-1 would be combined into a joint flight of three spacecraft. The plan was to fly Soyuz 6, 7, and 8 together in August of 1969; Soyuz 7 and 8 would dock and 6 would rendezvous with the docked pair and take pictures of it as well as perform a welding experiment.
Georgy Stepanovich Shonin, Commander of Soyuz 6
Valeri Nikolayevich Kubasov, Flight Engineer for Soyuz 6