They not only had to wait until the space station steered into the proper lane for the Soyuz, but they had to pick a time when the distance between the station and the Soyuz once the Soyuz reached orbit was at a minimum.

FORBES: How Astronauts Got From Kazakhstan To The Space Station In Six Hours

On 18 August, the week before the loss of the space station mission, a Proton vehicle failed to put a communications satellite in its proper orbit.

BBC: Another Soyuz rocket launch fails

On 18 August, the week before the loss of the space station mission, a Proton rocket failed to put a communications satellite in its proper orbit.

BBC: Soyuz back in service after failed launch