Return is a sequence

A returning Soyuz first separates from its destination and establishes a safe departure. A deorbit maneuver then changes its trajectory toward atmospheric entry. Departure and deorbit are related, but they solve different problems: clearance from the station and a return path to Earth.

A photograph of an undocked vehicle does not prove that its deorbit maneuver has already happened. Describe the phase shown and use the mission record to establish the subsequent sequence.

Module separation leaves the protected descent cabin. Atmospheric flight removes orbital energy; parachutes slow the later descent; the landing system reduces the final impact. Each step depends on earlier conditions being suitable.

The orbital module is not a second returning crew capsule. It and the service section are discarded. Confusing the full orbital spacecraft with the small parachute-borne object obscures why the design separates functions among modules.

The image of Soyuz TMA-18M descending in March 2016 shows the return capsule beneath a parachute. It illustrates one phase, not the complete recovery operation. Ground personnel still have to reach the vehicle and help its occupants.

A useful final exercise is to follow one requirement through the sequence: breathable atmosphere for the crew, for example, must remain supported during undocking, entry and landing. The people are continuous even while the spacecraft discards hardware and changes operating modes.