Its main objective was to investigate the atmosphere on the station to see if it had become toxic and had an effect on the crew of the Soyuz 21 contributing to the problems they had at the end of their flight.
Its main objective was to investigate the atmosphere on the station to see if it had become toxic and had an effect on the crew of the Soyuz 21 they had at the end of their flight. This Soyuz 21 was contributing to the problems.