Soyuz 23 was intended to carry cosmonauts Vyacheslav Zudov and Valeri Rozhdestvenski to the Salyut 5 space station, presumably on an Almaz military mission. Although the Soyuz reached the station, a malfunction of the docking system did not allow a docking, similar to the problem experienced by Soyuz 15. Once again, by the time the automatic system had failed, there was no more fuel left for a manual docking and the mission had to be abandoned.

The spacecraft experienced a remarkable and near-catastrophic return to Earth. It descended onto a frozen lake in the middle of a snowstorm. The parachutes quickly filled with water, and dragged the capsule and its crew beneath the surface. Numerous attempts by recovery teams to reach it by amphibious vehicle failed. Inside the capsule, the heating had to be turned down in order to conserve power. Eventually, swimmers attached a cable to the capsule that allowed it to be dragged clear of the lake by a helicopter. The recovery team was surprised to find the crew still alive.

Crew

• Vyacheslav Zudov (1)
• Valeri Rozhdestvensky (1)

Mission Parameters

• Mass: 6760 kg
• Perigee: 239 km
• Apogee: 269 km
• Inclination: 51.6°
• Period: 89.5 min