Soyuz 23

Soyuz 23 was a Soviet crewed spaceflight launched on October 14, 1976. The mission's primary objective was to dock with the Salyut 5 space station and conduct scientific research. However, the mission was plagued by complications, ultimately resulting in an emergency landing in Lake Tengiz, Kazakhstan.

The crew consisted of Commander Vyacheslav Zudov and Flight Engineer Valery Rozhdestvensky. Their docking attempt with Salyut 5 was unsuccessful due to a faulty Igla automatic docking system. Repeated attempts to manually dock also failed.

With dwindling power reserves and life support consumables, mission control ordered an emergency return to Earth. The descent capsule landed off-target in the partially frozen Lake Tengiz during a blizzard and at night. The capsule was submerged, and the crew faced a perilous situation as the spacecraft's hatch was below the waterline, preventing immediate rescue.

Rescue efforts were hampered by the severe weather conditions and the difficult terrain. It took approximately nine hours for recovery teams to reach the submerged capsule using helicopters and frogmen. The cosmonauts were eventually extracted, suffering from hypothermia but otherwise unharmed.

Soyuz 23 was a significant event in the Soviet space program, highlighting the risks involved in spaceflight and the importance of robust backup systems. The mission also demonstrated the resourcefulness and resilience of the Soviet space program in dealing with unexpected emergencies. While failing to achieve its primary objective of docking with Salyut 5, the mission provided valuable lessons learned for future spaceflights. The spacecraft itself was recovered and studied to determine the cause of the docking failure.