This 18-day flight of Soyuz was a long duration test to see what a crew was capable of doing in space. It stands to this day as the longest flight of a human craft that did not dock to a space station. It was the first night launch of a human mission and was the first Soviet mission to examine the psychological effects of teamwork on prolonged, confined missions. This flight proved that spin-stabilization is detrimental to a space traveller's wellbeing and that attitude control thrusters should be used instead.