Crew

• Nikolay Rukavishnikov (3)
• Georgi Ivanov (1)

Mission Parameters

• Mass: 6860 kg
• Perigee: 198.6 km
• Apogee: 279.2 km
• Inclination: 51.63°
• Period: 88.99 minutes

Mission Highlights

• Intercosmos mission to Salyut 6 with Bulgarian cosmonaut.
• Failed to dock with Salyut 6 due to main engine fault.
• Retro burn with reserve engine.
• Reentry acceleration of 10 G (98 m/s²).

Mission Description

Failed to dock with Salyut 6. Fired its main engine while closing to within 4km of the station. The burn, the sixth of the flight, was to have lasted 6s, but the engine shut down after 3s. The Igla docking system also closed down. The Proton crew aboard Salyut 6 reported flames shooting sideways from the main engine, toward the backup engine, at the time of the shutdown. The docking was called off and the Saturns made ready to return to Earth. The backup engine fired, but did not shut off at the end of the planned 188s burn. Rukavishnikov, uncertain if the engine operated at the proper thrust, determined to let it burn an additional 25s before shutting it down manually. As a result, Soyuz 33 made a steep ballistic reentry with acceleration up to 10G (98 m/s²). Because the service module was discarded after deorbit burn, examination of the failed engine was impossible. The Soyuz 33 crew was to have traded its spacecraft for Soyuz 32